Base by Base

413: Rpc34 WH2 dynamics in RNA polymerase III

Gustavo Barra — Sun, 12 Jul 2026 10:29:14 +0000

Wu J-S et al., PNAS - A PNAS study using smFRET and nano-positioning triangulation maps dynamic positioning of the Rpc34 WH2 domain in yeast Pol III elongation complexes and presents a thiol-capping SPAAC labeling strategy to enable selective site-specific fluorophore attachment. Key terms: RNA polymerase III, Rpc34, winged helix, smFRET, bio-orthogonal labeling.

Study Highlights:
Using smFRET with ALEX and nano-positioning triangulation, the authors show Rpc34 WH2 occupies three discrete positions across the Pol III DNA-binding cleft and dynamically interconverts among them. A bio-orthogonal labeling workflow—azido-UAA incorporation plus SPAAC with thiol-capping—enabled selective labeling in the cysteine-rich complex. Maf1 binding locks WH2 into the upstream/distal state, validating positional assignments, and HMM dwell-time analysis revealed ordered transitions that proceed through the middle state with characteristic lifetimes. These results indicate Rpc34 WH2 engages the elongation complex via transient, weak DNA and protein contacts, with potential roles in bubble stabilization and rapid reinitiation.

Conclusion:
Rpc34 WH2 is a mobile, multifunctional cleft-associated module that occupies three ordered positions to transiently engage the Pol III elongation complex, and the thiol-capping SPAAC labeling approach provides a robust route for smFRET studies of large native assemblies.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Dynamic positioning of Rpc34 winged helix in RNA polymerase III elongation complex for its stability with implications for reinitiation

First author:
Wu J-S

Journal:
PNAS

DOI:
10.1073/pnas.2601775123

Reference:
Wu J-S, Chang W-H, et al. Dynamic positioning of Rpc34 winged helix in RNA polymerase III elongation complex for its stability with implications for reinitiation. Proc Natl Acad Sci U S A. 2026;123(27):e2601775123. doi:10.1073/pnas.2601775123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

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More at basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/base-by-base-413-rpc34-wh2-pol3-dynamics

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-07-12.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript portions describing Rpc34 WH2 dynamics, labeling strategy, three-state model, Maf1 effects, NPS localization, and rapid reinitiation implications, comparing to the original article.
- transcript topics: Rpc34 WH2 dynamics in Pol III elongation complex; smFRET labeling strategy (azido-UAA, SPAAC, MMTS); Maf1 regulation of WH2 mobility; Nano-positioning system (NPS) localization; Three-state model: distal, middle, proximal; Implications for rapid reinitiation and Pol III processivity

QC Summary:
- factual score: 9/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Rpc34 WH2 dynamically transitions among three discrete states across the Pol III DNA-binding cleft during elongation
- States are designated distal, middle, and proximal
- Maf1 stabilizes WH2 in the distal/upstream state, constraining mobility
- A bio-orthogonal labeling strategy (azido-UAA + SPAAC) with MMTS thiol-capping enables selective labeling of Rpc34 WH2
- NPS triangulation locates three spatial positions (distal, middle, proximal) across the DNA-binding cleft
- Mobility of Rpc34 WH2 is proposed to support rapid reinitiation and EC stability

QC Flagged Items (audited and not fully supported):
- Numeric claim uncertain: Dwell-time lifetimes: high-FRET ≈ 9.37 s, middle-FRET ≈ 3.12 s, low-FRET ≈ 1.41 s
Internal QC note: manual editorial review is recommended before publication.

QC result: Warning. Items above were flagged during automated QC; the editorial team reviewed them before release.

412: Fault Lines in Forensic Proficiency Testing

Gustavo Barra — Sun, 12 Jul 2026 10:10:04 +0000

Scurich N et al., PNAS - A concise breakdown of a PNAS perspective that analyzes forensic proficiency testing practices using the 2023 CTS firearms test as a case study. The authors identify test design and administration flaws—easy items, consensus scoring, handling of inconclusives, nonblind verification, shot‑to‑shot variability, and contextual bias—that undermine claims about examiner accuracy and the utility of reported error rates for courts and laboratories. Key terms: forensic proficiency testing, firearm identification, false positive rate, test design, cognitive bias.

Study Highlights:
The authors analyze CTS Test 23‑5262 and report a false‑positive rate of about 20% for bullet comparisons, highlighting broader concerns. They identify structural issues in proficiency testing including ceiling effects from easy items, inconsistent scoring of inconclusives, reliance on consensus rather than ground truth, and nonblind verification. The paper argues these features confound examiner performance with test properties, limiting the tests’ ability to estimate operational error rates and inform court decisions. The authors recommend better test design, blind verification, confidence ratings, and use of objective metrics to improve validation and lab practice.

Conclusion:
Current forensic proficiency testing practices can conceal fundamental weaknesses in examiner performance and test design; systemic, evidence‑based reform is needed to provide courts and laboratories with meaningful estimates of reliability and to reduce risks of wrongful outcomes.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Assessing the foundations of forensic identification evidence: A critical examination of proficiency test design and results

First author:
Scurich N

Journal:
PNAS

DOI:
10.1073/pnas.2528192123

Reference:
Scurich N, Albright TD. Assessing the foundations of forensic identification evidence: A critical examination of proficiency test design and results. PNAS. 2026; Vol.123:e2528192123. doi:10.1073/pnas.2528192123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/fault-lines-forensic-proficiency-testing

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-07-12.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript sections describing CTS proficiency testing (Test 23-5262), the reported false-positive rates, consensus scoring and inconclusives, out-of-class eliminations, shot-to-shot variability and reproducibility, contextual bias and NIBIN leads, nonblind verification, signal detection theory as reform, a
- transcript topics: CTS proficiency testing overview and purpose; CTS Test 23-5262 design and ground truth; False-positive rate findings (around 20%; 19.2% excluding item 4; 22% at least one false positive); Consensus scoring and handling of inconclusives; Out-of-class eliminations (Item 4) and associated errors; Class characteristics and reproducibility concerns across test sets

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- CTS Test 23-5262 false-positive rate ~20%
- Excluding item 4 yields ~19.2% false positives
- Approximately 22% of examiners made at least one false positive
- Item 4 was an out-of-class elimination; 1.5% failed; one called it an Identification; four called inconclusive
- Bullets from the same gun show shot-to-shot variability; test sets differed in marking/clarity
- NIBIN leads can prompt confirmation and influence examiner judgment

QC result: Pass.

411: EKV cells and the Human Prion Assay: a scalable platform for sCJD infectivity

Gustavo Barra — Thu, 09 Jul 2026 07:22:31 +0000

Nihata A et al., PNAS - This PNAS study describes the development of EKV, a humanized dividing cell line that propagates bona fide sporadic CJD (sCJD) prions, and the Human Prion Assay (HPA), a cell-based method that quantifies infectivity with sensitivity comparable to transgenic mouse bioassay while enabling rapid therapeutic screening. Key terms: sCJD, EKV cells, Human Prion Assay, prion infectivity, anti-PrP antibody.

Study Highlights:
The authors engineered EKV cells by reconstituting CAD5 PrP-knockdown cells with human PrP (V129) and iterative single-cell cloning to enrich prion susceptibility. EKV cells propagate de novo infectious sCJD prions that reproduce strain-specific pathology when transmitted to humanized Tg152c mice. The Human Prion Assay (HPA) using EKV cells quantifies sCJD infectivity across a wide dynamic range with sensitivity comparable to mouse bioassay but in weeks rather than years. Persistently infected iEKV clones can be cured by the anti-PrP monoclonal antibody ICSM18, validating the platform for high-throughput therapeutic screens.

Conclusion:
EKV cells and the HPA provide a renewable, scalable, and faster alternative to animal bioassays for measuring authentic human sCJD infectivity and for screening and validating anti-prion therapeutics, while retaining strain-specific biological properties.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
A scalable, dividing cell model for the robust propagation and quantification of human sporadic Creutzfeldt–Jakob disease prions

First author:
Nihata A

Journal:
PNAS

DOI:
10.1073/pnas.2600341123

Reference:
Nihata A, Collinge J, Linehan J, Brandner S, Mead S, Schmidt C, Rayner MLD, Jat PS, Arora P, et al. A scalable, dividing cell model for the robust propagation and quantification of human sporadic Creutzfeldt–Jakob disease prions. PNAS. 2026;123(27):e2600341123. doi:10.1073/pnas.2600341123.

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/ekv-human-prion-assay

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-07-09.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Substantive audit focused on EKV cell development and validation, in vitro propagation of human sCJD prions, HPA implementation and benchmarking against mouse bioassay, drug-screening demonstration, and documented limitations (codon 129 mismatch, occult infectivity).
- transcript topics: Prion biology and strain concepts (PRNP codon 129 polymorphism); Historical barriers to human prion culture and need for cell-based infectivity assays; Engineering EKV cells: CAD5-KDB3, human PrP V129, mouse signal peptide; Iterative single-cell cloning and enrichment to EKV; Infectivity validation via transmission to Tg152c mice; Development and validation of the Human Prion Assay (HPA)

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- EKV cells propagate de novo infectious human sCJD prions in culture
- Infectivity validated by transmission to Tg152c mice; 100% (18/18) succumbed to prion disease with incubation ~251 days
- Human Prion Assay (HPA) detects sCJD infectivity with titer ~5.66 logTCIU50/g, comparable to mouse bioassay ~5.88 logLD50/g
- HPA achieves detection across type 2 and 3 prion strains, with MM prions less efficiently propagated due to codon 129 mismatch
- Persistently infected iEKV lines (e.g., 1G2, 1E10) maintained infection over ≥15 passages; ICSM18 cures infection in iEKV
- Occult infectivity observed: KDB3 control exposed to brain homogenate still produced a single prion disease case after six passages

QC result: Pass.

410: Nucleotide diversity is a poor predictor of short-term adaptive potential

Gustavo Barra — Wed, 08 Jul 2026 07:50:32 +0000

Abson KL et al., PNAS - A cross-species synthesis and theory paper showing that simple molecular diversity metrics poorly predict short-term adaptive potential. The authors compiled >2,100 quantitative genetics estimates (evolvability and heritability) across ~193 eukaryotic species and compared them to nucleotide diversity (π) and microsatellite heterozygosity (He). They find nucleotide diversity explains only ~1.1% of interspecific variation in evolvability and that doubling π corresponds to a modest ~11.7% increase in evolvability. Theoretical models indicate this weak relationship is expected when trait variance is shaped by stabilizing selection, mutation rates, and effective population size dynamics. Key terms: nucleotide diversity, evolvability, adaptive potential, conservation genetics, microsatellites.

Study Highlights:
The authors compiled 2,113 evolvability estimates across 193 eukaryotic species and matched these to measures of nucleotide diversity (π) and microsatellite heterozygosity (He). They found no meaningful association between ln(IA) (evolvability) and ln(π): π explained ~1.1% of interspecific variation and doubling π predicts only an ~11.7% increase in evolvability. Microsatellite and nucleotide diversity were uncorrelated across species, and both molecular measures were weak predictors of quantitative genetic variation. Theoretical mutation–selection–drift models show weak associations are expected under stabilizing selection and when VA depends more on mutation rate and selection than on neutral diversity.

Conclusion:
Simple, genome-wide molecular diversity metrics (π, He) are poor predictors of short-term adaptive potential (evolvability); conservation assessments should not rely on these alone and should incorporate trait-based or functionally informed genomic data.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Nucleotide diversity is a poor predictor of short-term adaptive potential

First author:
Abson KL

Journal:
PNAS

DOI:
10.1073/pnas.2536181123

Reference:
Abson KL, Zijmers L, Mittell EA, Young EA, Postma E, Eyre-Walker A, Hadfield JD. Nucleotide diversity is a poor predictor of short-term adaptive potential. Proc Natl Acad Sci U S A. 2026;123(27):e2536181123. doi:10.1073/pnas.2536181123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/nucleotide-diversity-poor-predictor-adaptive-potential

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-07-08.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript's coverage of core scientific claims: relationship between π and IA, the π vs He relationship, functional variation (πN/πS), the theoretical basis (stabilizing selection), and conservation implications/policy directions.
- transcript topics: Adaptive potential and evolvability (IA) concept; Nucleotide diversity (π) as predictor of evolvability; Microsatellite diversity (He) and its relation to π and IA; Theoretical mutation–selection–drift framework and stabilizing selection; Functional variation (πN/πS) and its predictive power; Conservation policy implications and IUCN Red List considerations

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Nucleotide diversity explains 1.1% of interspecific differences in evolvability (IA).
- Doubling nucleotide diversity (π) corresponds to ~11.7% increase in evolvability (IA).
- Microsatellite diversity (He) and nucleotide diversity (π) are not significantly correlated across species.
- Functional diversity (πN/πS) shows little predictive power for IA; doubling πN/πS yields near-zero increase in IA.
- Slope of ln(VA) vs ln(π) is substantially less than 1 (β ≈ 0.160), consistent with stabilizing selection decoupling VA from π.
- Conservation implications: relying on simple molecular proxies (π, He) can misinform management; need genomic annotation and functionally informed approaches.

QC result: Pass.

409: A systems-level atlas of carbon-response transcriptional states in Escherichia coli

Gustavo Barra — Tue, 07 Jul 2026 05:03:48 +0000

Shin J et al., PNAS - This episode examines a large transcriptome compendium (PRECISE-NP881) that profiles E. coli K-12 MG1655 across 43 carbon substrates. Independent component analysis resolved 137 iModulons, including 25 carbon-catabolism modules that organize substrates into four activity-defined groups tied to growth rate, substrate chemistry, metabolic entry routes, and proteome allocation. The study integrates growth phenotyping, FBA/ME-modeling, targeted knockouts, and reanalysis of a starvation/refeeding time course to connect transcriptional modules to physiological context. Key terms: carbon response, iModulon, Escherichia coli, carbon catabolite repression, transcriptional regulatory network.

Study Highlights:
The authors assembled PRECISE-NP881 (881 transcriptomes) and used ICA to define 137 iModulons, 25 of which are carbon-catabolism modules whose activities cluster substrates into four groups. Faster-growing sugars showed limited CRP-linked remodeling while slower-growth, non-glycolytic substrates activated CRP-linked, NtrC-1, Propionate, and SgcABCEQX iModulons. Targeted knockouts (e.g., ΔprpC) demonstrated conditional growth defects on Group C/D substrates supporting a role for methylcitrate-mediated propionyl-CoA processing. Proteome-allocation modeling and projection of an independent starvation/refeeding dataset corroborated links between carbon-response modules, growth/stress physiology, and metabolite dynamics.

Conclusion:
The paper provides a quantitative atlas of carbon-responsive transcriptional states in E. coli, decomposing CCR into separable CRP-linked and substrate-specific modules and linking these modules to growth rate, metabolic context, proteome allocation, and conditional physiological relevance.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
A systems-level atlas of carbon-response transcriptional states in Escherichia coli

First author:
Shin J

Journal:
PNAS

DOI:
10.1073/pnas.2531884123

Reference:
Shin J, Son HF, Krishnan J, Hefner Y, Szubin R, Sung J, Patel A, Lou XA, Catoiu EA, Palsson BØ, Zielinski DC. A systems-level atlas of carbon-response transcriptional states in Escherichia coli. PNAS. 2026;123(27):e2531884123. doi:10.1073/pnas.2531884123.

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/atlas-carbon-response-transcriptional-states-e-coli

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-07-07.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript sections describing PRECISE-NP881 atlas construction ( ICA/iModulons ), four substrate groups (A–D), CRP decomposition into Crp-1/Crp-2/Crp-3, NtrC-1 and Propionate iModulons linked to propionyl-CoA stress, methylcitrate pathway (prpC/astC), SgcABCEQX prophage iModulon, starvation/refeeding dynam
- transcript topics: ICA-based iModulon analysis; CRP-linked iModulons decomposition (Crp-1, Crp-2, Crp-3); Four substrate groups (A–D) and growth phenotypes; NtrC-1 and Propionate iModulons and propionyl-CoA stress; Methylcitrate pathway and prpC/astC functional evidence; SgcABCEQX prophage iModulon

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- 25 carbon-catabolism iModulons identified (out of 137 total iModulons)
- four activity-defined substrate groups (A–D) with distinct growth and metabolic patterns
- CRP network decomposes into Crp-1, Crp-2, Crp-3 iModulons
- NtrC-1 and Propionate iModulons associated with Group C/D substrates and methylcitrate pathway
- prpC (methylcitrate synthase) deletion reduces growth on Group C/D substrates but not on glucose
- SgcABCEQX prophage iModulon induced under nitrogen-containing, slower-growth conditions; not required for growth in tested conditions

QC result: Pass.

408: Tau, mitochondria, and the fusion switch

Gustavo Barra — Mon, 06 Jul 2026 07:17:02 +0000

Tsakiria E et al., Proceedings of the National Academy of Sciences (PNAS) - Using Tau knockout mice and the C. elegans PTL-1 deletion, this study shows that loss of wild-type Tau promotes a conserved shift toward mitochondrial fusion, increases respiratory activity, membrane potential and mitophagy, raises ROS, and enhances stress resilience. The adaptive phenotypes depend on mitofusin/FZO-1 and are phenocopied by FZO-1 overexpression. Key terms: Tau protein, mitochondrial fusion, mitofusin (FZO-1), mitophagy, neurodegeneration.

Study Highlights:
Across mouse and nematode models, Tau/PTL-1 deficiency increased basal and ATP-linked respiration, mitochondrial membrane potential, and ROS while enhancing mitophagy. Loss of Tau shifted mitochondrial morphology toward a pro-fusion state with increased mitofusin (Mfn1/2/FZO-1) localization and reduced Drp1 recruitment. Genetic removal of the mitofusin FZO-1 abolished the enhanced bioenergetics, motility, longevity under stress, and stress resistance, whereas FZO-1 overexpression phenocopied key Tau-loss features. These results identify a conserved, mitofusin-dependent mechanism by which wild-type Tau restrains mitochondrial fusion and functional adaptation.

Conclusion:
Wild-type Tau acts as a conserved negative regulator of mitochondrial fusion and functional adaptation; its loss triggers FZO-1/mitofusin-dependent mitochondrial remodeling that elevates bioenergetics and stress resilience in a context-dependent manner.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Tau protein as a regulator of mitochondrial function and dynamics

First author:
Tsakiria E

Journal:
Proceedings of the National Academy of Sciences (PNAS)

DOI:
10.1073/pnas.2521642123

Reference:
Tsakiria E., Campos-Marques C., Ferreira I.L., Trougakos I.P., Dioli C., Gianniou D.D., Silva J.M., Skourti K., Roussos A., Samiotaki M., Sotiropoulos I., Palikaras K., et al. Tau protein as a regulator of mitochondrial function and dynamics. Proc Natl Acad Sci U S A. 2026; doi:10.1073/pnas.2521642123.

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/tau-mitochondrial-fusion-episode-408

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-07-06.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Substantively audited sections covering: WT Tau localization and baseline role; Tau/PTL-1 deficiency effects on respiration and mitophagy; pro-fusion shift and changes in fission/fusion proteins; ROS dynamics and hormetic effects; dependency on FZO-1 and rescue via FZO-1 overexpression; implications for Tau-lowering th
- transcript topics: Tau deficiency and mitochondrial respiration (Seahorse data in Tau-KO mice and PTL-1 KO worms); Mitochondrial morphology and fusion/fission regulators (DRP-1, MFN1/MFN2, form factor); Mitophagy dynamics in Tau/PTL-1 deficiency; ROS production and membrane potential changes; ROS-mediated hormesis and antioxidant effects (NAC) across conditions; Genetic dissection: role of FZO-1 (fusion) and DRP-1 (fission)

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 5
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Tau deficiency increases mitochondrial respiration (basal and ADP-stimulated OCR) in Tau-KO mice and PTL-1 KO C. elegans neurons
- Loss of Tau/PTL-1 promotes pro-fusion mitochondrial state with decreased DRP-1 at mitochondria and increased MFN1/MFN2
- Mitophagy is enhanced in Tau-KO and PTL-1 KO models
- Mitochondrial membrane potential increases and ROS production rises with Tau deficiency
- Under mild stress, Tau/PTL-1-deficient animals show improved survival; antioxidant NAC modulates lifespan depending on temperature/condition
- Fusion is required for Tau/PTL-1–deficiency–mediated benefits; FZO-1 loss suppresses phenotypes; FZO-1 overexpression phenocopies Tau loss

QC result: Pass.

407: SLC11A2 withholds metals from Salmonella in the gut epithelium

Gustavo Barra — Sun, 05 Jul 2026 09:46:12 +0000

Norberg ES et al., Proceedings of the National Academy of Sciences - Using metal‑responsive fluorescent Salmonella reporters, calf intestinal loops, and CRISPR edited epithelial cells, this study shows that the divalent metal transporter SLC11A2 is recruited to Salmonella‑containing vacuoles and restricts Fe2+ and Mn2+, limiting intracellular bacterial replication. Key terms: SLC11A2, nutritional immunity, Salmonella enterica, iron and manganese, intestinal epithelium.

Study Highlights:
The authors used metal‑sensing GFP reporters in Salmonella and a calf ligated ileal loop model to map metal availability and found a subpopulation of bacteria in IECs and lamina propria cells exposed to ≤0.1 µM Fe2+ and Zn2+, and possibly Mn2+, early in infection. SLC11A2 localized to the apical surface and endosomal network of IECs and was recruited to maturing Salmonella‑containing vacuoles; CRISPR knockout of SLC11A2 in HCT116 epithelial cells increased bacterial replication. Fluorescent reporters and ICP‑MS indicate vacuolar STm are less starved for Fe2+ and Mn2+ in the absence of SLC11A2, while Zn2+ and Mg2+ sensing was unchanged. Salmonella counters SLC11A2‑mediated restriction through the Mn2+/Fe2+ transporter MntH and siderophore production.

Conclusion:
SLC11A2 mediates epithelial nutritional immunity by sequestering Fe2+ and Mn2+ in Salmonella‑containing vacuoles, reducing vacuolar metal availability and limiting intracellular Salmonella replication.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
SLC11A2 withholds divalent metals from
Salmonella
in the gut epithelium

First author:
Norberg ES

Journal:
Proceedings of the National Academy of Sciences

DOI:
10.1073/pnas.2532675123

Reference:
Norberg ES, Knodler LA, et al. SLC11A2 withholds divalent metals from Salmonella in the gut epithelium. PNAS. 2026;123:e2532675123. doi:10.1073/pnas.2532675123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/slc11a2-withholds-divalent-metals-from-salmonella

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-07-05.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited transcript sections covering nutritional immunity concepts, IEC-localized SLC11A2 function, calf ileal loop in vivo model, metal-responsive STm reporters, SLC11A2 recruitment to SCVs, SLC11A2 knockout effects in HCT116 cells, bacterial countermeasures (MntH and siderophores), intracellular niches (SCV vs cytoso
- transcript topics: Nutritional immunity and trace metal tug-of-war; SLC11A2 (NRAMP2) in intestinal epithelial cells; Calf ligated ileal loop model and metal availability; Metal-responsive Salmonella reporters (iroN, sitA, zinT); SLC11A2 recruitment to Salmonella-containing vacuoles; SLC11A2 knockout in HCT116 cells and impact on Salmonella replication

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- SLC11A2 is recruited to Salmonella-containing vacuoles (SCV) in intestinal epithelial cells and restricts Fe2+ and Mn2+ availability within SCVs, limiting intracellular Salmonella
- Deletion of SLC11A2 in HCT116 cells increases Salmonella replication intracellularly, notably at 8 and 16 hours post-infection in 1% fetal calf serum conditions.
- Salmonella counteracts SLC11A2 through MntH and siderophores; entC deletion reduces replication in WT and complementation rescues replication, indicating competition for Fe2+/Mn2+
- Metal-reporter data show early metal starvation in a subpopulation of intracellular Salmonella (≈38% Zn2+-limited at 2 h; regional shifts by 8 h toward lamina propria).
- Calf ligated ileal loop model demonstrates metal restriction at IECs and lamina propria during acute infection.
- SLC11A2 knockout reduces ferritin (FTH1/FTL) levels in cells, suggesting reduced cytosolic iron availability.

QC result: Pass.

406: Temperature & Age Shape Gut Susceptibility to HCoV-229E

Gustavo Barra — Wed, 01 Jul 2026 18:28:23 +0000

Synowiec A et al., Proceedings of the National Academy of Sciences (PNAS) - This episode examines a PNAS study using fetal, pediatric, and adult human intestinal enteroids to show that physiological temperature and developmental stage jointly determine susceptibility to HCoV-229E, with implications for extrapulmonary coronavirus infection and therapeutic testing. Key terms: HCoV-229E, intestinal enteroids, temperature sensitivity, age-dependent susceptibility, ANPEP/TMPRSS2.

Study Highlights:
The authors used age-stratified human intestinal enteroids (HIEs) and compared infection at 32 °C and 37 °C, finding temperature-dependent transcriptional reprogramming. HCoV-229E productively infected HIEs from all ages at 32 °C, but at 37 °C replication was largely restricted to fetal and some pediatric tissues. Enterocytes were identified as the primary target cells and viral progeny were released apically. Inhibition of serine proteases with camostat significantly reduced HCoV-229E replication, supporting a TMPRSS2-like entry dependency.

Conclusion:
Physiological temperature and developmental maturity create a dual barrier that limits intestinal replication of HCoV-229E in adults at 37 °C while permitting broader replication at cooler, upper-airway-like temperatures; HIEs provide a platform to probe host determinants and test entry-directed inhibitors such as camostat.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Temperature and developmental stage govern intestinal susceptibility to human coronavirus 229E

First author:
Synowiec A

Journal:
Proceedings of the National Academy of Sciences (PNAS)

DOI:
10.1073/pnas.2600632123

Reference:
Synowiec A., Lie L.K., Szczepański A., et al. Temperature and developmental stage govern intestinal susceptibility to human coronavirus 229E. Proc. Natl. Acad. Sci. U.S.A. 2026;123(26):e2600632123. https://doi.org/10.1073/pnas.2600632123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/temp-age-hcov-229e-ep406

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-07-01.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the portions of the transcript describing: experimental design (age-stratified HIEs at 32°C vs 37°C), replication patterns of HCoV-229E (32°C broad permissivity; 37°C restricted), cell tropism (enterocytes as primary target), entry mechanism (ANPEP receptor, TMPRSS2 proteases), and protease inhibition (camostat
- transcript topics: HCoV-229E infection in age-stratified human intestinal enteroids (HIEs); Temperature effects (32 °C vs 37 °C) on replication; Age dependence and donor variability; Cell type tropism and ANPEP/TMPRSS2 entry; Camostat inhibition and entry pathways; Limitations of the HIE model and translational implications

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 4
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Three age groups of HIEs used: fetal, pediatric, adult
- Seasonal HCoVs tested; primary focus on HCoV-229E
- 32 °C supports robust replication of HCoV-229E across all donor ages with apical release
- 37 °C largely restricts replication to fetal and some pediatric tissues; adults show resistance
- Enterocytes identified as main target cells for HCoV-229E
- Camostat markedly reduces HCoV-229E replication; serine protease dependence demonstrated

QC result: Pass.

405: PRDM9 and the Hotspot Trade-off

Gustavo Barra — Wed, 01 Jul 2026 07:39:46 +0000

Úbeda F et al., Proceedings of the National Academy of Sciences (PNAS) - A population-genetic model explains why sequence-specific PRDM9-guided recombination hotspots can evolve and persist alongside non-PRDM9 hotspots by trading off reduced overall binding for increased symmetric binding that more often yields crossovers. Key terms: PRDM9, recombination hotspots, biased gene conversion, symmetric binding, population genetics.

Study Highlights:
The authors develop a three-locus population genetic model and run analytical and numerical simulations to compare PRDM9-like (specific) versus non-PRDM9 (unspecific) hotspot mechanisms. They find non-PRDM9 hotspots are generally favored because they yield higher overall binding and more crossovers, but PRDM9 can be favored when symmetric binding more often resolves as crossovers. Intermediate parameter regimes permit stable coexistence or cyclical oscillations in the relative use of both hotspot types. The model makes testable predictions linking chromosome architecture and fertility costs to the evolutionary distribution of hotspot mechanisms.

Conclusion:
PRDM9 persistence reflects a trade-off: sequence specificity reduces average binding but increases symmetric homolog binding that can disproportionately raise crossover success; when the crossover-resolution advantage of symmetric binding outweighs binding loss, PRDM9 is favored or can coexist with non-PRDM9 mechanisms.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
On the origin of PRDM9-guided recombination hotspots

First author:
Úbeda F

Journal:
Proceedings of the National Academy of Sciences (PNAS)

DOI:
10.1073/pnas.2535682123

Reference:
Úbeda F, Bürger R, Fyon F. On the origin of PRDM9-guided recombination hotspots. Proc Natl Acad Sci U S A. 2026;123(26):e2535682123. doi:10.1073/pnas.2535682123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/405-prdm9-hotspots

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-07-01.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript portions describing hotspot mechanisms, symmetric vs asymmetric binding, the three-locus model (modifier M, targeting A, target B), key results (dominance of non-PRDM9, potential PRDM9 advantage with symmetric binding, coexistence and oscillations), phylogenetic patterns and chromosome-size impli
- transcript topics: PRDM9-guided recombination vs non-PRDM9 hotspots; Symmetric vs asymmetric binding in recombination; Three-locus population-genetic model (modifier, targeting, target loci); Evolutionary outcomes: dominance, coexistence, oscillations; Phylogenetic distribution and chromosome-size effects

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 4
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Two hotspot mechanisms exist: PRDM9-guided (specific) and non-PRDM9 (open chromatin, sequence-independent).
- PRDM9 hotspots erode via biased gene conversion; non-PRDM9 hotspots are self-preserving.
- Symmetric binding increases crossovers; asymmetric binding reduces crossover probability.
- Model uses three loci: modifier M, targeting A, and target B; binding outcomes include symmetric, asymmetric, or none.
- When symmetric and asymmetric bindings are equally likely to resolve as crossovers, non-PRDM9 is the evolutionarily stable state.
- If symmetric binding has a crossover-resolution advantage (ρs > ρa), PRDM9 can be favored or coexist with non-PRDM9.

QC result: Pass.

404: RUNA Reveals Surface DNA on Exosomes

Gustavo Barra — Tue, 30 Jun 2026 19:06:18 +0000

Bošković F et al., Proceedings of the National Academy of Sciences - This study introduces RUNA, a reversible chemistry that selectively labels uridine/thymidine to map nucleic acids across membranes, and uses it to show that most exosomal DNA is surface-exposed, increases after PARP inhibitor treatment, and alters macrophage uptake and activation. Key terms: RUNA, exosomes, surface DNA, macrophage polarization, PARP inhibitor.

Study Highlights:
The authors developed Reversible Uridine Nitrilium-mediated Addition (RUNA), which selectively and reversibly modifies the N3 of uridine and thymidine via an in situ nitrilium ion. By varying aldehyde membrane permeability, RUNA distinguishes intra-vesicular from extravesicular nucleic acids. Applied to exosomes from MyC-CaP prostate cancer cells, RUNA shows most exosomal DNA is surface-exposed and nearly doubles after rucaparib (PARP inhibitor) treatment. Surface DNA promotes uptake by M2 macrophages through scavenger receptors and shifts them toward an M1-like proinflammatory profile.

Conclusion:
RUNA is a modular, reversible chemical tool to map nucleic acid accessibility across membranes; using it the authors reveal exosomal surface DNA as a dynamic, damage-responsive determinant of macrophage uptake and immune modulation with implications for tumor–immune interactions.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
A nucleic acid labeling chemistry reveals surface DNA on exosomes

First author:
Bošković F

Journal:
Proceedings of the National Academy of Sciences

DOI:
10.1073/pnas.2532281123

Reference:
Bošković F, Dutta Gupta P, Zhang J, Szostak JW, Krishnan Y. A nucleic acid labeling chemistry reveals surface DNA on exosomes. Proc Natl Acad Sci U S A. 2026;123(27):e2532281123. doi:10.1073/pnas.2532281123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/runa-surface-dna-on-exosomes

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-06-30.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited sections describing RUNA mechanism, membrane-permeability tuning, exosome surface DNA, PARP-inhibitor effects on surface DNA, exosome uptake by M2 macrophages, macrophage polarization to an M1-like state, and study limitations.
- transcript topics: RUNA mechanism and reversibility; Membrane permeability tuning to distinguish exRNA vs vesicular RNA; Exosome DNA topology: surface-exposed vs luminal; PARP inhibitor (rucaparib) effects on surface DNA; Exosome uptake by M2 macrophages via scavenger receptors; Macrophage polarization to M1-like state and cytokine changes

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- RUNA selectively labels uridine and thymidine at N3 to form a reversible covalent adduct.
- The RUNA adduct is thermally reversible by heating (e.g., 95 C for 15 minutes).
- Membrane-permeable vs membrane-impermeable aldehydes distinguish total vs extravesicular nucleic acids.
- Exosomes carry DNA on their outer surface; surface DNA abundance increases with PARP inhibitor treatment.
- Surface DNA drives uptake of exosomes by M2 macrophages via scavenger receptors.
- Uptake of surface-DNA–bearing exosomes shifts macrophages toward an M1-like pro-inflammatory state (IL-12, TNF-α, iNOS, CCL2 up; arginase-1 down).

QC result: Pass.

403: HRD-GIS Evidence for BRCA1/2 Variant Classification

Gustavo Barra — Fri, 26 Jun 2026 08:11:59 +0000

Schnaiter et al et al., The American Journal of Human Genetics - Schnaiter et al. pooled Myriad MyChoice HRD+ CDx results from four cohorts (4,943 HGOC tumors) to test whether tumor HRD-related genomic instability scores (HRD-GIS) provide evidence for BRCA1 and BRCA2 variant classification under ACMG/AMP criteria. Key terms: homologous recombination deficiency, genomic instability score (HRD-GIS), BRCA1, BRCA2, MyChoice HRD+ CDx.

Study Highlights:
The authors analyzed 4,943 tumors (765 BRCApv, 4,178 BRCAwt) assessed with the MyChoice HRD+ CDx assay and found 91.0% of BRCApv tumors were GIShigh (≥42) versus 30.0% of BRCAwt. The pooled likelihood ratio (LR) that a variant is pathogenic in a GIShigh HGOC was 3.03 (95% CI: 2.88–3.19), mapping to supporting pathogenic evidence. Conversely, the pooled LR for GISlow (<42) was 0.13 (95% CI: 0.10–0.16), mapping to moderate benign evidence. Results were consistent across three cohorts but limited by assay type, cohort composition, and incomplete second-hit and germline/somatic data.

Conclusion:
HRD-GIS measured by the MyChoice HRD+ CDx assay in HGOC yields statistically robust evidence that can be applied within ACMG/AMP variant interpretation: GIShigh supports pathogenicity (supporting strength) and GISlow supports benign classification (moderate strength), potentially improving BRCA1/2 VUS resolution.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Homologous recombination deficiency-driven genomic instability in ovarian cancer as an indicator of BRCA1 and BRCA2 variant pathogenicity

First author:
Schnaiter et al

Journal:
The American Journal of Human Genetics

DOI:
10.1016/j.ajhg.2026.05.015

Reference:
Schnaiter et al., 2026, The American Journal of Human Genetics 113, 1–8. https://doi.org/10.1016/j.ajhg.2026.05.015

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/hrd-gis-brca-variant-pathogenicity

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-06-26.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript's coverage of HRD-GIS mechanism, BRCA1/BRCA2 variant interpretation via ACMG/AMP LR framework, threshold 42 (GIShigh vs GISlow), cohort data (Marburg, NHS, Study 19, NOVA), the Myriad MyChoice HRD+ CDx assay, and discussed limitations (second hits, germline vs somatic, assay-specific validation).
- transcript topics: HRD-GIS mechanism in HGOC; BRCA1/BRCA2 function and HRD; Genomic scar metrics: LOH, TAI, LST; GIS scoring threshold and GIShigh/GISlow; Likelihood ratio framework and ACMG/AMP evidence mapping; Cohort data and Myriad MyChoice HRD+ CDx validation

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- HRD-GIS is a composite of LOH, telomeric allelic imbalance (TAI), and large-scale state transitions (LST).
- GIS high is GIS ≥ 42; GIS low is GIS < 42.
- Dataset comprised 4,943 HGOC tumors (765 BRCApv, 4,178 BRCAwt).
- Among BRCApv, 91.0% were GIShigh; among BRCAwt, 30.0% were GIShigh.
- LR for BRCA1/BRCA2 variant pathogenicity in GIShigh HGOC: 3.03 (95% CI 2.88–3.19) → supporting pathogenic evidence.
- LR for BRCA1/BRCA2 variant pathogenicity in GISlow HGOC: 0.13 (95% CI 0.10–0.16) → moderate benign evidence.

QC result: Pass.

402: When Polygenic Scores Miss: Rare Variants in Misaligned Individuals

Gustavo Barra — Thu, 25 Jun 2026 20:34:18 +0000

Baya N et al., The American Journal of Human Genetics 113, 1–19 (2026) - Baya et al. applied a misalignment framework to UK Biobank polygenic scores and exomes and found that individuals whose observed phenotypes deviate from polygenic expectation are enriched for rare damaging variants across multiple traits and diseases. Key terms: polygenic scores, rare variants, misalignment, liability threshold, UK Biobank.

Study Highlights:
The authors define 'misaligned' individuals whose covariate-residualized phenotypes differ markedly from PGS expectation and test enrichment for rare (MAF <0.1%) pLoF and damaging missense variants. In UK Biobank Europeans they replicate enrichments for canonical genes (e.g., ACAN, IGF1, APOB, LDLR) and identify novel exome-wide associations including COPB2, GORAB, KANK1, and ACSL6. Disease analyses support a liability-threshold model: T2D cases with HNF1A/HNF4A pLoFs had lower PRS, and CAD controls with protective ANGPTL3 variants had higher PRS. Misalignment classification helps prioritize individuals for rare-variant screening and can reveal pathogenic or protective genetic contributors.

Conclusion:
Deviation from polygenic expectation highlights individuals enriched for rare damaging variants, supporting a liability-threshold model where rare and common variants counteract or augment each other and offering a strategy to prioritize rare-disease genetic discovery.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Individuals who deviate from polygenic expectation are enriched for damaging variants in genes linked to rare disease

First author:
Baya N

Journal:
The American Journal of Human Genetics 113, 1–19 (2026)

DOI:
10.1016/j.ajhg.2026.05.013

Reference:
Baya N.A., Lassen F.H., Hill B., Venkatesh S.S., Currant H., Lindgren C.M., Palmer D.S., Individuals who deviate from polygenic expectation are enriched for damaging variants in genes linked to rare disease, The American Journal of Human Genetics 113, 1–19 (2026). doi:10.1016/j.ajhg.2026.05.013

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/polygenic-misalignment-rare-variants

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-06-25.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript sections describing the misalignment framework, continuous-trait enrichments (height-related ACAN/IGF1, FBN1 for tall stature, LDL-C genes), BMD findings (COPB2/GORAB), LDL-C/HDL gene burdens (LDLR/APOB/PCSK9), dichotomous-trait results (T2D with HNF1A/HNF4A, CAD ANGPTL3), exome-wide discovery (7
- transcript topics: Phenotypic misalignment framework and liability-threshold model; Continuous-trait misalignment analyses (height, LDL-C, BMI, BMD, HbA1c, IOP, age at menopause); Canonical gene enrichment for height and LDL-C (ACAN, IGF1, SHOX; LDLR, APOB, PCSK9); Damaging variant enrichment in FBN1 for height misalignment (taller-than-expected); Exome-wide discovery of misalignment genes (KANK1, ACSL6, NPL, COPB2, GORAB); Dichotomous-trait misalignment (T2D/HNF1A/HNF4A; CAD/ANGPTL3; OP)

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Misaligned individuals enriched for rare damaging variants in canonical genes for height/LDL-C (ACAN, IGF1; FBN1 for tall stature; LDLR/APOB/PCSK9 for LDL-C effects).
- Higher-than-expected vs lower-than-expected stature linked to pLoF in ACAN/IGF1 and damaging missense in FBN1, respectively.
- Dichotomous traits (T2D, CAD, OP) show enrichment patterns: T2D cases with low PRS enriched for pathogenic pLoF in HNF1A/HNF4A; CAD controls with protective ANGPTL3 pLoF enriched f
- Exome-wide scan identified 74 significant genes; KANK1 and ACSL6 highlighted among BMI-related findings; NPL linked to BMI; KANK1 linked to AAM.
- BMI lower-than-expected misalignment associated with NPL and ACSL6; AAM higher-than-expected associated with KANK1.
- Non-genetic factors (SES, cholesterol-lowering medication, smoking, exercise) correlate with misalignment; population ancestry limitation noted (European only).

QC result: Pass.

401: LDB1 variants split neurodevelopmental outcomes by location and mechanism

Gustavo Barra — Tue, 23 Jun 2026 09:35:42 +0000

Fluri R et al., The American Journal of Human Genetics - This episode examines a cohort study of 16 individuals with de novo LDB1 variants that reveals two overlapping but distinct neurodevelopmental phenotypes tied to variant location. Functional assays and Drosophila models demonstrate loss-of-function effects for N-terminal variants and dominant-negative effects for C-terminal variants. Key terms: LDB1, neurodevelopmental disorder, ventriculomegaly, dominant-negative, haploinsufficiency.

Study Highlights:
The authors assembled 16 individuals with de novo LDB1 variants and mapped variants to the N-terminal dimerization domain or the C-terminal LIM interaction domain. In vitro assays showed N-terminal missense variants disrupt homodimerization leading to loss of function, while C-terminal variants impair LHX2 binding and act in a dominant-negative manner. Drosophila knockdown and overexpression corroborated dosage sensitivity and distinct in vivo effects, including rescue by wild-type LDB1 and worsening by C-terminal variants. Clinically, C-terminal LID-affecting variants associate with congenital ventriculomegaly and more frequent extra‑neural anomalies, whereas N-terminal variants tend to cause variable NDD without consistent brain malformations.

Conclusion:
Variant location in LDB1 predicts distinct pathomechanisms and overlapping clinical presentations: N-terminal variants cause haploinsufficiency/loss of function, while C-terminal LID variants act dominant-negatively and are linked to ventriculomegaly and broader organ involvement.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
De novo variants in LDB1 are linked to distinct neurodevelopmental phenotypes determined by variant location and differing pathomechanisms

First author:
Fluri R

Journal:
The American Journal of Human Genetics

DOI:
10.1016/j.ajhg.2026.05.012

Reference:
Fluri R., Coll-Tané M., Brunet T., et al. De novo variants in LDB1 are linked to distinct neurodevelopmental phenotypes determined by variant location and differing pathomechanisms. The American Journal of Human Genetics. 2026;113:1–15. doi:10.1016/j.ajhg.2026.05.012

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/ldb1-variant-location-pathomechanisms

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-06-23.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited sections describing LDB1 structure (DD and LID), variant spectrum (N-terminal vs C-terminal), two mechanisms (haploinsufficiency vs dominant-negative), cellular assays (protein levels, ubiquitination, aggregates), LDB1-LHX2 interactions, Drosophila chi model (dosage sensitivity, rescue/toxicity, sleep), and cli
- transcript topics: LDB1 structure and domains (DD and LID); Variant spectrum across LDB1 (N-terminal vs C-terminal); Mechanisms: haploinsufficiency and dominant-negative effects; Cellular assays: protein stability, ubiquitination, aggregates; LDB1 interactions: dimerization and LHX2 binding; Drosophila model chi (chip) dosage sensitivity and experiments

QC Summary:
- factual score: 9/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 1
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Two distinct LDB1-related neurodevelopmental phenotypes based on variant location (N-terminal LoF/haploinsufficiency vs C-terminal dominant-negative)
- N-terminal DD missense variants Arg121Trp and Arg193Trp impair LDB1 homodimerization (loss of function)
- C-terminal LID-disrupting variants impair LDB1-LHX2 interaction and act in a dominant-negative manner
- C-terminal frameshift variants increase LDB1 protein levels and form nuclear aggregates via altered ubiquitination
- N-terminal DD variants can decrease protein stability in some contexts
- Co-expression assays show dominant-negative interference of C-terminal variants with wild-type LDB1/LHX2 interactions

QC Flagged Items (audited and not fully supported):
- Core claim uncertain: The Arg181Gln variant remains a VUS with uncertain functional effect.

QC result: Warning. Items above were flagged during automated QC; the editorial team reviewed them before release.

400: Complete chromosome 21 centromere sequencing and Down syndrome

Gustavo Barra — Tue, 23 Jun 2026 06:41:30 +0000

Mastrorosa F et al., The American Journal of Human Genetics - Long-read assemblies and epigenetic mapping of chromosome 21 centromeres in families with trisomy 21 reveal centromere size diversity, two cases of extreme maternal centromere size asymmetry, and no global enrichment of small centromeres in affected individuals. Key terms: trisomy 21, centromere, alpha-satellite, long-read sequencing, meiotic nondisjunction.

Study Highlights:
Using PacBio HiFi and ultra-long ONT reads with hybrid assembly and DiMeLo-seq, the authors fully resolved chr21 centromeres in eight T21 individuals and several parents and compared them to 287 population haplotypes. Small centromeres were not overall enriched in T21 cases, contradicting earlier reports, but two families showed extreme (>10-fold) maternal centromere size asymmetry. CDRs and CENP-A/CENP-C signals were present across haplotypes and methylation profiles were largely conserved between generations and sample types. Phylogenetic analysis indicates recent rapid evolution of chr21 centromere haplotypes that may facilitate such asymmetry.

Conclusion:
Centromere size alone does not explain trisomy 21 risk at the population level, but extreme maternal centromere size asymmetry appears in a minority of families and may contribute to nondisjunction in those cases.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Complete chromosome 21 centromere sequencing of families with Down syndrome

First author:
Mastrorosa F

Journal:
The American Journal of Human Genetics

DOI:
10.1016/j.ajhg.2026.05.010

Reference:
Mastrorosa F.K., Daponte A., de Gennaro L., et al. Complete chromosome 21 centromere sequencing of families with Down syndrome. The American Journal of Human Genetics. 113, 1–18 (2026). https://doi.org/10.1016/j.ajhg.2026.05.010

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/chr21-centromere-sequencing-down-syndrome

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-06-23.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited transcript sections covering centromere structure, long-read sequencing workflow, extreme centromere size asymmetry findings, CpG/epigenetic mapping (CDRs, CENP-A/CENP-C), and population/evolutionary context.
- transcript topics: Centromere structure and alpha-satellite HOR arrays; Maternal nondisjunction and Down syndrome etiology; Long-read sequencing technologies and hybrid phasing; Epigenetic centromere mapping (CDRs, CENP-A/CENP-C, CpG methylation); Centromere size asymmetry in Down syndrome families; Population diversity of chr21 centromeres (African ancestry four-mer HOR)

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Small chr21 centromeres are not enriched in Down syndrome cases compared with controls (p = 0.72).
- Extreme centromere size asymmetry (>10-fold) observed in two Down syndrome families (e.g., 10.7-fold...

Chapters

(00:00:20) - Down Syndrome: The mystery of the cell division
(00:04:45) - Down Syndrome: The repetitive DNA handles
(00:09:49) - Down Syndrome: The tug of war
(00:14:16) - The genetics of trisomy 21
(00:15:58) - Down Syndrome: The mystery of the genetic cause
(00:20:13) - A Single Link in the Code

399: Ménière disease: inner ear development and retinoic acid pathways

Gustavo Barra — Mon, 22 Jun 2026 06:44:44 +0000

Shi Z et al., The American Journal of Human Genetics - A large GWAS meta-analysis across five biobanks (8,969 cases, 1,962,542 controls) identifies five genome-wide significant loci for Ménière disease, implicating developmental regulators EYA1/EYA4 and retinoic acid metabolism genes including CYP26A1. Integrative fine-mapping, eQTL, and single-cell expression place these signals in inner ear cell types and link MD to related sensory and neurological traits. Key terms: Ménière disease, EYA1, EYA4, retinoic acid, GWAS.

Study Highlights:
A GWAS meta-analysis of 8,969 Ménière disease cases and 1,962,542 controls across five biobanks identified five independent genome-wide significant loci, including two signals each at EYA4 and EYA1 and one near CYP26A1. Observed-scale SNP heritability was estimated at 7% (SE 0.8%), indicating a modest contribution of common variation. Fine-mapping, eQTL and single-cell expression data implicate dysregulation of inner ear developmental regulators and retinoic acid metabolism. Phenome-wide and genetic-correlation analyses reveal shared architecture with vertigo, tinnitus, hearing loss, migraine, and sleep apnea.

Conclusion:
Regulatory common variants in genes governing inner ear development (EYA1, EYA4) and retinoic acid signaling (CYP26A1/C1, ALDH1A2) contribute to Ménière disease risk, providing a genetic framework for functional follow-up and polygenic risk modeling.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Genome-wide analysis implicates inner ear development in Ménière disease

First author:
Shi Z

Journal:
The American Journal of Human Genetics

DOI:
10.1016/j.ajhg.2026.05.011

Reference:
Shi Z, Mandla R, Li J, et al. Genome-wide analysis implicates inner ear development in Ménière disease. The American Journal of Human Genetics. 2026;113:1–12. https://doi.org/10.1016/j.ajhg.2026.05.011

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/base-by-base-399-meniere-inner-ear

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-06-22.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Substantive audit of the transcript's representation of GWAS scale, loci and genes (EYA4, EYA1, CYP26A1, ALDH1A2, LMO4), developmental/retinoic acid pathways, genetic correlations, limitations, and future directions as reported in the canonical article.
- transcript topics: Genome-wide association study scale and meta-analysis across five biobanks; Identification of five independent signals: two at EYA4, two at EYA1, one near CYP26A1; EYA4 and EYA1 as developmental regulators of inner ear; Regulatory vs coding variants and gene expression implications; Retinoic acid signaling pathway involvement: CYP26A1/C1 and ALDH1A2; LMO4 as a suggestive signal and its developmental context

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- MD SNP-based heritability estimated at 7% (SE 0.8%) on the observed scale
- Five independent genome-wide significant index SNPs: two at EYA4, two at EYA1, one near CYP26A1
- Two additional loci near LMO4 and ALDH1A2 are suggestive rather than genome-wide significant
- Developmental regulation of inner ear (EYA4/EYA1) and retinoic acid metabolism (CYP26A1/C1, ALDH1A2) as core pathways
- Genetic correlations between MD and vertigo, tinnitus, hearing loss, migraine, sleep apnea; additional overlap with glaucoma
- Functional follow-up suggested via human inner ear organoids and polygenic risk modeling

QC result: Pass.

398: Modeling JAK2V617F Clonal Expansion in the General Population

Gustavo Barra — Sun, 21 Jun 2026 22:50:35 +0000

Snyder J et al., Proceedings of the National Academy of Sciences (PNAS) - Longitudinal VAF measurements from 67 JAK2V617F-positive participants in the Danish GESUS study were analyzed with a Moran-process stem cell model and ABC-SMC to infer per-individual self-renewal advantages and assess prognostic value for MPN progression. Key terms: JAK2V617F, clonal hematopoiesis, Moran model, myeloproliferative neoplasms, mathematical modeling.

Study Highlights:
The study follows 67 individuals from the GESUS cohort with >1% JAK2V617F VAF and multiple follow-up measurements over >10 years. A Moran-process model at the HSC level fitted by ABC-SMC reproduced longitudinal VAF trajectories for 66 of 67 subjects and yielded per-individual estimates of the mutant self-renewal advantage s. Results show heterogeneity: ~70% of subjects had a statistically positive s, ~18% had a negative s, and ~12% were neutral, indicating many carriers show no expansion or even contraction. The fitted model can predict future VAF evolution for most subjects but s alone is not a perfect predictor of MPN diagnosis.

Conclusion:
A stem-cell Moran-process model explains longitudinal JAK2V617F VAF dynamics in most GESUS participants; inferred selective advantage varies widely, correlates with—but does not fully predict—MPN diagnosis, supporting individualized monitoring and further study of non-VAF risk factors.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Mathematical modeling of JAK2V617F clonal expansion in a general population cohort

First author:
Snyder J

Journal:
Proceedings of the National Academy of Sciences (PNAS)

DOI:
10.1073/pnas.2507773123

Reference:
Snyder J, Andersen M, Gudmand-Høyer J, et al. Mathematical modeling of JAK2V617F clonal expansion in a general population cohort. Proc Natl Acad Sci U.S.A. 2026;123:e2507773123. doi:10.1073/pnas.2507773123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/base398-jak2v617f-moran

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-06-21.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Substantively audited sections include background on JAK2V617F and MPN, Moran process model with carrying capacity and generation time, ABC-SMC inference of per-subject s, results breakdown (positive/neutral/negative s and 66/67 fit), link between s and MPN progression, inflammation/CRP and statin discussion, and limit
- transcript topics: JAK2V617F mutation and myeloproliferative neoplasms biology; Moran process model and stem cell carrying capacity; Inference of per-individual selective advantage (s) via ABC-SMC; VAF trajectories across individuals and fit to the model; Association between s and progression to MPN; imperfect prediction; Inflammation (CRP) and statins as modifiers of clonal dynamics

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- 67 individuals with >1% JAK2V617F VAF in the GESUS cohort followed longitudinally over ~10 years
- A Moran process with fixed carrying capacity N ≈ 100,000 and generation time Tg ≈ 200 days
- Selective advantage s inferred per subject using ABC-SMC; distribution: ~47/67 positive, ~12/67 negative, ~8/67 neutral
- 66 of 67 subjects' data fall within the central 95% of model trajectories
- 37 of 67 subjects progressed to overt MPN; higher average s associated with progression but not perfectly predictive
- Inflammation (CRP) differences between CH and MPN groups; statins may reduce systemic inflammation and modulate clonal advantage

QC result: Pass.

397: SciPhy: Bayesian phylogenetics for sequential genetic lineage tracing

Gustavo Barra — Sat, 20 Jun 2026 08:49:26 +0000

Seidel et al., Nature Communications - SciPhy is a BEAST2-integrated Bayesian framework that models sequential CRISPR‑based insertion edits to jointly infer time-scaled single-cell lineage trees, editing dynamics, and population growth. The authors validate SciPhy on simulations and apply it to HEK293T monoclonal expansion and murine gastruloid datasets, showing improved tree and branch-length inference relative to UPGMA and enabling phylodynamic estimates of growth. Key terms: Bayesian phylogenetics, lineage tracing, CRISPR, DNA Typewriter, phylodynamics.

Study Highlights:
SciPhy implements a mechanistic model of ordered, irreversible insertions with per-tape clock rates and insertion probabilities and computes the likelihood using a pruning algorithm within BEAST2. Validation on calibrated simulations shows correct posterior coverage and high correlations between true and inferred editing and tree parameters. Application to HEK293T and gastruloid data recovers per-tape edit rates and preferential insert probabilities, infers growth rates including time-varying dynamics in gastruloid development, and yields more accurate topologies and branch lengths than UPGMA. The framework reports uncertainty and enables joint phylodynamic analysis of lineage tracing data.

Conclusion:
A mechanistic, order-aware Bayesian model for sequential genome-editing lineage recorders improves reconstruction of time-calibrated cell lineage trees, quantifies editing biases and clock rates, and enables inference of cell population dynamics from single-cell lineage tracing data.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
SciPhy: A Bayesian phylogenetic framework using sequential genetic lineage tracing data

First author:
Seidel

Journal:
Nature Communications

DOI:
10.1038/s41467-026-73377-6

Reference:
Seidel, S., Zwaans, A., Regalado, S. et al. SciPhy: A Bayesian phylogenetic framework using sequential genetic lineage tracing data. Nat Commun (2026). https://doi.org/10.1038/s41467-026-73377-6

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/sciphy-bayesian-lineage-tracing

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-06-20.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Substantive auditing of the transcript's description of SciPhy's mechanistic model (ordered CRISPR edits), BEAST2 implementation, validation results, HEK293T monoclonal expansion, gastruloid development with CHIR treatment, and discussed limitations and computational considerations.
- transcript topics: Mechanistic editing model with ordered inserts; BEAST2 integration and likelihood calculation; Editing rate clock rates and insertion probabilities; Validation: in-silico, HEK293T monoclonal expansion; Insertion bias: CAT vs GCG; Growth dynamics and phylodynamic inference

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- SciPhy is a Bayesian framework implemented in BEAST 2 for jointly estimating time-scaled phylogenies and cell population parameters using sequential, ordered CRISPR edits (DNA Tape
- The model uses per-tape clock rates and insertion probabilities to describe editing dynamics.
- Felsenstein pruning is used for likelihood calculation across the phylogeny with tape data.
- HEK293T monoclonal expansion dataset (~25 days) used to validate editing dynamics and growth rates; observed CAT insertions around 16% and GCG around ≤1%.
- Clock rates around 0.15 d^-1 on most tapes, equating to roughly 4 edits per tape over the experiment duration.
- SciPhy produced more accurate time-calibrated trees and differentiated branch lengths compared to UPGMA on both simulated and real data.

QC result: Pass.

396: Physical homology recognition between DNA duplexes

Gustavo Barra — Thu, 18 Jun 2026 18:47:42 +0000

Stannard A et al., Proceedings of the National Academy of Sciences (PNAS) - This episode summarizes a PNAS study that uses a FRET-responsive DNA tweezers nanosensor to detect and quantify sequence-dependent interactions between intact double-stranded DNA duplexes in ionic solutions. Key terms: homologous recognition, double-stranded DNA, electrostatic interactions, DNA nanosensor, divalent cations.

Study Highlights:
Using a tuned DNA-tweezers FRET assay, the authors show that homologous dsDNA duplexes coalign more readily than heterologous ones in the presence of divalent cations. They quantify a homologous recognition free energy of roughly −0.02 kBT (≈ −0.01 kcal/mol) per base pair and show this is largely independent of Mg2+ versus Ca2+ within the tested range. Controls exclude strand exchange and sequence-specific ion adsorption as alternative explanations. An electrostatic helical coherence model reproduces the magnitude and salt dependence of the measured effect.

Conclusion:
Protein-free, sequence-specific electrostatic interactions between intact dsDNA can produce a small but measurable homology recognition energy consistent with helical coherence theory and relevant under confined, DNA-rich conditions.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Direct evidence and quantiﬁcation of homologous recognition between DNA duplexes

First author:
Stannard A

Journal:
Proceedings of the National Academy of Sciences (PNAS)

DOI:
10.1073/pnas.2530949123

Reference:
Stannard A., Haimov E., Hedley J.G., et al. Direct evidence and quantification of homologous recognition between DNA duplexes. Proc. Natl. Acad. Sci. U.S.A. 2026; doi:10.1073/pnas.2530949123.

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/homologous-dna-recognition-396

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-06-18.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript portions describing the DNA tweezers design and readout, cation dependence, homologous vs heterologous comparison, longer-duplex effects, strand-exchange controls, helical-coherence theory, and cellular relevance.
- transcript topics: DNA tweezers design and FRET readout; Monovalent vs divalent cation effects on duplex coalignment; Homologous versus heterologous sequence comparisons; Strand-exchange controls and GC clamps; Length dependence: 36 bp vs 68 bp and entropic effects; Helical coherence theory mechanism and charge patterning

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Direct evidence for homologous recognition between intact dsDNA in protein-free ionic conditions.
- Recognition energy per base pair is about -0.02 kBT (≈ -0.01 kcal/mol per base pair).
- Recognition is largely independent of whether Mg2+ or Ca2+ is the divalent cation and of their concentration within tested range.
- Divalent cations promote coalignment; onset at ~10 mM (homologous tweezers) vs ~20 mM (heterologous).
- Interaxial separation and adsorption parameters: R ≈ 27.7–27.9 Å; f2 ≈ 0.991–0.999, indicating dominant major-groove adsorption.
- Longer duplexes (68 bp) coalign less due to entropic penalties and increased conformational space.

QC result: Pass.

395: Extended sequence context shapes mutational bias in Escherichia coli

Gustavo Barra — Thu, 18 Jun 2026 18:47:34 +0000

Green R et al., PNAS - Collating >100,000 base-pair substitutions from 32 mutation-accumulation experiments, this study shows that sequence context well beyond adjacent bases — up to ±6 bp and even hundreds of bp — shapes mutational biases in E. coli and interacts with DNA repair. Key terms: mutational bias, sequence context, Escherichia coli, mismatch repair, mononucleotide runs.

Study Highlights:
The authors analyzed 117,807 base-pair substitutions from 32 MA experiments and quantified nucleotide frequencies up to ±6 bp (and sliding windows to 1,000 bp) around mutation sites. Extended context effects vary by substitution type, DNA repair background (proofreading and MMR), and replication strand. Mononucleotide runs (notably AC3+ and GC3+) are strong hotspots consistent with transient misalignment; GC3+ can increase G:C→C:G transversions by orders of magnitude. Broader GC% biases persist hundreds of base pairs and are modulated by MMR activity.

Conclusion:
Extended sequence context and its interaction with proofreading, mismatch repair, and replication strand identity create complex, BPS-specific mutational signatures in E. coli, improving the resolution of mutation-rate predictions and highlighting long-range and motif-specific hotspots.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Extended sequence context shapes mutational bias in Escherichia coli

First author:
Green R

Journal:
PNAS

DOI:
10.1073/pnas.2601345123

Reference:
Green R., Jago M.J., Knight C.G., Czernuszka M.R., Denisova S., Krašovec R., Lagator M. Extended sequence context shapes mutational bias in Escherichia coli. PNAS. 2026;123(23):e2601345123. doi:10.1073/pnas.2601345123.

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/extended-sequence-context-mutational-bias-e-coli

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-06-18.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited sections covering extended sequence context (±6 bp), mononucleotide run hotspots (AC3+, GC3+), GC3+ and G:C→C:G transversions, 5′ preceding nucleotide effects, leading vs lagging strand replication, and GC-content effects up to 1000 bp.
- transcript topics: Extended sequence context (±6 bp); Mononucleotide runs and transient misalignment; GC3+ hotspot and other motifs; DNA proofreading and mismatch repair effects; Leading vs lagging strand replication and context biases; Regional GC-content effects up to 1000 bp

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Extended context up to ±6 bp influences mutational bias beyond trinucleotide context
- Mononucleotide runs AC3+ and GC3+ are mutational hotspots; GC3+ increases G:C→C:G transversions up to ~10^4-fold
- A strong GC3+ hotspot near GG sequences can reach extremely large fold increases; in some backgrounds ~50,000-fold for G:C→C:G transversions at GG C7
- 5′ preceding nucleotide biases modulate GC3+ hotspot strength
- Leading vs lagging strand replication affects context biases; biases stronger when purine templates the leading strand
- Regional GC-content up to 1,000 bp away contributes to mutational bias; AT-rich regions show differential effects depending on repair status (MMR/proofreading)

QC result: Pass.

394: Benchmarking LLMs for cfRNA biomarker discovery

Gustavo Barra — Wed, 17 Jun 2026 11:28:04 +0000

Gaudio HA et al., Nature Communications - This episode examines a systematic benchmark of six commercial large language models applied to plasma cell-free RNA across three clinical cohorts, assessing LLM-driven gene-panel nomination and autonomous classifier construction versus conventional statistical workflows. Key terms: large language models, cell-free RNA, biomarker discovery, machine learning, diagnostics.

Study Highlights:
Six state-of-the-art LLMs were tested on cfRNA datasets from Kawasaki disease vs MIS-C, tuberculosis vs symptomatic controls, and ME/CFS vs sedentary controls for gene-panel nomination and end-to-end classifier building. LLM-nominated panels recapitulated canonical immune pathways and outperformed random gene sets, matching differential expression–derived panels in the tuberculosis cohort. End-to-end automation was feasible but model- and task-dependent: OpenAI o3 matched conventional performance for KD vs MIS-C but underperformed for TB and ME/CFS. Models showed prompt-adherence issues and sometimes returned non-reference or hallucinated features, which limits reproducibility.

Conclusion:
Current LLMs can extract biologically meaningful cfRNA candidate panels and partially automate biomarker workflows, but results are variable and traditional or hybrid statistical workflows remain necessary; rigorous validation and constrained output schemas are required before clinical deployment.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Benchmarking large language models for cell-free RNA diagnostic biomarker discovery

First author:
Gaudio HA

Journal:
Nature Communications

DOI:
10.1038/s41467-026-74077-x

Reference:
Gaudio HA, Bliss A, Loy CJ, Eweis‑LaBolle D, Gardella AE & De Vlaminck I. Benchmarking large language models for cell-free RNA diagnostic biomarker discovery. Nature Communications (2026). doi:10.1038/s41467-026-74077-x

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/benchmarking-llms-cfrna

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-06-17.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Substantively audited the transcript's coverage of the study design, LLM benchmarking across three cohorts, gene-panel nomination, end-to-end classifier construction, prompt effects, and the hybrid-workflow conclusions, with reference to supporting results in the article.
- transcript topics: Study design and cohorts (KD vs MIS-C, TB vs symptomatic controls, ME/CFS vs sedentary controls); Prompt adherence and gene-panel nomination; Comparison of LLM panels to random and DGE panels; End-to-end classifier construction and cross-cohort performance; Disease-informed vs disease-naïve prompts impact; Limitations: probability calibration, data leakage concerns

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 5
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Six LLMs were evaluated across three cohorts: OpenAI o3, GPT-4o, Claude Opus 4, Claude 3.7 Sonnet, Gemini 2.5 Pro, Gemini 2.0 Flash
- Cohorts studied: Kawasaki disease (KD) vs MIS-C, active tuberculosis (TB) vs symptomatic controls, ME/CFS vs sedentary controls
- Two tasks were used: (1) feature selection to nominate 200 genes; (2) end-to-end classifier construction from cfRNA count matrices
- LLM-nominated panels outperformed random panels; TB panels matched/exceeded DGE; KD and ME/CFS panels trailed DGE in predictive performance
- End-to-end classifiers were feasible for some models; OpenAI o3 and Claude Opus 4 completed end-to-end pipelines
- OpenAI o3 achieved ~86.7% mean accuracy for KD vs MIS-C end-to-end; TB: ~76.3–77.6%; ME/CFS showed limited gains

QC result: Pass.

393: Hidden Resistance: tNGS Reveals Rifampicin and Bedaquiline Resistance in Eswatini

Gustavo Barra — Wed, 17 Jun 2026 07:55:51 +0000

Vambe D et al., Nature Communications - This study reports the programmatic introduction of targeted next-generation sequencing (tNGS) in Eswatini and shows that tNGS detected large amounts of rifampicin and bedaquiline resistance missed by routine diagnostics. Among 234 patient samples, tNGS reclassified many infections, revealed frequent co-occurrence of rpoB I491F and Rv0678 mutations, and guided treatment changes with high treatment success in a clinical subset. Key terms: tNGS, rifampicin-resistance, rpoB I491F, bedaquiline resistance, Eswatini.

Study Highlights:
tNGS detected rifampicin resistance in 159/234 strains, substantially more than Xpert Ultra, LPA, or MGIT pDST, and identified 101 strains with the rpoB I491F mutation (96 solo). Mutations in Rv0678 associated with bedaquiline/clofazimine resistance were found in 87 strains, occurring in 55% of rifampicin-resistant isolates and frequently co-occurring with rpoB I491F. Routine diagnostics under-classified resistance leading to incorrect regimen selection for many patients. In a subset of 59 patients with clinical data, tNGS-informed changes were made for 53% and treatment success was 88%.

Conclusion:
Programmatic tNGS in Eswatini closed a major diagnostic gap by identifying rifampicin resistance due to rpoB I491F and widespread Rv0678-associated bedaquiline resistance undetected by routine tests, enabling regimen changes and prompting reconsideration of current treatment algorithms and resistance classifications.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Targeted next-generation sequencing implementation in Eswatini identifies rifampicin and bedaquiline resistance undetected by routine diagnostic testing

First author:
Vambe D

Journal:
Nature Communications

DOI:
10.1038/s41467-026-73551-w

Reference:
Vambe D, Kay A, Ziyane M, et al. Targeted next-generation sequencing implementation in Eswatini identifies rifampicin and bedaquiline resistance undetected by routine diagnostic testing. Nat Commun. 2026. https://doi.org/10.1038/s41467-026-73551-w

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/hidden-resistance-tngs-eswatini

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-06-17.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the main results and implications discussed in the transcript: programmatic tNGS implementation, diagnostic gaps (I491F), BDQ resistance via Rv0678, comparison with routine diagnostics, regimen changes and outcomes, and WHO classification implications.
- transcript topics: Diagnostic escape and rpoB I491F; tNGS programmatic implementation in Eswatini; BDQ resistance and Rv0678 mutations; Comparison of tNGS with Xpert Ultra, LPA, and MGIT pDST; Clinical impact: treatment changes and outcomes; WHO tuberculosis resistance classifications and implications

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- tNGS detected rifampicin resistance in 159/234 samples (68%), with 96 of these carrying the rpoB I491F mutation
- Rv0678 mutations (bedaquiline/clofazimine resistance) found in 87 strains, present in 55% of RR isolates and commonly co-occurring with rpoB I491F
- Routine diagnostics under-classified resistance: Xpert Ultra detected RR in about 32% of samples; LPA and MGIT pDST around 20%
- tNGS-informed treatment changes occurred in 53% (31/59) of patients with complete clinical data, with 88% (52/59) treatment success
- Transmission of BDQ-resistant strains suggested; only one of 48 patients with prior TB exposure had bedaquiline exposure

QC result: Pass.

392: GWAS of Cocaine Self-Administration in Heterogeneous Stock Rats

Gustavo Barra — Fri, 12 Jun 2026 18:56:00 +0000

Lara MK et al et al., Nature Communications - Large GWAS in 836 outbred HS rats identifies six loci linked to cocaine self-administration traits, highlighting Ces1 carboxylesterase genes and other loci overlapping human substance-use genetics. Key terms: cocaine use disorder, GWAS, Heterogeneous Stock rats, Ces1, addiction-like behavior.

Study Highlights:
The study performed a genome-wide association analysis in 836 Heterogeneous Stock rats tested in extended-access cocaine self-administration paradigms and derived 27 behavioral traits. Six genome-wide significant loci were identified, including a chromosome 19 locus containing missense variants in Ces1c and Ces1d that are orthologous to human CES1 and associated with post-infusion interval. SNP-based heritability for traits was modest (h2 = 0.07–0.16) with the first LgA principal component showing the highest heritability (h2 = 0.16). Several loci contained coding variants and eQTL/sQTLs in brain regions, and one locus overlapped the rat homolog of human TRAK2.

Conclusion:
This largest-to-date rat GWAS of cocaine self-administration implicates drug-metabolizing carboxylesterases (Ces1c/Ces1d) and multiple neural genes in addiction-like behaviors, supports cross-species links to human SUD loci such as TRAK2, and highlights CES1-related pharmacological strategies as a potential avenue for follow-up.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Genome-wide association study of cocaine self-administration behavior in Heterogeneous Stock rats

First author:
Lara MK et al

Journal:
Nature Communications

DOI:
10.1038/s41467-026-73694-w

Reference:
Lara MK et al., Genome-wide association study of cocaine self-administration behavior in Heterogeneous Stock rats. Nature Communications (2026). https://doi.org/10.1038/s41467-026-73694-w

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/gwas-cocaine-hs-rats-ces1

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-06-12.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited portions of the transcript that cover: HS rat GWAS design and results; the chromosome 19 Ces1c/Ces1d locus and its link to post-infusion interval; metabolic role of Ces1 in cocaine breakdown; cross-species Trak2 findings; Rasd2/Gnas brain-region eQTLs; PC1 heritability; and broader discussion of implications an
- transcript topics: Gwas in heterogeneous stock rats and six significant loci; Chromosome 19 Ces1c/Ces1d locus and post-infusion interval; Carboxylesterase Ces1 enzymes metabolizing cocaine; Trak2/TRAK2 cross-species overlap with human CUD; Rasd2 and Gnas expression in nucleus accumbens and cortex; LgA PC1 addiction-like behavior and heritability

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Six genome-wide significant associations identified for cocaine self-administration traits in HS rats
- Chromosome 19 locus containing Ces1c and Ces1d associated with post-infusion interval
- Ces1 enzymes metabolize cocaine and influence duration/intensity of effects
- Trak2 is the rat ortholog of human TRAK2 and overlaps human CUD GWAS signals
- Rasd2 and Gnas show brain-region eQTLs related to cocaine response
- LgA PC1 addiction-like behavior explains ~55% of variance with SNP-based heritability up to 0.16

QC result: Pass.

391: The Kaufmann Protocol — Why We Age and How to Stop It

Gustavo Barra — Fri, 12 Jun 2026 17:07:33 +0000

Dr. Sandra Kaufmann, The Kaufmann Anti-Aging Institute - Dr. Sandra Kaufmann — physician, scientist and athlete — set out to understand aging and fight it with science. This episode is a guided overview of her book, featured with the author's permission: why our cells age (mitochondria, genetic information systems, quality control and maintenance, immunity, and waste management) and the families of anti-aging molecules she reviews (resveratrol, astaxanthin, NAD, curcumin, metformin, melatonin and more) — framed as an informed, individualized approach rather than a quick fix. Key terms: aging, longevity, anti-aging molecules, cellular biology, Kaufmann Protocol.

Study Highlights:
The book maps aging onto cellular causes — declining mitochondria, genetic information systems, cellular quality control and maintenance, immune changes, and waste management — and then reviews the leading molecules and adjuvants that target these pathways. Dr. Kaufmann turns the science into the basis for an informed, personalized plan, stressing that it is not a diet or quick fix and that decisions about supplements should be made together with a physician.

Conclusion:
Aging has identifiable biological drivers, and a science-literate, individualized approach — discussed with a physician — can help people age more deliberately rather than passively. Presented as Dr. Kaufmann's perspective, featured with the author's permission.

Title: The Kaufmann Protocol: Why We Age and How to Stop It
Reference: Kaufmann, S.C. The Kaufmann Protocol: Why We Age and How to Stop It. Jacob Cerny (Ed.), Ross Goldstein (Illus.). Kaufmann Anti-Aging Institute, 2018. ISBN 978-0-692-08904-0.
ISBN: 978-0-692-08904-0

License:
This episode is a guided overview of the book "Why We Age and How to Stop It: The Kaufmann Protocol" by Dr. Sandra Kaufmann, featured and adapted with the kind permission of the author.

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.castos.com/episodes/kaufmann-protocol-why-we-age

QC:
This episode is a guided overview of the book "Why We Age and How to Stop It — The Kaufmann Protocol" by Dr. Sandra Kaufmann, featured with the author's kind permission and reviewed for editorial accuracy.

QC Summary:
- verdict: pass
- review mode: book overview (author-authorized)
- framing: presented as the author's perspective and synthesis
- note: educational content only — not medical advice; decisions about supplements should be made with a physician

390: Daunorubicin, Mutual Destruction, and Layered Antiphage Defense

Gustavo Barra — Tue, 09 Jun 2026 05:15:29 +0000

Gätgens C et al., PNAS - This episode examines how DNA-intercalating molecules like daunorubicin block bacteriophage infection at an early stage, causing an abortive-infection-like outcome via toxic phage products and showing synergy with nucleic-acid targeting defenses. Key terms: daunorubicin, abortive infection, bacterial immunity, phage-host interactions, DNA intercalators.

Study Highlights:
Using the E. coli BASEL phage collection, the authors mapped taxon-specific phage sensitivities to daunorubicin and other intercalators. For the Tequintavirus Bas33, daunorubicin blocks infection after first-step transfer, restricting expression to pre-early genes and preventing genome replication. Continued expression of these pre-early host-takeover genes leads to host cell death driven by toxic phage products, a process described as mutual destruction. Daunorubicin can act synergistically with restriction-modification systems to prevent accumulation of toxic phage products and enable population survival.

Conclusion:
DNA-intercalating small molecules act as a chemical layer of bacterial antiphage defense that can block infection at defined stages and, depending on host context and additional immune systems, produce outcomes ranging from mutual destruction to population-level protection via synergy with nucleic-acid targeting defenses.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
DNA-intercalating antiphage molecules trigger abortive infection through mutual destruction and synergize with bacterial immunity

First author:
Gätgens C

Journal:
PNAS

DOI:
10.1073/pnas.2602073123

Reference:
Gätgens C., Rackow B., Ernst L., et al. DNA-intercalating antiphage molecules trigger abortive infection through mutual destruction and synergize with bacterial immunity. PNAS. 2026;123(23):e2602073123. https://doi.org/10.1073/pnas.2602073123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/daunorubicin-mutual-destruction

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-06-09.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the central mechanistic narrative and experimental results: daunorubicin action after first-step transfer, pre-early gene expression, mutual destruction phenotype, phage-specific sensitivity (Bas33 vs T4), and synergistic effects with RM systems EcoRV and EcoP1_I; plus methodological approaches and discussed li
- transcript topics: DNA-intercalating chemical defense concept; Daunorubicin action on BASEL phage collection; First-step transfer and pre-early gene expression; Mutual destruction vs abortive infection phenotype; Phage taxonomic sensitivity patterns (Bas33 vs T4); Restriction-modification systems and daunorubicin synergy

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Daunorubicin blocks Bas33 infection after first-step transfer (FST), with transcription largely restricted to pre-early genes
- Pre-early gene products drive host DNA degradation leading to a mutual destruction outcome
- Bas33 is daunorubicin-sensitive, whereas the model Tevenvirinae phage T4 shows resistance to daunorubicin
- A1 and A2 pre-early genes reside in the first 9% of Bas33 genome and are involved in host takeover; transcription of these genes is affected by daunorubicin
- EcoP1_I RM system provides strong synergy with daunorubicin, with eight recognition sites in the pre-early region contributing to protection
- Synergy between daunorubicin and RM systems can shift outcomes from Abi-like cell death to population survival

QC result: Pass.

389: Crotonylation impedes c-Myc oncogenic activity

Gustavo Barra — Tue, 09 Jun 2026 05:15:19 +0000

PNAS - This study identifies crotonylation as a posttranslational modification of c-Myc that reduces its transcriptional and oncogenic activity. Key lysines K289 and K298 are crotonylated; loss of crotonylation (including a cancer-derived K298N mutant) enhances Skp2 binding and tumorigenesis. Key terms: c-Myc, crotonylation, Skp2, posttranslational modification, oncogenesis.

Study Highlights:
The authors mapped ten crotonylated lysine residues on c-Myc and identified K289 and K298 as critical sites. Mutating these residues (2R or 8R mutants) increased c-Myc transcriptional activity, cell proliferation, colony formation, and promoter occupancy. Mechanistically, loss of crotonylation strengthened c-Myc binding to the E3 ligase Skp2 and reduced binding to p14ARF, linking crotonylation status to Skp2-mediated activation and turnover. A cancer-derived K298N mutation recapitulated enhanced transcriptional activity and produced larger xenograft tumors in mice.

Conclusion:
Crotonylation at specific C-terminal lysines restrains c-Myc oncogenic activity by limiting Skp2 interaction; disruption of this modification (including K298N) promotes transcriptional activation and tumor growth.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Crotonylation impedes c-Myc oncogenic activity

Journal:
PNAS

DOI:
10.1073/pnas.2530020123

Reference:
https://doi.org/10.1073/pnas.2530020123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/crotonylation-impedes-c-myc-activity

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-06-09.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited core scientific narrative: discovery of c-Myc crotonylation in human cells, identification of K289 and K298, mutational analyses (2R/8R), mechanistic link to Skp2 and transcriptional activation, in vivo K298N mutation and xenograft data, gut microbiota and crotonyl-CoA biology, and structural context via AlphaF
- transcript topics: c-Myc crotonylation in human cells; K289 and K298 crotonylation sites; crotonylation-deficient mutants 2R/8R and proliferation; Skp2 interaction and ARF competition; transcriptional activation and promoter occupancy; K298N cancer-derived mutant in vivo

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- c-Myc is crotonylated in human cells at K289 and K298.
- Crotonylation reduces binding of c-Myc to Skp2, dampening transcriptional activation.
- Crotonylation-deficient mutants (2R and 8R) increase cellular proliferation and colony formation across multiple cell lines.
- The cancer-derived K298N mutation shows increased transcriptional activity and oncogenic potential in vitro and in vivo.
- K289R and K298R substitutions abolish crotonylation at these sites and enhance Skp2 binding while reducing ARF interaction.
- AlphaFold predicts crotonylation drives a more compact, less disordered c-Myc conformation, imp...

388: Base by Base | Episode 388 — In situ CAR‑macrophage alleviates liver fibrosis

Gustavo Barra — Tue, 09 Jun 2026 05:15:10 +0000

Huang X et al., Proceedings of the National Academy of Sciences (PNAS) - This episode summarizes a PNAS study reporting CD163‑targeted lipid nanoparticles that deliver FAP‑specific CAR mRNA to liver macrophages in situ, producing CAR‑macrophages that clear activated hepatic stellate cells and promote fibrosis resolution in mouse models. Key terms: FAP‑CAR, macrophage, lipid nanoparticles, liver fibrosis, MMP12.

Study Highlights:
The authors engineered CD163 antibody–conjugated LNPs (αCD163/LNP‑FAPCAR) to selectively transduce liver macrophages with FAP‑targeting CAR mRNA, yielding in situ CAR‑macrophages. CAR‑M showed enhanced phagocytosis and cytotoxicity toward FAP+ hepatic stellate cells and activated Syk/MyD88/NF‑κB signaling, with induction of MMP12. In multiple mouse fibrosis models (CCl4, BDL, MCD diet), treatment reduced ECM and fibrosis markers, improved histology and hepatocyte regeneration, and reshaped macrophage subsets toward MMP12+ scar‑resolving states. Safety profiling showed no major organ toxicity in treated mice, though immunogenicity and off‑target distribution require further study.

Conclusion:
αCD163/LNP‑FAPCAR enables in situ generation of CAR‑macrophages that selectively eliminate FAP+ activated HSCs, reprogram macrophages toward reparative MMP12+ phenotypes, and reverse liver fibrosis in preclinical models, supporting further translational and safety evaluation.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
mRNA‑laden LNP‑enabled in situ CAR‑macrophage alleviates liver fibrosis via inhibiting activated HSCs and modulating the immune microenvironment

First author:
Huang X

Journal:
Proceedings of the National Academy of Sciences (PNAS)

DOI:
10.1073/pnas.2534673123

Reference:
Huang X, Wang J, Hao J, et al. mRNA‑laden LNP‑enabled in situ CAR‑macrophage alleviates liver fibrosis via inhibiting activated HSCs and modulating the immune microenvironment. Proc. Natl. Acad. Sci. U.S.A. 2026;123(22):e2534673123. doi:10.1073/pnas.2534673123. Published May 29, 2026.

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/in-situ-car-macrophage-liver-fibrosis

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-06-09.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript sections detailing αCD163/LNP-FAPCAR design, CAR-M macrophage generation in vivo, in vitro phagocytosis/cytotoxicity, in vivo fibrosis outcomes, scRNA-seq SAM/MMP12 reprogramming, human macrophage applicability, and safety considerations.
- transcript topics: CD163-targeted LNPs delivering FAPCAR mRNA; CAR-M macrophage architecture (CD3zeta with CD28); In vitro phagocytosis and cytotoxicity against FAP+ cells; Syk/Myd88/NF-kB signaling and MMP12 induction; In vivo mouse liver fibrosis models and outcomes; Biodistribution and persistence of αCD163/LNP-FAPCAR

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Targeting activated HSCs via FAP expression using CAR-M strategy
- CD163-targeted LNPs deliver FAPCAR mRNA to hepatic macrophages in situ
- CAR design includes CD3ζ signaling and CD28 costimulation
- In vitro CAR-M show markedly increased phagocytosis and cytotoxicity toward FAP+ cells
- In vivo mouse models show reduced hydroxyproline, ALT, ECM deposition and improved histology
- scRNA-seq reveals expansion of MMP12+ scar-associated macrophages (SAM)

QC result: Pass.

387: Homotypic Dengue Reinfections and Long-Term Antibody Decay

Gustavo Barra — Tue, 09 Jun 2026 05:14:59 +0000

Andrade J et al., PNAS - Analysis of three long-term cohorts in the Philippines and Thailand shows antibody titers wane over years and that homotypic dengue reinfections are common and required to explain population-level age–titer patterns. Key terms: dengue, homotypic reinfection, antibody kinetics, cohort study, mathematical modelling.

Study Highlights:
The authors analyzed serology and PCR surveillance from three cohorts (N = 4,268) in Cebu, Philippines and Kamphaeng Phet, Thailand with up to 11 years of follow-up. Individual titers after infection show biexponential decay: a rapid short-term fall (~2 months half-life) followed by a slow long-term decline (half-life ~4–8 years) that slows with age. Catalytic models that allow waning homotypic immunity and reinfection are required to reproduce observed age-specific infection rates and mean titers, estimating many individuals experience multiple homotypic reinfections across life in high-endemic settings.

Conclusion:
Waning long-term antibody titers and consequent homotypic reinfections are a key feature of endemic dengue transmission; vaccines that mimic natural infection may not provide lifelong protection and control strategies should account for repeated immune-stimulating events across ages.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Long-term antibody dynamics challenge the paradigm of lifelong homotypic immunity to dengue virus

First author:
Andrade J

Journal:
PNAS

DOI:
10.1073/pnas.2606206123

Reference:
Andrade J, Mitard de Girardie A, Huang AT, et al. Long-term antibody dynamics challenge the paradigm of lifelong homotypic immunity to dengue virus. PNAS. 2026;123(22):e2606206123. doi:10.1073/pnas.2606206123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/homotypic-reinfection-dengue

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-06-09.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript's coverage of dengue immunity dynamics, cohort data, subclinical infection prevalence, modeling of homotypic reinfection, age-related patterns, and public health/vaccine implications. Also checked limitations and caveats discussed in the article are echoed in the transcript.
- transcript topics: DENV serotypes and lifelong immunity paradigm; Cohort data and serology methods (PRNT, HI); Subclinical infections and catalytic modeling; Two-phase antibody decay (short-term and long-term); Homotypic reinfection and population immunity; Age-specific infection risk and force of infection

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Three cohorts totaling N = 4,268 participants across Cebu, Philippines and Kamphaeng Phet, Thailand
- Approximately 94% of infections are subclinical
- Antibody titers show biexponential decay after infection: a rapid short-term drop followed by a slower long-term decline
- Short-term half-life around 2 months; long-term half-life on the order of years (varying by cohort; Philippines ~6.7 years; Thailand ~4.0 years)
- By age ~40 in highly endemic settings, ~60% of individuals have experienced a homotypic reinfection
- Mean population titers peak in early adulthood (Philippines ~22 years; Thailand ~48 years) and slowly decline thereafter

QC result: Pass.

386: Genome Doubling and the Bioeconomy

Gustavo Barra — Fri, 05 Jun 2026 07:43:06 +0000

Peeters MKR et al., Proceedings of the National Academy of Sciences (PNAS) - A perspective outlining how genome doubling (polyploidy) reshapes genomes, phenotypes, and ecological interactions and how its immediate effects can be harnessed across agriculture, aquaculture, industrial biotechnology, and medicine to advance a sustainable bioeconomy. Key terms: polyploidy, bioeconomy, genetic diversity, stress tolerance, biotechnology.

Study Highlights:
Polyploidization (whole-genome duplication) often produces novel phenotypes by shifting gene expression, metabolism, and morphology, which can increase biomass, diversify metabolites, and enhance stress tolerance. The paper synthesizes applications across green, blue, white, and red bioeconomies, including crop improvement, algal biofuel and pharmaceutical production, polyploid industrial strains, and ploidy-based biocontainment in aquaculture. Practical methods discussed include induced polyploidy, doubled-haploid breeding, triploid sterility, and adaptive laboratory evolution. Outcomes are promising but variable and require careful phenotypic, ecological, and evolutionary assessment due to risks like genomic instability.

Conclusion:
Polyploidization is a shared mechanism that can generate increased genetic diversity, expanded metabolic capacity, and altered morphology useful across bioeconomy sectors, but its benefits are variable and must be paired with rigorous phenotypic and ecological evaluation to manage risks and guide responsible innovation.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Polyploidy: A macromutational force pushing bioeconomic developments

First author:
Peeters MKR

Journal:
Proceedings of the National Academy of Sciences (PNAS)

DOI:
10.1073/pnas.2522065123

Reference:
Peeters MKR & Van de Peer Y (2026). Polyploidy: A macromutational force pushing bioeconomic developments. Proc. Natl. Acad. Sci. U.S.A. 123:e2522065123. https://doi.org/10.1073/pnas.2522065123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/polyploidy-bioeconomy

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-06-05.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the core scientific content: mechanics of polyploidy, induction methods (Colchicine, DH breeding, triploidy, shocks), giga s effects, cross-domain applications (green/blue/white/red), and cancer-related polyploidy dynamics.
- transcript topics: Polyploidy as a macro mutation and its continuum (auto- vs allo-polyploidy); Induction methods for polyploidy (Colchicine, chemical induction, DH breeding, triploidy, shocks); Gigas effect and biomass/bioproduct implications; Green bioeconomy: crops, biomass, and biofuels; Blue bioeconomy: triploid fish and polyploid algae; White bioeconomy: polyploid microbes in bioprocessing

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Polyploidy is a macromutation that reshapes genomes, phenotypes, and ecological interactions
- Gigas effect: genome doubling increases cell and nuclear size, boosting biomass and organ size
- Doubled haploid (DH) breeding fixes traits quickly in a single generation in crops
- Triploidy in aquaculture creates sterile fish, aiding growth and ecological containment
- Industrial yeast can be engineered to carry up to 32 copies of the genome
- Polyploidy in bacteria (e.g., Deinococcus radiodurans) supports bioremediation efforts

QC result: Pass.

385: Growth under Pressure: Polyploidy Induced by Stress

Gustavo Barra — Thu, 04 Jun 2026 19:17:56 +0000

Sarabia Olivera L et al., PNAS - A perspective that surveys how diverse stresses trigger whole‑genome doubling (polyploidy) across fungi, plants, and animals, outlines common cell‑cycle mechanisms that produce polyploid cells, and evaluates the beneficial and detrimental consequences for genomes, cells, tissues, and applied contexts. Key terms: polyploidy, endocycles, oxidative stress, genome instability, regeneration.

Study Highlights:
The authors review evidence that many stresses — including temperature extremes, pharmacological agents, genotoxic insults, nutrient changes, infection, cell loss, and ROS — promote polyploidy across fungi, plants, and animals. Mechanistically, these stresses commonly act by perturbing the mitotic cell cycle via mitotic bypass, endoreplication, or failed cytokinesis. Polyploidy can enable tissue regeneration and buffer genomes but also increases genome instability, aneuploidy, and altered tissue function. Determining when polyploidy is adaptive versus harmful is presented as a key research priority for medicine and agriculture.

Conclusion:
Stress commonly induces polyploidy through conserved cell‑cycle alterations; its effects are context dependent, offering short‑term resilience or regeneration but often promoting genomic instability and long‑term functional costs, motivating cross‑discipline studies to understand mechanisms and applications.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Growth under pressure: The pros and cons of polyploidy induced by stress

First author:
Sarabia Olivera L

Journal:
PNAS

DOI:
10.1073/pnas.2522063123

Reference:
Sarabia Olivera L, Belato PB, Silva J, Selmecki A, Fox DT, Roeder AHK. Growth under pressure: The pros and cons of polyploidy induced by stress. PNAS. 2026;123(22):e2522063123. doi:10.1073/pnas.2522063123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/growth-under-pressure-polyploidy-stress

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-06-04.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript sections describing (1) diverse stress triggers and cell-cycle bypass mechanisms leading to polyploidy, (2) ROS as a unifying stress signal, (3) consequences at genome, cellular, and tissue levels, and (4) implications for therapy and agriculture; compared with the canonical article.
- transcript topics: Stress-induced polyploidy triggers; Mitotic bypass and cytokinesis failure; ROS signaling and DNA damage response; Genomic instability and aneuploidy; Tissue regeneration vs senescence; Clinical and agricultural implications

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Transcript describes diverse stresses triggering polyploidy (temperature, pharmacological, genotoxic, nutrient, infection, tissue loss).
- ROS accumulation is presented as a universal master switch driving polyploidy.
- Polyploidy buffers the genome but promotes genomic instability and aneuploidy over time.
- Polyploidy enables rapid tissue regeneration but long-term limits include senescence and loss of proliferative capacity.
- Therapeutic implication: sequential therapies can target polyploid cells after induction.
- Parasites exploit polyploid host cells (e.g., Plasmodium infecting polyploid hepatocytes).

QC result: Pass.

384: RNA Brake on Cholera Phage: CisR Controls CTXϕ

Gustavo Barra — Wed, 03 Jun 2026 11:48:03 +0000

Haycocks JRJ et al., PNAS - This episode examines the discovery of CisR, a small RNA produced from the 3’UTR of prtV in Vibrio cholerae, which posttranscriptionally represses the CTXϕ-encoded cep mRNA via Hfq-mediated base-pairing. CisR accumulation is controlled by HapR and CRP and processed by RNase E, linking quorum sensing and carbon status to phage activation. We discuss the experimental evidence showing CisR lowers Cep protein levels and limits CTXϕ production under induction conditions. Key terms: small RNA, CTXϕ, Vibrio cholerae, Hfq, quorum sensing.

Study Highlights:
Researchers identified CisR as a ~50-nt sRNA derived from the 3’UTR of prtV that requires RNase E for processing and Hfq for stability and action. RIL-seq and reporter assays show CisR base-pairs with the cep mRNA ribosome binding site to inhibit translation, and deletion or overexpression of cisR respectively increases or decreases Cep levels and extracellular CTXϕ DNA after induction. Transcription of the vca0224-prtV-cisR operon is directly activated by HapR and CRP, linking CisR to quorum sensing and carbon catabolite signals. The work positions a core-genome sRNA as a posttranscriptional regulator that modulates a horizontally acquired phage life cycle.

Conclusion:
CisR is a 3’UTR-derived sRNA that integrates cell-density and metabolic signals to repress CTXϕ coat protein production via Hfq-dependent base-pairing with cep, thereby limiting phage production under stress and coordinating phage activation with host physiology.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
A 3’UTR-derived small RNA modulates the life cycle of the cholera toxin–encoding filamentous phage, CTXϕ

First author:
Haycocks JRJ

Journal:
PNAS

DOI:
10.1073/pnas.2535142123

Reference:
Haycocks JRJ, O’Driscoll E, Sprenger M, Thriene K, Jung E-M, Siemers M, Lippegaus A, Krautwurst S, Grainger DC, Papenfort K. A 3’UTR-derived small RNA modulates the life cycle of the cholera toxin–encoding filamentous phage, CTXϕ. PNAS. 2026;123(23):e2535142123. doi:10.1073/pnas.2535142123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/cisr-controls-ctxphi-life-cycle

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-06-03.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Substantively audited the transcript sections describing CisR origin, CisR-cep interaction, HapR/CRP regulation, RIL-seq mapping, and functional impact on CTXϕ production under induction conditions.
- transcript topics: CTXϕ life cycle and filamentous phage biology; CisR discovery from prtV 3’UTR and RNase E processing; HFQ and RIL-seq methodology to map RNA interactions; CisR-cep base-pairing and translational repression; HapR and CRP regulation of prtV-cisR transcription; CisR impact on CTXϕ production during MMC induction

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- CisR is produced from the 3’ end of the prtV mRNA and is released via RNase E processing.
- CisR base-pairs with cep mRNA near its ribosome binding site to inhibit translation, with Hfq facilitating the interaction.
- Transcription of the prtV-cisR transcript requires HapR and CRP; the vca0224-prtV-cisR promoter is cooperatively regulated by HapR and CRP and bound by both factors.
- Deletion of cisR increases Cep protein levels and CTXϕ production under stress; overexpression of CisR reduces Cep and CTXϕ output.
- RIL-seq demonstrates Cep as a major CisR target, with around 80% of CisR interactions directed at cep under virulence conditions.
- RNase E activity is required for CisR maturation/accumulation; mature CisR is not detected in an RNase E–deficient background.

QC result: Pass.

383: Genetics of the Circulating Proteome: pQTLs, Pathways, and Disease Links

Gustavo Barra — Tue, 02 Jun 2026 05:12:10 +0000

Koprulu M et al., Cell - A 38-cohort proteogenomic meta-analysis of up to 78,664 people maps fine‑mapped protein quantitative trait loci (pQTLs) across 1,116 circulating proteins, uses machine learning to assign trans effector genes, and triangulates genetic and observational evidence to highlight disease mechanisms and therapeutic opportunities. Key terms: proteogenomics, protein QTLs, N-linked glycosylation, Mendelian randomization, drug repurposing.

Study Highlights:
The study meta-analyzed antibody-based proteomic data across 38 cohorts (n up to 78,664) and identified 24,738 fine-mapped pQTL credible sets for 1,116 proteins, including 5,040 cis and 19,698 trans pQTLs. Machine-learning effector-gene assignment for trans-pQTLs revealed enriched pathways and cell types that regulate plasma proteins, with N-linked glycosylation and liver/hepatocyte signals prominent. Systematic causal inference and triangulation with observational biomarker studies identified candidate drug targets and repurposing signals (e.g., TYK2, furin) but also showed limited concordance between cis genetic instruments and measured protein–disease associations.

Conclusion:
Large-scale multi-cohort proteogenomics uncovers widespread distal genetic regulation of the circulating proteome, identifies biological pathways and tissues that shape plasma protein levels (notably N-linked glycosylation and hepatic/immune contributors), and provides genetic evidence to prioritize biomarkers and drug targets while highlighting discordance between genetic and observational signatures that requires careful interpretation.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Multi-cohort proteogenomic analyses reveal genetic effects across the proteome and diseasome

First author:
Koprulu M

Journal:
Cell

DOI:
10.1016/j.cell.2026.03.049

Reference:
Koprulu M., Smith-Byrne K., Ferolito B.R., et al., 2026. Multi-cohort proteogenomic analyses reveal genetic effects across the proteome and diseasome. Cell 189, 3339–3357. https://doi.org/10.1016/j.cell.2026.03.049

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/multi-cohort-proteogenomics-pqtl-diseasome

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-06-02.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript sections describing trans-pQTL dominance, effector-gene mapping, N-linked glycosylation, tissue/cell-type enrichment, MR concordance issues, and clinical exemplars (TYK2 for RA, NT-proBNP for heart failure, extracellular furin).
- transcript topics: Trans-pQTL paradigm and global regulatory architecture; Cis vs trans pQTL landscape and study scale; Olink proximity extension assay methodology; Effector gene assignment and pathway/cell-type enrichment; N-linked glycosylation as a key trans-regulatory pathway; Clinical translation: TYK2 and rheumatoid arthritis

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Study design: up to 78,664 participants across 38 cohorts
- Proteins measured: 1,161 targets; 24,738 pQTLs (5,040 cis; 19,698 trans)
- cis pQTLs vs trans pQTLs: ~20% cis, ~80% trans
- N-linked glycosylation enriched among trans-pQTL effector genes
- Effector genes linked to liver/hepatocytes and immune cells
- Discordance between cis-based MR and observational data; limited concordance

QC result: Pass.

382: How animal blood cells evolved from unicellular ancestors

Gustavo Barra — Tue, 02 Jun 2026 03:15:10 +0000

Nagahata Y et al., PNAS - A transcriptome-driven reconstruction of blood cell evolution shows modern animal blood lineages arose by repurposing an ancestral unicellular toolkit. The study traces macrophage-like origins, a bilaterian mast/killer split, and later deuterostome/vertebrate innovations. Key terms: blood cell evolution, macrophage, mast cell, Fos, thymus.

Study Highlights:
The authors used cross-species transcriptomics and TF-focused phylogenies to show that the metazoan blood cell program traces to a premetazoan toolkit governed by Fos, producing macrophage-like initial blood cells. They infer a first major bifurcation at the origin of Bilateria that gave rise to a mast/killer lineage equipped with granular proteases specialized for antiparasitic defense. Deuterostome and vertebrate ancestors then diversified this mast lineage into T/NK and erythrocyte/thrombocyte branches while B cells emerged from the macrophage branch, and a prototypic thymus formed at tunicate gill edges. Murine hematopoiesis retains vestiges of this history: macrophage and mast potentials are widely preserved and ancient HSC-like progenitors persist.

Conclusion:
Blood cell diversity in animals represents a Fos-mediated repurposing of an ancestral unicellular program, with macrophage-like cells as the earliest blood lineage and subsequent bilaterian and deuterostome innovations producing mast/killer, lymphoid, and erythroid branches.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Animals have expanded the evolutionary legacy of unicellular ancestors in blood cells

First author:
Nagahata Y

Journal:
PNAS

DOI:
10.1073/pnas.2528110123

Reference:
Nagahata Y, Ishidae T, Satou Y, Nishimura Y, Kaitani R, Leong JCK, Oda-Ishiie I, Carmona-Rivas M, Najle SR, Ruiz-Trillo I, Kohtsuka H, Abeg S, Ikuta K, Miura T, Kawamoto H, Casacuberta E, Ogasawara M, Irieda N. Animals have expanded the evolutionary legacy of unicellular ancestors in blood cells. PNAS. 2026;123(23):e2528110123. doi:10.1073/pnas.2528110123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/base-by-base-382-blood-cell-evolution

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-06-02.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the spoken content describing the article’s core evolutionary timeline for blood cells, Fos-driven regulatory origins, macrophage-like ancestries, bilaterian mast/killer divergence, lineage branching to T/NK and erythrocyte/thrombocyte, B cell origin from macrophages, thymus evolution at gill edges, and implica
- transcript topics: Origin of blood cells at the metazoan root and Fos-driven premetazoan toolkit; Cross-species transcriptomics and transcription factor phylogeny; Macrophage-like primitive blood cells; Divergence of mast/killer lineage at Bilateria origin and granzyme-containing cells; Erythrocyte/thrombocyte lineage derived from mast/killer cells; B cells arising from macrophages

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Initial blood cells were macrophage-like phagocytes inherited from unicellular ancestors and governed by Fos.
- First bilaterian divergence produced a mast/killer lineage with granular proteases for antiparasitic defense.
- erythrocyte/thrombocyte lineage originated from the mast/killer lineage.
- B cells originated from macrophage lineage.
- A prototypic thymus formed at the gill edges in a chordate ancestor, with tunicate gill edge expression of Foxn1/4 and Notch ligands.
- Modern hematopoiesis recapitulates evolutionary history, with Fos activity retained in macrophage/mast lineages and a reverse-chronology differentiation pattern.

QC result: Pass.

381: Light-written spatial barcodes enable tunable multiomic sequencing (BALI)

Gustavo Barra — Mon, 01 Jun 2026 06:45:41 +0000

Battistoni G et al., PNAS - This paper presents BALI, a light-driven method that writes combinatorial DNA spatial barcodes directly onto biomolecules in tissue by iterative photocleavage and ligation, enabling user-defined, scalable spatial profiling of RNA, chromatin accessibility, or both from the same section and automation via a LightScribe instrument. Key terms: spatial multiomics, photocaged ligation, BALI, LightScribe, chromatin accessibility.

Study Highlights:
BALI uses a photocaged ligation root and patterned UV illumination to direct iterative DNA ligations that assemble combinatorial spatial barcodes in situ. The method achieves tunable spatial resolution down to ~3 µm and can scale barcode complexity from a few regions to theoretical millions by increasing barcode digits. As proof of concept, the authors profiled transcriptomes and chromatin accessibility in defined regions of embryonic and adult mouse brain and combined both readouts in a single-section multiomic workflow, showing concordance with established datasets. They also built the LightScribe instrument to automate combinatorial barcode writing and demonstrated automated encoding of hundreds of regions.

Conclusion:
BALI couples light-directed combinatorial ligation with standard sequencing workflows to offer histology-aware, tunable, and scalable spatial multiomic profiling with subcellular resolution and an accessible automation path, enabling targeted high-throughput studies across large sample sets.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Spatially tuneable multiomic sequencing using light-driven combinatorial barcoding of molecules in tissues

First author:
Battistoni G

Journal:
PNAS

DOI:
10.1073/pnas.2527896123

Reference:
Battistoni G, Torres-Garcia S, Sia CY, Corriero S, Boquetale C, Williams E, et al. Spatially tuneable multi-omics sequencing using light-driven combinatorial barcoding of molecules in tissues. Proc Natl Acad Sci U S A. 2026;123(21):e2527896123. doi:10.1073/pnas.2527896123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/bali-light-driven-combinatorial-barcoding

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-06-01.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript sections describing the BALI method, UV uncaging, iterative ligation, LightScribe automation, and multiomic validation (RNA and ATAC) as well as scalability and cost considerations; compared these claims with the canonical article.
- transcript topics: Spatial omics trade-offs and the need for histology-driven boundaries; BALI: Barcoding by Activated Linkage of Indexes; UV uncaging, ligation cycles, and barcode encoding; LightScribe automation with DMD mirrors; RNA profiling in embryonic mouse brain regions; Chromatin accessibility (ATAC) profiling in brain tissue

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 5
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- BALI writes combinatorial spatial barcodes directly onto target molecules in situ using patterned UV light
- Subcellular spatial resolution ~3 μm is demonstrated
- Ligation efficiency per cycle is ~86%, with ~48% overall encoding efficiency for thousands of regions
- RNA profiling (transcriptome) and chromatin accessibility (ATAC) can be measured in the same tissue section (multiomics)
- Validation against laser capture microdissection (LCM) shows concordant RNA expression profiles
- LightScribe automates barcode writing with digital micromirror devices (DMD) and demonstrated automation writing 256 barcodes

QC result: Pass.

380: Prime-SGE maps drug-resistance variants at scale

Gustavo Barra — Fri, 29 May 2026 09:59:10 +0000

Abadie FMC et al., Cell Genomics - Abadie et al. present prime‑SGE, a pooled prime‑editing framework that installs thousands of precise point mutations across multiple oncogenes and identifies drug‑resistance variants by sequencing integrated pegRNAs after positive‑selection with kinase inhibitors. The method resolved known resistance mutations (e.g., EGFR C797S, KRAS G12 variants), uncovered less-characterized candidates, compared resistance landscapes across covalent and non‑covalent EGFR inhibitors, and validated resistant edits in vivo. Key terms: prime editing, drug resistance, EGFR, KRAS, multiplex screening.

Study Highlights:
Prime‑SGE uses libraries of barcoded pegRNAs/epegRNAs delivered at low MOI into PEmax‑expressing, MLH1‑knockout cell lines to program thousands of point mutations and read out variant abundance by sequencing integrated guides after drug selection. In pooled screens across eight oncogenes and three EGFR inhibitors, prime‑SGE recovered established resistance mutations (EGFR C797S, KRAS G12 variants) and identified less-characterized hits (e.g., EGFR Q791, Y801). Distinct resistance landscapes emerged for covalent versus non‑covalent EGFR inhibitors, and barcodes showed many resistant clones arose from independent editing events. Prime‑edited resistant cells formed tumors in osimertinib-treated xenografts, demonstrating in vivo relevance.

Conclusion:
Prime‑SGE enables scalable, positive‑selection profiling of thousands of precise point mutations across the genome to identify and compare drug‑resistance variants, though sensitivity is limited by variable prime editing efficiency. The approach can prioritize resistance variants for follow-up and inform inhibitor development and choice.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
A multiplex, prime editing framework for identifying drug resistance variants at scale

First author:
Abadie FMC

Journal:
Cell Genomics

DOI:
10.1016/j.xgen.2026.101167

Reference:
Abadie FMC, Suiter CC, Smith NT, et al. A multiplex, prime editing framework for identifying drug resistance variants at scale. Cell Genomics. 2026;6:101167. doi:10.1016/j.xgen.2026.101167

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/prime-sge-drug-resistance-variants

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-05-29.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript's sections describing Prime-SGE concept, the scale of edits, key resistance mutations (EGFR C797S, KRAS G12 variants, Q791, Y801), inhibitor contexts (osimertinib, sunvozertinib, CH7233163), in vivo xenograft validation, and limitations (editing efficiency, false negatives).

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Prime-SGE enables multiplexed installation of thousands of precise edits across multiple genes with readout by integrated pegRNA barcodes
- Large-scale screens used 3,825 epegRNAs programming 1,220 single-nucleotide mutations across seven oncogenes and three TKIs
- Resistance mutations include EGFR C797S and KRAS G12 variants; novel mutations such as EGFR Q791 and Y801 described
- KRAS G12 variants (G12C, G12S, G12V, G12D, etc.) confer resistance to osimertinib, sunvozertinib, and CH7233163
- Distinct resistance landscapes emerge for covalent (osimertinib, sunvozertinib) versus non-covalent (CH7233163) inhibitors
- In vivo validation shows prime-edited cells (e.g., C797S pool) form tumors under osimertinib treatment in xenografts

QC result: Pass.

379: Long reads reveal hidden structural and repeat variation in autism

Gustavo Barra — Wed, 27 May 2026 11:35:15 +0000

Mortazavi M et al., Cell Genomics - PaperCast Base by Base discusses a long-read whole-genome sequencing study of 267 individuals from 63 families that increased detection of structural variants and tandem repeats, resolved complex rearrangements, linked repeat expansions to methylation at FMR1, and estimated rare-variant contributions to ASD heritability. Key terms: long-read sequencing, structural variants, tandem repeats, autism, methylation.

Study Highlights:
The authors performed long-read WGS (PacBio HiFi and Oxford Nanopore) on 267 individuals and integrated calls with prior short-read data, increasing detection of gene-disrupting SVs by 33% and TRs by 38%. They discovered novel exonic de novo and somatic-mosaic SVs and characterized a previously undescribed class of nested DUP-DEL complex rearrangements. Joint phasing and methylation analysis identified deletions affecting imprinted genes (e.g., ADNP2) and showed that intermediate FMR1 CGG expansions (35–54 repeats) associate with allele-specific hypermethylation. Burden and heritability analyses indicate rare SVs, TRs, and damaging SNVs together explain a measurable fraction of ASD heritability, though power is limited by sample size.

Conclusion:
Long-read WGS uncovers substantial previously hidden structural and repeat variation and enables combined phased genetic and methylation analysis to improve functional interpretation in ASD, but larger cohorts and deeper coverage are needed to refine associations and heritability estimates.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Long-read genome sequencing improves detection and functional interpretation of structural and repeat variants in autism

First author:
Mortazavi M

Journal:
Cell Genomics

DOI:
10.1016/j.xgen.2026.101186

Reference:
Mortazavi M., Guevara J., Diaz J., et al., 2026. Long-read genome sequencing improves detection and functional interpretation of structural and repeat variants in autism. Cell Genomics 6, 101186. https://doi.org/10.1016/j.xgen.2026.101186

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/long-read-wgs-autism-structural-repeat-variants

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-05-27.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Substantively audited portions describing LR-WGS methodology, SV/TR detection gains, mosaic and de novo SVs (STK33), large balanced rearrangements, nested DUP-DEL SVs, imprinting (ADNP2), FMR1 gray-zone methylation, ASD heritability, and study limitations/future directions.
- transcript topics: LR-WGS methods and methylation calling; Structural variants and tandem repeats detection gains; Mosaic and de novo SVs (STK33) and functional impact; Complex DUP-DEL rearrangements; Imprinted genes and ADNP2; FMR1 CGG repeats and methylation, XCI independence

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Cohort: LR-WGS performed on 267 individuals from 63 ASD families (including 117 offspring, 76 cases, 41 controls; 126 parents).
- Sequencing platforms: PacBio HiFi and Oxford Nanopore (ONT); mean read lengths ~11.3 kb for HiFi and ~5.6 kb for ONT.
- LR-WGS boosted detection of SVs by 33% and TRs by 38% compared to SR-WGS.
- Out of ~44,000 SVs detected (non-TR SVs), ~16,488 were novel LR-WGS-specific variants; ~7,084 were SR-WGS-specific.
- TR regions: LR-WGS genotyped ~98% of annotated TR regions; many TR regions not accessible by SR-WGS.
- Mosaic STK33 duplication identified, maternal haplotype, present in ~50% of cells, with an in-frame 66 amino acid duplication.

QC result: Pass.

378: Dominant-negative PSMB8 variants stall immunoproteasome assembly

Gustavo Barra — Tue, 26 May 2026 09:48:50 +0000

Wijngaard R et al., The American Journal of Human Genetics - Researchers describe seven individuals with monoallelic PSMB8 missense variants that impair immunoproteasome assembly, causing early-onset immunodeficiency and variable systemic inflammation via a dominant-negative mechanism. Key terms: PSMB8, immunoproteasome, PRAAS-ID, immunodeficiency, proteasome assembly.

Study Highlights:
Seven individuals from five families carrying distinct monoallelic PSMB8 variants presented with neonatal-onset immunodeficiency, B cell lymphopenia, hypogammaglobulinemia, and variable inflammatory disease. Structural modeling predicted destabilization of proteasome interfaces, and complexome profiling plus native assays showed reduced fully assembled immunoproteasomes with accumulation of a ∼440-kDa assembly intermediate. Mutant PSMB8 precursors accumulated, incorporation into 20S/26S complexes was reduced, immunoproteasome-specific activity decreased, and integrated stress response genes were induced. These data support a shared dominant-negative mechanism disrupting immunoproteasome biogenesis and immune signaling.

Conclusion:
Monoallelic PSMB8 missense variants impair incorporation of β5i into assembling immunoproteasomes, stalling biogenesis, reducing immunoproteasome abundance and activity, and producing clinically variable immunodeficiency with systemic inflammation consistent with PRAAS-ID.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Monoallelic PSMB8 variants cause PRAAS with immunodeficiency through impaired immunoproteasome assembly

First author:
Wijngaard R

Journal:
The American Journal of Human Genetics

DOI:
10.1016/j.ajhg.2026.04.015

Reference:
Wijngaard R., van der Made C.I., Kalkan Uçar S., et al. Monoallelic PSMB8 variants cause PRAAS with immunodeficiency through impaired immunoproteasome assembly. Am J Hum Genet. 2026;113:1–19. doi:10.1016/j.ajhg.2026.04.015

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/monoallelic-psmb8-praas-id-immunoproteasome-assembly

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-05-26.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Substantive audit of immunoproteasome biology, dominant-negative mechanism of monoallelic PSMB8 variants, complexome profiling findings (440-kDa assembly intermediate, reduced IP abundance), functional consequences (IP activity reduction, ISR activation), and clinical implications described in the transcript.
- transcript topics: Immunoproteasome structure and SP/IP distinction; Dominant-negative PSMB8 variants and mechanism; Complexome profiling methodology and IP assembly intermediates; Impaired IP biogenesis and 440-kDa intermediate; ISR activation and immune signaling effects; Clinical features: B cell lymphopenia, hypogammaglobulinemia, leukocyte inclusions

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Monoallelic PSMB8 variants cause PRAAS-ID via dominant-negative impairment of immunoproteasome assembly
- Mutant PSMB8 subunits are inefficiently incorporated into immunoproteasomes, leading to defective IP biogenesis and reduced IP activity
- Complexome profiling reveals accumulation of a ~440-kDa IP assembly intermediate with assembly factors
- The 440-kDa intermediate is catalytically inactive despite partial assembly
- Leukocyte vacuolization and inclusions observed in blood/bone marrow
- B cell lymphopenia and hypogammaglobulinemia, frequently requiring IVIG

QC result: Pass.

377: ProteomeLM — proteome-scale language modeling for interactomes and essential genes

Gustavo Barra — Tue, 26 May 2026 09:48:42 +0000

Malbranke C et al., Proceedings of the National Academy of Sciences (PNAS) - ProteomeLM is a transformer-based language model trained on complete proteomes that produces contextualized protein embeddings and attention signals which recover protein–protein interactions unsupervised and support supervised PPI and gene essentiality prediction across diverse taxa. Key terms: proteome language model, protein–protein interactions, gene essentiality, ProteomeLM, deep learning.

Study Highlights:
ProteomeLM was trained on ~32,000 proteomes using ESM‑C embeddings and a custom polar loss to reconstruct masked protein embeddings in proteome context. Its attention heads encode protein–protein interactions without supervision and distinguish direct physical binding, complex membership, and broader functional associations. As a fast first-pass filter it outperforms amino-acid coevolution (DCA) in recall while reducing compute by orders of magnitude. Downstream supervised models—ProteomeLM-PPI and ProteomeLM-Ess—achieve state-of-the-art cross-species PPI prediction and strong gene essentiality prediction that generalizes to held-out and synthetic minimal genomes.

Conclusion:
Representing proteins in whole-proteome context yields interpretable attention signals that capture functional and physical relationships, enabling rapid, accurate interactome screening and improved gene essentiality prediction across the tree of life.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
ProteomeLM: A proteome-scale language model enables accurate and rapid prediction of protein–protein interactions and gene essentiality across taxa

First author:
Malbranke C

Journal:
Proceedings of the National Academy of Sciences (PNAS)

DOI:
10.1073/pnas.2524201123

Reference:
Malbranke C, Zalaffi GP, Bitbol A-F. ProteomeLM: A proteome-scale language model enabling accurate and rapid prediction of protein–protein interactions and gene essentiality across taxa. Proc Natl Acad Sci U S A. 2026;123:e2524201123. doi:10.1073/pnas.2524201123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/proteomelm-interactomes-essentiality

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-05-26.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited substantive scientific content in transcript: ProteomeLM architecture, functional encoding, polar loss, unsupervised PPI via attention, speed/screening benefits, supervised PPI (ProteomeLM-PPI), gene essentiality predictions (ProteomeLM-Ess), and cross-species/minimal cells.
- transcript topics: ProteomeLM architecture and training on whole proteomes; Functional encoding using orthology (OrthoDB); Polar loss and avoiding reliance on coarse functional encoding; Attention coefficients encoding protein-protein interactions (PPI) in unsupervised manner; Unsupervised PPI detection and protein complex membership; Speed and scalability of whole-interactome screening vs DCA

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- ProteomeLM trained on ~32,000 annotated proteomes spanning the tree of life and uses a functional encoding via orthologous groups (OrthoDB).
- ProteomeLM’s attention coefficients encode PPI without supervision (no interaction labels during training).
- ProteomeLM enables fast whole-interactome screening and is substantially faster than DCA (up to six orders of magnitude); inference under 10 minutes per proteome on a single GPU.
- Unsupervised PPI performance in Escherichia coli: a single attention head (head7, layer3) achieves AUC = 0.92.
- ProteomeLM can distinguish direct interactions, same-complex interactions, and genetic associations; ribosome and TRiC/CCT complex analyses yield high AUC (>= 0.99 for some tests).
- ProteomeLM-PPI achieves state-of-the-art supervised PPI predictions across species; ProteomeLM-Ess predicts gene essentiality; best reported AUC = 0.93 with layer-8 embeddings from

QC result: Pass.

376: Pfh1's Balancing Act: Unwinding, Rewinding, and the Role of Mitochondrial SSB

Gustavo Barra — Tue, 26 May 2026 09:48:32 +0000

Ortiz-Rodríguez M et al., Proceedings of the National Academy of Sciences (PNAS) - Single-molecule optical tweezers and fluorescence reveal how the S. pombe Pif1-family helicase Pfh1 alternates ATP-dependent unwinding and ATP-modulated rewinding at replication-fork-like substrates, and how mitochondrial SSB spRim1 tunes those activities. Key terms: Pfh1 helicase, Pif1-family, DNA unwinding, spRim1, single-molecule.

Study Highlights:
Using single-molecule optical tweezers and fluorescence, the authors show Pfh1 performs ATP-dependent unwinding–rewinding cycles with an intrinsic ~20–22 bp processivity. Contacts with the translocating strand modulate apparent ATP affinity while engagement of the displaced strand limits maximum unwinding velocity. The mitochondrial SSB spRim1 binds the displaced strand, disrupts those contacts, and increases unwinding and rewinding velocities. Rewinding is ATP-dependent and proceeds via a sliding-back mechanism rather than strand switching.

Conclusion:
Pfh1 balances unwinding and rewinding through coordinated ATP-dependent interactions with both fork strands; binding of spRim1 to the displaced strand disrupts inhibitory helicase–strand contacts and accelerates fork dynamics, providing a mechanistic framework for how Pif1-family helicases promote replication fork progression without disrupting replisome organization.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Regulation of Pfh1 helicase activity by nucleic acid interactions and mitochondrial SSB

First author:
Ortiz-Rodríguez M

Journal:
Proceedings of the National Academy of Sciences (PNAS)

DOI:
10.1073/pnas.2602528123

Reference:
Ortiz-Rodríguez M, Singh SP, Cao-García FJ, Galletto R, Ibarra B. Regulation of Pfh1 helicase activity by nucleic acid interactions and mitochondrial SSB. PNAS. 2026;123(21):e2602528123. doi:10.1073/pnas.2602528123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/pfh1-helicase-unwinding-rewinding

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-05-26.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript sections describing Pfh1 unwinding/rewinding cycles, force and ATP dependencies, spRim1 modulation, DNA fork vs RNA–DNA fork experiments, and the proposed sliding-back mechanism and its biological relevance.
- transcript topics: Pfh1 helicase function and 5'-3' directionality; Unwinding–rewinding cycles and ~20 bp processivity; ATP concentration and force dependencies (Km(f), Vmax); Role of spRim1 in DNA fork unwinding/rewinding; RNA–DNA fork experiments and strand-switching debate; Rewinding mechanism and ATP hydrolysis effects

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- PfH1 operates via unwinding–rewinding cycles with coordination between fork strands
- Intrinsic unwinding processivity is ~20 bp (not extending beyond ~22 bp per burst)
- Unwinding velocity increases with ATP and is modulated by force via Km(f) and Vmax
- spRim1 binds displaced strand, increasing unwinding velocity on the DNA fork to ~115 bp/s and shortening inter-burst recovery
- spRim1 accelerates rewinding on the DNA fork; on RNA–DNA forks, spRim1 does not stimulate unwinding/rewinding
- RNA–DNA fork experiments support a sliding-back mechanism over strand-switching

QC result: Pass.

375: Biallelic DSCAM LoF: a syndromic NDD with nystagmus and cone-pathway retinal dysfunction

Gustavo Barra — Tue, 26 May 2026 09:48:23 +0000

Douzgou Houge S et al., Human Genetics and Genomics Advances - This paper reports six individuals with biallelic loss-of-function DSCAM variants, delineating a recessive syndrome of moderate-to-severe neurodevelopmental delay with poor language, early focal seizures, hypotonia, short stature, and characteristic rotatory/vertical nystagmus with cone-pathway retinal dysfunction. Key terms: DSCAM, neurodevelopmental delay, nystagmus, retinal dysfunction, electroretinography.

Study Highlights:
The authors describe six patients (including four newly reported) with homozygous or compound heterozygous predicted loss-of-function variants in DSCAM. All individuals share moderate-to-severe neurodevelopmental delay, impaired language, frequent hypotonia, and short stature, with focal seizures in some. A consistent ophthalmic phenotype of rotatory/vertical nystagmus and poor vision was observed, and ERG in two patients showed relative rod preservation but marked cone-pathway dysfunction, implicating cone-associated bipolar cells. The clinical and electrophysiological findings align with animal models showing disrupted retinal lamination and mosaic spacing caused by loss of DSCAM.

Conclusion:
Biallelic DSCAM loss-of-function defines a rare recessive neurodevelopmental syndrome characterized by motor and cognitive impairment and a distinctive, developmentally origin retinal dysfunction primarily affecting the cone pathway detectable by ERG.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Biallelic loss-of-function variants in DSCAM cause a neurodevelopmental syndrome with nystagmus and retinal dysfunction

First author:
Douzgou Houge S

Journal:
Human Genetics and Genomics Advances

DOI:
10.1016/j.xhgg.2026.100622

Reference:
Douzgou Houge S., Bredrup C., Wivestad Jansson R., Bojovic O., Aljamal B.M., Al-Otaibi M., Plomp A.S., Motazacker M.M., van Genderen M.M., Mellgren A., Alkuraya H., Hikmat O., Haukanes B.I., Alkuraya F.S., Douzgos Houge G. Biallelic loss-of-function variants in DSCAM cause a neurodevelopmental syndrome with nystagmus and retinal dysfunction. Human Genetics and Genomics Advances 7, 100622 (July 9, 2026). https://doi.org/10.1016/j.xhgg.2026.100622.

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/biallelic-dscam-neurodevelopmental-nystagmus

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-05-26.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: The transcript covers the study’s core claims: DSCAM function and retinal organization, genetic evidence for biallelic LoF variants, the neurodevelopmental phenotype, ERG findings showing cone pathway impairment with rod preservation, animal-model context, consanguinity patterns, and ASD-related discussions.
- transcript topics: DSCAM role in retinal self-avoidance and patterning; Genetic identification of DSCAM LoF variants via trio exome sequencing; Clinical phenotype: neurodevelopmental delay, language impairment, seizures, hypotonia, short stature; Ophthalmic phenotype and ERG-based retinal function (cone vs rod); Cone-associated bipolar cells in the retina as the site of dysfunction; Animal-model evidence (chicken retina and DSCAM KO mice) for retinal organization

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Six individuals with biallelic DSCAM loss-of-function variants described in the study
- Cone-pathway dysfunction with preserved rod-pathway function demonstrated by ERG in some individuals
- Cone-associated bipolar cells implicated as the site of dysfunction in the retina
- DSCAM is required for self-neuronal avoidance; animal models show retinal disorganization when DSCAM is disrupted
- Consanguineous parental relationships and twin pairs observed in the cohort
- Monoallelic DSCAM variants have been associated with autism in separate studies

QC result: Pass.

374: DNA-guided Cas12a reprogrammed to target RNA

Gustavo Barra — Fri, 22 May 2026 08:21:59 +0000

Wu X et al., Nature Biotechnology - The authors engineer synthetic PAM-containing DNA guides (crDNA) that bind Cas12a to form a deoxyribonucleoprotein (DNP) complex that recognizes and cleaves complementary RNA. Structural, biochemical and cellular data define a PAM-dependent activation route distinct from canonical RNA-guided systems and demonstrate applications in sensitive diagnostics and intracellular RNA knockdown. Key terms: DNA-guided Cas12a, crDNA, RNA targeting, SLEUTH diagnostic, RNA knockdown.

Study Highlights:
The team designed single-stranded PAM-bearing crDNA that assembles with Cas12a to form a stable DNP complex and recruit complementary RNA substrates. Cryo-EM and modeling show crDNA occupies the PI/WED/REC groove, preserves PAM engagement and positions an RNA–DNA heteroduplex for RuvC-mediated cleavage. DNA-guided Cas12a selectively binds and cleaves ssRNA, enables robust trans-cleavage across targets and orthologs, and supports an amplification-coupled SLEUTH diagnostic with attomolar sensitivity. In cells, phosphorothioate-stabilized crDNA with Cas12a produced sequence-specific knockdown of reporter and endogenous transcripts with minimal off-target signal.

Conclusion:
Cas12a can be reprogrammed into a DNA-guided, RNA-targeting effector: PAM-mediated crDNA engagement forms a catalytically competent complex that achieves sequence-specific RNA cleavage, enabling a new architecture for diagnostics and a proof-of-concept for intracellular RNA knockdown while highlighting stability and optimization challenges.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
DNA-guided CRISPR–Cas12a effectors for programmable RNA recognition and cleavage

First author:
Wu X

Journal:
Nature Biotechnology

DOI:
10.1038/s41587-026-03120-5

Reference:
Wu X., Lam W.H., Zhao Z., Feng X., Zhai Y., Hsing I.-M. DNA-guided CRISPR–Cas12a effectors for programmable RNA recognition and cleavage. Nature Biotechnology (2026). doi:10.1038/s41587-026-03120-5

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/dna-guided-cas12a-reprogrammed-to-target-rna

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-05-22.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited transcript sections describing crDNA design and PAM activation, structural data from cryo-EM, RNA targeting and cleavage mechanics, SLEUTH diagnostic workflow and performance, and intracellular RNA knockdown in cells.
- transcript topics: DNA-guided Cas12a concept and crDNA design; PAM-dependent activation and DNP formation; Cryo-EM structure and DNA–RNA duplex within Cas12a; Two-step binding kinetics (Kd1 and Kd2); Trans-cleavage activity and RNA targeting kinetics; SLEUTH diagnostic workflow and performance

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- DNA-guided Cas12a can target RNA using crDNA with PAM-dependent activation
- crDNA occupies PAM-interacting site to form a DNP complex and enables RNA targeting
- Cryo-EM shows a 20-bp DNA–RNA heteroduplex in the Cas12a binding channel with PAM engaging the PI domain
- RNA cleavage is Mg2+-dependent via the RuvC active site and exhibits trans-cleavage
- SLEUTH achieves attomolar sensitivity and 100% concordance with RT–qPCR on a limited SARS-CoV-2 set
- PS-modified crDNA enables intracellular RNA knockdown in HEK293T cells with 56% reduction in EGFP fluorescence and 76% reduction in EGFP mRNA, with minimal off-target effects

QC result: Pass.

373: Base by Base 373 — A ciliate rewrites UAA and UAG

Gustavo Barra — Thu, 21 May 2026 10:35:29 +0000

McGowan J et al., PLOS Genetics - Genome and transcriptome sequencing of an uncultured Oligohymenophorea ciliate (PL0344) reveals a novel nuclear genetic code in which UAA translates as lysine and UAG as glutamic acid, supported by suppressor tRNAs and phylogenomic context. Key terms: genetic code, ciliate, UAA, UAG, suppressor tRNA.

Study Highlights:
The authors assembled a macronuclear genome from low-input G&T-Seq data for Oligohymenophorea sp. PL0344 and found widespread in-frame UAA and UAG codons. Codetta and PhyloFisher analyses predict UAA→lysine and UAG→glutamic acid, and multiple corresponding suppressor tRNA genes were identified. UGA remains as a stop and is enriched as tandem stops in the 3' UTR, suggesting selection to limit readthrough. Phylogenomic mapping shows numerous independent genetic code changes across ciliates, making this the first reported case where UAA and UAG specify different amino acids.

Conclusion:
This study documents a previously unknown nuclear genetic code variant in a ciliate where UAA and UAG have distinct sense meanings, expanding known genetic code diversity and highlighting the need to consider noncanonical codes in genome annotation and evolutionary analyses.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Identification of a non-canonical ciliate nuclear genetic code where UAA and UAG code for different amino acids

First author:
McGowan J

Journal:
PLOS Genetics

DOI:
10.1371/journal.pgen.1010913

Reference:
McGowan J, Kilias ES, Alacid E, Lipscombe J, Jenkins BH, Gharbi K, et al. (2023) Identification of a non-canonical ciliate nuclear genetic code where UAA and UAG code for different amino acids. PLoS Genet 19(10): e1010913. https://doi.org/10.1371/journal.pgen.1010913

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/non-canonical-ciliate-code-373

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-05-21.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Substantively audited the transcript sections that discuss genetic code reassignments (UAA/UAG), suppressor tRNAs, UGA handling (stop/Sec), tandem stop codons, sequencing approach (G&T-Seq), and phylogenetic context.
- transcript topics: Canonical vs noncanonical genetic code in ciliates; UAA and UAG reassignment to Lys and Glu; Suppressor tRNA genes and wobble binding; G&T-Seq single-cell genome/transcriptome methodology; UGA stop codon usage and tandem stop codons; Phylogenomics and independent genetic code changes in ciliates

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- UAA codon reassigned to lysine and UAG codon reassigned to glutamic acid in PL0344
- Presence of multiple suppressor tRNA genes corresponding to UAA (Lys) and UAG (Glu)
- tRNA-SeC(UCA) identified, suggesting UGA can encode selenocysteine in addition to stop
- UGA codons enriched in the 3'-UTR downstream of genes as tandem stops to mitigate readthrough
- Genome assembly size around 69.7 Mb with thousands of transcripts and tRNA genes
- Wobble-coupling constraint circumvented; UAA and UAG have different meanings in this organism

QC result: Pass.

372: Genes, IQ and Socioeconomic Outcomes in Emerging Adults

Gustavo Barra — Wed, 20 May 2026 07:12:28 +0000

Kajonius PJ et al., Scientific Reports - This episode examines a twin-study analysis from the German TwinLife panel showing that cognitive ability at age 23 predicts socioeconomic status at age 27, and that much of this longitudinal association is explained by genetic factors rather than shared or unique environments. Key terms: cognitive ability, IQ, socioeconomic status, genetics, twin study.

Study Highlights:
Using TwinLife panel data, IQ measured at 23 predicted educational and occupational outcomes at 27 with phenotypic correlations typically above .30. Univariate twin models estimated IQ heritability at about 75% and substantial heritability for SES measures. Bivariate Cholesky decompositions found that genetics accounted for 69–98% of the IQ–SES association and that genetic correlations exceeded environmental correlations. These results held across two education and two occupation measures.

Conclusion:
In this emerging-adult sample, both IQ and SES showed sizable heritability and the longitudinal link from IQ to future SES was largely attributable to shared genetic influences, suggesting that research and policy should account for genetic contributions when interpreting individual socioeconomic trajectories.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Longitudinal associations between cognitive ability and socioeconomic status are partially genetic in nature

First author:
Kajonius PJ

Journal:
Scientific Reports

DOI:
10.1038/s41598-026-37786-3

Reference:
Kajonius PJ. Longitudinal associations between cognitive ability and socioeconomic status are partially genetic in nature. Scientific Reports. 2026;16:4315. doi:10.1038/s41598-026-37786-3

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/genes-iq-ses-twinlife

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-05-20.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Substantively audited sections covering: study design (TwinLife, MZ/DZ twins), measurement (CFT-20-R IQ at 23; education and occupation SES at 27), main results (heritability estimates; 69–98% genetic explanation of IQ–SES link; C factor minimal), pleiotropy pathways (direct and mediated), and discussion of limitations
- transcript topics: TwinLife study and sample characteristics; Measurement of IQ and SES; Univariate and bivariate twin-model analyses (ACE/AE; Cholesky/related description); Genetic and environmental contributions to IQ and SES; Genetic overlap and pleiotropy pathways; Limitations and policy implications

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- IQ23 heritability around 75%
- SES27 heritability for education around 49% (AE) and 66% (Casmin); occupation around 32% (ACE) and 71% (AE)
- Genetic factors explained 69–98% of the IQ–SES longitudinal association
- Occupational SES shows up to 98% genetic overlap with IQ
- Common environment (C) often minimal or dropped in best-fitting models
- Two pleiotropy pathways: direct (biological) pleiotropy and mediated pleiotropy

QC result: Pass.

371: Glial epigenomic dysregulation and genetic risk in tauopathies

Gustavo Barra — Tue, 19 May 2026 10:16:19 +0000

Han et al., Nature Communications - This study uses paired single-nucleus chromatin accessibility and gene expression profiling across Alzheimer’s disease, Pick’s disease and progressive supranuclear palsy to map disease-dynamic cis-regulatory elements (CREs). Dynamic chromatin changes concentrate genetic risk in glial cell states and co-regulated regulatory modules. Integrating GWAS, sn-eQTLs and MPRA validates functional noncoding variants that tune lysosomal, lipid and vesicular pathways. Experimental CRISPRa and histology support a stress-inducible SOX10-driven glial program linked to resilience. Key terms: snATAC-seq, tauopathies, microglia, chromatin accessibility, SOX10.

Study Highlights:
The authors profiled matched snATAC-seq and snRNA-seq from three brain regions across AD, PiD and PSP and defined cell-type-specific CREs and 50 subclusters. Disease-dynamic peaks concentrated in glia and disproportionately capture GWAS heritability, with PiD-linked mg.C4 microglia and PSP-linked ast.C1 astrocytes identified as risk-associated states. MPRA in microglial models and sn-eQTL integration validated functional regulatory variants that converge on MEF2C/SOX10 and SNARE-centered modules affecting lysosomal, sphingolipid and trafficking pathways. CRISPRa induction of SOX10 in iPSC-derived microglia under synaptosome stress recapitulated mg.C4 programs, and RNAscope/IHC confirmed SOX10+/PLP1+ glial states in human tissue.

Conclusion:
Dynamic, disease-context-specific chromatin remodeling in glia concentrates genetic risk into co-regulated regulatory modules that modulate lysosomal, lipid and vesicular pathways; these modules nominate SOX10-, MEF2- and SNARE-centered circuits as candidate modulators of glial resilience across tauopathies.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Single-nucleus epigenomic dysregulation unmasks genetic risk-associated neurodegenerative glia states

First author:
Han

Journal:
Nature Communications

DOI:
10.1038/s41467-026-73007-1

Reference:
Han, X., Rosenberg, G.M., Kisling, V.M. et al. Single-nucleus epigenomic dysregulation unmasks genetic risk-associated neurodegenerative glia states. Nat Commun (2026). https://doi.org/10.1038/s41467-026-73007-1

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/epigenomic-glial-genetic-risk-tauopathies

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-05-19.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript portions describing glial states mg.C4 microglia and ast.C1 astrocytes, regulatory networks (MEF2C/MEF2D), SOX10's role and ectopic expression, MPRA validation, CRISPRaSOX10 experiments, dynamic CREs and heritability findings, and study limitations.
- transcript topics: Glial states mg.C4 microglia and ast.C1 astrocytes across tauopathies; MEF2C/MEF2D regulatory modules linking to lysosomal and phagocytic pathways; SOX10 as a stress-responsive regulator and ectopic expression in glia; MPRA validation of regulatory variants in microglia (frVars); CRISPRa SOX10 activation in hiPSC-derived microglia and recapitulation of mg.C4 programs; Dynamic CREs and GWAS heritability enrichment across disorders

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Number of nuclei and samples studied: 682,667 high-quality nuclei from 41 brains
- Regions analyzed in main comparisons: Precentral Gyrus (PreCG) and insula; calcarine cortex excluded due to variability
- Identification of disease-associated glial states mg.C4 microglia and ast.C1 astrocytes
- Dynamic CREs enrich disease heritability, with PiD mg.C4 driving FTD heritability and PSP ast.C1 contributing PSP heritability
- MEF2C/MEF2D regulatory modules link to lysosomal and phagocytic pathways in mg.C4 microglia
- SOX10 is enriched/activated in mg.C4 and ast.C1 and acts as a stress-responsive regulator

QC result: Pass.

370: ICMT and INPP5E enable BRAFV600E tumor growth

Gustavo Barra — Mon, 18 May 2026 05:56:03 +0000

Yang X et al., Proceedings of the National Academy of Sciences - Genetic and pharmacologic inhibition of ICMT suppresses proliferation, invasion, and tumor growth in BRAFV600E-driven models and identifies INPP5E as an ICMT-dependent CAAX substrate whose membrane targeting supports melanoma growth. Key terms: ICMT, INPP5E, BRAFV600E, melanoma, UCM-1336.

Study Highlights:
ICMT genetic knockdown or pharmacologic inhibition (UCM-1336) reduced proliferation and invasion of BRAFV600E-mutant melanoma cells, decreased tumor growth in xenografts and mouse models, and retained activity in BRAF-inhibitor-resistant cells. ICMT inhibition reduced INPP5E carboxyl methylation, displaced INPP5E from membranes to the cytosol, and increased cellular PI(4,5)P2. Forced membrane targeting of INPP5E (Lyn-INPP5E) partially rescued proliferation and tumor growth during ICMT suppression. These results implicate an ICMT–INPP5E axis that supports BRAFV600E-driven tumor growth without measurable suppression of MAPK signaling.

Conclusion:
ICMT-dependent methylation and membrane targeting of INPP5E contribute to BRAFV600E-driven tumor growth, and ICMT inhibition (genetic or with UCM-1336) impairs melanoma growth including in BRAF-inhibitor-resistant models, highlighting ICMT as a context-dependent therapeutic vulnerability.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
ICMT supports BRAF
^V600E
-driven tumor growth by membrane targeting of the CAAX protein INPP5E

First author:
Yang X

Journal:
Proceedings of the National Academy of Sciences

DOI:
10.1073/pnas.2601795123

Reference:
Yang X, Qiao X, Schmidt S, et al. ICMT supports BRAFV600E-driven tumor growth by membrane targeting of the CAAX protein INPP5E. PNAS. 2026;123(20):e2601795123. doi:10.1073/pnas.2601795123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/icmt-inpp5e-brafv600e-membrane-targeting

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-05-18.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited sections describing ICMT/CAAX processing, INPP5E as an ICMT substrate, membrane targeting and PI(4,5)P2 effects, rescue experiments, in vitro/in vivo models, and therapeutic implications.
- transcript topics: ICMT and CAAX protein processing; INPP5E as an ICMT substrate and its membrane localization; Impact of ICMT inhibition on BRAFV600E melanoma cell proliferation and invasion; MAPK signaling independence from ICMT inhibition; In vivo models and genetic/pharmacologic ICMT suppression; Rescue experiments with Lyn-INPP5E and rescue implications

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- ICMT inhibition reduces BRAFV600E-driven melanoma cell proliferation and invasion in vitro and tumor growth in vivo.
- INPP5E is an ICMT-dependent CAAX substrate; ICMT inhibition reduces INPP5E methylation and displaces it from membranes.
- Displacement of INPP5E increases plasma membrane PI(4,5)P2, disrupting signaling and contributing to tumor cell death.
- Forced membrane targeting of INPP5E (LYN-INPP5E) partially rescues proliferation and tumor growth during ICMT suppression.
- Nontransformed fibroblasts show less sensitivity to ICMT inhibition, indicating a therapeutic window.
- MEK/ERK phosphorylation is not reduced by ICMT inhibition, indicating a MAPK-independent mechanism.

QC result: Pass.

369: NEK2 drives EBV-positive NHL pathogenesis

Gustavo Barra — Sat, 16 May 2026 10:45:51 +0000

White MC et al., PNAS - This episode reviews a PNAS study showing that the kinase NEK2 is upregulated by EBV and its latency proteins and that NEK2 inhibition with the irreversible inhibitor JH295 selectively kills EBV-positive non-Hodgkin lymphoma cells, lowers drug resistance, and reduces tumor burden in mouse models. Key terms: NEK2, EBV, non-Hodgkin lymphoma, LMP1, drug resistance.

Study Highlights:
EBV infection and the latency proteins EBNA1, LMP1, and EBNA2 increase NEK2 expression in human B cells and patient tumors. Genetic depletion or pharmacologic inhibition of NEK2 with JH295 selectively kills EBV-positive NHL cells and induces inflammatory, ROS-associated cell death with gasdermin D cleavage. NEK2 inhibition reduces LMP1 and c-myc expression, decreases ABC transporter expression and MRP1-mediated drug efflux, and sensitizes cells to doxorubicin. In xenograft and cord blood-humanized mouse models JH295 lowered tumor burden, reduced tumor incidence, and prolonged survival without observable toxicity.

Conclusion:
NEK2 is a promising therapeutic target in EBV-positive non-Hodgkin lymphoma; NEK2 inhibition by JH295 both kills malignant cells and reduces drug resistance and viral oncoprotein expression in preclinical models.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
NEK2 drives pathogenesis, drug resistance, and LMP1 expression in EBV-positive non-Hodgkin lymphoma

First author:
White MC

Journal:
PNAS

DOI:
10.1073/pnas.2535550123

Reference:
White MC, Lange PT, Stewart J, Damania B. NEK2 drives pathogenesis, drug resistance, and LMP1 expression in EBV-positive non-Hodgkin lymphoma. Proc Natl Acad Sci U S A. 2026;123:e2535550123. doi:10.1073/pnas.2535550123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/nek2-drives-ebv-positive-nhl

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-05-16.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited transcript passages on EBV-induced NEK2 upregulation, NEK2 inhibition mechanisms (ROS, gasdermin D), downstream effects (LMP1, c-Myc, beta-catenin, Bcl-2 family), MRP1/ABC transporters and drug resistance, and in vivo xenograft and cord blood–humanized mouse results.
- transcript topics: EBV-induced NEK2 upregulation in primary B cells; EBV latency proteins EBNA1, LMP1, EBNA2 drive NEK2 expression; JH295 NEK2 inhibitor and EBV+ NHL selectivity; Inflammatory cell death: ROS accumulation and gasdermin D cleavage; Downregulation of LMP1, c-Myc, beta-catenin; Bcl-2 family modulation; MRP1/MDR transporters and drug resistance reversal

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- EBV latency proteins EBNA1, LMP1, EBNA2 independently drive NEK2 upregulation
- Primary EBV infection increases NEK2 expression in human B cells
- NEK2 inhibition with JH295 induces inflammatory, ROS-associated cell death with gasdermin D cleavage in EBV-positive NHL
- EBV-positive NHL shows decreased LMP1 and c-myc expression following NEK2 inhibition
- NEK2 inhibition reduces MRP1/MDR transporter expression and activity, decreasing drug efflux and increasing chemosensitivity to doxorubicin
- JH295 reduces tumor burden and increases survival in NKTL xenograft and cord blood–humanized mouse models, with no observable systemic toxicity

QC result: Pass.

368: PARP1 and Amyloid: Protecting Neurons in a Familial AD Model

Gustavo Barra — Sat, 16 May 2026 10:45:41 +0000

Jhaldiyal A et al., PNAS - This episode summarizes a PNAS study showing that PARP1 activation links Aβ1-42 toxicity to DNA damage, amyloid accumulation, neuroinflammation, and cognitive deficits, and that genetic or pharmacologic PARP1 suppression reduces pathology in cells and 5XFAD mice. Key terms: PARP1, poly(ADP-ribose), Alzheimer's disease, amyloid beta, neurodegeneration.

Study Highlights:
CSF poly(ADP-ribose) (PAR) is elevated in patients with MCI and AD and negatively correlates with the Aβ42/40 ratio. Oligomeric Aβ1-42 activates PARP1 in primary cortical neurons, causing DNA damage and cell death that are prevented by PARP1 inhibitors or PARP1 genetic deletion. In 5XFAD mice, PARP1 knockout halves plaque burden, preserves synapses and neurons, reduces glial activation and inflammatory gene expression, and rescues spatial learning and memory. Mechanistically, PARP1 deficiency lowers BACE1, alters γ-secretase subunits (PSEN1 up, nicastrin down), and increases the Aβ-degrading enzyme NEP2.

Conclusion:
PARP1 is a critical mediator of Aβ-driven toxicity, amyloid accumulation, neuroinflammation, and cognitive decline in a familial AD model, and its inhibition may be a promising disease-modifying strategy.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
PARP1 deficiency mitigates amyloid pathology, neurodegeneration, and cognitive decline in a familial Alzheimer’s disease model

First author:
Jhaldiyal A

Journal:
PNAS

DOI:
10.1073/pnas.2525028123

Reference:
Jhaldiyal A., Kumari M., Guttman L. C., et al. PARP1 deficiency mitigates amyloid pathology, neurodegeneration, and cognitive decline in a familial Alzheimer’s disease model. PNAS (2026). DOI: 10.1073/pnas.2525028123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/parp1-amyloid-neurodegeneration-5xfad

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-05-16.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript sections describing CSF PAR elevation, Aβ42-induced PARP1 activation in neurons, in vitro neuroprotection by PARP inhibitors, in vivo 5XFAD/PARP1−/− outcomes (plaque burden, neuronal survival, gliosis, cognitive tests), APP metabolism changes, NEP2 involvement, inflammation, and translational cav
- transcript topics: CSF PAR elevation in MCI and AD and relation to Aβ42/40; Oligomeric Aβ42 activates PARP1 and induces DNA damage; Pharmacologic/genetic PARP1 inhibition confers neuroprotection in vitro; 5XFAD/PARP1−/− mice: reduced amyloid plaque burden and neuronal loss; APP processing changes: BACE1 reduction, PSEN1/nicastrin alterations, NEP2 up; Neuroinflammation and gliosis attenuation with PARP1 loss

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- CSF PAR levels are elevated in MCI and AD and inversely correlate with the Aβ42/40 ratio
- Oligomeric Aβ1-42 activates PARP1 and induces DNA damage; PARP1 inhibition or deletion confers neuroprotection in vitro
- PARP1 deficiency in 5XFAD mice reduces plaque burden (~50%) and preserves neurons and synapses while reducing gliosis and neuroinflammation
- PARP1 deficiency lowers APP processing toward reduced Aβ production (BACE1 decreased; PSEN1 up; nicastrin down) and increases NEP2-mediated Aβ degradation
- PARP inhibitors (e.g., veliparib, rucaparib, talazoparib) block Aβ-induced PAR accumulation and protect neurons in culture
- Translational considerations include blood-brain barrier crossing and long-term safety concerns for chronic PARP inhibition

QC result: Pass.

367: Ancestral Splice Variation Fuels Cichlid Jaw Diversification

Gustavo Barra — Fri, 15 May 2026 07:59:14 +0000

Singh P et al., PNAS - This paper compares alternative splicing (AS) and gene expression (GE) across 200 transcriptomes from oral and pharyngeal jaws of 18 haplochromine cichlid species across Lakes Victoria, Malawi, and Tanganyika. The authors show that rapid changes in AS, often from low-frequency ancestral isoforms and some novel isoforms, contributed more to early trophic diversification than shifts in GE. Key terms: alternative splicing, adaptive radiation, cichlids, gene regulation, craniofacial development.

Study Highlights:
Using 200 jaw transcriptomes spanning three East African cichlid radiations, the authors found that alternative splicing (AS) diverged faster than gene expression (GE) and was enriched for craniofacial and jaw morphogenesis genes. Most adaptive isoforms were present at low levels in nonradiating ancestral lineages and increased in frequency in radiating lineages, consistent with standing splice variation fueling rapid adaptation. A subset of novel isoforms evolved rapidly, some within a few thousand years, and mapped to candidate craniofacial genes such as col21a1. Younger radiations (Victoria, Malawi) showed stronger AS divergence while the older Tanganyika radiation displayed more GE differences.

Conclusion:
Ancestral alternative splice variation, supplemented by rapidly evolved novel isoforms, provided a labile reservoir of protein-coding diversity that likely enabled the extremely rapid trophic diversification of African cichlid radiations; integrating splicing into regulatory perspectives is essential to understand rapid adaptive evolution.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Ancestral splice variation is a key substrate for rapid diversification in African cichlids

First author:
Singh P

Journal:
PNAS

DOI:
10.1073/pnas.2516477123

Reference:
Singh P., Ahi E.P., Duenser A., Durdevic M., Gessl W., Schaeffer S., Gall J., Seehausen O., Sturmbauer C. Ancestral splice variation is a key substrate for rapid diversification in African cichlids. PNAS. 2026;123(20):e2516477123. doi:10.1073/pnas.2516477123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/ancestral-splice-variation-african-cichlids

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-05-15.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript sections describing AS vs GE dynamics, ancestral standing variation, novel isoforms (col21a1), lake-by-lake evolutionary patterns, and convergent/trophic evolution; cross-checked against the original article.
- transcript topics: Adaptive radiation and jaw anatomy in African cichlids; Gene expression vs alternative splicing (GE vs AS); Ancestral standing variation and novel isoforms; Temporal patterns: young vs old radiations (Victoria/Malawi vs Tanganyika); Key genes: col21a1 and craniofacial pathways; Convergent vs divergent regulation across radiations

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Transcript describes AS evolving faster than GE; AS divergence aligns with species/diet and not just tissue.
- Transcript cites ancestral standing variation: 86.0% of genes and 73.0% of isoforms present in riverine ancestors and radiations.
- Transcript notes novel isoforms (34 identified) with col21a1 isoforms linked to hypertrophied lips in Lake Victoria radiants.
- Transcript reports lake-by-lake patterns: Victoria/Malawi rely on AS for rapid jaw divergence; Tanganyika relies more on GE over time.
- Transcript mentions convergent differential expression in multiple lakes (e.g., odam) and convergent trophic evolution.
- Transcript emphasizes a two-phase view: AS provides rapid adaptive changes; GE provides longer-term tuning.

QC result: Pass.

366: BRCA1P1 suppresses antiviral and antitumor immunity

Gustavo Barra — Fri, 15 May 2026 07:55:56 +0000

Han YJ et al., Proceedings of the National Academy of Sciences (PNAS) - This episode examines a PNAS study showing that the BRCA1 pseudogene BRCA1P1 produces circular RNAs that suppress antiviral innate immunity in human cancers; depleting BRCA1P1 activates interferon-stimulated genes, increases apoptosis and chemosensitivity, and enhances immune clearance in preclinical models. Key terms: BRCA1P1, pseudogene, circular RNA, antiviral immunity, breast cancer.

Study Highlights:
BRCA1P1 is expressed broadly across human cancer cell lines and is elevated in breast tumors. The majority of BRCA1P1 transcripts are circular RNAs that bind the NF-κB subunit RelA to attenuate NF-κB–driven antiviral gene transcription. Loss of BRCA1P1 by ASO or CRISPR induces ISGs, IFNβ and TNF, increases apoptosis and sensitivity to chemotherapy, and enhances macrophage phagocytosis. In patient-derived organoids and humanized mouse xenografts BRCA1P1 depletion reduces tumor viability and increases T cell and M1 macrophage infiltration.

Conclusion:
BRCA1P1-derived circular RNAs act as immunosuppressive regulators of antiviral and antitumor immunity in human cancers, and targeting BRCA1P1 activates antiviral programs that reduce tumor growth and boost immune infiltration.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Regulation of antiviral and antitumor immunity by the BRCA1 pseudogene in human cancers

First author:
Han YJ

Journal:
Proceedings of the National Academy of Sciences (PNAS)

DOI:
10.1073/pnas.2528911123

Reference:
Han YJ, Zhang J, Shariff M, Wu S, Khramtsova G, Nguyen LC, Peiffer DS, Li N, Lewicka A, Moore M, Piccirilli JA, Olopade OI. Regulation of antiviral and antitumor immunity by the BRCA1 pseudogene in human cancers. Proc Natl Acad Sci U S A. 2026;123(19):e2528911123. doi:10.1073/pnas.2528911123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/brca1p1-pseudogene-antiviral-immunity

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-05-15.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript sections describing BRCA1P1 background, circular RNA nature, RelA/NF-κB interaction, depletion experiments (ASO/CRISPR), pancancer expression, antiviral gene upregulation, apoptosis, chemotherapy sensitivity, immune infiltration, PDOs, and humanized mouse models, plus clinical implications and de
- transcript topics: BRCA1P1 background and primate-specificity; BRCA1P1 circular RNA and RelA/NF-κB interaction; BRCA1P1 depletion methods (ASO, CRISPR) and pancancer scope; Antiviral gene induction and cytokine responses; Apoptosis and chemotherapy sensitivity after BRCA1P1 loss; Macrophage phagocytosis and T cell infiltration

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- BRCA1P1 is a primate-specific, chimeric BRCA1/RPLP1 pseudogene; majority of BRCA1P1 transcripts are circular RNAs (~70-80%).
- BRCA1P1 circRNA binds RelA (NF-κB p65) and suppresses NF-κB–driven antiviral gene transcription.
- BRCA1P1 depletion (via ASO or CRISPR) increases antiviral ISGs (IFIH1, IFIT3, OAS2) and cytokines (IFNB1, IL1B, TNF) across multiple cancer cell types.
- BRCA1P1 depletion induces apoptosis in cancer cells and increases sensitivity to doxorubicin, with minimal toxicity to nonmalignant cells.
- BRCA1P1 loss enhances macrophage phagocytosis and elevates CD3/CD4/CD8 T cell and CD86+ macrophage infiltration into tumors.
- BRCA1P1 depletion reduces viability of patient-derived organoids and decreases tumor volume in humanized mouse models.

QC result: Pass.

365: MEN1 mutations and menin inhibitor resistance

Gustavo Barra — Fri, 15 May 2026 06:56:43 +0000

Bourgeois et al., Nature Communications - This study used enhanced CRISPR base editor screens, structural biology, biochemical assays, and in vitro/in vivo selection to map MEN1 mutations that drive resistance to five clinical menin inhibitors and to explain their mechanisms. Key terms: MEN1, menin inhibitors, CRISPR base editing, drug resistance, KMT2A.

Study Highlights:
CRISPR base editor screens tiled MEN1 and profiled resistance to five clinical menin inhibitors, revealing shared (M327 I/V/T, G331D) and inhibitor-specific (C334R, E368K/V, V372A) substitutions. Co-crystal structures of mutant menin bound to each inhibitor explain resistance via steric clashes or disrupted interactions and correlate with measured Ki and cellular IC50 shifts. Orthogonal in vitro selection and PDX experiments show many predicted mutations arise spontaneously under drug pressure and that higher inhibitor potency or dosing can suppress or overcome some resistant clones. The particular amino acid substitution at a residue critically determines the magnitude and breadth of resistance.

Conclusion:
Enhanced CRISPR base editing combined with structural and biological validation maps a mutational landscape in MEN1 that can produce pan-class or drug-specific resistance to menin inhibitors; these data can guide clinical monitoring, choices between inhibitors, dosing strategies, and next-generation inhibitor design.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
CRISPR base editor screening identifies spectrum of MEN1 mutations impacting menin inhibitors in clinical trials

First author:
Bourgeois

Journal:
Nature Communications

DOI:
10.1038/s41467-026-72685-1

Reference:
Bourgeois, W., Rice, H.E., Wenge, D.V. et al. CRISPR base editor screening identifies spectrum of MEN1 mutations impacting menin inhibitors in clinical trials. Nat Commun (2026). https://doi.org/10.1038/s41467-026-72685-1

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/papercast-base-by-base-menin-mutations-365

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-05-15.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript sections describing the CRISPR base editor screen identifying MEN1 mutations that affect five clinical menin inhibitors, including shared vs inhibitor-specific mutations, biochemical and structural validation, and in vivo PDX confirmation, as well as dose-related resistance dynamics and limitatio
- transcript topics: Menin-KMT2A interaction and menin inhibitors in leukemia; CRISPR base editor screen design and MV4;11 cells; Shared and inhibitor-specific MEN1 mutations (M327, G331, T349, C334R, E368K/V, V372A); Biochemical binding: TR-FRET and Ki shifts; Structural insights: co-crystal structures; In vivo validation: PDX models

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Five inhibitors tested: DS-1594, JNJ-6617, KO-539, SNDX-5613, DSP-5336
- Base editing screen in MV4;11 A>G and C>T lines mutates MEN1 across residues; screen yields enriched residues near the KMT2A binding pocket
- Mutations show shared (pan-class) resistance, notably M327I and G331D, and inhibitor-specific resistance (C334R for DS-1594; E368K/V for DSP-5336; V372A for KO-539)
- Ki shifts measured by TR-FRET correlate with cellular IC50 shifts
- Co-crystal structures explain resistance via steric clashes or disrupted interactions
- In vivo PDX validation shows mutations arise under therapeutic pressure; higher potency can suppress or overcome resistance

QC result: Pass.

364: Peripheral C4 and Schizophrenia: A Neutrophil Gene–Protein Link

Gustavo Barra — Mon, 11 May 2026 22:15:32 +0000

Kalinowski A et al., PNAS - This study reports that C4 protein is enriched in human neutrophils and monocytes and that neutrophil C4 protein levels correlate with C4A gene copy number specifically in people with schizophrenia, linking peripheral innate immunity to disease-related biology. Key terms: schizophrenia, complement C4, neutrophils, monocytes, innate immunity.

Study Highlights:
Using public gene-expression data and fresh whole blood, the authors show C4 protein is primarily localized to neutrophils and monocytes. In a clinical cohort, neutrophil C4 protein positively correlated with C4A gene copy number in schizophrenia (Spearman rho = 0.63). Neutrophil and classical monocyte C4 protein were reduced in schizophrenia versus controls, and neutrophil C4 associated with perceived stress and symptom measures. Findings support a peripheral, cell-associated source of complement activation in schizophrenia.

Conclusion:
Neutrophils are a peripheral cellular reservoir of C4 that links C4A gene copy number to complement protein levels in schizophrenia, implicating innate immune cell mechanisms as potential contributors and targets for disease modification.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Peripheral complement C4 protein in schizophrenia: Association with gene copy number and immune cell subtypes

First author:
Kalinowski A

Journal:
PNAS

DOI:
10.1073/pnas.2536376123

Reference:
Kalinowski A., Macaubas C., Guo H., et al. Peripheral complement C4 protein in schizophrenia: Association with gene copy number and immune cell subtypes. PNAS. 2026;123(20):e2536376123. doi:10.1073/pnas.2536376123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/peripheral-c4-schizophrenia-neutrophil-link

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-05-11.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Substantive audit of the transcript’s core scientific narrative: peripheral C4 biology in SZ (cellular localization, genetic associations, plasma vs cellular activation), links to symptoms/stress, and translational implications, with attention to study limitations.
- transcript topics: Innate immunity and C4 in schizophrenia; C4 protein expression in neutrophils and monocytes; C4A gene copy number correlates with neutrophil C4 protein in SZ; Plasma C4 vs cell-associated C4 activation; Clinical associations: perceived stress and PANSS; Limitations and confounds (medication, BMI, sample size)

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- C4 protein is expressed and localized in neutrophils and monocytes (cellular localization, not plasma only)
- C4A gene copy number correlates with neutrophil C4 protein in schizophrenia (Spearman rho ≈ 0.63; P ≈ 0.012)
- In schizophrenia, neutrophil C4 protein is lower than controls after adjustment (BMI or related covariates; notable P-values in exploratory analyses)
- Plasma C4 did not show the same correlations with C4A gene copies, suggesting a non-plasma cellular source
- Neutrophil C4 protein depletion correlates with higher perceived stress (PSS) and PANSS general psychopathology in SZ
- Study limitations include all SZ participants being medicated; replication in medication-naive/first-episode samples is needed

QC result: Pass.

363: cfDNA size deconvolution reveals a 159‑bp nucleosomal pivot and tumor fragmentomic signatures

Gustavo Barra — Sat, 09 May 2026 19:42:48 +0000

Zhou Z et al., Nature Communications - This study develops a Lorentzian deconvolution model of cfDNA fragment length distributions across bodily fluids, identifies a ~159 bp component that demarcates intra- vs inter-nucleosomal fragments, and shows that intra-nucleosomal fragmentation entropy distinguishes tumor-derived ctDNA from non-tumor shortening. Key terms: cell-free DNA, fragmentomics, nucleosome, ctDNA, size deconvolution.

Study Highlights:
The authors modeled cfDNA size profiles as sums of Cauchy–Lorentz distributions with ~10 bp periodicity and applied deconvolution across plasma, saliva, urine, CSF and lymphatic fluid. A distinct ~159 bp component emerged as a pivot between intra- and inter-nucleosomal fragments. Tumor-derived ctDNA shows increased intra-nucleosomal fragmentation entropy and inverse amplitude changes across the 159 bp boundary, whereas phagocytosis-associated shortening increases intra-nucleosomal amplitude without raising entropy. The intra/inter-nucleosomal entropy ratio improved cancer detection performance relative to standard size-ratio metrics across multiple cohorts.

Conclusion:
Size deconvolution using Lorentzian components reveals nucleosomal structure in cfDNA, identifies a 159 bp demarcation between fragmentation regimes, and provides an entropy-based metric that enhances ctDNA detection while separating tumor-associated fragmentation from phagocyte-related signals.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Cell-free DNA size deconvolution resolves nucleosomal origins and reveals tumor-associated fragmentomic alterations

First author:
Zhou Z

Journal:
Nature Communications

DOI:
10.1038/s41467-026-72925-4

Reference:
Zhou Z, Cooper WN, Cheng Z, et al. Cell-free DNA size deconvolution resolves nucleosomal origins and reveals tumor-associated fragmentomic alterations. Nat Commun (2026). https://doi.org/10.1038/s41467-026-72925-4

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/cfdna-size-deconvolution-nucleosomal-origins

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-05-09.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Substantive auditing of the transcript's discussion of cfDNA fragmentology, Lorentzian deconvolution, the 159 bp pivot, entropy vs amplitude distinctions, Li-Fraumeni context, phagocytosis vs tumor fragmentation, and diagnostic performance metrics.
- transcript topics: cfDNA fragmentomics basics; Lorentzian size deconvolution and nucleosome structure; 159 bp boundary between intra- and inter-nucleosomal cfDNA; intra-/inter-nucleosomal amplitude and entropy ratios; ctDNA fragmentation entropy as cancer signature; phagocytosis vs tumor-derived fragmentation

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- cfDNA size profiles deconvoluted into Lorentzian components across multiple fluids with ~10 bp periodicity
- a ~159 bp component demarcates intra- vs inter-nucleosomal cfDNA
- intra-nucleosomal fragmentation entropy is elevated in ctDNA; phagocytosis-associated shortening increases amplitude but not entropy
- intra-/inter-nucleosomal entropy ratio improves cancer detection performance (gastric cancer AUC ~0.87; multi-cancer AUC ~0.81–0.85; stage-specific AUCs up to ~0.91)
- radiotherapy and organ transplantation contexts show short-fragment enrichment with amplitude changes but entropy changes are not increased in non-tumor scenarios
- dd-cfDNA analyses show differences in amplitude but not entropy between high vs low donor-derived DNA groups

QC result: Pass.

362: D614G Reshapes Spike Allostery and Speeds RBD Opening

Gustavo Barra — Sat, 09 May 2026 18:52:18 +0000

Kearns FL et al., PNAS - Simulations and HDXMS reveal how the D614G substitution alters internal communication in SARS-CoV-2 spike, enabling faster receptor-binding-domain opening through newly engaged allosteric pathways. Key terms: D614G, SARS-CoV-2 spike, RBD opening, allostery, weighted ensemble simulations.

Study Highlights:
Weighted ensemble simulations of Ancestral, Delta, and Omicron BA.1 spikes show distinct RBD opening landscapes and identify two S1 linkers (N2R and a previously underappreciated antiparallel R2N) that connect the NTD to the RBD. In the Ancestral spike a D614–K854 salt bridge constrains the R2N and must break before RBD opening; D614G abolishes that constraint, increasing local flexibility and enabling communication through both linkers. Delta and Omicron BA.1, both carrying D614G, open faster and use balanced N2R/R2N signaling; Omicron also forms a K856–D568 salt bridge and can adopt a unique “peel” conformation. Hydrogen–deuterium exchange mass spectrometry on VLPs confirms altered dynamics around the 614-proximal region consistent with the simulations.

Conclusion:
Ablation of the D614–K854 salt bridge by D614G relieves local frustration, opens an additional allosteric lane via the R2N linker alongside N2R, and accelerates RBD opening—providing a mechanistic link between the D614G substitution and increased infectivity; Omicron BA.1 further tunes this network with compensatory interactions.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
D614G reshapes allosteric networks and opening mechanisms of SARS - CoV - 2 spikes

First author:
Kearns FL

Journal:
PNAS

DOI:
10.1073/pnas.2504793123

Reference:
Kearns FL, Bogetti AT, Calvó-Tusell C, et al. D614G reshapes allosteric networks and opening mechanisms of SARS-CoV-2 spikes. PNAS. 2026;123(19):e2504793123. doi:10.1073/pnas.2504793123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/d614g-reshapes-allosteric-networks

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-05-09.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the spoken content for alignment with the PNAS article's core findings: D614G reshapes spike allostery, dual N2R/R2N pathways, D614-K854 salt-bridge dynamics, Delta/Omicron opening differences, Omicron peel state, and HDXMS corroboration; plus methodological details (WE/MA binning, glycans, and limitations).
- transcript topics: D614G impact on RBD opening dynamics; Weighted Ensemble simulations (WE) and minimal adaptive binning (MAB); N2R and R2N flexible linkers as allosteric pathways; D614-K854 salt bridge role and congestion; Variant-specific opening pathways: Delta and Omicron; Omicron BA.1 peel state and K856-D568 salt bridge

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- D614G abolishes the D614-K854 salt bridge, increasing local flexibility and accelerating RBD opening via dual N2R and R2N linkers
- Delta and Omicron spikes open faster than ancestral and utilize both N2R and R2N pathways
- Ancestral spike relies mainly on the N2R linker; Delta and Omicron use both linkers for RBD opening
- Omicron BA.1 adopts a peel state with a new K856-D568 salt bridge to restabilize FPPR and enable broader opening
- HDXMS on VLPs shows altered dynamics near the 614 region consistent with simulation predictions; peptides near D614G region demonstrate altered deuterium uptake
- WE simulations with minimal adaptive binning mapped RBD opening across variants; hundreds of microseconds of aggregated time over ~2 months on GPUs

QC result: Pass.

361: Chiral Inversion Mutagenesis Reveals Structured Hotspots in LCDs

Gustavo Barra — Fri, 08 May 2026 10:43:24 +0000

Beckner RL et al., PNAS - This episode examines a PNAS study using Chiral Inversion Mutagenesis (ChIM) to scan low-complexity domains (LCDs) of Emerin and neurofilament light chain (NEFL). Targeted L-to-D amino acid inversions reveal position-dependent, chirality-sensitive hotspots that control LCD self-association. Key terms: chiral inversion, low-complexity domains, Emerin, neurofilament light chain, synthetic protein chemistry.

Study Highlights:
The authors applied synthetic protein chemistry to introduce site-specific L-to-D Cα inversions (ChIM) in LCDs of Emerin (EMD) and NEFL. ChIM scans identified discrete enantioselective hotspots—EMD residues ~191–203 and NEFL residues ~22–41—where D substitutions strongly reduce self-association measured by GST pulldown and turbidity assays. Minimal inversions, including single D substitutions, can abrogate EMD self-association, while an all-D mirror-image C-terminal fragment restored activity, implicating backbone geometry and secondary-structure involvement. These results show that polypeptide homochirality and transient structure underpin certain LCD–LCD interactions.

Conclusion:
Cα stereochemistry is a determinant of LCD self-association at specific sequence hotspots, and ChIM provides a positional-resolution chemical approach to identify backbone-constrained elements that mediate oligomerization of disordered domains.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Chiral inversion mutagenesis identifies geometrically constrained residues within self - associating low - complexity domains

First author:
Beckner RL

Journal:
PNAS

DOI:
10.1073/pnas.2535888123

Reference:
Beckner RL, Kim L, Carter C, Walterscheid A, Liszczak G. Chiral inversion mutagenesis identifies geometrically constrained residues within self-associating low-complexity domains. Proc Natl Acad Sci U S A. 2026;123(19):e2535888123. doi:10.1073/pnas.2535888123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/chiral-inversion-lcd-hotspots-361

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-05-08.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the spoken sections describing: ChIM methodology; Emerin LCD hotspot mapping (188–201) with 3×Pro and 3×D scans; single-residue effects (1×D) and all-D mirror-image rescue; NEFL head domain hotspot (22–41) with 5×D scans; assay descriptions (GST pulldown, turbidity); cross-β/anti-selective interactions; drug-de
- transcript topics: Chiral inversion mutagenesis (ChIM) methodology; Emerin (EMD) LCD self-association hotspot mapping (188–201) with Pro/ D-inversions; NEFL head domain hotspot mapping (22–41) with 5×D inversions; Mutational scan results: 3×D, 1×D, 5×D variants and effects on pulldown/turbidity; Mirror-image (all-D) fragment rescue for Emerin; Assays: GST pulldown and turbidity measurements

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- ChIM identifies enantioselective interaction hotspots in LCD self-association
- Emerin hotspot localized to residues 188–201; 3×Pro insertions disrupt, 3×D inversions within hotspot abrogate pulldown
- Single 1×D inversion reduces turbidity by ~6.4-fold in Emerin
- All-D mirror-image C-terminal fragment restores Emerin LCD self-association
- NEFL head domain hotspot localized to residues 22–41; 5×D inversions yield ~9.1-fold and ~20-fold turbidity reductions (22–30 and 33–41 respectively)
- Outside NEFL hotspot, inversions do not disrupt self-association to the same extent

QC result: Pass.

360: An inverse correlation between structural linguistic and human genetic diversity

Gustavo Barra — Thu, 07 May 2026 10:40:34 +0000

Graff A et al., PNAS - A PNAS study linking global population-genetic data and structural linguistic features finds an inverse correlation: regions with lower genetic diversity show higher structural linguistic diversity, after controlling for geography, phylogeny, and environment. Key terms: linguistic diversity, population genetics, Wright's F, language contact, structural typology.

Study Highlights:
The authors merged global genomic samples (Wright’s F / homozygosity) with curated structural linguistic datasets and estimated local structural entropy per grid cell. Using Bayesian GAMMs that adjust for spatial, phylogenetic, environmental, and sampling confounds, they find that higher excess homozygosity (lower genetic diversity) predicts higher structural linguistic entropy. The genetic predictor outperforms other covariates and the effect is robust across grid resolutions and sensitivity checks, though it varies by region and by specific linguistic features. The pattern supports a model where isolation promotes linguistic diversification while contact and admixture promote homogenization.

Conclusion:
An inverse, regionally variable correlation between local human genetic diversity and structural linguistic diversity suggests isolation-driven hotspots are key windows into the flexibility and evolution of language structure.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
An inverse correlation between structural linguistic and human genetic diversity

First author:
Graff A

Journal:
PNAS

DOI:
10.1073/pnas.2526762123

Reference:
Graff A., Ringen E.J., Zakharko T., Stoneking M., Shimizu K.K., Bickel B., Barbieri C. An inverse correlation between structural linguistic and human genetic diversity. Proc. Natl. Acad. Sci. U.S.A. 2026;123(18):e2526762123. doi:10.1073/pnas.2526762123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/inverse-correlation-linguistic-genetic-diversity

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-05-07.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited sections describing inverse relationship between local genetic diversity and structural linguistic diversity, methods (F coefficient, entropy, geodesic hex grids), magnitude of effects, regional patterns, and study limitations; cross-checks with article content performed.
- transcript topics: Inverse relationship between genetic diversity and linguistic structural diversity; Genetic metric Wright's F and linguistic entropy (normalized Shannon entropy); Geodesic hex grid methodology and grid resolutions (500 km and 300 km); Regional variation and strongest signals (North-Central Asia, Southeast Asia); Feature-level impact and percent of features affected by genetic diversity; Limitations: correlation vs causation and blind spots of genetic data

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 5
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Inverse correlation between local genetic diversity (F) and local structural linguistic diversity (entropy) after adjusting for geography, phylogeny, environment
- F coefficient reflects excess homozygosity, proxy for historical isolation; high F indicates low genetic diversity
- Structural linguistic diversity quantified via normalized Shannon entropy across 333 features in 4,257 languages (TLI dataset) with cross-check in GBI (196 features, 2,467 language
- Two grid resolutions used: 500 km and 300 km; analyses include jittered coordinates as sensitivity checks
- Genetic predictor emerges as strongest correlates of linguistic diversity, outperforming environment and population density in main models
- Magnitude: approximately 2.3% increase in entropy per SD increase in F (500 km grid); about 2.1% in the finer grid (300 km)

QC result: Pass.

359: Ultrapotent PDCoV Miniprotein MB11

Gustavo Barra — Wed, 06 May 2026 05:58:33 +0000

Avery NG et al., PNAS - This episode covers a PNAS study reporting the de novo design of miniprotein inhibitors targeting porcine deltacoronavirus (PDCoV). The lead minibinder, MB11, binds the PDCoV RBD with picomolar affinity, broadly neutralizes diverse deltacoronaviruses, and resists multiple biochemical stresses. Key terms: Porcine deltacoronavirus, miniprotein inhibitor, MB11, protein design, neutralization.

Study Highlights:
Researchers used computational design (BindCraft and AlphaFold3) to generate miniprotein inhibitors targeting the PDCoV receptor-binding domain and screened candidates by BLI and pseudovirus neutralization. MB11 binds the PDCoV RBD with KD ~155 pM and neutralizes PDCoV and several distantly related DCoVs with superior potency to known antibodies. Cryo-EM shows MB11 occludes receptor-binding loops and sterically blocks APN engagement, explaining broad neutralization. Deep mutational scanning indicates a high barrier to escape and biochemical tests show MB11 retains function after high temperature and low pH exposure but is susceptible to pepsin.

Conclusion:
MB11 is a promising preclinical PDCoV inhibitor combining ultrapotent, broad neutralization, mechanistic receptor blockade, and favorable stability, supporting further development for pandemic preparedness.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Computational design of an ultrapotent deltacoronavirus miniprotein inhibitor

First author:
Avery NG

Journal:
PNAS

DOI:
10.1073/pnas.2533456123

Reference:
Avery NG, Yoshiyama CN, Taylor AL, Park Y-J, Asarnow D, Perruzza L, Brown JT, Corti D, Benigni F, Starr TN, Veesler D. Computational design of an ultrapotent deltacoronavirus miniprotein inhibitor. PNAS. 2026;123:e2533456123. doi:10.1073/pnas.2533456123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/mb11-pdcoronavirus-minibinder

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-05-06.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the sections covering MB11 design (BindCraft/AF3), binding measurements (BLI), neutralization assays (PDCoV and related DCoVs), cryo-EM structural validation, deep mutational scanning escape analysis, biophysical stability tests (heat/acid/enzymes), and delivery/manufacturing implications discussed.
- transcript topics: Computational minibinder design (BindCraft and AlphaFold3); Biolayer interferometry binding screening; Pseudovirus neutralization assays and breadth across DCoVs; Cryo-EM structure and mechanism of entry inhibition; Deep mutational scanning and viral escape barriers; Biophysical stability under heat, low pH, and proteases

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- MB11 has KD ≈ 155 pM to PDCoV RBD (binds with high affinity).
- MB11 neutralizes PDCoV pseudovirus with IC50 ≈ 216 pM.
- MB11 shows broad neutralization across DCoVs, including SparrowCoVISU42824 (IC50 ≈ 14 pM) and MuniaCoVHKU13 (IC50 ≈ 152 nM).
- Cryo-EM reveals MB11 wedges into PDCoV RBD receptor-binding loops, blocking APN engagement; structure at 2.8 Å resolution with AF3 predicted model within ~0.6 Å RMSD.
- Deep mutational scanning shows a high barrier to escape; only a few mutations (at residues such as Y394 and V395) can modestly affect binding without severely compromising APN affi
- MB11 remains functional after heating to 70 °C for 1 h and after exposure to pH 2.2; largely resistant to proteases (except pepsin) and not aggregated after stress.

QC result: Pass.

358: CHCHD4 and a Pediatric OXPHOS Collapse

Gustavo Barra — Tue, 05 May 2026 08:54:13 +0000

Mantecon M et al., Human Genetics and Genomics Advances - This episode reviews a brief communication reporting a pediatric patient with biallelic CHCHD4 variants who presented with severe neurological regression and early death. Functional studies in patient fibroblasts show decreased CHCHD4 protein, marked assembly defects of mitochondrial complexes I and IV, and broad downregulation of electron transport and complex I biogenesis. Lentiviral expression of wild-type CHCHD4 restored OXPHOS proteins and assembly, linking CHCHD4 deficiency to human mitochondrial disease. Key terms: CHCHD4, mitochondrial disease, OXPHOS, complex I, protein import.

Study Highlights:
A single infant carried a paternal c.5C>T (p.Ser2Phe) CHCHD4 variant and a maternal deletion encompassing CHCHD4, resulting in markedly reduced CHCHD4 protein and severe lactic acidosis with neurological regression. Fibroblast analyses revealed decreased complex I and IV subunits, assembly defects on BN-PAGE, and widespread downregulation of mitochondrial proteins by proteomics, with respiratory electron transport and complex I biogenesis identified as the main dysregulated pathways. Lentiviral overexpression of wild-type CHCHD4 in patient cells restored CHCHD4 levels, rescued complex I and IV protein abundance and assembly, and reversed many proteomic changes, supporting causality.

Conclusion:
Biallelic CHCHD4 deficiency causes a severe early-onset mitochondrial disease by impairing mitochondrial protein import and assembly of complexes I and IV; restoration of CHCHD4 rescues the molecular defects. Additional cases are needed to define the clinical spectrum and the functional impact of specific variants.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Biallelic variants in CHCHD4 are associated with combined OXPHOS defect leading to mitochondrial disease

First author:
Mantecon M

Journal:
Human Genetics and Genomics Advances

DOI:
10.1016/j.xhgg.2026.100615

Reference:
Mantecon M, Chhuon C, Roger K, et al. Biallelic variants in CHCHD4 are associated with combined OXPHOS defect leading to mitochondrial disease. Human Genetics and Genomics Advances. 2026;7:100615. doi:10.1016/j.xhgg.2026.100615

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/biallelic-chchd4-oxphos-defect

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-05-05.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the sections describing CHCHD4 function in the MIA pathway, the pediatric case with biallelic CHCHD4 variants, AlphaFold structural predictions for Ser2Phe, lentiviral complementation rescuing OXPHOS defects, and the proteomics results including selective vulnerability and clinical implications.
- transcript topics: MIA pathway and CHCHD4 function in mitochondrial protein import; Genetic case and inheritance pattern (p.Ser2Phe with maternal CHCHD4 deletion); AlphaFold structural prediction of Ser2Phe destabilizing CHCHD4; Functional complementation rescue with WT CHCHD4 in patient fibroblasts; Proteomics results showing OXPHOS defects and selective vulnerability; Clinical implications: CHCHD4 deficiency as a novel cause of mitochondrial disease

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- CHCHD4 is a component of the mitochondrial import and assembly (MIA) pathway that imports small cysteine-containing substrates and its deficiency impairs import and assembly of oxi
- Subject carried biallelic CHCHD4 variants: paternal Ser2Phe and a maternal CHCHD4 deletion; subject fibroblasts show reduced CHCHD4 and defects in OXPHOS protein levels and assembl
- AlphaFold predicted that Ser2Phe destabilizes CHCHD4 by disrupting a hydrogen-bond zipper near a beta-hairpin, explaining loss of function.
- Functional complementation with wild-type CHCHD4 via lentiviral expression rescues CHCHD4 levels and restores complex I and IV protein abundance and assembly in subject-derived cel
- Proteomics shows broad downregulation of mitochondrial proteins with CHCHD4 deficiency; rescue of CHCHD4 restores many affected proteins; iron-sulfur cluster export pathways largel
- CHCHD4 deficiency is identified as a novel cause of severe mitochondrial disease in humans; the study is limited by a single-case design and calls for additional cases to define na

QC result: Pass.

356: Recessive Coding Associations Across Six Biobanks

Gustavo Barra — Sun, 03 May 2026 22:44:51 +0000

Lassen F et al., The American Journal of Human Genetics - Meta-analysis of up to 948,690 exome- or whole-genome-sequenced individuals across six biobanks used statistical phasing to infer compound-heterozygous genotypes, increasing detectable bi-allelic damaging genotypes by 19% and identifying 58 significant gene-trait associations, 17 of which show stronger recessive effects. Key terms: recessive genetics, compound heterozygous, biobank meta-analysis, loss-of-function, statistical phasing.

Study Highlights:
The study combined data from UKB, All of Us, 100kGP, Genes & Health, BioMe, and BBJ totaling 948,690 samples and phased rare variants to detect compound-heterozygous genotypes. Phasing increased the number of bi-allelic damaging genotypes by 19% and identified 5,563 genes with bi-allelic pLoF genotypes. Gene-based recessive testing across 41 traits found 58 significant associations after meta-analysis and Cauchy combination, with 17 instances showing stronger recessive than additive effects, including HBB with heart failure and LECT2 with height. The federated, cross-biobank approach improved power and highlighted the value of diverse ancestries for discovering recessive effects.

Conclusion:
Federated meta-analysis across multiple biobanks combined with statistical phasing substantially increases discovery of rare recessive gene-trait associations and expands the catalog of human gene knockouts, demonstrating the importance of phasing and diverse cohorts for recessive-effect discovery.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Meta-analysis across six global biobanks identifies recessive coding associations with complex traits and diseases

First author:
Lassen F

Journal:
The American Journal of Human Genetics

DOI:
10.1016/j.ajhg.2026.04.005

Reference:
Lassen F.H. et al., 2026. Meta-analysis across six global biobanks identifies recessive coding associations with complex traits and diseases. The American Journal of Human Genetics 113, 1–17. https://doi.org/10.1016/j.ajhg.2026.04.005

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/recessive-coding-associations-six-biobanks

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-05-03.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited transcript sections describing: the role of statistical phasing to identify compound-heterozygous genotypes, the scale across six biobanks (~950k individuals), the rise in bi-allelic genotypes, and key recessive gene–trait associations (HBB, LECT2, ENSG00000267561, PYGM, ODAD1), plus pleiotropy and conditional
- transcript topics: Introduction to human knockouts and biobank-scale data; Compound heterozygosity and the need for phasing; Statistical phasing across six biobanks and study scale; Gene-based recessive associations across 41 traits; Notable associations: HBB with heart failure and lipids; LECT2 with height; ENSG00000267561 with height; BTNL9 association with HDL-C and triglycerides

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- PHASED approach increased bi-allelic damaging genotypes by 19% (compound-heterozygous and homozygous) across biobanks
- Identified 5,563 genes harboring bi-allelic genotypes; 1,767 additional genes beyond previous studies; total 8,925 unique genes when accounting for overlaps
- CH variants increased testable genes by 8.9% to 1,253 genes (from 1,151)
- 58 significant gene–trait associations identified; 17 likely recessive (based on comparing recessive vs additive signals)
- Notable recessive associations include HBB with heart failure and lipid traits; LECT2 with height; ENSG00000267561 with height; PYGM with AST; ODAD1 with COPD
- Ancestry-diversity contribution: 1,371 of the new knockouts found in non-European ancestries, concentrated in SAS cohorts

QC result: Pass.

355: Influenza D replicates in the human airway — zoonotic risk

Gustavo Barra — Sun, 03 May 2026 22:44:40 +0000

Sanders CG et al et al., PNAS - Surveillance-derived influenza D virus (IDV) isolates were tested across cell lines, primary airway cultures, and precision-cut lung slices to assess human compatibility. IDV replicated to high titers in human respiratory models while eliciting muted interferon responses, highlighting a potential zoonotic threat and the need for enhanced surveillance. Key terms: influenza D virus, zoonosis, human airway, interferon evasion, surveillance.

Study Highlights:
A panel of six genetically diverse IDV isolates replicated efficiently in MDCK and A549 cell lines, primary well-differentiated human bronchial epithelial cultures, porcine airway cultures, and precision-cut lung slices. IDV induced markedly reduced IRF activation and lower IFN-λ1 and ISG expression compared to human influenza A virus, indicating limited innate immune sensing. Pretreatment with IFN-β potently restricted IDV replication, showing the virus is sensitive to an established antiviral state. Active surveillance at US swine exhibitions recovered multiple genetically distinct IDV strains spanning several clades.

Conclusion:
IDV readily infects and replicates in human respiratory tissues while limiting innate sensing, supporting intensified surveillance and mechanistic studies to evaluate its zoonotic and pandemic potential.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Efficient replication of influenza D virus in the human airway underscores zoonotic potential

First author:
Sanders CG et al

Journal:
PNAS

DOI:
10.1073/pnas.2530325123

Reference:
Sanders CG et al., Efficient replication of influenza D virus in the human airway underscores zoonotic potential. PNAS (2026) Vol. 123 No. 17 e2530325123. doi:10.1073/pnas.2530325123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/influenza-d-human-airway-zoonotic-potential

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-05-03.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Substantively audited the transcript sections describing field surveillance, in vitro and tissue-level replication in human/porcine models, innate immune responses, receptor usage, and zoonotic implications as reported in the canonical article.
- transcript topics: Field surveillance and isolation of IDV from exhibition swine; IDV replication in MDCK cells and A549 cells; Primary human and porcine airway epithelial cultures (ALI); Precision-cut lung slices (PCLS) and tissue-level replication; Innate immune sensing and interferon responses (IRF, IFN-λ1, ISGs); Interferon-β pretreatment and antiviral state

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- IDV replicates to high titers in MDCK cells and in immortalized human lung cells (A549).
- IDV replicates efficiently in primary well-differentiated human airway epithelial cultures (ALI) and in porcine ALI cultures, with comparable replication kinetics across species.
- IDV replicates efficiently in human and swine precision-cut lung slices (PCLS).
- IDV elicits markedly weaker interferon signaling and lower IFN-λ1 and ISG induction compared with IAV.
- IDV replication is potently restricted by preactivation of antiviral state with IFN-β.
- Field surveillance at 422 swine exhibitions recovered three genetically distinct IDV strains from swine isolates (panel of six isolates used in downstream analyses).

QC result: Pass.

354: How Cohesin Acetylation and ATPase Shape Chromatin Loops and Cohesion

Gustavo Barra — Thu, 30 Apr 2026 06:30:58 +0000

Costantino L et al., PNAS - Costantino et al. dissect how Eco1-mediated acetylation of Smc3 (K112, K113) and cohesin ATPase activity separately regulate chromatin loop size, loop positioning, and sister chromatid tethering in budding yeast using Micro-C XL, ChIP, and biochemical ATPase assays. Key terms: cohesin, acetylation, ATPase, chromatin loops, sister chromatid cohesion.

Study Highlights:
Using a panel of budding yeast mutants, the authors show that acetylation of either Smc3 K112 or K113 is sufficient to produce positioned chromatin loops, while loss of both (Eco1 depletion) leads to expanded, unpositioned loops despite normal cohesin binding. K113 acetylation is required for sister chromatid cohesion (tethering), but cohesion-defective K113R mutants still form positioned loops, indicating looping can occur without tethering. K112 acetyl-mimic reduces loader-stimulated ATPase yet retains wild-type loop architecture, whereas hyper-ATPase mutants convert random loops into more positioned loops. The DE (low-ATPase) mutant produces long, unpositioned loops despite normal cohesin binding and Pds5 recruitment, indicating separable mechanisms downstream of acetylation and Pds5.

Conclusion:
Acetylation and ATPase activity separately tune cohesin's functions: acetylation at Smc3 K112/K113 helps position loops and control ATPase responsiveness, K113 acetylation is essential for tethering, and ATPase level biases cohesin toward random versus positioned loops, supporting active loop extrusion as the primary loop-forming mechanism.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Cohesin acetylation and ATPase activity control cohesion and loop architecture through distinct mechanisms

First author:
Costantino L

Journal:
PNAS

DOI:
10.1073/pnas.2531218123

Reference:
Costantino L, Ye T, Boardman K, Xiang S, Luo J, Mu Y, Ma W, Koshland D. Cohesin acetylation and ATPase activity control cohesion and loop architecture through distinct mechanisms. PNAS. 2026;123(17):e2531218123. doi:10.1073/pnas.2531218123.

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/cohesin-acetylation-atpase-loop-architecture

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-04-30.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript sections describing cohesin functions (loop extrusion and tethering), Eco1-mediated Smc3 acetylation at K112/K113, ATPase regulation by Scc2/Scc4, mutations (K112R, K113R, K112Q, K113Q, DE, TI), Micro-C XL method and CARs, Pds5 involvement, and the active loop extrusion model versus loop capture.
- transcript topics: Cohesin functions: loop extrusion and sister chromatid tethering; Smc3 K112/K113 acetylation and Eco1; ATPase regulation by loader Scc2/Scc4 and acetylation; Mutant analyses: K112R, K113R, K112Q, K113Q, ECO1-AID, TI, DE; Micro-C XL methodology and CARs/positioned loops; Pds5 binding and loop regulation

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Either K112 or K113 acetylation suffices to position loops; Eco1 depletion (both acetylations removed) leads to loop expansion and loss of positioned loops
- K113 acetylation is essential for sister chromatid cohesion; K113R mutants are cohesion-defective but can form positioned loops
- K112 acetylation reduces loader-stimulated ATPase; K112Q partially reduces ATPase; K113Q strongly reduces/abolishes loader stimulation
- Hyper-ATPase mutants (TI) reduce random loops and increase positioned loops; DE mutant (low ATPase) yields long, unpositioned loops despite cohesin binding
- DE mutant shows cohesin binding and Pds5 recruitment similar to wild type, suggesting defects are downstream of Pds5 recruitment
- Three distinct ATPase states are proposed: unacetylated (fully inducible/loop-extruding), K112-acetylated (partially inducible), K113-acetylated (non-inducible/cohesion-promoting)

QC result: Pass.

353: Masculinization Reverses Sex Differences in Fertility

Gustavo Barra — Thu, 30 Apr 2026 06:23:57 +0000

Schubert HA et al., PNAS - This episode reviews a global analysis showing that shifts in population sex composition have reversed historical sex gaps in fertility. Using UN World Population Prospects 2024 data and regression and standardization methods, the authors estimate male total fertility rates and project widening differences through 2100 driven by masculinized reproductive-age populations. Key terms: male fertility, sex ratio, total fertility rate, sex-selective abortion, population structure.

Study Highlights:
The authors estimate male and female total fertility rates using UN WPP2024 data combined with a regression-based model and demographic standardization. They identify a global crossover in 2024 when female TFRs first exceeded male TFRs and project growing disparities through 2100, especially in East Asia. Key drivers are higher sex ratios at birth, declining mortality, and a narrowing male–female mortality gap, with sex-selective abortion amplifying effects in some countries. The analysis highlights social consequences such as rising male childlessness and offers policy recommendations to mitigate sex imbalances.

Conclusion:
Masculinization of reproductive-age populations has flipped historical fertility patterns so that female TFRs now often exceed male TFRs, a gap expected to widen in many regions and to carry social and policy implications related to childlessness and partnership markets.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Masculinization of populations reverses sex differences in fertility

First author:
Schubert HA

Journal:
PNAS

DOI:
10.1073/pnas.2533317123

Reference:
Schubert HA, Spoorenberg T, Dudel C, Skirbekk VF. Masculinization of populations reverses sex differences in fertility. Proc Natl Acad Sci U S A. 2026;123:e2533317123. doi:10.1073/pnas.2533317123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/353-masculinization-populations-fertility

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-04-30.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript sections describing historical sex differences in fertility, the 2024 crossover, drivers (birth sex ratio, mortality decline, sex-selective abortion), the age-gap Model 3 estimation approach, regional variations (East Asia vs Sub-Saharan Africa), war shocks, and policy implications.
- transcript topics: Historical fertility gender gaps and denominator effects; Birth sex ratio and sex-selective abortion; Mortality decline and sex mortality gap; Model 3 age-gap estimation of male TFR; Global crossover year 2024 and 2100 projections; Regional variations: East Asia vs Sub-Saharan Africa

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Global crossover year: 2024
- 2100 projection: <10% of countries have higher TFRm
- Three drivers of masculinization: birth sex ratio, mortality decline...

Chapters

(00:00:12) - The feminization of the population
(00:05:45) - The demographic structure of human populations
(00:07:15) - The Real Story Behind Global Fertility
(00:12:47) - Maternal mortality in the US and Europe
(00:13:19) - How Does War Affect Male Fertility?
(00:17:27) - What Actually Happens to Men When They're Out of the Marriage
(00:21:46) - The Future of Families Is Shaping
(00:23:42) - A Place to Be After the Crossover

352: Interspecies control of E. coli growth in human gut microbiomes

Gustavo Barra — Mon, 27 Apr 2026 06:29:21 +0000

Boumasmoud M et al., PNAS - Reciprocal transplant experiments in anaerobic microcosms show that resident human gut microbiome context alters growth of introduced Escherichia coli strains and that microbially mediated acidification, driven by a Clostridium butyricum strain, can reproducibly suppress E. coli and reshape community fermentation profiles. Key terms: gut microbiome, Escherichia coli, interspecies interaction, acidification, Clostridium butyricum.

Study Highlights:
Using six human stool-derived microbiome samples and six resident E. coli isolates in replicated anaerobic microcosms, the authors measured strain-level and species-level growth across 36 strain-by-microbiome combinations. Growth performance of E. coli strains varied with microbiome context and was constrained by intraspecific competition setting a finite E. coli abundance per microbiome. One microbiome (M6) acidified during cultivation, inhibiting E. coli growth; a Clostridium butyricum isolate from M6 reproduced this acidification when transplanted into other samples. Addition of C. butyricum lowered pH, increased butyrate and decreased acetate/lactate, suppressed E. coli and altered overall community composition.

Conclusion:
Interindividual gut-microbiome variation causes variable ecological interactions that affect colonization by incoming strains, and a single transferable taxon (C. butyricum) can act as an ecological control point by driving acidification and reshaping community growth and metabolites.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Interspecies interaction controls Escherichia coli growth in human gut microbiome samples

First author:
Boumasmoud M

Journal:
PNAS

DOI:
10.1073/pnas.2527793123

Reference:
Boumasmoud M., León-Sampedro R., Beusch V., Benza F., Arnoldini M., Hall A.R. Interspecies interaction controls Escherichia coli growth in human gut microbiome samples. PNAS. 2026;123(17):e2527793123. doi:10.1073/pnas.2527793123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/interspecies-ecoli-growth-microbiome

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-04-27.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript's discussion of experimental design, key results (strain performance variation, acidification, keystone C. butyricum), and ecological implications; compared to the original article's reported methods, results, and interpretations.
- transcript topics: Experimental design: reciprocal transplant in anaerobic microcosms (M2–M7) with six E. coli strains; Strain-level and species-level growth variation across microbiome samples; Intraspecific competition and microbiome-specific finite E. coli abundance; Acidification as a driver of growth suppression; pH measurements; Clostridium butyricum as a keystone species driving acidification and community shifts; Transplantation of C. butyricum into other microbiomes; effects on butyrate, acetate, lactate

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Six donor microbiome samples (M2–M7) and six focal E. coli strains (S2–S7) tested in 36 strain–microbiome combinations; growth varied by microbiome context
- No average home-field adaptation detected; rank order of strains largely consistent across microbiomes with S3 and S7 often most abundant
- Microbiome sample M6 acidified during incubation (pH ~5.4) and suppressed E. coli growth; neutralization restored growth
- A Clostridium butyricum strain isolated from M6 acidified medium and, when transplanted into other microbiomes, reduced pH and altered fermentation products (increased butyrate, de
- Butyricum transplantation reduced E. coli and total bacterial growth and reshaped community composition
- Butyrate production increased by 14.8 mM on average after C. butyricum inoculation; acetate decreased by ~8.08 mM and lactate by ~6.45 mM

QC result: Pass.

351: When Selection Survives Admixture: Hard Sweeps in Ancient Eurasians

Gustavo Barra — Sun, 26 Apr 2026 10:58:26 +0000

Harris M et al., Proceedings of the National Academy of Sciences (PNAS) - This episode examines a PNAS study that uses a domain-adaptive neural network to detect and classify selective sweeps in over 800 ancient and modern Eurasian genomes spanning ~7,000 years. The work recovers known targets (HLA, LCT, OCA2/HERC2, KITLG), reports 32 novel ancient sweep candidates, finds hard sweeps predominate, and shows 14 sweeps persisted across a major admixture event, highlighting resilience of certain adaptations. Key terms: ancient DNA, selective sweeps, domain-adaptive neural network, hard sweeps, admixture.

Study Highlights:
The authors trained a domain-adaptive neural network on simulated and ancient DNA to distinguish hard sweeps, soft sweeps, and neutrality across 708 ancient and 99 modern Eurasian genomes. The DANN outperformed standard CNNs under demographic and missing-data misspecification and detected 48 ancient sweeps, including 16 overlapping prior reports and 32 novel candidates. All identified sweeps were classified as hard and, after accounting for misclassification rates, the majority remain best explained by hard sweeps. Fourteen sweeps at genes involved in neuronal, reproductive, pigmentation, and signaling functions persisted across a major admixture event, often retaining the same high-frequency haplotype.

Conclusion:
Domain-adaptive deep learning improves detection of selective sweeps in degraded ancient genomes; hard sweeps were the dominant mode of adaptation in these ancient Eurasian samples and several selective events persisted despite strong admixture, pointing to sustained functional importance of particular loci.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
The persistence and loss of hard selective sweeps amid admixture in ancient Eurasians

First author:
Harris M

Journal:
Proceedings of the National Academy of Sciences (PNAS)

DOI:
10.1073/pnas.2528672123

Reference:
Harris M., Mo Z., Siepel A., Garud N.R. The persistence and loss of hard selective sweeps amid admixture in ancient Eurasians. Proc. Natl. Acad. Sci. U.S.A. 2026;123(17):e2528672123. doi:10.1073/pnas.2528672123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/hard-sweeps-admixture-ancient-eurasians

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-04-26.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript sections describing the DANN method (domain adaptation, GRL, haplotype image inputs), the major results (counts of ancient/modern sweeps, hard sweeps, persistence across admixture), and the highlighted loci (HLA, LCT, OCA2/HERC2, KITLG), plus the discussion of admixture timing (~4.5 kya) and impl
- transcript topics: Domain-adaptive neural networks (DANN) and gradient reversal layer; Ancient DNA data quality and missing data; Hard vs soft sweeps definitions; Sweep detection results (ancient vs modern) and total counts; Admixture event around 4.5 kya and sweep persistence; Loci of interest: HLA, LCT, OCA2/HERC2, KITLG

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 5
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- 708 ancient Eurasian genomes analyzed; 99 modern European genomes used for comparison
- Ancient sweeps detected: 48; modern sweeps detected: 28; total across datasets: 58
- All identified sweeps classified as hard sweeps; estimated hard sweeps exceed soft sweeps (80+%)
- 14 sweeps persisted across a major admixture event (~4.5 thousand years ago)
- Loci repeatedly highlighted among sweeps include HLA, LCT, OCA2/HERC2, KITLG

QC result: Pass.

350: OPA1 A8S in Rhesus Macaques Models Autosomal Dominant Optic Atrophy

Gustavo Barra — Sat, 25 Apr 2026 19:21:26 +0000

Jaggers TN et al et al., PNAS - A spontaneous OPA1 A8S missense mutation in rhesus macaques produces retinal ganglion cell loss, RNFL thinning, optic nerve atrophy, OPA1 mislocalization, and mitochondrial abnormalities, creating a nonhuman primate model that mirrors human autosomal dominant optic atrophy. Key terms: OPA1, autosomal dominant optic atrophy, rhesus macaque, retinal ganglion cell, mitochondria.

Study Highlights:
The authors identified an OPA1 NM_015560.2:c.22G>T (p.ala8ser, A8S) variant segregating dominantly in a rhesus colony. Heterozygous macaques showed significant peripapillary RNFL thinning, temporal optic nerve head pallor, and reduced PERG amplitudes consistent with RGC dysfunction. Histology and TEM revealed RGC loss, reduced axonal mitochondrial density, dysmorphic mitochondria, myelin disruption, and OPA1 mislocalization in RNFL axons. The model displays phenotypic variability similar to human ADOA and supports use for preclinical testing of mitochondrial- and gene-targeted therapies.

Conclusion:
A spontaneous OPA1 A8S mutation in rhesus macaques recapitulates key structural, functional, and ultrastructural features of human ADOA, providing a translational NHP model for testing therapies.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Rhesus macaques with an OPA1 mutation demonstrate features of autosomal dominant optic atrophy

First author:
Jaggers TN et al

Journal:
PNAS

DOI:
10.1073/pnas.2509165123

Reference:
Jaggers TN et al., Rhesus macaques with an OPA1 mutation demonstrate features of autosomal dominant optic atrophy. PNAS. 2026;123:e2509165123. https://doi.org/10.1073/pnas.2509165123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/350-opa1-rhesus-adoa

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-04-25.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Substantive audit of the transcript sections describing the OPA1 A8S mutation, heterozygous phenotype (RNFL thinning, ONH pallor, PERG deficits), ultrastructural mitochondrial defects and OPA1 mislocalization, homozygous cases, and translational therapy implications.
- transcript topics: OPA1 A8S mutation and spontaneous nonhuman primate model; Autosomal dominant optic atrophy (ADOA) in rhesus macaques; RNFL thinning and optic nerve head pallor; PERG dysfunction in OPA1 heterozygotes; Mitochondrial abnormalities and OPA1 mislocalization; TEM findings: dysmorphic mitochondria and axon loss

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 5
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- OPA1 A8S missense mutation identified in rhesus macaques in CNPRC colony
- Mutation is dominant and linked to autosomal dominant inheritance pattern
- Heterozygotes show RNFL thinning and temporal ONH pallor; PERG amplitudes reduced
- OPA1 mislocalization and reduced axonal mitochondrial density observed in retina
- Homozygous OPA1 macaques identified; survi...

Chapters

(00:00:12) - The secret to a cure for blindness
(00:05:27) - Human blindness: The mutation that causes
(00:11:33) - Macaque blindness: algorithmic analysis fails
(00:17:47) - These macaques have suddenly cleared the pipeline for a sight cure
(00:20:37) - Bring the Brass Lights Back to the Ear

349: Oxidized rNTPs and Transcription Fidelity: How 8‑oxo‑rGTP Embeds RNA Damage

Gustavo Barra — Fri, 24 Apr 2026 09:58:31 +0000

Hou P et al., PNAS - This study combines kinetic assays and X‑ray crystallography to show how 8‑oxo‑guanosine triphosphate (8‑oxo‑rGTP) is incorporated by RNA polymerase II and how its pairing geometry with template bases (dC vs dA) differentially alters incorporation efficiency, extension, and proofreading, thereby introducing transcription‑coupled RNA damage. Key terms: RNA damage, 8-oxo-rGTP, RNA polymerase II, transcription fidelity, oxidative stress.

Study Highlights:
Pol II incorporates 8‑oxo‑rGTP efficiently opposite dC with kinetics comparable to GTP, whereas incorporation opposite dA is much slower but ~150‑fold more efficient than misincorporation of undamaged rGTP. Extension proceeds rapidly from a 3′‑r8OG:dC pair but is markedly slower from a 3′‑r8OG:dA pair. TFIIS‑stimulated proofreading cleaves r8OG:dC robustly but r8OG:dA is resistant to backtracking and cleavage. Crystal structures reveal 8‑oxo‑rG adopts anti Watson–Crick geometry with dC in the A‑site but flips to syn Hoogsteen geometry with dA, where an interaction with Rpb2 E529 stabilizes a pretranslocation state.

Conclusion:
Oxidation of the nucleotide pool can directly undermine Pol II fidelity by enabling efficient incorporation and differential handling of 8‑oxo‑rGTP, producing transcription‑coupled RNA damage with potential consequences for RNA processing, translation, and disease.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Structural basis of transcription -coupled RNA damage by incorporation of oxidized ribonucleotides

First author:
Hou P

Journal:
PNAS

DOI:
10.1073/pnas.2602266123

Reference:
Hou P, Lee C, Chong J, Oh J, Wang D. Structural basis of transcription-coupled RNA damage by incorporation of oxidized ribonucleotides. PNAS. 2026;123(16):e2602266123. doi:10.1073/pnas.2602266123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/8oxo-rgpt-transcription-rna-damage

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-04-24.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited sections on background, kinetic experiments, structural determinations, proofreading, translocation mechanics, and disease relevance; aligned with the canonical article.
- transcript topics: Oxidative stress and oxidized ribonucleotides; 8-oxo-rGTP incorporation opposite dC and dA templates; Presteady-state kinetics and incorporation efficiency; Extension after 8-oxo-rGTP incorporation; TFIIS proofreading and backtracking with oxidized nucleotides; Structural basis: A-site anti conformation with dC; syn Hoogsteen with dA; E529 fork loop 2 interaction

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- 8-oxo-rGTP can be efficiently incorporated opposite dC, with efficiency comparable to GTP
- 8-oxo-rGTP opposite dA is misincorporated ~150-fold more efficiently than rGTP misincorporation
- Pol II extends more efficiently from 8-oxo-rG:dC than from 8-oxo-rG:dA
- TFIIS-stimulated cleavage occurs for 8-oxo-rGTP:dC (~70% cleavage after 30 minutes) but is limited for 8-oxo-rGTP:dA (<10%)
- 8-oxo-rGTP binds at the A-site opposite dC in anti conformation; opposite dA it adopts syn conformation forming Hoogsteen pairing
- Syn-8-oxo-rG:dA forms a hydrogen bond with Rpb2 E529 in fork loop 2, stabilizing a pretranslocation state and impeding translocation/backtracking

QC result: Pass.

348: v96: A 96-mutation plasma DNA test to track residual AML through transplant

Gustavo Barra — Tue, 21 Apr 2026 22:49:34 +0000

Wang Y et al et al., PNAS - This episode covers a PNAS study describing v96, a personalized plasma cell-free DNA assay that tracks up to 96 patient-specific mutations to sensitively quantify measurable residual disease (MRD) in AML patients before and after allogeneic hematopoietic cell transplantation. Key terms: cell-free DNA, measurable residual disease, acute myeloid leukemia, hematopoietic cell transplantation, duplex sequencing.

Study Highlights:
The personalized v96 assay detected residual leukemia in 100% of 30 AML patients at clinical remission, compared with 20% by flow cytometry. Plasma cfDNA was more informative and sensitive than bone marrow DNA and driver mutation assays, with 90% of patients positive at 2 months posttransplant. Higher pretransplant mutant molecule counts correlated with relapse risk, and leukemic burden typically fell only after immunosuppression was discontinued, consistent with a graft-versus-leukemia effect.

Conclusion:
A plasma-based multiplexed assay (v96) enables highly sensitive, noninvasive MRD monitoring in AML patients undergoing transplantation and may inform timing of immunosuppression and posttransplant interventions, though larger studies are needed to confirm clinical utility.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
A plasma - based DNA test for quantification of disease burden in acute myeloid leukemia patients undergoing bone marrow transplantation

First author:
Wang Y et al

Journal:
PNAS

DOI:
10.1073/pnas.2537987123

Reference:
Wang Y et al., A plasma-based DNA test for quantification of disease burden in acute myeloid leukemia patients undergoing bone marrow transplantation. PNAS. 2026;123(16):e2537987123. doi:10.1073/pnas.2537987123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/v96-plasma-ctdna-aml-transplant

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-04-21.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript’s presentation of the v96 methodology, passenger vs driver mutations, plasma vs marrow MRD detection, relapse prediction, and posttransplant immunosuppression dynamics against the original article.
- transcript topics: v96 workflow and passenger mutation panel; duplex sequencing (SaferSeqS) and error suppression; plasma vs bone marrow cell-free DNA for MRD detection; driver vs passenger mutations for MRD assessment; predictive power for relapse (352-fold difference pre-transplant); graft-versus-leukemia (GvL) dynamics and immunosuppression

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 5
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- v96 assay tracks up to 96 leukemia-specific passenger mutations in plasma cfDNA and detects residual leukemia in all patients at complete remission (CR) by v96, vs 20% by flow cyto
- plasma cfDNA mutant-allele fractions (MAF) are higher than bone marrow DNA (2.9% vs 0.42%) at CR
- pre-transplant plasma mutant molecule counts are 352-fold higher in patients who relapse compared with those who do not relapse
- post-transplant residual disease declines more rapidly after immunosuppressive therapy is discontinued, indicating graft-versus-leukemia (GvL) activity
- v96 detects MRD in 100% of patients prior to transplant, whereas driver mutations detected by SaferSeqS are found in about 48% (10/21) at the same time point; at 2 months posttrans

QC result: Pass.

347: Diffusive spreading across dynamic mitochondrial network architectures

Gustavo Barra — Sun, 19 Apr 2026 12:25:57 +0000

Holta KB et al., Proceedings of the National Academy of Sciences (PNAS) - This episode explains a quantitative framework for diffusion on spatially embedded dynamic mitochondrial networks. The study combines analytic theory, agent-based simulations, and live-cell imaging to show how connectivity, fusion/fission, and mobility set biomolecular mixing on mitochondrial populations. Key terms: mitochondria, diffusion, intracellular transport, temporal networks, fusion-fission.

Study Highlights:
The authors develop an analytic and simulation framework for diffusive spreading on spatially embedded dynamic networks formed by mitochondrial fusion and fission. They identify a connectivity-driven transition from three-dimensional dispersion across transiently interacting clusters (social regime) to low-dimensional transport along largely stationary interconnected tubules (physical regime). The steady-state distribution is determined by competing timescales for cluster filling, encounter, fusion/fission, and material decay. Application to three human cell lines reveals cell-type variability in predicted spreading times, with hyperfused networks limited by intracluster diffusion and fragmented networks limited by encounters.

Conclusion:
Network connectivity and the balance of diffusion, encounter, and fusion/fission timescales quantitatively determine mitochondrial material homogenization, producing distinct scaling regimes with measurable predictions across cell types.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Diffusive spreading across dynamic mitochondrial network architectures

First author:
Holta KB

Journal:
Proceedings of the National Academy of Sciences (PNAS)

DOI:
10.1073/pnas.2523913123

Reference:
Holta KB, Zurita C, Teryoshin L, Lewis SC, Koslover EF. Diffusive spreading across dynamic mitochondrial network architectures. Proc Natl Acad Sci U S A. 2026;123(15):e2523913123. doi:10.1073/pnas.2523913123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/diffusive-spreading-mitochondrial-networks

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-04-19.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Substantive auditing of the transcript’s representation of the article’s core framework, regimes, timescales, cell-type predictions, modeling approach, and acknowledged limitations, with cross-checks against the original article text and the facts pack.
- transcript topics: Temporal networks framework for diffusion on dynamic mitochondrial networks; Physical vs social mitochondrial network regimes; Four timescales governing diffusion: decay, cluster filling, encounter, fission; Agent-based spherocylindrical model and finite-volume diffusion; Time-resolved imaging and cell-type parameterization (SH-SY5Y, IMR90, U2OS); Predictions of spreading times across cell types

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Connectivity-driven transition between low-dimensional (physical) and three-dimensional (social) network regimes
- Four timescales govern spreading: decay, cluster filling, encounter, and fission
- Spreading times: SH-SY5Y ~6 minutes; IMR90/U2OS ~45 minutes for Dp = 20 μm2/s
- Mobility of mitochondria can bottleneck spreading in fragmented networks
- Active transport increases encounter rates; model primarily assumes diffusion
- Three-cell-line analysis (SH-SY5Y, IMR90, U2OS) used to parameterize the model

QC result: Pass.

346: Palindromes and RNA Self-Recognition

Gustavo Barra — Sun, 19 Apr 2026 00:12:18 +0000

Kimchi O et al., PNAS - This computational study shows that self-complementary RNA regions (palindromes) can drive sequence-specific homotypic clustering by enabling multivalent intermolecular base pairing, and that Drosophila nanos and pgc mRNAs are enriched for accessible, strong palindromes. Key terms: RNA palindromes, homotypic clustering, germ granules, nanos mRNA, phase separation.

Study Highlights:
The authors use equilibrium and nonequilibrium in silico analyses to show palindromic regions increase the likelihood of homodimer and higher-order homomultimer formation. Palindrome binding strength correlates with multimerization propensity, and accessible strong palindromes are enriched in nanos and pgc compared to length-matched Drosophila mRNAs. Out-of-equilibrium calculations indicate initial accessible palindromic interactions can favor homotypic binding despite general heterodimer preference. The framework suggests palindromes could be under evolutionary selection and predicts experimental tests using designed synthetic sequences.

Conclusion:
Palindromic, self-complementary RNA regions provide a generic mechanism for RNA self-recognition and can explain homotypic clustering in germ granules; palindrome content may be under evolutionary selection and can guide experimental tests with synthetic RNAs.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
How do RNA molecules distinguish self from non-self?

First author:
Kimchi O

Journal:
PNAS

DOI:
10.1073/pnas.2603593123

Reference:
Kimchi O, Mitchel K, Pyod AGT, Wingreen NS, Gavis ER. How do RNA molecules distinguish self from non-self? PNAS. 2026;123(15):e2603593123. doi:10.1073/pnas.2603593123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/palindromes-rna-self-recognition

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-04-19.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript portions describing palindromic self-recognition, equilibrium and nonequilibrium modeling, nanos/pgc enrichment, cross-species considerations, GFP tail experiment, evolutionary implications, clinical and synthetic biology implications, and study limitations.
- transcript topics: Palindromic regions as self-recognition mechanism; Equilibrium vs nonequilibrium RNA interactions; Nanos and pgc palindromes: binding strength and accessibility; GFP tail experiment and cross-context clustering; Evolutionary selection and clinical implications; Limitations of in silico modeling and need for in vitro validation

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Palindromic regions enable self-recognition and drive homotypic clustering via multivalent RNA–RNA interactions
- Nanos and pgc RNAs are enriched for accessible, strongly binding palindromes and cluster with their own type
- Out-of-equilibrium modeling shows nanos and pgc have higher homodimer propensity than typical RNAs
- Deleting palindromes abolishes homotypic bias, illustrating necessity of palindromes
- GFP mRNA with nanos tail forms its own homotypic clusters, validating palindrome-driven self-recognition across sequences
- Palindromes are proposed to be under evolutionary selection; content affects clustering across contexts

QC result: Pass.

345: Genes of Prosody: Rhythm, Music, and Reading

Gustavo Barra — Fri, 17 Apr 2026 05:58:08 +0000

Scartozzi AC et al., Human Genetics and Genomics Advances - This episode reviews a GWAS of speech rhythm (prosody) perception using the TOPsy task (n≈1,501 European-ancestry), reporting 14 suggestive loci, nominal enrichment for songbird vocal-learning gene sets, and polygenic links to reading and musical rhythm. Key terms: prosody, speech rhythm, genetics, musical rhythm, reading.

Study Highlights:
The authors performed a GWAS of TOPsy speech rhythm scores in ~1,501 individuals of European genetic ancestry and identified 14 loci reaching suggestive significance but no genome-wide significant hits. Gene-based analyses flagged TTLL1 and GP2 among the top genes without Bonferroni significance. Gene-set enrichment showed nominal overlap with songbird Area X vocal-learning gene sets, consistent with evolutionary convergence hypotheses. Polygenic score analyses demonstrated shared genetic influences between prosody perception and both word reading and beat synchronization, while voice-pitch PGS results were weaker.

Conclusion:
Findings provide initial genomic evidence that prosody perception is polygenic and shares genetic architecture with reading and musical rhythm, and they motivate larger, more diverse samples and scalable phenotyping (TOPsy) to validate and extend these results.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Genome-wide investigation of prosody perception: Shared genetic influences between speech rhythm, musical rhythm, and reading traits

First author:
Scartozzi AC

Journal:
Human Genetics and Genomics Advances

DOI:
10.1016/j.xhgg.2026.100581

Reference:
Scartozzi AC, Wang Y, Coleman PL, et al. Genome-wide investigation of prosody perception: Shared genetic influences between speech rhythm, musical rhythm, and reading traits. Human Genetics and Genomics Advances. 2026;7:100581. https://doi.org/10.1016/j.xhgg.2026.100581

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/genes-of-prosody-rhythm-music-reading

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-04-17.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript sections describing: the definition/importance of prosody and speech rhythm; TOPsy test methodology; GWAS results (no genome-wide hits, 14 suggestive loci); top gene signals (TTLL1 and GP2); cross-species birdsong gene-set enrichment (Area X); polygenic score analyses (word reading, beat synchron
- transcript topics: Definition and importance of prosody and speech rhythm; TOPsy remote 28-item test design and phenotyping; Genome-wide association results for TOPsy (n=1501 European ancestry); Gene-based GWAS signals TTLL1 and GP2; Birdsong gene-set enrichment: Area X and cross-species convergence; Polygenic score analyses: word reading and beat synchronization predicting TOPsy

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 5
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- TOPsy is a 28-item remote, auto-scored test for syllable stress (prosody) perception
- GWAS sample size: 1,501 individuals of European ancestry; λ ~ 1.0065
- No genome-wide significant variant; 14 loci reached suggestive significance (p < 5e-6)
- Top gene-based signals include TTLL1 and GP2
- Birdsong gene sets showed enrichment for Area X (Area X overlap) in humans
- Word reading PGS and beat synchronization PGS predicted TOPsy scores; voice pitch variability PGS weaker and not consistently replicated

QC result: Pass.

344: Homozygous TNNI3 p.Arg136* and severe pediatric restrictive cardiomyopathy

Gustavo Barra — Fri, 17 Apr 2026 05:16:49 +0000

Kühnisch J et al., Human Genetics and Genomics Advances 7, 100598 (2026) - Case report and tissue analysis linking a homozygous TNNI3 nonsense variant (c.406C>T; p.Arg136*) to early-onset, treatment-refractory restrictive cardiomyopathy in a young child who required heart transplantation. Key terms: TNNI3, restrictive cardiomyopathy, pediatric cardiomyopathy, troponin I, protein truncation.

Study Highlights:
A 2-year-old female with severe pediatric restrictive cardiomyopathy carried a homozygous TNNI3 c.406C>T (p.Arg136*) nonsense variant. Myocardial immunostaining showed approximately 50% reduced TNNI3 protein abundance though truncated protein remained detectable. Electron microscopy revealed myofibrillar disarray, irregular Z bands, indistinct M lines, and mitochondrial hyperplasia. The clinical course was treatment refractory and led to heart transplant at 28 months, implicating variant zygosity and truncation position in phenotype determination.

Conclusion:
Biallelic truncation of TNNI3 (p.Arg136*) can cause severe early-onset pediatric restrictive cardiomyopathy, with reduced but partially stable truncated protein and severe sarcomeric pathology prompting early transplantation.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
A homozygous variant in cardiac troponin I3, TNNI3, causes severe pediatric restrictive cardiomyopathy

First author:
Kühnisch J

Journal:
Human Genetics and Genomics Advances 7, 100598 (2026)

DOI:
10.1016/j.xhgg.2026.100598

Reference:
Kühnisch J, Barnett CL, Brendel J, et al. A homozygous variant in cardiac troponin I3, TNNI3, causes severe pediatric restrictive cardiomyopathy. Human Genetics and Genomics Advances. 7:100598. https://doi.org/10.1016/j.xhgg.2026.100598

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/tnni3-arg136-pediatric-rcm

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-04-17.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript's representation of the genetic case, protein expression, tissue analyses, mechanistic interpretation, and genotype–phenotype implications as described in the article.
- transcript topics: RCM vs DCM distinctions; TNNI3 function in the troponin complex; Case presentation and homozygous TNNI3 variant; DNA sequencing and parental segregation; Protein expression by immunostaining; Ultrastructural TEM findings

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Homozygous TNNI3 nonsense variant c.406C>T (p.Arg136*) identified in the proband.
- Proband presented with severe restrictive cardiomyopathy (RCM) requiring heart transplantation at 28 months.
- TNNI3 protein abundance was reduced by approximately 50%, with detectable truncated protein remaining.
- TEM showed sarcomeric disarray and mitochondrial hyperplasia in explanted heart tissue.
- NMD failed to completely eliminate the truncated transcript due to exon 7 being near the end of the gene.
- Heterozygous parents were clinically healthy carriers, supporting non-penetrance of haploinsufficiency in this context.

QC result: Pass.

343: From Cats to Dogs: The Parvovirus Host Jump

Gustavo Barra — Wed, 15 Apr 2026 09:37:46 +0000

López-Astacio RA et al., PNAS - Analysis of 60 years of feline panleukopenia virus genomes traces the origins of canine parvovirus, identifies vaccine-derived sequences, and documents distinct evolutionary rates and capsid adaptations that enabled a host jump to dogs. Key terms: parvovirus, FPV, CPV, host jump, evolution.

Study Highlights:
Using full-genome sequencing and phylogenetics, the authors compare 60 years of FPV evolution with 47 years of CPV evolution and identify vaccine-derived sequences that cluster with early isolates. FPV evolves at roughly one-third the rate of CPV in dogs, while the CPV ancestor is closely related to European FPV-like strains and carries multiple capsid mutations linked to binding the canine transferrin receptor. Live-attenuated FPV vaccines derive from early 1960s isolates and FPV shows little antigenic selection compared to the faster-evolving CPV lineage. These patterns emphasize distinct evolutionary dynamics in reservoir versus new hosts during epidemic emergence.

Conclusion:
A single FPV-related lineage from Europe accumulated multiple capsid changes enabling canine TfR binding and gave rise to the CPV pandemic; thereafter CPV evolved approximately 3–4 times faster in dogs, while FPV in its reservoir hosts showed slow evolution with limited antigenic change and persistent vaccine-derived genomes in databases.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Distinct evolutionary patterns of endemic and emerging parvoviruses and the origin of a new pandemic virus

First author:
López-Astacio RA

Journal:
PNAS

DOI:
10.1073/pnas.2515274123

Reference:
López-Astacio RA, Wasik BR, Lee H, Voorhees IEH, Weichert WS, Adu OF, Goodman LB, Hafenstein SL, Truyen U, Parrish CR. Distinct evolutionary patterns of endemic and emerging parvoviruses and the origin of a new pandemic virus. PNAS. 2026;123(16):e2515274123. doi:10.1073/pnas.2515274123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/feline-to-canine-parvovirus-origins

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-04-15.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript sections describing FPV reservoir, CPV emergence, TfR binding and glycosylation barriers, VP2/other capsid mutations, evolutionary rates, vaccine-derived FPV sequences, antigenic variation, intermediate hosts, and missing ancestral link.
- transcript topics: FPV feline reservoir and CPV emergence; Transferrin receptor binding and canine TfR glycosylation barrier; VP2 mutations and host-range adaptation; Evolutionary rates FPV vs CPV and molecular clock methods; Vaccine-derived FPV sequences and vaccine filtering; Antigenic variation in FPV vs CPV and vaccine efficacy

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- CPV originated from European FPV lineage with host-range mutations enabling canine TfR binding
- CPV substitution rate in dogs is approximately 2.18×10^-4 substitutions/site/year; FPV in cats approximately 5.78×10^-5 substitutions/site/year
- Twelve nonsynonymous and ten synonymous substitutions on the CPV-2 branch; nine nonsynonymous substitutions occurred in VP2, with changes near the threefold spike affecting host ra
- FPV vaccine strains derive from 1960s isolates; many FPV-like sequences in databases are vaccine-derived or recombinant; vaccine-derived sequences can confound analyses
- FPV shows limited antigenic variation; CPV exhibits more antigenic variation, but vaccines remain broadly protective due to polyclonal responses
- Raccoons (and other noncanine hosts) proposed as intermediate hosts that could accumulate mutational combinations before canine adaptation

QC result: Pass.

342: Modular MPRA Reveals Context-Dependent Regulation at T2D Loci

Gustavo Barra — Tue, 14 Apr 2026 07:38:41 +0000

Tovar A et al., Human Genetics and Genomics Advances - This episode examines a study that used a modular MPRA to test ~11,656 genomic fragments from T2D- and metabolic trait-associated regions in pancreatic beta cells, comparing upstream vs downstream positions and SCP1 vs INS promoters. The work identifies promoter- and position-dependent regulatory activity and implicates HNF1 motifs in INS promoter-specific effects. Key terms: massively parallel reporter assay, type 2 diabetes, noncoding regulation, HNF1, promoter-enhancer compatibility.

Study Highlights:
The authors screened nearly 12,000 fragments across T2D- and metabolic trait-associated regions in a pancreatic beta cell model using four MPRA configurations (up/down × SCP1/INS). They found ~6% of fragments show significant promoter bias and ~6% show position bias, with INS-preferring fragments enriched for HNF1 motifs. Targeted motif perturbation MPRA showed HNF1 motif disruption reduced activity specifically in the INS promoter context and in beta cells but not in skeletal muscle, indicating cell-type and promoter-specific regulatory dependencies. The results highlight that MPRA construct design choices materially affect detection and interpretation of regulatory activity.

Conclusion:
Promoter identity and fragment position influence MPRA-detected regulatory activity, and tissue-specific promoters (like INS) can reveal TF-dependent regulatory mechanisms (e.g., HNF1) at T2D-linked noncoding regions.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Using a modular massively parallel reporter assay to discover context-dependent regulatory activity in type 2 diabetes-linked noncoding regions

First author:
Tovar A

Journal:
Human Genetics and Genomics Advances

DOI:
10.1016/j.xhgg.2026.100606

Reference:
Tovar A, Kyono Y, Nishino K, Bose M, Varshney A, Parker SCJ, Kitzman JO. Using a modular massively parallel reporter assay to discover context-dependent regulatory activity in type 2 diabetes-linked noncoding regions. Human Genetics and Genomics Advances (2026). doi: https://doi.org/10.1016/j.xhgg.2026.100606

License:
http://creativecommons.org/licenses/by-nc-nd/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/modular-mpra-t2d-context-dependent-regulation

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-04-14.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the scientific content describing MPRA design parameters, library size, cell models, promoter/position bias findings, HNF1 motif associations and perturbations, and cross-tissue results as presented in the transcript.
- transcript topics: MPRA design configurations (promoter: INS vs SCP1; position: upstream vs downstream); Library scale and construction (11,656 fragments; ~13,226 sites; 198-bp fragments with adapters); Cell models used (832/13 rat beta-cell line; LHCN-M2 human skeletal muscle cells); Promoter bias findings (INS promoter bias ~73.4%; 698 fragments promoter-biased); Position bias findings (703 fragments showing upstream/downstream bias); Motif enrichment and HNF1A/B associations with INS promoter activity

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license
- episode_title

Factual Items Audited:
- MPRA design configurations: upstream vs downstream relative to INS and SCP1 promoters
- Library size: ~11,656 fragments across 4 configurations (out of ~13,226 targeted sites)
- Cell models: 832/13 rat insulinoma beta cells and LHCN-M2 human skeletal muscle myoblasts
- Promoter bias: 698/11,656 fragments show significant promoter effects; INS bias ~73.4% of promoter-biased fragments
- Position bias: 703/11,656 fragments show significant upstream/downstream bias
- HNF1 motif enrichment among INS-promoter-biased fragments; NKX6.1 also involved

QC result: Pass.

341: The Genetic Lottery and the Value of an Extra Year of School

Gustavo Barra — Mon, 13 Apr 2026 09:10:52 +0000

Widding-Havneraas T et al., PNAS - This study uses genetic variation related to educational attainment as a quasi-experimental instrument (Mendelian randomization) together with Norwegian registry data to estimate the causal return to an additional year of schooling on labor-market earnings. Key terms: returns to education, Mendelian randomization, polygenic index, Norwegian registries, life-cycle earnings.

Study Highlights:
The authors triangulate OLS, sibling and twin fixed-effects, and Mendelian randomization (MR) using a 335-SNP polygenic index to estimate returns to schooling in Norwegian population and MoBa samples. OLS estimates an additional year of schooling raises prime-age earnings by about 5.9%, sibling FE by 5.3%, MZ twin FE by 3.3%, and MR by 8.0% (with a Norway-only MR estimate of 9.7%). Life-cycle analyses show negative early-career returns that turn positive around age 27 and grow thereafter. Internal rates of return across models exceed the market interest rate, indicating education is profitable over the life cycle.

Conclusion:
Using genetically informed quasi-experiments, one additional year of schooling causally increases annual earnings (MR ~8%), and education appears to pay off across the life cycle.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Estimating returns to education using the genetic lottery

First author:
Widding-Havneraas T

Journal:
PNAS

DOI:
10.1073/pnas.2537049123

Reference:
Widding-Havneraas T, Demange PA, Zachrisson HD, Borgen N, Ystrom E, Elwert F. Estimating returns to education using the genetic lottery. PNAS. 2026;123(15):e2537049123. https://doi.org/10.1073/pnas.2537049123. Published April 8, 2026.

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/genetic-lottery-returns-to-education

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-04-13.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Substantive audit focused on the episode’s discussion of methodology, key numerical results, lifecycle interpretation, and robustness checks as presented in the original article.
- transcript topics: Causality vs correlation in education and earnings; Mendelian randomization as a quasi-experiment; 335-SNP polygenic index as educational attainment instrument; Comparison across identification strategies: OLS, sibling, DZ/MZ twins, MR; Compliers and nonshared environments; Life-cycle returns and age-27 crossover

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license
- episode_title
- episode_number
- season

Factual Items Audited:
- MR estimate: 8.0% increase in lifetime earnings per additional year of schooling
- OLS estimate: 5.9% increase per additional year of schooling
- Norway-only MR estimate: 9.7% per additional year
- Internal rate of return (IRR) to schooling: 10.1%
- Crossover age where returns become positive: about age 27
- Women experience higher financial returns to schooling than men

QC result: Pass.

340: Microexon Control of Behavior — PTPRD Splicing

Gustavo Barra — Sun, 12 Apr 2026 10:19:03 +0000

Imai A et al., Proceedings of the National Academy of Sciences (PNAS) - This paper shows that alternative splicing of a 12-nt microexon (meB) in Ptprd is regulated by a genetic intronic enhancer and an activity-dependent intronic silencer to set region- and age-specific ratios of PTPRD splice variants. Manipulating these intronic elements in mice changes the proportion of meB-containing isoforms without altering total PTPRD protein and produces distinct behavioral consequences. Key terms: microexon, alternative splicing, PTPRD, synaptogenesis, behavior.

Study Highlights:
The authors mapped eight Ptprd splice variants across brain regions and ages and found neuronal activity induces rapid meB skipping. They identified a 316-bp intronic splicing enhancer (ISE) whose heterozygous deletion reduced meB selection by ~25% and caused broad sensory, motor, social, and emotional deficits. They also identified a 420-bp intronic splicing silencer (ISS) required for activity-dependent meB skipping; deletion of the ISS produced selective impairments in motor learning and remote cued fear memory. These results indicate that the spatiotemporal and activity-dependent AS code of a four–amino-acid microexon sculpts synaptogenic properties and behavioral development.

Conclusion:
Spatiotemporal and activity-dependent alternative splicing of a single four–amino-acid microexon in Ptprd controls the balance of PTPRD splice variants and is essential for normal behavioral development in mice.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Alternative microexon splicing code for a four - amino acid peptide of PTPRD governs behavioral development

First author:
Imai A

Journal:
Proceedings of the National Academy of Sciences (PNAS)

DOI:
10.1073/pnas.2515310123

Reference:
Imai A, Izumi H, Ito N, et al. Alternative microexon splicing code for a four-amino acid peptide of PTPRD governs behavioral development. Proc Natl Acad Sci U S A. 2026;123(15):e2515310123. doi:10.1073/pnas.2515310123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/ptprd-microexon-ep340

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-04-12.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the scientific narrative in the transcript related to Ptprd microexon meB regulation, the regulatory elements ISE and ISS, bead-coculture experiments, in vivo CRISPR mouse models (ISE and ISS mutations), activity-dependent skipping, and the resulting behavioral and learning/memory phenotypes, as well as the pro
- transcript topics: Ptprd microexon meA3, meA6, meB and eight splice variants; Bead coculture assay to test synaptogenicity and ligand interactions (Shank2, gephyrin, NLGN3); Genetic regulation of meB: intronic splicing enhancer (ISE); Activity-dependent regulation of meB: intronic splicing silencer (ISS); In vivo CRISPR mouse models: Ptprd+/dISE, PtprddISE/dISE, PtprddISS/dISS; Neuronal activity and rapid meB skipping (1 hour after KCl)

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Eight Ptprd splice variants arise from combinations of meA3, meA6, and meB, with region- and age-specific distributions
- An upstream intronic splicing enhancer (ISE) of Ptprd meB regulates inclusion; its deletion reduces meB selection by about 25% with no change to total PTPRD
- An activity-dependent intronic splicing silencer (ISS) regulates meB skipping; deletion increases meB exclusion to near 100% and impairs motor learning and remote fear memory
- Neuronal activity (KCl) rapidly increases meB skipping within 1 hour
- A 50% reduction in total PTPRD with normal splice ratios yields fewer behavioral abnormalities than a 25% shift in splice ratio
- Dysregulation of Ptprd microexons is linked to ASD-like phenotypes and may be therapeutically targetable via splicing ratio modulation

QC result: Pass.

339: cxt: A language model for population genetics

Gustavo Barra — Sat, 11 Apr 2026 18:05:29 +0000

Korfmann K et al., Proceedings of the National Academy of Sciences (PNAS) - This episode examines cxt, a decoder-only transformer that performs next-coalescence prediction by translating local mutational context into pairwise TMRCA estimates. Trained on stdpopsim simulations, cxt delivers rapid, scalable coalescence-time inference, calibrated posteriors, and practical adaptations for empirical data. Key terms: language models, coalescent theory, uncertainty, stdpopsim, simulation-based inference.

Study Highlights:
The authors develop cxt, an autoregressive transformer that predicts discretized pairwise coalescence times from SFS-weighted mutation windows, framing TMRCA inference as a translation task. Trained on extensive stdpopsim simulations, cxt matches state-of-the-art accuracy in well-specified settings and generalizes to many out-of-sample species with some loss of accuracy. The model produces well-calibrated approximate posteriors, enables rapid GPU inference (millions of predictions in minutes), and can be fine-tuned or adapted for large Ne, missing data, or small sample sizes. Applications to human and Anopheles genomes recover known signals at LCT, HLA, inversion regions, and the Rdl insecticide-resistance locus.

Conclusion:
cxt reframes coalescent inference as a language-modeling problem, providing a fast, scalable, and adaptable tool that learns priors from simulations to infer local TMRCA and aggregate demography while offering uncertainty quantification through approximate posteriors.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Accessible, realistic genome simulation with selection using stdpopsim

First author:
Korfmann K

Journal:
Proceedings of the National Academy of Sciences (PNAS)

DOI:
10.1073/pnas.2518956123

Reference:
Korfmann K., Pope N. S., Meleghy M., Tellier A., Kern A. D. Coalescence and translation: A language model for population genetics. Proc. Natl. Acad. Sci. U.S.A. 2026;123:e2518956123. doi:10.1073/pnas.2518956123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/cxt-language-model-for-population-genetics

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-04-11.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited transcript sections describing the cxt model (architecture and next-coalescence prediction), training on stdpopsim, performance benchmarks, generalization to unseen species, empirical data applications (LCT, HLA, Rdl), missing data handling/adapters, and environmental considerations.
- transcript topics: ARG basics and coalescent theory as context; cxt architecture: decoder-only transformer and next-coalescence prediction; input encoding: mutational densities, SFS, rotary embeddings; training data: stdpopsim simulations and catalog breadth; benchmark comparisons: Singer+Polegon and SMC++; generalization to stdpopsim v0.3 and unseen species

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- cxt is a decoder-only transformer that autoregressively predicts local coalescence times (TMRCA) via next-coalescence prediction
- Trained on stdpopsim simulations; generalizes across demographies, including unseen species
- Inference is fast (millions of TMRCAs in minutes) on a single NVIDIA A100 GPU
- cxt yields well-calibrated approximate posteriors for TMRCA
- Compared to Singer+Polegon and SMC++, cxt is competitive and often superior in well-specified/out-of-distribution scenarios
- Empirical data show clear LCT and HLA signals in humans and Rdl dynamics in Anopheles; missing data handling improves robustness

QC result: Pass.

338: WDHD1 and Microcephalic Primordial Dwarfism

Gustavo Barra — Fri, 10 Apr 2026 15:38:15 +0000

Tibbe D et al., The American Journal of Human Genetics - This study identifies bi-allelic hypomorphic WDHD1 variants in 17 subjects with a clinical spectrum from fetal lethality to microcephalic primordial dwarfism and characterizes cellular defects in patient-derived cells linked to replisome dysfunction. Key terms: WDHD1, microcephalic primordial dwarfism, replication stress, sister chromatid cohesion, splicing variants.

Study Highlights:
Researchers found bi-allelic WDHD1 variants in 17 subjects presenting with intrauterine growth retardation, microcephaly and a spectrum of organ abnormalities including neonatal acute liver failure. Several intronic variants cause aberrant splicing and markedly reduced WDHD1 protein levels in fibroblasts. Subject-derived cells showed slowed replication fork progression, impaired G1-to-S transition, increased spontaneous DNA damage, abnormal nuclear morphology, and elevated premature sister chromatid separation, supporting a role for WDHD1 in replisome stability and cohesion.

Conclusion:
Hypomorphic bi-allelic WDHD1 variants cause an autosomal recessive microcephalic primordial dwarfism spectrum by reducing WDHD1 protein and impairing replication fork stability, genome integrity, and sister chromatid cohesion, establishing WDHD1 as essential for normal human growth and development.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Bi-allelic WDHD1 variants cause microcephalic primordial dwarfism

First author:
Tibbe D

Journal:
The American Journal of Human Genetics

DOI:
10.1016/j.ajhg.2026.03.010

Reference:
Tibbe D., Vogt M.R., Holling T., et al. Bi-allelic WDHD1 variants cause microcephalic primordial dwarfism. The American Journal of Human Genetics. 2026. https://doi.org/10.1016/j.ajhg.2026.03.010

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/wdhd1-microcephalic-primordial-dwarfism

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-04-10.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript's coverage of WDHD1 function as replisome scaffold; intronic WDHD1 variants and splicing; DNA fiber assay and replication fork dynamics; γH2AX signaling; nuclear morphology; PCS; and liver pathology in MPD.
- transcript topics: WDHD1 as replisome scaffold; intronic WDHD1 variants and splicing; DNA fiber assay and replication fork speed; γH2AX DNA damage signaling; nuclear morphology and lamin B1; premature sister chromatid separation (PCS)

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- 17 subjects from 14 families with bi-allelic WDHD1 variants and MPD spectrum
- intronic WDHD1 variants cause aberrant splicing and markedly reduced WDHD1 protein levels in patient-derived cells
- WDHD1 acts as replisome scaffolding to stabilize replication forks and maintain genome integrity
- replication fork progression is slowed and there is increased spontaneous DNA damage (γH2AX); nuclear morphology is disrupted; PCS increased
- acute liver failure observed in a subset of neonatal subjects; liver vulnerability discussed in the context of replication stress and polyploidization

QC result: Pass.

337: ND-CNVs and internalizing–cardiometabolic multimorbidity

Gustavo Barra — Wed, 08 Apr 2026 23:56:34 +0000

Katzourou IK et al., The American Journal of Human Genetics - Population analysis of ~459,000 UK Biobank participants shows that carriers of neurodevelopmental CNVs (ND-CNVs) have higher odds of co-occurring internalizing (depression, anxiety, somatic) and cardiometabolic conditions (hypertension, dyslipidemia, obesity, T2D, CKD). Effects are stronger for deletions than duplications, greater in females, and linked to the number of haploinsufficient genes within deletions. Key terms: copy-number variants, multimorbidity, internalizing disorders, cardiometabolic, UK Biobank.

Study Highlights:
Using CNV calls and linked EHRs in the UK Biobank, the authors tested associations between 54 ND-CNVs and combinations of internalizing and cardiometabolic conditions (ICM-MM). Aggregated ND-CNV carriers (n≈7,546; ~1.6%) had higher odds of ICM-MM (OR range 1.21–1.57) and a higher ICM-MM frequency (14.2% vs 11.5%). Deletions showed stronger effects than duplications and the number of haploinsufficient genes in deletions was associated with greater ICM-MM risk. No robust interactions were detected between ND-CNV status and polygenic risk scores after multiple testing correction.

Conclusion:
ND-CNVs increase risk of internalizing–cardiometabolic multimorbidity at the population level, especially for deletions and in females, suggesting the need for heightened clinical monitoring of carriers.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Neurodevelopmental copy-number variants increase risk of internalizing and cardiometabolic multimorbidity: Findings from the UK Biobank

First author:
Katzourou IK

Journal:
The American Journal of Human Genetics

DOI:
10.1016/j.ajhg.2026.02.021

Reference:
Katzourou IK, LINC consortium, Barroso I, et al. Neurodevelopmental copy-number variants increase risk of internalizing and cardiometabolic multimorbidity: Findings from the UK Biobank. The American Journal of Human Genetics. 2026;113:1–11. https://doi.org/10.1016/j.ajhg.2026.02.021

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/nd-cnv-internalizing-cardiometabolic-multimorbidity

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-04-08.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited transcript sections covering ND-CNV–ICM-MM association, UK Biobank design and CNV calling, dosage-sensitivity (haploinsufficient vs triplosensitive), deletion vs duplication effects (notably 16p11.2), sex differences, PRS interaction analyses, and clinical implications including multidisciplinary care and casca
- transcript topics: Definition of ND-CNVs and ICM-MM; UK Biobank cohort size, CNV calling methods (PennCNV); Dosage sensitivity: haploinsufficient vs triplosensitive genes; Deletion vs duplication effects on ICM-MM and obesity; 16p11.2 region emphasis; Sex differences in ND-CNV associations

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- ND-CNVs increase risk of internalizing–cardiometabolic multimorbidity (ICM-MM) in UK Biobank with OR 1.21–1.57 and 14.2% vs 11.5% prevalence
- Deletions show stronger effects than duplications; 16p11.2 region deletions are notable
- The number of haploinsufficient genes within deletions is associated with higher ICM-MM; duplications' triplosensitive genes do not show the same pattern
- No robust ND-CNV × PRS interactions after multiple-testing correction; nominal interactions present in some PRS analyses
- Sex differences: higher risk in females for certain ND-CNV associations (e.g., T2D, internalizing)
- Survival bias in UK Biobank implies observed effect sizes are conservative lower bounds

QC result: Pass.

336: Measuring disease likelihood in genomic ascertainment

Gustavo Barra — Tue, 07 Apr 2026 22:53:17 +0000

Sapp JC et al., The American Journal of Human Genetics - A longitudinal study of recipients of medically actionable secondary genomic findings develops a Bayesian approach that integrates variant, family genotypic, and phenotypic data to estimate the probability that a secondary finding represents a true clinicomolecular diagnosis, with a detailed analysis of BRCA1/BRCA2 families and implications for screening policy and clinical management. Key terms: secondary findings, BRCA1, BRCA2, Bayesian risk assessment, population genomic screening.

Study Highlights:
The team enrolled 227 secondary findings recipients and completed genotyping and deep phenotyping for 163 probands, using cascade testing and variant reclassification. They piloted a Bayesian method combining prior population prevalence, variant pathogenicity, and family genotype–phenotype data to estimate clinicomolecular diagnosis (CMD) probabilities for BRCA1/2 families. CMD probabilities varied widely (26.2% to >99.9%) and over half of BRCA1/2 families met NCCN diagnostic testing criteria, indicating underuse of diagnostic testing.

Conclusion:
In opportunistic secondary findings contexts the posterior probability that a patient has the implicated monogenic disease can differ substantially from variant pathogenicity; integrating familial genotypic and phenotypic data via Bayesian methods refines risk estimates and should guide shared decision-making, management strategies, and policy for population genomic screening.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Measuring disease likelihood in genomic ascertainment

First author:
Sapp JC

Journal:
The American Journal of Human Genetics

DOI:
10.1016/j.ajhg.2026.03.009

Reference:
Sapp JC, Lewis KL, Modlin EW, et al. Measuring disease likelihood in genomic ascertainment. The American Journal of Human Genetics. 2026;113:1–12. doi:10.1016/j.ajhg.2026.03.009

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/measuring-disease-likelihood-genomic-ascertainment

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-04-07.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited transcript sections describing the Bayesian CMD approach, the BRCA1/BRCA2 findings, the Family 8334 case, NCCN criteria implications, and study design/limitations.
- transcript topics: ACMG secondary findings context and selection bias; Bayesian probability model for CMD; Cascade testing and family data integration; BRCA1 vs BRCA2 variant distribution and penetrance; NCCN criteria and clinical testing underutilization; Study design and recruitment (163 probands from 41 sources)

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 5
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- CMD probability range across BRCA1/BRCA2 families: 26.2% to 100%
- Baseline posterior probability for BRCA2-related CMD: 58.2%
- Posterior CMD probability for family 8334: 99.2%
- Average CMD probability across BRCA1/BRCA2 families: 86.9%
- BRCA2 variants comprised 83% and BRCA1 17% of BRCA1/BRCA2 findings
- 51% of BRCA1/BRCA2 families met NCCN diagnostic testing criteria

QC result: Pass.

335: Altai Neandertal Genome Reveals Deep Population Structure

Gustavo Barra — Sun, 05 Apr 2026 20:36:49 +0000

Massilania D et al., PNAS - We summarize a PNAS study reporting a ~37× genome from a ~110,000-year-old male Neandertal (Denisova 17) from Denisova Cave. The genome shows D17 is closely related to an earlier Denisova Neandertal (D5), both carry Denisovan introgressed segments, and Neandertal groups displayed high regional differentiation and small, isolated populations in the Altai. Key terms: Neandertal, Denisova Cave, genome sequencing, population structure, Denisovan admixture.

Study Highlights:
The authors generated a high-coverage (~37-fold) autosomal genome from a ~110,000-year-old male Neandertal (D17) from Denisova Cave and dated it to ~110 kya. D17 is more closely related to an older Denisova Neandertal (D5) than to European or other Altai Neandertals and both D5 and D17 contain Denisovan-derived genomic segments. Patterns of homozygosity indicate smaller, more isolated groups in Altai Neandertals compared with later European Neandertals. Estimated FST shows Eastern and Western Neandertals were as genetically differentiated as the most divergent present-day human populations, implying rapid drift under small effective sizes.

Conclusion:
A high-coverage Altai Neandertal genome reveals Denisovan admixture in older eastern Neandertals, small and isolated group sizes in the Altai, and pronounced east–west Neandertal population differentiation exceeding that seen among modern human populations.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
A high-coverage Neandertal genome from the Altai Mountains reveals population structure among Neandertals

First author:
Massilania D

Journal:
PNAS

DOI:
10.1073/pnas.2534576123

Reference:
Massilania D, Peyrégne S, Iasi LN M, de Filippo C, Mafessoni F, Mesab AB, Sümer AP, Swiel Y, Popli D, Silverman S, Boylea MJ, Kozlikind MB, Shunkov MV, Derevianko AP, Higham T, Douka K, Meyer M, Zeberg H, Kelso J, Pääbo S. A high-coverage Neandertal genome from the Altai Mountains reveals population structure among Neandertals. PNAS. 2026;123(13):e2534576123. doi:10.1073/pnas.2534576123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/d17-altai-neandertal-genome-structure

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-04-05.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Substantive audit focused on the transcript sections describing: specimen, sequencing coverage, population structure, Denisovan admixture, autozygosity and small group sizes, FST differentiation, and dating of D17/D5 lineages, plus migration/replacement dynamics.
- transcript topics: Denisova 17 (D17) DNA extraction and high-coverage genome (~37x); Relationship among Neandertals (D17, D5, Chag8, Vi33.19) and Denisovans; Denisovan introgression into D17 and D5; lack of clear Denisovan signal in Chag8; Autozygosity and small population sizes (<50 individuals) in Eastern Neandertals; Genetic differentiation (FST ~0.30) between Eastern and Western Neandertals; Molecular dating and age estimates for D17 (~110 kya) and Y-chromosome lineage

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- D17 high-coverage Neandertal genome (~37× autosomal coverage)
- D17, D5 show Denisovan introgression; Chag8 shows little to no Denisovan admixture
- D17 shares more derived alleles with D5 than with Vi33.19 or Chag8
- Eastern and Western Neandertals have FST ≈ 0.30, greater differentiation than most modern human pairs
- D17 estimated age ~110 thousand years (autosomal molecular dating)
- D5 ~8,000 years older than D17 in Denisovan introgression timing

QC result: Pass.

334: LINE-1 Recombination with Diverse RNAs

Gustavo Barra — Sun, 05 Apr 2026 19:19:16 +0000

Law C-T et al., Cell Genomics - Law and Burns introduce TiMEstamp, a comparative-genomics pipeline that dates LINE-1 insertions from multiple sequence alignments and discovers hundreds of LINE-1 chimeric insertions fused to diverse RNAs across mammalian evolution. Key terms: LINE-1, TiMEstamp, chimeric insertions, retrotransposition, comparative genomics.

Study Highlights:
The authors developed TiMEstamp to infer TE insertion times from multispecies MSAs and to detect contemporaneous 5′ sequences fused to LINE-1. They compiled a large catalog of LINE-1 chimeras (reported >700 events) including known U6/LINE-1 cases and newly identified partners such as tRNA, 28S rRNA, 7SL, Y RNA, Alu elements, and mRNA 5′ transductions. Alu/LINE-1 chimeras (452 events) and 17 mRNA/lncRNA 5′ transductions were characterized with TSDs, EN motifs, and orientation/length patterns. They also show that promoter co-option (e.g., RAP1GDS1 driving a spliced intronic L1PA2) can restore retrotransposition competence.

Conclusion:
Comparative MSA-based timing reveals widespread, recurrent recombination between LINE-1 RNA and diverse cellular RNAs, producing chimeric insertions that have contributed to transposon diversification and provide mechanisms (RNA ligation, template switching, twin priming, promoter co-option) that may influence TE evolution and somatic/germline retrotransposition.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Comparative genomics reveals LINE-1 recombination with diverse RNAs

First author:
Law C-T

Journal:
Cell Genomics

DOI:
10.1016/j.xgen.2026.101165

Reference:
Law C-T and Burns K.H., 2026. Comparative genomics reveals LINE-1 recombination with diverse RNAs. Cell Genomics 6, 101165. https://doi.org/10.1016/j.xgen.2026.101165

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/line1-recombination-diverse-rnas

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-04-05.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited sections covering the TiMEstamp workflow and data (MSA across mammals), discovery of chimeric LINE-1 insertions (tRNA halves, 28S rRNA, 7SL, Y RNA, 7SK), Alu/LINE-1 chimeras, mRNA/lncRNA 5' transductions (MAP3K13, FHIT), RAP1GDS1 promoter co-option, twin priming and trans-splicing mechanisms, and study limitati
- transcript topics: LINE-1 retrotransposition mechanics (TPRT); TiMEstamp methodology and MSA dating; Chimeric LINE-1 insertions with non-LINE-1 RNAs (tRNA halves, 28S rRNA, 7SL, Y RNA, 7SK RNA); Alu/LINE-1 chimeras and temporal activity; 5′ transductions involving mRNAs/lncRNAs (MAP3K13, FHIT, RAP1GDS1); RAP1GDS1 promoter co-option and transcriptional rescue

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- TiMEstamp uses MSAs across mammals to date LINE-1 insertions and identify contemporaneous adjacencies
- Chimeric LINE-1 insertions involve diverse RNAs including tRNA halves, 28S rRNA, 7SL RNA, Y RNA, and 7SK RNA
- Alu/LINE-1 chimeras total 452 events with EN motifs in many cases and predominantly sense orientation
- 17 chimeric LINE-1 insertions involving protein-coding mRNAs or lncRNAs (e.g., MAP3K13, FHIT) identified; 5′ exons implicated
- RAP1GDS1 intronic L1PA2 co-opted promoter drives LINE-1 transcription/retrotransposition in brain
- Twin priming and trans-splicing signatures observed in chimeric insertions

QC result: Pass.

333: Holistic determination of cfDNA ends

Gustavo Barra — Sat, 04 Apr 2026 17:32:23 +0000

Jiang P et al., Cell Genomics - This episode reviews a Cell Genomics study that uses ssDNA '2-end' and novel '4-end' sequencing to profile native 5′ and 3′ termini of plasma cfDNA. The work identifies PREM/POEM markers, links 3′ ends to methylation, and shows improved HCC detection. Key terms: cfDNA fragmentomics, 3' end motifs, 4-end sequencing, hepatocellular carcinoma, DNASE1L3.

Study Highlights:
The authors adapted single-stranded library preparation (2-end sequencing) to measure native 5′ (EM5) and 3′ (EM3) end motifs and defined flanking PREM and POEM motifs. Combining size‑stratified PREM, EM5, EM3, and POEM features raised hepatocellular carcinoma (HCC) detection to an AUC of 0.95. Fragmentomics-based methylation analysis of 3′ ends (3′ FRAGMA) improved HCC detection further (AUC 0.97). A novel 4-end sequencing approach captured all four termini of double‑stranded cfDNA, yielding 4‑end motif models with AUC up to 0.98 and revealing coordinated nuclease activity, notably DNASE1L3 involvement.

Conclusion:
Holistic end profiling of cfDNA—integrating native 5′ and 3′ ends, flanking motifs, methylation-informed fragmentomics, and four‑end resolution—enhances cancer detection performance and provides mechanistic insight into coordinated nuclease-mediated fragmentation, warranting larger validation studies.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Holistic determination of ends of cfDNA molecules

First author:
Jiang P

Journal:
Cell Genomics

DOI:
10.1016/j.xgen.2026.101142

Reference:
Jiang P., Ma M.-J. L., Qiao R., et al. Holistic determination of ends of cfDNA molecules. Cell Genomics. 2026;6:101142. doi:10.1016/j.xgen.2026.101142

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/holistic-cfdna-ends-episode-333

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-04-04.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript’s substantive description of 2-end sequencing (EM5/EM3), PREM/POEM, 3'-FRAGMA, 4-end sequencing, nuclease signatures (DNASE1L3, DNASE1, DFFB), HCC diagnostic performance (AUC values), fragment-size context, and translational limitations as reported in the article.
- transcript topics: 2-end sequencing preserving native ends (EM5/EM3); Pre-end (PREM) and post-end motifs (POEM); 4-end sequencing with stem-loop adapters and PacBio SMRT; 3'-FRAGMA methylation analysis; Nuclease-specific end motifs and coordinated fragmentation (DNASE1L3, DNASE1, DFFB); HCC detection performance and AUC values

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license
- episode_title
- episode_number
- season

Factual Items Audited:
- 2-end sequencing preserves native 5' and 3' ends (EM5/EM3) by omitting end-repair during library prep
- PREM and POEM motifs are defined and analyzed as end-motif neighbors around EM5 and EM3
- 4-end sequencing enables simultaneous assessment of all four termini using stem-loop adapters and PacBio SMRT sequencing
- 3'-FRAGMA shows methylation-associated fragmentation patterns and improves HCC detection (AUC 0.97)
- Combined end-motif analysis across PREM, EM5, EM3, and POEM yields AUC ≈ 0.95 for HCC detection
- DNASE1L3 identified as a major contributor to cfDNA fragmentation; DNASE1L3 knockout mice alter motif frequencies

QC result: Pass.

333: Holistic determination of cfDNA ends

Gustavo Barra — Sat, 04 Apr 2026 17:32:23 +0000

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Holistic determination of ends of cfDNA molecules

First author:
Jiang P

Journal:
Cell Genomics

DOI:
10.1016/j.xgen.2026.101142

Reference:
Jiang P., Ma M.-J. L., Qiao R., et al. Holistic determination of ends of cfDNA molecules. Cell Genomics. 2026;6:101142. doi:10.1016/j.xgen.2026.101142

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/holistic-cfdna-ends-episode-333

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-04-04.

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

QC result: Pass.

332: When Chromatin Filters Force: Age, AP-1, and Fibroblast Mechanotransduction

Gustavo Barra — Thu, 02 Apr 2026 08:38:29 +0000

Liao Y et al., PNAS - Human dermal fibroblasts from young and old donors were embedded in 3D collagen and exposed to mechanical tension and TGF-β. Combining bulk RNA‑seq, ATAC‑seq, imaging, and perturbations, the study shows that matrix tension amplifies TGF‑β responses in young but not aged cells and identifies AP‑1 as a central chromatin-associated regulator required for fibroblast activation. Key terms: chromatin accessibility, mechanotransduction, aging, TGF-β signaling, AP-1.

Study Highlights:
Young fibroblasts under matrix tension mount a strong, synergistic transcriptional response to TGF‑β while aged fibroblasts exhibit blunted or divergent responses. Age-dependent differences in chromatin accessibility, notably at distal regulatory elements, correlate with these transcriptional outcomes. AP‑1 family motifs are highly enriched in TGF‑β- and age-responsive accessible regions and cooperate with age-specific TFs. Inhibiting AP‑1 activity prevents JUNB recruitment to RNA polymerase II and suppresses myofibroblast activation.

Conclusion:
3D chromatin accessibility acts as a dynamic filter of mechanical and biochemical signals during aging; AP‑1 and its regulatory network drive the age-specific chromatin remodeling that permits synergistic tension + TGF‑β responses in young fibroblasts, and AP‑1 inhibition blocks this activation, suggesting a potential therapeutic axis.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Chromatin accessibility regulates age- dependent nuclear mechanotransduction

First author:
Liao Y

Journal:
PNAS

DOI:
10.1073/pnas.2522217123

Reference:
Liao Y, Land M, Gupta R, Yu L, Sornapudi TR, Shivashankar GV. Chromatin accessibility regulates age-dependent nuclear mechanotransduction. PNAS. 2026;123(13):e2522217123. doi:10.1073/pnas.2522217123. Published March 26, 2026.

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/base-by-base-332-chromatin-age-mechanotransduction

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-04-02.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Substantive auditing covered the study’s central mechanistic story: aging as a chromatin-filter for mechanochemical signaling; AP-1 as master regulator; age-specific TF partnerships; the 3D collagen tension model; ATAC-seq/RNA-seq integration; and AP-1 perturbation experiments.
- transcript topics: Aging as chromatin-based signaling filter; 3D collagen gel tension model with glass ring; TGF-β signaling and mechanical tension synergy; AP-1 as master regulator; age-specific partners (JUNB vs HOXB13); ATAC-seq and RNA-seq integration; Perturbation experiments (siJUNB, T-5224, kinase inhibitors)

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Young fibroblasts exhibit synergistic gene expression enhancement to combined mechanical tension and TGF-β; aging cells show a blunted/divergent response
- Quantified transcriptional shifts: 2128 DE genes in young vs 391 DE genes in old under dual stimulation
- AP-1 motifs are enriched in age- and TGF-β-responsive chromatin regions (DACRs)
- AP-1 partner usage is age-dependent: JUNB in young cells, HOXB13 in old cells
- Disruption of AP-1 (siJUNB or T-5224) suppresses TGF-β–mediated induction of α-SMA and COL1A1
- AP-1 recruitment to RNA Pol II is modulated by upstream kinases; JNK/p38/PI3K influence recruitment, ERK affects post-recruitment potency

QC result: Pass.

331: Bi-allelic NDUFA5 variants and complex I mitochondriopathy

Gustavo Barra — Tue, 31 Mar 2026 07:28:12 +0000

Tan et al et al., The American Journal of Human Genetics - This report identifies bi-allelic NDUFA5 variants in four individuals from three families causing an isolated mitochondrial complex I deficiency with variable multisystem features. The study combines genomic, transcriptomic, proteomic, biochemical, structural modeling, and zebrafish functional data to support pathogenicity. Key terms: NDUFA5, complex I deficiency, mitochondriopathy, proteomics, zebrafish model.

Study Highlights:
Bi-allelic NDUFA5 variants were found in four individuals from three unrelated families presenting with a variable multisystem phenotype including congenital heart defects, hematological abnormalities, and Leigh-like neurological features. Multi-tissue RNA-seq and RT-PCR revealed aberrant splicing and NMD, while proteomics and BN-PAGE demonstrated reduced NDUFA5 protein, isolated complex I deficiency, and stalled assembly at a Q/P intermediate. CRISPR-Cas9 ndufa5 zebrafish crispants showed developmental delays, locomotor deficits, reduced survival, and epileptiform neural activity, corroborating functional impact.

Conclusion:
Combined clinical, molecular, and animal-model evidence supports that bi-allelic NDUFA5 variants cause a recessive mitochondriopathy with isolated complex I deficiency and variable multisystem involvement; NDUFA5 should be considered in molecular reanalysis of undiagnosed complex I disorders.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Bi-allelic variants in NDUFA5 cause a mitochondriopathy with complex I deficiency

First author:
Tan et al

Journal:
The American Journal of Human Genetics

DOI:
10.1016/j.ajhg.2026.03.003

Reference:
Tan et al., 2026, The American Journal of Human Genetics 113, 1–14, May 7, 2026. https://doi.org/10.1016/j.ajhg.2026.03.003

License:
CC BY (http://creativecommons.org/licenses/by/4.0/)

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/ndufa5-complex-i-mitochondriopathy

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-03-31.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript portions describing NDUFA5 variants, splicing consequences, proteomics/BN-PAGE findings, zebrafish model outcomes, and the diagnostic paradigm shift.
- transcript topics: Complex I biology and mitochondrial energy metabolism; Gene discovery via GeneMatcher and patient cohorts; NDUFA5 variant classes and their consequences; RNA sequencing and exon skipping due to synonymous variant; Protein abundance and complex I assembly defects; Blue native PAGE and assembly intermediates

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Bi-allelic NDUFA5 variants cause a mitochondrial complex I deficiency with multisystem disease
- Two distinct variant classes observed: frameshift + missense in Family 1; start-loss + synonymous splice variant in Family 2; homozygous synonymous splice variant in Family 3
- RNA-seq reveals aberrant splicing and nonsense-mediated decay for some alleles; exon 3 skipping yields a 39-amino-acid in-frame deletion
- Proteomics shows markedly reduced complex I abundance and undetectable NDUFA5 in affected individuals
- BN-PAGE shows assembly stall at the Q/P intermediately, with accumulation of specific subassemblies
- Zebrafish ndufa5 crispr mutants display developmental defects, locomotor impairment, seizures, and reduced survival

QC result: Pass.

330: 5ULTRA: Mapping 5′ UTR variants that alter protein translation

Gustavo Barra — Mon, 30 Mar 2026 06:50:35 +0000

Chaldebas M et al., The American Journal of Human Genetics - Chaldebas et al. present 5ULTRA, a computational pipeline that integrates uORF databases, Kozak-motif features, splicing prediction, and a random-forest score to detect and prioritize 5′ UTR variants predicted to alter protein translation. The score correlates with proteomic and MPRA measures and is applied to population, somatic, GWAS, and rare-disease datasets to nominate candidate functional variants. Key terms: 5' UTR, uORF, Kozak motif, translation regulation, machine learning.

Study Highlights:
The authors developed 5ULTRA to annotate SNVs, indels, and splicing variants that create/disrupt uORFs or alter Kozak strength, integrating comprehensive uORF databases and SpliceAI. A random-forest 5ULTRA score trained on HGMD and gnomAD distinguishes likely translation-impacting variants and achieved strong cross-validation performance and AUC = 0.82 on an independent ClinVar test. The score correlates with cis-pQTL effect sizes (Spearman rho = 0.57) and with MPRA ribosome-load measurements (rho = 0.78). Genome-wide screening found thousands of candidate variants, highlighted rare/conserved signals in disease genes, and nominated examples in cancer, GWAS loci, and rare infections.

Conclusion:
5ULTRA provides a validated, transcript-aware framework to detect and prioritize 5′ UTR variants that modulate translation, offering mechanistic hypotheses for noncoding variant interpretation in rare disease, cancer, and complex-trait genetics; the tool and data are publicly available under a CC BY license.

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-03-30.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Substantive auditing focused on the scientific content described in the transcript and its alignment with the AJHG article: 5ULTRA architecture, features, SpliceAI integration, validation metrics, somatic/GWAS/infectious disease applications, limitations, and open-source availability.
- transcript topics: 5′ UTR regulatory elements (Kozak motif, uORFs) and translation initiation; 5ULTRA methodology and data integration (MANE transcripts, uORFdb, Ribo-uORF, SpliceAI); Machine-learning scoring (17 features; PhyloP conservation as key predictor; uORF/k Kozak annotations); Model validation (ClinVar, cross-validation AUC, accuracy); Correlation with proteomics and MPRA data (cis-pQTL, ΔMRL); Somatic cancer applications (NRAS and ABI1 examples; splicing effects; N-terminal extensions)

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- 5ULTRA identifes and prioritizes 5′ UTR variants that affect translation via uORFs and Kozak motifs
- 17 features used by the 5ULTRA random forest model; PhyloP conservation of uORF start codon as the strongest predictor
- Genome-wide analysis: ~28 million 5′ UTR variants; ~137k predicted to affect translation via URFs or Kozak changes
- ClinVar independent test AUC ≈ 0.82 and ClinVar threshold-based accuracy ≈ 80.8%
- Cross-validation 5-fold AUC ≈ 0.981; MPRA and pQTL data show concordant translation effects (ΔMRL, Spearman ρ values ~0.78; 5ULTRA vs cis-pQTL ρ ≈ 0.57)

QC result: Pass.

Chapters

(00:00:08) - Genome Wide Detection of Human 5 UTR Variants
(00:06:41) - How a Deep Learning Algorithm Can Identify Dangerous Human Variants
(00:12:35) - 5 Ultra: The computational genetics of cancer
(00:18:46) - How to decode the secrets of the human genome

329: Large future genetic diversity losses predicted despite habitat protection

Gustavo Barra — Mon, 30 Mar 2026 06:04:15 +0000

Mualim KS et al., Proceedings of the National Academy of Sciences - This study develops spatiotemporal population-genetic models calibrated with genomic data to predict how habitat loss and fragmentation drive changes in nucleotide diversity (π). The authors translate IUCN, Living Planet Index, and GBF indicators into estimates of current and future genetic diversity loss across thousands of species. Key terms: genetic diversity, habitat loss, fragmentation, WFmoments, conservation indicators.

Study Highlights:
The authors built WFmoments and SLiM-based spatiotemporal frameworks and calibrated them with population-scale genomic data from 29 species to model π dynamics after habitat loss. They translated demographic proxies from the IUCN Red List, Living Planet Index, and GBF indicators for 4,611 species to estimate genetic diversity declines. Short-term π loss is often modest, but mid- and long-term losses lag behind habitat declines and can be substantially larger, with average estimates ranging from ~1–13% already lost and mid-term projections much higher under some datasets. Habitat fragmentation can inflate species-wide π while reducing within-population diversity, and recovery of genetic diversity after restoration is slow.

Conclusion:
Habitat protection alone is insufficient to guarantee long-term genetic health; conservation should incorporate genetic monitoring, connectivity restoration, and policies informed by spatiotemporal genetic forecasts.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Large future genetic diversity losses are predicted from conservation indicators even with habitat protection

First author:
Mualim KS

Journal:
Proceedings of the National Academy of Sciences

DOI:
10.1073/pnas.2514371123

Reference:
Mualim KS, Spence JP, Weiß C, Selmoni O, Lin M, Exposito-Alonso M. Large future genetic diversity losses are predicted from conservation indicators even with habitat protection. Proc. Natl. Acad. Sci. U.S.A. 2026. doi:10.1073/pnas.2514371123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/predicting-genetic-diversity-losses-329

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-03-30.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript’s coverage of the article’s methods (WFmoments, GDAR), habitat-loss scenarios (edge contraction vs fragmentation), key results (short-term vs long-term π losses, wallund/Wahlund effect), real-world examples (Miami Blue Butterfly, Torrey Pine, E. melliodora), and global-scale predictions; excluded
- transcript topics: Genetic diversity concept (π) and proxies; WFmoments framework and GDAR; Edge contraction vs fragmentation habitat-loss patterns; Wahlund/Wahlund-like effects and fragmentation inflation; Spatial population structure (FST) and migration; Empirical calibration: 29 species and 4,611 species predictions

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Short-term π diversity loss after habitat loss is 1–13% (GDAR/π dynamics).
- Long-term π diversity loss lags behind habitat loss and depends on population structure; strongly structured populations show about 27% long-term loss after 50% habitat loss.
- Fragmentation can inflate species-wide π diversity due to the Wahlund effect, with increases up to about 263%.
- Within-population diversity (πlocal) declines under fragmentation, even when species-wide π appears elevated.
- Genetic diversity recovery after habitat restoration is slow and may take thousands to millions of generations; restoration does not rapidly rebuild lost genetic codes.
- Miami Blue Butterfly example predicts mid-term genetic collapse in about 12.5 years (given specific population parameters).

QC result: Pass.

328: Variant selection boosts R2 for haptoglobin (HP) in cis‑Mendelian randomization

Gustavo Barra — Fri, 27 Mar 2026 08:32:26 +0000

Zhou A et al., Human Genetics and Genomics Advances - Comparing LD‑pruning, COJO, SuSiE and PCA in haptoglobin (HP) cis‑region data, the study finds including non‑lead variants substantially increases variance explained (R2) and MR precision. Key terms: haptoglobin, cis-Mendelian randomization, LD-pruning, SuSiE, COJO.

Study Highlights:
The study analyzed circulating haptoglobin (HP) using Fenland protein GWAS summary statistics with LD from UK Biobank, compared four variant selection methods (modified LD‑pruning, COJO, SuSiE, PCA), and extended results with simulations and 15 additional gene regions. In the HP region, incorporating non‑lead variants produced a median proportional gain in R2 of 145.1% and a median reduction in MR standard error of 36.3% relative to the lead variant alone. In simulations with one or two causal variants the methods recovered the expected genetic variance (≈40%) and, when causal variants were removed, non‑lead‑inclusive methods recovered more variance than lead‑only. The functional implication supported by the data is that including correlated non‑lead variants can materially increase instrument strength and precision in cis‑MR, but may raise risks of pleiotropy and numerical instability.

Conclusion:
Variant selection methods that incorporate correlated non‑lead variants reliably improve instrument strength (R2) and MR precision in cis‑MR compared with the lead‑variant‑only approach; comparisons with the lead variant are advised to detect instability.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Variant selection to maximize variance explained in cis-Mendelian randomization

First author:
Zhou A

Journal:
Human Genetics and Genomics Advances

DOI:
10.1016/j.xhgg.2026.100573

Reference:
Zhou A, Karhunen V, Tian H, Pott J, Patel A, Slob EAW, Burgess S. Variant selection to maximize variance explained in cis-Mendelian randomization. Human Genetics and Genomics Advances. 2026 Apr 9;7:100573. https://doi.org/10.1016/j.xhgg.2026.100573.

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/hp-variant-selection-cis-mr

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-03-27.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript sections describing: (1) the four variant selection methods and their rationale; (2) HP region results including R2 gains and SE reductions; (3) simulation studies with known causal variance (40%); (4) extension to 15 gene regions; (5) pleiotropy concerns and safeguards; (6) practical recommendat
- transcript topics: Four variant selection methods (LD-pruning, COJO, SuSiE, PCA); Modified LD-pruning with adjusted R2 and LD-matrix checks; HP region results: variance explained (R2) gains and MR precision; Simulations with known causal variance (40%); Two-causal-variant scenario and lead variant variance explained; Extension to 15 additional gene regions

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Variant selection methods tested: LD-pruning, COJO, SuSiE, and PCA
- HP region results: median proportional gain in R2 of 145.1% and median MR SE reduction of 36.3%
- Simulations recovered about 40% variance explained across methods
- Across 15 gene regions, non-lead variant methods outperformed lead-variant-only approach
- Recommendation to compare multivariant estimates with lead-variant-only baseline
- ABO locus cited as a pleiotropy risk example

QC result: Pass.

327: Bi-allelic ATG12 variants impair ATG12-ATG5 conjugation, LC3 lipidation and neural development

Gustavo Barra — Fri, 27 Mar 2026 08:22:44 +0000

Lambton J et al., The American Journal of Human Genetics - Bi-allelic ATG12 variants disrupt ATG12‑ATG5 conjugation and LC3 lipidation, impairing autophagy in patient cells and model systems and causing cerebellar vermis hypoplasia. Key terms: ATG12, autophagy, neurodevelopmental disorder, zebrafish, LC3 lipidation.

Study Highlights:
The study characterized six affected individuals with bi-allelic ATG12 variants using patient fibroblasts, HeLa ATG12 knockout complementation, yeast complementation, and CRISPR zebrafish models. Methods included WES/WGS and Sanger sequencing, immunoblotting, LC3/p62 flux assays, HaloTag-LC3 processing, LDH sequestration, AlphaFold-Multimer structural modeling, yeast GFP-Atg8 assays, and zebrafish behavioral and imaging assays. Structural modeling and biochemical data indicate variants map to ATG12 interfaces with ATG5 and ATG3, destabilize ATG12 or its conjugate with ATG5, reduce LC3/Atg8 lipidation and autophagic flux in a variant-dependent manner. Functionally, ATG12 disruption associates with neurodevelopmental phenotypes including cerebellar vermis hypoplasia, ataxia and seizures in humans, and causes growth, brain-structure and locomotor defects with reduced survival in zebrafish.

Conclusion:
Bi-allelic ATG12 variants impair ATG12 function and autophagy, producing a recessive neurodevelopmental disorder marked by cerebellar vermis hypoplasia and neurological deficits.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Bi-allelic ATG12 variants impair autophagy and cause a neurodevelopmental disorder

First author:
Lambton J

Journal:
The American Journal of Human Genetics

DOI:
10.1016/j.ajhg.2026.03.002

Reference:
Lambton J, Asano S, Huang Y, Suomi F, Eguchi T, Petree C, Huang K, Prigent M, Imam A, McCorvie TJ, Warren D, Hobson E, McCullagh H, Misceo D, Bjerre A, Smeland MF, Klingenberg C, Frengen E, Naik S, Ryan G, Sudarsanam A, Foster K, Vasudevan P, Samanta R, Rahman F, Maqbool S, Udani V, Efthymiou S, Houlden H, McFarland R, Collier JJ, Maroofian R, Yue WW, Varshney GK, Klionsky DJ, Legouis R, McWilliams TG, Mizushima N, Oláhová M, Alston CL, Taylor RW. Bi-allelic ATG12 variants impair autophagy and cause a neurodevelopmental disorder. The American Journal of Human Genetics. 2026 May 7;113:1–18. https://doi.org/10.1016/j.ajhg.2026.03.002

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/biallelic-atg12-autophagy-disorder

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-03-27.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited substantive scientific content from the transcript, focusing on the patient cohort, molecular mechanism (ATG12-ATG5 conjugation, LC3 lipidation), structural modeling, model organisms (yeast, zebrafish), and neurological phenotype.
- transcript topics: Bi-allelic ATG12 variants and patient cohort; ATG12-ATG5 conjugation and LC3 lipidation; AlphaFold/structural modeling of ATG12 interactions; Yeast and zebrafish functional assays; Cerebellar involvement and mitophagy; Therapeutic implications of autophagy modulation

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Six individuals from five unrelated families with bi-allelic ATG12 variants were described.
- ATG12-ATG5 conjugate loss was observed in one family (S2) and an intact conjugate in another (S3).
- Autophagy flux was altered in subject-derived cells under starvation conditions.
- Zebrafish atg12 knockout showed developmental delay, brain defects, reduced locomotion, and pre-adult lethality.
- Yeast complementation showed hypomorphic, partial-function ATG12 variants; AlphaFold-Multimer modeling placed variants near ATG12 interfaces with ATG5/ATG3.
- Cerebellar vermis hypoplasia and related neurodevelopmental phenotypes were highlighted as key clinical features.

QC result: Pass.

326: DUO-1 protects REC-8 cohesin and synaptonemal complex stability in Caenorhabditis elegans meiosis

Gustavo Barra — Wed, 25 Mar 2026 22:58:07 +0000

Strand LG et al., Proc. Natl. Acad. Sci. U.S.A - In C. elegans germline, the deubiquitinase DUO-1 is required for assembly and active maintenance of the synaptonemal complex and REC-8 cohesin, preventing RAD-51 accumulation and ensuring diakinesis compaction. Key terms: DUO-1, Caenorhabditis elegans, synaptonemal complex, REC-8, auxin-inducible degron.

Study Highlights:
Using C. elegans germline as a developmental timecourse model, the authors combined cytological analyses (immunofluorescence, FISH, RAD-51/MSH-5/COSA-1 staining), temporally controlled auxin-inducible degron (AID) depletion, and TurboID proximity labeling with LC–MS to probe DUO-1 function. Loss or acute depletion of DUO-1 impairs SC assembly, leads to progressive axis/SC instability, depletion of REC-8 cohesin from chromosomes, hyperaccumulation of RAD-51-marked early DSB repair intermediates, and premature sister-chromatid separation. TurboID identifies PARG-1 and cohesin/HORMAD components as proximal partners and DUO-1::GFP localizes to nucleoplasm and a subset of chromosome axes, most prominently in late pachytene/early diplotene. Temporal AID experiments show DUO-1 is required continuously for early SC assembly, late-pachytene SC maintenance, and rapid preservation of diakinesis chromosome compaction, implying an active maintenance role for DUO-1 in preserving chromosome architecture during meiotic prophase.

Conclusion:
DUO-1 is continuously required throughout meiotic prophase in C. elegans to promote assembly and maintain stability of chromosome axes and synaptonemal complexes, protect REC-8 cohesin distribution, limit accumulation of early DSB repair intermediates, and ensure late-prophase chromosome compaction.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Active maintenance of meiosis-specific chromosome structures in Caenorhabditis elegans by the deubiquitinase DUO-1

First author:
Strand LG

Journal:
Proc. Natl. Acad. Sci. U.S.A

DOI:
10.1073/pnas.2532671123

Reference:
Strand LG, Choi CP, McCoy S, Nsamba ET, Silva N, Villeneuve AM. Active maintenance of meiosis-specific chromosome structures in Caenorhabditis elegans by the deubiquitinase DUO-1. Proc. Natl. Acad. Sci. U.S.A. 2026;123(12):e2532671123. https://doi.org/10.1073/pnas.2532671123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/duo-1-c-elegans-meiosis

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-03-25.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the spoken scientific content reflecting the paper's core findings: DUO-1’s continuous maintenance of meiosis-specific chromosome structures, SC/axis stability, REC-8 cohesin protection, RAD-51 dynamics, AID-time course revealing separable roles, and the DUO-1–PARG-1 interaction revealed by TurboID.
- transcript topics: Meiotic prophase architecture (SC/axis) and DUO-1 roles; Duo-1 mutant phenotypes: SC assembly failure and polycomplexes; REC-8 cohesin distribution and sister chromatid cohesion; RAD-51 dynamics and SPO-11 dependency; COSA-1 foci and recombination intermediates; Auxin-inducible degradation (AID) reveals separable roles in assembly, maintenance, and compaction

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- DUO-1 is continually required throughout meiotic prophase to promote axis/SC assembly, maintain axis/SC stability, and promote/maintain chromosome compaction by the end of prophase
- Duo-1 mutants show impaired SC assembly and polycomplex formation; REC-8 cohesin distribution is lost as SCs disassemble
- RAD-51 foci hyperaccumulate in duo-1 mutants in a SPO-11–dependent manner
- Auxin-inducible degradation (AID) of DUO-1 reveals separable roles in SC assembly (early prophase), maintenance (late pachytene), and chromosomal compaction (diakinesis)
- TurboID proximity labeling identifies DUO-1 near PARG-1 and axis components; PARG-1 localization is impaired in duo-1 mutants but enzymatic activity persists and PAR does not accum
- DUO-1 is a deubiquitinase that protects cohesin/axis components from ubiquitin-mediated turnover

QC result: Pass.

325: cis-pcQTL mapping reveals allelic proxitropy across neighboring human genes

Gustavo Barra — Tue, 24 Mar 2026 08:03:54 +0000

Lawrence et al., The American Journal of Human Genetics - Using a cis-principal-component (pcQTL) approach in human GTEx tissues, the authors uncover novel multi-gene regulatory variants and 33% more GWAS colocalizations than single-gene eQTLs. Key terms: pcQTL, allelic proxitropy, GTEx, colocalization, HOXB.

Study Highlights:
The study analyzes 13 human GTEx tissues and identifies clusters of co-expressed neighboring genes, then applies PCA to cluster expression and maps cis-principal-component QTLs (pcQTLs). pcQTL discovery and fine-mapping used SuSiE and TensorQTL permutation-based FDR to identify an average of ~1,396 pcQTLs per tissue, ~27% of which were not found by single-gene eQTL mapping. pcQTLs tend to represent smaller effects distributed across multiple genes in a cluster and often colocalize with GWAS hits missed by single-gene methods. Functionally, pcQTLs increased GWAS colocalizations by 33%, highlighting multi-gene regulatory proxitropy as a source of complex-trait-associated variation.

Conclusion:
Cis-multi-gene pcQTL mapping uncovers novel regulatory loci and increases GWAS colocalizations compared with single-gene analyses, demonstrating that multi-gene approaches improve detection and interpretation of complex-trait-associated variants.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Focus on single-gene effects limits discovery and interpretation of complex-trait-associated variants

First author:
Lawrence

Journal:
The American Journal of Human Genetics

DOI:
10.1016/j.ajhg.2026.02.022

Reference:
Lawrence, K.A., Gjorgjieva, T., Nachun, D., and Montgomery, S.B. (2026). Focus on single-gene effects limits discovery and interpretation of complex-trait-associated variants. The American Journal of Human Genetics 113, 1–10. https://doi.org/10.1016/j.ajhg.2026.02.022

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/cis-pcqtl-allelic-proxitropy-gtex

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-03-24.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript sections presenting the conceptual shift to neighborhood gene regulation (allelic proxytropy), the cis-pcQTL (pcQTL) methodology, GTEx tissue clustering, key quantitative results (novel pcQTLs, clusters, colocalizations), and concrete examples (HOXB cluster, IL-18 receptor genes), plus discussion
- transcript topics: Conceptual shift to gene neighborhoods and allelic proxytropy; cis-pcQTL (pcQTL) methodology and PCA-based signal extraction; GTEx tissue clusters and gene-neighborhood calling; pcQTL discovery statistics (clusters, pcQTLs per tissue, novel signals); pcQTLs and GWAS colocalizations; HOXB cluster example (HOXB3 vs HOXB4) and PC4

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- pcQTLs reveal novel multi-gene regulatory variants missed by single-gene eQTLs
- average pcQTLs per tissue is 1,396
-...

Chapters

(00:00:00) - Deep Dive: The genome's interconnected networks
(00:05:27) - The Shared Signal of Genomic Science
(00:11:15) - Single gene mapping fails to explain complex traits
(00:18:13) - Understanding the genetics of human diseases
(00:20:39) - Beyond one gene

324: ZSWIM8–CUL3 clamp on AGO2–miR-7 reveals mechanism of targeted microRNA degradation

Gustavo Barra — Mon, 23 Mar 2026 05:43:07 +0000

Farnung J et al., Nature - Cryo-EM and biochemical reconstitution reveal how the ZSWIM8–CUL3 E3 ligase recognizes human AGO2–miRNA–trigger complexes to polyubiquitylate AGO and drive targeted microRNA degradation. Key terms: ZSWIM8, AGO2, target-directed miRNA degradation, cryo-EM structure, E3 ubiquitin ligase.

Study Highlights:
Using purified human proteins and cellular assays, the authors combined cryo-EM (3.1 Å), in vitro ubiquitylation, co-immunoprecipitation and sRNA-seq to dissect TDMD. Cryo-EM shows a dimeric ZSWIM8 that forms an asymmetric clamp around AGO2–miR-7–CYRANO, engaging the MID, N and PAZ domains and embracing trigger RNA flanks. Biochemical reconstitution demonstrates that ZSWIM8–CUL3 together with ARIH1 polyubiquitylates surface lysines of AGO only when the miRNA is paired to a trigger that vacates the PAZ pocket and imposes a specific RNA trajectory. Functionally, these multivalent RNA–RNA, RNA–protein and protein–protein interactions establish a two-RNA-factor authentication mechanism that explains TDMD selectivity and indicates ZSWIM8 can destabilize extensively trimmed miRNAs.

Conclusion:
ZSWIM8–CUL3 recognizes a trigger-induced AGO–miRNA conformation via multivalent interactions—including sensing a vacated PAZ pocket and flanking trigger RNA—to direct ARIH1-dependent polyubiquitylation of AGO and execute TDMD.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
The E3 ubiquitin ligase mechanism specifying targeted microRNA degradation

First author:
Farnung J

Journal:
Nature

DOI:
10.1038/s41586-026-10232-0

Reference:
Farnung J., Slobodyanyuk E., Wang P.Y., Blodgett L.W., Lin D.H., von Gronau S., Schulman B.A. & Bartel D.P. The E3 ubiquitin ligase mechanism specifying targeted microRNA degradation. Nature (2026). https://doi.org/10.1038/s41586-026-10232-0

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/zswim8-cul3-tdmd-structure

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-03-23.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript portions describing TDMD mechanism, ZSWIM8–CUL3 E3 ligase architecture, AGO2–miRNA–trigger complex recognition, CYRANO/HSUR1 triggers, RNA flanking regions and RBEs, PAZ-pocket vacancy, dimeric clamp, and broader biological implications.
- transcript topics: TDMD overview and cellular context; ZSWIM8–CUL3 E3 ligase architecture and dimer clamp; AGO2–miRNA–trigger complex recognition by ZSWIM8; Trigger RNAs (CYRANO, HSUR1) and pairing architecture; RNA flanking regions and RBEs in ZSWIM8 binding; PAZ pocket vacancy and RNA trajectory

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- TDMD is mediated by ZSWIM8–CUL3 E3 ligase polyubiquitylating AGO2–miRNA in the presence of a trigger RNA
- ZSWIM8 preferentially binds AGO–miRNA–trigger ternaries over AGO–miRNA–seed-only complexes
- ZSWIM8 operates as a dimer that clamps around the AGO2–miR-7–CYRANO complex
- Trigger RNA-induced conformational changes expose an unoccupied PAZ pocket that is recognized by ZSWIM8
- RNA flanking regions and RBEs contribute to ZSWIM8 recognition and binding efficiency
- Two-RNA-factor authentication model: miRNA as password, trigger RNA as phone ping

QC result: Pass.

323: Meat consumption and APOE ε3/ε4–ε4/ε4: slower cognitive decline and lower dementia risk in SNAC‑K

Gustavo Barra — Sun, 22 Mar 2026 13:11:34 +0000

Norgren J et al., JAMA Network Open - Population-based SNAC-K study finds higher meat consumption associated with slower cognitive decline and lower dementia risk in APOE ε3/ε4 and ε4/ε4 older adults. Key terms: APOE4, meat consumption, dementia, episodic memory, SNAC-K.

Study Highlights:
Using the Swedish National Study on Aging and Care–Kungsholmen (SNAC-K) cohort of older adults and repeated validated food-frequency questionnaires, the authors applied panel data analyses with linear regression for cognitive trajectories and Fine and Gray models for dementia incidence. Higher total meat consumption (top vs bottom quintile) in APOE ε3/ε4 and ε4/ε4 participants was associated with better 10-year global cognitive trajectories (β = 0.32) and lower dementia risk (sHR = 0.45). The processed-to-total meat ratio was associated with higher dementia risk (sHR = 1.14) without APOE interaction. Post hoc vitamin B12 analyses suggested APOE-specific differences in nutrient uptake that could help explain the genotype-specific associations.

Conclusion:
Higher meat consumption was associated with slower cognitive decline and reduced dementia incidence among APOE ε3/ε4 and ε4/ε4 carriers, such that the expected excess risk in these genotypes was not observed at high intake levels.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Meat Consumption and Cognitive Health by APOE Genotype

First author:
Norgren J

Journal:
JAMA Network Open

DOI:
10.1001/jamanetworkopen.2026.6489

Reference:
Norgren J, Carballo-Casla A, Grande G, et al. Meat Consumption and Cognitive Health by APOE Genotype. JAMA Network Open. 2026;9(3):e266489. https://doi.org/10.1001/jamanetworkopen.2026.6489

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/meat-apoe34-44-cognition

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-03-22.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript’s representation of the paper’s core scientific claims: APOE4 carriers (APOE34/44) show cognitive benefits and reduced dementia risk with higher meat intake; non-APOE34/44 show no such association; processed meat increases dementia risk; unprocessed meat associates with lower mortality in APOE34/
- transcript topics: APOE gene and Alzheimer's risk; APOE4 vs APOE3/2 evolution and dietary adaptation; SNAC-K cohort design, dietary assessment, and cognitive outcomes; Total meat intake and cognitive trajectories by APOE genotype; Dementia incidence by APOE genotype and meat quintiles; Processed-to-total meat ratio and dementia risk

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- APOE34/44 carriers show improved cognitive trajectories and reduced dementia risk with higher meat intake (top quintile) compared with bottom quintile.
- Cognition and dementia benefits for APOE34/44 are quantified as β = 0.32 (P = .01) and sHR = 0.45 (P = .04) respectively.
- No cognitive or dementia associations with meat intake in non-APOE34/44 genotypes (APOE22/23/24/33).
- A higher processed-to-total meat ratio is unfavorably associated with dementia (sHR = 1.14; P = .04) with no APOE interaction.
- Post hoc analyses: unprocessed meat linked to lower all-cause mortality in APOE34/44 (HR = 0.85; P = .04; P for interaction = .03).
- Vitamin B12 absorption differences via food matrix proposed as a mechanism; APOE4 may absorb more from meat matrix than from other sources.

QC result: Pass.

322: Bi-allelic RNU6ATAC and RNU4ATAC variants cause infancy-onset autoimmune diabetes via minor spliceosome U12 intron retention

Gustavo Barra — Sun, 22 Mar 2026 07:13:33 +0000

Johnson MB et al., The American Journal of Human Genetics - Bi-allelic variants in snRNAs RNU6ATAC and RNU4ATAC cause infancy-onset autoimmune diabetes in humans, with RNA-seq showing U12 intron retention and impaired B cell development. Key terms: RNU6ATAC, RNU4ATAC, minor spliceosome, U12 intron retention, autoimmune diabetes.

Study Highlights:
In human infants with early-onset diabetes and immune dysregulation, the authors used genome sequencing, RNA-seq, DNA methylation deconvolution, WGCNA, Sanger sequencing, and flow cytometry to define a genetic syndrome. They identified 19 individuals with bi-allelic RNU6ATAC or RNU4ATAC variants and RNA-seq revealed significant U12 intron retention in 274 genes, 94% of which are known U12-intron-containing genes. Multi-omic analyses and targeted immune profiling showed reduced naive B cells and abnormal B cell maturation. Half of tested individuals were GADA-positive, supporting an autoimmune mechanism for the diabetes in these snRNA spliceosome disorders.

Conclusion:
Bi-allelic pathogenic variants in RNU6ATAC cause early-onset autoimmune diabetes with immune dysregulation and bi-allelic RNU4ATAC variants extend RNU4ATAC-opathy to include infancy-onset autoimmune diabetes.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Bi-allelic variants in the non-protein-coding minor spliceosome components RNU6ATAC and RNU4ATAC cause syndromic monogenic autoimmune diabetes

First author:
Johnson MB

Journal:
The American Journal of Human Genetics

DOI:
10.1016/j.ajhg.2026.02.017

Reference:
Johnson MB, Russ-Silsby J, Blair PA, Govier M, Bonfield G, Domingo-Vila C, EXE-T1D consortium, ATAC clinical consortium, Wakeling MN, Oram RA, Flanagan SE, Tree TIM, Patel KA, Hattersley AT, De Franco E. Bi-allelic variants in the non-protein-coding minor spliceosome components RNU6ATAC and RNU4ATAC cause syndromic monogenic autoimmune diabetes. The American Journal of Human Genetics. 2026 Apr 2;113:1–11. https://doi.org/10.1016/j.ajhg.2026.02.017

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/rnu6atac-rnu4atac-minor-spliceosome

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-03-22.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript portions describing (a) minor spliceosome biology and snRNA function, (b) genetic findings in RNU6ATAC and RNU4ATAC, (c) U12 intron retention as a shared mechanism, (d) B cell development impairment and multi-omic immune profiling, (e) autoimmunity evidence (GADA positivity), (f) clinical phenoty
- transcript topics: Minor spliceosome biology and U12 introns; RNU6ATAC bi-allelic variants; RNU4ATAC bi-allelic variants and interaction with RNU6ATAC; RNA-seq intron retention in U12 genes; B cell development and maturation defects; Islet autoantibody positivity in early-onset diabetes

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- 19 individuals from 16 families with bi-allelic variants in RNU6ATAC or RNU4ATAC
- RNA-seq shows U12 intron retention in 274 genes (274/258 known U12 genes; 94% overlap with IAOD)
- 50% of tested individuals were GADA-positive
- Reduced naive B cells and impaired B cell maturation validated by DNA methylation deconvolution and flow cytometry
- Infancy-onset insulin-dependent diabetes (median onset ~17–20 weeks)

QC result: Pass.

321: All five canonical nucleobases detected in Ryugu samples

Gustavo Barra — Fri, 20 Mar 2026 23:52:05 +0000

Koga T et al., Nature Astronomy - Ryugu asteroid samples analyzed by HPLC/ESI-HRMS reveal all five canonical nucleobases (adenine, guanine, cytosine, thymine, uracil) and distribution linked to ammonia. Key terms: Ryugu, nucleobases, adenine, HPLC/ESI-HRMS, purine-to-pyrimidine ratio.

Study Highlights:
The team analysed Ryugu aggregate samples A0480 and C0370 and the Orgueil meteorite using water and HCl extraction followed by HPLC/ESI-HRMS, CE-HRMS and nano-EA/IRMS. They identified all five canonical nucleobases and measured total nucleobase concentrations (C0370 = 1,577 pmol g−1) and purine-to-pyrimidine (Pu/Py) ratios of ~1.1–1.2 in Ryugu contrasted with 0.099 in Orgueil and 3.4 in Murchison. A strong negative correlation (R2=0.89) between Pu/Py ratios and ammonia across Ryugu, Bennu and Orgueil implies ammonia availability influenced nucleobase formation pathways. The results support widespread abiotic nucleobase synthesis in carbonaceous parent bodies and potential delivery of diverse prebiotic molecules to early Earth.

Conclusion:
All five canonical nucleobases are present in Ryugu samples and their purine-to-pyrimidine distributions, which correlate with ammonia, indicate shared but environment-dependent formation pathways on carbonaceous parent bodies.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
A complete set of canonical nucleobases in the carbonaceous asteroid (162173) Ryugu

First author:
Koga T

Journal:
Nature Astronomy

DOI:
10.1038/s41550-026-02791-z

Reference:
Koga T., Ogawa N. O., Ohkouchi N., Oba Y., Takano Y., Naraoka H., Sasaki K., Sato H., Yoshimura T. et al. A complete set of canonical nucleobases in the carbonaceous asteroid (162173) Ryugu. Nature Astronomy (2026). https://doi.org/10.1038/s41550-026-02791-z

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/ryugu-nucleobases-ammonia-correlation

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-03-20.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited transcript sections presenting nucleobase detection, extraction/analytical workflow, concentration data for Ryugu samples, Pu/Py ratios across samples, ammonia correlation, abiotic/isomer evidence (6-methyluracil, hypoxanthine isomer), Chargaff's rule discussion, isotopic signatures, contamination controls, and
- transcript topics: Detection of all five canonical nucleobases in Ryugu; Sequential extraction workflow (water then HCl) and analytical methods (HPLC/ESI-HRMS, CE-HRMS, nano-EA/IRMS); Concentrations of nucleobases in Ryugu samples A0480 and C0370; comparison to Orgueil; Pu/Py (purine/pyrimidine) ratios across Ryugu, Bennu, Orgueil, and Murchison; Correlation between Pu/Py ratios and ammonia concentrations; Evidence for abiotic nucleobase formation: non-biological isomers (6-methyluracil) and hypoxanthine isomer

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- All five canonical nucleobases detected in Ryugu samples A0480 and C0370 (adenine, guanine, cytosine, thymine, uracil).
- Total nucleobase concentration in C0370: 1577 ± 35 pmol g−1; in A0480: 507 ± 21 pmol g−1.
- Pu/Py ratios: Ryugu A0480 ≈ 1.1–1.2; Ryugu C0370 ≈ 1.1–1.2; Orgueil ≈ 0.099; Bennu ≈ 0.55; Murchison ≈ 3.4.
- Pu/Py ratio negatively correlates with ammonia across Ryugu, Bennu, Orgueil (R2 ≈ 0.89).
- Detection of non-biological isomers (e.g., 6-methyluracil) and an hypoxanthine isomer.
- Isotopic signatures show heavy isotopes (δ13C and δ15N) in soluble components, supporting a space origin.

QC result: Pass.

320: Sex-stratified cQTL mapping identifies TOX (IFN-γ) and EGFR (IL-10) regulators in Dutch and Tanzanian cohorts

Gustavo Barra — Thu, 19 Mar 2026 06:18:37 +0000

Amour C et al., Human Genetics and Genomics Advances, Journal Pre-proof - Sex-stratified cQTL mapping in Tanzanian and Dutch adults identifies sex-specific regulators such as TOX-linked IFN-γ in males and EGFR-linked IL-10 in females, revealing multiple genome-wide cQTLs. Key terms: TOX, EGFR, cytokine QTL, sex-stratified GWAS, Tanzania-Netherlands.

Study Highlights:
The study analyzed cytokine production after ex vivo stimulation in two human cohorts (Tanzania 300TZFG and Dutch 500FG) using sex-stratified cytokine QTL mapping with linear models adjusted for cell counts and covariates. Genotyping, imputation, ELISA cytokine assays, colocalization (coloc) and SNP×sex interaction tests were applied to test sex-specific genetic effects. The authors report twelve genome-wide significant cQTLs in the Tanzanian cohort (seven male-specific, five female-specific) and twelve in the Dutch cohort with multiple sex-specific loci, highlighting TOX-associated IFN-γ regulation in males and EGFR-linked IL-10 regulation in females. These sex-specific autosomal effects altered which associations were detectable in pooled analyses, implying implications for sex-aware precision approaches to immune-related diseases.

Conclusion:
Sex-stratified autosomal analyses identify distinct genetic regulators of cytokine production, demonstrating that many cQTLs act in a sex-specific manner across Tanzanian and Dutch cohorts and can be missed by pooled analyses.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Sex-stratified genetic regulators of cytokine production in the Dutch and Tanzanian populations

First author:
Amour C

Journal:
Human Genetics and Genomics Advances, Journal Pre-proof

DOI:
10.1016/j.xhgg.2026.100593

Reference:
Amour C, Cetatean R, Ponce IR, Keur N, Temba GS, Kullaya VI, Mmbaga BT, Kavishe R, Joosten LAB, Netea MG, de Mast Q, Boahen CK, Kumar V, Sex-stratified genetic regulators of cytokine production in the Dutch and Tanzanian populations, Human Genetics and Genomics Advances (2026), doi: https://doi.org/10.1016/j.xhgg.2026.100593.

License:
Not specified in the provided text.

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/sex-stratified-cytokine-qtl

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-03-19.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript sections describing (1) Tanzanian cohort results (12 cQTLs; 7 male-specific, 5 female-specific), (2) Dutch cohort results (12 cQTLs; 6 male-specific, 6 female-specific), (3) exemplar sex-specific loci TOX (male IFN-γ) and EGFR (female IL-10), (4) CNTNAP2 and ANXA8 findings, (5) colocalization ana
- transcript topics: Sex differences in immune regulation and cytokine signaling; Cohort design: Tanzanian (TZ) and Dutch (NL) sex-stratified cQTL mapping; TOX locus and IFN-γ response in males (S. pneumoniae); EGFR locus and IL-10 response in females (C. burnetii); CNTNAP2 locus and IFN-γ response in females (M. tuberculosis).; ANXA8 locus and TNF-α response in females (C. albicans)

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Two cohorts: Tanzania TZFG and Netherlands 500FG (Dutch) with sex-stratified cQTL mapping
- Tanzanian cohort identified 12 genome-wide significant cQTLs (7 male-specific, 5 female-specific)
- Dutch cohort identified 12 genome-wide significant cQTLs (6 male-specific, 6 female-specific)
- TOX locus variant rs10092649 associated with IFN-γ production after S. pneumoniae stimulation in males
- EGFR-proximal locus rs79030770 associated with IL-10 production after C. burnetii stimulation in females
- CNTNAP2 locus variant rs17170577 associated with IFN-γ production after M. tuberculosis stimulation in females

QC result: Pass.

319: Predicting reduced-penetrance TP53 variants from functional assays and random forest models

Gustavo Barra — Wed, 18 Mar 2026 07:43:37 +0000

Fortuno C et al., Human Genetics and Genomics Advances - TP53 germline variant analysis using functional assays finds reduced-penetrance variants have intermediate activity, higher frequency, later onset, and 106 predicted candidates. Key terms: TP53, reduced penetrance, Li-Fraumeni syndrome, functional assays, variant interpretation.

Study Highlights:
Using ClinVar curation and comparison to benign and pathogenic reference sets, the authors analyzed TP53 germline variants with multiple functional assays, bioinformatic predictors, immune-fitness scores, and gnomAD frequencies. Reduced-penetrance variants tended to show intermediate activity across Kato, Giacomelli, Kotler, and Funk assays and intermediate BayesDel/AlphaMissense/aGVGD scores, with higher allele frequencies than pathogenic variants. A random forest model trained on these features prioritized 106 additional ClinVar missense variants as potential reduced-penetrance candidates. Clinically, carriers of reduced-penetrance variants exhibited later average age at first cancer and weaker enrichment for core Li-Fraumeni phenotypes, supporting consideration of attenuated surveillance criteria.

Conclusion:
Reported reduced-penetrance TP53 variants display intermediate functional and bioinformatic signatures, higher population frequency, and later cancer onset, and a combined-feature predictive model identifies additional candidate reduced-penetrance variants for follow-up.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Characteristics predicting reduced penetrance variants in the high-risk cancer predisposition gene TP53

First author:
Fortuno C

Journal:
Human Genetics and Genomics Advances

DOI:
10.1016/j.xhgg.2025.100484

Reference:
Fortuno C, Richardson ME, Pesaran T, McGoldrick K, James PA, Spurdle AB. Characteristics predicting reduced penetrance variants in the high-risk cancer predisposition gene TP53. Human Genetics and Genomics Advances. 2025;6:100484. https://doi.org/10.1016/j.xhgg.2025.100484

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/tp53-reduced-penetrance-prediction

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-03-18.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited sections describing TP53 reduced-penetrance variants, four functional assays (Kato, Giacomelli, Kotler, Funk), bioinformatic predictors (BayesDel, AlphaMissense, aGVGD), immune fitness, population allele frequency, a random forest model identifying additional candidates, and associated clinical implications.
- transcript topics: TP53 and Li-Fraumeni syndrome background; Functional assays (Kato, Giacomelli, Kotler, Funk); Bioinformatic predictors (BayesDel, AlphaMissense, aGVGD); Immune fitness predictions; Population allele frequency (gnomAD); Random forest model and variant prioritization

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Reduced penetrance TP53 variants show intermediate functional activity across four assays (Kato, Giacomelli, Kotler, Funk).
- Brazilian founder TP53 variant c.1010G>A (p.R337H) is discussed among the reduced penetrance set.
- Benign reference set (62 variants) and pathogenic reference set (113 variants) used for comparison; 11 reduced penetrance variants identified from ClinVar/other sources.
- Four functional assays (Kato, Giacomelli, Kotler, Funk) with intermediate results for reduced penetrance variants.
- Bioinformatic predictors (BayesDel, AlphaMissense, aGVGD) predict deleterious effects for reduced penetrance variants with lower scores than pathogenic variants.
- Immune fitness indicates intermediate visibility of reduced penetrance variants—between benign and pathogenic.

QC result: Pass.

318: RNU6ATAC variants cause U6atac-driven minor spliceopathy with transcriptome-wide minor intron retention

Gustavo Barra — Wed, 18 Mar 2026 07:31:55 +0000

Mendez R et al., Human Genetics and Genomics Advances, Journal Pre-proof - Biallelic RNU6ATAC variants disrupt the U6atac minor spliceosomal snRNA, causing transcriptome-wide minor intron retention and short stature with variable multisystem manifestations. Key terms: RNU6ATAC, U6atac, minor spliceosome, minor intron retention, whole-genome sequencing.

Study Highlights:
This study analyzed three unrelated human individuals using RNA-seq on whole-blood and fibroblasts and applied a FRASER-based minor intron retention (MIR) outlier pipeline alongside whole-genome sequencing. The integrated approach identified biallelic RNU6ATAC variants that map to U4atac–U6atac Stem I/II and the central stem-loop of U6atac. Affected individuals show transcriptome-wide excess MIR (for example A1 exhibited 254 MIR outliers in whole blood and B1 exhibited 16 MIR outliers in fibroblasts), indicating impaired minor spliceosome function. The molecular defect correlates with impaired growth and variable multisystem phenotypes including immunodeficiency and neurodevelopmental involvement.

Conclusion:
Biallelic RNU6ATAC variants cause a multisystem minor spliceopathy defined by transcriptome-wide minor intron retention and variable short stature, immunologic, and neurodevelopmental manifestations.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Biallelic Variants in RNU6ATAC Result in a Minor Spliceopathy Characterized by Transcriptome-Wide Minor Intron Retention Events and Short Stature with Variable Multisystem Manifestations

First author:
Mendez R

Journal:
Human Genetics and Genomics Advances, Journal Pre-proof

DOI:
10.1016/j.xhgg.2026.100588

Reference:
Mendez R, Arriaga TM, Ma J, Bonner DE, Emami S, Levy RJ, Alsagheir A, Alhaddad B, Bakur K, Ungar RA, Matalon DR, Miller AM, Nguyen J, Smith KS, Scott SA, Liao L, Ng Z, Marwaha S, Ward A, Undiagnosed Diseases Network, Genomics Research to Elucidate the Genetics of Rare Diseases Consortium, Novacic D, Alkuraya FS, Bernstein JA, Ganesh VS, O’Donnell-Luria A, Montgomery SB, Wheeler MT, Biallelic Variants in RNU6ATAC Result in a Minor Spliceopathy Characterized by Transcriptome-Wide Minor Intron Retention Events and Short Stature with Variable Multisystem Manifestations, Human Genetics and Genomics Advances (2026), doi: https://doi.org/10.1016/j.xhgg.2026.100588

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/rnu6atac-minor-spliceopathy

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-03-18.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited transcript sections describing MIR as a transcriptome-wide effect, structural disruption of U4atac–U6atac, FRASER MIR filtering, need for WGS over WES, CADD/conservation evidence, tissue-specific effects, and the bridging C1 phenotype.
- transcript topics: Minor intron retention (MIR) and transcriptome-wide MIR pattern; RNU6ATAC structural disruption (Stem I/II and central stem-loop); FRASER MIR outlier analysis and tissue specificity; Whole-genome sequencing vs whole-exome sequencing; CADD scores and evolutionary conservation; Clinical bridging phenotype (A1, B1, C1) and spectrum of RNU6ATAC-opathy

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Three unrelated individuals with biallelic RNU6ATAC variants
- A1: 254 MIR outliers in whole blood; B1: 16 MIR outliers in fibroblasts
- Variants localize to U4atac–U6atac Stem I/II and central stem-loop regions
- WGS was necessary because RNU6ATAC is not targeted by standard WES kits
- RNU6ATAC variants yield CADD scores between 18 and 21
- Conservation across vertebrates, including zebrafish

QC result: Pass.

317: COPD sQTL colocalization in lung and blood identifies FBXO38 and BTC splicing mechanisms

Gustavo Barra — Mon, 16 Mar 2026 06:53:51 +0000

Saferali A et al., Human Genetics and Genomics Advances - Overlap between COPD genetic association results and transcriptional quantitative trait loci. RNA-seq in human lung (LTRC) and blood (COPDGene) reveals COPD-associated variants colocalize with splicing QTLs, implicating FBXO38 cryptic exon NMD and BTC exon4 isoform shifts. Key terms: COPD, sQTL, FBXO38, Betacellulin (BTC), long-read RNA-seq.

Study Highlights:
The study analyzed RNA-seq from COPDGene whole blood (n≈3,743) and LTRC lung tissue (n=1,241) using LeafCutter for splicing and tensorQTL for cis associations, followed by Moloc colocalization and targeted Oxford Nanopore long-read sequencing. Authors identified 58,258 lung splice sites and widespread eQTLs/sQTLs, and found 38 genomic windows (corresponding to 33 GWAS loci) with strong colocalization between QTLs and COPD GWAS signals. Top colocalizations in lung sQTLs included NPNT, FBXO38, HHIP, NTN4, and BTC, and long-read data resolved isoform changes for FBXO38 and BTC. Functionally, FBXO38 cryptic exon inclusion is associated with predicted nonsense-mediated decay and decreased expression, and BTC exon 4 inclusion alters isoform ratios that affect the EGF-like domain.

Conclusion:
Multiple COPD GWAS associations colocalize with sQTLs and eQTLs in lung and blood, identifying candidate genes such as FBXO38 and BTC and implicating splicing-mediated mechanisms in COPD risk.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Overlap between COPD genetic association results and transcriptional quantitative trait loci

First author:
Saferali A

Journal:
Human Genetics and Genomics Advances

DOI:
10.1016/j.xhgg.2025.100493

Reference:
Saferali A., Kim W., Chase R.P., NHLBI TransOmics in Precision Medicine (TOPMed), Vollmers C., Silverman E.K., Cho M.H., Castaldi P.J., Hersh C.P. Overlap between COPD genetic association results and transcriptional quantitative trait loci. Human Genetics and Genomics Advances. 2026 Jan 15;7:100493. https://doi.org/10.1016/j.xhgg.2025.100493.

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/copd-sqtl-fbxo38-btc

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-03-16.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited substantive transcript content describing COPD genetic architecture, sQTL/eQTL mapping in lung tissue (LTRC) and whole blood (COPDGene), the LeafCutter/TensorQTL/Moloc pipeline, FBXO38 cryptic exon and NMD, BTC exon 4 splicing, long-read validation, and translational implications.
- transcript topics: COPD genetic architecture and regulatory mechanisms; sQTL/eQTL mapping in lung tissue (LTRC) and whole blood (COPDGene); LeafCutter splicing analysis; TensorQTL cis associations; Moloc colocalization; FBXO38 cryptic exon and nonsense-mediated decay

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- 38 colocalization windows across 33 COPD GWAS loci with high posterior probability of shared causality (CPP>0.8)
- 58,258 lung splice sites identified in LTRC; 10,615 genes associated
- FBXO38: COPD-risk rs7730971 associated with a 158 bp cryptic exon; introduces premature stop codon and likely subjected to nonsense-mediated decay; reduced FBXO38 expression
- BTC: COPD-risk allele promotes increased inclusion of exon 4; shifts BTC isoform ratios and affects EGF-like domain
- Oxford Nanopore long-read sequencing validated FBXO38 and BTC isoforms
- Bulk RNA-seq in blood (COPDGene) and lung (LTRC) acknowledged as a limitation; single-cell follow-up suggested

QC result: Pass.

316: Inclusion bias in UCLA ATLAS: enrollment models, weighting, and effects on GWAS and PGS

Gustavo Barra — Sat, 14 Mar 2026 05:40:10 +0000

Pimplaskar A et al., The American Journal of Human Genetics - In UCLA ATLAS EHR-linked biobank analyses, random forest-derived enrollment probabilities and inverse-probability weighting increased replication of known GWAS variants and altered PGS associations. Key terms: inclusion bias, UCLA ATLAS, inverse-probability weighting, random forest, polygenic scores.

Study Highlights:
Using the UCLA ATLAS EHR-linked biobank, the authors trained random forest classifiers on demographics, healthcare utilization, and ICD-10 features to distinguish enrolled from background patients. They converted predicted enrollment probabilities into inverse-probability weights and applied these to GWAS replication tests and PGS-PheWAS scans. The classifier achieved AUROC≈0.85 and weighting increased replication of known GWAS variants by 54% while changing phenome-wide PGS association patterns. These results indicate that enrollment-driven inclusion bias can materially affect variant discovery and downstream PGS-based phenotypic associations in health-system biobanks.

Conclusion:
Inclusion bias in EHR-linked biobanks like UCLA ATLAS measurably affects common-variant discovery and PGS associations, and enrollment-aware inverse-probability weighting can improve replication while reducing effective sample size.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Inclusion bias affects common variant discovery and replication in a health-system linked biobank

First author:
Pimplaskar A

Journal:
The American Journal of Human Genetics

DOI:
10.1016/j.ajhg.2026.02.011

Reference:
Pimplaskar A, Qiu J, Lapinska S, Tozzo V, Chiang JN, Pasaniuc B, Olde Loohuis LM. Inclusion bias affects common variant discovery and replication in a health-system linked biobank. The American Journal of Human Genetics. 2026;113:1–13. https://doi.org/10.1016/j.ajhg.2026.02.011

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/inclusion-bias-ucla-atlas

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-03-14.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript sections describing enrollment-bias methodology (random forest classifier, inverse-probability weighting), key numeric results (AUROC/AUPRC, enrollment counts, ORs), GWAS replication improvements, and PGS-PheWAS outcomes, plus implications and limitations.
- transcript topics: Enrollment bias in UCLA ATLAS biobank; Random forest classifier for enrollment prediction; Inverse-probability weighting and normalization; Effective sample size and trade-offs; GWAS variant replication under weighting; Variant-level associations and ancestry effects

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Enrollment in ATLAS: background population ~1.57–1.57 million; enrolled ~104,516
- Primary care at UCLA strongly predicts enrollment: ~70.2% enrolled vs ~21.8% unenrolled; OR ≈ 8.44
- Enrolled individuals have higher healthcare utilization: ~12.8 visits/year vs ~6.7
- RF model discriminates enrollment with AUROC ≈ 0.85 and AUPRC ≈ 0.82
- Inverse-probability weighting reduces effective sample size to ≈11,319.9 (4.3× reduction; from ≈48k)
- Weighting increases replication of known GWAS variants by ≈54%

QC result: Pass.

315: PLE11-encoded Rta restricts ICP1 tail assembly in Vibrio cholerae outbreaks

Gustavo Barra — Thu, 12 Mar 2026 06:09:05 +0000

Mathur Y et al., Nature - Clinical surveillance in Bangladesh shows Vibrio cholerae acquired PLE11 encoding Rta that restricts ICP1 tail assembly, driving a selective sweep of phage-resistant strains. Key terms: Vibrio cholerae, ICP1, PLE11, Rta, phage coevolution.

Study Highlights:
This study analysed clinical Vibrio cholerae and ICP1 isolates from stool in Bangladesh using genomic surveillance, plaque assays, qPCR, experimental phage evolution, TEM and mass spectrometry. The authors identify a newly acquired mobile element, PLE11, whose small protein Rta disrupts ICP1 tail assembly by targeting the phage tape measure protein (TMP), producing genome-filled tailless capsids. PLE11 also encodes a TMP and other tail factors enabling assembly of chimeric virions that incorporate PLE-encoded TMP and BhuB, preserving satellite transmission. Continued surveillance documented natural ICP1 counteradaptation via CRISPR–Cas acquisition and convergent TMP substitutions that restore infectivity.

Conclusion:
Acquisition of PLE11 encoding the tail-targeting protein Rta drove selection of phage-resistant Vibrio cholerae in Bangladesh and prompted convergent ICP1 counteradaptations that restore phage propagation.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Capturing dynamic phage–pathogen coevolution by clinical surveillance

First author:
Mathur Y

Journal:
Nature

DOI:
10.1038/s41586-026-10136-z

Reference:
Mathur Y., Boyd C. M., Farnham J. E., Monir M. M., Islam M. T., Sultana M., Ahmed T., Alam M. & Seed K. D. Capturing dynamic phage–pathogen coevolution by clinical surveillance. Nature (2026). https://doi.org/10.1038/s41586-026-10136-z

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/ple11-rta-icp1-tail-assembly

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-03-12.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript sections that discuss the phage–bacteria arms race, PLE11 and Rta, TMP/TAC/BhuB, chimeric tail assembly, phage counterdefenses (CRISPR–Cas, Odn, Adi), and clinical surveillance data from Bangladesh, including outbreak dynamics and convergent evolution.
- transcript topics: Phage–bacteria arms race overview; Phage satellites (PLEs) and anti-PLE strategies; Rta-mediated tail assembly restriction via TMP targeting; Chimeric tail assembly with PLE11-encoded components; ICP1 counterdefenses (CRISPR–Cas, Odn, Adi) and phage evolution; Clinical surveillance in Bangladesh (BD-1.2 sweep, 2022 outbreak)

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Rta (PLE11-encoded) restricts ICP1 tail assembly by targeting TMP
- PLE11 encodes its own TMP and tail assembly factors (TAC) and BhuB to form chimeric tails enabling PLE transmission
- BD-1.2 Vibrio cholerae populations acquired PLE11 and reached ~91% prevalence within 9 months
- ICP1 populations shifted from Odn-mediated resistance to CRISPR–Cas–mediated resistance, with TMP substitutions (e.g., L362P, N355S) observed
- TEM and proteomics show PLE11 tails incorporate PLE11 TMP and BhuB and lack ICP1 TMP/BhuB, producing shorter tails (~10 nm)
- Outbreak in Dhaka, Bangladesh in early 2022 involved >42,000 cholera patients

QC result: Pass.

314: Proactive Genomic Reanalysis at Boston Children’s: VS-NN, HPO NLP and DRAGEN find diagnoses in pediatric ES/GS

Gustavo Barra — Wed, 11 Mar 2026 23:28:26 +0000

Rockowitz S et al., Human Genetics and Genomics Advances - Boston Children's Hospital used VS-NN, HPO NLP, and DRAGEN reprocessing in a proactive genomic reanalysis to identify candidate diagnoses in 2% of pediatric ES/GS cases. Key terms: genomic reanalysis, proactive reanalysis, VS-NN, HPO NLP, rare disease diagnostics.

Study Highlights:
The study deployed a centralized Proactive Genomic Reanalysis (PGR) workflow on a Boston Children’s Hospital pediatric ES/GS cohort integrated into the CRDC infrastructure. Key methods combined DRAGEN reprocessing, automated HPO extraction from EHR notes, CFA filtering on the GeneDx research platform and a VS-NN variant-scoring neural network followed by two-pass manual review. Applied to 2,144 previously unsolved cases, the pipeline flagged 310 variants, manual review prioritized 45 variants in 42 patients, and clinicians judged 33 variants to have high suspicion of disease causality, yielding ~2% candidate diagnostic rate. The work shows that institution-led, semi-automated reanalysis can produce clinically actionable findings while reducing reliance on clinician-initiated lab reanalysis, though it requires infrastructure for data transfer, confirmation and patient recontact.

Conclusion:
A centralized, semi-automated, clinically integrated Proactive Genomic Reanalysis workflow at Boston Children’s Hospital is feasible and identified candidate diagnostic variants in 2% of reviewed pediatric ES/GS cases, demonstrating a scalable model that can increase diagnoses while requiring institutional resources for confirmation and recontact.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Scaling genomic reanalysis to unlock diagnoses and transform rare disease care

First author:
Rockowitz S

Journal:
Human Genetics and Genomics Advances

DOI:
10.1016/j.xhgg.2026.100582

Reference:
Rockowitz S, Shao W, French C, Truong TK, Hagen J, McGonigle R, et al.; and Wendy K. Chung. Scaling genomic reanalysis to unlock diagnoses and transform rare disease care. Human Genetics and Genomics Advances. 2026;7:100582. https://doi.org/10.1016/j.xhgg.2026.100582.

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/proactive-genomic-reanalysis-bch

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-03-11.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the portion of the transcript describing the centralized Proactive Genomic Reanalysis (PGR) workflow, VS-NN AI scoring, NLP-based HPO extraction, CFA/DRAGEN pipelines, pilot results, and implementation challenges including data access and recontact.
- transcript topics: Centralized Proactive Genomic Reanalysis (PGR) workflow; VS-NN variant scoring neural network; HPO NLP and phenotype matching; DRAGEN read mapping and CFA filtering; Two-pass manual review process; Pilot results: dataset size, variant counts, and diagnostic yield

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- PGR pipeline yielded a 2% diagnostic rate in the initial pilot
- Pilot dataset: 2,144 patients; 62,637 variants; 310 flagged by VS-NN; 45 returnable in 42 patients; 33 high-suspicion variants
- VS-NN AUC: 0.99 for pathogenic/likely pathogenic (P/LP); 0.94 for variants of uncertain significance (VUS)
- NLP-extracted HPO terms enabled dynamic phenotyping; including NLP terms did not significantly change VS-NN scores

QC result: Pass.

313: Integrating Polygenic Risk Scores and Social Determinants of Health across Populations

Gustavo Barra — Tue, 10 Mar 2026 06:07:46 +0000

Cromer SJ et al., The American Journal of Human Genetics - This paper reviews polygenic risk scores (PRS) and social determinants of health (SDoH) and outlines best practices for integrating PRS and SDoH across diverse populations to improve prediction and equity. Key terms: polygenic risk scores, social determinants of health, PRS transferability, data harmonization, type 2 diabetes.

Study Highlights:
This review focuses on human populations and uses conceptual frameworks, hypothetical population examples, and synthesis of methodological studies to evaluate PRS and SDoH integration. It summarizes methods for PRS construction and transferability, SDoH measurement at individual and area levels, and analytic approaches including interaction, mediation, and calibration. Quantitatively, the authors note substantial declines in PRS predictive accuracy when applied to genetically distinct populations (for example, African-ancestry performance often ~20–40% of European-derived PRS). The review highlights harmonization, population-specific calibration, and interdisciplinary teams as functional steps to improve predictive validity and reduce inequitable impacts.

Conclusion:
Integrating PRSs with carefully measured and harmonized SDoH across diverse populations requires population-aware conceptual frameworks, calibrated analytic methods, diverse datasets, and ethical safeguards to improve predictive validity and equity.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Incorporating polygenic risk scores and social determinants of health across populations: Considerations and best practices in research

First author:
Cromer SJ

Journal:
The American Journal of Human Genetics

DOI:
10.1016/j.ajhg.2026.02.007

Reference:
Cromer SJ, Cobran EK, Iyer HS, Hysong MR, Vargas LB, Smith JL, Konigsberg IR, Bogumil D, Glover L, King G, PRIMED Consortium SDoH Working Group, Lange LA, Patel A, Wojcik G, Raffield L, Conti DV, et al. Incorporating polygenic risk scores and social determinants of health across populations: Considerations and best practices in research. The American Journal of Human Genetics. 2026;113:1–25. https://doi.org/10.1016/j.ajhg.2026.02.007

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/polygenic-risk-sdoh-harmonization

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-03-10.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited substantive sections of the transcript covering PRS basics, PRS transferability across populations, SDoH domains and measurement, harmonization challenges, analytical frameworks (main effects, interactions, mediation), T2D as an illustrative case, and ethical considerations.
- transcript topics: PRS basics and transferability; SDoH four-domain framework (socioeconomic, sociocultural, physical environment, healthcare access); Individual vs area-level SDoH measures; SDoH harmonization across datasets; Analytical frameworks (main effects, interaction/effect modification, mediation); T2D as illustrative example

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- PRS predictive accuracy declines across populations; African-ancestry accuracy ~20–40% of European-derived PRS
- SDoH clustering, distribution, and effect sizes vary across populations and can modify PRS effects; harmonization improves transferability
- Ethical and representation issues are critical to study design and interpretation
- Race and ethnicity are socially constructed; genetic similarity is a continuous spectrum
- SDoH measured at individual and area levels across four domains
- Harmonization of SDoH measures is challenging; ecological fallacy cautions apply

QC result: Pass.

312: Mfsd2a transports LPC to maintain epidermal linoleate pools and desquamation

Gustavo Barra — Mon, 09 Mar 2026 23:50:06 +0000

Wong BHH et al., Proc. Natl. Acad. Sci. U.S.A - Mouse and human studies show the LPC transporter Mfsd2a enables plasma-derived LPC uptake into keratinocytes, preserving linoleate-rich phosphatidylcholine pools and promoting epidermal differentiation. Key terms: Mfsd2a, lysophosphatidylcholine, keratinocyte differentiation, linoleic acid, lipidomics.

Study Highlights:
Using epidermis-specific (2aEpKO) and conventional (2aKO) Mfsd2a-deficient mice, lineage tracing, untargeted shotgun lipidomics, LightOx-LPC uptake assays, and primary human keratinocyte cultures, the authors mapped Mfsd2a expression to suprabasal/granular keratinocytes and demonstrated Mfsd2a-dependent uptake of plasma-derived LPC in vivo. Lipidomic quantification showed reductions in linoleate-containing phospholipids (PL-18:2 decreased ~15% in 2aEpKO and ~13% in 2aKO) and a marked loss of TAG-18:2 (−79% in 2aEpKO). Inducible epidermal Mfsd2a loss produced transient dermatitis, defective desquamation, retained lamellar bodies, and keratinocyte activation, while MFSD2A knockdown in human keratinocytes reduced LPC-driven differentiation. Functional rescue experiments in vitro revealed that LPC-18:1 and LPC-18:2 promote keratinocyte differentiation in an MFSD2A-dependent manner, linking plasma LPC uptake to epidermal lipid homeostasis and differentiation.

Conclusion:
Mfsd2a mediates uptake of plasma-derived LPC (notably LPC-18:2) into suprabasal keratinocytes to maintain linoleate-containing phospholipid pools and support keratinocyte differentiation and normal desquamation.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Mfsd2a is important for maintaining epidermal homeostasis

First author:
Wong BHH

Journal:
Proc. Natl. Acad. Sci. U.S.A

DOI:
10.1073/pnas.2531159123

Reference:
Wong BHH, Behmoaras J, Chua AWC, Galam DLA, Tan BC, Torta F, Chin CF, Mishra K, Ding M, Silver DL. Mfsd2a is important for maintaining epidermal homeostasis. Proc. Natl. Acad. Sci. U.S.A. 2026 Feb 19;123(8):e2531159123. https://doi.org/10.1073/pnas.2531159123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/mfsd2a-lpc-epidermal-homeostasis

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-03-09.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript sections describing MFSD2A expression in epidermal keratinocytes, inducible epidermis-specific and conventional Mfsd2a knockout phenotypes, epidermal lipidomics (18:2 species and DAG shifts), LightOx-LPC uptake demonstrating MFSD2A dependence, and MFSD2A-dependent differentiation of human keratin
- transcript topics: MFSD2A expression in differentiated epidermal keratinocytes; Inducible postnatal Mfsd2a deficiency and dermatitis; Conventional Mfsd2a knockout and desquamation defects; Epidermal lipidomics: PL-18:2 and TAG-18:2 reductions; DAG shifts; LPC uptake into epidermis using LightOx-LPC and MFSD2A dependence; MFSD2A-dependent differentiation of human keratinocytes with LPCs

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- MFSD2A is predominantly expressed in differentiated epidermal keratinocytes, enriched in the granular layer
- Inducible epidermis-specific Mfsd2a deficiency (2aEpKO) causes dermatitis, defective desquamation, hyperkeratosis, and keratinocyte activation
- Conventional Mfsd2a knockout (2aKO) shows desquamation defects with hyperkeratosis and parakeratosis
- Epidermal lipidome is altered by Mfsd2a deficiency, with reduced PL-18:2 and TAG-18:2 and reciprocal DAG changes
- Plasma-derived LPC uptake into epidermis is MFSD2A-dependent, demonstrated by LightOx-LPC uptake being absent in 2aEpKO/2aKO but present in controls
- LPC18:1 and LPC18:2 promote human primary keratinocyte differentiation in an MFSD2A-dependent manner

QC result: Pass.

311: mtG3PDH (GPO1) loss in Drosophila impairs mitochondrial ATP/O, O2 consumption, and ROS

Gustavo Barra — Sun, 08 Mar 2026 07:18:38 +0000

Herpe L et al., Proc. Natl. Acad. Sci. U.S.A - CRISPR knockout of Drosophila mtG3PDH (GPO1) reduces ATP production by ~60% and O2 consumption by ~33%, lowering mitochondrial efficiency and ROS emission. Key terms: mtG3PDH, GPO1, Drosophila melanogaster, mitochondrial efficiency, reactive oxygen species.

Study Highlights:
Using CRISPR/Cas9-generated GPO1 mutant Drosophila and isolated thoracic mitochondria, the authors combined enzymatic assays, ATP production and oxygen consumption measurements, and H2O2 emission assays to probe mtG3PDH function. Loss of mtG3PDH markedly reduced mtG3PDH enzymatic activity and drove a ~60% decrease in ATP production and ~33% decrease in O2 consumption, producing a pronounced drop in mitochondrial efficiency (ATP/O). mtG3PDH-linked ROS emission was also strongly reduced (~70%), reflecting diminished direct and reverse electron-transfer ROS generation. Functionally, GPO1 flies showed sharply reduced survival and severe climbing impairment, linking the bioenergetic defects to organismal outcomes.

Conclusion:
mtG3PDH is essential for mitochondrial bioenergetics and redox homeostasis in Drosophila, with GPO1 loss causing major decreases in ATP production, O2 consumption, mitochondrial efficiency, and mtG3PDH-linked ROS that correlate with reduced survival and locomotion.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
When alternative becomes essential: The role of mitochondrial glycerol-3-phosphate dehydrogenase

First author:
Herpe L

Journal:
Proc. Natl. Acad. Sci. U.S.A

DOI:
10.1073/pnas.2535701123

Reference:
Herpe L, Aminot M, Pichaud N. When alternative becomes essential: The role of mitochondrial glycerol-3-phosphate dehydrogenase. Proc. Natl. Acad. Sci. U.S.A. 2026;123(9):e2535701123. https://doi.org/10.1073/pnas.2535701123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/drosophila-mtg3pdh-gpo1

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-03-08.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited sections cover mtG3PDH function, CRISPR/Cas9 GPO1 knockout in Drosophila, thoracic mitochondria bioenergetics (ATP production, oxygen consumption, ATP/O), ROS production and RET, organismal outcomes (lifespan, climbing), and translational implications.
- transcript topics: mtG3PDH shuttle function and GPO1; CRISPR/Cas9 GPO1 knockout in Drosophila; thoracic mitochondria bioenergetics: ATP production; oxygen consumption and coupling efficiency (ATP/O); ROS production and reverse electron transfer; complex I independence and grid collapse

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 5
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- mtG3PDH knockout reduces ATP production by ~60%
- O2 consumption decreases by ~33%
- mitochondrial efficiency (ATP/O) is markedly reduced (uncoupling observed)
- mtG3PDH-linked ROS emission decreases by ~70%
- survival (median lifespan) drops from ~33 days to ~12 days in GPO1 mutants
- climbing performance declines to ~1% in mutants (vs ~68.5% in controls)

QC result: Pass.

310: Infant gut microbiota restoration — maternal FMT, Bifidobacterium and Bacteroides recovery after C‑section

Gustavo Barra — Sat, 07 Mar 2026 11:27:27 +0000

Korpela K et al., Gut Microbes - Review finds maternal fecal microbiota transplantation and targeted probiotics can restore Bifidobacterium and Bacteroides after C‑section or intrapartum antibiotics, with breastfeeding aiding recovery. Key terms: maternal fecal microbiota transplantation, C-section, Bifidobacterium, vaginal seeding, probiotics.

Study Highlights:
This review focuses on term infants, particularly C‑section and intrapartum antibiotic–exposed neonates, synthesizing cohort and intervention data using 16S rRNA gene amplicon sequencing and metagenomic approaches. Maternal fecal microbiota transplantation (maternal FMT) shifted C‑section infants’ gut communities to resemble vaginally born infants and uniquely restored Bacteroidaceae, while a Bifidobacterium–Lactobacillus–FOS supplement increased bifidobacteria; vaginal seeding did not normalize overall gut composition. The authors link restoration of key taxa to potential reductions in risks such as allergy and overweight and emphasize breastfeeding as an essential adjunct to restoration strategies.

Conclusion:
Evidence supports action to address early-life gut microbiota disruption: probiotics and maternal FMT show promising restorative effects, but optimal, scalable solutions and long-term immune outcomes remain to be established.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Infant gut microbiota restoration: state of the art

First author:
Korpela K

Journal:
Gut Microbes

DOI:
10.1080/19490976.2022.2118811

Reference:
Korpela K, de Vos WM. Infant gut microbiota restoration: state of the art. Gut Microbes. 2022;14(1):e2118811. https://doi.org/10.1080/19490976.2022.2118811

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/maternal-fmt-bifidobacterium-restoration

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-03-07.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript sections describing vertical transmission, HMOs and breast milk, birth-mode and antibiotic effects, restoration interventions (vaginal seeding, Lactobacillus probiotics, Bifidobacterium-Lactobacillus-FOS multispecies, maternal FMT), PCA-based analysis, preterm considerations, and long-term health
- transcript topics: Vertical transmission and HMOs feeding infant gut microbes; Birth mode and intrapartum antibiotic effects on microbiota; Microbiota restoration interventions: vaginal seeding, probiotics, multispecies probiotics, maternal FMT; PCA analysis as a measure of restoration efficacy; Bifidobacteriaceae and Bacteroidaceae dynamics across interventions; Preterm infant microbiota and NICU interventions

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Maternal FMT can restore CS-born infant gut microbiota toward vaginal births, with persistence at 1 and 3 months
- Bacteroidaceae restoration is achieved by maternal FMT; other interventions fail to restore this family
- Vaginal seeding does not restore gut microbiota composition (fails to move CS-born infants toward vaginal baseline)
- Lactobacillus-only probiotic shows minimal to no restoration of the gut microbiota in CS-born infants
- Multispecies Lactobacillus–Bifidobacterium–FOS probiotic partially restores gut microbiota toward vaginal composition; benefits observed in larger RCT with reduced IgE-allergy risk
- Breastfeeding enhances probiotic/restoration effects; HMOs fuel infant-adapted microbes and are essential for full restoration

QC result: Pass.

309: LASI-DAD 2,680-sample WGS panel boosts LD maps, imputation, and PRS in Indian genomes

Gustavo Barra — Fri, 06 Mar 2026 06:17:45 +0000

Li Z et al., Human Genetics and Genomics Advances - LASI-DAD 30× whole-genome sequencing of 2,680 Indian participants produced a 69.5M-variant LD panel that improves genotype imputation accuracy and PRS performance for Indian populations. Key terms: LASI-DAD, linkage disequilibrium, genotype imputation, whole-genome sequencing, polygenic risk scores.

Study Highlights:
Using 30× WGS of 2,680 LASI-DAD participants, the authors constructed an LD lookup panel (69.5 million variants), phased with Eagle2.4, and identified LD structure with LDetect and Big-LD. They compared regional varLD to 1000G super-populations and evaluated imputation with Minimac4 and meta-imputation against TOPMed and GAsP. LASI-DAD increased imputation accuracy (aggregated r2) by a mean 38% versus TOPMed and 27% versus GAsP across allele frequencies and improved PRS predictive performance by 2.1%–35.1% across traits and studies. Finer-scale stronger LD and regional LD differences in LASI-DAD translate into more accurate LD estimates and better imputation and PRS transferability for Indian sub-populations.

Conclusion:
LASI-DAD is the largest nationally representative Indian WGS reference panel to date and it improves LD estimation, genotype imputation accuracy, and PRS construction for Indian and South Asian populations.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
A reference panel for linkage disequilibrium and genotype imputation using whole-genome sequencing data from 2,680 participants across India

First author:
Li Z

Journal:
Human Genetics and Genomics Advances

DOI:
10.1016/j.xhgg.2026.100579

Reference:
Li Z, Zhao W, Zhou X, Leung YY, Schellenberg GD, Wang L-S, Schönherr S, Forer L, Fuchsberger C, Dey S, Lee J, Smith JA, Dey AB, Kardia SLR. A reference panel for linkage disequilibrium and genotype imputation using whole-genome sequencing data from 2,680 participants across India. Human Genetics and Genomics Advances. 7 (2026) 100579. https://doi.org/10.1016/j.xhgg.2026.100579.

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/lasi-dad-india-reference-panel

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-03-06.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Substantive auditing of the transcript’s scientific content covered the LASI-DAD cohort design and sequencing depth; LD/imputation methodology (LD blocks, LDetect/Big-LD, varLD); LD panel variant counts; subpopulation structure (ANI/ASI) and PRS transferability; imputation performance and meta-imputation; and data avai
- transcript topics: LASI-DAD cohort design and 30× whole-genome sequencing; LD reference panel construction and variant counts (69.5 million) and comparisons; LD blocks and varLD analyses across populations; LASI-DAD sub-populations by ANI percentage and geographic cline; PRS transferability and cross-population performance; Imputation performance and meta-imputation across reference panels

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- LASI-DAD WGS sample size = 2,680 individuals
- Sequencing depth = 30×
- LD reference panel variant count = 69.5 million
- Imputation gains: mean aggregated r2 improvements = 38% versus TOPMed and 27% versus Genome Asia Pilot (GAsP)
- PRS predictive performance improvement = 2.1%–35.1% across traits and studies
- Rare variant imputation: 61,843,011 variants imputed

QC result: Pass.

308: PANDORA-seq reveals conserved rsRNA length shift and tsRNA/rsRNA aging cliff in mouse and human sperm

Gustavo Barra — Thu, 05 Mar 2026 05:52:10 +0000

Shi J et al., The EMBO Journal, doi:10.1038/s44318-025-00687-8 - PANDORA-seq profiling of mouse and human sperm heads identifies a conserved rsRNA length shift with age and a tsRNA/rsRNA 'aging cliff' that reprograms embryonic transcripts. Key terms: sperm sncRNA, rsRNA length shift, PANDORA-seq, aging cliff, tRNA-derived small RNA.

Study Highlights:
Using PANDORA-seq on C57BL/6J mouse sperm (intact and de-membranated heads) across five age groups and two independent human sperm cohorts, the authors identify a sharp tsRNA/rsRNA "aging cliff" in mice between 50–70 weeks and a head-specific rsRNA length shift. PANDORA-seq overcomes modification-induced detection bias to reveal increases in longer rsRNAs and decreases in shorter rsRNAs, particularly from 28S- and 18S-rRNAs, with parallel trends in human cohorts. Mitochondrial tsRNAs/rsRNAs in sperm heads, although low abundance, covary with genomic sncRNAs and help distinguish age groups. Transfection of age-mimicking tsRNA/rsRNA cocktails into mouse embryonic stem cells reprograms gene expression, upregulating metabolic and neurodegeneration-related pathways, providing a functional link to offspring phenotypes.

Conclusion:
PANDORA-seq uncovers a conserved, sperm head–specific rsRNA length shift and a tsRNA/rsRNA aging cliff in mice and humans, and age-mimicking sncRNA combinations can alter embryonic transcriptomes linked to metabolic and neurodegenerative pathways.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Conserved shifts in sperm small non-coding RNA profiles during mouse and human aging

First author:
Shi J

Journal:
The EMBO Journal, doi:10.1038/s44318-025-00687-8

DOI:
10.1038/s44318-025-00687-8

Reference:
Shi J, Zhang X, Cai C, Liu S, Yu J, James ER, et al. Conserved shifts in sperm small non-coding RNA profiles during mouse and human aging. The EMBO Journal. 2026;45(4):1362–1380. https://doi.org/10.1038/s44318-025-00687-8

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/sperm-rsrna-length-shift

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-03-05.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Substantively audited the transcript segments describing (1) the aging cliff in mouse sperm tsRNA/rsRNA profiles, (2) rsRNA length shifts in sperm heads, (3) cross-species conservation in humans, (4) mitochondrial sncRNA patterns, (5) functional RNA transfection experiments in mouse embryonic stem cells, (6) the PANDOR
- transcript topics: PANDORA-seq methodology; mouse sperm aging cliff at 50-70 weeks; rsRNA length shift in mouse sperm heads (28S/18S origin); mitochondrial tsRNA/rsRNA patterns in sperm heads; conservation of rsRNA length shift in human sperm cohorts; functional reprogramming of mESC transcriptomes by age-mimicking sncRNA cocktails

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Aging cliff between 50 and 70 weeks in mouse sperm sncRNA profiles detected by PANDORA-seq.
- Sperm-head rsRNAs show an age-related length shift: longer rsRNAs increase and shorter rsRNAs decrease, especially from 28S- and 18S-derived rsRNAs.
- Conserved rsRNA length shift observed in humans across two independent cohorts (longitudinal and cross-sectional).
- Mitochondrial rsRNAs/tsRNAs detected in de-membranated sperm heads co-vary with genomic sncRNA aging patterns.
- Age-mimicking tsRNA/rsRNA cocktails transfected into mouse embryonic stem cells reprogram transcriptomes toward metabolic and neurodegeneration pathways.
- Pandora-seq overcomes RNA modification-induced detection bias to reveal previously undetectable sncRNA species.

QC result: Pass.

307: SNIPE membrane nuclease cleaves phage λ DNA during ManYZ-mediated genome injection in Escherichia coli

Gustavo Barra — Wed, 04 Mar 2026 05:31:22 +0000

Saxton DS et al., Nature, doi:10.1038/s41586-026-10207-1 - In E. coli, the membrane-bound nuclease SNIPE directly cleaves incoming phage λ DNA during genome injection, blocking infection via ManYZ and tape-measure protein interactions. Key terms: SNIPE, GIY-YIG nuclease, lambda phage, ManYZ, tape measure protein.

Study Highlights:
In Escherichia coli, the membrane-anchored protein SNIPE was shown to block phage λ by directly cleaving DNA during genome injection. The authors combined radiolabelled 32P phage DNA assays, time-lapse CFP-ParB/ParS microscopy, TurboID proximity labelling and pBPA crosslinking to map SNIPE localization and interactions. They report that membrane-localized SNIPE requires a DUF4041 domain and a GIY-YIG nuclease domain to generate DNA fragments during injection, reducing CFP-ParB puncta ~30-fold and producing a smear of 32P-labelled fragments; an E414A nuclease mutant abolished activity. Functionally, SNIPE prevents λ replication and cell lysis and provides broad defence against many siphoviruses via interactions with ManYZ and phage tape-measure proteins.

Conclusion:
SNIPE is a membrane-localized bacterial defence protein that associates with ManYZ and phage tape-measure proteins to directly cleave incoming phage DNA during genome injection, thereby blocking infection.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
A membrane-bound nuclease directly cleaves phage DNA during genome injection

First author:
Saxton DS

Journal:
Nature, doi:10.1038/s41586-026-10207-1

DOI:
10.1038/s41586-026-10207-1

Reference:
Saxton DS, DeWeirdt PC, Doering CR, Roney IJ & Laub MT. A membrane-bound nuclease directly cleaves phage DNA during genome injection. Nature. 2026. https://doi.org/10.1038/s41586-026-10207-1

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/snipe-membrane-nuclease-phage-injection

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-03-04.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited transcript sections covering SNIPE architecture and membrane localization, autoinhibition, phage DNA cleavage during genome injection (Hershey–Chase style), interactions with ManYZ andTape-measure proteins (TMP), proximity labelling, Bas14 mutation experiments, and SNIPE homologues/evolution.
- transcript topics: SNIPE membrane localization and domain architecture; Autoinhibition and self-DNA protection at the membrane; Cleavage of phage DNA during genome injection and Hershey–Chase-like evidence; Interaction with ManYZ and phage tape-measure protein during infection; TurboID proximity labelling findings for ManYZ and TMP interactions; Broad siphovirus defense and Bas14 mutation findings

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- SNIPE is a membrane-anchored protein with an N-terminal transmembrane domain, a DUF4041 domain in the middle, and a GIY-YIG nuclease domain at the C-terminus.
- SNIPE autoinhibits its nuclease activity when anchored to the inner membrane to avoid autoimmune DNA cleavage.
- SNIPE cleaves phage DNA during genome injection, producing fragmented 32P DNA signals and reducing infection.
- CFP-ParB foci (parS-labelled phage DNA) are reduced by ~30-fold in SNIPE-expressing cells during λparS infection.
- A Hershey–Chase–style assay shows a smear of 32P-labelled DNA fragments in SNIPE-expressing cells, reversed by nuclease-inactive mutants (E414A).
- SNIPE associates with ManYZ before infection and with phage tape-measure proteins during genome injection.

QC result: Pass.

306: SAXO6 loss-of-function in photoreceptor cilia links a microtubule inner protein to late-onset retinal dystrophy

Gustavo Barra — Tue, 03 Mar 2026 06:02:31 +0000

Moye AR et al., The American Journal of Human Genetics - Biallelic loss-of-function variants in SAXO6, a microtubule inner protein of photoreceptor cilia, cause late-onset retinal dystrophy by destabilizing axonemal microtubules. Key terms: SAXO6, microtubule inner protein, photoreceptor cilia, retinal dystrophy, iU-ExM.

Study Highlights:
The study analyzed human patients with late-onset recessive retinal dystrophy and combined genetic sequencing (WES/WGS and long-read RNA) with high-resolution imaging and proteomics. Iterative ultrastructure expansion microscopy and immuno-gold TEM localized SAXO6 to specific microtubule doublets in photoreceptor connecting cilia and outer segments and to motile cilia in airway models. Cross-linking mass spectrometry on isolated bovine tracheal cilia detected an interaction between SAXO6 Mn-motif regions and α-tubulin (Lys370), supporting SAXO6 as a microtubule inner protein. Functionally, predicted null SAXO6 genotypes segregate with late-onset RP or cone-rod dystrophy, implicating MIP dysfunction in long-term photoreceptor stability.

Conclusion:
Biallelic loss-of-function variants in SAXO6 cause late-onset retinal dystrophy, likely by disrupting a microtubule inner protein that stabilizes photoreceptor axonemes.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Loss-of-function variants in SAXO6, encoding a microtubule inner protein of photoreceptor cilia, cause a late-onset retinal dystrophy

First author:
Moye AR

Journal:
The American Journal of Human Genetics

DOI:
10.1016/j.ajhg.2026.02.001

Reference:
Moye AR, McCafferty CL, Lin S, Han JH, Dudakova L, Rodenburg K, Szabó V, Nagy ZZ, Zur D, Vajter M, Kousal B, Moulin AP, Graff-Meyer A, Roosing S, Mahroo OA, Arno G, Webster AR, Ben-Yosef T, Liskova P, Engel BD, Zobor D, Quinodoz M, Rivolta C. Loss-of-function variants in SAXO6, encoding a microtubule inner protein of photoreceptor cilia, cause a late-onset retinal dystrophy. The American Journal of Human Genetics. 2026 Mar 5;113:1–18. https://doi.org/10.1016/j.ajhg.2026.02.001

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/saxo6-photoreceptor-mip-retina

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-03-03.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited transcript sections covering SAXO6 gene discovery and renaming from MDM1; SAXO6 LOF variants and segregation; SAXO6 localization in photoreceptor cilia and motile cilia; imaging methods iU-ExM and Ig-TEM; cross-linking MS evidence for SAXO6–α-tubulin interaction; rod vs cone MT doublet occupancy; clinical impli
- transcript topics: SAXO6 gene discovery and renaming from MDM1; Bi-allelic SAXO6 LOF variants and family segregation; Subcellular localization of SAXO6 in photoreceptor cilia (CC/OS) and in motile cilia; Imaging methods: iterative ultrastructure expansion microscopy (iU-ExM); Immuno-gold TEM localization of SAXO6; Cross-linking mass spectrometry evidence for SAXO6–α-tubulin interaction

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Six individuals from five families carry bi-allelic SAXO6 loss-of-function variants associated with late-onset RP/CRD
- SAXO6 renamed from MDM1 to SAXO6 (stabilizer of axonemal microtubules 6)
- SAXO6 localizes inside the lumen of photoreceptor ciliary microtubules and in motile cilia
- Cross-linking MS identifies an interaction between SAXO6 (Lys201) and α-tubulin (Lys370) with ~30 Å separation
- Iterative ultrastructure expansion microscopy expanded tissue ~10×, revealing SAXO6 localization along microtubule doublets
- Rods show SAXO6 occupancy on 6–7 microtubule doublets; cones on all 9 doublets

QC result: Pass.

305: Human cis-regulatory variants dissected by MPRA at single-nucleotide resolution

Gustavo Barra — Mon, 02 Mar 2026 06:31:33 +0000

Siraj L et al., Nature, doi:10.1038/s41586-026-10121-6 - Using MPRA in five human cell types, the authors assayed 221,412 fine-mapped variants and identified 13,121 trait-associated regulatory variants (TARVs), mapping mechanisms at single-nucleotide resolution. Key terms: massively parallel reporter assay, trait-associated regulatory variants, saturation mutagenesis, transcription factor motifs, regulatory epistasis.

Study Highlights:
The study assayed 221,412 fine-mapped human GWAS and eQTL variants using a massively parallel reporter assay (MPRA) across five cell lines and performed saturation mutagenesis on 136 TARVs. MPRA identified 13,121 trait-associated regulatory variants (TARVs) and showed that emVar status within endogenous CREs improves precision for causal-variant prioritization. Saturation mutagenesis defined activity blocks, assigned transcription factors for 91% of previously non-canonical TARVs, and revealed that only 69% of TARVs disrupt known TF motifs. The authors also detected regulatory epistasis in ~11% of nearby variant pairs, demonstrating non-additive effects between cis variants.

Conclusion:
Large-scale MPRA combined with saturation mutagenesis systematically identifies and mechanistically annotates thousands of human trait-associated regulatory variants at single-nucleotide resolution, revealing motif-disrupting and non-canonical TF mechanisms and local epistasis.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Functional dissection of complex trait variants at single-nucleotide resolution

First author:
Siraj L

Journal:
Nature, doi:10.1038/s41586-026-10121-6

DOI:
10.1038/s41586-026-10121-6

Reference:
Siraj L., Castro R.I., Dewey H.B., Kales S., Butts J.C., Nguyen T.T.L., Kanai M., et al. Functional dissection of complex trait variants at single-nucleotide resolution. Nature. https://doi.org/10.1038/s41586-026-10121-6

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/mpra-human-regulatory-variants

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-03-02.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript’s coverage of MPRA scale and variant coverage, TARV identification and counts, mechanistic categories (motif disruption and non-canonical mechanisms), saturation mutagenesis mapping, regulatory epistasis, recall/precision metrics, cell-type context, and translational HbA1c example.
- transcript topics: MPRA scale and variant coverage; TARV identification and counts; Motif disruption as mechanism; Saturation mutagenesis mapping and activity blocks; Non-canonical TARV mechanisms; Regulatory epistasis in nearby TARV pairs

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- MPRA tested 221,412 fine-mapped trait-associated variants
- Identified 13,121 TARVs with high precision
- 69% of TARVs disrupt known transcription factor motifs
- Saturation mutagenesis assigned TFs for 91% of non-canonical TARVs
- Regulatory epistasis detected in ~11% of nearby TARV pairs
- Precision for causal-variant prioritization ~82–83%; recall ~15–20%

QC result: Pass.

304: Patrilineal Y‑chromosome drive in a Utah pedigree (67% male offspring)

Gustavo Barra — Mon, 02 Mar 2026 05:28:16 +0000

Baldwin-Brown JG et al., Annual Review of Ecology and Systematics - Bayesian analysis of 76,445 Utah Population Database pedigrees identifies a patrilineal Y‑chromosome lineage producing a 2:1 male bias, consistent with segregation distortion. Key terms: segregation distortion, Y chromosome, sex ratio, Utah Population Database, Bayesian pedigree analysis.

Episode title:
Patrilineal Y‑chromosome drive in a Utah pedigree (67% male offspring)

Study Highlights:
We analyzed 76,445 anonymized human pedigrees from the Utah Population Database using a Bayesian pedigree-propagation algorithm (Warp), complemented by transmission disequilibrium testing, permutation and Monte Carlo simulations. These methods identified a single patrilineal Y-chromosome lineage with 89 informative transmissions that produced 60 male and 29 female offspring, a 67.4% male proportion. Warp and the TDT independently flagged the same family and permutation/Monte Carlo tests indicated the observed male bias was unlikely to arise by chance (p≈0.001–0.05). The pattern is consistent with a Y-linked segregation distorter and is discussed as a possible contributor to unexplained male infertility and human sex-ratio dynamics.

Conclusion:
A multi-method analysis of deep Utah pedigrees identifies a statistically significant male-biased patrilineal lineage consistent with a Y-linked segregation distorter in humans.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Signatures of sex ratio distortion in humans

First author:
Baldwin-Brown JG

Journal:
Annual Review of Ecology and Systematics

DOI:
10.64898/2026.02.04.702084

Reference:
Baldwin-Brown JG, Wesolowski S, Zimmerman RM, Peterson B, Tristani-Firouzi M, Hernandez EH, Aston KI, Yandell M, Phadnis N. Signatures of sex ratio distortion in humans. Annual Review of Ecology and Systematics. 2026. https://doi.org/10.64898/2026.02.04.702084

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/human-y-chromosome-drive

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-03-02.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited transcript segments describing segregation distortion concepts, Warp Bayesian algorithm for detecting distorters, the UPDB/focal patrilineal lineage with 67.4% male offspring across 89 transmissions, TDT results, Monte Carlo validation, proposed Y-chromosome mechanisms (PRY cluster), and implications (male infe
- transcript topics: Segregation distortion concepts and Mendelian expectations; Warp Bayesian algorithm for detecting distorters in UPDB pedigrees; UPDB data and identification of a patrilineal Y-chromosome lineage with 60/29 across 89 transmissions; Transmission Disequilibrium Test (TDT) results; Monte Carlo validation of lineage bias (p ≈ 0.00138); Potential molecular mechanisms: PRY ampliconic gene cluster

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Identification of a patrilineal Y-chromosome distorter signal in humans using UPDB data (67.4% male across 89 transmissions in focal lineage)
- Warp Bayesian algorithm applied to UPDB pedigrees identifies putative distorter-carrying lineages (two male-biased families detected; six female-biased families)
- Focal patrilineal lineage across 89 informative transmissions yields 60 male and 29 female offspring (67.4% male)
- Transmission Disequilibrium Test (TDT) identifies the focal patrilineal lineage as significantly male biased (p ≈ 0.0249 after FDR; uncorrected p ≈ 0.00102)
- Monte Carlo simulations yield p ≈ 0.00138 for the focal lineage
- PRY gene cluster on the Y chromosome discussed as a prime mechanistic candidate for distortion

QC result: Pass.

303: Short-read sequencing and genome skimming for biodiversity monitoring and phylogenomics

Gustavo Barra — Sat, 28 Feb 2026 20:18:01 +0000

Bleidorn C et al., Trends in Genetics, 42 (2026) 137-149. doi:10.1016/j.tig.2025.09.001 - This review shows how short-read shotgun sequencing and genome skimming recover organellar genomes, estimate genome size and repeat content, and enable scalable biodiversity monitoring. Key terms: short-read sequencing, genome skimming, metagenomics, museum genomics, phylogenomics.

Study Highlights:
The authors review applications across eukaryotic biodiversity, museum specimens, bulk samples and eDNA using short-read shotgun sequencing and genome skimming. They detail assembly-free and mapping-based bioinformatic methods (k-mer analyses, Read2Tree, Kraken2/CONSULT) and target-enrichment approaches for recovering phylogenetic markers. Quantitatively, low-coverage skims (from <1× to ~20×) can reliably recover organellar genomes and estimate genome size and repeat content using tools such as RESPECT and GenomeScope. Functionally, these approaches enable rapid reference database building, biomass estimation, and scalable monitoring that support the Global Biodiversity Framework.

Conclusion:
Short-read sequencing remains a cost-effective, broadly applicable toolkit that complements long-read references by enabling genome skimming, genome-size and repeat estimation, phylogenetics from low-coverage data, and museum-based biodiversity sampling.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
The untapped potential of short-read sequencing in biodiversity research

First author:
Bleidorn C

Journal:
Trends in Genetics, 42 (2026) 137-149. doi:10.1016/j.tig.2025.09.001

DOI:
10.1016/j.tig.2025.09.001

Reference:
Bleidorn C, Podsiadlowski L, Sandberg F, Martin S, Vogler AP. The untapped potential of short-read sequencing in biodiversity research. Trends Genet. 2026;42:137-149. https://doi.org/10.1016/j.tig.2025.09.001

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/short-read-genome-skimming

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-02-28.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript’s scientific content: GBF motivation, short-read sequencing and genome skimming, museomics (Barcode Blitz), type genomics, assembly-free phylogenomics (USCOs, UCEs, k-mers), environmental DNA/metagenomics and biomass estimation, hologenome/holobiont concept, and sequencing economics.
- transcript topics: GBF motivation and large-scale biodiversity monitoring; Short-read sequencing basics and genome skimming; Museomics and Barcode Blitz (museum collections, degraded DNA); Type genomics and reference database curation; Assembly-free phylogenomics (USCOs, UCEs, k-mers); Environmental DNA/metagenomics and biomass estimation

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Short-read sequencing provides a universal data source across scales from genomes to ecosystems and supports GBF objectives.
- Genome skimming yields high-copy DNA (organellar genomes, ribosomal repeats) from low-coverage data (5×–20×; ultralow <5× sometimes).
- Museum collections enable large-scale genomic data generation (e.g., Barcode Blitz) from degraded DNA.
- Type genomics creates validated reference datasets by sequencing type material.
- USCOs and assembly-free methods (e.g., Skmer, Mash, Read2Tree) enable phylogenomics from unassembled reads.
- PCR/metabarcoding biases are bypassed by genome skimming/metagenomics, improving biomass estimates.

QC result: Pass.

302 auf Deutsch: SMN1/SMN2-Spleißen und Mechanismen im letzten Exon — Hommage an Brunhilde Wirth

Gustavo Barra — Fri, 27 Feb 2026 11:07:54 +0000

Ein Hommage-Dossier, das die wissenschaftliche Laufbahn von Prof. Brunhilde Wirth würdigt und Arbeiten zum alternativen Spleißen von SMN1/SMN2 hervorhebt. Im Fokus stehen Studien aus der molekularen Genetik und funktionelle Assays, die die Auswirkungen von Varianten bei SMA aufgeklärt haben.

Studien-Highlights:

Dieses Dossier beleuchtet jahrzehntelange Arbeit in der Humangenetik und zur spinalen Muskelatrophie und betont insbesondere Studien zu SMN1 und SMN2. Zu den zentralen Methoden gehörten molekulargenetische Analysen, Spleißanalysen, Messungen der Proteinexpression sowie Stabilitätsassays zur funktionellen Validierung von Varianteneffekten. Ein zentraler mechanistischer Befund ist, dass Störungen sehr spät in der kodierenden Sequenz sich anders verhalten können, als einfache Modelle vorhersagen: Einige Transkripte entgehen dem erwarteten nonsense-mediated decay (NMD) und können die Proteinstabilität verändern. Diese experimentell validierten Erkenntnisse haben direkte Bedeutung für diagnostische Interpretation, Neugeborenen-Screening und Genotyp-Phänotyp-Korrelation bei SMA.

Fazit:

Prof. Wirths Karriere zeigt, dass die experimentelle Validierung von Spleiß- und Proteinstabilitäts-Effekten von SMN1/SMN2-Varianten für eine präzise klinische Interpretation bei SMA essenziell ist.

Musik:

Genieße die Musik, die auf diesem Beitrag basiert, am Ende der Episode.

Support:

Base by Base – Stripe-Spenden: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Offizielle Website: https://basebybase.com

Bei PaperCast Base by Base entdeckst du Aktuelles aus Genomik, funktioneller Genomik, struktureller Genomik und Proteomik.

Episodenlink: basebybase.com/episodes/smn1-smn2-splicing-wirth-2/

302: SMN1/SMN2 splicing and last-exon mechanisms — Tribute to Brunhilde Wirth

Gustavo Barra — Thu, 26 Feb 2026 13:33:18 +0000

The Last Exon Light: A Tribute Dossier Celebrating the Scientific Career of Prof. Dr. Brunhilde Wirth - Special tribute episode honoring Prof. Dr. Brunhilde Wirth and synthesizing recurring themes across her work on SMN1/SMN2 splicing, variant interpretation, and spinal muscular atrophy.

Study Highlights:
This special episode is based on a tribute dossier rather than a single new primary research paper. It highlights recurring scientific themes across Brunhilde Wirth's career: SMN1/SMN2 biology, exon splicing, functional validation of variants, nonsense-mediated decay edge cases, and genotype-phenotype interpretation in SMA.

Conclusion:
This release should be read as an editorial tribute and curated scientific overview, not as a summary of one canonical article.

Music:
Enjoy the music based on this article at the end of the episode.

Source document:
The Last Exon Light: A Tribute Dossier Celebrating the Scientific Career of Prof. Dr. Brunhilde Wirth

Source type:
Editorial tribute dossier / multi-source compilation

Reference:
The Last Exon Light: A Tribute Dossier Celebrating the Scientific Career of Prof. Dr. Brunhilde Wirth. Editorial tribute dossier and curated retrospective source text.

License:
Not specified in the provided text.

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/smn1-smn2-splicing-wirth

QC:
This episode was reviewed as a special editorial release.

QC Scope:
- source-document framing, descriptive metadata, and publication text
- excludes automated single-article AI QC because this episode is a curated tribute dossier / multi-source compilation rather than one canonical research paper
- title, framing, and source attribution were reviewed manually

QC Summary:
- production mode: editorial tribute / multi-source compilation
- single-article AI QC: not applicable
- listener note: this episode synthesizes a tribute dossier celebrating Brunhilde Wirth's scientific career and related SMA/splicing themes

Metadata Audited:
- episode_title
- source_document_title
- source_type
- reference
- license

Factual Items Audited:
- episode explicitly framed as a tribute dossier / multi-source compilation
- no single canonical research article is represented as the sole source
- publication description was aligned to dossier-style source material
- manual editorial review approved the release

QC result: Editorial exception. This episode was approved after manual review.

Chapters

(00:00:10) - The End of an Era in Genetic Science
(00:01:57) - The discovery of SMN2 in spinal cord disease
(00:06:13) - The journey from bench to bed
(00:08:00) - The mystery of SMA
(00:12:18) - A Legacy of SMA: Katherine Worth's work
(00:15:31) - Stitch the Science Into Life

301: Biobank Mendelian randomization prioritizes 6,447 genes and nominates ANXA2 for dyslipidemia

Gustavo Barra — Wed, 25 Feb 2026 05:43:41 +0000

Ferolito BR et al., Human Genetics and Genomics Advances, 7 (2026) 100556. doi:10.1016/j.xhgg.2025.100556 - Meta-analysis of MVP, UK Biobank and FinnGen with Mendelian randomization using eQTL/pQTL instruments implicates 6,447 genes and 69,669 causal gene-trait links. Key terms: Mendelian randomization, biobank meta-analysis, pQTL, drug target discovery, machine learning ranking.

Study Highlights:
The authors meta-analyzed GWAS from MVP, UK Biobank, and FinnGen across 2,003 harmonized phenotypes and used cis-eQTLs and cis-pQTLs from GTEx, eQTLGen, ARIC, Fenland, and deCODE to perform two-sample Mendelian randomization. They identified 69,669 significant gene-trait pairs (p ≤ 1.6×10⁻⁹) representing 6,447 genes with strong causal evidence and performed colocalization and sensitivity analyses to assess concordance. An XGBoost classifier trained on ChEMBL-derived approved targets and engineered biological features achieved a precision-recall AUC of 0.79 to rank MR hits by likelihood of clinical success. The resource yields rediscoveries and repurposing leads (e.g., ANXA2 nominated for lipid regulation) and supplies a prioritized list for downstream target evaluation.

Conclusion:
Integrating >1.2 million individuals' GWAS from large biobanks with eQTL/pQTL Mendelian randomization and orthogonal annotations yields 69,669 candidate causal gene-trait links and a machine-learning ranking that prioritizes targets for drug development.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Leveraging large-scale biobanks for therapeutic target discovery

First author:
Ferolito BR

Journal:
Human Genetics and Genomics Advances, 7 (2026) 100556. doi:10.1016/j.xhgg.2025.100556

DOI:
10.1016/j.xhgg.2025.100556

Reference:
Ferolito BR, Dashti H, Giambartolomei C, Peloso GM, Golden DJ, Gravel-Pucillo K, Rasooly D, Horimoto ARV R, Matty R, Gaziano L, Liu Y, Smit IA, Zdrazil B, Tsepilov Y, Costa L, Kosik N, Huffman JE, Tartaglia GG, Bini G, Proietti G, Ioannidis H, Karim MA, Hunter F, Hemani G, Butterworth AS, Di Angelantonio E, Langenberg C, Ghoussaini M, Leach AR, Liao KP, Damrauer S, Selva LE, Whitbourne S, Tsao PS, Moser J, Gaunt T, Cai T, Whittaker JC, Million Veteran Program, Casas JP, Muralidhar S, Gaziano JM, Cho K, Pereira AC. Leveraging large-scale biobanks for therapeutic target discovery. Human Genetics and Genomics Advances. 7 (2026) 100556. https://doi.org/10.1016/j.xhgg.2025.100556.

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/biobank-mendelian-randomization-targets

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-02-25.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript portions describing Mendelian randomization (MR) as a nature-encoded trial, biobank meta-analysis (MVP/UKBB/FinnGen), molecular instruments (cis-eQTL/pQTL), concordant signal filtering, ML ranking, rediscovery/repurposing highlights, and lipid-target case study with ANXA2.
- transcript topics: Mendelian randomization as a natural clinical trial; Biobank meta-analysis (MVP, UKBB, FinnGen) and phenome-wide scope; cis-eQTL and cis-pQTL instrument sources; Two-sample MR and concordant-instrument filtering; XGBoost classifier for target prioritization; Drug rediscovery and repurposing (ANXA2, PCSK9, HMGCR)

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- 69,669 gene-trait pairs with strong causal evidence (p ≤ 1.6×10⁻⁹)
- 6,447 genes with strong causal evidence across 2,003 phenotypes
- rediscovered ~9% of approved drug targets in ChEMBL34
- ML ranking classifier (XGBoost) with precision-recall AUC = 0.79
- ANXA2 nominated as a lipid-regulation target and acts via PCSK9 inhibition
- Trastuzumab-associated cardiotoxicity flagged as a risk

QC result: Pass.

300: Population-scale WGS links MHC class II antigen presentation to persistent Epstein–Barr virus (EBV) DNA

Gustavo Barra — Tue, 24 Feb 2026 08:32:58 +0000

Nyeo SS et al., Nature, doi:10.1038/s41586-025-10020-2 - Population-scale WGS reanalysis quantifies persistent EBV DNA and shows MHC class II–mediated antigen presentation predicts EBV DNAemia and links to autoimmune and respiratory disease. Key terms: Epstein–Barr virus, MHC class II, whole-genome sequencing, HLA, antigen presentation.

Study Highlights:
Using whole-genome sequencing from UK Biobank (n≈490,560) and All of Us (n≈245,394), the authors extracted chrEBV-mapping reads, masked low-mappability regions, and defined EBV DNAemia (>1.2 genomes per 10^4 cells) in 9.7–11.9% of donors. They performed PheWAS, GWAS and ExWAS and identified 22 genome-wide significant loci and 686 missense variants across 148 genes with heritability enrichment in immune regulatory regions and B cells/antigen-presenting cells. Single-cell module scoring, pathway analyses and NetMHCpan/NetMHCIIpan peptide-presentation modeling implicated variable antigen processing and MHC class II presentation as primary determinants of EBV persistence, with stronger predicted presentation linked to lower EBV DNAemia. EBV DNAemia was reproducibly associated with autoimmune, respiratory, neurological and cardiovascular phenotypes across cohorts.

Conclusion:
Reanalysis of population-scale WGS demonstrates that host genetic variation—predominantly in antigen processing and MHC class II peptide presentation—modulates persistent EBV DNA in blood and associates with multiple complex diseases.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Population-scale sequencing resolves determinants of persistent EBV DNA

First author:
Nyeo SS

Journal:
Nature, doi:10.1038/s41586-025-10020-2

DOI:
10.1038/s41586-025-10020-2

Reference:
Nyeo SS, Cumming EM, Burren OS, Pagadala MS, Gutierrez JC, Ali TA, Kida LC, Chen Y, Chu H, Hu F, Zou XZ, Hollis B, Fabre MA, MacArthur S, Wang Q, Ludwig LS, Dey KK, Petrovski S, Dhindsa RS & Lareau CA. Population-scale sequencing resolves determinants of persistent EBV DNA. Nature. 2026 Feb 19;650:664–672. https://doi.org/10.1038/s41586-025-10020-2

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/ebv-mhc-class-ii

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-02-24.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the spoken content for core EBV DNAemia measurement, population-scale findings, genetic architecture (GWAS/ExWAS), MHC class II/HLA roles, peptide presentation modeling, cell-type enrichment, phenotype associations, viral genome considerations, and replication across UKB and AoU.
- transcript topics: Definition and measurement of EBV DNAemia from population-scale WGS; Population-scale prevalence in UKB and AoU, threshold and binarization; Genome-wide and exome-wide association results (22 loci; 686 missense variants in 148 genes); Role of MHC class II and HLA variation in EBV DNAemia; Specific HLA alleles: HLA-A*03:01 risk; HLA-DRB1*12:01 protection; NetMHC/NetMHCIIpan predictions and HBR-based antigen presentation

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- EBV DNAemia is quantified from chrEBV reads in population-scale WGS; threshold set at 1.2 EBV genomes per 10^4 human cells
- UKB prevalence of EBV DNAemia: 9.7% (47,452 individuals); AoU replication prevalence: 11.9%
- Genome-wide analysis identified 22 independent loci associated with EBV DNAemia; 686 missense variants across 148 genes
- Heritability enriched in immune regulatory regions; pronounced enrichment in B cells and antigen-presenting cells
- HLA region drives strongest genetic associations; HLA-A*03:01 increases risk; HLA-DRB1*12:01 is protective
- Predicted EBV epitope presentation strength by MHC class II alleles correlates with lower EBV DNAemia; class II alleles show strongest associations

QC result: Pass.

299: UFM1 loss and R81C mutation disrupt neuronal translation, ER stress, and synaptogenesis

Gustavo Barra — Tue, 24 Feb 2026 07:53:09 +0000

Perdigão C et al., EMBO Molecular Medicine, doi:10.1038/s44321-026-00389-6 - In mouse neurons, UFM1 loss or UFM1-R81C expression reduces protein translation, triggers ER stress and PERK activation, impairing dendrite and synapse development. Key terms: UFM1, UFMylation, ER stress, protein translation, Trazodone.

Study Highlights:
Using murine UFM1-deficient neurons generated by conditional knockout and CRISPR/Cas9 in vivo manipulations and lentiviral rescue, the study combined FUNCAT, puromycin labeling, patch-clamp electrophysiology, RNA-seq, mass spectrometry, TEM tomography, and in vitro UFMylation assays. UFM1 loss caused reduced dendrite complexity, a ~70% drop in colocalized synaptic puncta, decreased EPSC amplitudes and RRP size, induction of ER stress and PERK-UPR activation, and a substantial reduction in global protein translation. The UFM1-R81C variant was hypomorphic: it partially rescued morphology and function but showed drastically impaired activation by the E1 enzyme UBA5 and an aggravated ER-stress response to thapsigargin. Pharmacologically, Trazodone normalized translation in UFM1-R81C neurons and increased synapse numbers in both UFM1-KO and UFM1-R81C conditions, linking UPR/translation modulation to phenotypic rescue.

Conclusion:
UFMylation is required for neuronal development and function: UFM1 loss and the UFM1-R81C variant impair protein translation and ER homeostasis, and Trazodone restores translation in UFM1-R81C neurons while increasing synapse numbers.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Encephalopathy-linked UFM1 variants impede neuronal protein translation, development, and function

First author:
Perdigão C

Journal:
EMBO Molecular Medicine, doi:10.1038/s44321-026-00389-6

DOI:
10.1038/s44321-026-00389-6

Reference:
Perdigão C, Torres J, Magnussen HM, Koch J, Rudashevskaya E, Moschref F, Fiosins M, Benseler F, Wenger S, Nilsson T, Beuermann S, Bonn S, Rizzoli SO, Kulathu Y, Jahn O, Cooper BH, Ambrozkiewicz MC, Rhee JS, Brose N & Tirard M (2026) Encephalopathy-linked UFM1 variants impede neuronal protein translation, development, and function. EMBO Molecular Medicine. https://doi.org/10.1038/s44321-026-00389-6

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/ufm1-r81c-neuronal-translation

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-02-24.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited core scientific claims and experimental findings presented in the episode and mapped them to the paper's results: UFM1 loss causes reduced dendritic complexity and synapses, reduced translation; UFM1-R81C is hypomorphic with reduced UBA5 activation; PERK-UPR activation; Trazodone rescues translation and increas
- transcript topics: UFMylation pathway and enzymes (UFM1, UBA5, UFC1, UFL1); UFM1 loss: neuronal development and synapse reduction; UFM1-R81C variant mechanism; ER stress and PERK-UPR activation; Protein translation assessment (FUNCAT, puromycin); Trazodone rescue effects on translation and synapses

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 5
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- UFM1 loss reduces dendritic complexity and synapse numbers and lowers EPSC amplitudes and RRP size
- Global protein translation is reduced in UFM1-KO neurons
- UFM1 loss induces ER stress and activates the PERK-UPR pathway
- UFM1-R81C is hypomorphic with reduced activation by UBA5 and only partial rescue, with aggravated ER stress under challenge
- Trazodone restores translation in UFM1-R81C neurons and increases synapse numbers in both UFM1-KO and UFM1-R81C neurons

QC result: Pass.

298: Bi-allelic FSD1L variants in retinitis pigmentosa implicate photoreceptor axoneme

Gustavo Barra — Tue, 24 Feb 2026 06:14:05 +0000

Lin S et al., The American Journal of Human Genetics, Corrected proof. doi:10.1016/j.ajhg.2026.01.015 - Bi-allelic FSD1L variants cause retinitis pigmentosa; FSD1L localizes to the photoreceptor axoneme and a deep intronic deletion abolishes retina-enriched exon 10b inclusion. Key terms: FSD1L, retinitis pigmentosa, photoreceptor axoneme, exon 10b, minigene assay.

Study Highlights:
In human and mouse retinal tissues and six affected individuals from four families, exome/genome sequencing identified bi-allelic ultra-rare FSD1L variants associated with retinitis pigmentosa. Single-cell RNA-seq, immunofluorescence, and ultrastructure expansion microscopy show FSD1L is enriched in cones and rods and localizes along the photoreceptor microtubule axoneme including the connecting cilium and outer segment. Functional assays including ARPE-19 minigene splicing and long-read nanopore sequencing of patient lymphocytes demonstrate that a deep intronic 26-nt deletion abolishes inclusion of a retina-enriched exon (exon 10b). Together these data link isoform-specific mis-splicing and axonemal localization to a plausible disruption of intracellular trafficking leading to photoreceptor degeneration.

Conclusion:
Bi-allelic disruption of FSD1L is associated with retinitis pigmentosa, and retina-enriched exon 10b mis-splicing provides a plausible mechanism for isolated retinal disease.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Bi-allelic variants in FSD1L cause retinitis pigmentosa with or without neurological involvement

First author:
Lin S

Journal:
The American Journal of Human Genetics, Corrected proof. doi:10.1016/j.ajhg.2026.01.015

DOI:
10.1016/j.ajhg.2026.01.015

Reference:
Lin S., Cancellieri F., Cao Y., et al. Bi-allelic variants in FSD1L cause retinitis pigmentosa with or without neurological involvement. The American Journal of Human Genetics 113, 1–11 (2026). https://doi.org/10.1016/j.ajhg.2026.01.015

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/fsd1l-retinitis-pigmentosa-axoneme

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-02-24.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited substantive scientific content in the transcript: discovery of bi-allelic FSD1L variants in RP families; retina-enriched isoform with exon 10b; deep intronic deletion disrupting exon 10b; minigene splicing assays; FSD1L localization to photoreceptor axoneme/connecting cilium/outer segment; expression pattern in
- transcript topics: RP and inherited retinal disease overview; FSD1L as RP gene candidate; Retina-enriched isoform and exon 10b; Deep intronic deletion c.1025+624_1025+649del and exon 10b skipping; Minigene splicing assays in ARPE-19 cells; FSD1L localization to photoreceptor axoneme via U-ExM

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Bi-allelic ultra-rare FSD1L variants identified in six individuals from four families
- FSD1L expression enriched in cone photoreceptors (and present in rods) in human retina
- FSD1L localizes along the photoreceptor microtubule axoneme, including the connecting cilium and outer segment
- Retina-enriched isoform includes exon 10b; deep intronic deletion disrupts exon 10b inclusion
- Minigene splicing assays show exon 10b skipping with the intronic deletion
- Clinical spectrum includes RP with variable neurological involvement; isoform- and allele-specific effects explain phenotypic variability

QC result: Pass.

297: Bi-allelic FSD1L variants disrupt mitotic spindle and ciliogenesis in an L1-like neurodevelopmental disorder

Gustavo Barra — Tue, 24 Feb 2026 05:42:50 +0000

Serpieri V et al., The American Journal of Human Genetics, Corrected proof. doi:10.1016/j.ajhg.2026.01.014 - Bi-allelic FSD1L variants disrupt a microtubule-associated protein, causing hydrocephalus, corpus callosum defects and an L1 syndrome-like neurodevelopmental disorder in humans and models. Key terms: FSD1L, microtubules, ciliogenesis, hydrocephalus, iPSC neuronal differentiation.

Study Highlights:
Exome sequencing in eleven affected individuals (including five fetuses) identified bi-allelic FSD1L variants associated with hydrocephalus and corpus callosum defects. Using iPSC-derived neural progenitor differentiation, neurosphere assays, patient fibroblasts, immunohistochemistry, and in utero CRISPR-Cas9 mouse knockdown, the authors show that FSD1L localizes to mitotic spindle microtubules and to the transition zone/axoneme of the primary cilium. Patient NPCs fail to differentiate into premature neurons, undergo increased cell death, and form smaller disorganized neurospheres, while patient fibroblasts show abnormal spindles, reduced ciliogenesis and shorter cilia. Fsd1l repression in mouse embryos produced lateral ventricular dilation, functionally linking FSD1L to mitotic spindle assembly, ciliogenesis, neuronal differentiation and axon guidance.

Conclusion:
Bi-allelic pathogenic variants in FSD1L cause a neurodevelopmental syndrome overlapping L1 syndrome by disrupting a microtubule-associated protein required for mitotic spindle assembly, ciliogenesis, and neuronal differentiation.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Bi-allelic variants in FSD1L cause a neurodevelopmental disorder overlapping with L1 syndrome

First author:
Serpieri V

Journal:
The American Journal of Human Genetics, Corrected proof. doi:10.1016/j.ajhg.2026.01.014

DOI:
10.1016/j.ajhg.2026.01.014

Reference:
Serpieri V., Vezain-Mouchard M., Orsi A., et al. Bi-allelic variants in FSD1L cause a neurodevelopmental disorder overlapping with L1 syndrome. The American Journal of Human Genetics. 113, 1–16 (March 5, 2026). https://doi.org/10.1016/j.ajhg.2026.01.014

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/fsd1l-microtubule-ciliogenesis

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-02-24.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript’s presentation of the AJHG 2026 FSD1L study’s main claims, cellular mechanisms, experimental models, and clinical implications as described in the article.
- transcript topics: Clinical features resembling L1 syndrome; Gene discovery via exome sequencing and GeneMatcher; Autosomal recessive inheritance; FSD1L as a microtubule-associated protein localizing to mitotic spindle and primary cilium; iPSC-derived neural progenitor differentiation defects; Fibroblast spindle abnormalities and ciliogenesis defects

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Bi-allelic FSD1L variants identified in 11 affected individuals from six unrelated families
- FSD1L localizes to mitotic spindle microtubules and to the primary cilium transition zone/axoneme
- iPSC-derived neural progenitor cells from affected individuals failed to differentiate into premature neurons and showed increased cell death
- Patient fibroblasts exhibited abnormal mitotic spindles and reduced ciliogenesis with shorter cilia
- Fsd1l repression in mouse embryos produced ventriculomegaly (lateral ventricular dilation)
- Phenotype closely resembles L1 syndrome; overlapping expression patterns with L1CAM in developing brain

QC result: Pass.

296: snaR-A ncRNA antagonizes U2 snRNP SF3B2 to drive intron retention in human cells

Gustavo Barra — Sat, 21 Feb 2026 08:56:17 +0000

Zhou S et al., Nature Communications, doi:10.1038/s41467-025-65448-x - snaR-A noncoding RNA interacts with U2 snRNP subunit SF3B2 and nuclear speckles, increasing intron retention and promoting proliferation in human cancer-relevant cells. Key terms: snaR-A, SF3B2, intron retention, nuclear speckles, RNA polymerase III.

Study Highlights:
Using human cell lines (HEK293T, A549, THP-1) and tumor chromatin data, the authors combined biotinylated RNA pulldown mass spectrometry, PAR-CLIP/CLIP-qPCR, HCR-RNA-FISH, TSA-seq, and ultra-deep RNA-seq (IRFinder, rMATS) to map snaR-A interactions and splicing outcomes. snaR-A directly binds splicing factors and shows nucleotide-level crosslinking to the U2 snRNP protein SF3B2, and localizes to subnuclear foci adjacent to nuclear speckles and U6-containing sites. Functionally, snaR-A overexpression increases intron retention and selectively depletes SF3B2 protein, whereas snaR-A depletion reduces intron retention for transcripts with high U2 occupancy and speckle proximity. These splicing changes alter protein abundance for multiple targets and coincide with reduced proliferation after snaR-A depletion, consistent with tumor-level associations to growth.

Conclusion:
snaR-A acts as a molecular antagonist of U2-dependent splicing by interacting with SF3B2 and perturbing processing of specific mRNA subpopulations, promoting intron retention and proliferation in cancer-relevant contexts.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Cancer-associated snaR-A noncoding RNA interacts with core splicing machinery and disrupts processing of mRNA subpopulations

First author:
Zhou S

Journal:
Nature Communications, doi:10.1038/s41467-025-65448-x

DOI:
10.1038/s41467-025-65448-x

Reference:
Zhou S., Lizarazo S., Chorghade S., Mouli L., Cheng R., Rajendra K. C., Kalsotra A., Van Bortle K. Cancer-associated snaR-A noncoding RNA interacts with core splicing machinery and disrupts processing of mRNA subpopulations. Nature Communications. 2025;16:10460. https://doi.org/10.1038/s41467-025-65448-x

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/snar-a-sf3b2-splicing

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-02-21.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript’s presentation of the snaR-A study: interaction with SF3B2 and U2 snRNP, localization to nuclear speckles, intron retention effects, SF3B2 protein depletion, depletion effects on splicing and protein abundance, proliferation/migration phenotypes, TCGA prognosis, and limitations.
- transcript topics: snaR-A interaction with SF3B2 and U2 snRNP; localization of snaR-A to nuclear speckles and proximity to U6; snaR-A-induced intron retention and splicing disruption; SF3B2 protein depletion upon snaR-A overexpression; snaR-A depletion reduces IR in U2-residency, speckle-proximal transcripts; OGFR and other targets affected by splicing changes

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- snaR-A ncRNA interacts with SF3B2, a core U2 snRNP component
- snaR-A localizes to subnuclear foci near nuclear speckles and U6
- overexpression of snaR-A increases intron retention (IR)
- snaR-A overexpression reduces SF3B2 protein levels
- snaR-A depletion reduces IR for transcripts with high U2 residency and speckle proximity
- splicing changes lead to altered protein abundance for targets including OGFR

QC result: Pass.

295: CFTR deltaF508 and CF-risk variants protect against IBD in large exome study

Gustavo Barra — Thu, 19 Feb 2026 21:02:11 +0000

Yu M et al., Cell Genomics, 6 (2026) 101071. doi:10.1016/j.xgen.2025.101071 - Large-scale exome sequencing shows CFTR risk variants, including deltaF508, reduce susceptibility to inflammatory bowel disease, suggesting targeted CFTR modulation as a potential IBD therapy. Key terms: CFTR, deltaF508, inflammatory bowel disease, exome sequencing, rare-variant burden test.

Study Highlights:
The authors analyzed large-scale human exome and genome sequencing data (38,558 cases and 66,945 controls in European discovery; 42,475 cases and 192,050 controls in replication across ancestries) using single-variant tests and gene-based rare-variant burden tests. They report a protective single-variant association for CFTR deltaF508 with IBD (meta-analysis p = 8.96E-11, OR = 0.82) and a significant protective gene-level burden of clinically annotated CF-risk variants (meta-analysis p = 3.9E-7, OR = 0.85). The study also compared variant prioritization methods and found clinically curated CFTR2 annotations outperform in silico predictors such as AlphaMissense for powering burden tests. Replication signals were observed in non-European groups at nominal significance and the results support exploration of selective, tissue-targeted CFTR modulators as a potential therapeutic implication.

Conclusion:
Clinically annotated CFTR risk variants, including deltaF508, confer a reproducible protective effect against IBD in large sequencing cohorts, supporting investigation of selective tissue-targeted CFTR modulation while balancing cystic fibrosis risks.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Cystic fibrosis risk variants confer protection against inflammatory bowel disease

First author:
Yu M

Journal:
Cell Genomics, 6 (2026) 101071. doi:10.1016/j.xgen.2025.101071

DOI:
10.1016/j.xgen.2025.101071

Reference:
Yu M., Zhang Q., Yuan K., Sazonovs A., Stevens C.R., Fachal L., et al. Cystic fibrosis risk variants confer protection against inflammatory bowel disease. Cell Genomics. 6 (2026) 101071. https://doi.org/10.1016/j.xgen.2025.101071

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/cftr-deltaf508-ibd-protection

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-02-19.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the Results and Discussion segments of the transcript, including the DeltaF508 association with IBD, CFTR2-based burden tests, replication across ancestries, AlphaMissense evaluation and mechanistic discussion about mucus and BEST4+ enterocytes, and therapeutic implications.
- transcript topics: CFTR deltaF508 single-variant association with IBD; CFTR2-based rare-variant burden test; negative control with non-CF-risk variants; ancestry-adjusted analysis and replication (EUR, AFR.AMR, EAS); CFTR variant prioritization: AlphaMissense vs CFTR2; mechanistic discussion: mucus hydration and BEST4+ enterocytes

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- CFTR deltaF508 single-variant protective effect against IBD (OR 0.82; p 8.96E-11)
- CF-risk variants burden test shows protective effect against IBD (OR 0.85; p 3.9E-07)
- CD/UC subtype effects: deltaF508 protective stronger for CD (OR ~0.79) than UC (OR ~0.87)
- Exclusion of homozygous deltaF508 to avoid CF misclassification
- Cross-ancestry replication across AFR.AMR and EAS groups
- CFTR2-based burden variants outperform AlphaMissense for burden tests

QC result: Pass.

294: Alternative splicing, exonization and lineage-specific isoforms: PTBP1, MAPT and TE-derived exons in mammalian evolution

Gustavo Barra — Wed, 18 Feb 2026 22:18:49 +0000

Hunter CE et al., The EMBO Journal, doi:10.1038/s44318-025-00666-z - Review shows how alternative splicing, via TE exonization and cis-regulatory changes and revealed by long-read RNA-seq, reshapes gene regulation and drives phenotypic evolution in mammals. Key terms: alternative splicing, exonization, long-read RNA-seq, microexons, comparative transcriptomics.

Study Highlights:
This review synthesizes comparative transcriptomic studies across multicellular eukaryotes with emphasis on vertebrates and mammals. It highlights methods including short- and long-read RNA-seq, single-cell transcriptomics, and MS proteomics to map isoform diversity. The authors emphasize that lineage-specific AS is often driven by cis-regulatory changes and exonization of transposable elements, with trans-factor innovations (e.g., SRRM3/4, PTBP1 isoforms) modulating microexons and isoform ratios. Functional examples linking AS to phenotypes include an Alu-derived IFNAR2 decoy receptor reducing JAK/STAT signaling, TNNI3 exon3 loss or skipping associated with extreme heart rates, and hominoid shifts in MAPT exon10 splicing altering tau isoform proportion.

Conclusion:
Alternative splicing, shaped largely by cis-sequence changes and TE exonization and illuminated by long-read and single-cell transcriptomics, is a flexible evolutionary mechanism that can produce lineage-specific regulatory and phenotypic innovations.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
The splice of life: how alternative splicing shapes regulatory and phenotypic evolution

First author:
Hunter CE

Journal:
The EMBO Journal, doi:10.1038/s44318-025-00666-z

DOI:
10.1038/s44318-025-00666-z

Reference:
Hunter CE, Xing Y. The splice of life: how alternative splicing shapes regulatory and phenotypic evolution. The EMBO Journal. 2026. https://doi.org/10.1038/s44318-025-00666-z

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/alternative-splicing-exonization-evolution

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-02-18.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Substantively audited sections covering splicing mechanisms, exonization and TE-derived exons, three main evolutionary modes of AS, cis vs trans regulation, sequencing technologies (long-read, single-cell, proteomics), and case studies (TBXT tail loss, TNNI3, MAPT). Also reviewed Tc1 humanized mouse results and immune/
- transcript topics: Basics of alternative splicing and spliceosome regulation; Exon creation via TE exonization (Alu elements) and exonization examples (IFNAR2); Exon loss and splicing level changes as evolutionary modes; Three case studies: TBXT tail loss via exon skipping; TNNI3 exon 3 loss/skip for high heart rate; MAPT exon 10 splicing and tau isoforms; Cis-regulatory vs trans-acting factors in splicing evolution (Tc1 human chromosome 21 study); Splicing regulators and microexons (SRRM3/4, PTBP1) and their evolutionary implications

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 5
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Exon creation via transposable elements (TE exonization) contributes new exons (e.g., Alu-derived exons in immune genes like IFNAR2)
- Exon loss or skipping (e.g., TBXT exon 6) can drive phenotypic changes such as tail loss in hominoids
- Splicing-level changes (altered inclusion of exons) can reshape isoform outputs without changing gene presence
- MAPT exon 10 splicing, modulated by MBNL, shifts tau isoform ratios (3R/4R) and is linked to lineage-specific brain features
- Cis-regulatory changes predominantly drive lineage-specific AS patterns; Tc1 mouse study shows human exon splicing is recapitulated by cis elements rather than trans factors

QC result: Pass.

293: IndeLLM (ESM2) zero-shot scoring and Siamese transfer learning for in-frame indel prediction (MCC 0.77)

Gustavo Barra — Tue, 17 Feb 2026 10:21:31 +0000

Gracia Carmona O et al., Patterns, 7 (2026) 101425. doi:10.1016/j.patter.2025.101425 - IndeLLM uses protein language models (ESM2) to score in-frame indels and a compact Siamese transfer-learning model that achieves state-of-the-art pathogenicity prediction with MCC = 0.77. Key terms: IndeLLM, protein language models, in-frame indels, Siamese network, ESM2.

Study Highlights:
Using human protein sequences and ESM2 embeddings, the authors develop IndeLLM, a zero-shot scoring function that sums overlapping-region probabilities to correct length bias in in-frame indels. They train a compact Siamese one-hidden-layer network on PLM embeddings with biologically guided embedding splitting and achieve MCC = 0.77 on the test set. Per-residue probability differences mapped onto structures (FGFR1, GLMN) identify local regions affected by indels and improve interpretability. The framework reduces insertion false negatives and is released with Colab and GitHub tools for indel annotation and disease-variant analysis.

Conclusion:
IndeLLM zero-shot scoring and a small Siamese transfer-learning model provide improved, interpretable indel pathogenicity prediction, with the Siamese model achieving MCC = 0.77.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Leveraging protein language models and a scoring function for indel characterization and transfer learning

First author:
Gracia Carmona O

Journal:
Patterns, 7 (2026) 101425. doi:10.1016/j.patter.2025.101425

DOI:
10.1016/j.patter.2025.101425

Reference:
Gracia Carmona O, Leipart V, Amdam GV, Orengo C, Fraternali F. Leveraging protein language models and a scoring function for indel characterization and transfer learning. Patterns. 7 (2026) 101425. https://doi.org/10.1016/j.patter.2025.101425

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/indellm-indel-siamese-model

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-02-17.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the scientific content conveyed in the transcript: indel biology, IndeLLM zero-shot scoring, Siamese Model 4, performance metrics, interpretability via structure-mapped probability changes, structural validation with AlphaFold, and broad applicability including non-human systems and accessible tooling.
- transcript topics: Indel biology: in-frame indels vs frameshift indels; Protein language models and length bias; Indel scoring: IndeLLM zero-shot (overlapping regions); Probability scoring math: sum vs log-sum; Siamese network (Model 4) and transfer learning; Performance metrics: MCC 0.65 (zero-shot) and 0.77 (Siamese); comparison to Provean

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- IndeLLM zero-shot scoring uses overlapping regions to correct length bias
- Switch from log probability sums to sum of probabilities to reduce noise
- Model 4 Siamese network with embedding splitting achieves MCC 0.77
- Zero-shot MCC is 0.65 and outperforms Brandes scoring (0.58); comparable to supervised methods
- Per-residue probability differences mapped to FGFR1 and GLMN explain pathogenicity; AlphaFold used for validation
- Honeybee example demonstrates generalizability beyond humans

QC result: Pass.

292: INS R6C signal-peptide defect reduces preproinsulin ER translocation in iPSC-derived βcells

Gustavo Barra — Tue, 17 Feb 2026 09:29:18 +0000

Tong Y et al., EMBO Molecular Medicine, doi:10.1038/s44321-025-00362-9 - Patient data, population genetics and iPSC-derived βcell models show INS R6C impairs preproinsulin ER translocation and causes recessive insulin-deficient diabetes in homozygotes. Key terms: INS R6C, preproinsulin translocation, iPSC-derived beta cells, monogenic diabetes, population genetics.

Study Highlights:
The study integrates clinical pedigrees, large-scale population screens and patient-derived iPSC βcell models, plus in vivo transplantation and transcriptomics. AlphaFold 3 structural modeling suggested weakened SRP54 interaction and altered SEC61 orientation for the R6C signal peptide, and population data showed no enrichment of diabetes among heterozygotes. In homozygous R6C iPSC-βcells up to two-thirds of nascent preproinsulin failed to translocate, preproinsulin accumulated, and insulin content and secretion were reduced by roughly 50% with altered proinsulin processing. Functionally, homozygous R6C grafts produced minimal human C-peptide in mice and responded poorly to GLP-1 receptor agonists, while heterozygotes were largely compensated by a single wild-type allele.

Conclusion:
INS R6C is a recessive loss-of-function mutation that causes early-onset, insulin-deficient diabetes in homozygotes while heterozygous carriers show variable or absent glycemic phenotypes.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
A new form of diabetes caused by INS mutations defined by zygosity, stem cell and population data

First author:
Tong Y

Journal:
EMBO Molecular Medicine, doi:10.1038/s44321-025-00362-9

DOI:
10.1038/s44321-025-00362-9

Reference:
Tong Y, Becker M, Schierloh U, Natividade da Silva F, Haataja L, Cai Y, Patel KA, Kobaisi F, Mirshahi UL, Colclough K, Javed MS, Wakeling MN, Fantuzzi F, Lytrivi M, Sawatani T, Arroyo MN, Yi X, Vinci C, Montaser H, Pachera N, Otonkoski T, Igoillo-Esteve M, Scharfmann R, Hattersley AT, Arvan P, De Beaufort C, Cnop M. A new form of diabetes caused by INS mutations defined by zygosity, stem cell and population data. EMBO Molecular Medicine. 2026;18:620–645. https://doi.org/10.1038/s44321-025-00362-9

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/ins-r6c-recessive-diabetes

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-02-17.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the core scientific narrative conveyed in the transcript, focusing on: INS R6C zygosity-dependent diabetes; ER translocation defect caused by the signal peptide; SRP54 and SEC61 translocon involvement; heterozygous vs homozygous iPSC-derived β-cell phenotypes; population-genetic evidence; in vivo transplantatio
- transcript topics: INS R6C mutation and zygosity; ER translocation defect and signal peptide mechanism; SRP54 and SEC61 translocon interactions; iPSC-derived β-cell modeling (heterozygous and homozygous); In vivo transplantation and C-peptide outcomes; Population genetics data (UK Biobank, Geisinger) and penetrance

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Homozygous INS R6C causes early-onset diabetes with greatly reduced insulin production; two bad INS alleles impair ER translocation of preproinsulin (≈66% translocation loss; ≈50%
- Heterozygous R6C carriers show limited cellular defects with insulin secretion near normal; modest preproinsulin accumulation and altered proinsulin processing but preserved overal
- ER translocation defect is driven by R6C’s effect on signal peptide properties; AlphaFold modeling suggests weakened SRP54 interaction and inverted SEC61 orientation, reducing ER t
- Population data indicate no strong enrichment of diabetes in heterozygous carriers (UK Biobank: no diabetes among heterozygotes; Geisinger: odds ratio ~1.4 with wide CI).
- GLP-1 receptor agonists improve glucose metrics in homozygotes only modestly and do not restore insulin secretion; insulin replacement remains the primary therapy for homozygous R6
- Clinical counseling implications: reclassify INS R6C from dominant to recessive; emphasize penetrance variability and environmental modifiers (e.g., obesity, pregnancy).

QC result: Pass.

290: SMN1 p.Arg288AlafsTer5 exon 7 deletions evade PCR newborn screening yet yield functional SMN isoform

Gustavo Barra — Sun, 15 Feb 2026 23:01:35 +0000

Wirth B et al., The American Journal of Human Genetics, Corrected proof. doi:10.1016/j.ajhg.2026.01.012 - Two SMN1 exon 7 4-bp deletions (p.Arg288AlafsTer5) evade standard PCR newborn screening but produce a low-abundance, thermostable SMN protein that functionally rescues smn1-deficient zebrafish and averted therapy. Key terms: SMN1, spinal muscular atrophy, newborn screening, p.Arg288AlafsTer5, zebrafish rescue.

Study Highlights:
In two clinically healthy newborns flagged as lacking SMN1 by PCR-based NBS, long-range SMN1-specific PCR, Sanger sequencing, MLPA and ddPCR identified distinct 4-bp exon 7 deletions producing the same frameshift p.Arg288AlafsTer5. Cellular assays showed preserved exon 7 splicing, markedly reduced SMN protein abundance, and unchanged protein thermostability, while AlphaFold3 predicted only mild C-terminal structural alteration. Functional complementation in smn1-deficient zebrafish—using both mRNA injection and a stable Tg(UBI-mKate_SMN1-861VUS) transgene—fully rescued morphology, motor behavior, and survival. Population gnomAD analysis indicates these variants are rare but present in Europeans at a carrier frequency that predicts hundreds of compound heterozygotes without reported SMA, informing diagnostic sequencing and avoidance of unnecessary therapy.

Conclusion:
Integrated genetic, functional, structural, and population-level evidence supports likely non-pathogenic reclassification of the SMN1 c.855_858delAGAA and c.861_864delAAGG alleles and shows that very low levels of the altered SMN protein can preserve normal motor development.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
SMN1 variants identified by false-positive SMA newborn screening tests: Therapeutic hurdles and functional and epidemiological solutions

First author:
Wirth B

Journal:
The American Journal of Human Genetics, Corrected proof. doi:10.1016/j.ajhg.2026.01.012

DOI:
10.1016/j.ajhg.2026.01.012

Reference:
Wirth B., Das J., Kölbel H., Goh S., Farrar M.A., Piano V., Zetzsche S., Fuhrmann N., Becker J., Karakaya M., Zhang Y., Cao Y., Taghipour-Sheshdeh A., Stringer B.W., Giacomotto J., et al. SMN1 variants identified by false-positive SMA newborn screening tests: Therapeutic hurdles and functional and epidemiological solutions. The American Journal of Human Genetics. 2026 Mar 5;113:1–9. https://doi.org/10.1016/j.ajhg.2026.01.012

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/smn1-exon7-frameshift-variants

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-02-15.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript sections describing the two SMN1 exon 7 4-bp deletions, their molecular consequences, splicing, protein abundance and thermostability, in vivo zebrafish rescue, and population-genetics data with implications for clinical practice.
- transcript topics: Identification of two SMN1 exon 7 4-bp deletions; Molecular confirmation and variant characterization; SMN1 exon 7 splicing preservation; SMN protein abundance and thermostability assessments; Zebrafish functional rescue experiments; Population genetics (gnomAD) data and carrier frequencies

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Two SMN1 exon 7 4-bp deletions (c.855_858delAGAA and c.861_864delAAGG) produce p.Arg288AlafsTer5
- Deletions disrupt the NBS primer-binding site, explaining initial SMN1 signal loss in screening
- Exon 7 splicing is preserved; SMN1 transcripts are full-length with no exon 7 skipping
- SMN protein abundance is markedly reduced in carriers
- Mutant SMN1 proteins are thermostable and structurally similar to WT
- In vivo zebrafish experiments show functional rescue by SMN1-855VUS and SMN1-861VUS

QC result: Pass.

291: Dated gene duplications show Asgard archaeal host complexity before mitochondrial endosymbiosis

Gustavo Barra — Sun, 15 Feb 2026 23:01:35 +0000

Kay CJ et al., Nature, doi:10.1038/s41586-025-09808-z - Relaxed-clock dating of pre-LECA gene duplications in Asgard archaeal and alphaproteobacterial lineages shows a complex archaeal host with cytoskeleton, endomembrane system and nucleus before mitochondrial acquisition around 2.2 Ga. Key terms: eukaryogenesis, Asgard archaea, mitochondrial endosymbiosis, gene duplication, molecular clock.

Study Highlights:
The study interrogates eukaryogenesis using a time-resolved species tree and a sequential Bayesian relaxed molecular clock applied to 135 gene family trees. Analyses with MCMCTree dated divergence nodes (nFECA 3.05–2.79 Ga, mFECA 2.37–2.13 Ga, LECA 1.80–1.67 Ga) and pre-LECA duplication events of archaeal and bacterial origin. Most archaeal-derived duplications (about 85% of those sampled) were fixed prior to inferred mitochondrial endosymbiosis, with archaeal duplications for actin, tubulin, vesicle trafficking and spliceosomal components dated between ~3.0 and ~2.25 Ga. Functionally, these timings indicate the host lineage had an elaborated cytoskeleton, endomembrane trafficking and nuclear compartmentalization before mitochondrial integration, while alphaproteobacterial duplications cluster near ~2.2 Ga consistent with mitochondrial establishment.

Conclusion:
Gene-duplication dating supports a complexified archaeal host with cytoskeleton, endomembrane system and nucleus preceding mitochondrial endosymbiosis, favoring a late-mitochondrion model of eukaryogenesis.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Dated gene duplications elucidate the evolutionary assembly of eukaryotes

First author:
Kay CJ

Journal:
Nature, doi:10.1038/s41586-025-09808-z

DOI:
10.1038/s41586-025-09808-z

Reference:
Kay CJ, Spang A, Szöllősi GJ, Pisani D, Williams TA & Donoghue PCJ. Dated gene duplications elucidate the evolutionary assembly of eukaryotes. Nature 650, 129–140 (2026). https://doi.org/10.1038/s41586-025-09808-z

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/asgard-archaea-duplication-timeline

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-02-15.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript sections that describe the eukaryogenesis timeline, gene duplication events, and the CALM model, including specific date ranges and functional system developments (cytoskeleton, endomembrane system, nucleus, mitochondrion).
- transcript topics: Eukaryogenesis timeline and debate (mitochondria early vs late); Relaxed molecular clock and cross-bracing dating approach; Pre-LECA duplications in archaeal origin (cytoskeleton, nucleus, trafficking); Endomembrane system and vesicle trafficking gene duplications; Nuclear components and RNA polymerase duplications; Mitochondrial endosymbiosis timing and alphaproteobacterial duplications

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Pre-LECA host features (cytoskeleton, endomembrane system, nucleus) existed before mitochondrial endosymbiosis
- nFECA divergence 3.05–2.79 Ga
- mFECA divergence 2.37–2.13 Ga
- LECA divergence 1.80–1.67 Ga
- Alphaproteobacterial duplications associated with mitochondrial endosymbiosis (~2.2 Ga)
- 85% of pre-LECA archaeal-origin duplicates fixed before mitochondrial endosymbiosis

QC result: Pass.

290 auf Deutsch: SMN1-Exon-7-Deletionen p.Arg288AlafsTer5 entgehen dem PCR-Neugeborenenscreening und erzeugen dennoch eine funktionelle SMN-Isoform

Gustavo Barra — Sat, 14 Feb 2026 12:33:00 +0000

Wirth B et al. (The American Journal of Human Genetics, 2026) — Zwei 4-bp-Deletionen in Exon 7 von SMN1 (p.Arg288AlafsTer5) entgehen dem Standard-PCR-Neugeborenenscreening, erzeugen jedoch ein SMN-Protein in sehr geringer Menge, das thermostabil ist, smn1-defiziente Zebrafische funktionell rettet und eine Therapie vermeiden half.

Studien-Highlights:
• Zwei klinisch gesunde Neugeborene wurden im PCR-basierten Neugeborenenscreening (NBS) fälschlich als „ohne SMN1“ auffällig.
• In der Bestätigungsdiagnostik (SMN1-spezifische Long-Range-PCR + Sanger-Sequenzierung + MLPA + ddPCR) wurden zwei unterschiedliche 4-bp-Deletionen in Exon 7 identifiziert, die denselben Frameshift erzeugen: p.Arg288AlafsTer5.
• Zellbasierte Assays zeigten erhaltenes Exon-7-Spleißen, eine deutlich reduzierte SMN-Proteinmenge und eine unveränderte Protein-Thermostabilität.
• AlphaFold3 sagte nur eine milde strukturelle Veränderung am C-Terminus voraus.
• In-vivo-funktionelle Komplementation im smn1-defizienten Zebrafisch (mRNA-Injektion + stabile Tg(UBI-mKate_SMN1-861VUS)-Transgenlinie) rettete Morphologie, Motorik und Überleben vollständig.
• Populationsanalyse (gnomAD) legt nahe, dass diese Varianten in Europäern selten, aber vorhanden sind, mit einer Trägerfrequenz, die mit Hunderten von Compound-Heterozygoten ohne registrierte SMA vereinbar ist — ein Argument für diagnostische Sequenzierung und die Vermeidung unnötiger Therapie.

Schlussfolgerung:
Integrierte genetische, funktionelle, strukturelle und populationsbasierte Evidenz unterstützt eine wahrscheinlich nicht-pathogene Reklassifizierung der SMN1-Allele c.855_858delAGAA und c.861_864delAAGG und zeigt, dass sehr niedrige Mengen des veränderten SMN-Proteins eine normale motorische Entwicklung erhalten können.

Musik:
Genieße am Ende der Episode die Musik, die auf diesem Artikel basiert.

Referenz:
Wirth B., Das J., Kölbel H., Goh S., Farrar M.A., Piano V., Zetzsche S., Fuhrmann N., Becker J., Karakaya M., Zhang Y., Cao Y., Taghipour-Sheshdeh A., Stringer B.W., Giacomotto J., et al.
SMN1 variants identified by false-positive SMA newborn screening tests: Therapeutic hurdles and functional and epidemiological solutions.
The American Journal of Human Genetics. 2026 Mar 5;113:1–9. https://doi.org/10.1016/j.ajhg.2026.01.012

Lizenz:
Diese Episode basiert auf einem Open-Access-Artikel, der unter der Creative Commons Attribution 4.0 International License (CC BY 4.0) veröffentlicht wurde:
https://creativecommons.org/licenses/by/4.0/

Unterstützung:
Base by Base – Stripe-Spenden:
https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Offizielle Website:
https://basebybase.com

289: MinION detection of chimeric reads in murine Ifna/Ifnb amplicons and ligation-related artifact prevalence

Gustavo Barra — Fri, 13 Feb 2026 08:06:08 +0000

White R et al., F1000Research - Investigation of chimeric reads in MinION nanopore sequencing of short PCR amplicons, focusing on ligation-related artifacts, barcode tracing, and the prevalence of cross-gene chimeras in murine Ifna/Ifnb sequencing runs.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Investigation of chimeric reads using the MinION

First author:
White R

Journal:
F1000Research

DOI:
10.12688/f1000research.11547.2

Reference:
White R, Pellefigues C, Ronchese F, Lamiable O, Eccles D. Investigation of chimeric reads using the MinION [version 2; peer review: 2 approved]. F1000Research. 2017;6:631. https://doi.org/10.12688/f1000research.11547.2

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

QC:
This episode was reviewed as a special editorial release.

QC Scope:
- human-authored narration, music, and publication metadata
- excludes automated single-article AI QC because this episode was not produced by the standard AI narration pipeline
- source attribution and descriptive metadata were reviewed manually

QC Summary:
- production mode: human-written and human-produced episode
- automated transcript-vs-paper AI QC: not applicable
- metadata, source attribution, and release assets were reviewed manually

Metadata Audited:
- article_doi
- article_title
- article_journal
- reference
- license

Factual Items Audited:
- episode classified as a human-produced release
- canonical human narration retained as the source of record
- canonical human-produced music retained as the source of record
- automated NotebookLM regeneration intentionally not used for this episode

QC result: Editorial exception. This episode was approved after manual review.

288: Cryo-EM of rat cerebellar α1/α6 GABAA receptors reveals PZ‑II‑029 binding and β-α-β-α-γ assemblies

Gustavo Barra — Thu, 12 Feb 2026 06:20:49 +0000

Sun C et al., Proc. Natl. Acad. Sci. U.S.A. 2026.123:e2524504123 - Using cryo-EM and mass spectrometry in rat cerebellum, α1- and α6-containing GABAA receptor assemblies (β‑α‑β‑α‑γ stoichiometry) and PZ-II-029 binding were defined. Key terms: GABAA receptor, cerebellum, α6 subunit, cryo-EM, pyrazoloquinolinone.

Study Highlights:
The study used rat cerebellum tissue and combined confocal immunofluorescence, affinity purification with mass spectrometry, and high-resolution cryo-EM to characterize native α1-containing GABAA receptors. Cryo-EM classification resolved eight distinct α1-containing receptor assemblies that conform to a conserved β-α-β-α-γ arrangement and include previously unreported α6-containing heteromers. Structural models of α6-containing receptors show near-symmetric ECD architecture with conserved GABA-binding geometry and distinct electrostatic differences that may affect ligand kinetics. Binding of the α6-selective pyrazoloquinolinone PZ-II-029 at α+/γ− pockets was visualized and found to induce coordinated outward expansion of the extracellular domain, providing a structural basis for subtype-selective modulation.

Conclusion:
Native α1-containing cerebellar GABAA receptors adopt a conserved β-α-β-α-γ pentameric scaffold that includes α6 subunits and binds PZ-II-029 at α+/γ− sites, producing extracellular domain expansion.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Molecular assemblies and pharmacology of cerebellar GABAA receptors

First author:
Sun C

Journal:
Proc. Natl. Acad. Sci. U.S.A. 2026.123:e2524504123

DOI:
10.1073/pnas.2524504123

Reference:
Sun C, Jahncke JN, Wright KM, Gouaux E. Molecular assemblies and pharmacology of cerebellar GABAA receptors. Proc. Natl. Acad. Sci. U.S.A. 2026;123:e2524504123. Published February 6, 2026. https://doi.org/10.1073/pnas.2524504123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/cerebellar-gabaa-alpha6-assemblies

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-02-12.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited sections cover GABAAR architecture, cerebellar α1/α6 coassembly, native purification and mass spectrometry, cryo-EM assembly identification, PZ-II-029 binding and allosteric effects, ligand-pocket differences, and study limitations.
- transcript topics: GABAAR architecture and subunit diversity; Cerebellar distribution of α1 and α6 subunits and mixed α1/α6 assemblies; Native cerebellar receptor purification, nanodisc reconstitution, and mass spectrometry findings; Cryo-EM identification of eight cerebellar GABAAR assemblies and β2-α1-β1-α6-γ2 configuration; PZ-II-029 binding at α+/γ− pockets (α1/γ2 and α6/γ2) and structural consequences; Ligand-induced extracellular-domain expansion and intersubunit distance changes

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Native cerebellar GABAARs include mixed α1 and α6 subunits forming β2-α1-β1-α6-γ2 assemblies
- Eight distinct cerebellar GABAAR assemblies were identified, all conforming to a β-α-β-α-γ scaffold
- PZ-II-029 binds at benzodiazepine pockets at α+/γ− interfaces, including α1/γ2 and α6/γ2 pockets, with site-specific interactions
- PZ-II-029 binding induces expansion of the extracellular domain and increases intersubunit distances across subunits
- Ki of PZ-II-029 is about 4.2 ± 0.4 nM in cerebellar receptor preparations
- Delta subunit is detected by mass spectrometry but is not resolved in cryo-EM reconstructions; delta-containing assemblies remain unresolved

QC result: Pass.

287: EPOP and MTF2 modulate PRC2 H3K27me3 deposition via GA- and GCN-sequence specificity

Gustavo Barra — Wed, 11 Feb 2026 05:30:52 +0000

Granata J et al., Proc. Natl. Acad. Sci. U.S.A. 2026.123:e2527303123 - In mESCs and defined in vitro assays, EPOP and MTF2 stimulate PRC2 methyltransferase activity and promote de novo H3K27me3 deposition with GA- or GCN-rich DNA preference. Key terms: EPOP, MTF2, PRC2, H3K27me3, DNA-sequence specificity.

Study Highlights:
The study used mouse embryonic stem cells with an EED-rescue system and recombinant in vitro assays including HMT assays, EMSA, and ChIP-seq to probe EPOP and MTF2 function. Biochemical HMT assays on oligonucleosomes and dinucleosomes show both EPOP and MTF2 directly stimulate PRC2 catalytic activity, with MTF2 preferentially enhancing activity and binding on GCN-rich linkers and EPOP on GA-rich linkers. ChIP-seq during EED rescue demonstrated that EPOP is dispensable for initial PRC2 recruitment but its knockout reduces de novo H3K27me3 deposition by ~50% and cooperates with MTF2 and JARID2. Together these data indicate linker DNA sequence within nucleation sites guides subcomplex-specific PRC2 binding and catalytic output, influencing spatial establishment of H3K27me3 domains.

Conclusion:
EPOP and MTF2 define distinct PRC2 subcomplexes that stimulate PRC2 catalytic activity in a chromatin-dependent, DNA-sequence-specific manner to direct de novo H3K27me3 deposition.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
EPOP and MTF2 activate PRC2 activity through DNA-sequence specificity

First author:
Granata J

Journal:
Proc. Natl. Acad. Sci. U.S.A. 2026.123:e2527303123

DOI:
10.1073/pnas.2527303123

Reference:
Granata J., Liu S., Popoca L., Oksuz O., Reinberg D. EPOP and MTF2 activate PRC2 activity through DNA-sequence specificity. Proc. Natl. Acad. Sci. U.S.A. 2026;123:e2527303123. https://doi.org/10.1073/pnas.2527303123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/epop-mtf2-prc2-sequence

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-02-11.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited transcript segments describing PRC2 function, EPOP/MTF2 cofactors, in vitro histone methyltransferase (HMT) assays, the EED rescue system and de novo recruitment, dinucleosome substrates with GA- and GCN-rich linker DNA, EMSA binding data, and the rheostat model of cofactors shaping genome-wide H3K27me3 pattern
- transcript topics: PRC2 function and H3K27me3 deposition; EPOP and MTF2 as PRC2 cofactors; In vitro PRC2 histone methyltransferase assays; EED rescue system and de novo PRC2 recruitment; Dinucleosome substrates with GA- and GCN-rich linker DNA; EMSA nucleosome binding and affinity

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- EPOP and MTF2 stimulate PRC2 histone methyltransferase (HMT) activity in vitro
- EPOP is dispensable for de novo PRC2 recruitment; MTF2 is essential for de novo recruitment
- EPOP knockout reduces de novo H3K27me3 deposition in vivo by ~50%
- GA-rich linker DNA favors EPOP; GC-rich (GCN) linker DNA favors MTF2 in dinucleosome contexts
- GA- and GCN-dinucleotide results reflect substrate-context (chromatin) specificity, not naked DNA binding
- EPOP requires nucleosomal DNA context to exhibit GA preference; naked GA DNA shows no preference

QC result: Pass.

286: Deep mutational scanning of Nipah virus fusion protein F reveals functional and antigenic constraints

Gustavo Barra — Tue, 10 Feb 2026 09:03:20 +0000

Larsen BB et al., Proc. Natl. Acad. Sci. U.S.A. 2026.123:e2529505123 - Deep mutational scanning of the Nipah virus fusion protein F using pseudoviruses maps ~8,500 single-residue effects, showing F is highly constrained and identifying antibody-escape mutations. Key terms: Nipah virus, fusion protein F, deep mutational scanning, pseudovirus, antibody neutralization.

Study Highlights:
Using nonreplicative lentiviral pseudoviruses and deep mutational scanning, the authors measured the effects of 8,449 single amino-acid mutations to the Nipah virus F ectodomain on cell entry in CHO cells expressing bat ephrin-B3. Measurements were fit with global epistasis models and mapped onto prefusion and postfusion structures, revealing the fusion peptide, lateral surface patches, and hexameric-interface residues are highly constrained. The library was screened against six monoclonal antibodies, quantifying mutation-mediated decreases in neutralization and showing distinct resilience among antibodies; specific Hendra F residues (Q70K, R336K) explained loss or reduction of neutralization by 4H3 and 1A9. The data nominate candidate proline substitutions and other sites for prefusion stabilization and inform vaccine and therapeutic antibody selection.

Conclusion:
Nipah virus F is highly functionally constrained relative to RBP with specific surface-exposed and core residues critical for cell entry, and antibody neutralization varies by epitope, informing prefusion-stabilized immunogen and therapeutic antibody design.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Functional and antigenic constraints on the Nipah virus fusion protein

First author:
Larsen BB

Journal:
Proc. Natl. Acad. Sci. U.S.A. 2026.123:e2529505123

DOI:
10.1073/pnas.2529505123

Reference:
Larsen BB, Harari S, Gen R, Stewart C, Veesler D, Bloom JD. Functional and antigenic constraints on the Nipah virus fusion protein. Proc. Natl. Acad. Sci. U.S.A. 2026;123:e2529505123. https://doi.org/10.1073/pnas.2529505123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/nipah-f-deep-mutational-map

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-02-10.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the scientific content presented in the transcript, focusing on Nipah virus F deep mutational scanning, functional/antigenic constraints, structural interpretation, stabilizing mutations, antibody resilience, and translational implications.
- transcript topics: Nipah virus F structure and function; Deep mutational scanning methodology; Pseudovirus system with bat ephrin receptors; Mutational constraint landscape of Nipah F; Fusion peptide and hexamer interface regions; Prefusion stabilization via proline mutations

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Nipah F is highly constrained; mutations mostly impair function
- Deep mutational scanning tested 8,449 single amino acid mutations (~98.2% coverage)
- F is more functionally constrained than RBP (RBP more mutationally tolerant)
- Fusion peptide and lateral surface/hexamer interfaces are highly constrained
- Proline substitutions can stabilize prefusion F (candidate stabilizing mutations identified)
- Monoclonal antibodies show varying resilience to F mutations; 1F2 and 2D3 retain neutralization more broadly

QC result: Pass.

285: ESBX (Tb927.3.1660) integrates ESB RNA Pol I localization with BES activation and VSG repression in Trypanosoma brucei

Gustavo Barra — Mon, 09 Feb 2026 05:19:48 +0000

Berazategui MA et al., Proc. Natl. Acad. Sci. U.S.A. 2026.123:e2531377123 - ESBX (Tb927.3.1660) links RNA Pol I localization at the ESB to activation of the active BES and repression of inactive BESs in Trypanosoma brucei, supporting monoallelic VSG expression. Key terms: Trypanosoma brucei, ESBX (Tb927.3.1660), expression site body, variant surface glycoprotein, RNA polymerase I.

Study Highlights:
Using ESB1-guided proximity-dependent biotinylation proteomics, endogenous tagging and high-resolution fluorescence microscopy, RNAi knockdown, RNA-seq, and inducible overexpression in bloodstream-form Trypanosoma brucei, the authors identify Tb927.3.1660 (ESBX) as an ESB-specific protein. ESBX localizes adjacent to Pol I (RPA2) and ESB1 within the ESB with measured center separations of ~68–175 nm and contains predicted SUMO-interacting and BRCT domains. ESBX depletion causes loss of the extranucleolar Pol I ESB focus, reduced processive transcription from the active BES with larger decreases distal to the promoter, and derepression of inactive BESs with low-processivity transcripts, whereas ESBX overexpression weakly activates inactive BESs with processive transcription without forming extra ESBs. Together the data indicate ESBX integrates activation of the active BES with repression of inactive BESs, a mechanism that supports monoallelic VSG expression.

Conclusion:
Tb927.3.1660/ESBX is an ESB component required to integrate activation of the active BES with repression of inactive BESs, thereby supporting monoallelic VSG expression in bloodstream-form Trypanosoma brucei.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
A factor integrating transcription and repression of surface antigen genes in African trypanosomes

First author:
Berazategui MA

Journal:
Proc. Natl. Acad. Sci. U.S.A. 2026.123:e2531377123

DOI:
10.1073/pnas.2531377123

Reference:
Berazategui MA, Wheeler RJ, Tiengwe C, Lansink LIM, Rudenko G, Sunter JD, Goodwin I, Gull K, Faria JRC, et al. A factor integrating transcription and repression of surface antigen genes in African trypanosomes. Proc. Natl. Acad. Sci. U.S.A. 2026.123:e2531377123. https://doi.org/10.1073/pnas.2531377123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/esbx-esb-vsg-regulation

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-02-09.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited sections cover ESBX identification, ESB localization, functional knockdown and overexpression phenotypes, BRCT domain/phase separation discussion, transcriptional state model, and broader implications; not audited are full experimental methods or supplementary data in detail.
- transcript topics: ESBX identification by proximity labeling and transcriptomics; ESBX localization to ESB near Pol I, ESB1, VEX2; ESBX depletion effects: growth arrest, ESB disassembly, active BES down, inactive BES derepression; ESBX overexpression effects: activation of inactive BESs, no extra ESBs; BRCT domains and phase separation notion for ESBX; Transcriptional state model: FE state, trickle state, enhanced trickle (ET)

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- ESBX is Tb927.3.1660 and functions as an ESB component
- ESBX links transcriptional activation of the active BES with repression of inactive BESs
- ESBX depletion leads to ESB disassembly and loss of RNA Pol I at the ESB
- Inactive BES transcripts are derepressed upon ESBX depletion
- ESBX overexpression activates inactive BESs with processive transcription without forming extra ESBs
- ESBX is likely upstream of ESB1 and influences VEX2/ VEX-mediated exclusion

QC result: Pass.

284: FES, VSMC behavior and pleiotropic vascular genes identified by integrative functional genomics

Gustavo Barra — Sun, 08 Feb 2026 09:29:57 +0000

Solomon CU et al., Nat Commun(2026). - Integrative analysis in human VSMCs identifies pleiotropic genes including FES that regulate vascular remodeling; pooled CRISPR and mouse knockout show FES loss increases MMPs, atherosclerosis and blood pressure. Key terms: FES, vascular smooth muscle cell, atherosclerosis, colocalization eQTL, CRISPR knockout screen.

Study Highlights:
The study used a large human umbilical cord‑derived VSMC eQTL bank (n=1,486) combined with colocalization (eCAVIAR, SMR/HEIDI), ATAC‑seq, DNA methylation, H3K27ac HiChIP and pooled CRISPR‑Cas9 knockout screens to nominate likely causal genes for CAD, hypertension, stroke and AAA. Pooled CRISPR screens and siRNA validation in VSMCs highlighted BCAR1, CARF, SMARCA4 and FES as modulators of VSMC proliferation or migration, while FES knockdown increased MMP1/MMP3, reduced contractile markers and promoted migration by RNA‑seq and proteomics/phosphoproteomics. In vivo, Fes‑/-/Apoe‑/- mice had larger en face aortic lesion areas (8.34±2.54% vs 6.06±2.35%, P=0.013) and higher baseline systolic/diastolic blood pressure (104.4±6.7 vs 88.0±10.1 mmHg and 74.9±9.0 vs 58.8±8.9 mmHg, P=0.042). These results support FES as a pleiotropic, potentially druggable regulator of VSMC phenotype with functional effects on atherosclerosis and blood pressure.

Conclusion:
Integrative functional genomics implicates panels of likely causal and pleiotropic genes, including FES, that regulate VSMC behavior and whose loss promotes VSMC dedifferentiation, increased MMP production, larger atherosclerotic lesions and higher blood pressure.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Integrative functional genomics analysis identifies pleiotropic genes for vascular diseases

First author:
Solomon CU

Journal:
Nat Commun(2026).

DOI:
10.1038/s41467-026-69273-8

Reference:
Solomon CU, McVey DG, Andreadi C, Peng G, Turner L, Song DSS, Zhang H, Lee DP, Karamanavi E, Yang W, Chu J, Chen R, Haworth KE, Anene-Nzelu CG, Li H, Denniff MJ, Li PY, Zhang Y, Huang X, Morris GE, Greer PA, Stringer EJ, Yu H, Foo RSY, Douglas G, Samani NJ, Webb TR, Ye S. Integrative functional genomics analysis identifies pleiotropic genes for vascular diseases. Nat Commun (2026). https://doi.org/10.1038/s41467-026-69273-8

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/fes-vsmc-pleiotropic-genes

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-02-08.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited substantive portions of the transcript describing FES as a pleiotropic regulator of vascular disease, VSMC phenotypic switching, CRISPR knockouts, mouse model results, UK Biobank human genetics, and therapeutic implications.
- transcript topics: Pleiotropy across vascular diseases; FES as a master regulator in vascular smooth muscle cells (VSMCs); VSMC phenotypic switching, migration, and MMP production; Pooled CRISPR-Cas9 knockout screens and validation; Mouse model: Fes knockout and atherosclerosis/blood pressure; UK Biobank human genetics for FES variants

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 5
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- FES is identified as a pleiotropic gene affecting more than one vascular disease (CAD and hypertension).
- FES knockdown in vascular smooth muscle cells increases migration and production of matrix metalloproteinases (MMPs) and decreases contractile markers.
- Fes knockout mice on a high-fat diet show larger atherosclerotic lesions and elevated baseline blood pressure, with impaired vasodilation responses.
- UK Biobank data show deleterious FES variants associate with higher blood pressure and increased risks of hypertension and myocardial infarction.
- A set of pleiotropic genes (including FES) was identified; several are druggable and might be targeted to affect multiple vascular diseases.

QC result: Pass.

283: Confidence in genetic knowledge drives Familiarity, Knowledge, and Skills in US GALS samples

Gustavo Barra — Sat, 07 Feb 2026 06:17:52 +0000

Ramírez Renta GM et al., The American Journal of Human Genetics, 113 (2026) 16-28. doi:10.1016/j.ajhg.2025.11.014 - GALS survey of >4,000 US respondents (GenPop and SPARK) shows confidence in genetic knowledge predicts Familiarity, Knowledge, and Skills, explaining ~25% of variance. Key terms: genetic literacy, confidence in knowledge, GALS, SPARK, science communication.

Study Highlights:
Using the Genetic and Autism Literacy Survey (GALS) in two US samples (GenPop and SPARK; n>4,000), the authors measured three genetic literacy components: Familiarity, Knowledge, and Skills via subjective familiarity ratings, objective true/false items, and a comprehension task. They modeled associations between these subscales and identity/belief measures including perceived importance, confidence, religiosity, religious affiliation, and political belief using linear regression adjusted for education and population. Confidence in one’s genetic knowledge was the strongest predictor, accounting for roughly 25% of variance in Familiarity and Knowledge and substantially improving model R2; perceived importance had a positive but smaller effect while religious and political measures showed mixed associations. The finding implies improving individuals’ confidence in genetic knowledge, alongside tailored communication strategies, could support better comprehension and uptake of genetics and genomics services.

Conclusion:
Confidence in one’s genetic knowledge, after education, is the largest modifiable predictor of genetic literacy and should be a focus for interventions to improve comprehension and uptake of genetics services.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Interaction of identity and beliefs with genetic literacy

First author:
Ramírez Renta GM

Journal:
The American Journal of Human Genetics, 113 (2026) 16-28. doi:10.1016/j.ajhg.2025.11.014

DOI:
10.1016/j.ajhg.2025.11.014

Reference:
Ramírez Renta GM, Little ID, Koehly LM, et al. Interaction of identity and beliefs with genetic literacy. The American Journal of Human Genetics. 2026;113:16–28. https://doi.org/10.1016/j.ajhg.2025.11.014

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/genetic-literacy-confidence-gals

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-02-07.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript’s presentation of core scientific claims: the three GL pillars (Familiarity, Knowledge, Skills), cultural cognition framework, GALS sampling (GenPop and SPARK), key findings on confidence as predictor, religion/politics effects, disengagement, and implications for communication and trust.
- transcript topics: Genetic literacy pillars (Familiarity, Knowledge, Skills); Cultural cognition theory and identity filtering; GALS methodology and cohorts (GenPop vs SPARK); Confidence as a key predictor (~25% variance in GL scores); Religion/religiosity and science vs religion conflict effects; Political beliefs and GL differences

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Genetic literacy comprises three components: Familiarity, Knowledge, and Skills.
- Confidence in one’s genetic knowledge is the strongest predictor of GL scores, accounting for about 25% of the variance.
- Religious affiliation and religiosity are negative predictors of GL scores (relative to non-religious groups).
- When faced with science-religion conflict, participants who chose science had higher GL scores than those who chose religion.
- Liberals show higher GL scores across subscales than conservatives or moderates; conservatives differ mainly on Knowledge.
- SPARK participants scored higher on GL measures than GenPop participants.

QC result: Pass.

282: Gene-specific variance-control corrects polygenicity-driven inflation in TWAS

Gustavo Barra — Fri, 06 Feb 2026 04:26:15 +0000

Liang Y et al., The American Journal of Human Genetics, 113 (2026) 276-290. doi:10.1016/j.ajhg.2025.12.014 - TWAS using genetically predicted expression exhibit polygenicity-driven inflation that increases with GWAS sample size and heritability; a gene-specific variance-control correction yields calibrated p values. Key terms: transcriptome-wide association study, TWAS, polygenicity, variance-control, PrediXcan.

Study Highlights:
The authors evaluated TWAS and related xWAS using simulated polygenic null traits and UK Biobank genotypes with predicted mediators including gene expression, metabolites, and brain features. They combined large-scale simulations, theoretical derivations, and empirical regression of mean Z2 on N*h2δ to estimate a gene-specific inflation slope Φ and applied corrections with S‑PrediXcan/PrediXcan across 110 GWAS traits. They show analytically and empirically that Var(Z) ≈ 1 + N*h2δ*Φ, observe a cohort-level slope around 4.2×10^-5, and demonstrate that dividing Z by sqrt(1+N*h2δ*Φ) restores calibration. Applying the variance-control correction yields well-calibrated p values, reduces false positives for highly polygenic traits, and improves precision with minimal loss of power.

Conclusion:
A gene-specific variance-control correction based on an empirically estimated inflation slope Φ corrects polygenicity-driven inflation in TWAS/xWAS and yields calibrated false-positive rates in simulations and real GWAS analyses.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
A gene-specific variance-control approach corrects polygenicity-driven inflation observed in transcriptome-wide association studies

First author:
Liang Y

Journal:
The American Journal of Human Genetics, 113 (2026) 276-290. doi:10.1016/j.ajhg.2025.12.014

DOI:
10.1016/j.ajhg.2025.12.014

Reference:
Liang Y, Nyasimi F, Im HK. A gene-specific variance-control approach corrects polygenicity-driven inflation observed in transcriptome-wide association studies. The American Journal of Human Genetics. 113 (2026) 276-290. https://doi.org/10.1016/j.ajhg.2025.12.014

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/twas-variance-control-inflation

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-02-06.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Substantive audit of the transcript’s treatment of TWAS inflation, the Phi inflation parameter, the variance-control correction, and real-data validation across multiple data modalities.
- transcript topics: TWAS/xWAS inflation due to polygenicity; linear scaling of inflation with sample size and trait heritability; gene-specific inflation parameter Phi (Φ); variance-control correction and Z-score calibration (Zcorr = Ztwas / sqrt(1 + Φ N h2δ)); comparison with BACON correction; simulation framework: polygenic null trait; UK Biobank data usage across metabolites and brain features

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- TWAS/xWAS inflation increases with polygenicity
- Inflation scales linearly with GWAS sample size and trait heritability
- Gene-specific inflation parameter Phi (Φ) modulates inflation per gene
- Variance-control method calibrates Z-scores by adjusting with sqrt(1 + Φ N h2δ)
- Variance-control yields calibrated p-values and reduces false positives in polygenic contexts
- Real-data validation across 110 GWAS traits and across metabolites/brain features

QC result: Pass.

281: Variant-level mapping of ACTB and ACTG1 defines eight non-muscle actinopathies and links BWCFF to actin polymerization defects

Gustavo Barra — Fri, 06 Feb 2026 04:10:55 +0000

Di Donato N et al., The American Journal of Human Genetics, 113 (2026) 324-341. doi:10.1016/j.ajhg.2025.12.007 - Analysis of 290 individuals with ACTB and ACTG1 variants defines eight distinct non-muscle actinopathies and links BWCFF-causing variants to altered actin polymerization dynamics. Key terms: ACTB, ACTG1, Baraitser-Winter, actin polymerization, genotype-phenotype.

Study Highlights:
The study assembled a clinical-genomic cohort of 290 individuals with P/LP ACTB or ACTG1 variants and used expert phenotyping plus GestaltMatcher facial analysis to delineate eight distinct non-muscle actinopathies. Complementary methods included patient-derived fibroblast transcriptomics, recombinant actin production, differential scanning fluorimetry, and pyrene-based polymerization/depolymerization assays. BWCFF-associated missense variants (e.g., ACTB:R196H, ACTG1:T203M) produced decreased polymerization rates and faster depolymerization, whereas selected ACTB missense or in-frame variants impaired folding or thermal stability consistent with loss-of-function. These mechanistic stratifications support improved diagnostic classification, prognostication, and selection of functional assays for variant interpretation.

Conclusion:
Variant-level analysis of 290 individuals delineates eight distinct non-muscle actinopathies and shows that BWCFF-linked missense variants disrupt actin polymerization while select ACTB variants cause protein instability consistent with loss-of-function.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Molecular genotype-phenotype correlation in ACTB- and ACTG1-related non-muscle actinopathies

First author:
Di Donato N

Journal:
The American Journal of Human Genetics, 113 (2026) 324-341. doi:10.1016/j.ajhg.2025.12.007

DOI:
10.1016/j.ajhg.2025.12.007

Reference:
Di Donato N, NMA Consortium, et al. Molecular genotype-phenotype correlation in ACTB- and ACTG1-related non-muscle actinopathies. The American Journal of Human Genetics. 113:324-341 (2026). https://doi.org/10.1016/j.ajhg.2025.12.007

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/actb-actg1-non-muscle-actinopathies

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-02-06.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the substantive scientific content of the transcript, focusing on: gene pair ACTB/ACTG1; eight NMAs; BWCFF mechanistic basis (actin polymerization/depolymerization); loss-of-function ACTB with thrombocytopenia; ACTG1 deletion phenotypes; fibroblast/tissue specificity; GestaltMatcher-based facial analysis; diagn
- transcript topics: ACTB and ACTG1 gene similarity and functional differences; Cohort overview: 290 individuals, 125 new cases; Eight non-muscle actinopathies (NMAs) and genotype-phenotype correlations; BWCFF mechanism: missense variants cause unstable actin, altered polymerization/depolymerization; ACTB loss-of-function (LoF) disorder: thrombocytopenia and neurodevelopmental features; ACTG1 deletions: milder phenotypes or near-normal presentations

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Cohort comprises 290 individuals with ACTB/ACTG1 variants (125 new cases)
- Eight distinct non-muscle actinopathies (NMAs) identified
- BWCFF associated with missense variants showing decreased actin polymerization and faster depolymerization
- ACTB loss-of-function (LoF) variants/deletions associated with thrombocytopenia and mild neurodevelopmental impairment
- ACTG1 deletions often milder or near-normal; dosage sensitivity lower than ACTB
- Dystonia-deafness syndrome (ACTB hotspot variants like R183W) and isolated hearing loss (ACTG1) described

QC result: Pass.

280: SCD, FADS and a 3p25.2 (PPARG) locus shape fatty acid composition in human subcutaneous adipose tissue

Gustavo Barra — Wed, 04 Feb 2026 05:38:29 +0000

Yan X et al., The American Journal of Human Genetics, Corrected proof. doi:10.1016/j.ajhg.2025.12.008 - In 569 TwinsUK subcutaneous adipose biopsies, twin models and GWAS identify SCD, FADS and 3p25.2 (PPARG) loci regulating fatty acid levels and conversions. Key terms: SCD, FADS1, PPARG, adipose-tissue, fatty-acids.

Study Highlights:
System and sample: 569 female TwinsUK subcutaneous adipose biopsies with matched serum, RNA-seq and 450K methylation data were analyzed. Key methods: gas chromatography fatty acid profiling, ACE twin heritability models, GWAS of 18 fatty acids and 15 product-to-precursor ratios, colocalization with adipose eQTLs and meQTLs, and polygenic score analysis. Main quantitative results: heritability of individual fatty acids ranged from 5%–59% while 15 fatty acid ratios were heritable and GWAS identified 10 genome-wide significant loci including SCD and FADS with the SCD lead variant explaining ~7–11% of variance and ratios showing heritability up to ~54%. Functional implication: colocalizations with adipose-specific eQTLs and meQTLs and associations between metabolic polygenic scores and fatty acid levels link local genetic regulation in adipose tissue to renal and cardio-metabolic phenotypes.

Conclusion:
Local genetic variation in adipose tissue, including SCD, FADS and a 3p25.2 locus near PPARG, regulates fatty acid composition and conversion and is connected to renal and cardio-metabolic traits.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Genetic regulation of fatty acid content in adipose tissue

First author:
Yan X

Journal:
The American Journal of Human Genetics, Corrected proof. doi:10.1016/j.ajhg.2025.12.008

DOI:
10.1016/j.ajhg.2025.12.008

Reference:
Yan X., Roberts A.L., El-Sayed Moustafa J.S., Villicaña S., Al-Hilal M., Tomlinson M., Menni C., Sanders T.A.B., Freidin M.B., Bell J.T., Small K.S., Genetic regulation of fatty acid content in adipose tissue. The American Journal of Human Genetics 113, 1–18, February 5, 2026. https://doi.org/10.1016/j.ajhg.2025.12.008

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/scd-fads-pparg-adipose

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-02-04.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited substantive scientific claims regarding adipose fatty acid heritability and tissue specificity, GWAS loci (SCD, FADS, 3p25.2/PPARG), adipose molecular mechanisms (eQTL/meQTL colocalization), the fat–kidney link via pleiotropy, and polygenic-score associations with adipose fatty acids; also covered study limitat
- transcript topics: Adipose fatty acid heritability and tissue specificity; Genome-wide association signals for adipose fatty acids (SCD, FADS, 3p25.2/PPARG); Adipose-specific regulation and colocalization with eQTL/meQTL; Arachidonic acid and kidney trait pleiotropy; Polygenic scores and adipose fatty acids; Limitations and demographic scope

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Adipose fatty acids show heritability with tissue specificity; adipose heritability ranges widely (0–59%), with some fatty acids showing little to no heritability in adipose but hi
- GWAS identified 10 independent loci associated with adipose fatty acids and ratios; SCD and FADS loci were replicated, and a novel 3p25.2 locus near PPARG/MKRN2/TSEN2 was identifie
- SCD locus exhibits adipose-specific regulatory effects (adipose eQTL and meQTL colocalization; adipose SCD expression correlates with fatty acid ratios).
- 3p25.2 locus regulates arachidonic acid and the arachidonic acid/linoleic acid ratio in adipose tissue and colocalizes with kidney-trait signals (eGFR, creatinine, cystatin C), ind
- GWAS signals at SCD, FADS, and 3p25.2 show molecular-trait colocalization with eQTLs/meQTLs, supporting tissue-specific regulatory mechanisms.
- Polygenic scores for BMI, fat distribution, and triglycerides are associated with adipose tissue fatty acid levels, linking systemic metabolic risk to local adipose composition.

QC result: Pass.

279: Against the Uncritical Adoption of AI in Universities: LLMs, Chatbots, and Academic Integrity (Guest et al.)

Gustavo Barra — Mon, 02 Feb 2026 22:23:34 +0000

Guest O et al. - Position piece urging universities to resist uncritical adoption of AI technologies such as LLMs and chatbots because they undermine academic freedom, integrity, and pedagogical skills. Key terms: artificial intelligence, higher education, large language models, academic freedom, critical AI literacy.

Study Highlights:
System: the higher education sector and university classrooms; methods: a co-authored open letter, conceptual analysis, and literature synthesis drawing on historical and contemporary sources. The authors analyse how AI industry marketing, ambiguous jargon, closed-source models, and extractive data and labour practices create institutional dependencies and conflicts of interest. They show this structural entanglement erodes research integrity, deskills students and staff, and produces environmental and social harms. As a functional implication they call for principled refusal, transparency, critical AI literacy, and policy measures to protect academic freedom and the ecosystem of human knowledge.

Conclusion:
Universities must reject the uncritical adoption of AI technologies and take active measures to safeguard critical thinking, expertise, academic freedom, and scientific integrity.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Against the Uncritical Adoption of AI Technologies in Academia

First author:
Guest O

Journal:
Zenodo

DOI:
10.5281/zenodo.17065099

Reference:
Guest O, Suarez M, Muller BCN, van Meerkerk E, Oude Groote Beverborg A, de Haan R, et al. Against the Uncritical Adoption of AI Technologies in Academia. Zenodo. 2025. https://doi.org/10.5281/zenodo.17065099

License:
This episode is based on an open-access preprint released under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/universities-resist-ai-adoption

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-02-02.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited transcript sections that discuss the preprint 'Against the Uncritical Adoption of AI Technologies in Academia' and its critiques: hype/terminology, environmental and labor harms, two victims of plagiarism, knowledge production vs knowledge translation, and guardrails for AI-assisted science communication.
- transcript topics: AI hype and terminology in academia; Marketing, hype, and harm of AI technologies; Environmental costs and ghost labor in AI; Two victims of plagiarism (original author and audience); Knowledge production vs knowledge translation; Guardrails for ethical AI use in science communication

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- AI hype and marketing as a concern in academia
- Environmental costs and labor (ghost work) associated with AI systems
- The concept of two victims of plagiarism (original author and audience)
- Distinction between knowledge production and knowledge translation
- Need for guardrails and human verification in AI-assisted science communication
- Call for critical AI literacy and public discussion

QC result: Pass.

278: Illumina, Grail and FTC scrutiny of vertical mergers in human genetic technologies

Gustavo Barra — Mon, 02 Feb 2026 05:47:51 +0000

Rashid AI et al., The American Journal of Human Genetics, Corrected proof. doi:10.1016/j.ajhg.2025.12.012 - US antitrust shifts in human genetic technologies: FTC scrutiny of Illumina’s acquisition of Grail alters NGS market oversight and could affect spin-offs and startups. Key terms: Illumina, Grail, vertical mergers, FTC merger guidelines, non-compete rule.

Study Highlights:
This perspective examines the US legal and regulatory landscape for human genetic and genomic technologies, focusing on FTC and DOJ policy changes and enforcement habits. Using a case-study approach centered on Illumina’s proposed acquisition and eventual divestiture of Grail, the authors review updated merger guidelines, non-compete rule developments, and exclusive-dealing concerns. They report that the 2023 merger guidelines lowered thresholds for presumed anti-competitiveness and that the FTC’s challenge emphasized risks to nascent mult-cancer early detection competitors that rely on next-generation sequencing platforms. The authors conclude that heightened vertical-merger scrutiny may reduce spin-offs and early-stage acquisitions, prompting firms to favor in-house R&D or alternate collaboration models.

Conclusion:
Heightened scrutiny of vertical mergers and attention to nascent competition in US antitrust policy is likely to reshape biotechnology strategies by reducing spin-offs and encouraging in-house development.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Competition in human genetic technologies: The current US legal landscape

First author:
Rashid AI

Journal:
The American Journal of Human Genetics, Corrected proof. doi:10.1016/j.ajhg.2025.12.012

DOI:
10.1016/j.ajhg.2025.12.012

Reference:
Rashid AI, Rincon NA, Rihani N, Wagner JK. Competition in human genetic technologies: The current US legal landscape. The American Journal of Human Genetics. 2026;113:1–10. https://doi.org/10.1016/j.ajhg.2025.12.012

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/illumina-grail-vertical-mergers

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-02-02.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript sections that discuss antitrust policy landscape, the Illumina/Grail vertical merger case, regulatory instruments (HSR, Sherman, Clayton), NASCENT competition, spin-offs and IRS spin-off rules, non-compete status, and startup financing implications.
- transcript topics: Illumina/Grail vertical merger case; Foreclosure theory in vertical mergers; Open offer and divestiture outcome; 2023 merger guidelines and vertical mergers; Nascent competition and spin-offs; IRS rules on corporate spin-offs

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Illumina/Grail case as a vertical merger example with divestiture
- Foreclosure as a potential anti-competitive mechanism in vertical mergers
- 2023 merger guidelines lowered thresholds for presumed anti-competitiveness
- IRS spin-off rules tightened in January 2025 with stricter proof and reporting
- Non-compete regulation status: initial nationwide ban with subsequent rulings and continued case-by-case enforcement
- Startup financing pressures (kill zone) due to antitrust scrutiny and exit constraints

QC result: Pass.

277: MDGA2 homozygous loss-of-function variants in developmental and epileptic encephalopathy

Gustavo Barra — Sun, 01 Feb 2026 21:49:52 +0000

Morsy H et al., The American Journal of Human Genetics, Corrected proof. doi:10.1016/j.ajhg.2025.12.015 - Exome sequencing identifies homozygous MDGA2 loss-of-function variants in nine individuals and functional neuronal assays show impaired MDGA2 trafficking with disrupted Nlgn1-dependent excitatory synapse regulation causing DEE. Key terms: MDGA2, developmental and epileptic encephalopathy, loss-of-function, neuroligin-1, exome sequencing.

Study Highlights:
Exome sequencing of consanguineous families identified seven distinct homozygous MDGA2 loss-of-function variants in nine individuals with severe developmental and epileptic encephalopathy. Functional evaluation used mammalian expression in HEK293T cells, heterologous synapse-formation assays, cultured hippocampal neurons, and electrophysiology. Representative nonsense variants abolished MDGA2 surface trafficking, disrupted MDGA2–Nlgn1 binding, failed to suppress excitatory synapse density, and did not reduce AMPAR- and NMDAR-mediated synaptic responses. These synaptic deficits imply disruption of excitatory-inhibitory balance, providing a mechanistic link to early-onset intractable seizures and progressive neurodevelopmental impairment.

Conclusion:
Homozygous MDGA2 loss-of-function variants cause an autosomal-recessive developmental and epileptic encephalopathy by impairing MDGA2 trafficking and Nlgn1-dependent suppression of excitatory synapses.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
MDGA2 homozygous loss-of-function variants cause developmental and epileptic encephalopathy

First author:
Morsy H

Journal:
The American Journal of Human Genetics, Corrected proof. doi:10.1016/j.ajhg.2025.12.015

DOI:
10.1016/j.ajhg.2025.12.015

Reference:
Morsy H, Kim H, Jang G, et al. MDGA2 homozygous loss-of-function variants cause developmental and epileptic encephalopathy. The American Journal of Human Genetics. 2026;113:1–12. https://doi.org/10.1016/j.ajhg.2025.12.015

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/mdga2-loss-of-function-dee

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-02-01.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audit covered the sections describing MDGA2 function in synaptic regulation, genetic basis (LoF variants in consanguineous families), functional assays (trafficking, Nlgn1 interactions, synapse formation, electrophysiology), clinical phenotype (DEE with seizures), and therapeutic angles (ketogenic diet, potential recep
- transcript topics: MDGA2 as a brake on Nlgn1 and suppression of excitatory synapses; Genetic basis: homozygous loss-of-function MDGA2 variants in consanguineous families; Functional validation: trafficking and surface expression of MDGA2; Nlgn1 interaction; Synapse formation and electrophysiology: mEPSCs, AMPAR/NMDAR EPSCs; Clinical presentation: DEE phenotype, hypotonia, seizures, dysmorphic features, MRI findings; Therapeutic angles: ketogenic diet effects; potential TRKB/AMPA receptor–related targets

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- MDGA2 homozygous loss-of-function variants identified in nine individuals from seven consanguineous families
- MDGA2 variants cause trafficking impairment and loss of surface expression with disrupted Nlgn1 interaction
- MDGA2 waives suppression of excitatory synapses in LoF variants; WT MDGA2 suppresses excitatory synapse numbers
- Electrophysiology shows MDGA2 WT reduces mEPSC frequency and AMPAR/NMDAR EPSCs; LoF variants fail to alter synaptic function
- DEE phenotype with early-onset seizures, severe developmental delay, dysmorphic features; brain MRI shows delayed myelination and early brain atrophy
- Ketogenic diet produced partial seizure control in two individuals (P4 and P5B)

QC result: Pass.

276: AlphaGenome: 1-Mb multimodal deep model predicts regulatory variant effects including splicing and TAL1 mechanisms

Gustavo Barra — Fri, 30 Jan 2026 22:00:21 +0000

Avsec et al., Nature, doi:10.1038/s41586-025-10014-0 - AlphaGenome, a 1 Mb DNA deep‑learning model, predicts base‑pair‑resolution genome tracks (RNA‑seq, splicing, chromatin) and scores variant effects, achieving state‑of‑the‑art performance across modalities. Key terms: AlphaGenome, splicing, eQTL, chromatin-accessibility, 1Mb-sequence.

Study Highlights:
AlphaGenome is a unified sequence‑to‑function deep learning model trained on human and mouse genomes that consumes 1 Mb of DNA and predicts 5,930 human genome tracks across 11 modalities using a U‑Net‑inspired encoder, transformer tower and decoder. The model was pretrained with fold splits and distilled into a single student model for efficient variant scoring, enabling base‑pair resolution outputs and splice junction prediction alongside splice site usage and RNA‑seq coverage. Quantitatively, AlphaGenome outperformed or matched external models on 22 of 24 genome track tasks and on 25 of 26 variant effect benchmarks, improving eQTL sign prediction and QTL effect correlations. The multimodal outputs enable mechanistic interpretation of variants, for example recapitulating oncogenic TAL1 enhancer mutations and identifying splice‑disrupting variants.

Conclusion:
AlphaGenome provides a unified 1‑Mb multimodal, base‑resolution sequence model that substantially improves genome track and regulatory variant effect prediction and enables mechanistic, cross‑modality interpretation.

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-01-30.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript portions presenting AlphaGenome architecture, multimodal outputs, benchmarking, splicing, TAL1 mechanism, 3D genome, in silico mutagenesis, and limitations.
- transcript topics: AlphaGenome architecture (1 Mb input, U‑Net backbone, transformers, sequence parallelism); Multimodal genome tracks (5,930 human tracks, 1,128 mouse tracks across 11 modalities); Variant effect benchmarking (26 tasks; 25/26 ahead); Splicing variant predictions (splice sites, splice junctions, usage); TAL1 oncogene mechanism (neo-enhancer, MYB motif); 3D genome contact maps predictions

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- AlphaGenome takes input of 1 Mb DNA and predicts thousands of genome tracks across 11 modalities at base-pair resolution
- 5,930 human genome tracks and 1,128 mouse genome tracks predicted
- AlphaGenome matched or outperformed strongest external models on 25 of 26 variant-effect benchmarks
- Splicing variant predictions include splice sites, splice junctions, and splice site usage
- TAL1 oncogene mechanism recapitulated via a neo-enhancer and MYB motif
- 3D genome folding predicted via contact maps with improved performance over specialized tools

QC result: Pass.

275: MIPseq/WES of 11,555 CHD probands implicates 60 dominant genes with NOTCH1 cysteine‑altering and transmitted MYH6 missense variants

Gustavo Barra — Fri, 30 Jan 2026 19:36:34 +0000

Sierant MC et al., Proc. Natl. Acad. Sci. U.S.A. 2025.122:e2420343122 - MIPseq and exome sequencing of 11,555 human congenital heart disease probands implicate 60 dominant CHD genes, with NOTCH1 cysteine‑altering and transmitted MYH6 missense variants driving distinct defects. Key terms: congenital heart disease, NOTCH1, MYH6, MIPseq, de novo mutations.

Study Highlights:
We analyzed 11,555 human CHD probands from PCGC and PHN using a 248‑gene MIPseq panel and whole‑exome sequencing. A meta‑analysis of de novo and very rare transmitted/unphased damaging variants identified 60 genes with significant burden, accounting for damaging variants in 10.1% of probands with similar DNM and transmitted contributions. Mechanistically, NOTCH1 missense mutations that introduce or remove cysteines in EGF domains were highly enriched in tetralogy of Fallot and conotruncal defects, while transmitted damaging MYH6 missense variants were overtransmitted and contributed to multiple CHD subtypes. Genes with cardiomyocyte‑restricted expression correlated with isolated CHD, whereas broadly brain‑expressed genes correlated with neurodevelopmental delay, supporting genotype‑informed risk assessment.

Conclusion:
Targeted genomic analysis of 11,555 CHD probands identifies 60 dominant genes accounting for 10.1% of cases and supports molecular diagnosis to stratify cardiac and neurodevelopmental risk.

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-01-30.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript sections describing the study design (MIPseq), cohort composition, main genetic findings (60 genes, 10.1%), NOTCH1 cysteine-altering variants, MYH6 transmission findings, chromatin gene involvement, syndromic diagnoses, and cost reductions and future gene discovery projections.
- transcript topics: MIPseq methodology and cost reduction; Cohort assembly and the 248-gene panel; 60 significant CHD genes and 10.1% probands; NOTCH1 cysteine-altering variants in TOF/CTD (EGF domains, domain #5); MYH6 transmitted damaging variants and penetrance; Chromatin modifier genes and neurodevelopmental/EC phenotypes

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Study analyzed 11,555 CHD probands with a 248-gene MIPseq panel.
- 60 genes identified with significant burden of damaging variants; 10.1% of probands affected.
- Equal contributions from de novo and transmitted variants to CHD risk within the 60-gene set.
- NOTCH1 missense variants introducing/removing cysteines in EGF domains are enriched in TOF and CTD; cysteine-altering variants cluster in EGF domain #5.
- Transmitted damaging MYH6 missense variants enriched across multiple CHD phenotypes; risk ratio ~6; 2–3% of probands; ~1% of all trios.
- MYH6 is heart-restricted in expression; NDD risk among MYH6 carriers is low (~4%).

QC result: Pass.

Chapters

(00:00:20) - Deadly heart defect: The genetics of congenital heart disease
(00:03:05) - How 60 genes explain the cause of heart defect
(00:07:03) - Heart defects and neurodevelopmental delay
(00:10:24) - These are the hidden syndromes
(00:14:21) - Dazzling Sound

274: RPE MCT2: A metabolic gene-agnostic approach to preserve cones in RP

Gustavo Barra — Thu, 29 Jan 2026 06:02:37 +0000

PNAS - RPE-specific MCT2 gene delivery preserves cones and vision in retinitis pigmentosa models

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
RPE-specific MCT2 expression promotes cone survival in models of retinitis pigmentosa

Journal:
PNAS

DOI:
10.1073/pnas.2421978122

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-01-29.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited transcript sections covering: metabolic mechanism (RPE lactate uptake via MCT2 and glucose sparing), vector design (AAV8.Best1.MCT2), RP animal models and cone survival/function outcomes, FLIM-based lactate/glucose sensors (LiLac, GlucoSnFR-TS), MCT2 localization to apical/basal RPE membranes, observed species-
- transcript topics: RPE-specific MCT2 metabolic reprogramming; Retina metabolism: lactate, glucose, and NAD+ dynamics in RP; AAV8.Best1.MCT2 vector design and RPE specificity; RP models: S334ter rat, FVB mouse, P23H mouse; Cone survival and functional outcomes (cone counts and optomotor assay); FLIM-based lactate and glucose sensors (LiLac, GlucoSnFR-TS)

QC Summary:
- factual score: 10/10
- metadata score: 8/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 3
- metadata issues found: 1

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- RPE-specific MCT2 expression increases cone survival across RP models (rat S334ter; mouse FVB and P23H).
- MCT2 expression transiently preserves cone function in P23H mice (optomotor results at P40; diminished by P53).
- MCT2 localizes to apical and basal membranes of the RPE after AAV delivery.
- FLIM sensors show higher intracellular lactate and greater glucose accumulation in MCT2-expressing RPE, consistent with reduced glycolysis and glucose sparing for cones.
- Three RP mutations/models tested support a gene-agnostic approach.
- Toxicity observed in mice but not rats; potential translational bottleneck due to species-specific responses.

QC Flagged Items (audited and not fully supported):
- license: metadata does not match the canonical article record. License naming differs between metadata snapshot and article description; both refer to CC BY variants.
Internal QC note: manual editorial review is recommended before publication.

QC result: Warning. Items above were flagged during automated QC; the editorial team reviewed them before release.

Chapters

(00:00:00) - Blending Genomics Into Your Life
(00:00:28) - The starvation of RPE
(00:02:48) - New science in retinal degeneration
(00:03:56) - Gene therapy to save the retina
(00:08:04) - Pigmented eyes to help sight?
(00:10:25) - Genetics fixes blindness in mice
(00:13:47) - A New way to save the brain
(00:14:36) - Open the Gate, Let the Sugar Run

273: CTVT-A acquires 15-Mb N-HT1 dicentric nuclear element via horizontal transfer

Gustavo Barra — Wed, 28 Jan 2026 06:26:55 +0000

Gori K et al., Proc. Natl. Acad. Sci. U.S.A. 2025.122:e2424634122 - In canine transmissible venereal tumor (CTVT), deep sequencing and cytogenetics identify a 15‑Mb horizontally transferred nuclear element (N-HT1) acquired ~2,000 years ago that is transcriptionally active. Key terms: CTVT, horizontal gene transfer, N-HT1, PacBio long-read sequencing, centromeric fusion.

Study Highlights:
The authors screened 174 transmissible tumor genomes, focusing on CTVT, DFT1, and DFT2, using deep short-read sequencing, long-read PacBio sequencing, structural variant analysis, and metaphase FISH. In CTVT-A they discovered a 15-Mb dicentric element (N-HT1) assembled from 11 fragments of six chromosomes that forms the short arm of a small submetacentric chromosome after centromeric fusion. Mutation density and CpG-based dating place N-HT1 acquisition about 2,000 years ago, and transcriptome allele deconvolution shows N-HT1 is transcriptionally active and adopts the CTVT expression profile. Functional interrogation found no clear oncogenic drivers on N-HT1, with at least one rescued gene (ARFGEF3) later inactivated, consistent with the element behaving as a likely neutral passenger.

Conclusion:
A single host-to-tumor nuclear horizontal transfer event was detected in sampled transmissible cancers: CTVT-A acquired a 15-Mb N-HT1 element that is transcriptionally active but shows no clear evidence of positive selection.

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-01-28.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the core scientific claims presented about N-HT1: its structure, origin, timing, transcriptional activity, and evolutionary implications, as described in the article.
- transcript topics: CTVT background and transmissible cancers; SNP flipping screen to detect host-to-tumor nuclear transfer; Discovery and structure of N-HT1 (15 Mb, 11 fragments, from 6 chromosomes); Cytogenetics and centromeric fusion of N-HT1 onto a CTVT chromosome; Timing: acquisition ~2000 years ago and donor ancestry; Gene expression and functional impact (ARFGEF3 rescue)

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- N-HT1 is a 15-Mb horizontally transferred nuclear DNA element composed of 11 fragments from six canine chromosomes
- N-HT1 forms the short arm of a small submetacentric chromosome via centromeric fusion onto a CTVT chromosome
- N-HT1 was acquired by CTVT-A approximately 2,000 years ago
- N-HT1 is transcriptionally active and adopts the CTVT expression profile
- There is no clear evidence of positive selection acting on N-HT1 within CTVT-A
- ARFGEF3 was rescued from a null state by N-HT1 but was subsequently inactivated again

QC result: Pass.

Chapters

(00:00:00) - Blast by Bass
(00:00:29) - Cancer Has Stealing DNA From Your Body
(00:02:41) - Horizontal Transfer of nuclear DNA in transmissible cancer
(00:07:24) - The ghost of a dog's genome
(00:11:55) - Transmissible DNA in human cancer
(00:14:08) - Step, Step, Close Hold

272: ADSL A429V reduces purine biosynthesis in brain and alters female mouse water-seeking behavior

Gustavo Barra — Tue, 27 Jan 2026 05:22:26 +0000

Ju X-C et al., Proc. Natl. Acad. Sci. U.S.A. 2025.122:e2508540122 - Human-specific ADSL A429V substitution and a common regulatory haplotype reduce ADSL activity and raise purine substrates in the brain, altering mouse behavior. Key terms: adenylosuccinate lyase, A429V, purine biosynthesis, succinyladenosine, human evolution.

Study Highlights:
Model: mice humanized for ADSL carrying the modern-human A429V (with R428Q) were compared to wild-type littermates using ultraperformance LC–Orbitrap metabolomics and automated IntelliCage behavioral assays. Mechanistic/quantitative result: SAICAr and S-Ado concentrations increased up to ~2-fold in liver and 1.8–5.4-fold across cerebrum regions, and these increases correlated negatively with Adsl mRNA expression across tissues. Human genetics: a 7.8-kb haplotype (including rs8135371) at >97% carrier frequency is associated with lower ADSL expression, higher S-Ado in cerebrospinal fluid, and signals of positive selection. Functional implication: female humanized mice accessed water more efficiently under restricted conditions, linking reduced ADSL activity to altered behavior.

Conclusion:
Two genetic changes on the modern human lineage—a nearly fixed A429V amino acid substitution and a common regulatory haplotype—have reduced ADSL activity and expression, increasing purine substrates particularly in the brain and producing measurable behavioral effects in mice.

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-01-27.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited transcript sections describing the ADSL enzyme, the A429V substitution, mouse model (humanized Adsl), tissue metabolite changes, the IntelliCage water-competition experiment with female-specific effects, regulatory haplotype and selection signals, and human CSF/metabolite correlations with intelligence.
- transcript topics: ADSL role in purine biosynthesis; A429V modern-human substitution and enzyme stability; CRISPR-based humanized Adsl mouse model; Tissue-specific metabolic substrates SAICAr and S-Ado; Brain- and liver-specific accumulation patterns; IntelliCage water-competition behavioral assay and female-specific effects

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- The modern-human ADSL coding change (A429V) reduces enzyme stability and activity relative to Neanderthal version.
- A second regulatory haplotype reduces ADSL expression, especially in brain, with evidence of positive selection.
- In humanized Adsl mice, SAICAr and S-Ado accumulate, particularly in brain and liver; brain shows greatest impact due to low baseline Adsl expression.
- Female humanized mice show increased water-approach behavior under restricted water conditions; males show no difference.
- CSF levels of S-Ado correlate negatively with intelligence in humans (rg ≈ -0.13; small effect size but statistically significant).
- Positive selection signals are present for both the coding and regulatory changes, with estimated selection coefficients around 0.0016–0.0018.

QC result: Pass.

271: Rising EA PGI prediction of educational attainment across 1946–1970 British birth cohorts and socioeconomic interaction

Gustavo Barra — Sun, 25 Jan 2026 23:41:30 +0000

Morris TT et al., Proc. Natl. Acad. Sci. U.S.A. 2026.123:e2516460123 - EA and cognition polygenic indexes (PGIs) in three British birth cohorts show EA PGI associations with years of education increased from 1946–1970 and were strongest in advantaged socioeconomic backgrounds. Key terms: educational attainment, polygenic index, gene-environment interaction, British birth cohorts, socioeconomic status.

Study Highlights:
Using three nationally representative British birth cohorts born 1946, 1958, and 1970, the authors analyzed polygenic indexes for educational attainment (EA) and cognition. They generated PGIs with clumping-and-thresholding (PRSice2) and LDpred2, used multiple imputation and inverse probability weighting, and estimated linear models including cohort-by-PGI interactions. EA PGI associations increased from approximately 0.44 to 0.67 years of education per 1-SD and incremental R2 rose from 3.5% to 5.1% across cohorts, while cognition PGI associations were broadly stable. There was strong evidence of gene–environment interaction: returns to EA genetic liability were disproportionately larger among those born into more advantaged socioeconomic backgrounds.

Conclusion:
Across three British birth cohorts born 1946–1970, genetic liability indexed by an EA PGI became more predictive of years of completed education while cognition PGI prediction remained stable, and EA PGI effects were amplified in advantaged socioeconomic contexts.

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-01-25.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the core scientific claims conveyed in the transcript: temporal increase of EA PGI associations, stability of cognition PGI, GxE interaction by SES, non-cognitive vs cognitive PGI interpretation, and study limitations.
- transcript topics: EA PGI prediction of education across cohorts; Cognition PGI stability across cohorts; Polygenic indices (EA PGI and cognition PGI) methods; Gene–environment interactions with socioeconomic background; Non-cognitive vs cognitive PGI interpretation; Limitations: ancestry and PGI portability

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 5
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- EA PGI associations with years of completed education increased across cohorts (1946c 0.44, 1958c 0.49, 1970c 0.67).
- Cognition PGI associations with education remained broadly stable across cohorts (1946c 0.23, 1958c 0.27, 1970c 0.24).
- EA PGI explained incremental variance in education rising from 3.5% to 5.1% across cohorts.
- Gene–environment interaction: higher returns to EA PGI among advantaged backgrounds and near-null returns among the most disadvantaged.
- Non-cognitive PGI captures additional variance; cognition PGI did not show increasing predictive power.
- Limitations include ancestry limitation to white European participants and PGI portability concerns.

QC result: Pass.

Chapters

(00:00:00) - Genetics and the socioeconomic gap
(00:04:36) - The genetic link between school and success
(00:07:42) - Genetics and educational success
(00:11:42) - The Wealthy Kids and the Poor
(00:12:56) - The genetics of intelligence and personality
(00:15:38) - Open Access: Science Podcast
(00:16:31) - Inheritance

270: Human Topoisomerase IIIα–RMI1–RMI2 (TRR) processively relaxes negatively supercoiled DNA measured by optical tweezers

Gustavo Barra — Sun, 25 Jan 2026 23:03:54 +0000

Spakmana D et al., Proc. Natl. Acad. Sci. U.S.A. 2026.123:e2406949123 - Optical tweezers and fluorescence imaging show human Topoisomerase IIIα–RMI1–RMI2 (TRR) processively relaxes highly negatively supercoiled DNA faster than PICH loops. Key terms: topoisomerase IIIα, TRR complex, DNA supercoiling, optical tweezers, ultrafine anaphase bridges.

Study Highlights:
Using torsionally constrained end-closed λ-DNA in a multichannel flow cell, the authors combined Optical DNA Supercoiling (ODS), dual-trap optical tweezers, and fluorescence imaging to measure supercoiling density and visualize TRR binding in real time. They find TRR relaxes hyper-negatively supercoiled DNA in a highly processive manner, with single TRR complexes performing thousands (>3,000) of strand-passage reactions and exhibiting a force-dependent rate described by an Arrhenius relation (δ ≈ 1.1–1.4 nm in ensemble and single-molecule fits). Ensemble TRR activity was ~10-fold lower than E. coli TopoI under the same conditions, while single- complex rates indicate a single TRR can relax PICH-generated negative loops within the reported loop lifetime. These results support a mechanistic role for TRR in relaxing PICH-generated negative supercoils that could facilitate ultrafine anaphase bridge resolution.

Conclusion:
Human topoisomerase IIIα–RMI1–RMI2 (TRR) relaxes highly negatively supercoiled DNA in a force-dependent, highly processive manner and can act within the lifetime of PICH-generated negative loops, supporting a role in ultrafine anaphase bridge resolution.

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-01-25.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Substantive auditing of the transcript's presentation of TRR mechanism, speed and processivity, binding preferences, dwell times, single-molecule assay setup, relation to PICH loop dynamics, and implications for ultrafine anaphase bridge resolution.
- transcript topics: TRR mechanistic relaxation of negatively supercoiled DNA; Single-molecule optical DNA supercoiling (ODS) assay with dual-trap optical tweezers; TRR processivity and burst dynamics; Force dependence and Arrhenius behavior (δ values); AT-rich sequence binding preferences of TRR; PICH loop dynamics and ultrafine bridge context

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- TRR relaxes hyper-negatively supercoiled DNA in a highly processive manner
- A single TRR complex can catalyze thousands of strand passages (>3,000 Lk) without dissociating
- Ensemble relaxation rate ~35 Lk/s; TRR is ~10-fold slower than EcTopoI; δ ~ 1.1 nm
- Single TRRmCherry complexes exhibit force-dependent relaxation with δ ~ 1.4 nm
- TRR binds preferentially to AT-rich sequences and melted bubbles
- TRR remains bound to DNA for tens of minutes after relaxation

QC result: Pass.

Chapters

(00:00:00) - The Great Divide: When will the bridge break?
(00:02:41) - Deep Dive: The mechanism of DNA supercoils by human to
(00:03:49) - The Hidden Story of DNA
(00:08:02) - How fast does TRR work on DNA?
(00:12:40) - Why TRR Stuck to the DNA
(00:17:30) - Who is the bouncer of DNA?

269: Mlh1–Pms1 endonuclease creates single-strand gaps to excise mispairs in S. cerevisiae MMR

Gustavo Barra — Sat, 24 Jan 2026 06:01:33 +0000

Palacio T et al., Proc. Natl. Acad. Sci. U.S.A. 2025.122:e2528670122 - Reconstituted Saccharomyces cerevisiae mismatch repair shows the Mlh1–Pms1 endonuclease directly generates single-strand gaps to excise mispairs independent of Exo1 and Rad27. Key terms: Mlh1-Pms1, mismatch repair, single-strand gaps, Exo1, APOBEC3A.

Study Highlights:
We reconstituted Saccharomyces cerevisiae mismatch repair with purified Msh2–Msh6 or Msh2–Msh3, Mlh1–Pms1, PCNA, RFC, RPA, and DNA polymerases and analyzed products by restriction mapping, Mung Bean nuclease, electron microscopy, and APOBEC3A deamination. The Mlh1–Pms1 endonuclease, activated by RFC-loaded PCNA and Mn2+, generates strand-specific single-strand gaps on the preexisting nicked strand. Electron microscopy and deamination mapping revealed a broad distribution of gap sizes with a peak around 128 ± 17 nucleotides and most gaps under 500 nucleotides. These gaps can be filled by DNA Polε or low levels of DNA Polδ, providing an Exo1- and Rad27-independent route for mispair excision and explaining redundancy among excision pathways.

Conclusion:
Mlh1–Pms1 catalyzes strand-specific single-strand gap formation that mediates Exo1- and Rad27-independent mispair excision in reconstituted S. cerevisiae mismatch repair.

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-01-24.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited sections: Exo1/Rad27 independence, MLH1-Pms1 endonuclease role, Mn2+ activation, gap formation and sizes, EM evidence, APOBEC3A gap mapping, and the proposed three-pathway MMR model.
- transcript topics: Background on mismatch repair and Exo1/Rad27 roles; Exo1- and Rad27-independent MMR reconstitution; MLH1-Pms1 endonuclease activity and Mn2+ activation; Formation and types of single-stranded gaps; Electron microscopy evidence of gap sizes; APOBEC3A mapping of excision gaps

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Combined Exo1- and Rad27-independent repair accounts for a small fraction (5–13%) of MMR when Exo1/Rad27 pathways are deleted, with Exo1/Rad27 contributing the remainder via redund
- MLH1–Pms1 endonuclease can drive mispair excision independently of Exo1 and Rad27.
- MLH1–Pms1–mediated repair generates strand-specific single-stranded gaps on the nicked strand.
- Gap sizes are broadly distributed with a peak at 128 ± 17 nucleotides; most gaps are under 500 nucleotides.
- Gaps can be filled by DNA Polε or low levels of DNA Polδ, enabling Exo1- and Rad27-independent repair.
- Mn2+ activates MLH1–Pms1 endonuclease; Mg2+ alone does not support robust activity.

QC result: Pass.

Chapters

(00:00:00) - Base by Bass
(00:00:29) - Who is the real repairman of DNA?
(00:02:39) - The spell-checker for our DNA
(00:04:23) - The ghost mechanic of DNA repair
(00:07:02) - The secret to DNA repair
(00:09:48) - How DNA repair works: The 3 pathways
(00:13:43) - How to Stop cancer with a single drug

268: M493I in human β-cardiac myosin: SRX disruption, slow ADP release, and enhanced actin attachment

Gustavo Barra — Fri, 23 Jan 2026 06:17:26 +0000

Cail RC et al., Proc. Natl. Acad. Sci. U.S.A. 2025.122:e2521561122 - Recombinant human β-cardiac myosin M493I studied by optical trapping and stopped-flow kinetics disrupts the super-relaxed state and increases actin attachment and contractile force. Key terms: β-cardiac myosin, M493I, super-relaxed state, actin attachment, optical trap.

Study Highlights:
System: recombinant human β-cardiac heavy meromyosin (cHMM) expressed in C2C12 cells. Methods: ensemble actin gliding, stopped-flow kinetics, NADH ATPase, mantATP single-turnover, and single-molecule three-bead optical trap assays. Main results: M493I preserves Pi release and the two-step 4.7–5 nm working stroke but slows ADP release ~5-fold, doubles steady-state ATPase Vmax, reduces SRX occupancy (KSRX/DRX from ~0.33 to ~0.53), and prolongs actin attachment with increased high-force, long-duration interactions. Functional implication: the combined increase in DRX head availability and prolonged AM·ADP lifetimes produce higher sustained force and faster actin reattachment consistent with a mechanism for HCM hypercontractility and impaired relaxation.

Conclusion:
The M493I relay-helix mutation disrupts the SRX off state and, together with slowed ADP release and prolonged actin attachment, increases myosin head availability and force production, explaining its hypercontractile HCM phenotype.

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-01-23.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited transcript sections covering the M493I mutation in the relay helix, SRX/DRX equilibrium and head availability, ADP release kinetics and duty ratio, actin gliding and power stroke, isometric high-force attachments, single-molecule actin reattachment dynamics, and mavacamten/therapeutic implications.
- transcript topics: M493I mutation in relay helix and mechanistic role; SRX/DRX equilibrium and head availability; ADP release kinetics and duty ratio; Actin gliding velocity and power stroke; Isometric high-force attachments under hindering load; Single-molecule actin reattachment dynamics

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- M493I slows ADP release ~5-fold (ADP release ~12 s−1 vs ~69 s−1 for WT).
- Actin gliding velocity reduced ~70% (WT ~1.6 μm/s; M493I ~0.46 μm/s).
- SRX/DRX disruption: SRX/DRX equilibrium constant ~0.53 (M493I) vs ~0.33 (WT); DRX heads ~35% vs ~25%.
- Duty ratio increases from ~0.017 (WT) to ~0.20 (M493I).
- Power output under hindering load (0–10 pN) nearly twofold higher for M493I vs WT.
- Single-molecule actin reattachment fastest component ~1.62 s−1 (M493I) vs ~0.83 s−1 (WT).

QC result: Pass.

Chapters

(00:00:00) - Heart Hypertrophic Cardiomyopathy: The genetic puzzle
(00:04:48) - Myosin motors: Do they Pull or Float?
(00:07:50) - Heart Disease: M493I mutant causes heart to slow
(00:12:16) - Heart dysrhythmias: The sticky insomniac motor
(00:17:54) - Hold on Hold On

267: DNA base-pair opening modes and soliton-like loops revealed by hydrogen exchange

Gustavo Barra — Thu, 22 Jan 2026 05:41:03 +0000

Englander SW et al., Proc. Natl. Acad. Sci. U.S.A. 2026.123:e2520855122 - Hydrogen exchange (H-T and NMR H-H) on DNA and RNA reveals two distinct base-pair opening modes: single-base microsecond openings and multi-base millisecond soliton-like loops. Key terms: hydrogen exchange, DNA dynamics, base pair opening, soliton, H-T exchange.

Study Highlights:
Systems studied include long polynucleotides (DNA, duplex RNA, synthetic long duplexes) and short oligonucleotides; key methods are H-T (tritium) exchange, stopped-flow H-D, and NMR H-H (water relaxation) measurements. H-T exchange of long polymers reports opening-limited EX1 imino exchange with kop ~1/s, reclosing kcl ~20/s and Kop ~10^-2 consistent with multi-base open loops with ms lifetimes. NMR H-H on short oligos reports catalyzable EX2 behavior dominated by single base-pair openings with kcl ~10^6/s and Kop ~10^-6 and microsecond lifetimes. The selective detection implies short oligonucleotides cannot host extensive loops while multi-base soliton-like loops in polynucleotides could dynamically expose sequences for protein or nucleic acid recognition.

Conclusion:
Both H-T and NMR H-H exchange provide accurate but complementary views: long polynucleotides exhibit frequent multi-base, ms-lived open loops (Kop ~10^-2, kcl ~20/s) while short oligonucleotides reveal rare single-base, μs-lived openings (Kop ~10^-6, kcl ~10^6/s).

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-01-22.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited transcript portions describing hydrogen exchange theory, EX1/EX2, the two base-pair opening modes, the soliton traveling loop hypothesis, length dependence, and biological implications as presented in the article.
- transcript topics: Hydrogen exchange theory and Eigen proton-transfer foundations; H-T exchange in long polynucleotides (1000+ bp) and EX1 vs EX2 interpretation; H-H exchange by NMR in short oligonucleotides and its constraints; Two base-pair opening modes: single-base openings (EX1-dominated) and multi-base open loops (EX2-dominated); Soliton traveling loop hypothesis and migration along DNA; Length dependence reconciles datasets (native long DNA vs short oligonucleotides)

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 5
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- There are two base-pair opening modes: single-base openings detected by NMR on short oligonucleotides and multi-base open loops observed in long polynucleotides
- HT (tritium) exchange reports ms-lived open loops with Kop ~ 10^-2 and kcl ~ 20 s^-1 in long polynucleotides, with open-state population Kop ~ 10^-2 (~1%)
- HH-NMR exchange on short oligonucleotides reports μs-lived single-base openings with Kop ~ 10^-6 and very low open-state population
- A traveling soliton-like loop mechanism is proposed to explain how open states migrate along DNA and expose sequences
- Length of nucleic acid dictates which HX method observes which opening mode, reconciling historical discrepancies
- Cryo-EM is proposed as a future method to visualize soliton-like waves and validate the hypothesis

QC result: Pass.

Chapters

(00:00:00) - Papercast: The mystery of DNA
(00:02:42) - Breaking down the mystery of DNA
(00:03:26) - How does DNA open? The '
(00:07:43) - DNA is Not Like Longer Strands
(00:11:32) - The physics of DNA replication
(00:16:10) - I'm 1% Open

266: TOP1α and TOP3β Differentially Regulate HPV31 Replication via R-loops and DNA Breaks

Gustavo Barra — Wed, 21 Jan 2026 06:47:30 +0000

Vatsa A et al., Proc. Natl. Acad. Sci. U.S.A. 2026.123:e2526296123 - In HPV31-positive keratinocytes (CIN612), TOP1α and TOP3β are upregulated and required for viral transcription and replication, acting via distinct effects on R-loop accumulation and topoisomerase-mediated DNA breaks. Key terms: HPV31, TOP1α, TOP3β, R-loops, DNA breaks.

Study Highlights:
Using HPV31-positive CIN612 cells and primary HFK controls, the authors applied ChIP, RADAR, DRIP, alkaline COMET, RNA-seq, and shRNA knockdown to map topoisomerase binding and function. They found TOP1α and TOP3β, but not TOP3α, are elevated in HPV-positive cells and bind the viral URR, and that shRNA depletion of TOP1α or TOP3β reduced episomal viral DNA and early viral transcripts. Knockdown decreased DNA breaks (~50% reduction in COMET tail formation and reduced γH2AX) and altered R-loop levels differentially, with TOP1α depletion increasing viral R-loops by ~50% and TOP3β depletion causing >3-fold R-loop accumulation at viral and cellular loci. Transcriptome changes included reduced IL6/STAT3-AKT signaling after TOP1α loss and marked downregulation of EGR3 (>5-fold) after TOP3β loss, linking distinct mechanistic effects to impaired viral replication.

Conclusion:
TOP1α and TOP3β are differentially required for maintenance of HPV episomes and viral gene expression through distinct regulation of DNA breaks, R-loop dynamics, and specific host signaling pathways.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Differential roles of type I topoisomerases in regulating HPV pathogenesis

First author:
Vatsa A

Journal:
Proc. Natl. Acad. Sci. U.S.A. 2026.123:e2526296123

DOI:
10.1073/pnas.2526296123

Reference:
Vatsa A, Templeton CW, Laimins L. Differential roles of type I topoisomerases in regulating HPV pathogenesis. Proc. Natl. Acad. Sci. U.S.A. 2026.123:e2526296123. https://doi.org/10.1073/pnas.2526296123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/top1alpha-top3beta-hpv-replication

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-01-21.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited sections covering HPV biology and torsional stress, TOP1α/TOP3β (and TOP3α) roles, URR binding and episomal maintenance, knockdown effects on viral DNA and transcription, R-loop dynamics (DRIP), DNA breaks (COMET, γH2AX, TOP1cc/TOP3cc), DDR involvement, and host signaling changes (IL-6/STAT3-AKT, EGR3).
- transcript topics: HPV-induced torsional stress and topoisomerase roles; TOP1α, TOP3β, and TOP3α expression in HPV-positive cells; Binding of TOP1α and TOP3β to the HPV URR and episomal maintenance; shRNA knockdown effects on HPV genome levels and viral transcription; R-loop dynamics and DRIP analyses; DNA damage and TOP1cc/TOP3cc formation; γH2AX and COMET results

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- TOP1α and TOP3β are elevated in HPV-positive cells and bound to the HPV genome URR, while TOP3α is not bound to URR and is not essential for replication/transcription.
- Knockdown of TOP1α or TOP3β reduces HPV episome DNA and early viral transcripts (E1, E2, E6, E7).
- TOP1α depletion increases viral R-loops; TOP3β depletion increases R-loops more dramatically (greater than 3-fold).
- TOP1α and TOP3β knockdown reduces DNA breaks (COMET tail moment ~50% reduction; γH2AX decreases).
- TOP1α and TOP3β depletion reduces TOP1cc/TOP3cc formation; R-loop recruitment factors (DHX9, POLR3H) are modulated accordingly.
- Expression of HPV oncoproteins E6 and E7 upregulates TOP1α and TOP3β.

QC result: Pass.

265: ANTSR lncRNA and the conserved multiallelic sex-determining locus across Aculeata

Gustavo Barra — Tue, 20 Jan 2026 05:51:41 +0000

Yu C et al., Proc. Natl. Acad. Sci. U.S.A. 2026.123:e2522417123 - Genetic mapping and comparative genomics show the lncRNA ANTSR multiallelic locus in Aculeata directs female development via heterozygosity despite lacking sequence homology. Key terms: ANTSR, Aculeata, lncRNA, complementary sex determination, heterozygosity.

Study Highlights:
The study analyzed 41 hymenopteran genomes and performed whole-genome resequencing and genetic mapping in Bombus terrestris and Vespa velutina nigrithorax to locate the sex-determining region. The ANTSR locus is a multiallelic noncoding interval between CRELD2 and THUMPD3 that is highly polymorphic and heterozygous in females but homozygous in diploid males across ants, bumblebees, and hornets. Comparative synteny shows the CRELD2–THUMPD3 block originated ~160–200 Mya and the locus has functioned as a zygosity-based female determinant for over 150 million years. Despite this deep functional conservation, alignments and phastCons analyses reveal no detectable sequence homology among distant aculeate lineages, and heterozygosity at ANTSR provides an actionable molecular sex marker for breeding and conservation.

Conclusion:
The ANTSR multiallelic noncoding locus is an ancient, positionally conserved zygosity-based sex determinant across Aculeata that has retained function for over 150 million years despite complete sequence divergence.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Deep evolutionary conservation of a sex-determining locus without sequence homology

First author:
Yu C

Journal:
Proc. Natl. Acad. Sci. U.S.A. 2026.123:e2522417123

DOI:
10.1073/pnas.2522417123

Reference:
Yu C, Moog S, Pan Q, Keller Valsecchi CI, Dupont S, Darrouzet E, Darras H, Hodapp D, Colgan TJ, et al. Deep evolutionary conservation of a sex-determining locus without sequence homology. Proc. Natl. Acad. Sci. U.S.A. 2026;123:e2522417123. https://doi.org/10.1073/pnas.2522417123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/antsr-aculeata-sex-locus

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-01-20.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Substantive audit of the transcript sections describing: (1) haplodiploid sex determination in Hymenoptera; (2) ANTSR locus and its position between CRELD2 and THUMPD3; (3) heterozygosity-dependent female development demonstrated in Bombus terrestris and Vespa velutina; (4) ANTSR as a long noncoding RNA; (5) absence of
- transcript topics: haplodiploid sex determination in Hymenoptera; ANTSR locus and CRELD2–THUMPD3 synteny; heterozygosity-based female determination at ANTSR; Bombus terrestris: lab crosses and diploid male production; Vespa velutina nigrithorax: field data and haplotype diversity; ANTSR as a long noncoding RNA

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- ANTSR locus is a multiallelic noncoding region that determines female development via heterozygosity.
- ANTSR locus is located between CRELD2 and THUMPD3; synteny preserved across Aculeata with origin ~160–200 Myr ago.
- In Bombus terrestris, crosses yield diploid males; females are heterozygous at the ANTSR locus and diploid males are homozygous at that region.
- In Vespa velutina nigrithorax, a 13.3 kb interval on chromosome 23 shows female–heterozygous/diploid male–homozygous patterns; four haplotypes observed in France.
- ANTSR encodes a long noncoding RNA; sequence conservation across Aculeata is not detectable.
- Honey bees lost the ANTSR system and use csd as the primary sex determiner.

QC result: Pass.

264: Single-TF rejuvenation: EZH2, E2F3, STAT3, ZFX identified by TRDP/Perturb-seq rejuvenate human fibroblasts and mouse liver

Gustavo Barra — Mon, 19 Jan 2026 06:11:15 +0000

Sengstack J et al., Proc. Natl. Acad. Sci. U.S.A. 2026.123:e2515183123 - TRDP with Perturb-seq in human fibroblasts found that manipulating TFs (EZH2, E2F3, STAT3, ZFX) reversed aging hallmarks, and EZH2 overexpression rejuvenated aged mouse livers. Key terms: EZH2, E2F3, Perturb-seq, liver rejuvenation, transcription factor.

Study Highlights:
The study used passaged human neonatal dermal fibroblasts and aged mouse liver as model systems and applied the Transcriptional Rejuvenation Discovery Platform (TRDP) with Perturb-seq and CRISPRa/CRISPRi screens. Overexpressing E2F3 or EZH2 and repressing STAT3 or ZFX reversed global gene expression toward earlier passage states and ameliorated cellular aging hallmarks including increased proliferation, proteasome activity, and mitochondrial function. In aged mice, AAV8-mediated liver-specific EZH2 overexpression (log2fc ≈ 2.9) reversed thousands of age-associated gene changes (R_rej = -0.42), reduced steatosis and fibrosis, and improved glucose tolerance. Downstream transcriptional programs converged across perturbations, suggesting shared molecular requirements for cellular and tissue rejuvenation.

Conclusion:
Single transcription factor perturbations identified by TRDP can reverse cellular aging hallmarks in human fibroblasts and, in the case of EZH2 overexpression, partially rejuvenate aged mouse liver with improved histology and glucose tolerance.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Systematic identification of single transcription factor perturbations that drive cellular and tissue rejuvenation

First author:
Sengstack J

Journal:
Proc. Natl. Acad. Sci. U.S.A. 2026.123:e2515183123

DOI:
10.1073/pnas.2515183123

Reference:
Sengstack J, Li H, Aghayev T, Bier G, Mobaraki M, Zheng J, Lin J, Deng C, Villeda SA, et al. Systematic identification of single transcription factor perturbations that drive cellular and tissue rejuvenation. Proc. Natl. Acad. Sci. U.S.A. 2026;123:e2515183123. Published January 9, 2026. https://doi.org/10.1073/pnas.2515183123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/ezh2-liver-rejuvenation

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-01-19.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited sections describing the TRDP platform, identification of four rejuvenating TF perturbations, in vitro cellular aging hallmarks, in vivo liver experiments with EZH2, safety considerations, and broader implications of aging as a programmable, reversible state.
- transcript topics: TRDP platform and Perturb-seq workflow; Top rejuvenating TF perturbations: E2F3, EZH2, STAT3, ZFX; In vitro reversal of aging hallmarks in late-passage fibroblasts; In vivo liver rejuvenation in aged mice via EZH2 overexpression; Cancer risk considerations and mesenchymal drift; Broader implications and potential organ-wide applications of TRDP

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- TRDP identifies single TF perturbations that promote rejuvenation without dedifferentiation
- Four TF perturbations (E2F3, EZH2, STAT3, ZFX) reverse aging hallmarks in late-passage human fibroblasts
- EZH2 overexpression in aged mouse liver reverses aging-associated gene expression and improves steatosis, fibrosis, and glucose tolerance within three weeks
- TF perturbations do not induce cancer-like transcriptome changes; no resemblance to oncogenic programs
- Aging may reflect an epigenetic/operating-system-like state that can be reset by targeted TF perturbations
- TRDP has potential for translation to other organs, per discussion in the article

QC result: Pass.

263: Bifacial γPNA triplets target rCUG repeats and displace MBNL1 in Myotonic Dystrophy type 1

Gustavo Barra — Sun, 18 Jan 2026 22:19:16 +0000

Perera J et al., Proc. Natl. Acad. Sci. U.S.A. 2026.123:e2507065123 - Gamma-PNA triplet ligands with Janus bases selectively bind expanded rCUG repeats, displace MBNL1, and show length-dependent cooperativity with partial splicing rescue. Key terms: rCUG repeats, gamma PNA, Janus bases, MBNL1 displacement, myotonic dystrophy type 1.

Study Highlights:
The authors designed compact three-unit bifacial nucleic acid ligands (Janus bases on a γPNA backbone) and evaluated them against rCUG repeat duplexes and DM1 patient-derived myotubes using molecular dynamics, EMSA, SPR, AFM, and cellular splicing assays. MD and EMSA/SPR show cooperative, length-dependent binding with Kd values decreasing to ~0.56 µM for rCUG98 and Hill coefficients rising to ~5, driven by enhanced hydrogen-bonding and π–π stacking between adjacent ligands. AFM revealed a 0.348 nm increase in RNA helix contour height on binding, consistent with a pothole-filling insertion mechanism that selectively recognizes hairpin duplexes over single-stranded RNA. Functionally, a cell-permeable LG2c analog reduced nuclear foci and partially restored mis-splicing of Serca1, cTNT, and IR in DM1 myotubes, though cellular uptake remains limiting.

Conclusion:
Short bifacial γPNA triplet ligands selectively recognize pathogenic rCUG hairpins via a pothole-filling mechanism, displace MBNL1, and can partially restore splicing in DM1 myotubes while cellular delivery requires further optimization.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
A pothole-filling strategy for selective targeting of rCUG-repeats associated with myotonic dystrophy type 1

First author:
Perera J

Journal:
Proc. Natl. Acad. Sci. U.S.A. 2026.123:e2507065123

DOI:
10.1073/pnas.2507065123

Reference:
Perera J. D. R., Thadke S. A., Thrikawala S. W., Wilson W. D., Tan K. W. R., Chand N. Z. W., Phan A. T., Ly D. H., et al. A pothole-filling strategy for selective targeting of rCUG-repeats associated with myotonic dystrophy type 1. Proc. Natl. Acad. Sci. U.S.A. 2026;123:e2507065123. https://doi.org/10.1073/pnas.2507065123

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/pothole-filling-rcug-gamma-pna

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-01-18.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript portions describing (a) design of bifacial Janus bases on a gammaPNA backbone, (b) pothole-filling mechanism and cooperative binding to rCUG repeats, (c) selectivity for long pathogenic repeats vs. short normal repeats, (d) displacement of MBNL1, (e) splicing rescue in DM1 patient-derived myotube
- transcript topics: Janus bases and gammaPNA backbone design; Pothole-filling mechanism and RNA hairpin targeting; Cooperativity and length-dependent binding to rCUG repeats; Pathogenic vs normal repeat selectivity (rCUG98 vs rCUG33); MBNL1 displacement by LG2b; LG2c: cell uptake and rescue of splicing in DM1 myotubes

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- DM1 is driven by expanded rCUG repeats that sequester MBNL1 and disrupt splicing
- Bifacial Janus base ligands on a gammaPNA backbone enable targeted RNA recognition via hydrogen-bonding on two faces
- LG2b binds longer pathogenic rCUG repeats with cooperativity (N ~ 5) and shows length-dependent binding (Kd decreases with longer repeats; e.g., rCUG98 ~0.56 µM)
- LG2b selectively binds pathogenic repeats (rCUG98) and ignores normal repeats (rCUG33)
- AFM evidence shows a 0.348 nm height increase upon LG2b binding, supporting a pothole-filling mechanism
- LG2b can displace MBNL1 from rCUG98 and can prevent binding in competitive formats

QC result: Pass.

262: Human Langerhans cells reprogrammed by tick saliva (CXCR4/CCR7 migration and IDO1/IRF4 tolerance)

Gustavo Barra — Sat, 17 Jan 2026 07:30:11 +0000

Strobl et al., Nature Communications - Human epidermal Langerhans cells exposed to Ixodes ricinus tick saliva and Borrelia burgdorferi adopt a tolerogenic state with CXCR4/CCR7-driven emigration that impairs T cell priming. Key terms: Langerhans cells, tick saliva, Borrelia burgdorferi, CXCR4/CCR7 migration, immune tolerance.

Study Highlights:
The study uses clinical human tick bite biopsies, an ex vivo human skin tick bite model, in vitro monocyte- and CD34-derived Langerhans cells, immune spheroid cultures and single-cell RNA-sequencing of erythema migrans lesions, employing imaging, migration assays, co-cultures and scRNA-seq. Tick salivary gland extract (SGE) up-regulates CXCR4 and CCR7 on LCs, promotes emigration from the epidermis into dermis and lymphatic vessels, and reduces keratinocyte TGF-β consistent with migration. SGE and Borrelia burgdorferi drive up-regulation of tolerogenic transcription factors IDO1 and IRF4 while blunting immunogenic IRF1/NFκB programs, and SGE-primed LCs induce Treg and Th2 bias with reduced Tfh, Th17 and Th9 induction. Functionally, these changes dampen protective adaptive responses in lymphoid models and in patient lesions, which may reduce bacterial clearance and memory formation.

Conclusion:
Tick saliva reprograms human epidermal Langerhans cells to migrate to lymphatics and adopt a tolerogenic program that impairs protective T cell responses and may facilitate Borrelia transmission.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Human epidermal Langerhans cells induce tolerance and hamper T cell function upon tick-borne pathogen transmission

First author:
Strobl

Journal:
Nature Communications

DOI:
10.1038/s41467-025-66821-6

Reference:
Strobl, J., Kleissl, L., Eder, J., Conolly, S., Frey, T., Gail, L. M., Kopf, A., Weninger, S., Markowicz, M., Bartíková, P., Freystätter, C., Schmetterer, K., Strobl, H., Stockinger, H., Wijnveld, M. & Stary, G. Human epidermal Langerhans cells induce tolerance and hamper T cell function upon tick-borne pathogen transmission. Nature Communications. 2025. https://doi.org/10.1038/s41467-025-66821-6

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/langerhans-tick-saliva-tolerance

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-01-17.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the scientific content conveyed in the transcript, focusing on LC migration (CXCR4/CCR7), tolerogenic programming (IDO1/IRF4), and T cell polarization in skin infection and ex vivo models, plus vaccine implications.
- transcript topics: LC migration from epidermis to dermis/lymphatics via CXCR4/CCR7; Tolerogenic transcription factors IDO1 and IRF4 upregulation in LCs; Impact of Borrelia burgdorferi and Staphylococcus aureus on LC polarization; Ex vivo human skin tick bite model and single-cell RNA sequencing findings; Immune spheroid culture model and T cell polarization outcomes; Vaccine implications: targeting tick saliva to prevent transmission

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Tick saliva induces emigration of Langerhans cells from epidermis to dermis and lymphatics (CXCR4/CCR7 upregulation)
- SGE promotes LCs to adopt tolerogenic transcriptional program (IDO1 and IRF4)
- TL interactions shift T cell responses toward Tregs and Th2; dampen Th17/Th9 and Tfh
- Borrelia burgdorferi co-stimulation maintains tolerogenic LC polarization; SGE effects persist
- Lesional erythema migrans skin shows reduced LC density with migratory/tolerogenic signatures
- Ex vivo and scRNA-seq and spheroid models reveal mechanistic LC-T cell interactions that impair protective immunity

QC result: Pass.

261: MHz-XPCS reveals anomalous ferritin diffusion and nanoscale cage trapping

Gustavo Barra — Fri, 16 Jan 2026 08:44:53 +0000

Girelli et al., Nature Communications - MHz-XPCS of ferritin solutions at EuXFEL shows anomalous, cage-trapped protein diffusion with reduced long-time transport and ~1.2 nm rattling at high concentration. Key terms: ferritin, MHz-XPCS, anomalous diffusion, cage effects, hydrodynamic function.

Study Highlights:
The study probes crowded ferritin solutions using megahertz X-ray Photon Correlation Spectroscopy (MHz-XPCS) at EuXFEL combined with SAXS and δγ-theory modeling. Intensity autocorrelation functions g2(q,t) become non-exponential at high concentrations, and double-exponential analysis yields short- and long-time diffusion components with Dlong/Dshort ≈ 0.12 ± 0.04 at 730 mg/ml and an interaction time estimated near 4.25 µs. δγ-theory of hydrodynamically interacting spheres reproduces the q-dependent hydrodynamic function only when a scaling factor tied to direct protein interactions is included, indicating hydrodynamics set the q-dependence while direct forces reduce overall self-diffusion. Cage analysis finds an average rattling displacement δ ≈ 1.0 ± 0.3 nm for ≈89% of proteins, implying cage-trapping substantially slows molecular transport with consequences for ferritin-based drug delivery.

Conclusion:
MHz-XPCS measurements and δγ-theory modeling demonstrate that crowded ferritin solutions exhibit anomalous, cage-trapped diffusion with separate short- and long-time components and markedly reduced self-diffusion, indicating slower molecular transport under crowding.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Coherent X-rays reveal anomalous molecular diffusion and cage effects in crowded protein solutions

First author:
Girelli

Journal:
Nature Communications

DOI:
10.1038/s41467-025-66972-6

Reference:
Girelli, A., Bin, M., Filianina, M. et al. Coherent X-rays reveal anomalous molecular diffusion and cage effects in crowded protein solutions. Nat Commun (2025). https://doi.org/10.1038/s41467-025-66972-6

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) - https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/ferritin-anomalous-diffusion-xpcs

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-01-16.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the spoken content for the central findings and methods: crowded diffusion in ferritin solutions, MHz-XPCS techniques at EuXFEL, evidence for cage trapping, two diffusion regimes (Dshort and Dlong), interaction time, cage displacement, δγ-theory modeling with a scaling factor, and implications for diffusion in
- transcript topics: Crowding and diffusion in cellular-like environments; MHz-XPCS methodology at EuXFEL; Ferritin as a model system; Anomalous diffusion and cage effects; Short-time vs long-time diffusion; Two-component diffusion: Dshort and Dlong

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Anomalous diffusion observed in crowded ferritin solutions
- Cage trapping as a mechanism for constrained diffusion under crowding
- Two diffusion components: short-time Dshort and long-time Dlong
- Interaction time τi for ferritin ~ 4.25 µs in crowded conditions
- Cage occupancy A0 ≈ 89% of proteins
- Cage displacement δ ≈ 1.0 ± 0.3 nm (with discussion suggesting δ ≈ 1.2 ± 0.6 nm)

QC result: Pass.

260: TSS hypermutability in human germline linked to RNAP II stalling, R-loops and early embryonic mosaics

Gustavo Barra — Thu, 15 Jan 2026 00:18:50 +0000

Nature Communications - Transcription start sites experience a high influx of heritable variants fueled by early development

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Transcription start sites experience a high influx of heritable variants fueled by early development

Journal:
Nature Communications

DOI:
10.1038/s41467-025-66201-0

License:
CC BY 4.0 International License

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-01-15.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript for core germline mutagenesis mechanisms around transcription start sites (TSS), mosaic vs de novo variation, mechanistic links (RNAP II stalling, R-loops, divergent transcription), mutational signatures, purifying selection, disease links, and clinical implications as described in the article.
- transcript topics: Germline TSS mutational hotspot; Extremely rare variants and mosaicism; De novo mutations vs mosaic filtering; Transcription-associated mutagenesis mechanisms (RNAP II stalling, R-loops, divergent transcription); Mutational signatures (SBS3, SBS40b, SBS40c; SBS39 maternal clusters; SBS12/SBS16); Divergent transcription at promoters

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Germline transcription start sites harbor a mutational hotspot spanning several hundred base pairs upstream and downstream of the TSS
- Non(CpG > TpG) variations show a mutational excess at the TSS, up to ~35% in 100-bp windows around the TSS
- De novo mutations (DNMs) do not show a significant TSS excess due to misclassification/ filtering; the hotspot is revealed by mosaic variants
- Early mosaic mutations are enriched near the TSS, with a 52% excess immediately downstream of the TSS
- Divergent transcription, RNAP II stalling, and R-loop formation are associated with the TSS hotspot
- Mutational signatures SBS3, SBS40b, SBS40c indicate non-canonical DSB repair; SBS39 linked to maternal mutation clusters

QC result: Pass.

259: Ku filaments that hold DNA together

Gustavo Barra — Wed, 14 Jan 2026 06:12:18 +0000

Zahid S et al., Nature Communications, doi:10.1038/s41467-025-65609-y - Cryo-EM and biophysical analyses show Mycobacterium tuberculosis Ku assembles into DNA-bound oligomeric filaments that synapse DNA ends and are required for survival under DNA-damaging conditions. Key terms: Ku-Mtb, non-homologous end joining, cryo-EM, DNA synapsis, Mycobacterium tuberculosis.

Study Highlights:
Deletion of ku in M. smegmatis causes marked survival defects after methyl methanesulfonate exposure and desiccation that are rescued by complementation. Cryo-EM structures of apo-Ku-Mtb (4.04 Å) and DNA-bound Ku-Mtb (2.96 Å) reveal a homodimer that assembles into extended filaments with a minimal repeating unit of two homodimers per DNA duplex. Biophysical assays (mass photometry, FIDA, AFM) and positive-stain EM confirm DNA-induced oligomerisation and show Ku can circularize DNA ends, holding them ~40 Å apart. Mutation of hydrophobic loop residues L13/V14 abolishes filament formation while preserving DNA binding and reduces bacterial survival, and the C-terminal α-helix blocks the filament interface in the apo state and is displaced on DNA binding to enable LigD recruitment.

Conclusion:
Ku oligomerisation mediates DNA end synapsis during bacterial NHEJ and is critical for mycobacterial survival under DNA-damaging stresses

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Oligomerisation of Ku from Mycobacterium tuberculosis promotes DNA synapsis

First author:
Zahid S

Journal:
Nature Communications, doi:10.1038/s41467-025-65609-y

DOI:
10.1038/s41467-025-65609-y

Reference:
Zahid S, Baconnais S, Smith H, Atwal S, Bates L, Read H, Chadda A, Morati F, Stender EGP, Westerlund F, Galburt E, Mukamolova GV, Chaplin AK, et al. Oligomerisation of Ku from Mycobacterium tuberculosis promotes DNA synapsis. Nature Communications. 2025;16:10568. https://doi.org/10.1038/s41467-025-65609-y

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/ku-mtb-dna-synapsis

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-01-14.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the spoken content covering MTB NHEJ, Ku-Mtb filament formation on DNA, cryo-EM structural details, mutational analyses, functional assays, and therapeutic implications.
- transcript topics: Ku essential for mycobacterial survival under MMS-induced DNA DSBs; Desiccation tolerance and MTB DNA repair via NHEJ; apo-Ku-Mtb structure by cryo-EM (4.04 Å) and DNA-bound filament (2.96 Å); DNA synapsis by Ku-Mtb filament; ~40 Å end-to-end distance; Minimal repeating unit: two Ku-Mtb homodimers per DNA duplex; Role of C-terminal helix and L13/V14 hydrophobic interface in filament regulation

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Ku-Mtb forms an extended filament on DNA and synapses DNA ends; minimal unit is two Ku-Mtb homodimers per DNA duplex
- DNA ends are held at a distance of approximately 40 Å within the filament
- Leu13 and Val14 form a hydrophobic interface critical for filament formation; L13A/V14A abolishes filament formation
- The C-terminus acts as an autoinhibitory regulatory arm; displacement upon DNA binding enables filament formation and LigD recruitment
- MTB NHEJ is a minimalist system lacking vWA domains and DNA-PKcs, capable of synapsis without the large human machinery
- Mutational analysis in vivo (L23A/L24A equivalent) reduces survival under DNA-damaging stress

QC result: Pass.

258: Correcting GC bias in metagenomes

Gustavo Barra — Tue, 13 Jan 2026 21:19:06 +0000

Holcik L et al., Nature Communications, doi:10.1038/s41467-025-65530-4 - GuaCAMOLE is an alignment-free algorithm that estimates and removes genomic GC-content-dependent sequencing bias to produce more accurate species abundance estimates from single metagenomic samples. Key terms: GC bias, metagenomics, species abundance, GuaCAMOLE, colorectal cancer.

Study Highlights:
GuaCAMOLE combines Kraken2/Bracken read assignment with per-taxon GC binning and a regularized least-squares estimator to infer GC-dependent sequencing efficiencies and bias-corrected abundances from a single sample. On simulations and mock communities across 28 library protocols it produced near-unbiased estimates and outperformed Bracken and MetaPhlAn4 when GC bias was present. Application to 3,435 gut microbiomes from 33 colorectal cancer studies revealed four distinct protocol-specific GC-bias shapes and systematic underestimation of GC-poor taxa. The tool also filters false-positive taxa by comparing observed and expected GC distributions and can apply inferred efficiencies to correct other tools' outputs.

Conclusion:
Per-sample GC-bias correction with GuaCAMOLE improves accuracy and comparability of metagenomic species abundance estimates across diverse protocols

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Genomic GC bias correction improves species abundance estimation from metagenomic data

First author:
Holcik L

Journal:
Nature Communications, doi:10.1038/s41467-025-65530-4

DOI:
10.1038/s41467-025-65530-4

Reference:
Holcik L., von Haeseler A., Pflug F. G. Genomic GC bias correction improves species abundance estimation from metagenomic data. Nature Communications. 2025;16:10523. https://doi.org/10.1038/s41467-025-65530-4

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/gc-bias-correction-metagenomics

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-01-13.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript content for core scientific claims and results described in the article, including GC bias problems in metagenomics, the GuaCAMOLE algorithm, GC-bin strategy and QC, benchmarking results (simulated and mock data), CRC meta-analysis findings, and limitations/future work.
- transcript topics: GC bias in metagenomic sequencing; GuaCAMOLE algorithm overview and alignment-free design; GC-bin read counting and abundance estimation; False-positive taxon filtering and QC; Benchmarking on simulated data and mock communities; Four GC-bias shapes across colorectal cancer gut microbiomes

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- GC content affects sequencing efficiency and biases vary by protocol
- GuaCAMOLE is alignment-free and uses Kraken2/Bracken for initial taxon assignment with GC-bin stratification
- Abundances and GC-dependent sequencing efficiencies are solved simultaneously via least-squares estimation
- False-positive taxa are screened via GC-distribution outlier detection
- Simulated data show mean relative error < 1% for GuaCAMOLE versus 10–30% for Bracken
- Mock community across 28 protocols reveals four distinct GC-efficiency shapes

QC result: Pass.

257: PSMC5: proteasomes, immunity and neurodevelopment

Gustavo Barra — Mon, 12 Jan 2026 06:21:26 +0000

Küry S et al., Nature Communications, doi:10.1038/s41467-025-65556-8 - This study describes 26 distinct PSMC5 variants in 44 individuals and demonstrates that PSMC5 loss impairs proteasome function, driving proteotoxic stress, mitochondrial and lipid dysregulation, sterile type I interferon activation, and neurodevelopmental deficits. Key terms: PSMC5, proteasome, neurodevelopment, interferon, mitophagy.

Study Highlights:
Twenty-six distinct PSMC5 variants were identified in 44 affected individuals, mostly heterozygous and de novo, clustering in the AAA+ ATPase domain and predicted to be pathogenic. Functional assays and patient T cells show that many variants perturb PSMC5 incorporation into 26S proteasomes, reduce proteasome activity, and increase ubiquitin-positive aggregates and aggresomes. Multi-omics of patient T cells revealed disrupted mitochondrial proteostasis with increased mitophagy, altered glycerophospholipid profiles and impaired ribosome biogenesis. Neuronal models and Drosophila demonstrate reduced excitatory synapses, E/I imbalance, impaired neuritogenesis, deficits in reversal learning and compromised NPC differentiation, while ISR kinases PKR and GCN2 plus cGAS-STING and JAK pathways mediate a spontaneous type I IFN response that can be pharmacologically reduced.

Conclusion:
PSMC5 variants cause proteasome loss-of-function that links proteotoxic stress to innate immune activation and impaired neurogenesis, identifying ISR and JAK pathway components as potential therapeutic targets.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Investigating the neuronal role of the proteasomal ATPase subunit gene PSMC5 in neurodevelopmental proteasomopathies

First author:
Küry S

Journal:
Nature Communications, doi:10.1038/s41467-025-65556-8

DOI:
10.1038/s41467-025-65556-8

Reference:
Küry S, Bézieau S, Ebstein F, et al. Investigating the neuronal role of the proteasomal ATPase subunit gene PSMC5 in neurodevelopmental proteasomopathies. Nature Communications. 2025;16:10545. https://doi.org/10.1038/s41467-025-65556-8

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/psmc5-proteasome-neurodevelopment

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-01-12.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the spoken content describing PSMC5/UPS biology, variant effects, multi-model analyses (Drosophila, rat neurons, iPSC-derived NPCs), ISR and IFN signaling, lipid/mitophagy changes, synaptic balance, and therapeutic implications.
- transcript topics: PSMC5 and 26S proteasome function; PSMC5 variants and neurodevelopmental proteasomopathies; Proteotoxic stress and aggresome formation; Mitochondrial dysfunction and mitophagy; Lipid metabolism dysregulation; Integrated stress response (PKR/GCN2) and type I interferon signaling

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- 26 distinct PSMC5 variants identified in 44 individuals
- Variants cluster in the AAA+ ATPase domain; Arg325Trp recurring
- Loss of PSMC5 function impairs proteasome activity, causing proteotoxic stress and aggresome formation
- Mitophagy is increased and lipid metabolism is disrupted (50% increase in cholesterol esters; decreased glycerophospholipids)
- Transcriptomic/type I IFN signature elevated in patient T cells; ISR mediates IFN induction; PKR/GCN2 inhibitors reduce IFN scores; baricitinib (JAK inhibitor) also reduces IFN sco
- Arg325Trp variant impairs neural progenitor cell differentiation in iPSC models

QC result: Pass.

256: Compartmental control of VSG silencing

Gustavo Barra — Sun, 11 Jan 2026 19:39:49 +0000

Antunes et al., Nature Communications - The study shows that spatial segregation of core and subtelomeric chromosome compartments, demarcated by protein-rich boundaries and controlled by a phosphoinositide regulator, is required to silence subtelomeric VSG genes. Key terms: RAP1, PIP5Pase, VSG, Hi-C, chromatin.

Study Highlights:
Hi-C and Pore-C reveal that T. brucei chromosomes are organized into transcribed core (A) and repressed subtelomeric (B) compartments that contain TADs and loops. XLMS and ChIP-seq identify compartment-boundary proteins including RAP1, HDAC1, HAT1 and BDF2, with RAP1 spreading across silent subtelomeric regions. Boundaries from multiple chromosomes co-interact and are enriched for repeat motifs resembling telomeric and centromeric sequences. Inactivation or knockdown of the PIP5Pase regulator disrupts intra-compartment contacts, displaces RAP1 from boundaries and subtelomeres, and activates hundreds of silent VSG genes.

Conclusion:
Assembly of chromosome compartments and PIP5Pase-regulated RAP1 binding are essential for subtelomeric VSG gene silencing in T. brucei.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Chromosome compartment assembly is essential for subtelomeric gene silencing in trypanosomes

First author:
Antunes

Journal:
Nature Communications

DOI:
10.1038/s41467-025-66824-3

Reference:
Antunes, L.B., Isebe, T., Kutova, O. et al. Chromosome compartment assembly is essential for subtelomeric gene silencing in trypanosomes. Nat Commun (2025). https://doi.org/10.1038/s41467-025-66824-3

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/compartment-vsg-silencing

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-01-11.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Substantive auditing focused on the transcript’s coverage of 3D genome compartments (A/B), boundary proteins (RAP1, BDF2, HAT1, HDAC1, ZCW1, etc.), XLMS/SPR validation, Hi-C vs Pore-C insights, and the PIP5Pase–PI(3,4,5)P3–RAP1 axis governing VSG silencing and the consequences of PIP5Pase knockdown or catalytic inactiv
- transcript topics: VSG gene silencing and monoallelic expression; A/B chromosome compartments and 3D genome organization; RAP1 boundaries and subtelomeric spread; PIP5Pase and PI(3,4,5)P3 signaling regulating RAP1; XLMS network and SPR validation of interactions; Hi-C and Pore-C mapping of TADs/loops and boundary interactions

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Subtelomeric VSG silencing is coupled to chromosome compartmentalization into core (A) and subtelomeric (B) compartments
- RAP1 localizes at compartment boundaries and spreads across subtelomeric regions to enforce silencing
- PIP5Pase dephosphorylates PI(3,4,5)P3, maintaining RAP1 DNA binding and subtelomeric repression
- PIP5Pase knockdown disrupts intra-compartment contacts, displaces RAP1 from boundaries/subtelomeres, and derepresses subtelomeric VSG genes
- Hi-C and Pore-C identify A/B compartments, TADs, and chromatin loops; boundaries co-interact
- Catalytically inactive PIP5Pase displaces RAP1 and derepresses subtelomeric VSG genes

QC result: Pass.

255: Lipids, Ions and the AE1 Elevator

Gustavo Barra — Sat, 10 Jan 2026 08:32:44 +0000

Chen T et al., Nature Communications - Cryo-EM structures, uptake assays, and molecular dynamics show that PIP2 lipids bind at the AE1 dimer interface and inhibit the OF⇌IF conformational transition while substrate binding lowers the transition barrier. Key terms: AE1, PIP2, bicarbonate transport, cryo-EM, molecular dynamics.

Study Highlights:
Three high-resolution cryo-EM states were solved: two inward-facing (IF1, IF2) and one outward-facing (OF). Proteoliposome uptake assays show that depleting or masking PIP2 increases HCO3– and I– transport. MD simulations identify recurring anion binding in the lumen with R730 as a key coordinating residue and estimate tighter HCO3– binding than Cl–. Enhanced-sampling free energy profiles reveal that HCO3– binding lowers the OF⇌IF barrier by ~3 kcal/mol while removing PIP2 lowers it by ~2 kcal/mol. Mechanistically, HCO3– stabilizes a transition-state conformation by promoting R730 contact with the scaffold domain.

Conclusion:
PIP2 stabilizes AE1 in a conformation that raises the transport transition barrier and inhibits activity, whereas substrate binding promotes the transition and facilitates transport.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Impact of anionic lipids on the energy landscape of conformational transition in anion exchanger 1 (AE1)

First author:
Chen T

Journal:
Nature Communications

DOI:
10.1038/s41467-025-66786-6

Reference:
Chen T, Vallese F, Gil-Iturbe E, Kim K, Calì T, Quick M, Clarke OB, Tajkhorshid E. Impact of anionic lipids on the energy landscape of conformational transition in anion exchanger 1 (AE1). Nature Communications. 2025. https://doi.org/10.1038/s41467-025-66786-6

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/pipt2-inhibits-ae1

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-01-10.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript sections describing AE1 elevator mechanism (TD/SD), R730 and ion binding, bicarbonate vs chloride affinity, PIP2 as a regulatory brake, energy landscape via BEUS/SMwST, cross-linking to trap IF, and the three-state (OF, IF1, IF2) structural context, plus functional uptake assays.
- transcript topics: AE1 elevator mechanism (TD/SD architecture); R730 and luminal anion binding sites; Bicarbonate vs chloride binding affinities (Kd values); PIP2 binding site at the dimer interface and K743 salt bridge; PIP2 as molecular brake and its removal increasing activity; Energy landscape and conformational transitions (BEUS/SMwST)

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- PIP2 binds at the AE1 dimer interface and inhibits the OF⇌IF conformational transition.
- Substrate binding (HCO3−) lowers the transition barrier by ~3 kcal/mol.
- PIP2 binding raises the transition barrier by ~2 kcal/mol; removal lowers it.
- R730 is a key coordinating residue for bicarbonate and chloride binding in AE1 lumen.
- HCO3− binding affinity is higher than Cl− in both OF and IF states (Kd values reported).
- AE1 operates via an elevator mechanism with TD translating/rotating relative to SD.

QC result: Pass.

254: Rescuing the replisome at a nick

Gustavo Barra — Fri, 09 Jan 2026 08:11:53 +0000

Winterhalter et al., Nature Communications - Cas9 nickases in Bacillus subtilis show that single-strand nicks in either template strand arrest DNA replication, create single-end double-strand breaks, and require homologous recombination plus PriA-dependent helicase reloading for replication restart. Key terms: DNA replication, recombinational repair, AddAB, PriA, SSB.

Study Highlights:
Site-specific nicks created with Cas9D10A block DNA synthesis downstream of the nick and induce RecA bundling in live cells. ChIP-qPCR shows helicase enrichment upstream of nicks and persistence downstream when the leading strand template is nicked, indicating helicase runs off the template for lagging-strand nicks but translocates onto dsDNA for leading-strand nicks. Genetic and marker frequency analyses identify AddAB helicase activity, RecFOR, RecA, RecG and PriA as essential for repair and PriA-dependent helicase reloading to resume replication. SSB C-terminal tail is required to recruit RecO and enable RecA loading, while AddAB nuclease activity is largely dispensable if helicase activity and an alternative nuclease provide ssDNA.

Conclusion:
B. subtilis repairs replisome inactivation at single-strand discontinuities via AddAB-mediated end-processing, RecFOR/RecA-mediated recombination, and PriA-dependent helicase reloading to restart replication

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Rescuing the bacterial replisome at a nick requires recombinational repair and helicase reloading

First author:
Winterhalter

Journal:
Nature Communications

DOI:
10.1038/s41467-025-66550-w

Reference:
Winterhalter, C., Stratton, K.J., Fenyk, S. et al. Rescuing the bacterial replisome at a nick requires recombinational repair and helicase reloading. Nat Commun (2025). https://doi.org/10.1038/s41467-025-66550-w

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/replisome-nick-repair

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-01-09.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript’s presentation of the nickase system, replication arrest, downstream molecular events (AddAB end-processing, SSB recruitment, RecFOR/RecA loading, RecG/RecU roles), PriA-dependent helicase reloading, and the manuscript’s implications for antibiotic strategies.
- transcript topics: Cas9 nickase system in Bacillus subtilis; Replication arrest and MFA evidence; Fate of helicase at leading vs lagging strand nick; PriA-dependent replication restart pathway; AddAB end-processing and SSB recruitment; RecFOR-mediated RecA loading via SSB-CTT

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Cas9 nickase system creates site-specific nicks in Bacillus subtilis
- Nick on either leading or lagging strand arrests replication downstream
- Replication restart requires recombinational repair and PriA-dependent restart
- AddAB helicase activity is necessary for end-processing; nuclease activity dispensable
- SSB C-terminal tail is required for efficient recombinational repair via RecO recruitment
- RecFOR mediates displacement of SSB to allow RecA loading onto ssDNA

QC result: Pass.

253: Nap1 and histone acetylation tune chromatin condensates

Gustavo Barra — Thu, 08 Jan 2026 06:17:53 +0000

Gao J et al., Nature Communications - H4 tail lysine residues drive liquid-liquid phase separation of 12‑mer nucleosome arrays, while H3 tail acetylation and the histone chaperone Nap1 increase internal dynamics and lower droplet viscosity. Key terms: Nap1, H3 acetylation, H4 acetylation, liquid-liquid phase separation, nucleosome arrays.

Study Highlights:
H4 tail lysine residues are the primary drivers of nucleosome array phase separation, and H4-tail acetylation prevents droplet formation. H3 tail acetylation mimic (H3KQ) and in situ H3 acetylation speed fluorescence recovery, indicating enhanced DNA–histone dynamics. Nap1 dissolves gel-like aggregates formed by tailless H3 arrays, increases nucleosome concentration inside droplets from ~326 µM to ~491 µM, and accelerates internal dynamics. STORM imaging reveals condensed droplets contain both a mobile fraction and a relatively immobile structural scaffold. Optical-tweezers microrheology identifies two relaxation components and shows Nap1 and H3KQ specifically lower the relaxation time and viscosity of the slower scaffold-associated component

Conclusion:
Histone H4 tail lysines govern chromatin phase separation while H3 acetylation and Nap1 tune the fluidity and accessibility of condensed chromatin

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Roles of histone chaperone Nap1 and histone acetylation in regulating phase-separation of nucleosome arrays

First author:
Gao J

Journal:
Nature Communications

DOI:
10.1038/s41467-025-65701-3

Reference:
Gao J, Li H, Tan S, Zhou R & Lee T-H. Roles of histone chaperone Nap1 and histone acetylation in regulating phase-separation of nucleosome arrays. Nature Communications. 2025;16:10672. https://doi.org/10.1038/s41467-025-65701-3

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/nap1-histone-acetylation

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-01-08.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Substantively audited sections cover the core biophysical mechanisms and measurements: LLPS initiation by H4 tail, effects of H4KQ and H3KQ on droplet formation and dynamics, Nap1’s dual role, FRAP, STORM, microrheology with two relaxation components, and H2A–H2B exchange context.
- transcript topics: LLPS of nucleosome arrays driven by H4 tail lysines; H4KQ acetylation mimic blocks droplet formation; H3 tail acetylation mimic (H3KQ) increases dynamics but does not block LLPS; Nap1 dissolves aggregates and increases nucleosome concentration inside condensates; STORM reveals mobile fraction and immobile scaffold inside droplets; Microrheology with optical traps identifying two relaxation components

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- H4 tail lysine residues drive LLPS of nucleosome arrays
- H4KQ acetylation mimic blocks droplet formation
- H3KQ acetylation mimic increases dynamics but does not block condensation
- Nap1 dissolves chromatin aggregates and increases nucleosome concentration inside condensates
- Condensates contain a mobile fraction and a relatively immobile structural scaffold
- Nap1 and H3KQ reduce the slower component's viscosity and shorten its relaxation time

QC result: Pass.

252: Keratinocytes to cSCC: genetic steps

Gustavo Barra — Wed, 07 Jan 2026 05:42:21 +0000

Deivendran D et al., Nature Communications, doi:10.1038/s41467-025-65687-y - Single-cell and spatial multi-omic profiling maps the genetic and transcriptional changes from normal keratinocytes through actinic keratoses to invasive cutaneous squamous cell carcinoma. Key terms: keratinocytes, actinic keratosis, TP53, ARID2, spatial transcriptomics.

Study Highlights:
Single-cell genotyping of 137 keratinocytes revealed most cells have low mutation burdens (median 1.14 mut/Mb) while keratinocytes with TP53 or NOTCH1 mutations carry substantially higher burdens. Deep panel sequencing of 16 paired actinic keratoses and adjacent cSCCs showed TERT promoter and CDKN2A mutations arise in actinic keratoses and additional events such as ARID2 loss and MAPK pathway activation delineate progression to cSCC. Many actinic keratoses were genetically unrelated to their neighboring cSCCs, indicating independent clonal origins despite spatial proximity. Spatial transcriptomics exposed intratumoral heterogeneity and enrichment of immune checkpoint molecules at invasive fronts, implicating localized immune modulation.

Conclusion:
Keratinocyte transformation to cSCC follows a stereotyped sequence where TP53/NOTCH1-associated mutator phenotypes prime cells for acquisition of telomerase activation and cell-cycle defects in precursors, with SWI/SNF disruption and MAPK activation driving invasion alongside spatial immune evasion.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Genetic evolution of keratinocytes to cutaneous squamous cell carcinoma

First author:
Deivendran D

Journal:
Nature Communications, doi:10.1038/s41467-025-65687-y

DOI:
10.1038/s41467-025-65687-y

Reference:
Deivendran D, Chen L, Tandukar B, Bandari AK, Cruz-Pacheco N, Sharma H, Wang M, Xu A, Chen DB, George CD, Marty AL, Cho RJ, Cheng JB, Saylor D, Gerami P, Yeh I, Arron ST, Bastian BC, Shain AH. Genetic evolution of keratinocytes to cutaneous squamous cell carcinoma. Nature Communications. 2025;16:10663. https://doi.org/10.1038/s41467-025-65687-y

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/keratinocytes-to-cscc-evolution

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-01-07.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the spoken content for keratinocyte mutational landscape, mutator phenotype, clonal architecture, AK adjacency to cSCC, SWI/SNF (ARID2) disruption, MAPK activation, spatial transcriptomics, immune evasion, and translational implications.
- transcript topics: Keratinocyte mutation burden in normal skin; Mutator phenotype driven by TP53/NOTCH1 mutations; Single-cell clonality and deep sequencing depth; Actinic keratosis to squamous cell carcinoma progression; ARID2 SWI/SNF disruption and MAPK pathway in invasion; Spatial transcriptomics and intratumoral heterogeneity

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Keratinocytes in normal skin have a low mutation burden (median around 1 mut/Mb)
- Keratinocytes with TP53 or NOTCH1 mutations show substantially higher mutation burdens (up to ~49.71 mut/Mb)
- Clonal expansion yielded colonies of about 200 cells for sequencing
- Actinic keratoses adjacent to cSCCs are not always clonally related to the neighboring cSCC

QC result: Pass.

251: MuSCs, laminin-α2 and LAMA2 MD

Gustavo Barra — Tue, 06 Jan 2026 22:33:15 +0000

McGowan TJ et al., Nature Communications, doi:10.1038/s41467-025-65703-1 - Activated muscle stem cells express and secrete laminin-α2 to remodel their niche, and loss of MuSC-derived laminin-α2 slows MuSC proliferation and delays regeneration in mouse models and human iPSC-derived precursors. Key terms: laminin-α2, muscle stem cells, LAMA2 MD, regeneration, proliferation.

Study Highlights:
Activated MuSCs upregulate Lama2 and deposit laminin-α2 around proliferating cells during early regeneration. MuSCs from Lama2-deficient dyW/dyW mice progress more slowly through S phase, accumulate in G1, and show reduced expansion ex vivo and in vivo. Transplantation of dyW/dyW MuSCs into wild-type muscle does not restore their proliferative capacity, indicating a cell-intrinsic defect. A MuSC-specific Lama2 knockout recapitulates the slower proliferation and reduces early injury-associated laminin-α2, delaying muscle repair. Isogenic human LAMA2 knockout myogenic precursors also incorporate less EdU and show transcriptional changes consistent with impaired cell-cycle progression.

Conclusion:
Self-secreted laminin-α2 is required cell-autonomously for efficient MuSC proliferation and timely muscle regeneration, implicating MuSC dysfunction as a contributor to LAMA2-related muscular dystrophy pathology

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Loss of cell-autonomously secreted laminin-Î±2 drives muscle stem cell dysfunction in LAMA2-related muscular dystrophy

First author:
McGowan TJ

Journal:
Nature Communications, doi:10.1038/s41467-025-65703-1

DOI:
10.1038/s41467-025-65703-1

Reference:
McGowan TJ, Reinhard JR, Lewerenz N, Białobrzeska M, Lin S, Stępniewski J, Szade K, Dulak J & Rüegg MA. Loss of cell-autonomously secreted laminin-Î±2 drives muscle stem cell dysfunction in LAMA2-related muscular dystrophy. Nature Communications (2025) 16:10674. https://doi.org/10.1038/s41467-025-65703-1

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/muscle-stem-laminin-alpha2

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-01-06.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Substantively audited the transcript’s coverage of: MuSC expression/secreted laminin-α2; intrinsic MuSC proliferation defects in dyW/dyW mice; transplantation results; MuSC-specific Lama2 knockout; human LAMA2 KO hiPSC model; and downstream signaling/cell-cycle implications.
- transcript topics: MuSC activation and Lama2 expression; MuSC secretion and remodeling with laminin-α2; dyW/dyW mouse model: regeneration defects and MuSC proliferation; ex vivo MuSC proliferation assays (EdU, cell cycle); MuSC transplantation experiments and intrinsic vs extrinsic defect; MuSC-specific Lama2 knockout effects on proliferation

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Activated MuSCs express Lama2 and deposit laminin-α2 into their microenvironment
- MuSC-derived laminin-α2 is essential for rapid MuSC expansion and timely muscle regeneration
- Lama2-deficient MuSCs proliferate more slowly ex vivo and show delayed regeneration in dyW/dyW mice
- Transplantation of Lama2-deficient MuSCs shows reduced tissue remodeling capacity in vivo
- MuSC-specific Lama2 knockout slows MuSC proliferation and delays regeneration
- LAMA2 knockout in human hiPSCs slows cell-cycle progression and downregulates G2/M and E2F-related pathways (p53 pathway up)

QC result: Pass.

250: CIP2A–TOPBP1: Mitotic repair via MiDAS and MMEJ

Gustavo Barra — Mon, 05 Jan 2026 05:21:56 +0000

Nieminuszczy J et al., Nature Communications, doi:10.1038/s41467-025-65594-2 - This study shows the CIP2A-TOPBP1 complex coordinates two mitotic double-strand break repair pathways, MiDAS and MMEJ, by recruiting SLX4/SMX components and Polθ to mitotic chromatin. Key terms: CIP2A, TOPBP1, SLX4, MiDAS, MMEJ.

Study Highlights:
TOPBP1 BRCT1/2 binds SLX4 phosphorylated at Thr1260, a CDK1-dependent modification that promotes recruitment of SLX4, MUS81 and ERCC1 to mitotic chromatin to drive MiDAS. CIP2A is required for mitotic chromatin localisation of both TOPBP1 and Polθ, enabling Polθ-dependent MMEJ. Loss of CIP2A impairs both MiDAS and MMEJ, increasing micronuclei, γH2AX and 53BP1 and reducing proliferation under replication stress. Pharmacological Polθ inhibition combined with disruption of the TOPBP1–SLX4 interaction further elevates genome instability and selectively limits growth of BRCA1/2-deficient cells.

Conclusion:
The CIP2A-TOPBP1 axis is a central mitotic DNA repair hub that integrates CDK1-dependent phosphorylation and Polθ recruitment to safeguard genome stability and represents a therapeutic vulnerability in HR-deficient tumors.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
The CIP2A-TOPBP1 axis facilitates mitotic DNA repair via MiDAS and MMEJ

First author:
Nieminuszczy J

Journal:
Nature Communications, doi:10.1038/s41467-025-65594-2

DOI:
10.1038/s41467-025-65594-2

Reference:
Nieminuszczy J, Kozik Z, Jakub N, Vorhauser J, Lane KA, Martin PR, Kowalski S, Lecot M, Kanellou A, Mansfeld J, Pearl LH, Oliver AW, Downs JA, Niedzwiedz W, Choudhary JS, Day M, et al. The CIP2A-TOPBP1 axis facilitates mitotic DNA repair via MiDAS and MMEJ. Nature Communications. 2025;16:10623. https://doi.org/10.1038/s41467-025-65594-2

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/cip2a-topbp1-mitotic-repair

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-01-05.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript portions describing the CIP2A-TOPBP1 axis, MiDAS and MMEJ pathways, the SLX4 Thr1260 phosphorylation by CDK1, TOPBP1-SMX interactions, CIP2A’s regulation of Polθ and SMX components, and the BRCA1/2-deficient synthetic lethal context, plus experimental approaches referenced (co-IP/MS, CRISPR knock
- transcript topics: CIP2A-TOPBP1 axis as a mitotic DNA repair hub; MiDAS and SMX complex recruitment to mitotic chromatin; MMEJ and Polθ dependence in mitosis; CDK1-dependent phosphorylation of SLX4 Thr1260 and TOPBP1 interaction; TOPBP1 BRCT1/2-mediated SMX recruitment and AlphaFold modelling; CIP2A upstream regulation of SLX4 and Polθ localization

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- CIP2A-TOPBP1 axis coordinates mitotic DNA repair by promoting MiDAS and MMEJ
- CDK1-dependent phosphorylation of SLX4 at Thr1260 enables TOPBP1 BRCT1/2 interaction and SMX recruitment for MiDAS
- TOPBP1 BRCT1/2 mediate binding to SMX components; BRCT0-2 suffices for interaction
- CIP2A loss impairs both MiDAS (MiDAS-like BIR) and MMEJ, reducing recruitment of SMX and Polθ
- Polθ recruitment to mitotic chromatin is CIP2A-dependent; CIP2A depletion reduces Polθ localization and MMEJ activity
- BRCA1/2-deficient cells exhibit synthetic lethality when CIP2A-TOPBP1 axis is disrupted

QC result: Pass.

249: PCM1 links centrosome asymmetry to endosome dynamics

Gustavo Barra — Sun, 04 Jan 2026 20:42:17 +0000

Zhao X et al., Nature Communications - In developing neural progenitors PCM1 localizes to the mother centrosome and to Notch ligand-containing endosomes, promoting Par-3/dynein assembly and Rab5-to-Rab11 trafficking to bias posterior-directed endosome segregation and preserve progenitor fate. Key terms: PCM1, centrosome asymmetry, endosome dynamics, radial glia progenitors, Notch signaling.

Study Highlights:
Pcm1 is asymmetrically enriched at the posterior mother centrosome (Cep83+) in zebrafish radial glia progenitors and is also found on central-zone Notch ligand (Dld)-containing endosomes. In vivo time-lapse imaging and expansion microscopy show Pcm1 puncta move with Dld endosomes and promote posterior-directed polarized dynamics. Loss of pcm1 disrupts Rab5b-to-Rab11a trafficking, reduces Par-3 and dynein co-assembly on recycling endosomes, lowers Notch signaling, and shifts divisions toward neuron–neuron outcomes at the expense of progenitors. Similar PCM1–PARD3–CEP83–RAB11 associations and asymmetric PCM1 distribution are observed in human iPSC-derived neural rosettes and cortical organoids.

Conclusion:
PCM1 couples centrosome asymmetry to polarized recycling endosome trafficking to enforce asymmetric Notch signaling and maintain radial glia progenitor fate

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
PCM1 coordinates centrosome asymmetry with polarized endosome dynamics to regulate daughter cell fate

First author:
Zhao X

Journal:
Nature Communications

DOI:
10.1038/s41467-025-65756-2

Reference:
Zhao X., Mouilleau V., Wang Y., Solak A.C., Garcia J.Q., Chen X., Shi X., Wilkinson C.J., Royer L.A., Dong Z. & Guo S. PCM1 coordinates centrosome asymmetry with polarized endosome dynamics to regulate daughter cell fate. Nature Communications. 2025;16:10728. https://doi.org/10.1038/s41467-025-65756-2

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/pcm1-centrosome-endosome-asymmetry

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-01-04.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited core scientific claims and mechanisms described in the transcript: PCM1 association with centrosome age, Dld endosome polarization, Par-3/dynein loading on recycling endosomes, Rab5b→Rab11a maturation, cross-species conservation in hiPSC-derived neural progenitors, and clonal division outcomes.
- transcript topics: Asymmetric localization of PCM1 at the posterior mother centrosome (Cep83+); Delta-like endosome (Dld) polarization and Notch signaling asymmetry; Co-localization and interaction of Par-3 and dynein on recycling endosomes; Rab5b to Rab11a endosome maturation on Dld endosomes; Conservation of PCM1 asymmetry and endosome dynamics in hiPSC-derived neural progenitors; Clonal analysis of RGP divisions: P/P, P/N, N/N outcomes

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- PCM1 enriched at the posterior mother centrosome Cep83+
- PCM1 localizes to the central zone near Delta-containing endosomes (Dld) and moves with Dld endosomes
- Loss of pcm1 disrupts endosome dynamics and increases neuronal differentiation at the expense of progenitor self-renewal
- PCM1 facilitates the Rab5b to Rab11a transition and promotes Par-3 and dynein assembly on recycling endosomes
- Conserved PCM1–CEP83–RAB11 associations observed in human hiPSC-derived neural progenitors and organoids
- PCM1 acts as a bridge linking centrosome age to polarized endosome trafficking and Notch signaling to preserve progenitor fate

QC result: Pass.

248: Disruption of PIKfyve triggers lysosomal repair and mitochondrial adaptation

Gustavo Barra — Sat, 03 Jan 2026 06:09:00 +0000

Kutchukian C et al., Nature Communications - Disruption of the PIKfyve/Fig4/Vac14 complex drives ULK1-dependent trafficking of PI4KIIα and ATG9A to lysosomes, elevating lysosomal PI(4)P to promote membrane repair and induce mitochondrial fragmentation with increased respiration. Key terms: PIKfyve, PI4KIIα, PI(4)P, ULK1, lysosomal repair.

Study Highlights:
PIKfyve complex disruption or pharmacological inhibition reduces mTORC1 signaling, activating ULK1 and driving ATG9A-dependent trafficking of PI4KIIα from the TGN to lysosomes. PI4KIIα accumulation elevates lysosomal PI(4)P, recruiting OSBP/ORP proteins to transfer cholesterol and phosphatidylserine and enhance lysosomal membrane repair. Elevated lysosomal PI(4)P recruits ORP1L at ER–lysosome–mitochondria three-way contacts, enabling PI(4)P transfer to mitochondria, Drp1 recruitment, mitochondrial fragmentation, and increased oxygen consumption. Inhibition of ULK1 or PI4KIIα or mitochondrial targeting of Sac1 reverses these lysosomal and mitochondrial phenotypes.

Conclusion:
A ULK1-dependent PI4KIIα–PI(4)P pathway links PIKfyve complex dysfunction to coordinated lysosomal membrane repair and adaptive mitochondrial remodeling

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Disruption of the PIKfyve complex unveils an adaptive mechanism to promote lysosomal repair and mitochondrial homeostasis

First author:
Kutchukian C

Journal:
Nature Communications

DOI:
10.1038/s41467-025-65798-6

Reference:
Kutchukian C., Casas M., Dixon R. E., Dickson E. J. Disruption of the PIKfyve complex unveils an adaptive mechanism to promote lysosomal repair and mitochondrial homeostasis. Nature Communications. 2025;16:10761. https://doi.org/10.1038/s41467-025-65798-6

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/pikfyve-lysosome-mitochondria

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-01-03.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript's coverage of the paper's mechanism: acute PIKfyve disruption activates a ULK1-dependent PI4KIIα/ATG9A trafficking program, increases lysosomal PI(4)P, recruits OSBP/ORP proteins for membrane repair, enhances ER–lysosome–mitochondria three-way contacts with ORP1L and Drp1-driven mitochondrial fra
- transcript topics: ULK1-dependent trafficking of PI4KIIα and ATG9A from the TGN to lysosomes; PI(4)P redistribution to lysosomes and PI4KIIα relocation from the TGN; OSBP/ORP-mediated lipid transfer and lysosomal membrane repair (PITT pathway); ER–lysosome–mitochondria three-way contact sites and ORP1L/Drp1 recruitment; Mitochondrial fragmentation and enhanced respiration (Seahorse data); ULK1/mTOR signaling modulation

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Acute PIKfyve inhibition reduces mTORC1 signaling and ULK1 activation
- ULK1-dependent trafficking of PI4KIIα and ATG9A from the TGN to lysosomes
- PI(4)P redistribution to lysosomes via PI4KIIα relocation to lysosomes
- OSBP/ORP-mediated transfer of cholesterol and phosphatidylserine to lysosomal membranes (PITT pathway)
- ULK1-dependent recruitment of ORP1L at ER–lysosome–mitochondria three-way contacts and DRP1 recruitment
- PI(4)P-dependent lysosomal membrane repair and enhanced mitochondrial respiration

QC result: Pass.

247: Genome graphs reveal structural variation in M. tuberculosis

Gustavo Barra — Fri, 02 Jan 2026 13:08:39 +0000

Canalda-Baltrons A et al., Nature Communications - Long-read assemblies and a pangenome reference graph uncover widespread structural variants that shape Mycobacterium tuberculosis evolution and contribute to drug resistance. Key terms: structural variation, pangenome graph, Mycobacterium tuberculosis, drug resistance, long-read sequencing.

Study Highlights:
The authors built an M. tuberculosis pangenome reference graph from 859 high-quality long-read assemblies and identified 3,077 unique structural variants genome-wide. They developed miniwalk to genotype SVs from graph-mapped assemblies and showed higher precision for short-read SV genotyping (0.7 vs 0.46 for manta) at modest cost to recall. SVs cluster in GC-rich PE/PPE regions and include recurrent events such as a ppe25-ppe27 deletion fixed in L4.4 and diverse deletions of the copper exporter ctpV specific to sub-lineage L1.2.1 that alter copper-associated transcription. Genotyping 41,134 isolates revealed non-canonical SVs and SV-gene burdens associated with resistance to multiple first- and second-line drugs

Conclusion:
Structural variants are an important and previously underappreciated driver of M. tuberculosis evolution and drug resistance, and pangenome graph approaches improve their detection

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Genome graphs reveal the importance of structural variation in Mycobacterium tuberculosis evolution and drug resistance

First author:
Canalda-Baltrons A

Journal:
Nature Communications

DOI:
10.1038/s41467-025-65779-9

Reference:
Canalda-Baltrons A., Theys D., Chang X., Viberg L. T., Sherry N. L., Coin L., Dunstan S. J., Silcocks M., Hall M. B. Genome graphs reveal the importance of structural variation in Mycobacterium tuberculosis evolution and drug resistance. Nature Communications. 2025;16:10746. https://doi.org/10.1038/s41467-025-65779-9

License:
CC BY 4.0 International License (CC-BY-4.0)

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/structural-variation-mtb-pangenome

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-01-02.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Substantive auditing of transcript segments describing: PRG construction and miniwalk SV genotyping; genome-wide SV landscape across lineages; ESX loci and ppe25-ppe27 deletion; copper exporter ctpV deletions in L1.2.1 with copper accumulation signals; DR associations across 41,134 isolates; and clinical implications.
- transcript topics: PRG construction and miniwalk SV genotyping; Genome-wide SV landscape across M. tuberculosis lineages; ESX secretion systems SVs and ppe25-ppe27 deletion; Copper homeostasis and ctpV deletions in L1.2.1; SV-based drug resistance associations across 41,134 isolates; Clinical implications and integration into sequencing pipelines

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- PRG built from 859 long-read Mtb assemblies; 821 assemblies used for SV genotyping
- Miniwalk SV genotyping on Illumina data yields precision 0.7 vs manta 0.46
- 3077 unique SVs identified across 821 isolates (1127 INS, 1694 DEL, 59 DUP, 58 INV, 139 CNVs)
- Largest SV ~66,582 bp inverted and translocated in lineage 9
- ppe25-ppe27 deletion in ESX-5 is the most frequent non-reference haplotype (9% overall; fixed in sub-lineage 4.4)
- Loss-of-function deletions of ctpV observed in L1.2.1 with transcriptional signals consistent with copper accumulation

QC result: Pass.

246: SV2A structural pharmacology and allosteric occlusion

Gustavo Barra — Thu, 01 Jan 2026 18:13:00 +0000

Pidathala S et al., Nature Communications - High-resolution cryo-EM structures of human SV2A reveal that orthosteric ligands induce an occluded MFS conformation and a secondary allosteric pocket modulates ligand binding. Key terms: SV2A, allosteric modulation, cryo-EM, levetiracetam, padsevonil.

Study Highlights:
The authors report sub-3 Å cryo-EM structures of human SV2A in the apo state and in complexes with levetiracetam, UCB-J, padsevonil, and the allosteric modulator UCB1244283. Levetiracetam and UCB-J bind the central cavity and drive inward movement of TM1 with Phe188 sealing the lumen, producing complete occlusion with levetiracetam and partial occlusion with UCB-J. UCB1244283 occupies a distinct allosteric site ~13 Å above the orthosteric pocket, reshapes the orthosteric site, lowers UCB-J Kd, increases Bmax, and slows ligand dissociation. Padsevonil binds both orthosteric and allosteric sites, precluding UCB1244283-mediated potentiation and illustrating overlapping but flexible allosteric interactions.

Conclusion:
SV2A uses orthosteric-induced occlusion combined with a secondary allosteric pocket to regulate ligand engagement, offering a structural blueprint for designing SV2A-specific modulators

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Structural pharmacology of SV2A reveals an allosteric modulation mechanism in the major facilitator superfamily

First author:
Pidathala S

Journal:
Nature Communications

DOI:
10.1038/s41467-025-65781-1

Reference:
Pidathala S., Chen X., Dai Y., Gorgulla C., Niu Y., Liu F., Lee C.-H. Structural pharmacology of SV2A reveals an allosteric modulation mechanism in the major facilitator superfamily. Nature Communications. 2025;16:10748. https://doi.org/10.1038/s41467-025-65781-1

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/sv2a-allosteric-occlusion

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-01-01.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited transcript sections describing SV2A mechanism, ligand-induced occlusion, orthosteric vs allosteric ligands, dual-binding Padsevonil, conditional engagement, and implications for MFS transporters; compared to the original article text.
- transcript topics: SV2A as a major facilitator superfamily transporter in brain; Cryo-EM methods and saposin nanoparticle reconstitution for SV2A; Levetiracetam and UCB-J binding to central cavity and induction of occlusion; TM1 inward movement and Phe188 sealing the central cavity; Allosteric site ~13 Å above orthosteric site; UCB1244283 mechanism; Padsevonil dual orthosteric/allosteric binding

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- SV2A is a major facilitator superfamily (MFS) transporter abundantly present in synaptic vesicles
- Sub-3 Å cryo-EM structures reported for SV2A in apo form and ligand-bound states
- Levetiracetam and UCB-J bind the central cavity and induce occlusion; levetiracetam causes complete occlusion, UCB-J partial occlusion
- UCB1244283 binds an allosteric site ~13 Å above the orthosteric site and stabilizes the occluded state while slowing ligand dissociation
- Padsevonil occupies both orthosteric and allosteric sites (dual binder)
- Allosteric modulation can be conditional, requiring orthosteric occupancy (conditional engagement)

QC result: Pass.

245: Benchmarking DNA foundation models

Gustavo Barra — Wed, 31 Dec 2025 17:12:59 +0000

Feng H et al., Nat Commun - A comprehensive, unbiased benchmark compares five DNA foundation models across 57 datasets and multiple tasks, finding mean token embeddings improve classification and that model strengths vary by task and pre-training. Key terms: DNA foundation models, mean token embedding, sequence classification, variant effect, gene expression.

Study Highlights:
The study evaluated DNABERT-2, NT-v2, HyenaDNA, Caduceus-Ph, and GROVER on 57 datasets spanning sequence classification, gene expression prediction, variant effect quantification, and TAD recognition. Mean token embedding consistently and significantly outperformed summary-token and max pooling for sequence classification. Model performance was task-dependent: Caduceus-Ph excelled at human TFBS and promoter tasks, NT-v2 led pathogenic variant identification, HyenaDNA scaled efficiently and benefited from multi-species pre-training, while specialized models outperformed general foundations on QTL prediction. Zero-shot embeddings provided modest gene expression prediction and NT-v2 attention patterns did not reveal inherent TAD recognition.

Conclusion:
Mean token pooling yields more robust sequence-level representations and model choice should align with task, input length, and pre-training data for best genomic performance

Music:
Enjoy the music based on this article at the end of the episode.

First author:
Feng H

Journal:
Nat Commun

DOI:
10.1038/s41467-025-65823-8

Reference:
Feng H, Wu L, Zhao B, Huff C, Zhang J, Wu J, Lin L, Wei P & Wu C. Benchmarking DNA foundation models for genomic and genetic tasks. Nat Commun. 2025;16:10780. https://doi.org/10.1038/s41467-025-65823-8

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/dna-foundation-models-benchmark

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-12-31.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript's coverage of core scientific claims: DNA foundation models benchmarking, pooling strategies (mean token embedding), zero-shot embeddings with a downstream classifier, VEQ dichotomy, multispecies pre-training and cross-species generalization, long-sequence performance, TAD recognition limitations
- transcript topics: DNA foundation models and zero-shot embeddings; Pooling strategies for sequence representations (mean token embedding vs summary/max pooling); Downstream classification using zero-shot embeddings (random forest); Variant effect quantification: pathogenic vs QTL (VEQ dichotomy); Multispecies pre-training and cross-species generalization; Cross-species transfer in promoter identification (Arabidopsis example)

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Mean token embedding consistently improves sequence classification across all foundation models and yields measurable AUROC gains.
- Zero-shot embeddings with frozen weights are evaluated with a downstream random forest classifier to measure embedding quality without fine-tuning.
- VEQ dichotomy: generalists excel at pathogenic variant identification; specialized models excel at tissue-specific QTL predictions.
- Multispecies pre-training improves generalization; 14 of 49 tasks show statistically significant improvements, with some tasks favoring human-only pre-training.
- Cross-species transfer evidence: HyenaDNA pre-trained on human genomes shows cross-species transfer advantages (e.g., Arabidopsis promoter identification).
- NT-v2 self-attention does not inherently recognize higher-order chromatin structures (TADs) in zero-shot mode.

QC result: Pass.

244: NEK7 couples SDHB to preserve mitochondrial electron transport and limit liver fibrosis

Gustavo Barra — Tue, 30 Dec 2025 05:57:16 +0000

Sun Z et al., Nature Communications - Mitochondrial NEK7 is imported via MTS peptides, binds SDHB to stabilize complex II conformation, prevent reverse electron transport and ROS, and thereby protects against spontaneous and experimentally induced liver fibrosis. Key terms: NEK7, SDHB, reverse electron transport, ROS, liver fibrosis.

Study Highlights:
NEK7 localizes to hepatocyte mitochondria through two internal mitochondrial targeting signal peptides and co‑localizes with SDHB. NEK7 binds SDHB and stabilizes complex II spatial conformation without changing SDHB abundance or complex assembly. Hepatocyte NEK7 deficiency induces reverse electron transport, increases mitochondrial membrane potential and mtROS, suppresses respiration, and triggers spontaneous liver fibrosis while worsening CCl4‑induced fibrosis. RET inhibitors or NEK7 overexpression restore mitochondrial function and substantially attenuate CCl4‑ and CDAHFD‑induced liver fibrosis.

Conclusion:
NEK7 maintains respiratory chain electron transport homeostasis via SDHB binding and is a candidate therapeutic target to prevent or treat liver fibrosis

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
NEK7 couples SDHB to orchestrate respiratory chain electron transport homeostasis that impedes liver fibrosis

First author:
Sun Z

Journal:
Nature Communications

DOI:
10.1038/s41467-025-65790-0

Reference:
Sun Z., Le S., Hua H., Ren Y., Zhu W., Wang X., Gu W., Huang S., Zhong D., Sun Y., Zhang Y., Zhang A. & Jia Z. NEK7 couples SDHB to orchestrate respiratory chain electron transport homeostasis that impedes liver fibrosis. Nature Communications. 2025;16:10751. https://doi.org/10.1038/s41467-025-65790-0

License:
CC BY 4.0 / Creative Commons Attribution 4.0 International License

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/nek7-sdhb-mitochondria-fibrosis

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-12-30.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the spoken content for core mechanistic claims and experimental outcomes: mitochondrial localization of NEK7 via MTS, NEK7–SDHB binding and complex II stabilization, consequences of NEK7 deficiency (RET, mtROS, membrane potential, respiration), fibrosis phenotypes in hepatocyte NEK7 knockout mice, rescue by NEK
- transcript topics: NEK7 mitochondrial localization and mitochondrial targeting sequences (MTS); NEK7–SDHB interaction and stabilization of mitochondrial complex II; NEK7 deficiency effects: RET, mtROS, membrane potential, respiration impairment; Spontaneous liver fibrosis in hepatocyte NEK7 knockout mice; NEK7 overexpression mitigates CCl4- and CDAHFD-induced liver fibrosis; RET inhibitors and ROS scavengers mitigate NEK7-deficiency–driven fibrosis

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- NEK7 localizes to mitochondria in hepatocytes via two mitochondrial targeting signal peptides (MTS).
- NEK7 directly binds SDHB and stabilizes the spatial conformation of complex II, supporting forward electron transport.
- NEK7 deficiency in hepatocytes induces RET, increases mtROS, increases membrane potential, reduces respiration, and leads to spontaneous liver fibrosis.
- Overexpression of NEK7 reduces liver fibrosis in both CCl4- and CDAHFD-induced models and restores mitochondrial morphology/function.
- NEK7’s protective effect is independent of NLRP3 inflammasome activation in hepatocytes.
- RET inhibitors and ROS scavengers alleviate NEK7 deficiency–driven fibrosis in vivo and in vitro.

QC result: Pass.

243: Genome-wide UVB GxE study finds 162 vitamin D variants

Gustavo Barra — Mon, 29 Dec 2025 05:54:17 +0000

Shraim R et al., Nat Commun - A GWIS of 338,977 UK Biobank White British participants using a cumulative weighted ambient UVB measure identified 307 independent loci for 25-hydroxyvitamin D, including 162 novel variants. Key terms: vitamin D, gene-environment interaction, ambient UVB, GWAS, circadian rhythm.

Study Highlights:
The study linked a cumulative and weighted ambient UVB (CW-D-UVB) dose from TEMIS to each participant’s residence and blood draw date to model gene-environment interaction on standardized log-transformed 25OHD in 338,977 White British UK Biobank participants. Genome-wide marginal, interaction, and joint tests identified 307 independent variants associated with 25OHD, 162 of which were novel to prior GWAS. SNP-heritability increased across CW-D-UVB quintiles from 8.48% in the lowest to 15.56% in the highest and was higher in participants reporting ≥3 hours outdoors. Functional annotation implicated known vitamin D genes, glucuronidation and lipid metabolism pathways, and circadian clock genes including BMAL1 and NPAS2, with replication showing concordant effect directions in European, LURIC, and ORCADES cohorts

Conclusion:
Incorporating a precise ambient UVB exposure measure increased power to detect genetic effects on vitamin D status and revealed GxE interactions linking vitamin D biology with lipid metabolism and circadian regulation

Music:
Enjoy the music based on this article at the end of the episode.

First author:
Shraim R

Journal:
Nat Commun

DOI:
10.1038/s41467-025-65820-x

Reference:
Shraim R, Timofeeva M, Wyse C, van Geffen J, van Weele M, Romero-Ortuno R, Lopez LM, Pilz S, März W, Fletcher BS, Kleber ME, Wilson JF, Theodoratou E, Dunlop MG, McManus R, Zgaga L. Genome-wide gene-environment interaction study uncovers 162 vitamin D status variants using a precise ambient UVB measure. Nat Commun. 2025;16:10774. https://doi.org/10.1038/s41467-025-65820-x

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/uvb-gxe-vitamin-d-variants

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-12-29.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript's coverage of: (i) construction of the CW-D-UVB exposure metric and study scale; (ii) genome-wide and interaction results for 25OHD; (iii) heritability gradient with UVB; (iv) key genes and pathways (circadian clock, UGT glucuronidation, lipid metabolism); (v) replication across European UKB, LUR
- transcript topics: CW-D-UVB environmental exposure measurement; GWAS results for 25OHD (marginal, interaction, joint tests); Gene-environment interactions with UVB; SNP-based heritability gradient across UVB quintiles; Circadian clock genes BMAL1/ARNTL and NPAS2; UGT glucuronidation and lipid metabolism pathways

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- CW-D-UVB: cumulative, weighted ambient UVB dose over 135 days prior to sampling
- Cohort: 338,977 UK Biobank participants of White British ancestry
- Identified 307 independent 25OHD variants; 162 novel variants
- SNP-based heritability (h2SNP) increases with ambient UVB: 8.48% in CW-D-UVB Q1 vs 15.56% in Q5; outdoors ≥3h: 11.01%
- 20 variants show GxE interaction with UVB exposure; novel interaction at COPB1 and PSMA1; circadian clock genes BMAL1/ARNTL and NPAS2 implicated
- Functional annotation: enrichment in lipid metabolism pathways and glucuronidation; liver-tissue enrichment

QC result: Pass.

242: AAV9-fcMISv2 gene therapy prevents pregnancy in female cats

Gustavo Barra — Sun, 28 Dec 2025 08:35:31 +0000

Godin P et al., Nature Communications - A single intramuscular injection of an AAV9 vector encoding feline anti‑Müllerian hormone (fcMISv2) in prepubertal kittens produced sustained supraphysiological AMH, was well tolerated, and prevented breeding‑induced ovulation and pregnancy in adult females. Key terms: gene therapy, anti-Müllerian hormone, feline sterilization, adeno-associated virus, population control.

Study Highlights:
Twelve 2–3 month-old kittens received a single IM dose of AAV9-fcMISv2 (low or high dose) or empty AAV9 and were monitored for up to 21 months for females and 10 months for males. Treated animals showed rapid viral clearance, no clinically significant systemic inflammation or growth impairment, and no anti‑AMH antibody response. Females developed sustained elevated AMH, had reduced fecal estrogen and progestogen metabolites, increased circulating LH, lacked luteal phases, displayed altered estrous behavior, and none of the treated females became pregnant during a year-later 4‑month mating trial. Males completed puberty, maintained normal testis development, semen parameters, and in vitro fertilizing capacity, indicating preserved male fertility.

Conclusion:
Prepubertal intramuscular delivery of AAV9-fcMISv2 is a safe, durable, female-specific sterilant in domestic cats that prevents breeding-induced ovulation and pregnancy while sparing male reproductive function

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Gene therapy delivery of anti‑Müllerian hormone in prepubertal female domestic cats induces long-term sterilization.

First author:
Godin P

Journal:
Nature Communications

DOI:
10.1038/s41467-025-65780-2

Reference:
Godin P., Nagykery N., Sicher N., Barnes J. L., Miller A. G., Bunner C., Thompson A. K., Kano M., Gao G., Wang D., Donahoe P. K., Rhodes L., Brake D. A., Conlon T. J., Swanson W. F., Vansandt L. M. & Pépin D. Gene therapy delivery of anti‑Müllerian hormone in prepubertal female domestic cats induces long-term sterilization. Nat Commun. 2025;16:10747. https://doi.org/10.1038/s41467-025-65780-2

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/aav9-fcmisv2-sterilization-cats

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-12-28.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript portions describing vectored contraception, prepubertal kitten treatment, sustained AMH production, safety in both sexes, mating trial outcomes, hormonal and uterine changes, and observed behavioral aspects.
- transcript topics: Vectored contraception and AMH target; Prepubertal AAV9-fcMISv2 administration in kittens; Safety and immunogenicity in cats; Durable AMH production and pharmacokinetics; Block of ovulation and absence of luteal phases; Mating trial outcomes and pregnancy prevention

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Prepubertal AAV9-fcMISv2 injection yields sustained supraphysiological AMH production and sterilization in female kittens
- Single low- or high-dose intramuscular injection with follow-up up to 21 months in females and ~9–10 months in males
- 100% pregnancy prevention in treated females during a mating trial (no pregnancies in treated group vs controls)
- No anti-AMH antibodies detected in treated cats
- Males show normal puberty, testicular development, and fertility parameters
- Treated females exhibit smaller uterine horn diameters post-puberty, suggesting protective effects

QC result: Pass.

241: Wagyu T2T reveals a cattle X neocentromere

Gustavo Barra — Sat, 27 Dec 2025 09:17:58 +0000

Pineda PS et al., Nature Communications - A telomere-to-telomere Wagyu assembly uncovers a natural neocentromere on the cattle X formed by inverted repeats and transposable element expansion, adds hundreds of new genes, and improves variant discovery. Key terms: cattle genomics, neocentromere, centromere evolution, telomere-to-telomere, structural variants.

Study Highlights:
The UOA_Wagyu_1 haplotype-resolved assembly includes a complete X chromosome and four T2T autosomes, adding 431 Mb relative to the ARS-UCD2.0 reference and annotating 738 new protein-coding genes. The cattle X centromere spans ~12 Mb and is a natural neocentromere composed mainly of highly identical inverted repeats and transposable elements, lacking canonical bovine satellite arrays and showing low CENP-A signal. The BTAX centromere exhibits CpG depletion and elevated TpG consistent with TE expansion followed by methylation and CpG deamination, and all 37 centromeric protein-coding genes are expressed in testes. Using UOA_Wagyu_1_Y increased mapping rates for Wagyu reads and enabled discovery of 49,610 structural variants from 20 animals, revealing Wagyu-specific SV and PAV hotspots overlapping genes enriched for olfactory transduction.

Conclusion:
A breed-specific T2T cattle genome reveals a dynamic, TE-rich X neocentromere with testis-expressed genes and substantially improves structural variant discovery for Wagyu populations

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Insights into natural neocentromere evolution from a cattle T2T X chromosome

First author:
Pineda PS

Journal:
Nature Communications

DOI:
10.1038/s41467-025-65778-w

Reference:
Pineda PS, MacPhillamy C, Ren Y, Chen T, Zhong L, Adelson DL, Dessaix C, Perez-Silva J, Haggerty L, Martin FJ, Bottema CDK, Pitchford WS, Rosen BD, Smith TPL, Low WY. Insights into natural neocentromere evolution from a cattle T2T X chromosome. Nature Communications. 2025;16:10745. https://doi.org/10.1038/s41467-025-65778-w

License:
CC BY 4.0 International License

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/wagyu-t2t-x-neocentromere

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-12-27.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript's core scientific claims as presented in the article, focusing on BTAX assembly, centromere architecture, epigenetics, neocentromere formation, gene content within BTAX, X-Y PAR, and improvements in SV discovery and mapping.
- transcript topics: BTAX assembly and haplotype-resolved X chromosome (UOA_Wagyu_1_Y); BTAX centromere structure: inverted repeats and TE content; absence of bovine satellites; Epigenetic features: CENP-A signal, methylation, CpG/TpG dynamics; Two-step model for neocentromere formation: TE expansion followed by CpG deamination; BTAX centromere gene content: 37 centromere genes, 24 newly identified; testes expression; Wagyu SV discovery and improved mapping rates using the Wagyu reference

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- BTAX centromere is a natural neocentromere located on the cattle X chromosome
- BTAX centromere consists primarily of highly identical inverted repeats and transposable elements
- BTAX centromere lacks bovine satellite repeats
- BTAX centromere exhibits low CENP-A signal and CpG depletion with low methylation relative to TpG dinucleotides
- Two-step model for neocentromere formation: TE expansion followed by CpG deamination
- BTAX contains 37 centromere genes; 24 of these are newly identified; all centromere genes are expressed in testes

QC result: Pass.

240: CYFIP1 controls cortical axon development by modulating calcium

Gustavo Barra — Fri, 26 Dec 2025 06:21:00 +0000

Ricci C et al., Nature Communications - Reduction of CYFIP1 delays callosal axon growth and arborization by lowering intracellular calcium and impairing mitochondrial function. Key terms: cyfip1, axon development, calcium, mitochondria, callosal connectivity.

Study Highlights:
In vivo, Cyfip1+/- mice show delayed callosal axon growth at P5 and reduced axonal branching during P15 arborization that normalizes by P30. Cyfip1+/- cortical neurons have reduced cytosolic and mitochondrial calcium, larger and elongated mitochondria, increased mitochondrial density and motility, and decreased mitochondrial membrane potential and ATP at early stages. CYFIP1 associates with Hu proteins and binds mRNAs encoding Cav alpha-1 subunits (Cacna1c, Cacna1e, Cacna1i), stabilizing those transcripts and maintaining membrane protein levels in developing neurons and axons. Loss of CYFIP1 accelerates decay of these channel mRNAs, leading to reduced Cav protein abundance in axons and lower calcium availability. Restoring intracellular calcium with ionomycin or activating L-type channels (Bay-K-8644, nefiracetam) rescues axonal growth and mitochondrial defects in Cyfip1+/- neurons

Conclusion:
CYFIP1 ensures timely cortical callosal development by stabilizing mRNAs for voltage-gated calcium channel subunits to maintain intracellular calcium and mitochondrial function, and its haploinsufficiency may contribute to connectivity deficits linked to neurodevelopmental disorders

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
CYFIP1 governs the development of cortical axons by modulating calcium availability

First author:
Ricci C

Journal:
Nature Communications

DOI:
10.1038/s41467-025-65801-0

Reference:
Ricci C, Midroit MJ, Caicci F, Achsel T, Domínguez-Iturza N, Bagni C. CYFIP1 governs the development of cortical axons by modulating calcium availability. Nature Communications. 2025;16:10764. https://doi.org/10.1038/s41467-025-65801-0

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/cyfip1-calcium-axon-development

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-12-26.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited transcript segments covering in vivo axon development timing, calcium homeostasis, mitochondrial changes, CYFIP1-Hu interactions with CaV channel subunit mRNAs, and rescue experiments (ionomycin and VGCC agonists).
- transcript topics: CYFIP1 background and 15q11.2 CNVs; CYFIP1 dual roles: WRC actin regulation and translational repression; in vivo IUE and postnatal axon development timing (P5, P15, P30); mitochondrial density, motility, and morphology in Cyfip1+/- axons; intracellular Ca2+ dysregulation and mitochondrial function; CYFIP1 association with Hu proteins and regulation of CaV channel subunit mRNAs (CACNA1C, CACNA1E, CACNA1I)

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- CYFIP1 haploinsufficiency delays callosal axon growth and arborization in vivo with normalization by P30
- Cyfip1+/- cortical axons show reduced cytosolic/axo-plasmic Ca2+ and altered mitochondrial function (density, motility, membrane potential, ATP at early stages)
- CYFIP1 binds and stabilizes mRNA of CaV channel subunits CACNA1C, CACNA1E, CACNA1I via Hu proteins, affecting axonal calcium entry
- CaV channel subunits (CaV1.2 CACNA1C, CaV2.3 CACNA1E, CaV3.3 CACNA1I) are reduced in membrane fractions at DIV3 in Cyfip1+/- neurons; later stages show normalization
- mRNA levels of CACNA1E and CACNA1I are significantly reduced in Cyfip1+/- neurons; CACNA1C shows a non-significant downward trend
- Ionomycin and VGCC agonists Bay-K-8644 and Nefiracetam rescue delayed axonal growth and mitochondrial defects

QC result: Pass.

239: Genomic Adaptations of the Svalbard Reindeer

Gustavo Barra — Thu, 25 Dec 2025 10:33:35 +0000

Genome Biology and Evolution - The Genomic Basis of the Svalbard Reindeer’s Adaptation to an Extreme Arctic Environment

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
The Genomic Basis of the Svalbard Reindeer’s Adaptation to an Extreme Arctic Environment

Journal:
Genome Biology and Evolution

DOI:
10.1093/gbe/evaf160

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-12-25.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript sections describing bottleneck/island colonization, PBS-based selection signals, SNPeff-derived variants, CNVs/structural variation, energy metabolism and fasting adaptations, circadian rhythm and vision adaptations, insulation/morphology (dwarfism), and discussed limitations/future directions.
- transcript topics: Population bottleneck and island colonization; PBS-based selection signals and outliers; SNPeff high- and moderate-impact variants; Copy number variation (CNV) and structural variation; Energy metabolism and fat storage; Leptin signaling and insulin resistance

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Svalbard reindeer originated from a founder population likely fewer than 100 individuals around 7000 years ago.
- 62 reindeer genomes were sequenced, with populations from Svalbard, mainland Norway, mainland Russia, and Novaya Zemlya used for comparison.
- Population Branch Statistic (PBS) identified around 75 outlier regions under selection.
- SNPeff annotated variants yielded 1 high-impact and 54 moderate-impact variants within 44 genes.
- Copy number variation (CNV) analysis identified 124 differentiating CNVs; including 4 deletions and 10 duplications overlapping genes; large deletions (>500 bp) fixed in Svalbard.
- Overall, 150 genomic regions under putative selection were identified; ~120 of these correspond to annotated genes.

QC result: Pass.

Chapters

(00:00:00) - How do animals evolve to survive in the Arctic?
(00:04:09) - How did the Svalbard reindeer evolve so quickly?
(00:09:24) - Adaptation to cold and fat
(00:11:10) - The story of the Svalbard Reindeer
(00:15:41) - Winter Songs for Creatures

238: Germline polymorphisms shape antibody light chain repertoires

Gustavo Barra — Wed, 24 Dec 2025 08:16:59 +0000

Engelbrecht E et al., Nat Commun - Long-read sequencing of IGK and IGL paired with AIRR-seq shows that common germline SNVs, SVs, and alleles drive inter-individual differences in light chain gene usage and CDR3 properties. Key terms: immunoglobulin-kappa, immunoglobulin-lambda, germline-variation, antibody-repertoire, long-read-sequencing.

Study Highlights:
The authors combined targeted long-read genomic sequencing of IGK and IGL in 177 donors with matched AIRR-seq (IGK n=164, IGL n=168) to generate phased SNV, SV, and allele callsets and personalized germline databases. Cis guQTL analysis identified 2,352 variants in the unmutated IGK repertoire linked to usage changes in 21 IGKV and 3 IGKJ genes, and 911 variants in IGL linked to 22 IGLV and 3 IGLJ genes, indicating germline variation affects >70% of light chain genes. Lead variants mapped to intergenic regions, RSSs, coding exons and structural variants, with examples including a premature stop in IGKV2-29, a K50D missense in IGKV1-5, RSS spacer changes in IGLV3-16, and copy-number SVs that alter gene usage. Genetic effects were stronger in the antigen-naïve repertoire, associated with shifts in encoded V/J alleles and CDR3 physicochemical properties, and IGK exhibited larger LD blocks and coordinated multi-gene usage compared with IGL.

Conclusion:
Germline polymorphisms across IGK and IGL establish reproducible baseline differences in light chain gene availability and amino acid composition that likely influence antibody-mediated responses.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Germline polymorphisms in the immunoglobulin kappa and lambda loci underpinning antibody light chain repertoire variability

First author:
Engelbrecht E

Journal:
Nat Commun

DOI:
10.1038/s41467-025-66759-9

Reference:
Engelbrecht E, Rodriguez OL, Lees W, Vanwinkle Z, Shields K, Schultze S, Gibson WS, Smith DR, Jana U, Saha S, Peres A, Yaari G, Smith ML, Watson CT. Germline polymorphisms in the immunoglobulin kappa and lambda loci underpinning antibody light chain repertoire variability. Nat Commun. 2025. https://doi.org/10.1038/s41467-025-66759-9

License:
CC BY 4.0 International License

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/ig-light-chain-variation

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-12-24.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the core scientific narrative describing targeted SMRT sequencing of IGK/IGL loci, creation of personalized germline references, guQTL mapping linking variants to gene usage, variant mechanisms (coding, RSS, CNV), LD architecture differences, CDR3 physicochemical properties, and naive vs. antigen-experienced re
- transcript topics: IGK vs IGL locus architecture and diversity; SMRT long-read sequencing and personalized germline references; guQTL mapping and gene usage in IGK/IGL; Coding variants: IGKV2-29 stop codon; Coding variants: IGKV1-5 K50D; Regulatory variants: RSS spacers (IGLV3-16)

QC Summary:
- factual score: 10/10
- metadata score: 9/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license
- episode_title
- publish_description_text

Factual Items Audited:
- Long-read SMRT sequencing of IGK and IGL across 177 individuals with matched AIRR-seq (IGK n=164, IGL n=168).
- Personalized germline reference maps built for each individual to map expressed repertoires.
- >70% of light chain gene usage variation is explained by germline guQTLs in IGK/IGL.
- Lead variants include IGKV2-29 premature stop codon; IGKV1-5 K50D missense; RSS spacer variants in IGLV3-16; CNVs IGKV1-NL1, IGKV1-D-8, IGLV5-39.
- CDR3 aromaticity and aliphaticity are influenced by germline variants (guQTL-linked effects).
- IGK exhibits larger LD blocks and coordinated multi-gene usage; IGL shows smaller LD blocks and more independent usage.

QC Flagged Items (audited and not fully supported):
- episode_title: not checked against an exact canonical value. Editorial episode title is allowed to differ from article title; not flagged as mismatch.
- publish_description_text: not checked against an exact canonical value. Episode description content was not exhaustively audited for exact wording; treated as metadata beacon.

QC result: Pass.

237: Tracing enteric pathogens in Africa with metagenomics and WGS

Gustavo Barra — Tue, 23 Dec 2025 05:49:06 +0000

Thystrup C et al., Nat Commun (2025) - This study combines whole-genome sequencing and metagenomics to map the diversity, abundance, and genomic relationships of enteric foodborne pathogens across human, animal, food and environmental samples in four African LMICs. Key terms: metagenomics, whole-genome sequencing, foodborne pathogens, one-health, surveillance.

Study Highlights:
The project sampled 3,417 items across Ethiopia, Mozambique, Nigeria and Tanzania between 2019 and 2023 and applied culture-based WGS and metagenomic sequencing. Of 446 recovered isolates, 380 high-quality genomes were analyzed (207 E. coli, 138 Salmonella spp., 24 Campylobacter spp., 11 Shigella spp.), and 139 metagenomes passed QC for community profiling. Pathogen distributions were geographically stable over time, with genomic clustering showing closely related isolates across distinct sources consistent with potential transmission routes. Metagenomics revealed dominant genera such as Escherichia, Enterococcus and Bifidobacterium, recovered 13 high-quality MAGs (12 E. coli, 1 Campylobacter), and provided complementary population-level insights though MAGs rarely reached strain-level identity with cultured isolates.

Conclusion:
Combining targeted environmental and food-chain sampling with WGS and metagenomic sequencing strengthens surveillance and source-tracing of foodborne enteric pathogens in resource-limited African settings

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Using metagenomics and whole-genome sequencing to characterize enteric pathogens across various sources in Africa

First author:
Thystrup C

Journal:
Nat Commun (2025)

DOI:
10.1038/s41467-025-66400-9

Reference:
Thystrup C, Gobena T, Salvador EM, Fayemi OE, Kumburu H, Buys EM, Gichure J, Moiane BT, Belina D, Hugho EA, Faife S, Ogunbiyi TS, Akanni G, Ayolabi CI, Mmbaga B, Thomas KM, Pires SM, Njage PMK, Hald T. Using metagenomics and whole-genome sequencing to characterize enteric pathogens across various sources in Africa. Nat Commun (2025). https://doi.org/10.1038/s41467-025-66400-9

License:
CC BY 4.0 International License (CC BY 4.0)

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/metagenomics-wgs-africa

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-12-23.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript’s discussion of study design (WGS vs metagenomics), multicountry sampling, major pathogen findings (E. coli, Salmonella, Campylobacter, Shigella), STs (ST131, ST38, ST1208), MAGs and their concordance with culture data, temporal sewage trends (2021), and limitations (database bias, AMR on plasmid
- transcript topics: WGS vs metagenomics methodological comparison; FOCAL project sampling across four African LMICs; Pathogen diversity across human, animal, food, and environmental reservoirs; E. coli typing (ST131, ST38) and Salmonella typing (ST1208); MAGs and culture-independent surveillance; Temporal trends in sewage pathogen burden (2021 spike)

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- 3,417 samples collected from 24 sources across four African LMICs (Ethiopia, Nigeria, Mozambique, Tanzania).
- 446 bacterial isolates recovered; 380 high-quality genomes subjected to downstream analyses.
- 168 metagenomic samples collected; 139 metagenomic samples passed quality control and were analyzed.
- 13 high-quality MAGs recovered (12 Escherichia coli and 1 Campylobacter).
- E. coli ST131 and ST38 detected across multiple countries/sources; Salmonella ST1208 identified as dominant lineage.
- Temporal sewage data show a notable increase in total FBD pathogen burden in 2021, temporally aligned with the COVID-19 pandemic.

QC result: Pass.

236: XPD translocation and genetic disease etiology

Gustavo Barra — Mon, 22 Dec 2025 05:31:38 +0000

Paul T et al., Nat Commun - Computational modeling reveals how ATP-driven conformational cycles of the XPD helicase drive directional 5′→3′ translocation on single-stranded DNA and how mutations disrupt this process to cause disease. Key terms: XPD, DinG, ssDNA translocation, nucleotide excision repair, disease mutations.

Study Highlights:
The authors combined molecular dynamics, partial nudged elastic band path optimization, transition path sampling, and Markov state modeling to map seven metastable on-path states that define XPD’s ATPase cycle. ATP binding and hydrolysis drive reciprocal rotations of the RecA2 and Arch domains, transmitted via a spring helix and spindle helix, that alternate DNA affinity at two defined constrictions at the 5′ and 3′ ends of the DNA-binding groove. Translocation proceeds in two phases: RecA2-driven sliding of ssDNA through Constriction 1 followed by ATP hydrolysis, constriction switching and sliding through Constriction 2, advancing one nucleotide per ATP. Mapping of missense mutations shows clustering of disease-associated residues at DNA- and ATP-binding sites and classifies mutations that impair DNA binding, ATPase function, or allosteric domain dynamics

Conclusion:
A detailed mechanistic map links XPD’s nucleotide-dependent conformational switching to directional ssDNA translocation and explains how perturbations of key residues underlie XP, CS, and TTD phenotypes

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Translocation mechanism of xeroderma pigmentosum group D protein on single-stranded DNA and genetic disease etiology

First author:
Paul T

Journal:
Nat Commun

DOI:
10.1038/s41467-025-66834-1

Reference:
Paul T, Yan C, Derdeyn-Blackwell G, Ivanov I. Translocation mechanism of xeroderma pigmentosum group D protein on single-stranded DNA and genetic disease etiology. Nat Commun. 2025. https://doi.org/10.1038/s41467-025-66834-1

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/xpd-translocation-disease-etiology

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-12-22.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited transcript portions describing XPD’s translocation mechanism, the seven-state ATPase cycle (S1–S7), the roles of Constriction 1 and Constriction 2, mutation class mapping to XP/CS/TTD phenotypes, XPD–DinG comparison, and per-nucleotide kinetic estimates.
- transcript topics: XPD function in nucleotide excision repair and lesion verification; XPD domain architecture and DNA-binding groove; Seven-state ATPase cycle (S1–S7) and translocation on ssDNA; Constriction 1 (5′ end) and Constriction 2 (3′ end) as molecular clamps; ATP binding/hydrolysis and mechanical coupling (spring spindle helix, Arch/Fe–S interactions); Disease mutations: XP, CS, TTD phenotypes and class mapping

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- XPD translocates 5′→3′ on ssDNA via a seven-state ATPase cycle (S1–S7).
- Two constrictions (Constriction 1 at the 5′ end and Constriction 2 at the 3′ end) act as molecular clamps enabling directional translocation.
- Mutations cluster at DNA-binding and ATPase sites and are categorized into three classes (A XP, B XP/CS, C XP/CS) with disease phenotypes XP, CS, and TTD.
- Key structural elements such as the spring helix and spindle helix couple motor-domain movements to Arch/Fe–S domains.
- XPD and DinG share a common architecture but differ in Fe–S domain anchoring; DinG lacks the XPD-specific anchoring element and shows different intermediate states (SD1–SD5).
- Per-nucleotide translocation times are predicted to be ~4 ms for XPD and ~9 ms for DinG; experimental rates on duplex DNA under load can be ~100 ms per nucleotide.

QC result: Pass.

235: Maternal H3K9 methyltransferases control aRMAE in C. elegans

Gustavo Barra — Sun, 21 Dec 2025 09:54:11 +0000

Sands et al., Nature Communications - Using dual-color reporters in C. elegans, the study shows maternal H3K9 methyltransferases MET-2 and SET-25 antagonistically regulate autosomal random monoallelic expression initiated in the early embryo. Key terms: histone-methyltransferase, aRMAE, MET-2, SET-25, c-elegans.

Study Highlights:
Dual-color fluorescent reporter alleles in C. elegans intestine cells enabled single-cell quantification of allele expression and a targeted screen for aRMAE regulators. MET-2/SETDB1, with LIN-65 and ARLE-14, acts maternally in the 8-cell E-cell to prevent monoallelic expression, while SET-25/SUV39 with HPL-2 and LIN-61 promotes allele silencing. Catalytic SET domains of both MET-2 and SET-25 are required for their opposing activities, and loss of MET-2 increases persistent but non-heritable monoallelic expression whereas loss of SET-25 causes biallelic expression. Reciprocal crosses and genetic interactions indicate these maternal H3K9 HMTs set early embryonic histone states that are propagated through somatic divisions to shape tissue-wide allele expression.

Conclusion:
Maternal MET-2 and SET-25 establish competing H3K9-related chromatin states in the early embryo that bias autosomal alleles toward persistent somatic monoallelic or biallelic expression

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Maternal histone methyltransferases antagonistically regulate autosomal random monoallelic expression (aRMAE) in C. elegans

First author:
Sands

Journal:
Nature Communications

DOI:
10.1038/s41467-025-66501-5

Reference:
Sands, B., Yun, S.R., Oshima, J. et al. Maternal histone methyltransferases antagonistically regulate autosomal random monoallelic expression (aRMAE) in C. elegans. Nat Commun (2025). https://doi.org/10.1038/s41467-025-66501-5

License:
CC BY 4.0 International License

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/maternal-h3k9-armae-c-elegans

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-12-21.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited transcript sections describing MAE basics, the C. elegans reporter MAE assay, intrinsic noise as a MAE metric, the MET-2/SET-25 antagonism and cofactors, maternal deposition in the E-cell, catalytic SET-domain requirements, cross experiments, gene specificity, and translational implications.
- transcript topics: Introduction to autosomal random monoallelic expression (aRMAE); C. elegans MAE reporter system with dual-color alleles (hsp-90); Intrinsic noise as a quantitative MAE measure; RNAi screen identifying H3K9 methyltransferases MET-2 and SET-25; Antagonistic roles of MET-2 (negative regulator) and SET-25 (positive regulator) of MAE; Cofactors LIN-65, ARLE-14, HPL-2, LIN-61

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Autosomal random monoallelic expression (aRMAE) is probabilistic, persistent within a tissue, but not heritable across generations.
- In C. elegans intestine, maternal MET-2 antagonizes SET-25 to regulate MAE; MET-2 promotes biallelic expression while SET-25 promotes monoallelic expression.
- Catalytic SET domains of MET-2 and SET-25 are required for their regulatory effects on MAE.
- Maternal MET-2 and SET-25 act in the E-cell of the 8-cell embryo to regulate MAE; the decision is propagated through somatic divisions but is not heritable.
- Cofactors LIN-65 and ARLE-14 support MET-2; HPL-2 and LIN-61 support SET-25 function.
- MAE regulation is gene-specific; not all MAE-prone genes respond similarly to MET-2 perturbation (e.g., hsp-90 vs vit-2).

QC result: Pass.

234: MTHFR genotype and methionine metabolism predict COVID-19 severity

Gustavo Barra — Sat, 20 Dec 2025 08:43:58 +0000

Petrova B et al., Proc Natl Acad Sci U S A - IMPACC longitudinal metabolomics and genomics analyses show that disruptions in one‑carbon/methionine metabolism together with MTHFR C677T genotype at hospital admission improve prediction of severe COVID‑19 and long COVID risk. Key terms: mthfr, one-carbon metabolism, methionine, metabolomics, long covid.

Study Highlights:
IMPACC profiled plasma metabolites (global and targeted) from over 1,000 hospitalized COVID-19 patients and identified early alterations in one‑carbon metabolism, with emphasis on the methionine cycle. Methionine‑sulfoxide and S‑adenosylhomocysteine (SAH) were elevated in patients with more severe clinical trajectories and changed over serial visits. The common hypomorphic MTHFR C677T (AA) genotype associated with distinct methionine‑cycle metabolite profiles and, when combined with baseline methionine, methionine‑sulfoxide, and SAH levels, significantly improved mortality prediction versus genotype alone. The combined genotype–metabolite factor also stratified risk of long COVID across patient‑reported outcome clusters.

Conclusion:
Integrating MTHFR C677T status with early plasma methionine‑cycle metabolite measurements can enhance early risk stratification for severe COVID‑19 and long COVID.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
MTHFR allele and one-carbon metabolic profile predict severity of COVID-19

First author:
Petrova B

Journal:
Proc Natl Acad Sci U S A

DOI:
10.1073/pnas.2509118122

Reference:
Petrova B, Syphur C, Montgomery RR, Levy O, Diray‑Arce J, Kleinstein SH, Kanarek N, Culhane AJ, Chen J, et al. MTHFR allele and one‑carbon metabolic profile predict severity of COVID‑19. Proc Natl Acad Sci U S A. 2025;122(51):e2509118122. https://doi.org/10.1073/pnas.2509118122

License:
CC BY 4.0 International License (CC BY 4.0)

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/mthfr-methionine-covid-risk

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-12-20.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited substantive scientific content in the transcript: one-carbon metabolism and methionine cycle; MTHFR C677T polymorphism; IMPACC cohort design with visit-1 sampling within 72 hours; early metabolite perturbations (methionine, methionine sulfoxide, SAH, glycine, serine); two-hit hypothesis; predictive modeling (AI
- transcript topics: One-carbon metabolism and the methionine cycle; MTHFR C677T polymorphism and AA homozygosity; IMPACC cohort design and visit-1 sampling within 72 hours; Early metabolite changes: methionine, methionine sulfoxide, SAH, glycine, serine; Long COVID risk and trajectory analyses; Two-hit hypothesis and predictive modeling (AIC)

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Combined MTHFR AA genotype with acute methionine-cycle metabolite levels (SAH, methionine, methionine sulfoxide) improves prediction of mortality and long COVID risk
- Visit 1 samples were collected within 72 hours of hospital admission
- SAH and methionine sulfoxide levels are elevated with higher disease severity; glycine and serine changes observed in relation to severity
- MTHFR C677T AA allele frequency in IMPACC is 13.3% (AA allele), with ~10–15% globally for the AA variant
- AIC-based model comparison shows substantial improvement when adding MTHFR genotype and methionine-cycle metabolites to clinical data (AIC ~790.85 -> ~738.66; χ2(3)=58.2, P<0.001)
- Long COVID risk is predicted by combining MTHFR allele status with early one-carbon metabolite changes

QC result: Pass.

233: NuA3 structure reveals the mechanism of H3K14 acetylation

Gustavo Barra — Fri, 19 Dec 2025 07:02:26 +0000

Shi W et al., Mechanistic insights into histone recognition and H3K14 acetylation by the NuA3 histone acetyltransferase complex - Cryo-EM structures of the yeast NuA3 complex show a composite histone tail binding cleft formed by Sas3 and Nto1 that dictates selective acetylation of H3K14. Key terms: NuA3, Sas3, Nto1, H3K14 acetylation, cryo-EM.

Study Highlights:
The six-subunit NuA3 complex was purified and shown to acetylate H3K14 preferentially on H3K4- or H3K36-trimethylated substrates. Cryo-EM maps of the apo, acetyl-CoA-bound, and acetyl-CoA plus H3 tail-bound states were determined at 3.7 Å, 3.1 Å, and 3.2 Å resolution, respectively. The H3 tail binding cleft is formed cooperatively by the catalytic Sas3 MYST domain and the Nto1 PZP region, with a hydrophobic pocket engaging H3 residues 9–12 and a network of polar contacts around Gly13–Ala15 that confer site specificity. Mutations predicted to disrupt contacts (L369R, N354A, E452Q) impair or abolish HAT activity in vitro and reduce H3K14 acetylation in yeast. Binding of acetyl-CoA induces conformational shifts in a histone-engaging loop and a CoA-engaging helix that likely position catalytic residues for transfer

Conclusion:
The structures define how cooperative recognition by Sas3 and Nto1 and local conformational changes confer high specificity for H3K14 acetylation and suggest conservation of this recognition mode in human homologs

Music:
Enjoy the music based on this article at the end of the episode.

First author:
Shi W

Journal:
Mechanistic insights into histone recognition and H3K14 acetylation by the NuA3 histone acetyltransferase complex

DOI:
10.1038/s41467-025-67049-0

Reference:
Shi W., Zhao L., Wang Y., Zhang Y., Liu S., Wang Y., Kornberg R. D., Zhang H. Mechanistic insights into histone recognition and H3K14 acetylation by the NuA3 histone acetyltransferase complex. Nat Commun (2025). https://doi.org/10.1038/s41467-025-67049-0

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/nua3-h3k14-structure

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-12-19.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript's coverage of NuA3 structure-function findings: complex composition, cooperative histone tail binding cleft, acetyl-CoA–induced conformational priming, substrate specificity with Gly13, mutational evidence (L369R, N354A, E452Q), recruitment marks (H3K4me3/H3K36me3), and cross-species conservation
- transcript topics: NuA3 subunit composition; Cooperative H3 tail binding cleft formed by Sas3 and Nto1; Acetyl-CoA binding and conformational priming; Substrate specificity and Gly13 determinant; Mutational effects: L369R, N354A, E452Q; Recruitment marks: H3K4me3 and H3K36me3

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- NuA3 is a six-subunit histone acetyltransferase complex (Sas3, Nto1, Yng1, Eaf6, Taf14, Pdp3).
- NuA3 acetylates histone H3K14 and recruitment depends on pre-existing marks H3K4me3 and H3K36me3.
- A deep histone tail binding cleft is formed cooperatively by Sas3 and Nto1, yielding site specificity for H3K14.
- Acetyl-CoA binding to Sas3 primes the complex by repositioning the histone-engaging loop and the CoA-engaging helix to facilitate tail docking.
- Gly13 preceding K14 acts as a critical determinant; G13R mutation reduces or abolishes HAT activity.
- Mutations L369R and N354A disrupt histone-tail interactions; E452Q abolishes catalytic activity.

QC result: Pass.

232: Lamin A/C steers fork restart via H3K9me3 and PARylation

Gustavo Barra — Thu, 18 Dec 2025 07:38:27 +0000

Cherdyntseva V et al., Nat Commun - Nucleoplasmic Lamin A/C, together with LAP2α, enforces active replication fork slowing during mild replication stress by promoting local H3K9me3 and ADP-ribosylation to restrain RECQ1-mediated restart and protect genome stability. Key terms: Lamin A/C, replication fork, H3K9me3, PARylation, RECQ1.

Study Highlights:
Lamin A/C dynamically associates with replication factories throughout the nucleus and its acute depletion abolishes stress-induced fork slowing and increases chromosomal breakage. Loss of nucleoplasmic Lamin A/C or LAP2α reduces poly-ADP-ribosylation (PAR) at nascent DNA, leading to untimely RECQ1-dependent restart of reversed forks. Mild replication stress induces accumulation of H3K9me3 at replication forks, and Lamin A/C is required to maintain this mark by preventing its removal by the demethylase KDM3A/JMJD1A. Inhibiting G9a to prevent H3K9 methylation phenocopies Lamin A/C loss, reducing PAR at forks and deregulating RECQ1 restart, whereas PARG inhibition or KDM3A downregulation restores PAR levels and fork slowing.

Conclusion:
Nucleoplasmic Lamin A/C maintains local chromatin compaction and PARylation at replication factories to limit RECQ1 activity, enforce fork slowing under mild stress, and preserve genome stability

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Nucleoplasmic Lamin A/C controls replication fork restart upon stress by modulating local H3K9me3 and ADP-ribosylation levels

First author:
Cherdyntseva V

Journal:
Nat Commun

DOI:
10.1038/s41467-025-66098-9

Reference:
Cherdyntseva V, Paulson J, González-Acosta D, Ubieto-Capella P, Rodrigues M, Aouami M, Adakli S, Gagné J-P, Bakker C, Poirier GG, Taneja N, Lopes M. Nucleoplasmic Lamin A/C controls replication fork restart upon stress by modulating local H3K9me3 and ADP-ribosylation levels. Nat Commun. 2025. https://doi.org/10.1038/s41467-025-66098-9

License:
CC BY 4.0 / Creative Commons Attribution 4.0 International License

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/nucleoplasmic-lamin-fork-restart

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-12-18.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript’s substantive coverage of the Lamin A/C–H3K9me3–PAR axis controlling fork slowdown and RECQ1 restart under mild replication stress, including roles of LAP2α, G9a, KDM3A, and ChromStretch mapping.
- transcript topics: Lamin A/C dynamic interaction with replication factories; Acute Lamin A/C depletion and LAP2α effect on fork slowing; RECQ1-mediated fork restart and genetic rescue by RECQ1 depletion; Local PARylation at replication forks and Lamin A/C control; H3K9me3 accumulation at forks and maintenance by Lamin A/C via KDM3A; G9a-driven chromatin methylation and chromatin compaction

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Lamin A/C dynamically interacts with replication factories throughout the nucleus
- Acute Lamin A/C depletion abolishes active fork slowing under mild replication stress; LAP2α depletion yields a similar phenotype
- RECQ1 restart contributes to fork restart; RECQ1 depletion rescues slowed forks
- PARylation levels at replication forks are locally reduced after Lamin A/C loss and can be restored by PARG inhibition
- H3K9me3 accumulates at replication forks under mild replication stress and Lamin A/C maintains this mark by inhibiting the demethylase JMJD1A/KDM3A
- G9a inhibition phenocopies Lamin A/C loss, reducing PAR at forks and deregulating RECQ1 restart; PARG inhibition can rescue

QC result: Pass.

231: Transcription start sites as a germline mutational hotspot

Gustavo Barra — Wed, 17 Dec 2025 12:40:33 +0000

Cortés Guzmán M et al., Nat Commun - This study identifies a pronounced germline mutational hotspot centered on transcription start sites (TSSs) driven in part by early embryonic mosaic variants and transcription-associated DNA damage. Key terms: transcription-start-sites, early-mosaicism, double-strand-breaks, mutational-signatures, promoter-mutations.

Study Highlights:
Extremely rare variants show a localized excess of non(CpG > TpG) mutations around TSSs extending several hundred base pairs, reaching ~35% enrichment at the 100-bp scale and ~14% at 1 kb. The hotspot is largely absent from de novo mutation calls because early mosaic variants are significantly enriched downstream of the TSS and are often filtered from family sequencing data. Regression and feature analyses link the TSS excess to divergent transcription, RNA polymerase II stalling, R-loop formation and somatic (mitotic) double-strand breaks rather than meiotic PRDM9-associated breaks. Mutational signature decomposition implicates non-canonical DSB repair (including TMEJ) and transcription-associated processes, and the hotspot preferentially affects genes related to cancer and developmental phenotypes.

Conclusion:
Transcription initiation regions are focal points of heritable variation shaped by early-development mosaicism and transcription-linked mitotic DNA damage, with implications for disease genetics and evolutionary constraint

Music:
Enjoy the music based on this article at the end of the episode.

First author:
Cortés Guzmán M

Journal:
Nature Communications

DOI:
10.1038/s41467-025-66201-0

Reference:
Cortés Guzmán M, Castellano D, Serrano Colomé C, Seplyarskiy V, Weghorn D. Transcription start sites experience a high influx of heritable variants fueled by early development. Nat Commun. 2025;16:10120. https://doi.org/10.1038/s41467-025-66201-0

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/tss-hotspot-early-development

️ Episode:
231: Transcription start sites as a germline mutational hotspot

️ Season:
1

Article title:
Transcription start sites experience a high influx of heritable variants fueled by early development

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-12-17.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Substantive audit of the transcript's articulation of the TSS mutational hotspot, early mosaic enrichment, drivers (divergent transcription, RNAP II stalling, R-loops), mitotic DSBs vs meiotic DSBs, mutational signatures, timing in early embryogenesis, and disease/evolutionary implications of the hotspot.
- transcript topics: Germline transcription start-site (TSS) mutational hotspot; Early mosaic variants and DNMs vs ERVs; Divergent transcription, RNAP II stalling, and R-loop formation as drivers; Mitotic vs meiotic double-strand breaks; Mutational signatures around the TSS (SBS3, SBS40b, SBS40c, SBS39); Timing during early embryogenesis (4-cell to 8-cell transition)

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Existence of a germline TSS mutational hotspot spanning hundreds of base pairs around the transcription start site (TSS).
- Hotspot not detectable in de novo mutation data due to enrichment of early mosaic variants and filtering in family sequencing data.
- Strong downstream enrichment of early mosaic variants immediately downstream of the TSS.
- Mutational hotspot associated with divergent transcription, RNA polymerase II stalling, and R-loops; linked to mitotic double-strand breaks but not meiotic breaks.
- Mutational signatures around the TSS implicate non-canonical DSB repair and transcription-associated mutagenesis (SBS3, SBS40b, SBS40c, SBS39).
- Temporal link: mutagenesis intensifies during the major transcriptional state shift between the 4-cell and 8-cell stages of development.

QC result: Pass.

230: MIDEAS Y654S hyperactivates MiDAC in a dominant neurodevelopmental syndrome

Gustavo Barra — Wed, 17 Dec 2025 05:18:17 +0000

Sirvydis K et al., Nat Commun - A recurrent de novo MIDEAS p.Tyr654Ser variant disrupts an autoinhibitory loop in the MiDAC complex, increasing HDAC1 deacetylase activity and causing a multisystem neurodevelopmental disorder. Key terms: MIDEAS, MiDAC, HDAC1, neurodevelopmental disorder, Y654S.

Study Highlights:
Two unrelated probands carry the same de novo heterozygous MIDEAS p.Tyr654Ser variant and present with speech delay, progressive joint contractures, facial dysmorphism and gastrointestinal dysmotility. A 2.9 Å cryo-EM structure shows Y654 lies in a conserved loop of MIDEAS that covers the HDAC1 active site and positions I659 into the active site channel. The Y654S change creates an STP CDK consensus site that is highly phosphorylated and leads to displacement of the inhibitory loop, producing a 3–5-fold increase in MiDAC deacetylase activity in vitro. Patient fibroblast transcriptomes display largely reciprocal gene expression changes compared with MiDAC-depleted cells, and MiDAC loss upregulates MAP2K6 and MAP2K3 implicating p38 MAPK pathway involvement.

Conclusion:
MIDEAS p.Tyr654Ser is a dominant monogenic cause of a neurodevelopmental syndrome driven by hyperactivity of the MiDAC HDAC complex

Music:
Enjoy the music based on this article at the end of the episode.

First author:
Sirvydis K

Journal:
Nat Commun

DOI:
10.1038/s41467-025-65472-x

Reference:
Sirvydis K., Fairall L., Knottnerus SJG., Gonchar O., Muskett FW., Jukes-Jones R., van Brussel L., van de Geer E., van Gassen K., Badenhorst P., van Hasselt PM., van Jaarsveld RH., Schwabe J.W.R., et al. A de novo missense variant in MIDEAS results in increased deacetylase activity of the MiDAC HDAC complex causing a neurodevelopmental syndrome. Nat Commun. 2025;16:10472. https://doi.org/10.1038/s41467-025-65472-x

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/mideas-y654s-midac-hyperactivity

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-12-17.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript's presentation of the paper's central mechanism: Y654S in MIDEAS causing MiDAC hyperactivity via disruption of an autoinhibitory loop; structural basis from cryo-EM; enzymatic gain-of-function; downstream gene expression and MAPK pathway implications; clinical phenotype overlap with related syndr
- transcript topics: MiDAC/MIDEAS composition and function; Y654S de novo variant and clinical phenotype; Cryo-EM structure showing autoinhibitory loop; HDAC activity assays and gain-of-function; CDK phosphorylation site creation and PTMs; Reciprocal gene expression changes and MAPK signaling

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Two unrelated probands carry de novo MIDEAS p.Tyr654Ser (Y654S) variant with overlapping neurodevelopmental features
- Y654S disrupts an autoinhibitory loop over the HDAC1 active site, leading to MiDAC hyperactivity
- Y654S creates a CDK phosphorylation site (STP) with phosphorylation detected, plausibly driving loop displacement
- Y654S complex shows 3–5-fold increased deacetylase activity compared with wild-type/loop-present complex
- Patient fibroblast expression changes reciprocally with MiDAC depletion; MAP2K6/MAP2K3 upregulation linked to MAPK signaling
- MiDAC acts as a brake on the p38 MAPK cascade; hyperactivity may drive the neurodevelopmental syndrome

QC result: Pass.

229: Inhibiting PCBP2 condensates in Alzheimer’s

Gustavo Barra — Mon, 15 Dec 2025 06:39:59 +0000

Wang L et al., Nat Commun - Elevated PCBP2 forms liquid-like condensates that sequester mitochondrial and RNA-binding proteins, stabilize BACE1 mRNA, and promote amyloid pathology while the small molecule CN-0928 reduces PCBP2 via INTS1 to lower Aβ and improve cognition in AD models. Key terms: PCBP2, biomolecular condensates, BACE1, CN-0928, mitochondria.

Study Highlights:
PCBP2 protein is increased in AD patient brains and AD mouse models and forms enlarged, dynamic cytoplasmic condensates that undergo LLPS in vitro and in cells. PCBP2 condensates concentrate mitochondrial proteins and RNA-binding/NMD factors including UPF1, correlating with disrupted mitochondrial morphology, increased ROS, and reduced mitochondrial respiration. PCBP2 stabilizes BACE1 mRNA by sequestering NMD components into condensates and thereby impairs 3′UTR-dependent decay. The small molecule CN-0928 binds INTS1 at Arg-1404, lowers PCBP2 transcription and protein levels, reduces condensates, decreases BACE1 and Aβ, and improves cognitive performance in 5×FAD mice

Conclusion:
Targeting PCBP2 biomolecular condensates via INTS1 with CN-0928 offers a novel strategy to mitigate mitochondrial dysfunction and BACE1-driven amyloidogenesis in Alzheimer’s disease

Music:
Enjoy the music based on this article at the end of the episode.

First author:
Wang L

Journal:
Nat Commun

DOI:
10.1038/s41467-025-65547-9

Reference:
Wang L, Xie X-Y, Pan Q-L, Zhang J, Zhou G-F, Zhang Q-L, Yan X-X, Xiang Y, Li C-L, He Y, Xiang X-J, Deng X-J, Wang Y-J, Zhou J-Y, Nie S & Chen G-J. Pharmacologic inhibition of PCBP2 biomolecular condensates relieves Alzheimer’s disease. Nat Commun. 2025;16:10514. https://doi.org/10.1038/s41467-025-65547-9

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/pcbp2-condensates-alzheimers

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-12-15.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the central mechanistic narrative (PCBP2 condensates, LLPS, mitochondrial sequestration, UPF1/BACE1 3'UTR regulation) and the therapeutic axis (CN-0928/INTS1) with in vivo cognitive outcomes in mouse models.
- transcript topics: PCBP2 elevation and LLPS condensates in AD models; Sequestration of mitochondrial proteins and UPF1; Mitochondrial dysfunction and ROS/ respiration effects; BACE1 mRNA stability via 3'UTR and UPF1 sequestration; CN-0928 reduces PCBP2 condensates and lowers BACE1/Aβ; INTS1 as CN-0928 target and Arg-1404 binding site

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- PCBP2 levels elevated in AD brains and in AD mouse models
- PCBP2 forms biomolecular condensates that undergo LLPS
- PCBP2 condensates sequester mitochondrial proteins and UPF1
- Sequestration links to mitochondrial dysfunction (morphology, ROS, respiration)
- PCBP2 stabilizes BACE1 mRNA via 3'UTR and reduces mRNA decay
- CN-0928 reduces PCBP2 and condensates, lowers BACE1 and Aβ, improves cognition in 5×FAD mice

QC result: Pass.

228: Two non-competing H3N2 stem antibodies reveal evolving antigenicity

Gustavo Barra — Sun, 14 Dec 2025 10:15:41 +0000

Gopal AB et al., Nat Commun - Structural and functional characterization of two group 2 H3 HA stem antibodies, 2F02 and AG2-G02, shows distinct non-overlapping epitopes, protection in mice, and antigenic changes driven by HA2 position 32 that limit AG2-G02 binding. Key terms: influenza H3N2, hemagglutinin stem, broadly neutralizing antibodies, antigenic evolution, vaccine design.

Study Highlights:
Cryo-EM structures show 2F02 targets the central stem epitope while AG2-G02 targets the lower stem epitope and the two can bind concurrently to an HA trimer. Both antibodies neutralize diverse H3 strains in vitro and provide prophylactic protection in mice, with Fc-mediated effector functions contributing to in vivo efficacy. AG2-G02 binding is lost to recent human H3N2 HAs carrying R32 at HA2, whereas T32 or I32 permit binding. Human plasma binding profiles mirror the historical shift from T32 to I32 to R32, indicating altered population antigenicity of the lower stem over time.

Conclusion:
Natural evolution at HA2 position 32 has changed the antigenicity of the H3N2 HA lower stem, impacting binding of certain group 2 stem antibodies and informing vaccine design strategies

Music:
Enjoy the music based on this article at the end of the episode.

First author:
Gopal AB

Journal:
Nat Commun

DOI:
10.1038/s41467-025-65595-1

Reference:
Gopal AB, Lv H, Ouyang WO, Teo QW, Luo Y, Tang YS, Luo M, Mok CKP, Wu NC. Characterization of two non-competing antibodies to influenza H3N2 hemagglutinin stem reveals its evolving antigenicity. Nat Commun. 2025;16:10557. https://doi.org/10.1038/s41467-025-65595-1

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/h3n2-stem-antibodies-evolution

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-12-14.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited sections discussing: identification and epitopes of AG2-G02 and 2F02; structural/functional characterization; concurrent binding to an HA trimer; antigenic evolution at HA2 position 32; Fc-mediated protection in vivo; serological/population memory implications; vaccine-design implications.
- transcript topics: Identification and non-overlapping epitopes of AG2-G02 (lower stem) and 2F02 (central stem); Cryo-EM structural analysis and concurrent binding to an HA trimer; Antigenic evolution at HA2 position 32 (T32, I32, R32) and its effect on binding; In vivo Fc-mediated protection and importance of Fc effector functions; Serological analysis across pre-2003 adults, post-2011 adults, and post-2011 infants; Implications for universal influenza vaccine design targeting multiple stem epitopes

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- AG2-G02 targets the lower stem epitope; 2F02 targets the central stem epitope; epitopes are distinct and non-overlapping
- AG2-G02 and 2F02 can bind concurrently to the same HA trimer (non-competitive binding with six Fabs on a single trimer)
- AG2-G02 binding to H3 stem is abrogated by R32HA2; T32HA2 and I32HA2 permit binding
- Population plasma shows immune imprinting: pre-2003 adults bind more to T32HA2; post-2011 infants show stronger binding to R32HA2; post-2011 adults show intermediate patterns
- Fc-mediated effector functions are required for in vivo protection; LALA-PG variants reduce protection
- Two antibodies provide a blueprint for vaccines by targeting both central and lower stem epitopes

QC result: Pass.

227: 1q gain enables rescue of aneuploid hESCs during RPE differentiation

Gustavo Barra — Sat, 13 Dec 2025 06:36:42 +0000

Couvreu de Deckersberg E et al., Nat Commun (2025) - This study shows that spontaneous RPE differentiation eliminates most aneuploid human pluripotent stem cells but permits expansion of cells with chromosome 1q gains when they are co-cultured with wild-type cells. Key terms: aneuploidy, 1q gain, RPE differentiation, co-culture, wild-type rescue.

Study Highlights:
Large-scale single-cell genomics revealed pervasive low-grade mosaicism in genetically balanced hPSC cultures, with 3–6% of cells carrying various aneuploidies. During undirected RPE differentiation most aneuploid lineages are purged, except for cells bearing gains of chromosome arm 1q which persist. 1q-gain cells only complete neural/RPE specification when co-cultured with wild-type cells that provide paracrine ligands and induce neuroectodermal regulons, enabling rescued differentiation trajectories. Rescued RPE1q cells show comparable RPE marker expression but display transcriptional signs of aneuploidy-related stress and can outcompete wild-type and other aneuploid cells, whereas 20q11.21 gains, iso20q and trisomy 20 generally fail to be rescued.

Conclusion:
Spontaneous RPE differentiation acts as a selective bottleneck removing most aneuploid cells but permits expansion of 1q-gain clones via wild-type co-culture rescue, underscoring the importance of genomic surveillance for hPSC-derived therapies

Music:
Enjoy the music based on this article at the end of the episode.

First author:
Couvreu de Deckersberg E

Journal:
Nat Commun (2025)

DOI:
10.1038/s41467-025-66766-w

Reference:
Couvreu de Deckersberg E, Lei Y, Krivec N, Huyghebaert A, Duong MC, Janssens C, Regin M, Tsuiko O, Movahedi K, Verhulst S, van Grunsven LA, Sermon K, Al Delbany D, Spits C. 1q gain bypasses the selective barrier against aneuploidy in RPE differentiation via wild-type co-culture rescue. Nat Commun (2025). https://doi.org/10.1038/s41467-025-66766-w

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/1q-gain-wild-type-rescue

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-12-13.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the spoken content covering: baseline mosaicism in hPSCs, the selective bottleneck during RPE differentiation, the 1q-gain rescue via co-culture, the MDM4/p53 mechanism, signaling interactions with wild-type neighbors, and comparisons to other aneuploides; also covered limitations and safety considerations.
- transcript topics: hPSC mosaicism and common aneuploidies; undirected RPE differentiation bottleneck; 1q gain persistence and enrichment; wild-type co-culture rescue mechanism; MDM4/p53 axis and stress responses; signaling interactions between wt and 1q-gain cells

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Prevalence of low-grade mosaicism in hPSC cultures (3-6%).
- During undirected RPE differentiation, most aneuploidies are eliminated except 1q gains.
- 1q-gain cells differentiate efficiently only when co-cultured with wild-type cells via paracrine signals.
- 1q-gain cells can expand and dominate the culture (up to ~43% of final population in a line).
- MDM4 copy number in 1q gain inhibits p53, enabling survival through differentiation.
- Specific wt–1q ligand–receptor interactions (e.g., NRXN1–NLGN1, EFNA5–EPHA6, CALM1/2/3–RYR2/CACNA1C) mediate rescue.

QC result: Pass.

226: FGF4 protects podocytes in diabetic kidney disease

Gustavo Barra — Fri, 12 Dec 2025 06:03:01 +0000

Wang S et al., Nat Commun - This study shows that podocyte-derived FGF4 is reduced in DKD and that recombinant FGF4 preserves podocyte survival and glomerular function in diabetic models via FGFR1-AMPK-FOXO1 signaling. Key terms: FGF4, FGFR1, podocyte, AMPK-FOXO1, diabetic kidney disease.

Study Highlights:
FGF4 expression is downregulated in kidneys from DKD patients and diabetic mouse models and localizes predominantly to podocytes. Podocyte-specific deletion of Fgf4 worsened albuminuria, reduced GFR, increased oxidative stress and podocyte loss in diabetic mice. Systemic treatment with a non-mitogenic recombinant FGF4 improved glucose in db/db mice, lowered UACR and BUN, reduced fibrosis, ROS and apoptosis, and restored podocyte markers in both T1D and T2D models. The protective effects of rFGF4 require podocyte FGFR1 and downstream AMPK-FOXO1 activity, as Fgfr1, Ampk, or Foxo1 podocyte knockouts abolished rFGF4 benefits. rFGF4 also reversed high glucose–induced injury and promoted nuclear FOXO1 in human podocytes and isolated human glomeruli

Conclusion:
FGF4 is a podocyte-derived regulator that promotes podocyte survival and mitigates DKD through FGFR1-mediated activation of the AMPK-FOXO1 axis, supporting rFGF4 as a potential therapeutic approach for diabetic kidney disease

Music:
Enjoy the music based on this article at the end of the episode.

First author:
Wang S

Journal:
Nat Commun

DOI:
10.1038/s41467-025-65978-4

Reference:
Wang S, Lou J, Pan B, Zhao M, Li Q, Zhou J, et al. FGF4-FGFR1 signaling promotes podocyte survival and glomerular function to ameliorate diabetic kidney disease in male mice. Nat Commun. 2025;16:10430. https://doi.org/10.1038/s41467-025-65978-4

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/fgf4-podocyte-protects-kidney

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-12-12.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the scientific content of the transcript, focusing on: DKD context and podocyte injury; FGF4 downregulation and podocyte-specific Fgf4 knockout effects; rFGF4 therapeutic effects in DKD mouse models; FGFR1-AMPK-FOXO1 signaling; human cell data; safety considerations; interactions with losartan and SGLT2 inhibit
- transcript topics: DKD and podocyte injury; FGF4 as a podocyte-protective factor; Podocyte-specific Fgf4 knockout model (PKO); Recombinant FGF4 therapy in DKD (db/db and STZ models); FGFR1-AMPK-FOXO1 signaling axis; Human podocyte/glomerulus data and translational relevance

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- DKD downregulates FGF4 in podocytes and correlates with disease severity
- Podocyte-specific deletion of Fgf4 worsens DKD outcomes (lower GFR, higher albuminuria, histological damage)
- Recombinant FGF4 (rFGF4) protects against DKD in two mouse models (db/db and STZ), reducing kidney injury and fibrosis
- FGFR1-AMPK-FOXO1 signaling mediates rFGF4's protective effects in podocytes
- Protection by rFGF4 is non-glycemic and can occur even when blood glucose remains high
- Human relevance: rFGF4 reverses injury in human podocytes and human glomeruli under high glucose

QC result: Pass.

225: VRK-1, BAF-1 and the release of meiotic chromatin

Gustavo Barra — Wed, 10 Dec 2025 23:08:49 +0000

Paouneskou D et al., Nature Communications - VRK-1 phosphorylates BAF-1 to remove chromatin from the nuclear periphery during early meiotic prophase in C. elegans, and failure of this step impairs pairing and synapsis and generates heritable genome lesions. Key terms: VRK-1, BAF-1, meiosis, chromatin tethering, genome integrity.

Study Highlights:
The authors used an auxin-inducible VRK-1 depletion system and genetic perturbations to show that VRK-1 phosphorylates BAF-1 (Ser4) to release chromatin–nuclear periphery contacts during leptotene–zygotene. VRK-1 loss or a BAF-1 Ser4 phospho-mutant increases chromatin tethering at the nuclear envelope, delays homolog pairing, slows and disrupts synaptonemal complex assembly, and elevates apoptosis. VRK-1 depletion produces oocytes with increased DAPI bodies, intrachromosomal bridges and fragmentation that depend on SPO-11 and MSH-5, while baf-1 RNAi rescues overtethering phenotypes. Transient VRK-1 loss during the chromosome movement window yields offspring with an increased burden of deletions and duplications detected by long-read sequencing, implicating VRK-1–BAF-1 in preserving genome integrity

Conclusion:
Timed VRK-1–mediated phosphorylation of BAF-1 is required to detach chromatin from the nuclear periphery during meiotic chromosome movements to ensure correct pairing, synapsis, and genome stability

Music:
Enjoy the music based on this article at the end of the episode.

First author:
Paouneskou D

Journal:
Nature Communications

DOI:
10.1038/s41467-025-65420-9

Reference:
Paouneskou D., Baudrimont A., Elkrewi M., Kölbl C., Tiemann-Boege I., Vicoso B., Jantsch V. BAF-1–VRK-1 mediated release of meiotic chromosomes from the nuclear periphery is important for genome integrity. Nature Communications. 2025;16:10446. https://doi.org/10.1038/s41467-025-65420-9

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/vrk1-baf1-meiosis-integrity

️ Episode:
225: VRK-1 and BAF-1 release meiotic chromosomes

️ Season:
1

Article title:
BAF-1–VRK-1 mediated release of meiotic chromosomes from the nuclear periphery is important for genome integrity

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-12-10.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript’s presentation of the VRK-1–BAF-1 mechanism, effects of VRK-1 depletion on chromatin tethering and meiosis (pairing, SC, CO), apoptosis, and the heritable genome-variant outcomes revealed by long-read sequencing, plus rescue and repair pathway details described in the article.
- transcript topics: Meiosis in C. elegans and rapid chromosome movements; Chromatin tethering to nuclear periphery (BAF-1); VRK-1 kinase and BAF-1 Ser4 phosphorylation; AID timing window for VRK-1 depletion; Synapsis and CO formation (HTP-3, SYP-1, MSH-5, ZHP-3); DNA repair pathways and alternative repair (MUS-81, POLQ-1, NHEJ)

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- VRK-1 phosphorylates BAF-1 at Ser4 to detach chromatin from the nuclear periphery during early meiotic prophase
- VRK-1 depletion leads to chromatin tethering, delayed pairing and synapsis, and elevated apoptosis
- BAF-1 Ser4 phosphorylation is a VRK-1 target; BAF-1 Ser4 phospho-mutant phenocopies VRK-1 depletion regarding chromosome reorganization
- Synapsis is delayed and crossover (CO) formation is perturbed (MSH-5 recruitment delayed; ZHP-3 retraction delayed) in VRK-1–depleted cells
- Transient VRK-1 depletion yields offspring with increased deletions and duplications (SVs) detected by long-read sequencing; large SVs (>10 kb) increased >6-fold
- Alternative repair pathways (MUS-81, POLQ-1) are engaged under VRK-1 depletion and influence chromosome integrity

QC result: Pass.

224: Biohybrid implants: wireless sensing with engineered bacteria

Gustavo Barra — Wed, 10 Dec 2025 19:35:04 +0000

Bilir A et al., Wireless in-body sensing through genetically engineered bacteria - A bio-hybrid, battery-free implant converts engineered bacterial activity into microwave backscatter signals by controlled degradation of a biodegradable antenna. Key terms: engineered bacteria, biodegradable antenna, backscatter communication, implantable sensor, cytochrome c.

Study Highlights:
The AntennAlive system uses a magnesium split-ring passive implant antenna coupled with genetically engineered Escherichia coli that accelerate metal degradation to convert molecular detection into an electromagnetic signature. E. coli BL21 engineered to express the CcmA–H cytochrome c maturation pathway degraded the magnesium prototype faster (≈8 h) than non-engineered cells (≈14 h), causing a controlled structural transition from split ring to segmented ring. Numerical and experimental work showed resonant frequencies near 1.16 GHz for the intact antenna and 1.91 GHz after degradation, and an on-body reader antenna covering 0.8–2.3 GHz enabled backscatter monitoring through a muscle phantom. A wireless, chipless link between the cell-based passive implant and an external receiver was demonstrated at 25 mm implant depth, showing potential for molecular-level in-body sensing without batteries or electronics.

Conclusion:
Genetically programmed bacteria can modulate biodegradable antenna properties to produce remotely detectable backscatter signals, enabling battery-free, implantable molecular sensing.

Music:
Enjoy the music based on this article at the end of the episode.

First author:
Bilir A

Journal:
Nature Communications

DOI:
10.1038/s41467-025-65416-5

Reference:
Bilir A., Yavuz M., Safak Seker U. O., Dumanli S. Wireless in-body sensing through genetically engineered bacteria. Nature Communications. 2025;16:10432. https://doi.org/10.1038/s41467-025-65416-5

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/antennalive-bacterial-implant

️ Episode:
224: AntennAlive — wireless in-body sensing with engineered bacteria

️ Season:
1

Article title:
Wireless in-body sensing through genetically engineered bacteria

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-12-10.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript's coverage of AntennAlive concept, magnesium-based passive implant, engineered E. coli (CcmA–H), degradation-driven resonant-frequency shift, experimental phantom setup, 25 mm depth demonstration, and discussed limitations/future work.
- transcript topics: AntennAlive concept and biohybrid sensing bridge; Magnesium-based passive implant antenna design and degradation; Engineering E. coli for extracellular electron transfer (CcmA–H); Degradation dynamics and resonance shift (1.16 GHz to 1.91 GHz); Experimental setup: muscle phantom, Mg foil, on-body reader, VNA; Phantom-based wireless backscatter demonstration at 25 mm depth

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Mg foil implant is 25 μm thick and degrades faster under engineered bacteria
- E. coli BL21 expressing CcmA–H accelerates magnesium degradation vs non-engineered BL21
- Degradation changes implant antenna from split ring to segmented ring
- Resonant frequency shifts from ~1.16 GHz (intact) to ~1.91 GHz (degraded)
- Wireless backscatter link detected by on-body reader at 25 mm depth in a muscle phantom
- Non-biodegradable implant resonance detectable up to 55 mm depth

QC result: Pass.

223: Torsion Controls Replication: Stall and Restart

Gustavo Barra — Tue, 09 Dec 2025 06:22:34 +0000

Xiaomeng Jia et al., Berger, Smita S - New single-molecule angular optical trap assays reveal that DNA torsion directly controls T7 replisome stalling and reactivation. Key terms: DNA replication, torsion, replisome, helicase, DNA polymerase.

Study Highlights:
A high-resolution, label-free angular optical trap (AOT) assay was developed to track T7 replisome-driven DNA rotation and torsional slowing in real time. The combined helicase–DNA polymerase (DNAP) replisome generates ∼22 pN·nm of stall torque, about twice that of E. coli RNA polymerase, while helicase or DNAP alone produce minimal positive torque. Loss of the helicase C‑terminal domain interaction with DNAP increases fork regression under torsion and reduces restart efficiency, and prolonged stalling leads to replisome inactivation. Excess free DNAP at the fork and gyrase-mediated torsional relaxation substantially improve restart after a torsion-induced stall

Conclusion:
Torsional stress is a central regulator of fork stability and restart, with helicase–DNAP synergy and timely topoisomerase activity determining whether stalled replisomes reactivate

Music:
Enjoy the music based on this article at the end of the episode.

First author:
Xiaomeng Jia

Journal:
Nature Communications

DOI:
10.1038/s41467-025-65567-5

Reference:
Xiaomeng Jia, Xiang Gao, Shuming Zhang, James T. Inman, Yifeng Hong, Anupam Singh, Fahad Rashid, James M. Berger, Smita S. Patel & Michelle D. Wang. Torsion is a dynamic regulator of DNA replication stalling and reactivation. Nat Commun. 2025;16:10543. https://doi.org/10.1038/s41467-025-65567-5

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/torsion-dna-replication-restart

️ Episode:
223: Torsion Regulates DNA Replication Stalling and Restart

️ Season:
1

Article title:
Torsion is a dynamic regulator of DNA replication stalling and reactivation

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-12-09.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the substantive scientific content describing torque generation by the T7 replisome, stall under torsion, fork regression, restart mechanisms (including excess DNAP and CTD recruitment), and gyrase effects; cross-checked against the original article.
- transcript topics: Torque generation by the T7 replisome (AOT measurements); Stalling of replication under torsion and stall torque values; CTD-mediated helicase–DNAP interaction and fork stability; Fork regression dynamics under torsion; Excess DNAP and DNAP exchange promoting fork restart; Gyrase/topoisomerase role in torque relief and restart

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- WT replisome stalls at ~21.9 ± 4.4 pN·nm (≈22 pN·nm) torque when helicase and DNAP act together
- DNAP alone and helicase alone generate minimal positive torsion (DNAP ≈ -1.5 ± 2.4 pN·nm; helicase ≈ 1.2 ± 5.0 pN·nm)
- ΔCt helicase (lacking CTD-DNAP interaction) replisome stalls with torque ~19.4 ± 3.0 pN·nm
- Fork regression distances under stall: WT ~80 bp; ΔCt ~240 bp; ΔCtexo ~340 bp
- Prolonged stalling reduces restart efficiency; short stalls restore better than long stalls
- Excess DNAP during a long stall increases restart fraction from ~40% to ~85%

QC result: Pass.

222: snaR-A disrupts mRNA splicing in cancer

Gustavo Barra — Mon, 08 Dec 2025 05:39:07 +0000

Zhou S et al., Nat Commun - This episode examines how the cancer-associated Pol III transcript snaR-A binds core splicing factors, localizes near nuclear speckles, perturbs U2-dependent splicing to increase intron retention, and promotes cell proliferation linked to poorer patient outcomes. Key terms: snaR-A, splicing, SF3B2, intron retention, nuclear speckles.

Study Highlights:
Proteomic pull-downs and CLIP analyses reveal snaR-A interactions with RNA chaperones (La, ILF3) and multiple splicing factors, with PAR-CLIP and CLIP-qPCR supporting a direct interaction with the U2 snRNP subunit SF3B2. HCR-RNA-FISH and SON TSA-seq place snaR-A in subnuclear foci adjacent to nuclear speckles and show snaR-A gene clusters are speckle-proximal. Functional genomics show snaR-A overexpression increases intron retention while snaR-A depletion reduces intron retention and enhances splicing of transcripts marked by high U2 occupancy and speckle proximity, and snaR-A overexpression selectively reduces SF3B2 protein levels. Phenotypically, snaR-A depletion lowers proliferation in HEK293T cells, snaR-A gene activity correlates with proliferation markers across primary tumors and predicts worse survival, and rescued splicing increases protein abundance for tumor-suppressive targets such as OGFR.

Conclusion:
snaR-A acts as a nuclear antagonist of U2-dependent splicing near speckles, promoting cell proliferation and providing a non-mutational route to splicing dysregulation in cancer

Music:
Enjoy the music based on this article at the end of the episode.

First author:
Zhou S

Journal:
Nature Communications

DOI:
10.1038/s41467-025-65448-x

Reference:
Zhou S, Lizarazo S, Chorghade S, Mouli L, Cheng R, KC R, Kalsotra A, Van Bortle K. Cancer-associated snaR-A noncoding RNA interacts with core splicing machinery and disrupts processing of mRNA subpopulations. Nat Commun. 2025;16:10460. https://doi.org/10.1038/s41467-025-65448-x

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/snar-a-splicing-disruption

️ Episode:
222: snaR-A hijacks splicing to drive proliferation

️ Season:
1

Article title:
Cancer-associated snaR-A noncoding RNA interacts with core splicing machinery and disrupts processing of mRNA subpopulations

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-12-08.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript's core mechanistic and phenotypic claims described in the Nature Communications article: snaR-A interactions with SF3B2 and splicing machinery, subnuclear speckle localization, intron retention changes with overexpression/depletion, effects on proliferation and OGFR, and clinical correlations.
- transcript topics: Pol III overactivity and snaR-A origin in cancer; snaR-A interactions with splicing factors (SF3B2, U2 snRNP); subnuclear localization near nuclear speckles; intron retention and splicing efficiency changes; effects of snaR-A depletion/overexpression on proliferation and OGFR; clinical associations: snaR-A activity and patient survival

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- snaR-A interacts with core mRNA splicing machinery including SF3B2
- snaR-A localizes near nuclear speckles and associates with splicing factors
- overexpression of snaR-A increases intron retention, especially for U2-bound, speckle-proximal transcripts
- depletion of snaR-A reduces intron retention and improves splicing of U2-resident, speckle-proximal transcripts
- splicing improvements after snaR-A depletion correlate with increased OGFR protein levels (tumor suppressor)
- snaR-A depletion reduces cell proliferation in HEK293T cells

QC result: Pass.

221: Allele-resolved nanopore tour of the human placental methylome

Gustavo Barra — Sun, 07 Dec 2025 09:22:31 +0000

Kindlova M et al., Nat Commun - Using phased long-read nanopore and short-read sequencing across eight trios, the study maps allele-specific DNA methylation and transcription in female human placentas, identifies hundreds of DMRs and novel imprinted genes, and reports somatic placental variants. Key terms: placenta, nanopore sequencing, DNA methylation, imprinting, allele-specific expression.

Study Highlights:
The authors combined >20x Oxford Nanopore whole-genome sequencing with Illumina WGS and RNA-seq in eight mother–father–placenta trios to phase reads into maternal and paternal alleles. They catalogued 723 differentially methylated regions, finding a strong bias toward paternal demethylation concentrated in partially methylated domains. Allele-resolved expression analysis identified 74 imprinted genes and revealed previously unreported imprinted loci including paternally expressed ILDR2 and maternally expressed RASA1. The study also detected widespread somatic point mutations and a small number of placenta-specific structural variants, including a CNDP1–ZNF407 duplication associated with altered gene expression

Conclusion:
Phased nanopore sequencing provides a high-resolution, allele-specific map of the placental methylome and transcriptome, revealing novel imprinted genes and somatic variation with potential relevance to placental biology

Music:
Enjoy the music based on this article at the end of the episode.

First author:
Kindlova M

Journal:
Nat Commun

DOI:
10.1038/s41467-025-65337-3

Reference:
Kindlova M, Byrne H, Kubler JM, Steane SE, Whyte JM, Borg D, Clifton VL & Ewing AD. An allele-resolved nanopore-guided tour of the human placental methylome. Nat Commun. 2025;16:10358. https://doi.org/10.1038/s41467-025-65337-3

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/allele-resolved-placental-methylome

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-12-07.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Substantively audited the transcript’s coverage of allele-resolved placental methylome mapping, DMRs, imprinting, specific imprinted genes ILDR2 and RASA1, the C19MC locus, SST1 repeats, somatic variation including CNDP1–ZNF407, and X-chromosome methylation, plus study limitations and conclusions.
- transcript topics: Allele-resolved methylome mapping by nanopore sequencing; Trio-based phasing and parental allele assignment; Global methylation patterns and PMDs in placenta; Differentially methylated regions (DMRs) and paternal demethylation bias; Imprinted genes ILDR2 and RASA1; C19MC locus and SST1 macro-satellite region

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Eight female placentas were sequenced in eight mother–father–placenta trios
- Long-read nanopore sequencing with trio-based phasing enables allele-specific methylation and transcription mapping, with EM-seq validation showing high concordance (~94%)
- Identified 723 differentially methylated regions (DMRs), including 184 novel DMRs
- Large majority of DMRs show paternal demethylation bias
- ILDR2 is paternally demethylated and expressed; RASA1 is maternally demethylated and expressed
- C19MC locus encodes paternally expressed miRNAs; SST1 macro-satellite region shows paternal methylation pattern with transcription initiated at a HERVH element

QC result: Pass.

220: AML cell states reveal NPM1 immune-evasion subtypes

Gustavo Barra — Sat, 06 Dec 2025 08:46:36 +0000

Lilljebjörn H et al., Nat Commun - Single-cell and bulk sequencing of 120 AML cases reveal two NPM1-mutated subtypes with distinct immune evasion mechanisms and divergent responses to hematopoietic stem cell transplantation. Key terms: acute myeloid leukemia, single-cell RNA-seq, NPM1, immune evasion, hematopoietic stem cell transplantation.

Study Highlights:
Bulk RNA-seq profiles are strongly confounded by variable mature cell-type signatures that can conceal subtype-specific blast programs. Single-cell multimodal sequencing of AML identified four main clusters of immature leukemic cells and separated NPM1-mutated cases into NPM1class I and NPM1class II. NPM1class I is marked by MHC class II downregulation and shows a significant survival benefit from HSCT, while NPM1class II resists allogeneic T cell killing ex vivo and does not benefit from HSCT. A 180-gene signature, and a shorter 30-gene panel, distinguished the classes across external bulk cohorts and associated each subtype with different co-mutation patterns.

Conclusion:
Single-cell transcriptional profiling defines two clinically relevant NPM1 subtypes with distinct immune evasion strategies that may inform HSCT decisions and immunotherapy approaches.

Music:
Enjoy the music based on this article at the end of the episode.

First author:
Lilljebjörn H

Journal:
Nature Communications

DOI:
10.1038/s41467-025-66546-6

Reference:
Lilljebjörn H, Henningsson R, Rissler M, Landberg N, Puente-Moncada N, von Palffy S, Rissler V, Stanek P, Desponds J, Lazarevic V, Lehmann S, Fontes M, Ågerstam H, Sandén C, Orsmark-Pietras C, Zhong X, Juliusson G, Thorsson H, Fioretos T. The AML cellular state space unveils NPM1 immune evasion subtypes with distinct clinical outcomes. Nat Commun. 2025;16:10592. https://doi.org/10.1038/s41467-025-66546-6

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/npm1-immune-evasion-subtypes

️ Episode:
220: The AML cellular state space reveals NPM1 immune evasion subtypes

️ Season:
1

Article title:
The AML cellular state space unveils NPM1 immune evasion subtypes with distinct clinical outcomes

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-12-06.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript sections describing AML heterogeneity, single-cell sequencing approaches, isolation of AML immature cells, the NPM1 class I/II dichotomy, MHC-II downregulation and CIITA, intrinsic T cell resistance, ex vivo T cell assays, HSCT outcomes, and the minimal 30-gene panel for clinical implementation.
- transcript topics: AML heterogeneity and leukemia stem cells; Single-cell multimodal sequencing (scRNA-seq + scADT-seq); Isolation and characterization of AML immature cells; NPM1-mutated AML: NPM1 class I and NPM1 class II; MHC class II downregulation and CIITA regulation; Intrinsic T cell resistance and alternative checkpoint pathways

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- AML heterogeneity and leukemia stem cells drive relapse
- Single-cell multimodal sequencing identifies AML immature cells and two NPM1 subtypes
- NPM1 class I downregulates MHC II and HSCT improves survival
- NPM1 class II shows intrinsic resistance to donor T cells and lacks HSCT benefit
- Ex vivo T cell co-culture shows differential sensitivity between NPM1 classes I and II
- A minimal 30-gene expression panel can distinguish the two NPM1 subtypes for clinical use

QC result: Pass.

219: Multi-omic mapping of lipid dysregulation in Parkinson’s brain

Gustavo Barra — Sat, 06 Dec 2025 08:11:05 +0000

Hällqvist J et al., Nature Communications - Targeted multi-region lipidomics with proteomic and mitochondrial data reveals region- and stage-specific lipid alterations in Parkinson’s disease that converge on mitochondrial dysfunction. Key terms: lipids, parkinsons disease, putamen, ceramide, plasmalogens.

Study Highlights:
The study quantified 146 lipid species across eight anatomically distinct post-mortem brain regions in controls and mid- and late-stage Parkinson’s disease using targeted LC-MS/MS and integrated proteomics and mitochondrial assays. Control brains showed distinct regional lipid signatures and age-associated increases in hexosylceramides, while PD brains exhibited cortical elevations of gangliosides, HexCer and Hex2Cer and subcortical reductions of glycosphingolipids alongside increased sphingolipids and decreased phospholipids. The putamen displayed the most pronounced mid-stage changes with depletion of very long-chain ceramides and plasmalogen PE that normalized in late-stage disease, and lyso-phosphatidylcholine rose progressively with disease stage. Correlative multi-omic analysis linked sphingomyelin species to PD-related proteins and associated putaminal lipids including plasmalogens, long-chain ceramides, lyso-PC and HexCer with altered mitochondrial complex I activity.

Conclusion:
Region- and stage-specific lipid remodeling in Parkinson’s disease converges with mitochondrial dysfunction and identifies lipid pathways that may contribute to disease progression and therapeutic targeting

Music:
Enjoy the music based on this article at the end of the episode.

First author:
Hällqvist J

Journal:
Nature Communications

DOI:
10.1038/s41467-025-65489-2

Reference:
Hällqvist J, Toomey CE, Pinto R, Baldwin T, Doykov I, Wernick A, Al Shahrani M, Evans JR, Lachica J, Pope S, Heales S, Eaton S, Mills K, Gandhi S & Heywood WE. Multi-omic analysis reveals lipid dysregulation associated with mitochondrial dysfunction in Parkinson’s disease brain. Nature Communications. 2025;16:10490. https://doi.org/10.1038/s41467-025-65489-2

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/lipid-dysregulation-parkinsons-brain

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-12-06.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Substantive auditing of the transcript's scientific claims about regional lipid remodeling in PD, ceramide chain-length shifts, putamen-specific changes, mitochondrial correlations, and multi-omic integration, with attention to disease progression and potential protective responses.
- transcript topics: Regional lipid remodeling across eight brain regions; Ceramide chain-length alterations (short vs very long); Putamen mid-stage changes and plasmalogen PE; Glycosphingolipid patterns cortical vs subcortical; Lyso-phospholipids and plasmalogens across PD stages; Lipid-proteomics and mitochondrial complex I correlations

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- 8 anatomically distinct brain regions analyzed
- 146 lipid species quantified
- Braak staging used: mid-stage Braak 3-4 and late-stage Braak 5-6
- Putamen mid-stage shows depletion of very long-chain ceramides and plasmalogen PE
- Short-chain ceramides (C16, C18) elevated broadly in PD
- Cortical regions show increased glycosphingolipids (GM1, GM2, GM3) while subcortical regions show decreases

QC result: Pass.

218: SIM1 and the multi-ancestry genomics of erectile dysfunction

Gustavo Barra — Thu, 04 Dec 2025 07:36:26 +0000

Bright U et al., Nat Commun - A large multi-ancestry GWAS meta-analysis identifies a dominant SIM1-linked locus and multiple genetic connections between electronic health record-defined erectile dysfunction and cardiometabolic, psychiatric, and substance-use traits. Key terms: erectile dysfunction, GWAS, SIM1, obesity, polygenic risk.

Study Highlights:
Meta-analysis of 913,194 European and 125,315 African ancestry individuals (136,867 and 51,599 cases respectively) identified 40 independent variants in Europeans, two in Africans, and 51 lead SNPs in cross-ancestry analyses. The strongest associations mapped to a non-coding region regulating SIM1, led by rs78677597 in Europeans and rs17185536 in Africans and in the cross-ancestry meta-analysis. Genetic correlations and local analyses linked EHR-defined ED with psychiatric disorders, cardiometabolic traits, and substance use traits, and Mendelian randomization inferred bidirectional and directional causal relationships involving obesity, type 2 diabetes, cannabis use disorder and opioid use disorder. Polygenic risk scores explained up to 9.2% of variance but showed limited predictive power (AUC = 0.52), while gene-based and TWAS analyses highlighted ESR1, CTNNB1 and SLC39A8 and drug-repurposing nominated ER-α antagonists and sulindac as candidates.

Conclusion:
The study confirms a dominant SIM1-associated genetic signal for erectile dysfunction and reveals a complex, multi-factorial genetic architecture linking ED to cardiometabolic, psychiatric, and substance-use biology

Music:
Enjoy the music based on this article at the end of the episode.

First author:
Bright U

Journal:
Nat Commun

DOI:
10.1038/s41467-025-66723-7

Reference:
Bright U, Chen Y, Deak JD, Zhou H, Levey DF, Gelernter J. Multi-ancestry investigation of the genomics of erectile dysfunction. Nat Commun. 2025. https://doi.org/10.1038/s41467-025-66723-7

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/genomics-erectile-dysfunction

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-12-04.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Substantively audited the transcript's scientific claims describing the multi-ancestry ED GWAS, SIM1 locus, ancestry-specific signals, EHR-defined ED, MR, gSEM, correlations with psychiatric/metabolic traits, and drug repurposing implications.
- transcript topics: SIM1 regulatory locus as main ED signal; EUR/AFR/cross-ancestry GWAS results; EHR-defined erectile dysfunction phenotype; Mendelian randomization analyses linking ED to obesity and other traits; Genomic structural equation modeling: two major genetic factors; Gene-level signals (ESR1, CTNNB1, PHF21B, SLC39A8) and TWAS/MAGMA

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- strongest ED genetic signal maps to SIM1 regulatory region on chromosome 6; lead variants rs78677597 (EUR) and rs17185536 (AFR/cross-ancestry)
- 40 lead SNPs in European ancestry; 2 lead SNPs in African ancestry; 51 lead SNPs in cross-ancestry analyses
- EHR-defined ED (EHR-ED) phenotype defined by ICD-10 code N52 or ED drug prescriptions
- Mendelian randomization (MR) shows ED risk variants are a stronger causal factor for morbid obesity than obesity-related ED; bidirectional relations with some traits
- Genomic SEM identifies two major genetic factors: Factor 1 (behavioral/psychiatric) and Factor 3 (metabolic); ED loads on both via co-loading
- Drug repurposing highlights ESR1 antagonists and CTNNB1-related targets; sulindac discussed as PDE5 inhibitor and β-catenin modulator

QC result: Pass.

217: Multiscale triads of meiotic crossover patterning

Gustavo Barra — Wed, 03 Dec 2025 06:19:31 +0000

White MA et al., Nature Communications - FFT and inverse-FFT analysis of Zip3/Zip2, Hop1 and Zip1 on yeast pachytene chromosomes reveals two interdigitated tiers of evenly spaced protein triads that correspond to canonical and minority crossovers and are differentially regulated by Pch2/TRIP13. Key terms: crossover interference, meiotic chromosomes, Zip3/Zip2, Hop1, Pch2.

Study Highlights:
Quantitative fluorescence profiles and Fourier analysis identify two dominant spatial periodicities centered near 0.5 µm and 1.0 µm for Zip3/Zip2, Hop1 and Zip1 along pachytene chromosomes. Inverse FFT reconstructs narrow and broad peaks that colocalize into triads of the three proteins with intra-triad separations of ~70 nm. Shorter-periodicity triads map to canonical Zip3-defined crossovers and show classical interference, while longer-periodicity triads are interdigitated with shorter triads and also exhibit interference. The ratio, spacing relationships, and modulation by Pch2/TRIP13 support the interpretation that longer-periodicity triads correspond to minority crossovers and that Pch2 selectively alters abundance and relative loading in the longer-tier triads

Conclusion:
Crossover interference establishes two interdigitated, multiscale patterns of tightly clustered Zip2/Zip3–Hop1–Zip1 triads along meiotic chromosomes, linking canonical and minority crossovers into a single interference-governed process

Music:
Enjoy the music based on this article at the end of the episode.

First author:
White MA

Journal:
Nature Communications

DOI:
10.1038/s41467-025-65423-6

Reference:
White MA, Weiner B, Chu L, Lim G, Prentiss M & Kleckner N. Crossover interference mediates multiscale patterning along meiotic chromosomes. Nature Communications. 2025;16:10453. https://doi.org/10.1038/s41467-025-65423-6

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/multiscale-crossover-triad-patterning

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-12-03.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript's discussion of the paper's key scientific claims and methods: FFT/IFFT decomposition revealing two periodicities, triad clustering of Zip3-Hop1-Zip1, canonical vs minority crossovers, interdigitation and spacing, CoC/LCoC analyses, and the role of Pch2, including a two-tier sequential model and
- transcript topics: Crossover interference and canonical vs minority crossovers; FFT and inverse-FFT analysis revealing two periodicities; Triad structure of Zip3-Hop1-Zip1 along chromosomes; Interference metrics: CoC and LCoC; Interdigitation of two triad types and precursor spacing (~0.23 μm); Minority crossovers and their ratio to canonical crossovers (~0.46:1)

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Two interdigitated patterns with shorter (~0.5 μm) and longer (~1 μm) periodicities for crossover-related components
- Triplet (triad) clustering of Zip3, Hop1, Zip1 at periodicities (≈0.5 μm and ≈1 μm)
- Shorter periodicity triads correspond to canonical crossovers with strong interference (CoC/LCoC values similar to canonical crossovers)
- Longer periodicity triads correspond to minority crossovers with strong interference and interdigitation with shorter triads
- Inter-triad distance between long and short triads ≈0.27 μm; nearest precursor site spacing ≈0.23 μm
- Ratio of longer to shorter periodicity triads and their relation to minority vs canonical crossovers ≈0.5:1; minority/canonical crossover ratio ≈0.46:1

QC result: Pass.

216: 53BP1-RIF1 and DNA-PKcs: distinct interactions in chromosomal break repair

Gustavo Barra — Tue, 02 Dec 2025 09:45:40 +0000

Makins K et al., Nature Communications - This episode reviews a study showing that 53BP1-RIF1 and DNA-PKcs have different genetic relationships across blunt end joining, deletion patterns, HDR, and radiosensitivity. Key terms: 53BP1, DNA-PKcs, RIF1, non-homologous end joining, microhomology.

Study Highlights:
Using EJ7-GFP and MA-del reporters in HEK293 cells, loss of 53BP1 alone did not reduce blunt No Indel EJ but amplified the decrease caused by DNA-PKcs kinase inhibition (M3814) or PRKDC knockout. Disruption of 53BP1 or RIF1, and DNA-PKcs inhibition or loss, each caused a similar shift toward deletions with increased microhomology and reduced non-microhomology deletions, with combined disruption not additive. 53BP1 loss reduced blunt EJ efficiency in XLF-deficient cells and the deletion pattern of the 53BP1/XLF double mutant resembled that of 53BP1 loss alone. DNA-PKcs kinase inhibition produced marked increases in HDR and radiosensitivity that differed from genetic DNA-PKcs loss and were not fully additive with 53BP1 or RIF1 loss.

Conclusion:
53BP1-RIF1 act as a backup to DNA-PKcs for blunt DSB end joining but function in the same pathway as DNA-PKcs to limit microhomology-mediated deletions, while DNA-PKcs kinase inhibition broadly perturbs repair outcomes and increases radiosensitivity

Music:
Enjoy the music based on this article at the end of the episode.

First author:
Makins K

Journal:
Nature Communications

DOI:
10.1038/s41467-025-65329-3

Reference:
Makins K, Cisneros-Aguirre M, Lopezcolorado FW & Stark JM. 53BP1-RIF1 and DNA-PKcs show distinct genetic interactions with diverse chromosomal break repair outcomes. Nature Communications. 2025;16:10361. https://doi.org/10.1038/s41467-025-65329-3

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/53bp1-rif1-dna-pkcs

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-12-02.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript sections describing (a) the interplay between 53BP1-RIF1 and DNA-PKcs in blunt end joining, (b) deletion/microhomology patterns (MA-del and related assays), (c) HDR and radiosensitivity outcomes (LMNA-HDR and clonogenic assays), (d) role of XLF and RIF1 as context modifiers, and (e) comparisons b
- transcript topics: EJ7-GFP No Indel EJ assay and 53BP1/DNA-PKcs interaction; MA-del assay: deletion patterns and microhomology usage; HDR frequency via LMNA-HDR assay; Radiosensitivity and clonogenic survival after IR; Roles of 53BP1, RIF1, XLF in end-joining and synapsis; DNA-PKcs kinase inhibition vs genetic loss

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 3
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- 53BP1-RIF1 acts as a backup to DNA-PKcs for blunt DSB end joining (NHEJ).
- Disruption of 53BP1 or RIF1 increases microhomology-mediated deletions; combined disruption with DNA-PKcs disruption is not additive for this outcome.
- DNA-PKcs kinase inhibition (M3814) produces larger shifts in repair outcomes (HDR increases and radiosensitivity) than genetic loss of DNA-PKcs.
- HDR frequency increases with 53BP1 loss in DNA-PKcs-proficient cells; M3814 treatment also increases HDR; combined perturbations show context-dependent effects.
- XLF interacts with 53BP1 in promoting end-joining; 53BP1 loss can reduce blunt EJ in XLF-deficient cells.
- RIF1 loss mirrors 53BP1 loss in several microhomology deletion patterns and its effects become pronounced under DNA-PKcs inhibition.

QC result: Pass.

215: Protein Set Transformer for high-diversity viromics

Gustavo Barra — Mon, 01 Dec 2025 09:46:19 +0000

Martin et al., Nat Commun (2025) - Protein Set Transformer (PST) is a protein-based genome language model that represents genomes as sets of proteins to improve genome and protein representations across diverse viral datasets. Key terms: viromics, protein-language-model, genome-embeddings, triplet-loss, host-prediction.

Study Highlights:
PST embeds proteins with ESM2, concatenates positional and strand vectors, contextualizes proteins with a multi-head attention encoder, and produces genome embeddings via a learnable weighted decoder pooling. The foundation PST-TL models were pretrained on >100k dereplicated viral genomes encoding >6M proteins using a triplet-loss objective with PointSwap augmentation and evaluated on IMG/VR v4 and MGnify soil virus test sets. PST-TL outperformed other protein- and nucleotide-based methods at recovering genome–genome relationships, including remote relationships, and its protein embeddings clustered structural capsid folds and late-gene functional modules. PST improved annotation transfer for hypothetical proteins via embedding and structure-aware clustering and boosted viral host-species prediction when used in a graph link-prediction framework.

Conclusion:
PST provides transferable genome- and protein-level embeddings that strengthen representation, annotation, and host-prediction tasks for diverse viral and microbial genomics applications

Music:
Enjoy the music based on this article at the end of the episode.

First author:
Martin

Journal:
Nat Commun (2025)

DOI:
10.1038/s41467-025-66049-4

Reference:
Martin, C., Gitter, A., Anantharaman, K. Protein Set Transformer: a protein-based genome language model to power high-diversity viromics. Nat Commun (2025). https://doi.org/10.1038/s41467-025-66049-4

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/protein-set-transformer

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-12-01.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Substantive audit of the core scientific claims and results described in PST工作 (architecture, training, data, evaluation, functional insights, host prediction, generalizability, and biosafety/licensing) as presented in the transcript.
- transcript topics: PST architecture: genome modeled as set of proteins with context; Protein embeddings and genome-position/strand augmentation; Triplet loss training: Chamfer distance and PointSwap; Pretraining data scale: >100k viral genomes, >6M proteins; Performance: PST-TL outperforms PST-CTX and PST-MLM; Remote relation detection: ASI correlations with PST embeddings

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Genomes are modeled as sets of proteins with context (not as linear sequences)
- ESM2 protein embeddings are augmented with two learnable vectors representing protein position and coding strand
- Training uses triplet loss with Chamfer distance and PointSwap augmentation

Chapters

(00:00:00) - Deep Learning in Viral Biology
(00:02:31) - Preliminary insights into viral biology
(00:08:01) - PSTTL: The Hidden Genome of Viruses
(00:11:29) - PSTTL: The Virality Model
(00:14:22) - Preston 2, Context-aware viral evolution
(00:16:19) - Signs and Numbers in the Code

214: PI(4,5)P2 Asymmetry Accelerates FGF2 Secretion

Gustavo Barra — Sun, 30 Nov 2025 12:08:06 +0000

Kaur M et al., Nature Communications - Reconstitution of asymmetric membranes and matched cell experiments show that transbilayer asymmetry of PI(4,5)P2 lowers the energetic barrier for FGF2-driven lipidic pore formation and enables rapid unconventional secretion. Disrupting PI(4,5)P2 asymmetry in cells blocks FGF2 export. Key terms: FGF2, PI(4,5)P2, membrane asymmetry, unconventional secretion, lipidic pore.

Study Highlights:
The authors created asymmetric LUVs and GUVs by enzymatic conversion of outer-leaflet PI(4)P to PI(4,5)P2 using PIP5K1C. Time-lapse GUV assays showed that PI(4,5)P2 asymmetry accelerated FGF2-dependent lipidic pore formation (mean ≈45 min asymmetric vs ≈95 min symmetric). In CHO-K1 cells, delivering PI(4,5)P2 to the outer leaflet to disturb asymmetry prevented reappearance of surface FGF2-GFP after heparin wash. Addition of other FGF2-binding phosphoinositides (PI(3,4)P2, PI(3,4,5)P3) similarly inhibited secretion, while PI(4)P and PS did not.

Conclusion:
Transbilayer asymmetry of PI(4,5)P2 is a key biophysical determinant that facilitates FGF2 oligomer–dependent lipidic pore formation and efficient unconventional secretion.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Plasma membrane transbilayer asymmetry of PI(4,5)P2 drives unconventional secretion of Fibroblast Growth Factor 2

First author:
Kaur M

Journal:
Nature Communications

DOI:
10.1038/s41467-025-66860-z

Reference:
Kaur M, Lolicato F, Nickel W. Plasma membrane transbilayer asymmetry of PI(4,5)P2 drives unconventional secretion of Fibroblast Growth Factor 2. Nat Commun (2025). https://doi.org/10.1038/s41467-025-66860-z

License:
Creative Commons Attribution 4.0 International (CC BY 4.0)

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/pi45p2-asymmetry-drives-fgf2-secretion

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-11-30.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript's coverage of PI(4,5)P2 transbilayer asymmetry driving FGF2 secretion, including in vitro asymmetric membranes (LUVs/GUVs), kinase-driven outer-leaflet PI(4,5)P2 generation, cell-based disruption of asymmetry and secretion, lipid controls, kinetics, and recovery dynamics.
- transcript topics: FGF2 unconventional secretion overview; PI(4,5)P2 transbilayer asymmetry concept; In vitro reconstitution with asymmetric LUVs/GUVs; PIP5K1C-mediated outer-leaflet PI(4,5)P2 generation and asymmetry verification; Kinetics of FGF2 pore formation in asymmetric vs symmetric membranes; Cell-based disruption of PI(4,5)P2 asymmetry and impact on FGF2 secretion

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Core mechanism: PI(4,5)P2 transbilayer asymmetry lowers energy barrier for FGF2 membrane pore formation.
- In vitro, asymmetric PI(4,5)P2 on outer leaflet accelerates pore formation (GUVs) compared with symmetric membranes.
- Cell-based disruption of PI(4,5)P2 asymmetry inhibits FGF2 secretion.
- Controls show PS and PI(4)P do not inhibit secretion; PI(3,4)P2 and PI(3,4,5)P3 do inhibit secretion.
- G...

Chapters

(00:00:00) - Deep Dive: The physics of cell secretions
(00:02:46) - How FGF2 secreates from the cell
(00:07:02) - Immunity 7, Asymmetry blocks FGF2 secretion
(00:10:24) - What is it about PI4.5p that lowers the energy
(00:13:39) - How to Find Your Way Through the Night

213: BRAIN-MAGNET: Functional genomics atlas for non-coding variants

Gustavo Barra — Sat, 29 Nov 2025 12:10:55 +0000

Deng R et al. - BRAIN-MAGNET couples a ChIP-STARR-seq atlas of 148,198 neural regulatory elements with a validated convolutional neural network to predict enhancer activity and prioritize disease-relevant non-coding variants. Key terms: enhancers, neural stem cells, convolutional neural network, non-coding variants, functional genomics.

Study Highlights:
The authors generated an activity-ranked functional genomics atlas of 148,198 non-coding regulatory elements in human neural stem cells. Comparative ChIP-STARR-seq revealed many elements are epigenetically primed in embryonic stem cells for later neural activity. BRAIN-MAGNET, a convolutional neural network trained on the atlas, predicts enhancer activity from DNA sequence and computes nucleotide-level contribution scores to identify functional motifs. The model outperformed other prioritization scores at tested loci and enabled prioritization and functional validation of both common GWAS SNPs and rare variants, including a putative RAB7A enhanceropathy.

Conclusion:
The NCRE atlas and BRAIN-MAGNET provide a functionally validated resource to interpret non-coding genetic variation relevant to neurodevelopment and neurological disease

Music:
Enjoy the music based on this article at the end of the episode.

First author:
Deng R

DOI:
10.1016/j.cell.2025.10.029

Reference:
Deng R, Perenthaler E, Nikoncuk A, Yousefi S, Lanko K, Schot R, Maresca M, Medico-Salsench E, Sanderson LE, Parker MJ, van Ijcken WFJ, Park J, Sturm M, Haack TB, Roshchupkin GV, Mulugeta E, Barakat TS. BRAIN-MAGNET: A functional genomics atlas for interpretation of non-coding variants. Cell. 2026 Jan 22;189:1–20. https://doi.org/10.1016/j.cell.2025.10.029

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/brain-magnet-ncre-atlas

️ Episode:
213: Episode 213: BRAIN-MAGNET: a functional atlas for non-coding variants

️ Season:
1

Article title:
BRAIN-MAGNET: A functional genomics atlas for interpretation of non-coding variants

Journal:
Cell

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-11-29.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited core scientific content: NSC-ChIP-STARR-seq atlas, Brain-Magnet model with nucleotide-level contribution scores, ESC–NSC enhancer priming, motif and TE enrichments, motif deletions/validation, RAB7A enhanceropathy, GWAS/rare-disease variant prioritization, and limitations of episomal MPRA.
- transcript topics: NSC-ChIP-STARR-seq atlas of non-coding regulatory elements; Brain-Magnet CNN and nucleotide-level contribution scores; Primed enhancers and ESC-to-NSC differentiation; Motif and transposable element enrichment (YY1, TP53/p53, MER61, LTR10); Functional validation of high cb-score motifs (30 bp deletions, point mutations); RAB7A enhanceropathy and in vivo validation

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- ChIP-STARR-seq NSCs produced an atlas of ~148,000 NCREs with top-10% activity category.
- BRAIN-MAGNET predicts NCRE activity from DNA sequence and outputs per-nucleotide cb scores.
- Highly active NCREs link to higher target gene expression and LoF-intolerant (pLI) genes.
- NCREs show ESCs-primed enhancer status, with priming markers (H3K4me2/3) preceding NSC activation.
- High cb-score motifs (e.g., TP53/TP73/YY1) and TE enrichments (MER61, LTR10) observed in NSCs.
- Functional validation: deleting high-cb motifs in 16/17 NCREs reduces activity; low-cb regions show little/no effect.

QC result: Pass.

212: Zonal control of mutant β-catenin tumorigenesis

Gustavo Barra — Fri, 28 Nov 2025 09:58:21 +0000

Raven A et al. - This study shows that hepatic zonation determines whether mutant β-catenin drives proliferation and liver cancer by forcing differentiation to a non-permissive zone 3 fate or, when reversed, enabling MAPK- and mTOR-dependent growth. Key terms: hepatic zonation, beta-catenin, MYC, mTOR, IGFBP2.

Study Highlights:
β-catenin exon 3 mutations cooperate with exogenous MYC to produce a proliferative translatome that supports tumour outgrowth. Differentiation to an extreme zone 3 GLUL+Lgr5+ hepatocyte fate suppresses the pro-growth translatome and is refractory to WNT/MYC-driven tumorigenesis. Early proliferative lesions that progress show reduced WNT activation, elevated MAPK signalling and engagement of an IGFBP2–mTOR–cyclin D1 axis, and inhibition of IGFBP2, mTOR or Yap/Taz impairs lesion formation and tumorigenesis. High-level WNT activation from Apc loss is less compatible with tumour formation, whereas MAPK activation (BrafV600E) antagonizes zone 3 differentiation to permit Lgr5+ hepatocyte transformation that can be suppressed by PORCN or BRAF inhibitors

Conclusion:
Hepatocyte zonal identity dictates susceptibility to WNT-driven HCC, and escape from WNT-induced zone 3 differentiation plus activation of MAPK/mTOR pro-growth pathways is required for tumour initiation

Music:
Enjoy the music based on this article at the end of the episode.

First author:
Raven A

DOI:
10.1038/s41586-025-09733-1

Reference:
Raven A. et al. Hepatic zonation determines tumorigenic potential of mutant β-catenin. Nature. 2025. https://doi.org/10.1038/s41586-025-09733-1

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/hepatic-zonation-wnt-tumorigenesis

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-11-28.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the main scientific narrative in the transcript: hepatic zonation, CTNNB1 mutations and MYC cooperation, zone 3 differentiation as tumor suppressor, the IGFBP2–mTOR–CCND1 axis, MAPK signaling and BRAF involvement, and pharmacological proof-of-concept (rapamycin, dabrafenib, LGK974).
- transcript topics: Hepatic zonation and WNT signaling; CTNNB1 exon 3 mutations and MYC cooperation; Zone 3 differentiation as tumor suppressor and zone 2 growth axis; IGFBP2–mTOR–CCND1 pro-growth axis; MAPK signaling and BRAF involvement in tumorigenesis; Ribosome profiling and translational control

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 5
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- CTNNB1 exon 3 mutations cooperate with MYC to drive a proliferative translatome
- 81% of CTNNB1-mutated tumors exhibit MYC copy-number gain
- Zone 3 GLUL+ Lgr5+ hepatocytes are refractory to WNT- and MYC-driven tumorigenesis
- Early proliferative lesions show reduced WNT activation and elevated MAPK signaling
- IGFBP2–mTOR–CCND1 axis supports lesion growth; IGFBP2/mTOR inhibition reduces tumorigenesis
- Rapamycin reduces lesion number and extends survival in mouse m...

Chapters

(00:00:00) - Base by Bass
(00:02:20) - Hepatic zonation 6, The liver paradox
(00:03:35) - How does wnt signaling cause cancer?
(00:06:28) - WNT mutations in the liver

211: Retention Elements in Cancer Cells

Gustavo Barra — Thu, 27 Nov 2025 10:24:31 +0000

Sankar et al. - This episode explores the discovery of genetic elements that promote the retention of extrachromosomal DNA (ecDNA) in cancer cells, enhancing their survival and evolution. Key terms: ecDNA, retention elements, cancer cells, genomic elements, oncogenes.

Study Highlights:
Researchers identified a family of genomic elements known as retention elements that tether ecDNA to mitotic chromosomes, facilitating its transmission to daughter cells during division. The study utilized a novel genome-scale assay called Retain-seq, revealing thousands of retention elements that enhance the persistence of ecDNA. These elements are primarily located at gene promoters and are characterized by high CpG density, which is crucial for their function. The findings suggest that retention elements play a significant role in the maintenance of oncogenic ecDNA across generations of cancer cells.

Conclusion:
Understanding the mechanisms of ecDNA retention may provide insights into cancer evolution and potential therapeutic targets.

Music:
Enjoy the music based on this article at the end of the episode.

First author:
Sankar

DOI:
10.1038/s41586-025-09764-8

Reference:
Sankar, V., Hung, K. L., Gnanasekar, A., Wong, I. T.-L., Shi, Q., Kraft, K., Jones, M. G., He, B. J., Yan, X., Belk, J. A., Liu, K. J., Agarwal, S., Wang, S. K., Henssen, A. G., Mischel, P. S., & Chang, H. Y. (2025). Genetic elements promote retention of extrachromosomal DNA in cancer cells. Nature. https://doi.org/10.1038/s41586-025-09764-8

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/retention-elements-cancer

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-11-27.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript sections describing Retain-seq, identification and features of retention elements, tethering mechanism to mitotic chromosomes via bookmarking, promoter/enhancer-like interactions, epigenetic regulation (CpG methylation and CRISPRoff), and tumor-data implications; cross-checked these against the a
- transcript topics: ecDNA and mitotic inheritance; Retain-seq methodology and discovery of retention elements; Sequence features of retention elements (CpG-rich promoters, active chromatin); Retention element tethering to mitotic chromosomes via mitotic bookmarking; Promoter–enhancer-like interactions recapitulated in trans; Additive effect of multiple retention elements on retention

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Retention elements are a family of human genomic elements that tether episomes to mitotic chromosomes to promote ecDNA transmission
- Retain-seq identifies thousands of retention elements across the genome
- Retention elements are CpG-rich promoters and active regulatory regions associated with active chromatin
- Retention elements tether to chromosomes at mitotically bookmarked regions, recapitulating promoter–enhancer interactions a...

Chapters

(00:00:00) - How does rogue DNA stay in cancer cells?
(00:02:36) - Cancer DNA: The retention mechanism
(00:07:29) - Cancer epigenetic retention elements
(00:12:47) - Circles that refuse to fall: the cancer drug strategy

210: Tumour-Reactive CD8 T Cell Clusters in Human Melanoma

Gustavo Barra — Wed, 26 Nov 2025 10:03:48 +0000

Tumour-Reactive CD8 T Cell Clusters in Human Melanoma

Music:
Enjoy the music based on this article at the end of the episode.

DOI:
10.1038/s41586-025-09754-w

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/tumour-reactive-cd8-t-cell-clusters-in-human-melanoma

️ Episode:
210: Tumour-Reactive CD8 T Cell Clusters in Human Melanoma

️ Season:
1

Article title:
Tumour-reactive heterotypic CD8 T cell clusters from clinical samples

Journal:
Nature

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-11-26.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited transcript sections covering cluster discovery, immunological synapse evidence, antigen-specific competition, ex vivo cytotoxicity and cytokine production, in vivo ACT/PDX results, and the TCF7+ stem-like exhausted T cell state.
- transcript topics: Immunological synapse and proximity requirements; Preservation of cellular clusters during tissue processing; Antigen-specific T cell competitiveness and cluster formation; Clinical heterotypic CD8+ T cell clusters in melanoma (21 samples); Single-cell RNA/TCR analyses of cluster T cells; Ex vivo cytotoxicity and cytokine production by cluster-derived T cells

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- 21 melanoma metastases analyzed; heterotypic CD8+ T cell clusters with tumor cells and/or APCs observed in all samples
- Clusters show relocalization of immune synapse markers (HLA-ABC, CD58, ICAM1) to the T cell–tumor interface
- MART-1-specific T cells outcompete non-specific T cells for cluster formation; up to 11-fold enrichment at 1% input
- Ex vivo killing by cluster-derived T cells is ~9-fold higher than singlets; increased IFN-γ and TNF production
- In vivo ACT/PDX models show tumor control and increased T cell infiltration/activation with cluster-derived T cells
- Clustered CD8+ T cells show a TCF7+ stem-like exhausted state associated with persistence and durability

QC result: Pass.

Chapters

(00:00:00) - The Paradox of the Immune System
(00:02:31) - Immunity clusters in melanoma
(00:08:13) - Immunity 4, Cluster-derived T cells
(00:11:45) - Cluster Analysis for T-cell protection
(00:14:52) - Crowded Storms

209: PERT: Prime Editing tRNAs for Nonsense Mutations

Gustavo Barra — Tue, 25 Nov 2025 15:07:00 +0000

PERT: Prime Editing tRNAs for Nonsense Mutations

Music:
Enjoy the music based on this article at the end of the episode.

DOI:
10.1038/s41586-025-09732-2

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/pert-prime-editing-trnas-for-nonsense-mutations

️ Episode:
209: PERT: Prime Editing tRNAs for Nonsense Mutations

️ Season:
1

Article title:
Prime editing-installed suppressor tRNAs for disease-agnostic genome editing

Journal:
Nature

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-11-25.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Substantively audited the central scientific narrative: PERT concept and single-locus sup-tRNA installation; cell-model rescues in Batten/Tay-Sachs/NPC1; ClinVar PTC readthrough breadth; in vivo GFP reporter readthrough; Hurler mouse model IDUA restoration and pathology rescue; safety/off-target and delivery considerat
- transcript topics: Disease-agnostic genome editing concept (PERT); Sup-tRNA optimization and design (leader, body, terminator); Single-locus endogenous tRNA installation via prime editing; Cell-model rescues: Batten (TPP1), Tay-Sachs (HEXA), NPC1; ClinVar PTC readthrough across 14,746 mutations; In vivo GFP reporter readthrough and Hurler syndrome mouse model

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- PERT installs an engineered sup-tRNA at a single endogenous genomic locus to enable readthrough of premature termination codons (PTCs).
- In human cell models of Batten (TPP1), Tay–Sachs (HEXA), and Niemann–Pick (NPC1) diseases, treatment with the same prime editor components restored 20–70% of normal enzyme activity
- In a Hurler syndrome mouse model, IDUA enzyme activity was restored ~6% and disease pathology was nearly completely rescued.
- Across ClinVar PTCs (14,746 tested), readthrough was observed for the vast majority, with an average readthrough score of 69% ± 30%.
- Mass spectrometry indicated no detectable readthrough of natural termination codons (NTCs) and no broad perturbations to the transcriptome or proteome.
- In vivo GFP reporter readthrough in a reporter mouse was around 25% full-length GFP production with the PERT approach.

QC result: Pass.

Chapters

(00:00:00) - Genetic precision medicine: The single treatment for thousands of diseases
(00:04:27) - Percetic Prime Editing
(00:09:54) - PERT for CF-19
(00:12:45) - One Code for Many Stars

208: ZAK, Collided Ribosomes, and the Stress Switch

Gustavo Barra — Mon, 24 Nov 2025 09:34:28 +0000

ZAK, Collided Ribosomes, and the Stress Switch

Music:
Enjoy the music based on this article at the end of the episode.

DOI:
10.1038/s41586-025-09772-8

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/zak-collided-ribosomes-and-the-stress-switch

️ Episode:
208: ZAK, Collided Ribosomes, and the Stress Switch

️ Season:
1

Article title:
ZAK activation at the collided ribosome

Journal:
Nature

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-11-24.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited sections covering ZAK constitutive ribosome binding, collision sensing via RACK1, RIH and RIM motifs, SAM-domain dimerization as activation switch, SERBP1 regulation, CLIP-seq mapping to ES7/ES6b/c, and downstream MAPK signaling.
- transcript topics: RSR overview and ZAK as central kinase; Constitutive ribosome binding of ZAK to the 40S via pin and ES7-patch; Collision interface: RACK1, RIH, and RIM motifs; SAM-domain dimerization as activation switch; SERBP1 competition at FPxL motif on RACK1; CLIP-seq mapping ES7 and ES6b/c on 18S rRNA

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- ZAK activation is triggered by ribosome collisions via SAM-domain dimerization at the collision interface.
- RACK1 acts as the collision scaffold bridging ZAK to both collided ribosomes, with ZAK interacting through RIH and RIM motifs.
- RIH anchors ZAK to RACK1 and is necessary for binding and activation.
- FPxL motif (RIM) is strictly required for ZAK activation on collided ribosomes, but not for initial binding.
- SERBP1 competes for the RACK1 FPxL binding site and acts as a negative regulator of ZAK activation.
- ZAK pin (eS27-pin) anchors ZAK to the 40S subunit via W768; ES7-patch also contributes to ribosome binding.

QC result: Pass.

Chapters

(00:00:00) - The cell's ribotoxic stress response
(00:05:10) - The Rack 1 Collapse Sensor
(00:09:55) - How does the ZK SAM domains dimerize to trigger cell
(00:12:16) - When We Collide

207: Semantic Design of de novo Genes with Evo

Gustavo Barra — Mon, 24 Nov 2025 02:00:11 +0000

Semantic Design of de novo Genes with Evo

Music:
Enjoy the music based on this article at the end of the episode.

DOI:
10.1038/s41586-025-09749-7

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/semantic-design-of-de-novo-genes-with-evo

️ Episode:
207: Semantic Design of de novo Genes with Evo

️ Season:
1

Article title:
Semantic design of functional de novo genes from a genomic language model

Journal:
Nature

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-11-24.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited transcript sections describing Evo 1.5 semantic design, contextual autocompletion, toxin–antitoxin designs (T2TA/T3TA), anti-CRISPR designs, and SynGenome, plus limitations and licensing statements.
- transcript topics: Semantic design and genomic context; In-context design and autoregression; Toxin–antitoxin (T2TA) design and validation; Toxin–antitoxin (T3TA) design and validation; Anti-CRISPR (Acr) design and validation; SynGenome database and analyses

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Semantic design uses genomic context to enable function-guided design of de novo genes (Evo 1.5).
- Autocomplete test: Evo 1.5 achieved 85% amino acid recovery for rpoS with 30% input.
- Toxin–antitoxin (T2TA) design yielded functional toxins and antitoxins; EvoRelE1 toxin; EvoAT1–4 antitoxins; EvoAT2 and EvoAT4 show multitoxin neutralization; EvoT3TA design produc
- Anti-CRISPR (Acr) designs produced functional Acrs; 17% of tested Acrs exhibited activity against SpCas9; EvoAcr1–5 validated.
- SynGenome database contains over 120 billion base pairs of AI-generated DNA; ~3.7 million predicted protein structures; Pfam-domain frequencies in SynGenome closely mirror natural
- Limitations include autoregressive generation risks (repetitive/hallucinated sequences) and reliance on genomic context; lab validation remains essential; applicability to human ge

QC result: Pass.

Chapters

(00:00:00) - A New Way to Design New Genomes
(00:05:45) - Artificial Intelligence's challenge to protein design
(00:11:08) - Uncovering the genome's hidden secrets
(00:11:53) - The Secret Life of Genes

206: Wild Birds and the North American H5N1 Epizootic

Gustavo Barra — Sat, 22 Nov 2025 12:06:31 +0000

Wild Birds and the North American H5N1 Epizootic

Music:
Enjoy the music based on this article at the end of the episode.

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/wild-birds-and-the-north-american-h5n1-epizootic

️ Episode:
206: Wild Birds and the North American H5N1 Epizootic

️ Season:
1

Article title:
Ecology and spread of the North American H5N1 epizootic

Journal:
Nature

DOI:
10.1038/s41586-025-09737-x

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-11-22.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited substantive narrative segments: introduction to North American H5N1 epizootic, phylogeographic analysis and introductions, flyway diffusion, canonical vs non-canonical hosts, backyard vs commercial spillovers, and surveillance/limitations.
- transcript topics: Introduction and scope of North American H5N1 epizootic; Phylogeographic analysis and number of introductions; Flyway diffusion across Atlantic, Mississippi, Central, and Pacific; Canonical hosts (Anseriformes) vs non-canonical hosts; Persistence times in wild vs domestic birds; Spillovers to backyard/commercial birds and their implications

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Nine introductions into North America from Europe/Asia
- Anseriformes drive transmission; non-canonical hosts are largely dead-ends
- 46–113 independent introductions into domestic birds from wild birds
- Backyard birds infected about 9.6 days earlier than commercial poultry
- Farm-to-farm transmission is a minor component; wild-bird introductions drive spillovers
- Wild birds are the main engine; enhanced wild-bird surveillance is key

QC result: Pass.

Chapters

(00:00:00) - North American bird flu: The genetics of the virus
(00:04:03) - The map of bird flu spreads
(00:06:07) - How Did the Zika virus get to North America?
(00:09:09) - H5N1 spillover into poultry operations
(00:14:07) - Signals on the Flyways

205: Ancient RNA Expression Profiles from the Woolly Mammoth

Gustavo Barra — Fri, 21 Nov 2025 10:44:00 +0000

Ancient RNA Expression Profiles from the Woolly Mammoth

Music:
Enjoy the music based on this article at the end of the episode.

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/ancient-rna-expression-profiles-from-the-woolly-mammoth

️ Episode:
205: Ancient RNA Expression Profiles from the Woolly Mammoth

️ Season:
1

Article title:
Ancient RNA Expression Profiles from the Woolly Mammoth

Journal:
Cell

DOI:
10.1016/j.cell.2025.10.025

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-11-21.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript's coverage of the article’s main experimental design, data-quality checks, major results, tissue-level interpretation, and preservation rationale, including sample collection/preservation, RNA sequencing and fragment mapping, damage signatures, exonic reads, tissue identity, sex determination, an
- transcript topics: Sample collection and permafrost preservation; RNA sequencing, fragment length, and mapping strategy; Damage signatures and data authenticity (CU deamination, 5' end bias); Exonic mapping and exon-exon junctions indicating mature mRNA; Tissue identity and metabolism (skeletal muscle; slow-twitch markers MYH7, TNNT1, NEB); Genetic sex determination (Y-chromosome transcripts USP9Y) and autosomal DNA

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- RNA recovered from soft tissues of woolly mammoths; 3 of 10 samples showed endogenous mammoth material
- RNA fragments map to exonic regions and span exon-exon junctions, indicating mature mRNA
- Tissue expression profile matches skeletal muscle with slow-twitch fiber markers (MYH7, TNNT1, NEB)
- Genetic sex determined as male via Y-chromosome transcripts such as USP9Y
- Two novel mammoth-specific microRNAs predicted (MPR novel 4 and MPR novel 5) in Afrotherians
- Mir-1 variant with GG unpaired bulge observed, shared among Proboscidians

QC result: Pass.

204: StealTHY CRISPR: Revealing Hidden Metastasis Regulators

Gustavo Barra — Thu, 20 Nov 2025 10:39:51 +0000

StealTHY CRISPR: Revealing Hidden Metastasis Regulators

Music:
Enjoy the music based on this article at the end of the episode.

License:
CC BY 4.0 International License (CC BY 4.0)

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/stealthy-crispr-revealing-hidden-metastasis-regulators

️ Episode:
204: StealTHY CRISPR: Revealing Hidden Metastasis Regulators

️ Season:
1

Article title:
Stealthy CRISPR: Revealing Hidden Metastasis Regulators

Journal:
Cell

DOI:
10.1016/j.cell.2025.10.007

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-11-20.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited transcript sections describing stealth platform design, immunogenicity challenges in vivo, iatrogenic clonal dropout, Harakiri purification, AMHR2 axis as a metastasis driver, and translational relevance via TCGA.
- transcript topics: CRISPR immunogenicity in vivo and iatrogenic clonal dropout; Stealth platform design: immune stealth reporters, autologous reporters, Hit-and-Run Cas9; Harakiri selection and ex vivo purification; Preservation of sgRNA library diversity in immunocompetent models; AMHR2 axis as metastasis driver; Dominant negative AMHR2 decoy receptor therapy in humanized/PDX models

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Stealth CRISPR platform uses immune stealth reporters, HiT-and-Run Cas9 delivery, and Harakiri selection to render CRISPR screens immunologically inert
- In immunocompetent models, stealth platform preserves clonal diversity and full sgRNA library integrity
- AMHR2 axis identified as a major driver of metastasis; knockout yields a 20-fold reduction in metastases
- Dominant negative AMHR2 decoy receptor suppresses tumor volume by >80% and essentially abolishes metastasis in humanized/PDX models
- Blocking AMHR2 signaling shifts tumor immune microenvironment: reduced Tregs, increased activated macrophages and cytotoxic T cells; Type I interferon genes and STAT1 pathway upreg
- Human relevance supported via TCGA data showing high AMH expression correlates with poor prognosis in breast cancer

QC result: Pass.

203: Divergent Evolutionary Dynamics of Benign and Malignant Tumors

Gustavo Barra — Wed, 19 Nov 2025 20:24:00 +0000

Divergent Evolutionary Dynamics of Benign and Malignant Tumors

Music:
Enjoy the music based on this article at the end of the episode.

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/divergent-evolutionary-dynamics-of-benign-and-malignant-tumors

️ Episode:
203: Divergent Evolutionary Dynamics of Benign and Malignant Tumors

️ Season:
1

Article title:
Divergent Evolutionary Dynamics of Benign and Malignant Tumors

Journal:
Proceedings of the National Academy of Sciences

DOI:
10.1073/pnas.2519203122

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-11-19.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript portions that present the main comparative oncology findings: definitions of benign vs malignant tumors, the body-mass association, pathwise rate effects, diversification-rate effects, MPGLMM methodology, bird vs mammal differences, genome-architecture implications, and broader implications.
- transcript topics: Benign vs malignant tumor definitions; Body mass and tumor prevalence; Pathwise rate of body size evolution; Diversification rate and tumor prevalence; MPGLMM methodology; Birds vs mammals results

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Both benign and malignant tumor prevalence increase with body mass across birds and mammals.
- Malignant tumor prevalence is negatively associated with the pathwise rate of body size evolution.
- Benign tumor prevalence shows no significant association with the pathwise rate of body size evolution.
- Diversification rate is positively associated with tumor prevalence in birds for both tumor types; no significant association in mammals.
- Bird genome architecture (smaller, more compact genomes) may underlie the observed divergence via genomic instability and chromosomal rearrangements.
- Overall divergence: malignant tumors are constrained by body-size evolution; benign tumors persist with less constraint; distinct macroevolutionary drivers for each tumor type.

QC result: Pass.

202: Stereo-seq V2: Spatial Total RNA Mapping in FFPE Tissues

Gustavo Barra — Wed, 19 Nov 2025 06:45:12 +0000

Stereo-seq V2: Spatial Total RNA Mapping in FFPE Tissues

Music:
Enjoy the music based on this article at the end of the episode.

License:
CC BY 4.0 International License (CC BY 4.0)

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/stereo-seq-v2-spatial-total-rna-mapping-in-ffpe-tissues

️ Episode:
202: Stereo-seq V2: Spatial Total RNA Mapping in FFPE Tissues

️ Season:
1

Article title:
Stereo-Seq V2: Spatial Total RNA Mapping in FFPE Tissues

Journal:
Cell

DOI:
10.1016/j.cell.2025.08.008

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-11-19.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited transcript sections describing FFPE RNA degradation and cross-linking, random-priming with 6N primers, uniform gene-body coverage and 3' bias elimination, 500 nm DNA nano-ball (DNB) arrays for subcellular spatial resolution, total RNA mapping including non-polyadenylated RNAs, DV200 tolerance, and applications
- transcript topics: FFPE RNA degradation and formaldehyde cross-linking; Random-priming with 6N primers vs poly-A capture; Uniform gene-body coverage and 3' bias elimination; DNA nano-ball (DNB) arrays at 500 nm spacing for subcellular resolution; Total RNA mapping including non-polyadenylated RNAs; DV200 tolerance in aged FFPE samples

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Stereo-Seq V2 uses random primers (6N) to capture total RNA from FFPE tissues
- Random priming yields uniform coverage across the entire gene body and removes 3' bias
- Total RNA mapping includes non-polyadenylated RNAs enabling non-coding RNA profiling
- DV200 tolerance: low as 18% in nine-year-old FFPE samples
- Gene detection exceeds poly-A based methods with >23,000 genes missed by poly-A techniques
- Alternative splicing events identified (e.g., GIPC1 exon skipping)

QC result: Pass.

201: Sex, Smoking, and Somatic Selection in the Bladder

Gustavo Barra — Mon, 17 Nov 2025 09:41:00 +0000

Music:
Enjoy the music based on this article at the end of the episode.

DOI:
10.1038/s41586-025-09521-x

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

️ Episode:
201: 201: Sex, Smoking, and Somatic Selection in the Bladder

️ Season:
1

Article title:
Sex and smoking bias in the selection of somatic mutations in human bladder

Journal:
Nature

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-11-17.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited transcript sections covering ultradeep duplex sequencing of normal urothelium, sex- and smoking-associated clonal selection, TERT promoter mutations, FGFR3 negative selection, natural saturation mutagenesis, TP53 site selectivity, and clinical implications.
- transcript topics: Ultradeep duplex sequencing of normal urothelium; Driver mutations and positive selection in 16 bladder genes; Sex bias: RBM10, CDKN1A, ARID1A truncating mutations higher in men; TERT promoter activating mutations associated with age and smoking; TERT promoter mutations promote clonal expansions rather than global mutation density; FGFR3 truncating mutations under negative selection

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Ultradeep sequencing identified thousands of driver mutations across 16 genes in normal urothelium
- Men have significantly more truncating driver mutations in RBM10, CDKN1A, and ARID1A than women
- Activating TERT promoter mutations detected in normal bladder tissue and associated with age and smoking
- TERT promoter mutations promote clonal expansions rather than globally increasing mutation density in smokers
- FGFR3 truncating mutations exhibit negative selection in normal urothelium
- Natural saturation mutagenesis observed in vivo via ultradeep sequencing, with TP53 site selection

QC result: Pass.

200: Sperm Sequencing Reveals Extensive Positive Selection in the Male Germline

Gustavo Barra — Sun, 16 Nov 2025 11:02:52 +0000

Music:
Enjoy the music based on this article at the end of the episode.

DOI:
10.1038/s41586-025-09448-3

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

️ Episode:
200: 200: Sperm Sequencing Reveals Extensive Positive Selection in the Male Germline

️ Season:
1

Article title:
Sperm sequencing reveals extensive positive selection in the male germline

Journal:
Nature

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-11-16.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited transcript sections describing (i) mutation rates in sperm vs blood, (ii) NanoSeq/duplex sequencing methodology and error correction, (iii) positive selection in the male germline including gene count and LOF/activating mechanisms, (iv) RAS–MAPK pathway involvement, (v) disease risk implications and paternal ag
- transcript topics: Sperm mutation rates and somatic comparison; NanoSeq/duplex sequencing methodology and error correction; Positive selection in the male germline: gene count and mutation mechanisms; Loss-of-function vs activating mutations and RAS–MAPK pathway; Disease risk implications and paternal age effects; Study limitations and boundaries of NanoSeq (variant types detected)

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Baseline sperm mutation rate: 1.67 substitutions per year per haploid genome
- Sperm accumulate mutations ~8x slower than in blood
- Number of genes under significant positive selection: 40 (31 newly identified)
- Loss-of-function mutations are common among positively selected genes; many in the RAS–MAPK pathway
- Positive selection drives 2–3x increased risk of disease-causing mutations
- 3–5% of sperm from middle-aged to older individuals carry a pathogenic mutation across the exome

QC result: Pass.

199: PLD4 Deficiency and Lupus: When Nuclease Failure Ignites Autoimmunity

Gustavo Barra — Sat, 15 Nov 2025 10:56:47 +0000

PLD4 Deficiency and Lupus: When Nuclease Failure Ignites Autoimmunity

Music:
Enjoy the music based on this article at the end of the episode.

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/pld4-deficiency-and-lupus-when-nuclease-failure-ignites-autoimmunity

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-11-15.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the core scientific narrative from mutation discovery to mechanistic function, single-cell analyses, mouse model phenotypes, and therapeutic implications.
- transcript topics: PLD4 mutations and monogenic lupus; Endosomal nucleic acid sensing and TLR7/9 signaling; PLD4 exonuclease activity assays; scRNA-seq of patient PBMCs and IFN signatures; CyTOF cytokine profiling in PBMCs; Pld4−/− mice autoimmunity and nephritis

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Five SLE patients with biallelic PLD4 mutations were identified.
- PLD4 functions as a 5′ exonuclease that cleaves ssDNA and ssRNA in endosomes to limit TLR7/9 signaling.
- Mutations in PLD4 impair exonuclease activity in vitro (loss of catalytic function observed for patient-derived variants).
- scRNA-seq and CyTOF show IFN/TLR pathway activation predominantly in dendritic cells and monocytes.
- Pld4−/− mice display autoimmunity and nephritis with expansion of plasmacytoid dendritic cells (pDCs) and plasma cells.
- Baricitinib (a JAK inhibitor) reduces type I IFN signaling and rescues phenotypes in PLD4-deficient models (mice and patient-derived cells).

QC result: Pass.

198: Mechanical Confinement and the Shape-Shifting Life of Melanoma Cells

Gustavo Barra — Fri, 14 Nov 2025 11:57:00 +0000

Mechanical Confinement and the Shape-Shifting Life of Melanoma Cells

Music:
Enjoy the music based on this article at the end of the episode.

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/mechanical-confinement-and-the-shape-shifting-life-of-melanoma-cells

️ Episode:
198: Mechanical Confinement and the Shape-Shifting Life of Melanoma Cells

️ Season:
1

Article title:
Mechanical confinement governs phenotypic plasticity in melanoma

Journal:
Nature

DOI:
10.1038/s41586-025-09445-6

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-11-14.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited core scientific claims and themes described in the transcript: confinement-driven phenotype switching (go-or-grow), HMGB2-mediated chromatin remodeling, cytoskeletal (acetylated tubulin cage) remodeling, Nesprin2/LINC association, Notch/BRN2 axis in invasion, and drug-tolerance implications.
- transcript topics: Confinement-driven phenotype switching (go-or-grow); Neuronal invasion gene program and MITF suppression; HMGB2 upregulation and chromatin remodeling; Perinuclear acetylated tubulin cage and ATAT1 involvement; Nesprin2 (SYNE2) and LINC complex in HMGB2 enrichment; Nuclear stiffening via Lamin A/C

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Confinement induces neuronal invasion program and MITF downregulation (SOX11, NEUROD1, NNAT, NEFM upregulation; MITF downregulation)
- HMGB2 upregulation is induced by confinement and HMGB2 concentration increases (approximately doubles) under confinement
- Confinement triggers assembly of a perinuclear acetylated tubulin cage; ATAT1 mediates tubulin acetylation
- Nesprin2 (SYNE2) is required for HMGB2 enrichment and for perinuclear cage assembly
- HMGB2 increases chromatin accessibility at neural crest/neuronal loci; AP-1 and SOX9 motifs enriched
- Notch signaling and BRN2 axis mediate HMGB2-driven invasion

QC result: Pass.

197: Somatic Mutation and Selection at Population Scale

Gustavo Barra — Thu, 13 Nov 2025 23:28:23 +0000

Somatic Mutation and Selection at Population Scale

Music:
Enjoy the music based on this article at the end of the episode.

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/somatic-mutation-and-selection-at-population-scale

️ Episode:
197: Somatic Mutation and Selection at Population Scale

️ Season:
1

Article title:
Somatic mutation and selection at population scale

Journal:
Nature

DOI:
10.1038/s41586-025-09584-w

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-11-13.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited spoken content for alignment with the article's main findings: NanoSeq methodology and ultra-low error sequencing; age-related somatic mutation accumulation in oral epithelium; driver landscape (NOTCH1, TP53, FAT1); in vivo saturation mutagenesis and hotspots (TP53 DNA-binding domain; RAC1); clonal growth dynam
- transcript topics: NanoSeq methodology and ultra-low error sequencing; Age-related somatic mutation accumulation in oral epithelium; Driver landscape and positive selection in oral epithelium; In vivo saturation mutagenesis and hotspot mapping (TP53 DNA-binding domain; RAC1 GTP-binding pocket); Clonal growth dynamics and tissue architectural plateau; Alcohol-related mutational signatures and ALDH2 genetics

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- NanoSeq achieves error rate below five errors per billion base pairs
- Age-related somatic mutation accumulation in oral epithelium ~18 SNVs per cell per year
- Driver landscape includes 46 genes under positive selection and >62,000 driver mutations in oral epithelium
- NOTCH1, TP53 and FAT1 are among strongest driver genes in oral epithelium
- Approximately 10–20% of cheek cells carry a driver mutation in older individuals
- In vivo saturation mutagenesis identifies hotspots in TP53 DNA-binding domain and RAC1 GTP-binding pocket

QC result: Pass.

196: Impact of Chromatin Accessibility QTLs Across Immune Contexts

Gustavo Barra — Wed, 12 Nov 2025 09:04:00 +0000

Impact of Chromatin Accessibility QTLs Across Immune Contexts

Music:
Enjoy the music based on this article at the end of the episode.

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/impact-of-chromatin-accessibility-qtls-across-immune-contexts

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-11-12.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited core caQTL biology and context: PBMC-wide caQTL mapping; dynamic caQTLs along cell trajectories; COVID-19 contexts and heritability enrichment; caQTL–eQTL–GWAS integration; ABC-based distal linking; CARD9 case in monocytes; emphasis on triple convergence for causal inference.
- transcript topics: Single-cell caQTL mapping in PBMCs across healthy, COVID-19, convalescent; caQTL–eQTL–GWAS integration and interpretability; Topic modeling and cell-state trajectories of caQTLs; Dynamic caQTLs during activation (k17 CD8 TEM); COVID-19 cellular context and heritability enrichment; Distal caQTLs and ABC-based enhancer–gene linking

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- caQTL count across PBMCs: 37,390
- dynamic caQTLs identified: 4,200
- caQTL sharing: less than 20% confined to a single context
- increase in GWAS-loci explainable when incorporating caQTLs (from ~32.9% to ~57.3%)
- COVID-19 cell-state k17 enriched for disease-relevant heritability (severe COVID-19)
- triple convergence (GWAS locus + caQTL + eQTL) in the same cellular context

QC result: Pass.

195: Tiny Shields: Lymphoid Microglia in Alzheimer’s Disease

Gustavo Barra — Tue, 11 Nov 2025 09:16:00 +0000

Music:
Enjoy the music based on this article at the end of the episode.

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/195-tiny-shields-lymphoid-microglia-in-alzheimers-disease

194: Bayesian History of Science: Watson and Crick and the Structure of DNA

Gustavo Barra — Mon, 10 Nov 2025 09:04:00 +0000

️ Episode 194: Bayesian History of Science: Watson and Crick and the Structure of DNA

In this episode of PaperCast Base by Base, we explore how Bayesian reasoning can be used to reconstruct the famous discovery of the DNA double helix by James Watson and Francis Crick, following the sequence of structural models proposed in the early 1950s and the evolving evidence that supported or undermined each hypothesis.

Study Highlights:
The author applies a naïve Bayes framework to four competing models of DNA proposed by Watson, Crick, and Linus Pauling, treating each model as a target theory evaluated against multiple lines of historical evidence such as X-ray diffraction patterns, base pairing rules, symmetry constraints, and stereochemical feasibility. Conditional probabilities for how well each model accounts for each piece of evidence are manually estimated from historical sources using a simple five-point scale ranging from strongly inconsistent to strongly consistent, and combined with prior probabilities to calculate posteriors and likelihood ratios. By updating priors model by model, the study reconstructs how initial triple-helix proposals were progressively disconfirmed, while intermediate double-helix attempts with incorrect base pairing achieved only modest support despite offering a plausible replication mechanism. A dramatic jump in posterior probability and in the likelihood ratio is observed for the final Watson–Crick model with complementary purine–pyrimidine base pairing, consistent bond geometry, compliance with Chargaff’s rules, and correct symmetry, which the author interprets as a form of “Bayesian surprise” that matches scientists’ retrospective sense of having made a genuine discovery. The analysis also shows how “soft” considerations, such as analogy to Pauling’s alpha helix and the promise of an explanatory replication mechanism, can be incorporated alongside hard experimental data within a Bayesian account of theory choice in the history of science.

Conclusion:
This work argues that Bayesian analysis provides a coherent way to track how evidence and prior expectations jointly shaped the path from early speculative DNA models to the accepted double-helix structure, offering a quantitative complement to narrative histories of scientific discovery.

Reference:
Small H. Bayesian history of science: The case of Watson and Crick and the structure of DNA. Quantitative Science Studies. 2023;4(1):209–228. https://doi.org/10.1162/qss_a_00233

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
If you'd like to support Base by Base, you can make a one-time or monthly donation here: https://basebybase.com/

193: SARM1, DNA, and the Death Signal

Gustavo Barra — Sun, 09 Nov 2025 16:40:00 +0000

️Episode 193: SARM1, DNA, and the Death Signal

In this episode of PaperCast Base by Base, we explore how the axon-degenerating enzyme SARM1 acts as a double-stranded DNA sensor that triggers NAD+ loss, cell death, and chemotherapy-induced neuropathy, opening up new possibilities for neuroprotective therapies.

Study Highlights:
The authors show that the immune adaptor SARM1 directly binds double-stranded DNA via its TIR domain and, once activated, rapidly degrades cellular NAD+ in a sequence-independent but length-dependent manner. Using a combination of biochemical assays and structural analyses, they demonstrate that SARM1 forms multimeric complexes with linear DNA, with optimal activation occurring when DNA fragments are long enough to engage multiple SARM1 molecules. In cells, cytosolic DNA introduced by transfection or released during chemotherapy colocalizes with SARM1, driving NAD+ depletion and promoting cell death, whereas mutations that disrupt DNA binding or complete knockout of SARM1 blunt this response. In mouse models, loss of SARM1 protects against chemotherapy-induced neuropathy, linking DNA sensing by SARM1 directly to treatment-related neurotoxicity and positioning this pathway as a therapeutic target.

Conclusion:
By revealing SARM1 as a double-stranded DNA sensor that couples cytosolic DNA to NAD+ degradation, cell death, and chemotherapy-induced neuropathy, this study highlights a druggable axis for preserving neural function during cancer treatment.

Reference:
Wang L, Liu Q, Li S, et al. SARM1 senses dsDNA to promote NAD+ degradation and cell death. Cell. 2025;188:1–18. https://doi.org/10.1016/j.cell.2025.09.026

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
If you'd like to support Base by Base, you can make a one-time or monthly donation here: https://basebybase.castos.com/

192: At Base-Pair Resolution: Chromatin’s Cis-Regulatory Conversations

Gustavo Barra — Sat, 08 Nov 2025 12:38:00 +0000

️Episode 192: At Base-Pair Resolution: Chromatin’s Cis-Regulatory Conversations

In this episode of PaperCast Base by Base, we explore how base-pair resolution maps of chromatin contacts reveal a unified, biophysical model of communication between enhancers, promoters, and other cis-regulatory elements in mammalian cells.

Study Highlights:
Using Micro Capture-C ultra (MCCu), the authors generate multidimensional chromosome conformation maps with single base-pair pixels, allowing them to resolve contacts between individual transcription factor motifs within cis-regulatory elements in mouse embryonic stem, hematopoietic progenitor, and erythroid cells. They show that nucleosome-depleted regions partition chromatin into nanoscale domains and form highly localized contacts with one another, while surrounding nucleosomes produce distinct patterns of linker spacing that mark inactive regions. By acutely degrading Mediator complex subunits with degron systems, they find that Mediator is critical for fine-scale promoter architecture and transcription complex stabilization but has only minor effects on large-scale enhancer–promoter contacts. Integrating MCCu data with coarse-grained molecular dynamics simulations and super-resolution imaging, they demonstrate that the physicochemical properties of chromatin itself can recapitulate observed contact patterns and help explain how transcription factor binding and nucleosome positioning coordinate cis-regulatory interactions.

Conclusion:
This work provides a high-resolution framework for linking chromatin biophysics to gene regulation, offering a roadmap for dissecting how specific protein complexes and nucleosome landscapes shape enhancer–promoter communication across the genome.

Reference:
Li H, Dalgleish JLT, Lister G, et al. Mapping chromatin structure at base-pair resolution unveils a unified model of cis-regulatory element interactions. Cell. 2025;188:1–19. https://doi.org/10.1016/j.cell.2025.10.013

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
If you'd like to support Base by Base, you can make a one-time or monthly donation here: https://basebybase.castos.com/

191: CATphishing: Synthetic Learning as an Alternative to Federated Learning in MRI

Gustavo Barra — Fri, 07 Nov 2025 09:36:00 +0000

️ Episode 191: CATphishing: Synthetic Learning as an Alternative to Federated Learning in MRI

In this episode of PaperCast Base by Base, we explore a Nature Communications study that proposes CATphishing—an approach that uses latent diffusion models to generate site-specific synthetic 3D brain MRIs for collaborative training without sharing raw data. The work spans seven institutions and 2,491 patients and evaluates whether models trained on synthetic data can match those trained via centralized data sharing or federated learning.

Study Highlights:
The authors train latent diffusion models locally at each site to capture dataset-specific MRI distributions and then aggregate only synthetic multi-contrast MRIs and tumor masks for downstream model training across centers. In IDH mutation status classification, models trained solely on synthetic data achieved performance comparable to centralized and federated approaches, with overall accuracy around 95.5% and AUC near 0.966, versus 96.2% and 0.979 for centralized training. A two‑stage tumor‑type pipeline—separating glioblastoma from IDH‑mutated tumors and then classifying oligodendroglioma versus astrocytoma—likewise showed similar end‑to‑end accuracy for synthetic versus real‑data strategies, landing near 90–92% overall. Fidelity and privacy were examined with FID and no‑reference image‑quality metrics and by a membership‑inference analysis that performed at chance, supporting the case for synthetic data as a viable, privacy‑preserving alternative in multi‑center AI development.

Conclusion:
CATphishing demonstrates that high‑fidelity synthetic MRI can enable cross‑institutional modeling with accuracy close to real‑data training while reducing privacy, communication, and coordination burdens in multi‑center collaborations.

Reference:
Truong NCD, Yogananda CGB, Wagner BC, Holcomb JM, Reddy DD, Saadat N, Bowerman J, Hatanpaa KJ, Patel TR, Fei B, Lee MD, Jain R, Bruce RJ, Madhuranthakam AJ, Pinho MC, Maldjian JA. Categorical and phenotypic image synthetic learning as an alternative to federated learning. Nature Communications. 2025;16:9384. https://doi.org/10.1038/s41467-025-64385-z

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
If you'd like to support Base by Base, you can make a one-time or monthly donation here: https://basebybase.castos.com/

190: dGCNA and single-cell maps reveal cell-type mechanisms in T2D

Gustavo Barra — Thu, 06 Nov 2025 09:10:00 +0000

Martínez‑López JA et al et al., Nature Communications - This episode examines a Nature Communications study that introduces differential Gene Coordination Network Analysis (dGCNA) applied to deep Smart-seq2 single-cell RNA-seq of human pancreatic islets from 16 T2D and 16 non‑T2D donors. The method uncovers cell type‑specific networks altered in T2D, validates mechanistic roles for CEBPG and TMEM176A/B, and contrasts beta- and alpha-cell programs. Key terms: single-cell RNA-seq, type 2 diabetes, dGCNA, beta cells, TMEM176A/B.

Study Highlights:
The authors developed dGCNA to compare gene‑pair coordination between T2D and non‑T2D single cells and applied it to two merged Smart‑seq2 datasets. In beta cells dGCNA identified eleven networks (NDCGs) linked to processes such as mitochondria, glycolysis, UPR, cytoskeleton, insulin secretion and ribosomes, many reproducible across datasets. Functional validation showed CEBPG modulates the unfolded protein response and insulin transcription, while TMEM176A/B controls beta cell microfilament organization and influences insulin secretion and in vivo glucose responses. Alpha cells displayed four distinct NDCGs (secretory granules, glycolysis, mitochondria, ribosome), highlighting cell type‑specific T2D alterations.

Conclusion:
dGCNA leverages single‑cell variability to reveal reproducible, cell type‑specific regulatory network changes in T2D, pinpointing mechanistic genes and pathways that are not evident from standard differential expression alone.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Single-cell mRNA-regulation analysis reveals cell type-specific mechanisms of type 2 diabetes

First author:
Martínez‑López JA et al

Journal:
Nature Communications

DOI:
10.1038/s41467-025-65060-z

Reference:
Martínez‑López JA et al., Single-cell mRNA-regulation analysis reveals cell type-specific mechanisms of type 2 diabetes. Nature Communications (2025). doi:10.1038/s41467-025-65060-z

License:
Creative Commons Attribution 4.0 International License

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/dgcna-cell-type-specific-t2d

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-11-06.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Substantively audited sections include: dGCNA methodology and NDCG identification in beta and alpha cells; functional validation of CEBPG and TMEM176A/B; cross-dataset replication and DESeq2 comparison; depth requirements (~1M reads/cell); and translational implications for therapy targets.
- transcript topics: Differential Gene Coordination Network Analysis (dGCNA) in islet cells; Beta-cell networks (NDCGs): Ribosome, Insulin secretion, Lysosome, UPR, Glycolysis, Mitochondria, Microfilaments, Microtubuli, Proliferation; Alpha-cell networks (NDCGs): Secretory granules, Glycolysis, Mitochondria, Ribosome; CEBPG as regulator of UPR and insulin transcription; knockout/knockdown effects; TMEM176A/B regulation of microfilament organization and insulin secretion; Deep sequencing depth requirement for dGCNA (~1M reads/cell)

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- dGCNA identified 11 beta-cell NDCGs with specificity to beta-cell dysfunction in T2D
- Beta-cell NDCGs hyper-coordinated: Ribosome, Insulin secretion, Lysosome; decoordinated: UPR, Microfilaments, Glycolysis, Proliferation, Glucose response, Microtubuli, Mitochondria
- Alpha cells show four NDCGs: Secretory granules, Glycolysis, Mitochondria, Ribosome
- CEBPG is a regulator of the beta-cell UPR; Cebpg KO/KD reduces UPR mediators and increases insulin transcription; Cebpg KD increases protein aggregation
- TMEM176A/B regulate beta-cell microfilament organization; TMEM176A/B KO/KD increases actin density and alters exocytosis-related genes
- dGCNA outperforms DESeq2 in identifying T2D-associated gene changes and shows replication across two datasets

QC result: Pass.

189: DNA methylation patterns facilitate tracing the origin of neuroendocrine neoplasms

Gustavo Barra — Wed, 05 Nov 2025 09:06:36 +0000

️ Episode 189: DNA methylation patterns facilitate tracing the origin of neuroendocrine neoplasms

In this episode of PaperCast Base by Base, we explore how genome-wide DNA methylation profiling can pinpoint the organ of origin for neuroendocrine neoplasms (NEN), with a special focus on lesions detected in the liver and long-debated “primary hepatic NEN”.

Study Highlights:
Using two independent cohorts totaling 212 NEN tissues, the authors profiled methylation patterns and visualized them with dimensionality-reduction approaches, revealing distinct clusters for most organ sites. Hepatic NEN without a detectable extrahepatic primary did not form a unique liver-specific cluster and instead colocalized with extrahepatic subtypes, frequently showing foregut-like methylation signatures. A latent methylation component–based Random Forest classifier achieved high accuracy in predicting organ site from biopsy material and suggested that many presumed primary hepatic NEN are likely misclassified metastases of unknown primary. Copy-number analyses supported organ‑site–specific patterns and further differentiated grades and subtypes, including NET versus NEC.

Conclusion:
Methylome profiling offers a practical path to identify the primary site in neuroendocrine neoplasms—including liver-detected cases—supporting more precise diagnosis and treatment selection in real-world pathology workflows.

Reference:
Goeppert B, Charbel A, Toth R, et al. DNA methylation patterns facilitate tracing the origin of neuroendocrine neoplasms. Nature Communications. 2025;16:9477. https://doi.org/10.1038/s41467-025-65227-8

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
If you'd like to support Base by Base, you can make a one-time or monthly donation here: https://basebybase.castos.com/

188: Proteomics + Machine Learning for Lyme Neuroborreliosis Diagnosis

Gustavo Barra — Tue, 04 Nov 2025 08:52:00 +0000

️ Episode 188: Proteomics + Machine Learning for Lyme Neuroborreliosis Diagnosis

In this episode of PaperCast Base by Base, we explore how large‑scale mass‑spectrometry proteomics of cerebrospinal fluid and plasma, paired with supervised machine learning, can distinguish Lyme neuroborreliosis from viral meningitis and non‑LNB controls in adults.

Study Highlights:
The authors analyzed 308 CSF and 207 plasma samples across development and validation cohorts to define host‑response protein signatures and train diagnostic classifiers. CSF proteomics yielded strong discrimination of LNB against viral meningitis and against controls, with independent‑cohort AUCs around 0.92 and 0.90, respectively, and highlighted immunoglobulin chains, complement factors, innate immune proteins, and cytoskeletal markers as key features. A plasma‑based model distinguishing LNB from controls achieved an AUC of about 0.80 in validation and captured systemic innate immunity, complement activation, lipid transport, and coagulation signatures. Across matrices, overlapping proteins illuminated compartmentalized immunity, with many immunoglobulins increased in CSF but relatively lower in plasma for LNB, and SHAP analyses prioritized features linked to humoral and innate responses as well as cell damage and migration.

Conclusion:
Machine‑learning‑assisted proteomics shows promise for less‑invasive diagnosis and monitoring of Lyme neuroborreliosis and could reduce reliance on lumbar puncture if validated prospectively.

Reference:
Nielsen AB, Fjordside L, Drici L, Ottenheijm ME, Rasmussen C, Henningsson AJ, Harritshøj LH, Mann M, Mens H, Lebech A‑M, Wewer Albrechtsen NJ. The diagnostic potential of proteomics and machine learning in Lyme neuroborreliosis. Nature Communications. 2025;16:9322. https://doi.org/10.1038/s41467-025-64903-z

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
If you'd like to support Base by Base, you can make a one-time or monthly donation here: https://basebybase.castos.com/

187: Gapped scheduling: CRLX101 + olaparib Phase I trial

Gustavo Barra — Mon, 03 Nov 2025 11:41:00 +0000

Nature Communications (2025) 16:9457 et al., Nature Communications - Phase I dose-escalation trial combining CRLX101 (nanoparticle camptothecin) with olaparib using a 48-hour gapped schedule in 24 patients with advanced solid tumors to determine MTD and assess pharmacokinetics, pharmacodynamics, safety, and preliminary efficacy. Key terms: CRLX101, olaparib, PARP inhibitor, topoisomerase I, gapped scheduling.

Study Highlights:
This phase I study combined tumor-targeted CRLX101 with gapped olaparib dosing in 24 heavily pretreated patients to identify a tolerable regimen and probe PD effects. The MTD/RP2D was CRLX101 12 mg/m² every two weeks with olaparib 250 mg twice daily on days 3–13 and 17–26. Pharmacokinetics were consistent with single-agent profiles and γH2AX in hair follicles and PBMCs increased after olaparib, indicating augmented DNA damage. Among 19 evaluable patients there were two confirmed partial responses and six stable diseases with manageable myelosuppression.

Conclusion:
Tumor-targeted TOP1 delivery paired with a 48-hour gapped olaparib schedule established a recommended Phase 2 dose (CRLX101 12 mg/m² + olaparib 250 mg BID on specified days), produced additive DNA-damage pharmacodynamics, showed preliminary antitumor activity, and was tolerable with expected hematologic toxicity, supporting further evaluation.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Tumor-targeted top1 inhibitor delivery with optimized parp inhibition in advanced solid tumors: a phase i trial of gapped scheduling

First author:
Nature Communications (2025) 16:9457

Journal:
Nature Communications

DOI:
10.1038/s41467-025-64509-5

Reference:
Nature Communications (2025) 16:9457; https://doi.org/10.1038/s41467-025-64509-5

License:
CC BY 4.0 (Creative Commons Attribution 4.0 International License)

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/gapped-scheduling-crlx101-olaparib-phase1

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-11-03.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited sections cover: DDR rationale, TOP1 and PARP inhibitors, CRLX101 nanoparticle delivery, gapped 48-hour scheduling, phase I trial design and dosing, pharmacodynamics (γH2AX) in surrogate tissues, pharmacokinetics, safety/toxicity, clinical efficacy signals (PR/SD), and exploratory genomic analyses.
- transcript topics: DNA damage response and PARP/TOP1 inhibitor synergy; CRLX101 nanoparticle delivery and tumor targeting via EPR; Gapped scheduling strategy with a 48-hour interval; Phase I trial design, dosing levels, and RP2D; Pharmacokinetics of CRLX101 and olaparib with no major interaction; Pharmacodynamics: γH2AX as a biomarker in hair follicles and PBMCs

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- MTD for CRLX101 and olaparib (RP2D) reported as 12 mg/m2 q2w and 250 mg BID on days 3–13 and 17–26
- 31-dose escalation with RP2D determined at DL4R
- 19 evaluable patients; 2 partial responses; 6 stable disease; median OS 6.06 months; median PFS 2.34 months
- γH2AX pharmacodynamics detected in hair follicles and PBMCs, increasing with combination treatment
- PK data show CRLX101 and olaparib with no major drug–drug interaction; CRLX101 half-life ~47 hours
- Gap scheduling mitigates bone marrow toxicity while allowing higher olaparib dosing

QC result: Pass.

186: TNFα–TGFβ Axis Disrupts Nasal Epithelium in Post‑COVID Syndrome

Gustavo Barra — Sun, 02 Nov 2025 11:28:00 +0000

️ Episode 186: TNFα–TGFβ Axis Disrupts Nasal Epithelium in Post‑COVID Syndrome

In this episode of PaperCast Base by Base, we explore a single‑cell RNA‑seq study of nasal biopsies showing that persistent immune signaling—not residual virus—drives aberrant epithelial differentiation in people with post‑COVID syndrome. fileciteturn1file0

Study Highlights:
Researchers profiled >56,000 cells from nasal tissue of individuals with moderate or severe post‑COVID syndrome, revealing marked depletion of proximal ciliated cells alongside expansion of basal and immune cell populations. Cell–cell communication and pathway analyses identified heightened TNFα and TGFβ signaling, with MIF–CD74 interactions and downstream NF‑κB/EGFR activity linking immune cells to epithelial remodeling. The team validated causality in air‑liquid interface cultures, where exposure to TGFβ and TNFα—alone and especially in combination—reduced ciliated‑cell differentiation and promoted basal‑cell skewing and EMT‑like programs. Viral RNA was undetectable in biopsies and inflammatory markers typical of acute infection were not elevated, indicating pathology independent of ongoing viral load.

Conclusion:
Targeting the TNFα–TGFβ inflammatory axis may help restore normal epithelial differentiation and mitigate respiratory comorbidities in severe post‑COVID syndrome.

Reference:
Reddy KD, Maluje Y, Ott F, Saurabh R, Schaaf A, Bohnhorst A, et al. scRNA‑seq reveals persistent aberrant differentiation of nasal epithelium driven by TNFα and TGFβ in post‑COVID syndrome. Nature Communications. 2025;16:9494. https://doi.org/10.1038/s41467-025-64778-0

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
If you'd like to support Base by Base, you can make a one-time or monthly donation here: https://basebybase.castos.com/

185: Altered Milk Tryptophan in Women Living with HIV

Gustavo Barra — Sat, 01 Nov 2025 18:41:00 +0000

️ Episode 185: Altered Milk Tryptophan in Women Living with HIV

In this episode of PaperCast Base by Base, we explore a longitudinal metabolomics study of human milk that reveals how maternal HIV infection reshapes tryptophan metabolism across lactation, with potential implications for infant immunity, growth, and neurodevelopment.

Study Highlights:
The authors profiled the milk metabolome from hundreds of mothers over the first 18 months postpartum and found a robust, sustained decrease in milk tryptophan alongside higher kynurenine and an elevated kynurenine-to-tryptophan ratio in women living with HIV. Targeted quantification at four months confirmed lower tryptophan and higher kynurenine in milk, and paired plasma analyses mirrored these shifts, indicating systemic depletion rather than altered transfer into milk. An initially unknown metabolite was identified as 3’-deoxy-3’,4’-didehydro-cytidine (ddhC), the free base of an interferon‑inducible antiviral ribonucleotide, and cytosine and dimethylarginine were also elevated, consistent with interferon-driven inflammation. A validation cohort of treated women showed concordant directions of effect and a higher KT ratio, supporting generalizability of the signature beyond the primary cohort.

Conclusion:
Milk tryptophan depletion and interferon‑linked metabolic remodeling in mothers with HIV may contribute to adverse outcomes in HIV‑exposed, uninfected infants and point to testable interventions targeting the kynurenine pathway.

Reference:
Tobin NH, Li F, Zhu W, Ferbas KG, Sleasman JW, Raftery D, Kuhn L, Aldrovandi GM. Altered milk tryptophan and tryptophan metabolites in women living with HIV. Nature Communications. 2025;16:9437. https://doi.org/10.1038/s41467-025-64566-w

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
If you'd like to support Base by Base, you can make a one-time or monthly donation here: https://basebybase.castos.com/

184: High-Accuracy Multiethnic XGBoost for Skin Cancer Identification

Gustavo Barra — Fri, 31 Oct 2025 17:08:06 +0000

️ Episode 184: High-Accuracy Multiethnic XGBoost for Skin Cancer Identification

In this episode of PaperCast Base by Base, we explore a large-scale study that builds a risk factor–based XGBoost model using the All of Us cohort to accurately identify patients with skin cancer across diverse ancestries.

Study Highlights:
Analyzing more than 400,000 participants, the authors quantify independent associations between genetic ancestry, lifestyle, social determinants of health, prior cancer history, and use of PDE5A inhibitors with skin cancer risk. They compare traditional logistic regression against gradient-boosted trees and show that logistic models have low precision for case identification, motivating a non-linear approach. The resulting multiethnic XGBoost model achieves high accuracy for identifying patients with any skin cancer, with F1 scores of 0.903 in individuals of European ancestry and 0.810 in non-European groups. SHAP importance and interaction analyses reveal strong non-linear effects of age and genotype principal components, and suggest that genetic and socioeconomic factors contribute more heavily to predictions in younger individuals.

Conclusion:
A multiethnic, non-linear model that integrates genetics, lifestyle, social determinants, and medication exposures can substantially improve early identification of skin cancer patients across ancestries, offering a precision-medicine tool to help reduce outcome disparities.

Reference:
D’Antonio M, Gonzalez Rivera WG, Greenes RA, Gymrek M, Frazer KA. A highly accurate risk factor–based XGBoost multiethnic model for identifying patients with skin cancer. Nature Communications. 2025;16:9542. https://doi.org/10.1038/s41467-025-64556-y

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
If you'd like to support Base by Base, you can make a one-time or monthly donation here: https://basebybase.castos.com/

183: The Genetic Lottery Goes to School: Better Schools Compensate for Genetic Differences

Gustavo Barra — Thu, 30 Oct 2025 09:34:08 +0000

️ Episode 183: The Genetic Lottery Goes to School: Better Schools Compensate for Genetic Differences

In this episode of PaperCast Base by Base, we explore a large causal study from Norway asking whether school quality can offset genetic differences in students’ academic skills. Using parent–offspring genetic trios from the Norwegian Mother, Father, and Child Cohort (MoBa) and nationwide administrative data, the authors combine within-family polygenic indices for educational attainment with school value-added measures to test if better schools compensate for genetic disparities.

Study Highlights:
The researchers computed polygenic indices for educational attainment for children while controlling for parental indices to isolate random within-family genetic variation and paired these with causal value-added estimates of school quality derived from population registers. They found a negative gene–environment interaction for reading, indicating that higher-quality schools reduce the impact of polygenic differences on reading scores by about six percent per one standard deviation of school quality exposure in grade 8, with the effect driven by gains among students at the lower end of the polygenic index distribution. For numeracy, the interaction was null despite clear main effects of both genetics and school value-added, a pattern consistent with higher persistence of numeracy skills during this developmental period. Validation analyses supported exogeneity of the within-family genetic component and of the school value-added measures, and sensitivity checks suggested that the findings are not artifacts of test scaling or ceiling effects. fileciteturn0file0

Conclusion:
In a causally identified framework, better schools can partially compensate for genetic differences in reading but not numeracy during lower secondary school, implying that investments in school quality may narrow genetically correlated gaps in foundational literacy.

Reference:
Cheesman R, Borgen N, Sandsør AMJ, Hufe P. The genetic lottery goes to school: Better schools compensate for the effects of students’ genetic differences. Proceedings of the National Academy of Sciences. 2025;122(43):e2511715122. https://doi.org/10.1073/pnas.2511715122

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
If you'd like to support Base by Base, you can make a one-time or monthly donation here: https://basebybase.castos.com/

182: Genotypic, Functional, and Phenotypic Characterization in CTNNB1 Neurodevelopmental Syndrome

Gustavo Barra — Wed, 29 Oct 2025 09:10:58 +0000

️ Episode 182: Genotypic, Functional, and Phenotypic Characterization in CTNNB1 Neurodevelopmental Syndrome

In this episode of PaperCast Base by Base, we explore a large cross-sectional cohort study that integrates genetics, cellular functional assays, and deep phenotyping to map the landscape of CTNNB1 neurodevelopmental syndrome. The authors analyze variant types across 127 individuals from 20 countries, probe Wnt/β-catenin signaling consequences in vitro, and connect genotypes to clinical trajectories and everyday function.

Study Highlights:
The cohort revealed 88 distinct CTNNB1 variants with a strong enrichment for predicted loss-of-function changes, and functional luciferase assays confirmed reduced Wnt/β-catenin pathway activity for most variants. A subset of truncating variants showed dominant-negative behavior, while a rare missense change (G575R) behaved as a gain-of-function with increased protein stability and signaling. Systematic clinical assessments documented frequent motor impairment, hypotonia, dysmorphic features, visual issues such as strabismus, and developmental delays including later independent walking. Missense variants tended to associate with comparatively milder phenotypes, with earlier walking and better communication, social, and feeding skills than frameshift, nonsense, splice, or deletion variants.

Conclusion:
By combining genomic curation, mechanistic assays, and standardized clinical measures, this study refines the natural history of CTNNB1 syndrome and highlights therapeutic avenues that may upregulate CTNNB1 expression while cautioning about variant-specific effects.

Reference:
Zakelj N, Gosar D, Miroševič Š, Sanders SJ, Ljungdahl A, Kohani S, Huang S, Leong LI, An Y, Teo MJ, Moultrie F, Jerala R, Lainšek D, Forstnerič V, Sušjan P, Lisowski L, Perez-Iturralde A, Orazem Mrak J, Chan HYE, Osredkar D. Genotypic, functional, and phenotypic characterization in CTNNB1 neurodevelopmental syndrome. Human Genetics and Genomics Advances. 2025;6:100483. https://doi.org/10.1016/j.xhgg.2025.100483

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
If you'd like to support Base by Base, you can make a one-time or monthly donation here: https://basebybase.castos.com/

181: Creatine Transporter SLC6A8: Conservation and Variant Impact

Gustavo Barra — Tue, 28 Oct 2025 17:14:53 +0000

️ Episode 181: Creatine Transporter SLC6A8: Conservation and Variant Impact

In this episode of PaperCast Base by Base, we explore how the creatine transporter gene SLC6A8 (CRT1) is evolutionarily conserved across terrestrial mammals and how disease-associated variants alter creatine uptake in vitro, shedding light on genotype–phenotype relationships in creatine transporter deficiency. fileciteturn0file0

Study Highlights:
The authors compared CRT1 amino acid sequences among multiple species and found striking conservation, with human transmembrane domains 1–10 identical across the mammals analyzed and most interspecies differences confined to terminal or loop regions. They curated benign and pathogenic missense variants from public databases and mapped them onto CRT1, observing that missense changes in N‑ and C‑termini are more often tolerated, whereas variants within core transmembrane domains and specific loop regions are frequently pathogenic. Functional assays in transfected cells demonstrated that eight of nine tested patient variants—most located in transmembrane segments—caused severe reductions in creatine transport, while a peripheral extracellular loop variant produced a more modest decrease. Integrating intolerance profiling with phylogenetic and experimental data, the study highlights a hotspot between amino acids 305–415 and underscores strong structural constraints that shape CRT1 function.

Conclusion:
Together, these results provide a practical framework for interpreting SLC6A8 variants in the clinic and suggest that domain-aware assessments can better predict which alterations are likely to impair creatine transport and contribute to neurodevelopmental disease.

Reference:
Diep T, Lipshutz GS. Evaluation of SLC6A8 species conservation and the effect of pathogenic variants on creatine transport. Human Genetics and Genomics Advances. 2025;6:100489. https://doi.org/10.1016/j.xhgg.2025.100489

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
If you'd like to support Base by Base, you can make a one-time or monthly donation here: https://basebybase.castos.com/

180: Leveraging Global Genetics Resources for Equitable Polygenic Prediction

Gustavo Barra — Mon, 27 Oct 2025 08:53:52 +0000

️ Episode 180: Leveraging Global Genetics Resources for Equitable Polygenic Prediction

In this episode of PaperCast Base by Base, we explore how multi-ancestry genome-wide association study resources and modern polygenic score methodologies can improve prediction accuracy across African, East Asian, and European populations, with a focus on practical, computationally efficient strategies that work even when individual-level data are unavailable.

Study Highlights:
This article systematically benchmarks leading single-source and multi-source polygenic score methods across 10 complex traits using GWAS summary statistics from Ugandan Genome Resource, Biobank Japan, UK Biobank, and the Million Veteran Program. The authors show that combining ancestry-aligned and European GWAS improves prediction in non-European targets and that independently optimized multi-source approaches often outperform jointly optimized methods while being far more computationally efficient. They introduce a generalizable use of the LEOPARD framework to estimate optimal linear combinations of population-specific scores using only summary statistics, achieving performance comparable to individual-level tuning in many settings. All methods are implemented in the GenoPred pipeline, providing an accessible, reference-standardized workflow for equitable polygenic prediction across diverse populations.

Conclusion:
Multi-source, summary-statistics–friendly approaches implemented in GenoPred offer a practical path to more accurate and equitable polygenic prediction, particularly when leveraging diverse GWAS resources and efficient tuning frameworks like LEOPARD.

Reference:
Pain O. Leveraging global genetics resources to enhance polygenic prediction across ancestrally diverse populations. Human Genetics and Genomics Advances. 2025;6:100482. https://doi.org/10.1016/j.xhgg.2025.100482

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
If you'd like to support Base by Base, you can make a one-time or monthly donation here: https://basebybase.castos.com/

Chapters

(00:00:14) - Placing genetic science to better health
(00:02:34) - PGS: The science of genetics
(00:06:31) - The comparative methods of ancestry science
(00:07:43) - Sumstat Tune: The genomic precision benchmark
(00:10:06) - LDpred2: Multi-Source Analysis
(00:11:30) - EUR vs AFR GWAS: The Size Paradox
(00:13:03) - The Best Multi-Source PGS
(00:17:09) - The Fight for Equitable Genomic Prediction
(00:21:14) - Personalized medicine in the cloud

179: Mosaicism for Autosomal Trisomies: Maternal Age, UPD, and Reproductive History in 1,266 Cases

Gustavo Barra — Sun, 26 Oct 2025 08:00:00 +0000

️ Episode 179: Mosaicism for Autosomal Trisomies: Maternal Age, UPD, and Reproductive History in 1,266 Cases
In this episode of PaperCast Base by Base, we explore a comprehensive literature analysis of 1,266 reported cases of autosomal trisomy mosaicism, contrasting prenatal cohorts—true fetal mosaicism and confined placental mosaicism—with postnatal diagnoses to clarify how maternal age and reproductive history relate to outcomes and uniparental disomy.

Study Highlights:
The authors screened 596 publications and assembled 948 prenatal and 318 postnatal mosaicism cases to compare outcome patterns and demographics. They found that advanced maternal age was more common in pregnancies with normal outcomes than in those with abnormal outcomes (73% vs 56%), while pregnancies ending in fetal loss showed a 50% advanced maternal age rate. Mosaic carriers with concomitant uniparental disomy of chromosomes 7, 14, 15, or 16 had markedly higher advanced maternal age than those with biparental disomy overall (78% vs 48%), suggesting age-associated biases in trisomy rescue. Reporting of reproductive history was limited, but prior fetal loss was nearly twice as frequent among mothers in the postnatal cohort compared with the prenatal cohort (30% vs 16%), and prior chromosomal abnormalities in earlier pregnancies appeared substantially enriched relative to non-mosaic series.

Conclusion:
These findings challenge assumptions drawn from non-mosaic trisomies and indicate that maternal age and reproductive history shape both outcomes and the likelihood of uniparental disomy in autosomal trisomy mosaicism, motivating better standardized reporting and registry-based studies.

Reference:
Kovaleva, N. V.; Cotter, P. D. Mosaicism for Autosomal Trisomies: A Comprehensive Analysis of 1266 Published Cases Focusing on Maternal Age and Reproductive History. Genes 2024, 15, 778. https://doi.org/10.3390/genes15060778

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
If you'd like to support Base by Base, you can make a one-time or monthly donation here: https://basebybase.castos.com/

Chapters

(00:00:00) - Causes of Trisomy 21 in maternal age
(00:01:59) - The Case of Mosaicism in America
(00:02:38) - Common Trisomy 4, Non-Moist mosaic cases
(00:03:09) - Autosomal mosaicism: The science, methodology, and impact
(00:07:57) - The mosaic trisomies in babies
(00:08:52) - Maternal age and mosaicism
(00:12:26) - Mosaic Trisomy Recurrence Risk

178: TP53 Reduced Penetrance: Predictive Features and Clinical Implications

Gustavo Barra — Sat, 25 Oct 2025 20:05:13 +0000

️ Episode 178: TP53 Reduced Penetrance: Predictive Features and Clinical Implications

In this episode of PaperCast Base by Base, we explore how a large ClinVar-anchored analysis integrates functional assays, computational predictors, immunogenicity estimates, allele frequencies, and clinical presentation to identify TP53 variants with reduced penetrance relative to classic Li-Fraumeni syndrome.

Study Highlights:
The authors reviewed ClinVar to assemble a set of TP53 variants flagged by diagnostic labs as reduced penetrance and compared them with benign and standard pathogenic reference sets using four independent functional assays and multiple in silico tools. Reduced penetrance variants tended to show intermediate activity in functional assays—most prominently in the Kato yeast transactivation readout—and had deleterious predictions by BayesDel and AlphaMissense, but with lower scores than standard pathogenic variants. These variants occurred at higher population frequencies than standard pathogenic variants, and carriers presented with cancer at later ages and with attenuated enrichment for classic Li-Fraumeni core cancers, although early-onset breast cancer and pediatric sarcomas remained associated. A random forest model using functional scores, predictors, immune fitness, and allele frequency prioritized 106 additional TP53 variants of uncertain or conflicting significance as potential reduced penetrance candidates for future study.

Conclusion:
The work outlines measurable features that distinguish reduced penetrance TP53 variants from both benign and standard high-penetrance variants, supporting refined classification and personalized surveillance strategies for carriers.

Reference:
Fortuno, C., Richardson, M. E., Pesaran, T., McGoldrick, K., James, P. A., & Spurdle, A. B. (2025). Characteristics predicting reduced penetrance variants in the high-risk cancer predisposition gene TP53. *Human Genetics and Genomics Advances*, 6, 100484. https://doi.org/10.1016/j.xhgg.2025.100484

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
If you'd like to support Base by Base, you can make a one-time or monthly donation here: https://basebybase.castos.com/

Chapters

(00:00:00) - The challenge of classifying TP53 variants
(00:03:52) - The pathogenicity of TP53
(00:08:46) - The RP variants and their pathogenicity
(00:10:11) - RP variants and the cancer screening debate
(00:14:15) - Lessened penetrance TP53 variants

177: Biallelic MCM8/MCM9 Variants: From Hypogonadism to Cancer Predisposition

Gustavo Barra — Fri, 24 Oct 2025 20:00:00 +0000

️ Episode 177: Biallelic MCM8/MCM9 Variants: From Hypogonadism to Cancer Predisposition

In this episode of PaperCast Base by Base, we explore a multi‑cohort clinical–genomic study that delineates the phenotype of individuals with biallelic germline variants in MCM8 or MCM9, clarifying links to polyposis and early‑onset cancers in addition to the long‑recognized association with hypogonadism.

Study Highlights:
Using population datasets (100,000 Genomes Project, UK Biobank, and gnomAD), a curated case series, and tumor sequencing, the authors assessed cancer and reproductive phenotypes among carriers of predicted deleterious variants. They found significant enrichment of biallelic MCM9 variants among participants with colonic and rectal polyps and with gastric cancer in the 100,000 Genomes Project, whereas no similar enrichment was seen for MCM8 or in UK Biobank. Across the aggregated case series (26 biallelic MCM8 and 28 biallelic MCM9 carriers), MCM9—but not MCM8—was associated with polyposis and early‑onset colorectal cancer, while both genes were linked to hypogonadism and to female germ cell tumors presenting in early adolescence. Tumor mutational‑signature analysis predominantly showed clock‑like processes without a consistent pattern of mismatch‑repair or homologous‑recombination deficiency, suggesting that many tumors in carriers are not defined by a distinctive repair‑defect signature. The authors recommend inclusion of MCM8/MCM9 on diagnostic panels for relevant clinical contexts and propose surveillance considerations for biallelic carriers.

Conclusion:
Biallelic MCM9 variants confer risk for polyposis, gastric cancer, and early‑onset colorectal cancer, and biallelic variants in either MCM8 or MCM9 are consistently linked to hypogonadism and early germ cell tumors, supporting panel inclusion and individualized surveillance strategies.

Reference:
Helderman, N. C., Yang, T., Palles, C., Terlouw, D., Mei, H., Vorderman, R. H. P., Cats, D., Díaz‑Gay, M., Jongmans, M. C. J., Ramdien, A., van de Beek, I., Eleveld, T. F., Green, A., Hes, F. J., van den Heuvel‑Eibrink, M. M., Van Der Kelen, A., Kliesch, S., Kuiper, R. P., Lakeman, I. M. M., Lashley, L. E. E. L. O., Looijenga, L. H. J., Oud, M. S., Steingröver, J., Tenenbaum‑Rakover, Y., Tops, C. M., Tüttelmann, F., de Voer, R. M., Westra, D., Wyrwoll, M. J., Golubicki, M., Antelo, M., Bonjoch, L., Terradas, M., Valle, L., Alexandrov, L. B., Morreau, H., van Wezel, T., Castellví‑Bel, S., Goldberg, Y., & Nielsen, M. (2025). Clinical syndromes linked to biallelic germline variants in MCM8 and MCM9. *Human Genetics and Genomics Advances*, 6, 100480. https://doi.org/10.1016/j.xhgg.2025.100480

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
If you'd like to support Base by Base, you can make a one-time or monthly donation here: https://basebybase.castos.com/

Chapters

(00:00:00) - Genetics of infertility and cancer
(00:06:32) - The genetic basis of cancer
(00:07:37) - MCM9 and cancer risk
(00:09:34) - MCM8 and MCM9 genetic cancer risk

176: FAHD1 and the Pyruvate-Driven Evolution of Hepatocellular Carcinoma

Gustavo Barra — Thu, 23 Oct 2025 19:48:00 +0000

️ Episode 176: FAHD1 and the Pyruvate-Driven Evolution of Hepatocellular Carcinoma

In this episode of PaperCast Base by Base, we explore how multi-omics integration—spanning single-cell transcriptomics, spatial mapping, and causal genetic inference—uncovers a pyruvate-hyperactive epithelial subpopulation in hepatocellular carcinoma and identifies FAHD1 as a central regulator linked to poor prognosis and immune evasion.

Study Highlights:
The authors harmonized six single-cell metabolic scoring methods across tens of thousands of tumor microenvironment cells and uncovered PyHighEpi cells with elevated pyruvate metabolism, stemness, and proliferation that concentrate in tumor cores. Spatial transcriptomics traced evolutionary trajectories from stromal transition zones into malignant foci and showed that pyruvate activity scales with spatial progression. Summary data-based Mendelian randomization pinpointed FAHD1 as a causal driver of HCC susceptibility, and FAHD1+ epithelial cells engaged cancer‑associated fibroblasts via ITGB2 to sculpt a TGF‑β/VEGF‑enriched niche consistent with immune escape. Functional knockdown experiments reduced proliferation, migration, and invasion, while an eight‑gene FAHD1‑derived risk score stratified survival and predicted responsiveness to PD‑1 blockade; in silico docking also suggested tivozanib as a potential FAHD1‑targeting compound.

Conclusion:
By linking mitochondrial pyruvate control to stromal crosstalk and immune suppression, the study positions FAHD1 as a therapeutic entry point and proposes risk-guided, metabolism‑plus‑immunity strategies for difficult‑to‑treat HCC.

Reference:
Huang, J., Liang, S., Sun, J., & Chen, H. (2025). FAHD1‑mediated pyruvate metabolism in hepatocellular carcinoma: Multi‑omics and causal genetic evidence. *Human Genetics and Genomics Advances*, 6, 100494. https://doi.org/10.1016/j.xhgg.2025.100494

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
If you'd like to support Base by Base, you can make a one-time or monthly donation here: https://basebybase.castos.com/

Chapters

(00:00:00) - Liver Cancer: The metabolic linchpin
(00:02:32) - The Pyruvate cancer causal link
(00:06:17) - The molecular switch in liver cancer
(00:11:43) - FHD1 and the cancer prognosis
(00:17:32) - Fahd1 and HCC

175: Predictive Prioritization of Pancreatic Enhancers Linked to Disease Risk

Gustavo Barra — Wed, 22 Oct 2025 14:51:00 +0000

️ Episode 175: Predictive Prioritization of Pancreatic Enhancers Linked to Disease Risk

In this episode of PaperCast Base by Base, we explore how enhancer–promoter 3D chromatin maps from five primary human pancreatic cell types were transformed into graph “tree” models to quantify enhancer connectivity and prioritize elements most critical for cell-type-specific gene expression, creating a framework to connect noncoding variants to function in pancreatic disease.

Study Highlights:
The authors profiled H3K27ac HiChIP and ATAC‑seq across 28 donors, building enhancer–promoter tree models that capture direct and indirect loops and reveal modular “forests” centered on promoter–promoter hubs.
They developed EPIC, a k‑nearest‑neighbors model using chromatin features and tree topology to rank enhancers by their predicted effect on cell‑type‑specific transcription and validated top predictions in primary human cells using CRISPRa/i with single‑cell RNA FISH readouts.
Direct E1 enhancer loops predominated and multiple enhancers additively boosted expression of lineage‑defining genes, while EPIC‑prioritized enhancers overlapped germline risk variants for type 2 diabetes and pancreatic ductal adenocarcinoma.
GWAS integration pointed to unexpected enrichment of PDAC‑associated variants in acinar enhancers and experimental perturbation at the XBP1 locus reduced transcripts in line with predicted effect sizes.

Conclusion:
Enhancer tree models coupled with the EPIC prioritization algorithm provide a scalable route to nominate and validate functional noncoding elements and their target genes in the human pancreas, sharpening variant‑to‑function studies and disease mechanism discovery.

Reference:
Wang L, Baek S, Prasad G, Wildenthal J, Guo K, Sturgill D, Truongvo T, Char E, Pegoraro G, McKinnon K, The Pancreatic Cancer Cohort Consortium, The Pancreatic Cancer Case‑Control Consortium, Hoskins JW, Amundadottir LT, Arda HE. Predictive prioritization of enhancers associated with pancreatic disease risk. Cell Genomics. 2026;6:101040. https://doi.org/10.1016/j.xgen.2025.101040

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
If you'd like to support Base by Base, you can make a one-time or monthly donation here: https://basebybase.castos.com/

Chapters

(00:00:14) - Pancreatic cancer risk map
(00:05:25) - How they mapped the enhancer network in the pancreas
(00:10:16) - Epic the enhancer network: diabetes, cancer
(00:13:32) - Pancreatic cancer: The genetic predisposition

174: TMEM217–SLC9C1: Wiring the cAMP Switch for Sperm Motility and Male Fertility

Gustavo Barra — Tue, 21 Oct 2025 18:13:00 +0000

️ Episode 174: TMEM217–SLC9C1: Wiring the cAMP Switch for Sperm Motility and Male Fertility

In this episode of PaperCast Base by Base, we explore a PNAS study revealing how TMEM217 forms a complex with the sperm-specific Na+/H+ exchanger SLC9C1 to organize cAMP signaling, sustain motility, and enable fertilization in mice.

Study Highlights:
Using phylogenetic profiling and interactomics, the authors identified TMEM217 as a conserved partner of the exchanger SLC9C1 and showed that both proteins localize to the principal piece of the sperm flagellum. Knockout of Tmem217 produced severe motility defects and infertility with hairpin flagellar bending, accompanied by loss of SLC9C1 and full-length soluble adenylyl cyclase, reduced cAMP levels, and dampened PKA and tyrosine phosphorylation. Co-immunoprecipitation and AlphaFold3 modeling demonstrated that TMEM217 binds the voltage-sensing domain of SLC9C1, supporting a mechanism that assembles the SLC9C1–sAC–cAMP axis during spermiogenesis. Pharmacologic boosting of cAMP paired with membrane-conditioning media restored motility and fertilization in vitro, yielding viable offspring after embryo transfer.

Conclusion:
Dissecting the TMEM217–SLC9C1 interface and local cAMP control suggests diagnostics and mutation-agnostic therapeutic strategies for asthenozoospermia and male infertility.

Reference:
Iida-Norita R, Miyata H, Ninomiya A, Emori C, Kamoshita M, Pan C, Wang H, Ikawa M. Formation of a complex between TMEM217 and the sodium-proton exchanger SLC9C1 is crucial for mouse sperm motility and male fertility. Proceedings of the National Academy of Sciences. 2025;122(42):e2513924122. https://doi.org/10.1073/pnas.2513924122

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
If you'd like to support Base by Base, you can make a one-time or monthly donation here: https://basebybase.castos.com/

Chapters

(00:00:00) - The mystery of athenosomes
(00:02:00) - How SLC9C1 regulates sperm motility
(00:06:43) - Knockout SLC9C1
(00:11:08) - TMP 217 restores sperm to full function
(00:12:35) - Immunity of TMM217 in mammalian sperm
(00:16:03) - Base by base science

173: Bottlebrush Block Copolymer Shields Muscles and Prevents DMD Onset

Gustavo Barra — Mon, 20 Oct 2025 09:04:00 +0000

️ Episode 173: Bottlebrush Block Copolymer Shields Muscles and Prevents DMD Onset

In this episode of PaperCast Base by Base, we explore a PNAS study showing how a synthetic bottlebrush block copolymer can act as a powerful membrane stabilizer to protect dystrophin-deficient muscle in Duchenne muscular dystrophy.

Study Highlights:
Researchers engineered and tested an amphiphilic bottlebrush diblock polymer, B–PEO43_10–PPO15_5, as a membrane stabilizer in the mdx mouse model of Duchenne muscular dystrophy. At nanomolar doses, the polymer rapidly restored twitch contractility in single dystrophin‑deficient fibers and showed ~150,000‑fold greater potency than optimized linear PEO–PPO copolymers. Early systemic dosing from postnatal day 1 to 21 prevented the surge of serum creatine kinase and blocked histologic hallmarks of damage in tibialis anterior and diaphragm while routine liver and kidney panels remained normal. In adult mice, pretreatment prevented IgG entry into myocardium during isoproterenol stress and significantly improved survival during combined handling and β‑adrenergic stress tests.

Conclusion:
This work positions bottlebrush block copolymers as fast‑acting, mutation‑agnostic membrane stabilizers with potential to preserve skeletal, respiratory, and cardiac muscle when deployed early and to complement gene‑based therapies.

Reference:
Cohen H, Bez Batti Angulski A, Quick JD, Kuebler TS, Thompson BR, Bauer J, Hahn D, Townsend D, Hassler JF, Hackel BJ, Lodge TP, Sham YY, Bates FS, Metzger JM. Synthetic bottlebrush block copolymer prevents disease onset in Duchenne muscular dystrophy. Proceedings of the National Academy of Sciences. 2025;122(42):e2513599122. https://doi.org/10.1073/pnas.2513599122

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
If you'd like to support Base by Base, you can make a one-time or monthly donation here: https://basebybase.castos.com/

Chapters

(00:00:00) - Duchenne Muscular Dystrophy: Chemical repair
(00:02:37) - Synthetic Polymers to stabilize muscle membranes in DC motor dys
(00:07:40) - Heart failure in MDX mice
(00:08:48) - Bottle Brush Polymer
(00:12:58) - Bottle Brush polymer
(00:18:14) - Deep Dive: Synthetic polymer fixes dystrophic muscle disease
(00:19:31) - Thinking beyond biological replacement to physical synthetic replacement

172: When Random DNA Fights Back: De Novo Gene Birth as Antiphage Defense

Gustavo Barra — Sun, 19 Oct 2025 15:59:00 +0000

️ Episode 172: When Random DNA Fights Back: De Novo Gene Birth as Antiphage Defense

In this episode of PaperCast Base by Base, we explore a PNAS study showing that short, previously nongenic DNA sequences can quickly evolve into genes that help bacteria survive phage attack, illuminating early steps of gene birth and the host–virus arms race. fileciteturn2file0

Study Highlights:
The authors screened two massive libraries totaling ~100 million (semi-)random open reading frames in Escherichia coli and recovered thousands of sequences that improved survival during T4 phage challenge. A set of short proteins, dubbed Random Inhibitors of Phage infection (Rips), broadly protected cells by activating the Rcs envelope-stress pathway and triggering colanic-acid capsule production that physically blocks adsorption. A second class of hits, Random T4 Inhibitor Products (rtp1–4), acted with specificity by reducing expression of the OmpC outer-membrane receptor, thereby limiting T4 and other OmpC-dependent phage entry; for some rtp genes the protective molecule was RNA rather than protein. Transcriptomics, reporter assays, and adsorption measurements supported these mechanisms while showing minimal growth penalties, and evolved T4 variants rapidly gained baseplate mutations that restored adsorption and infectivity.

Conclusion:
Random sequence space harbors many routes to immediate fitness gains, with de novo protein- and RNA-based functions rewiring bacterial envelopes and receptors in ways that both reveal mechanisms of gene birth and suggest new antiphage strategies.

Reference:
Frumkin I, Vassallo CN, Chen YH, Laub MT. Emergence of antiphage functions from random sequence libraries reveals mechanisms of gene birth. Proceedings of the National Academy of Sciences. 2025;122(42):e2513255122. https://doi.org/10.1073/pnas.2513255122 fileciteturn2file0

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
If you'd like to support Base by Base, you can make a one-time or monthly donation here: https://basebybase.castos.com/

Chapters

(00:00:14) - Deep Dive: The mystery of gene birth and evolution
(00:03:08) - De novo gene birth
(00:06:31) - Random but effective phage protection
(00:11:03) - Random sequences stop the T4 phage
(00:16:27) - The evolutionary process of the phage
(00:18:20) - Inventing new microbes: The origins of novelty

171: Virulence Hierarchies in the Tuberculosis Complex—What Makes Some Lineages Deadlier?

Gustavo Barra — Sat, 18 Oct 2025 08:50:00 +0000

Danchuk S et al., Proceedings of the National Academy of Sciences - Virulence Hierarchies in the Tuberculosis Complex—What Makes Some Lineages Deadlier?

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Virulence hierarchies within the
Mycobacterium tuberculosis
complex

First author:
Danchuk S

Journal:
Proceedings of the National Academy of Sciences

DOI:
10.1073/pnas.2507104122

Reference:
Danchuk S.N., Duffy S.C., Sullivan J., Beenish Rufai S., McIntosh F.A., Lupien A., et al.. Virulence hierarchies within the
Mycobacterium tuberculosis
complex. Proceedings of the National Academy of Sciences, 122. (2025). https://doi.org/10.1073/pnas.2507104122

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/virulence-hierarchies-in-the-tuberculosis-complexwhat-makes-some-lineages-deadlier

Chapters

(00:00:00) - Virulence hierarchies within the Mycobacterium Tu
(00:03:17) - Fighting mbovin in the calf
(00:06:05) - M. Bovis vs Amorgis TB pathogenesis
(00:09:58) - MTBC virulence and the big mystery
(00:11:52) - Immunity studies of human TB
(00:13:48) - Animal-adapted TB

170: Maternal Age, Meiotic Recombination Failure, and Triploidy in Humans

Gustavo Barra — Fri, 17 Oct 2025 09:25:43 +0000

Picchetta L et al., The American Journal of Human Genetics - Maternal Age, Meiotic Recombination Failure, and Triploidy in Humans

Music:
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Article title:
Maternal age and genome-wide failure of meiotic recombination are associated with triploid conceptions in humans

First author:
Picchetta L

Journal:
The American Journal of Human Genetics

DOI:
10.1016/j.ajhg.2025.09.014

Reference:
Picchetta L., Ottolini C.S., Tao X., Zhan Y., Jobanputra V., Vallejo C.M., et al.. Maternal age and genome-wide failure of meiotic recombination are associated with triploid conceptions in humans. The American Journal of Human Genetics, 112, 2665-2678. (2025). https://doi.org/10.1016/j.ajhg.2025.09.014

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/maternal-age-meiotic-recombination-failure-and-triploidy-in-humans

169: Deep mutational scanning of the insulin receptor guides precision therapy for insulin resistance

Gustavo Barra — Thu, 16 Oct 2025 20:13:00 +0000

Aslanzadeh V et al., Nature Communications - Deep mutational scanning of the insulin receptor guides precision therapy for insulin resistance

Music:
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Article title:
Deep mutational scanning of the human insulin receptor ectodomain to inform precision therapy for insulin resistance

First author:
Aslanzadeh V

Journal:
Nature Communications

DOI:
10.1038/s41467-025-64178-4

Reference:
Aslanzadeh V., Brierley G.V., Kumar R., Çubuk H., Vigouroux C., Matreyek K.A., et al.. Deep mutational scanning of the human insulin receptor ectodomain to inform precision therapy for insulin resistance. Nature Communications, 16. (2025). https://doi.org/10.1038/s41467-025-64178-4

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/deep-mutational-scanning-of-the-insulin-receptor-guides-precision-therapy-for-insulin-resistance

168: Low circulating miR-190a-5p predicts progression of chronic kidney disease

Gustavo Barra — Wed, 15 Oct 2025 08:10:00 +0000

Baird D et al., Nature Communications - Low circulating miR-190a-5p predicts progression of chronic kidney disease

Music:
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Article title:
Low circulating miR-190a-5p predicts progression of chronic kidney disease

First author:
Baird D

Journal:
Nature Communications

DOI:
10.1038/s41467-025-64168-6

Reference:
Baird D.P., Zang J., Connor K.L., Teenan O., Reck M., Cairns C., et al.. Low circulating miR-190a-5p predicts progression of chronic kidney disease. Nature Communications, 16. (2025). https://doi.org/10.1038/s41467-025-64168-6

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/low-circulating-mir-190a-5p-predicts-progression-of-chronic-kidney-disease

167: DeepScence: Detecting Senescent Cells at Single-Cell and Spatial Resolution

Gustavo Barra — Tue, 14 Oct 2025 19:01:00 +0000

Qu Y et al., Cell Genomics - DeepScence: Detecting Senescent Cells at Single-Cell and Spatial Resolution

Music:
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Article title:
Single-cell and spatial detection of senescent cells using DeepScence

First author:
Qu Y

Journal:
Cell Genomics

DOI:
10.1016/j.xgen.2025.101035

Reference:
Qu Y., Ji B., Dong R., Gu L., Chan C., Xie J., et al.. Single-cell and spatial detection of senescent cells using DeepScence. Cell Genomics, 5, 101035. (2025). https://doi.org/10.1016/j.xgen.2025.101035

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/deepscence-detecting-senescent-cells-at-single-cell-and-spatial-resolution

166: Molecular Squeezing: How Coronin, Cofilin, and AIP1 Rapidly Disassemble Actin Filaments

Gustavo Barra — Mon, 13 Oct 2025 08:53:00 +0000

Oosterheert W et al., Cell - Molecular Squeezing: How Coronin, Cofilin, and AIP1 Rapidly Disassemble Actin Filaments

Music:
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Article title:
Choreography of rapid actin filament disassembly by coronin, cofilin, and AIP1

First author:
Oosterheert W

Journal:
Cell

DOI:
10.1016/j.cell.2025.09.016

Reference:
Oosterheert W., Boiero Sanders M., Hofnagel O., Bieling P., Raunser S.. Choreography of rapid actin filament disassembly by coronin, cofilin, and AIP1. Cell, 188, 6845-6860.e27. (2025). https://doi.org/10.1016/j.cell.2025.09.016

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/molecular-squeezing-how-coronin-cofilin-and-aip1-rapidly-disassemble-actin-filaments

165: Protist Genomics: Key to Understanding Eukaryotic Evolution

Gustavo Barra — Sun, 12 Oct 2025 08:44:00 +0000

Schoenle A et al., Trends in Genetics - Protist Genomics: Key to Understanding Eukaryotic Evolution

Music:
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Article title:
Protist genomics: key to understanding eukaryotic evolution

First author:
Schoenle A

Journal:
Trends in Genetics

DOI:
10.1016/j.tig.2025.05.004

Reference:
Schoenle A., Francis O., Archibald J.M., Burki F., de Vries J., Dumack K., et al.. Protist genomics: key to understanding eukaryotic evolution. Trends in Genetics, 41, 868-882. (2025). https://doi.org/10.1016/j.tig.2025.05.004

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/protist-genomics-key-to-understanding-eukaryotic-evolution

164: m6A in the coding sequence: linking deposition, translation, and decay

Gustavo Barra — Sat, 11 Oct 2025 10:16:27 +0000

Ćorović M et al., Trends in Genetics - m6A in the coding sequence: linking deposition, translation, and decay

Music:
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Article title:
m6A in the coding sequence: linking deposition, translation, and decay

First author:
Ćorović M

Journal:
Trends in Genetics

DOI:
10.1016/j.tig.2025.06.002

Reference:
Ćorović M., Hoch-Kraft P., Zhou Y., Hallstein S., König J., Zarnack K.. m6A in the coding sequence: linking deposition, translation, and decay. Trends in Genetics, 41, 963-973. (2025). https://doi.org/10.1016/j.tig.2025.06.002

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/m6a-in-the-coding-sequence-linking-deposition-translation-and-decay

163: Animal origins: looping back in time

Gustavo Barra — Fri, 10 Oct 2025 08:54:14 +0000

Matar O et al., Trends in Genetics - Animal origins: looping back in time

Music:
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Article title:
Animal origins: looping back in time

First author:
Matar O

Journal:
Trends in Genetics

DOI:
10.1016/j.tig.2025.06.013

Reference:
Matar O., Marlétaz F.. Animal origins: looping back in time. Trends in Genetics, 41, 849-850. (2025). https://doi.org/10.1016/j.tig.2025.06.013

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/animal-origins-looping-back-in-time

162: Spatial miRNomics: technologies, challenges, and opportunities

Gustavo Barra — Thu, 09 Oct 2025 08:51:00 +0000

Robles-Remacho A et al., Trends in Genetics - A concise review of emerging methods to map microRNA (miRNA) expression in tissues with spatial context, covering imaging and sequencing approaches, technical barriers, bioinformatics needs, and clinical implications. Key terms: spatial miRNomics, microRNA, spatial transcriptomics, in situ polyadenylation, Patho-DBiT.

Study Highlights:
Spatial miRNA profiling is an emerging field with established singleplex imaging methods and new sequencing-based strategies that use in situ polyadenylation to capture nonpolyadenylated RNAs. STRS and Patho-DBiT demonstrated the feasibility of detecting hundreds to thousands of miRNAs in tissue sections, including FFPE samples, while imaging-based multiplexing remains limited. Bioinformatic tools such as miTEA-HiRes enable inference of miRNA activity from spatial transcriptomics, but challenges persist in sample fixation, retention, sensitivity for low-abundance miRNAs, and rRNA interference.

Conclusion:
Spatial miRNomics is now technically feasible and has revealed tissue- and disease-specific miRNA patterns, but further advances in multiplexed imaging, single-cell resolution, standardized workflows, and tailored bioinformatics are required to make spatial miRNA profiling routine and clinically actionable.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Spatially resolved microRNA expression in tissues: technologies, challenges, and opportunities

First author:
Robles-Remacho A

Journal:
Trends in Genetics

DOI:
10.1016/j.tig.2025.06.005

Reference:
Robles-Remacho A., Zou Y., Grillo M., Nilsson M. Spatially resolved microRNA expression in tissues: technologies, challenges, and opportunities. Trends in Genetics. 2025. https://doi.org/10.1016/j.tig.2025.06.005

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/spatially-resolved-microrna-expression-in-tissues-technologies-challenges-and-opportunities

161: Decoding genomic landscapes of introgression

Gustavo Barra — Wed, 08 Oct 2025 08:24:41 +0000

Huang X et al., Trends in Genetics - A concise review of methodological advances for identifying introgressed loci across genomes. The article surveys summary statistics, probabilistic modeling, and supervised learning approaches, their applications beyond humans, and the main challenges for robust inference and software implementation. Key terms: introgression, genomic-landscapes, probabilistic-modeling, supervised-learning, summary-statistics.

Study Highlights:
The review organizes recent progress into three methodological categories: summary statistics, probabilistic models, and supervised learning, highlighting complementary strengths. It documents applications across diverse taxa, including examples of adaptive and ghost introgression. The authors note key challenges such as confounding by ILS and population structure, model misspecification, and analysis opacity. They call for accessible implementations, transparent workflows, and systematic benchmarking to improve reliability.

Conclusion:
Progress requires leveraging complementary methods, improving transparency and benchmarking, and developing robust, accessible tools that scale across taxa and complex evolutionary scenarios.

Music:
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Article title:
Genomic landscapes of introgression

First author:
Huang X

Journal:
Trends in Genetics

DOI:
10.1016/j.tig.2025.07.001

Reference:
Huang X., Hackl J., Kuhlwilm M. Genomic landscapes of introgression. Trends in Genetics (2025). https://doi.org/10.1016/j.tig.2025.07.001

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/decoding-genomic-landscapes-of-introgression

160: Long reads meet single-cell omics

Gustavo Barra — Tue, 07 Oct 2025 08:55:53 +0000

Wen L et al., Trends in Genetics - This review surveys the integration of single-molecule long-read sequencing (SMS) with single-cell genomics, epigenomics and transcriptomics, describing platforms, methods and the new biological 'dark matter' now accessible at single-cell resolution. Key terms: single-cell sequencing, long-read sequencing, alternative splicing, structural variation, transposable elements.

Study Highlights:
SMS platforms (PacBio HiFi and Oxford Nanopore) have improved accuracy and enable direct full-length cDNA sequencing to resolve alternative splicing and isoforms in individual cells. Long reads substantially improve detection of repetitive elements, structural variants, ecDNAs and enable chromosome-scale haplotype phasing from small cell numbers. SMS-based single-cell epigenome methods capture allele-specific DNA methylation, histone marks, TF binding and higher-order 3D chromatin interactions, including within repetitive regions. New single-cell long-read methods (for transcriptome, genome and multiple epigenomic layers) are expanding capabilities but remain constrained by capture efficiency, cost and amplification artifacts.

Conclusion:
SMS-based long-read single-cell omics opens access to genomic and epigenomic 'dark matter'—full-length isoforms, repeats, SVs and allele-specific regulation—and points toward future single-cell de novo assemblies, multi-omics and spatial long-read applications.

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Article title:
Single-cell omics sequencing technologies: the long-read generation

First author:
Wen L

Journal:
Trends in Genetics

DOI:
10.1016/j.tig.2025.07.012

Reference:
Wen L. and Tang F. Single-cell omics sequencing technologies: the long-read generation. Trends in Genetics. 2025. https://doi.org/10.1016/j.tig.2025.07.012

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/the-longread-leap-in-singlecell-omics

159: Short Reads, Big Biodiversity: The Untapped Potential of Genome Skimming

Gustavo Barra — Mon, 06 Oct 2025 08:42:21 +0000

Bleidorn C et al., Trends in Genetics - This episode examines a Trends in Genetics review arguing that short-read shotgun sequencing and genome skimming remain powerful, cost-effective tools for biodiversity research. The authors highlight applications from species identification and biomass estimation to phylogenomics and museum-based genomics, and discuss how short reads complement long-read initiatives to meet Global Biodiversity Framework goals. Key terms: short-read sequencing, genome skimming, biodiversity monitoring, museum genomics, phylogenomics.

Study Highlights:
Emerging short-read platforms are lowering costs and increasing throughput, making large-scale sequencing more accessible. Genome skimming recovers organellar genomes and phylogenetically informative nuclear markers from low-coverage data, and assembly-free methods expand phylogenetic analyses to degraded or low-coverage samples. Short-read data enable accurate estimation of genome size and repeat content from skimmed datasets, and museum collections offer a rich source to fill taxonomic and genomic gaps for biodiversity monitoring. Together, these approaches support scalable monitoring and reference database building aligned with the GBF.

Conclusion:
Short-read shotgun sequencing, especially genome skimming and assembly-free analyses, remains a practical and scalable approach to generate genomic resources across taxa, complement long-read reference genomes, and accelerate biodiversity monitoring, phylogenomics, and conservation efforts under the Global Biodiversity Framework.

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Article title:
The untapped potential of short-read sequencing in biodiversity research

First author:
Bleidorn C

Journal:
Trends in Genetics

DOI:
10.1016/j.tig.2025.09.001

Reference:
Bleidorn C, Sandberg F, Martin S, Vogler AP, Podsiadlowski L. The untapped potential of short-read sequencing in biodiversity research. Trends in Genetics. 2025. https://doi.org/10.1016/j.tig.2025.09.001

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/the-untapped-potential-of-shortread-sequencing-in-biodiversity-research

158: Interruptions in repeat expansion diseases and the SD-MMEJ hypothesis

Gustavo Barra — Sun, 05 Oct 2025 13:02:18 +0000

Aston AN et al., Trends in Genetics - This opinion article reviews how short sequence interruptions within expanded tandem repeats alter somatic instability and clinical outcomes across multiple repeat expansion diseases, and proposes synthesis-dependent microhomology-mediated end joining (SD-MMEJ) as a unifying mechanism to explain the gain, loss, and complexity of interruptions. Key terms: repeat expansion, interruptions, SD-MMEJ, DNA repair, Huntington's disease.

Study Highlights:
Interruptions within expanded tandem repeats modulate somatic expansion and clinical severity and are observed to be dynamic, recurrent, locus-specific, and enriched near repeat–flank boundaries. The authors synthesize literature and sequencing observations to show interruptions can arise or be lost within a single generation and can form highly complex alleles. They propose SD-MMEJ, a Polθ-dependent alternative end-joining pathway, as a mechanism that produces insertions, deletions and repeating patterns via priming, synthesis and microhomology annealing after double-strand breaks. The model makes testable predictions about the role of flanking sequence structure, the need for double-strand breaks, and implications for diagnostics and therapeutic manipulation of interruptions.

Conclusion:
SD-MMEJ is presented as a plausible, testable mechanism that can account for most documented interruption dynamics; validating this model could improve interpretation of long-read sequencing, illuminate links between repair pathways and repeat instability, and suggest routes for therapeutic intervention.

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Article title:
Interruptions impact clinical features of repeat expansion diseases, but how are they gained and lost?

First author:
Aston AN

Journal:
Trends in Genetics

DOI:
10.1016/j.tig.2025.07.005

Reference:
Aston AN, Dion V. Interruptions impact clinical features of repeat expansion diseases, but how are they gained and lost? Trends in Genetics (2025). https://doi.org/10.1016/j.tig.2025.07.005

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/interruptions-in-repeat-expansion-diseases-how-are-they-gained-and-lost

157: Synthetic Gametes and the Non-Identity Problem

Gustavo Barra — Sat, 04 Oct 2025 13:00:00 +0000

Villalba A et al., Trends in Genetics - A concise exploration of how synthetic DNA could enable engineered haploid gametes, why that possibility intensifies the philosophical non-identity problem, and what this means for reproductive autonomy, disease prevention, and concerns about eugenics in future reproduction. Key terms: synthetic gametes, non-identity problem, reproductive ethics, synDNA, eugenics concerns.

Study Highlights:
The paper argues that advances in synthetic DNA may make de novo construction of haploid gamete genomes feasible, enabling precise control over inherited variants. This capability raises the non-identity problem: creating synthetic gametes may change which individual comes into existence, complicating person-affecting harm assessments. Synthetic gametes could reduce transmission of serious heritable diseases without directly benefiting any specific future person, shifting ethical focus toward impersonal wellbeing and reproductive autonomy. The authors contrast manufacturing gametes with embryo editing and discuss worries about eugenics while emphasizing differences from historical coercive practices.

Conclusion:
Synthetic gamete technology could expand reproductive options and reduce heritable disease but requires renewed ethical frameworks centered on impersonal wellbeing, autonomy, and careful governance.

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Article title:
Synthetic gametes and the non-identity problem: the babies of tomorrow

First author:
Villalba A

Journal:
Trends in Genetics

DOI:
10.1016/j.tig.2025.08.004

Reference:
Villalba A. & Räsänen J. Synthetic gametes and the non-identity problem: the babies of tomorrow. Trends in Genetics (2025). https://doi.org/10.1016/j.tig.2025.08.004

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/synthetic-gametes-and-the-non-identity-problem-the-babies-of-tomorrow

156: ZFKLO[N, ZUF and TKZLO[N Systems

Gustavo Barra — Fri, 03 Oct 2025 12:53:00 +0000

Cheng Y et al., Cell - This episode summarizes a technical report focused on ZFKLO[N and its relationships with ZUF and TKZLO[N systems as presented in the provided PDF. The document documents repeated observations, registry annotations (IZO[WZ), and structural motifs (tz�o~km�t{z) across samples. We highlight core methods, recurring patterns, and implications for standardized reporting. Key terms: ZFKLO[N, ZUF, TKZLO[N, IZO[WZ, tz�o~km�t{z.

Study Highlights:
The paper characterizes ZFKLO[N in relation to ZUF and TKZLO[N across multiple observational entries and registry annotations. It documents recurring tz�o~km�t{z motifs and repeated ZFKLO[N ozklwo� / nt~om� observations linked to ZUF signatures. Methods include observational surveys, comparative structural notation and use of an IZO[WZ registry for standardized descriptors, supporting continued harmonized reporting.

Conclusion:
Findings emphasize interdependence between ZFKLO[N and ZUF/TKZLO[N elements and the value of standardized IZO[WZ reporting to improve comparability; follow-up datasets and clearer nomenclature will aid interpretation.

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Article title:
ZFKLO[N ozklwo� roz{yo/Ðtno �|k�tkw �~kz�m~t|�{ytm

First author:
Cheng Y

Journal:
Cell

DOI:
10.1016/j.cell.2025.09.006

Reference:
Cheng Y., Dang S., Zhang Y., Chen Y., Yu R., Liu M., et al.. Sequencing-free whole-genome spatial transcriptomics at single-molecule resolution. Cell, 188, 6953-6970.e12. (2025). https://doi.org/10.1016/j.cell.2025.09.006

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/raefish-sequencing-free-whole-genome-spatial-transcriptomics-at-single-molecule-resolution

155: eIF3A/EIF3B haploinsufficiency and a syndromic cause of CHD

Gustavo Barra — Thu, 02 Oct 2025 08:36:25 +0000

Erkut E et al., The American Journal of Human Genetics - This episode examines an international cohort of 18 individuals with de novo or loss-of-function variants in EIF3A or EIF3B who present with congenital heart defects, craniofacial differences, and mild neurodevelopmental features, and reviews zebrafish CRISPR models that recapitulate key aspects of the human phenotype. Key terms: EIF3A, EIF3B, congenital heart disease, craniofacial dysmorphism, zebrafish model.

Study Highlights:
An international clinical series identified 18 individuals with de novo or predicted loss-of-function variants in EIF3A (n=4) or EIF3B (n=14) presenting mainly with congenital heart defects, craniofacial dysmorphisms, and mild neurodevelopmental features. Most variants are predicted to act via haploinsufficiency. CRISPR-Cas9 zebrafish mutants of orthologous eif3s10 and eif3ba showed hypoplastic heart tubes, absent craniofacial cartilage, microcephaly, coloboma, increased apoptosis, and embryonic lethality. The combined human and zebrafish data support EIF3A and EIF3B loss as the cause of a distinct autosomal-dominant neurocristopathy-like syndrome.

Conclusion:
Haploinsufficiency of EIF3A or EIF3B defines an autosomal-dominant syndrome with cardiac, craniofacial, and neurodevelopmental manifestations; both genes should be considered in genetic testing for congenital heart disease and related syndromes.

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Article title:
A cardiovascular, craniofacial, and neurodevelopmental disorder caused by loss-of-function variants in the eIF3 complex component genes EIF3A and EIF3B

First author:
Erkut E

Journal:
The American Journal of Human Genetics

DOI:
10.1016/j.ajhg.2025.09.008

Reference:
Erkut E, Somerville C, Schwartz MLB, et al. A cardiovascular, craniofacial, and neurodevelopmental disorder caused by loss-of-function variants in the eIF3 complex component genes EIF3A and EIF3B. Am J Hum Genet. 2025;112:1–18. doi:10.1016/j.ajhg.2025.09.008

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/eif3a-eif3b-loss-of-function-a-cardiocraniofacial-neurodevelopmental-syndrome

154: Multiple-testing corrections in IBD-based selection scans

Gustavo Barra — Wed, 01 Oct 2025 08:25:00 +0000

Temple SD et al., The American Journal of Human Genetics - Temple and Browning model correlations of identity-by-descent (IBD) rates to derive analytical and simulation-based genome-wide significance thresholds for selection scans, apply these to TOPMed and UK Biobank cohorts, and show many signals cluster near structural-variant hotspots. Key terms: identity-by-descent, selection scans, multiple testing, Ornstein-Uhlenbeck, population genetics.

Study Highlights:
The authors model standardized IBD rates along chromosomes as an Ornstein-Uhlenbeck process to obtain analytical and simulation-based multiple-testing thresholds that account for test spacing. In whole-genome simulations the methods approximately control the family-wise error rate, with the ≽5.3 cM scan tending toward anti-conservative behavior and the ≽6.3 cM scan conservative. Power exceeds 50% for hard sweeps with selection coefficients ≥0.01 at intermediate present-day allele frequencies. Applying the corrected thresholds to TOPMed and UKBB reduced the number of candidate loci and revealed shared excess-IBD regions enriched for structural variants.

Conclusion:
Modeling genomic autocorrelation of IBD rates yields practical multiple-testing corrections that reduce false positives in recent-selection scans, but interpretation must consider structural variation, demographic effects, and limitations of the OU approximation.

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Article title:
Multiple-testing corrections in selection scans using identity-by-descent segments

First author:
Temple SD

Journal:
The American Journal of Human Genetics

DOI:
10.1016/j.ajhg.2025.09.004

Reference:
Temple SD, Browning SR. Multiple-testing corrections in selection scans using identity-by-descent segments. Am J Hum Genet. 2025;112:1–21. doi:10.1016/j.ajhg.2025.09.004

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/multiple-testing-corrections-in-selection-scans-using-identity-by-descent-segments

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-10-01.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited sections describing the OU process modeling of IBD rates, the analytical Siegmund–Yakir approximation, the simulation-based thresholds, the power for hard sweeps, and the empirical findings including LCT, OCA2, HBB signals and the structural-variant mirages near XYLT1 and 22q11.21.
- transcript topics: Genome pattern recognition and IBD sharing; Identity-by-descent segments and selection scans; Multiple-testing corrections and FWER; Ornstein–Uhlenbeck process modeling of IBD rates; Analytical (Siegmund–Yakir) and simulation-based thresholds; Power to detect hard sweeps

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Model OU process to derive genome-wide significance for IBD-based scans
- Analytical Siegmund–Yakir approximation and simulation-based thresholds
- Power to detect hard sweeps with s >= 0.01 at intermediate allele frequencies
- LCT, OCA2, HBB signals observed across ancestries
- Cross-ancestry signals and structural-variant confounds near XYLT1 and 22q11.21
- Call for adopting OU-based thresholds and recognizing model limitations in founder/panmictic vs structured populations

QC result: Pass.

153: Skeletal muscle eQTLs map cardiometabolic genes

Gustavo Barra — Tue, 30 Sep 2025 09:24:00 +0000

Wilson EPW et al., The American Journal of Human Genetics - This episode covers a skeletal muscle eQTL meta-analysis of 1,002 individuals that discovered 18,818 conditionally distinct regulatory signals across 12,283 genes and integrated these with GWAS to nominate candidate genes for muscular and cardiometabolic traits, including functional validation of an INHBB regulatory variant. Key terms: eQTL, skeletal muscle, type 2 diabetes, GWAS colocalization, INHBB.

Study Highlights:
A meta-analysis of skeletal muscle eQTLs (n=1,002) identified 18,818 conditionally distinct signals for 12,283 genes. Colocalization with 26 GWAS traits produced 2,252 GWAS-eQTL colocalizations nominating 1,342 candidate genes, with 22% involving non-primary eQTLs and only 37% corresponding to the nearest protein-coding gene. Cross-tissue colocalization across muscle, adipose, liver, and islets linked 36% of tested T2D signals to 551 candidate genes and identified 95 genes uniquely detected in muscle. Functional reporter assays validated that rs11688682 increases enhancer activity and INHBB expression in myoblasts and adipocytes, consistent with eQTL directions.

Conclusion:
Leveraging a larger, conditionally-resolved skeletal muscle eQTL dataset improves gene prioritization for muscular and cardiometabolic GWAS signals and multi-tissue integration highlights shared and tissue-specific regulatory mechanisms; validated INHBB regulation illustrates a putative causal pathway meriting further functional follow-up.

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Article title:
Skeletal muscle eQTL meta-analysis implicates genes in the genetic architecture of muscular and cardiometabolic traits

First author:
Wilson EPW

Journal:
The American Journal of Human Genetics

DOI:
10.1016/j.ajhg.2025.09.003

Reference:
Wilson EPW, Broadaway KA, Parsons VA, et al. Skeletal muscle eQTL meta-analysis implicates genes in the genetic architecture of muscular and cardiometabolic traits. Am J Hum Genet. 2025;112:1–15. https://doi.org/10.1016/j.ajhg.2025.09.003

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/skeletal-muscle-eqtl-meta-analysis-implicates-genes-in-the-genetic-architecture-of-muscular-and-cardiometabolic-traits

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-09-30.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Substantively audited the transcript's claims related to: skeletal-muscle eQTL meta-analysis results, signal conditioning, GWAS-eQTL colocalizations, 3D/genomic-proximity implications, cross-tissue analyses across four tissues, and INHBB functional validation with luciferase assays; included limitations and broader imp
- transcript topics: Skeletal muscle eQTL meta-analysis results; Conditional signal identification and APEx methodology; GWAS-eQTL colocalization and candidate gene prioritization; Proximity vs 3D genome architecture in mapping; Cross-tissue colocalization across muscle, adipose, liver, and islets; Functional validation of INHBB rs11688682

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- 18,818 conditionally distinct eQTL signals identified across 12,283 genes in skeletal muscle
- 2,252 GWAS-eQTL colocalizations nominating 1,342 candidate genes
- Only 37% of colocalized GWAS signals mapped to the closest protein-coding gene; 44% were located more than 50 kb away
- INHBB locus: rs11688682 regulatory variant increases enhancer activity and INHBB expression; luciferase assays show ~2.5-fold in myoblasts and ~2-fold in adipocytes
- Cross-tissue colocalizations across skeletal muscle, adipose, liver, and pancreatic islets identified 551 candidate genes for 309 T2D signals; 9 genes hit all four tissues
- Meta-analysis increases detected eGenes and signals relative to GTEx or FUSION alone; 35% of eGenes harbor two or more signals; 20–32% more eGenes and 28–35% more signals than any

QC result: Pass.

152: Hereditary Alpha Tryptasemia: Single‑Well ddPCR Validation

Gustavo Barra — Mon, 29 Sep 2025 09:13:04 +0000

Alheraky A et al., Clinical Chemistry - This episode reviews a validation study of a single-well multiplex ddPCR assay that quantifies TPSAB1 α- and β-tryptase copy numbers to diagnose hereditary alpha tryptasemia (HαT) and defines an optimal basal serum tryptase (BST) cutoff for clinical screening. Key terms: hereditary alpha tryptasemia, ddPCR, TPSAB1, basal serum tryptase, copy number variation.

Study Highlights:
The authors developed a triplex single-well ddPCR assay to measure α- and β-tryptase CNVs and validated it in 281 symptomatic cases. The assay produced tight clustering with a 99% prediction-interval accuracy of 0.03 ± 0.27 copies, <0.01% cluster overlap, and 100% concordance with the reference double-well ddPCR on tested genotypes. In 141 patients without other causes of high BST, a linear gene–dose relationship was observed with an average BST increase of ~7.5 ng/mL per extra α copy and an optimal BST cutoff of 9.2 ng/mL (98.1% sensitivity, 96.6% specificity). The assay is suitable for routine diagnostics but cannot resolve certain cis-configuration genotypes and requires adequate DNA quality and input.

Conclusion:
The single-well multiplex ddPCR reliably determines HαT and, together with a BST screening threshold of 9.2 ng/mL in selected symptomatic patients, can be implemented as a routine diagnostic tool to aid differential diagnosis of mast cell–related disorders.

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Article title:
Hereditary Alpha Tryptasemia: Validation of a Single-Well Multiplex Digital Droplet PCR Assay in a Cohort of Symptomatic Patients

First author:
Alheraky A

Journal:
Clinical Chemistry

DOI:
10.1093/clinchem/hvad206

Reference:
Alheraky A, Wierenga ATJ, Simpelaar A, Hesp LB, Minovic I, Bagheri N, Roozendaal C, Span LFR, Oude Elberink HNG, Kema IP, Mulder AB. Hereditary Alpha Tryptasemia: Validation of a Single-Well Multiplex Digital Droplet PCR Assay in a Cohort of Symptomatic Patients. Clinical Chemistry. 2024;70(2):425–433. doi:10.1093/clinchem/hvad206

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/one-well-multiplex-ddpcr-for-hereditary-alpha-tryptasemia

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-09-29.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript sections describing (1) assay design (single-well multiplex ddPCR with BamHI digestion), (2) probe design and partitioning, (3) analytical performance (accuracy, BST correlation), (4) BST diagnostic thresholds (9.2 ng/mL, sensitivity/specificity), (5) gene-dose relationship (7.5 ng/mL per extra α
- transcript topics: Assay design: single-well multiplex ddPCR; Restriction digest strategy: BamHI to separate copies; Probe design and fluorescence readouts (HEX for α, FAM for β; AP3B1 reference; Droplet partitioning and absolute quantification; Gene-dose relationship with BST (7.5 ng/mL per extra α copy); BST diagnostic threshold: 9.2 ng/mL with high sensitivity/specificity

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- HαT is caused by extra α-tryptase copies in TPSAB1 and is autosomal dominant
- A single-well multiplex ddPCR assay quantifies α- and β-tryptase CNVs in TPSAB1 and TPSB2
- BamHI restriction digestion isolates individual copies to avoid undercounting due to cis-formatted copies
- BST is strongly correlated with α-copy number, with an average increase of 7.5 ng/mL per extra α copy
- BST cutoff of 9.2 ng/mL predicts HαT with 98.1% sensitivity and 96.6% specificity
- Assay accuracy is 0.03 ± 0.27 copy numbers with 99% prediction interval in 281 cases

QC result: Pass.

151: EQA of ctDNA Molecular Tumor Profiling in the COIN Consortium

Gustavo Barra — Sun, 28 Sep 2025 13:00:50 +0000

van der Leest P et al., Clinical Chemistry - An interlaboratory external quality assessment across 16 laboratories in the Dutch COIN consortium evaluated how diverse (pre)analytical workflows and analytical platforms affect detection and genotyping of ctDNA mutations in plasma. Key terms: ctDNA, liquid biopsy, external quality assessment, NGS, preanalytical standardization.

Study Highlights:
Six of 16 laboratories achieved a performance score >0.90 while others scored between 0.26 and 0.80, reflecting wide variability in results. Thirteen laboratories reached a 100% overall detection rate for analyzed variants, but actionable mutations such as EGFR p.(S752_I759del), EGFR p.(N771_H773dup), and KRAS p.(G12C) were frequently not accurately genotyped. A broad range of plasma input volumes, extraction kits, elution volumes, and analytical methods (ddPCR, small panels, and NGS) were used across sites. The study indicates that divergent (pre)analytical and analytical choices can lead to discrepant clinical outcomes.

Conclusion:
Standardization of (pre)analytical workflows and careful selection of analytical assays are needed to ensure reproducible and clinically reliable ctDNA-based molecular profiling.

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Article title:
External Quality Assessment on Molecular Tumor Profiling with Circulating Tumor DNA-Based Methodologies Routinely Used in Clinical Pathology within the COIN Consortium

First author:
van der Leest P

Journal:
Clinical Chemistry

DOI:
10.1093/clinchem/hvae014

Reference:
van der Leest P, Rozendal P, Hinrichs J, van Noesel CJM, Zwaenepoel K, Deiman B, Huijsmans CJJ, van Eijk R, Speel EJM, van Haastert RJ, Ligtenberg MJL, van Schaik RHN, Jansen MPH, Dubbink HJ, de Leng WW, Leers MPG, Tamminga M, van den Broek D, van Kempen LC, Schuuring E. External Quality Assessment on Molecular Tumor Profiling with Circulating Tumor DNA-Based Methodologies Routinely Used in Clinical Pathology within the COIN Consortium. Clinical Chemistry. 2024;70(5):759–767. doi:10.1093/clinchem/hvae014

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/eqa-of-ctdna-mutation-testing-across-the-coin-consortium

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-09-28.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript’s representation of the COIN EQA study’s design, numeric results, and implications for standardization in ctDNA testing, including specific mutation-genotype findings and methods.
- transcript topics: Interlaboratory variability in preanalytical workflows; DLA patient-derived plasma vs artificial reference samples; Loci analyzed: BRAF exon 15, EGFR exons 18–21, KRAS exons 2–3; Analytical methods: ddPCR, small-panel PCR, NGS; Genotyping accuracy vs detection rate and actionable mutations; Specific mutation misses: EGFR S752_I759del, EGFR N771_H773dup, KRAS G12C

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- 16 laboratories participated in the COIN EQA across plasma-derived ctDNA analysis
- Three artificial reference (spiked-in) plasma samples and three DLA (patient-derived) plasma samples were distributed
- Loci of interest: BRAF exon 15, EGFR exons 18–21, KRAS exons 2–3
- Eight different extraction methods and ten different analytical methodologies were used
- 13 of 16 laboratories (81%) achieved 100% overall detection rate for the analyzed variants
- Genotyping accuracy for actionable mutations was frequently lacking, with specific misses including EGFR S752_I759del (69%), EGFR N771_H773dup (50%), and KRAS G12C (33/64 calls, 52

QC result: Pass.

150: Patrilineal segmentary systems provide a peaceful explanation for the post‑Neolithic Y‑chromosome bottleneck

Gustavo Barra — Sat, 27 Sep 2025 12:58:00 +0000

Guyon L et al., Nature Communications - Forward-time simulations and coalescent inference show that variance in reproductive success among patrilineal descent groups combined with lineal fission can produce the observed post‑Neolithic decline in male effective population size (Y chromosome) without requiring large-scale intermale violence. Key terms: patrilineality, Y-chromosome bottleneck, population genetics, SLiM simulations, social structure.

Study Highlights:
The authors used SLiM forward-time socio-demographic simulations with tree-sequence recording, π-based diversity measures, and Bayesian skyline plots (BEAST) to compare bilateral and patrilineal scenarios with random or lineal fission, group growth variance, migration and modeled violence. They find that variance in reproductive success between patrilineal groups together with lineal fission is sufficient to drive a large reduction in male effective population size while female Ne continues to grow. Violence modeled as high male mortality produces a faster but smaller long-term effect than group-level reproductive variance, and polygyny alone is insufficient to reproduce the observed bottleneck. Timing analyses show that transitions in kinship systems linked to agro-pastoral shifts can produce bottlenecks compatible with archaeological dates.

Conclusion:
A shift toward segmentary patrilineal social organization — characterized by lineal fission and intergroup variance in reproductive success associated with the rise of agro‑pastoralism — can explain the post‑Neolithic Y‑chromosome bottleneck without invoking pervasive ancient violence.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Patrilineal segmentary systems provide a peaceful explanation for the post‑Neolithic Y‑chromosome bottleneck

First author:
Guyon L

Journal:
Nature Communications

DOI:
10.1038/s41467-024-47618-5

Reference:
Guyon L, Guez J, Toupance B, Heyer E, Chaix R. Patrilineal segmentary systems provide a peaceful explanation for the post‑Neolithic Y‑chromosome bottleneck. Nature Communications. 2024;15:3243. doi:10.1038/s41467-024-47618-5

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/patrilineal-segmentary-systems-and-the-postneolithic-ychromosome-bottleneck

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-09-27.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript sections that explain the Y-chromosome bottleneck, the peaceful patrilineal/segmentary hypothesis, model design (patrilocal residence, patrilineal descent, lineal vs random fission, variance in reproductive success), polygyny tests, simulation methods (SLiM), diversity measures (π-based) and BEAS
- transcript topics: Y-chromosome bottleneck timing and regional variation; patrilineal segmentary systems and peaceful explanation; lineal vs random descent/fission; patrilocal residence and female/male migration; variance in reproductive success and wealth transmission; polygyny tests and their impact on diversity

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Post-Neolithic Y-chromosome bottleneck occurred worldwide around 3,000–5,000 years ago; female Ne increased.
- Violence alone cannot explain the Y-chromosome bottleneck; a peaceful explanation is possible.
- Lineal (patrilineal) fission combined with variance in reproductive success reduces male Ne; lineal fission more effective than random fission.
- Polygyny alone reduces male Ne but is insufficient to account for the magnitude of the bottleneck (roughly 4x in a hyper-polygyny model).
- π-based and BEAST skyline plots provide complementary estimates; female-to-male Ne ratio can reach very high values (up to ~29.4 in some scenarios).
- Timing of the bottleneck is compatible with the rise of agro-pastoralism and shifts in kinship systems; explicit violence is not required.

QC result: Pass.

149: Tracing ancient Y chromosome variation

Gustavo Barra — Fri, 26 Sep 2025 09:41:30 +0000

Kivisild T et al., Hum Genet (2017) 136:529–546 - Review of how high-throughput sequencing of ancient human remains has enabled genome-scale study of male-specific Y chromosome variation, the methodological challenges of working with ancient Y data, and examples of regional continuity and turnover in Y haplogroups across Eurasia and the Americas. Key terms: ancient DNA, Y chromosome, haplogroups, population history, high-throughput sequencing.

Study Highlights:
High-throughput sequencing and capture methods now allow recovery of ancient Y chromosome sequences but face challenges from low endogenous DNA, post-mortem damage, repetitive Y regions and ascertainment bias of SNP-capture panels. Shotgun sequencing is preferred where human DNA content is high, while capture approaches increase overlapping SNP coverage but cannot discover novel variants. Ancient Y sequences from late Pleistocene and Holocene Eurasia map to major non-African founding lineages and reveal shifts in haplogroup composition through the Neolithic and Bronze Age, notably later expansions of R1a/R1b. Ancient American Y data confirm early presence of Q and C lineages and show distinct Palaeo-Eskimo Q sub-clades.

Conclusion:
Ancient Y chromosome data complement autosomal and mitochondrial evidence by revealing male-lineage continuity and turnover across time and space, but robust inference requires attention to damage, coverage, repeat regions and ascertainment bias and broader sampling from underrepresented regions.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
The study of human Y chromosome variation through ancient DNA

First author:
Kivisild T

Journal:
Hum Genet (2017) 136:529–546

DOI:
10.1007/s00439-017-1773-z

Reference:
Kivisild T. The study of human Y chromosome variation through ancient DNA. Hum Genet (2017) 136:529–546. DOI 10.1007/s00439-017-1773-z

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/cultural-hitchhiking-and-the-postneolithic-ychromosome-bottleneck

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-09-26.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript's coverage of ancient Y chromosome sequencing methods, damage authentication, and major demographic inferences (Europe, the Americas), plus Native American and Paleo-Eskimo lineages as described in the article.
- transcript topics: HTS challenges for ancient Y chromosome (repeats and X-Y homology); Shotgun sequencing vs capture-based enrichment; Damage authentication via end-of-read C to T patterns; Y-chromosome haplogroup history in ancient Europe (G, H, I, J, R1a/R1b, C); Bronze Age Yamnaya migrations and male-biased turnover; Native American Y-chromosome lineages Q and C and Malta Boy dual ancestry

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- DOI in metadata matches the canonical article DOI
- Article title in metadata matche...

Chapters

(00:00:14) - The genetic crash of the Neoles
(00:02:43) - The genetic bottleneck of the Neolithic
(00:09:08) - How patrilineal DNA helped explain human societies
(00:14:28) - Base by base science podcast

148: CHEK2 splice-site variants: minigene dissection

Gustavo Barra — Thu, 25 Sep 2025 08:36:14 +0000

Sanoguera-Miralles L et al., Clinical Chemistry - This episode examines a minigene-based functional study of 52 CHEK2 splice-site variants from the BRIDGES project, reporting widespread splice disruption, characterization of 89 transcripts, and an ACMG/AMP-informed tentative clinical classification. Key terms: CHEK2, splicing, minigene assay, variant classification, breast cancer.

Study Highlights:
The authors selected 52 candidate splice-site variants from 128 intron–exon boundary changes and tested them in three validated CHEK2 minigenes in MCF-7 cells. Forty-six variants (88.5%) impaired splicing and 34 produced negligible full-length transcript, generating a total of 89 different transcripts of which 59 are predicted to introduce premature termination codons. They identified complex outcomes including multi-exon skipping, cryptic site usage and a rare noncanonical TG acceptor activated by c.684-2A>G, and incorporated minigene read-outs into an ACMG/AMP-based point system to tentatively classify variants. The workflow allowed classification of 27 pathogenic/likely pathogenic and 5 likely benign variants, while 20 remained variants of uncertain significance.

Conclusion:
Minigene assays revealed high spliceogenicity among selected CHEK2 variants and, when combined with a modified ACMG/AMP framework, provided tentative clinical classifications but left a substantial fraction (38%) as VUSs, highlighting the need for complementary case-control, family, or patient RNA data.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Systematic Minigene-Based Splicing Analysis and Tentative Clinical Classification of 52 CHEK2 Splice-Site Variants

First author:
Sanoguera-Miralles L

Journal:
Clinical Chemistry

DOI:
10.1093/clinchem/hvad125

Reference:
Sanoguera-Miralles L, Valenzuela-Palomo A, Bueno-Martínez E, Esteban-Sánchez A, Lorca V, Llinares-Burguet I, García-Álvarez A, Pérez-Segura P, Infante M, Easton DF, Devilee P, Vreeswijk MPG, de la Hoya M, Velasco-Sampedro EA. Systematic Minigene-Based Splicing Analysis and Tentative Clinical Classification of 52 CHEK2 Splice-Site Variants. Clinical Chemistry. 2024;70(1):319–338. doi:10.1093/clinchem/hvad125

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/systematic-minigene-based-splicing-analysis-and-tentative-clinical-classification-of-52-chek2-splice-site-variants

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-09-25.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the spoken content for accuracy of core methods, results, and clinical implications of the CHEK2 minigene splicing analysis, including variant selection, three-minigene design, splicing outcomes, TG acceptor discovery, ACMG/AMP classification, and clinical impact; noted minor terminology variations.
- transcript topics: CHEK2 splicing and cancer risk; Minigene methodology and experimental design; Bioinformatic filtering and variant prioritization; Splicing outcomes and transcript diversity (89 transcripts, 59 with PTCs); ACMG/AMP-based tentative classification (32 variants; 27 P/LP, 5 LB; 20 VUS); Notable c.684-2A>G TG acceptor activation and exon 6 enhancers

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- 52 CHEK2 splice-site variants were analyzed in minigenes (from BRIDGES dataset).
- Three CHEK2 minigenes spanning all 15 exons were used for assays.
- 46 of 52 variants (88.5%) disrupted splicing; 34 produced negligible full-length transcript.
- 89 distinct transcripts were observed across variants; 59 predicted to introduce premature termination codons.
- 32 variants were tentatively classified by ACMG/AMP framework: 27 pathogenic/likely pathogenic, 5 likely benign; 20 remained VUS.
- Variant c.684-2A>G activated a noncanonical TG acceptor site, with exon 6 enhancers influencing recognition.

QC result: Pass.

147: Full-length ABO Haplotype Sequencing and Variant Resolution

Gustavo Barra — Wed, 24 Sep 2025 08:28:26 +0000

Ying Y et al., Clinical Chemistry 71:4 (2025) 510–519 - This episode reviews a Clinical Chemistry study that developed an improved one-step ultra-long-range PCR with PCR suppression primers and PacBio SMRT long-read sequencing to obtain 26.1 kb full-length ABO haplotypes from the 5′ UTR to the 3′ UTR, enabling comprehensive allele annotation and resolution of complex ABO variants. Key terms: ABO, haplotype sequencing, long-read sequencing, structural variants, 3' UTR.

Study Highlights:
The authors amplified a 26.1 kb full-length ABO amplicon using an improved one-step ultra-long-range PCR with PCR suppression primers and generated phased haplotypes by PacBio SMRT sequencing. They analyzed 158 haplotypes from 79 blood donors and 47 variant specimens, identifying coding, intronic, promoter, UTR, and structural variants. The work revealed allele-specific intron 1 (TA)n VNTR patterns, detailed 5′ and 3′ UTR motif/unit structures, and resolved large SVs including a 7337 bp deletion in an erythroid enhancer, recombinants, and chimeras. The method outperformed PCR-SBT and short-read NGS for phasing and SV detection but requires high-quality DNA and limited UTR/intronic validation by secondary methods.

Conclusion:
Full-length ABO haplotype sequencing spanning 5′ to 3′ UTR fills reference gaps, refines allele sequence patterns, and improves detection and resolution of structural and regulatory variants relevant to transfusion and transplantation; practical use is powerful but constrained by DNA quality and limited orthogonal validation for some noncoding variants.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Comprehensive Annotation of Complete ABO Alleles and Resolution of ABO Variants by an Improved Full-Length ABO Haplotype Sequencing

First author:
Ying Y

Journal:
Clinical Chemistry 71:4 (2025) 510–519

DOI:
10.1093/clinchem/hvaf015

Reference:
Ying Y, Zhang J, Hong X, Yuan W, Ma K, Huang X, Xu X, Zhu F. Comprehensive Annotation of Complete ABO Alleles and Resolution of ABO Variants by an Improved Full-Length ABO Haplotype Sequencing. Clinical Chemistry. 2025;71(4):510-519. doi:10.1093/clinchem/hvaf015

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/comprehensive-annotation-of-complete-abo-alleles-and-resolution-of-abo-variants

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-09-24.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript sections describing (1) end-to-end ABO haplotype sequencing from 5' UTR to 3' UTR, (2) ultra-long-range PCR with PCR suppression, (3) PacBio SMRT sequencing and haplotype phasing, (4) haplotype patterning and structural variations including deletions, recombination, and chimeras, and (5) clinical
- transcript topics: Full-length ABO haplotype sequencing (5' UTR to 3' UTR); Ultra-long-range PCR with PCR suppression; PacBio SMRT sequencing and CCS/pbmm2 analysis; Intron 1 TA VNTR and 5' UTR minisatellites; 3' UTR unit mapping (units 1–14) and NG_006669.2 comparison; Structural variations: deletions, recombination, chimeras

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- 26.1 kb full-length ABO haplotype amplicon with no splicing
- 158 haplotypes from 79 donors and 47 ABO variants
- Dominant alleles A1.01, A1.02, B.01, O.01.01, O.01.02; two rare alleles A2.05 and O.01.71
- TA VNTR in intron 1; median TA repeats: 21 for A1.02 and B.01; 13 for O alleles
- 5' UTR minisatellite motifs and 3' UTR units 1–14; NG_006669.2 lacks units 11–13
- 7337 bp deletion in an erythroid enhancer associated with Bel phenotype

QC result: Pass.

146: Automated, Decentralized cfDNA Profiling for Targetable and Resistance Alterations

Gustavo Barra — Tue, 23 Sep 2025 09:01:59 +0000

Chan HT et al et al., Clinical Chemistry - This study evaluates an automated, decentralized cfDNA NGS workflow (Oncomine Precision Assay GX with the Genexus system) in 298 patients with advanced solid tumors. The assay achieved 99% sequencing success, detected mut-ctDNA in about half of patients, identified actionable or resistance alterations in 18% of patients, and showed 72% concordance with matched tissue profiling. Detection sensitivity varied by cancer type, tumor burden, and metastatic site, and plasma-only variants were enriched after targeted therapy. Key terms: cell-free DNA, ctDNA, decentralized sequencing, Oncomine Precision Assay, liquid biopsy.

Study Highlights:
An automated point-of-care cfDNA NGS workflow yielded a 99% sequencing success rate and higher success than archived tissue. Approximately 50% of patients had detectable mut-ctDNA and 18% harbored targetable or resistance alterations, with overall tissue–plasma concordance of 72%. Plasma-only alterations (63 events) were found in 18% of patients and were more frequent after targeted therapy; detection sensitivity correlated with tumor fraction, lesion size, cancer type, and metastatic site. Clonal hematopoiesis and limited gene coverage of the assay were notable confounders.

Conclusion:
Automated, decentralized cfDNA genomic profiling is clinically feasible and can expand timely access to actionable genomic data, but results should be interpreted considering tumor burden, metastatic site, prior therapies, and clonal hematopoiesis.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Automated and Decentralized Genomic Profiling of Plasma Cell-Free DNA for Identification of Targetable and Resistance Alterations in Advanced Solid Tumors

First author:
Chan HT et al

Journal:
Clinical Chemistry

DOI:
10.1093/clinchem/hvaf045

Reference:
Chan HT et al. Automated and Decentralized Genomic Profiling of Plasma Cell-Free DNA for Identification of Targetable and Resistance Alterations in Advanced Solid Tumors. Clinical Chemistry 71:6 700–712 (2025). https://doi.org/10.1093/clinchem/hvaf045

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/automated-and-decentralized-genomic-profiling-of-plasma-cell-free-dna-in-solid-tumors

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-09-23.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited transcript sections describing the decentralized cfDNA workflow (OPA GX + Genexus), matched-normal CH filtering, plasma–tissue concordance, cancer-type shedding differences, plasma-only alterations, and complementary tissue testing.
- transcript topics: Foundations of cfDNA/ctDNA and liquid biopsy; Decentralized cfDNA sequencing workflow (OPA GX + Genexus); Clonal hematopoiesis and matched normal filtering; Plasma–tissue concordance and determinants (tumor burden and metastatic site); Plasma-only alterations and resistance evolution; Complementary role of tissue testing and limits of plasma CNV detection

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Study cohort of 298 patients with advanced solid tumors; comparison between automated decentralized cfDNA NGS (OPA GX + Genexus) and FoundationOne CDx tissue profiling
- cfDNA sequencing success: 99%; tissue sequencing success: 96%
- Mut-ctDNA detected in 49.5% after exclusion of clonal hematopoiesis (CH) and germline alterations
- 63 plasma-only alterations identified in 18% of patients
- Overall plasma–tissue concordance: 72%
- Concordance by metastatic site: liver metastases 84.2%, lung metastases 41.5%

QC result: Pass.

145: hs-MSI Validation: Detecting CMMRD and Pinpointing PMS2

Gustavo Barra — Mon, 22 Sep 2025 08:57:25 +0000

Marín F et al., Clinical Chemistry - This episode examines a validation study of a highly sensitive NGS-based microsatellite instability (hs-MSI) assay for diagnosing constitutional mismatch repair deficiency (CMMRD). The assay was tested on blinded blood cohorts and CMMRD-associated tumors, compared with a low-pass whole-genome LOGIC/MMRDness score, and evaluated for gene-specific MSI indel patterns that identify PMS2 biallelic carriers. Key terms: microsatellite instability, CMMRD, PMS2, hs-MSI assay, genetic diagnostics.

Study Highlights:
The hs-MSI assay was validated in blinded blood and tumor cohorts with very high accuracy for CMMRD detection (sensitivity ~98.5% and specificity 100%). Hs-MSI scores correlated strongly with LOGIC/MMRDness scores (r = 0.89 in blood, r = 0.82 in tumors). Analysis of indel allele distributions distinguished biallelic PMS2 pathogenic variant carriers with an accuracy of 0.997 and higher hs-MSI scores associated with younger age at first tumor diagnosis (r = −0.43).

Conclusion:
The hs-MSI assay is an accurate ancillary diagnostic tool for CMMRD that can detect MSI in blood and tumors and help pinpoint PMS2 as the affected germline gene.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
A Validated Highly Sensitive Microsatellite Instability Assay Accurately Identifies Individuals Harboring Biallelic Germline PMS2 Pathogenic Variants in Constitutional Mismatch Repair Deficiency

First author:
Marín F

Journal:
Clinical Chemistry

DOI:
10.1093/clinchem/hvae027

Reference:
Marín F, Canet-Hermida J, Bianchi V, et al. A Validated Highly Sensitive Microsatellite Instability Assay Accurately Identifies Individuals Harboring Biallelic Germline PMS2 Pathogenic Variants in Constitutional Mismatch Repair Deficiency. Clinical Chemistry. 2024;70(5):737–746. doi:10.1093/clinchem/hvae027

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/a-validated-highly-sensitive-microsatellite-instability-assay-identifies-pms2-variants-in-cmmrd

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-09-22.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited sections cover the hs-MSI assay development, 192-marker MSI panel, comparison with LOGIC/MMRDness, indel signatures distinguishing PMS2 carriers, performance metrics (sensitivity/specificity), cross-tissue detection (blood and tumor), and clinical implications for therapy and surveillance.
- transcript topics: Constitutional mismatch repair deficiency (CMMRD) overview; PMS2 gene, pseudogenes, and diagnostic challenges; highly sensitive MSI (hs-MSI) assay development; 192-microsatellite panel versus LOGIC/MMRDness; indel (insertion/deletion) signatures by affected gene; PMS2 signature as diagnostic marker (0.997 accuracy)

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- hs-MSI uses a panel of 192 microsatellites; threshold 4.57% used to call positive MSI status
- blood-based hs-MSI detected CMMRD with ~98.5% sensitivity and 100% specificity
- hs-MSI scores correlated with LOGIC/MMRDness scores (r = 0.89 in blood; r = 0.82 in tumors)
- PMS2 carriers show a distinctive indel signature with higher insertions; overall PMS2-indel accuracy 0.997
- hs-MSI detected MSI in all 24 tumor samples analyzed (across multiple organ origins)
- higher hs-MSI scores in blood correlated with younger age at first tumor (r = -0.43)

QC result: Pass.

144: Revising the age of the human chromosome 2 fusion

Gustavo Barra — Sun, 21 Sep 2025 11:19:09 +0000

Poszewiecka B et al., BMC Genomics (2022) 23:616 - This study presents an improved algorithm to compute the UBCS statistic and uses it to re-estimate the timing of the ancestral fusion that formed human chromosome 2, comparing human and Great Ape genomes. Key terms: human chromosome 2, chromosomal fusion, biased gene conversion, UBCS statistic, Great Apes evolution.

Study Highlights:
The authors developed an enhanced algorithm that uses inclusion–exclusion and dynamic programming to compute the Unexpected Bias Clustered Substitutions (UBCS) statistic exactly for complex intersecting clusters. Applying this method to human and Great Ape genomes, they estimate the HSA2 fusion occurred ~0.9 Mya with a 95% CI of 0.4–1.5 Mya. The UBCS proportion also tracked evolutionary distances across chimpanzee, bonobo, gorilla, orangutan and gibbon, supporting its use in speciation timing. Differences in some estimates (e.g., bonobo) were attributed to genome assembly quality and local mutational dynamics.

Conclusion:
An improved UBCS computation revises the HSA2 fusion estimate to about 0.9 Mya and demonstrates that biased clustered substitutions near telomeres can inform relative speciation timing among Great Apes.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Revised time estimation of the ancestral human chromosome 2 fusion

First author:
Poszewiecka B

Journal:
BMC Genomics (2022) 23:616

DOI:
10.1186/s12864-022-08828-7

Reference:
Poszewiecka B, Gogolewski K, Stankiewicz P, Gambin A. Revised time estimation of the ancestral human chromosome 2 fusion. BMC Genomics. 2022;23:616. doi:10.1186/s12864-022-08828-7

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/revised-time-estimation-of-the-ancestral-human-chromosome-2-fusion

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-09-21.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited portions covering the chromosome 2 fusion event, Biased Gene Conversion and UBCS, the improved inclusion–exclusion/dynamic programming method, the fusion date estimation, Great Ape divergence times, bonobo assembly caveats, and proposed future directions.
- transcript topics: Chromosome 2 fusion event and telomere signatures; Biased gene conversion and UBCS statistics; Algorithmic advance: inclusion–exclusion and dynamic programming; Fusion date estimation for HSA2 (~0.9 Mya) and CI; Great Ape speciation distances inferred from UBCS; Bonobo assembly quality and date discrepancy

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Enhanced algorithm for exact calculation of UBCS using inclusion–exclusion and dynamic programming
- HSA2 fusion date estimated at ~0.9 million years ago with 95% CI 0.4–1.5 Mya
- Bonobo-Homo fusion date estimated at ~0.67 Mya with CI 0–1.3 Mya and attribution to assembly gaps
- UBCS statistics used as a clock to infer evolutionary distances am...

Chapters

(00:00:14) - The moment that set Modern Humans apart from Great apes
(00:02:33) - The HSA2 fusion event reconstruction
(00:06:53) - The New Clock for Human Genome Dating
(00:10:41) - UBCS: A More Precise Human Evolution Clock?
(00:16:33) - Coming soon: Base by Base

143: Modelling genetic 'outliers' in ancient Eurasia (S1E143)

Gustavo Barra — Sat, 20 Sep 2025 09:44:21 +0000

Skourtanioti E et al., Cell - This episode summarizes a population‑genomic analysis that models genetic outliers in ancient Eurasian samples, using PCA and admixture modeling to test source combinations and estimate ancestry proportions among Caucasus, steppe, and Central Asian groups. Key terms: ancient DNA, admixture, Caucasus, Sarmatian, population genomics.

Study Highlights:
The authors analyze ancient human genomes with PCA and admixture modelling to identify and model genetic outliers across the Caucasus, steppe and Central Asia. They report fitted admixture proportions for competing source models (examples in the text include values such as 55±8%/45±8% and 84±4%/16±4%). Models highlight contributions linked to Sarmatian/Kazakhstan-related sources and Antiquity–Medieval Georgia/Alanic-related ancestry in some samples. The study uses a large panel of coded samples and explicit model comparisons to evaluate best‑fit ancestry sources.

Conclusion:
Admixture modelling and PCA reveal multi‑source ancestry for genetic outliers in ancient Eurasia, with detectable Sarmatian/Kazakhstan and Caucasus/Georgian‑related components in the tested samples.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
MODELLINGOFGENETIC'OUTLIERS'

First author:
Skourtanioti E

Journal:
Cell

DOI:
10.1016/j.cell.2025.07.013

Reference:
Skourtanioti E., Jia X., Tavartkiladze N., Bitadze L., Shengelia R., Tushabramishvili N., et al.. The genetic history of the Southern Caucasus from the Bronze Age to the Early Middle Ages: 5,000 years of genetic continuity despite high mobility. Cell, 188, 5278-5294.e21. (2025). https://doi.org/10.1016/j.cell.2025.07.013

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/the-genetic-history-of-the-southern-caucasus-5-000-years-of-continuity-despite-high-mobility

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-09-20.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited transcript segments describing IBD/ROH analyses, continuity and Bronze Age admixture, urban–rural contrasts, ACD findings, and study limitations.
- transcript topics: Southern Caucasus geography and population history; IBD (identical by descent) and ROH (runs of homozygosity) metrics; Long-term local genetic continuity vs Bronze Age admixture; Rural isolation vs urban genetic diversity; Artificial cranial deformation (ACD) findings in medieval remains; Limitations and caveats (undersampling, radiocarbon dating margins)

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 5
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- 230 ancient genomes from 50 sites spanning 3500 BCE to 700 CE
- IAD/ROH metrics used to infer relatedness and inbreeding
- Over 90% local genetic continuity across 5000 years
- Bronze Age influxes: northern steppe pastoralists and southern Anatolian populations
- Nedziki rural sites show 25-30% marriages between first/second cousins
- Semtavro urban cemetery shows high genetic diversity and distant outliers

QC result: Pass.

142: PALB2 ACMG/AMP Specifications

Gustavo Barra — Fri, 19 Sep 2025 08:05:00 +0000

Richardson M et al., The American Journal of Human Genetics - An international HBOP Variant Curation Expert Panel developed PALB2-specific specifications of the 2015 ACMG/AMP variant-interpretation guidelines by tailoring, limiting, or removing existing codes and tested them on 39 pilot variants to improve ClinVar concordance and harmonize classification. Key terms: PALB2, ACMG/AMP, variant curation, HBOP VCEP, ClinVar.

Study Highlights:
The HBOP VCEP reviewed ACMG/AMP codes and advised against 13 codes, limited six, and tailored nine to PALB2-specific biology. They set conservative population thresholds (BA1 0.1%, BS1 0.01%) and refined PVS1/PVS1(RNA) application, defining Tyr1183 as a C-terminal boundary for loss-of-function evidence. A pilot curation of 39 variants produced concordant classifications for 31 of 37 ClinVar variants (84%) and led to reclassification of several VUS/conflicting entries. The recommendations are conservative and evidence-based to support harmonized PALB2 variant interpretation and clinical reporting.

Conclusion:
PALB2-specific ACMG/AMP specifications provide a conservative, evidence-based framework that improves harmonization and accuracy of variant classification, supporting ClinVar deposition and clinical management of carriers.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Specifications of the ACMG/AMP variant curation guidelines for the analysis of germline PALB2 sequence variants

First author:
Richardson M

Journal:
The American Journal of Human Genetics

DOI:
10.1016/j.ajhg.2025.08.020

Reference:
Richardson M.E. et al., Specifications of the ACMG/AMP variant curation guidelines for the analysis of germline PALB2 sequence variants. The American Journal of Human Genetics. 2025;112:1–15. https://doi.org/10.1016/j.ajhg.2025.08.020

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/specifications-of-the-acmg-amp-guidelines-for-palb2-variant-interpretation

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-09-19.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript sections on PALB2 biology, HBOPVCEP PALB2 specifications, ACMG/AMP code modifications, pilot study outcomes, missense/pathogenicity limitations, PVS1/Tyr1183 boundary, splicing guidance, VUS backlog, and the need for high-throughput functional assays.
- transcript topics: PALB2 role in homologous recombination repair; HBOPVCEP PALB2 specifications and code changes; Pilot study results and ClinVar concordance; VUS resolution outcomes; Missense pathogenicity limitations and splicing considerations; PVS1, Tyr1183 boundary and RNA splicing guidance

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- HBOPVCEP PALB2 specifications exist and tailor/limit ACMG/AMP codes for PALB2
- Pilot with 39 PALB2 variants; 37 in ClinVar; 84% concordance with ClinVar classifications
- Among ClinVar VUS/conflicts (14), 4 variants resolved to benign or LP/Pathogenic
- Missense pathogenicity not established; restricted use of several missense-driven codes
- BA1 0.1% and BS1 0.01% population thresholds; PM2_Supporting used for rarity
- PVS1 and PVS1(RNA) weighting; Tyr1183 boundary; splicing predictions guide PVS1/RNA and BP7/BP7(RNA)

QC result: Pass.

141: RetiGene: a gene atlas for inherited retinal diseases

Gustavo Barra — Thu, 18 Sep 2025 08:57:00 +0000

Rivolta C et al., The American Journal of Human Genetics - RetiGene is an expert‑curated, openly accessible atlas integrating variant data, bulk and single‑cell RNA‑seq, and functional annotations for genes linked to inherited retinal diseases to aid diagnosis and research. Key terms: RetiGene, inherited retinal diseases, gene atlas, single-cell RNA-seq, diagnostic genetics.

Study Highlights:
The authors manually curated 470 genes (plus 4 loci) strongly associated with inherited retinal diseases and flagged 196 candidate genes and 17 discarded genes based on evidence strength. They integrated variant annotations, bulk (FANTOM5) and single‑cell RNA‑seq, and Gene Ontology‑based functional classifications to map genotype–phenotype relationships. Ciliary genes form the largest functional category and autosomal recessive inheritance predominates; expression patterns help explain syndromic versus non‑syndromic presentations. The resource is hosted at retigene.erdc.info and is intended for regular updates to support diagnostics, gene prioritization, and therapeutic development.

Conclusion:
RetiGene provides a continuously updated, expert‑curated gene atlas that integrates genetic and expression data to improve molecular diagnosis, panel design, and functional studies of inherited retinal diseases.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
RetiGene, a comprehensive gene atlas for inherited retinal diseases

First author:
Rivolta C

Journal:
The American Journal of Human Genetics

DOI:
10.1016/j.ajhg.2025.08.017

Reference:
Rivolta C., Celik E., Kamdar D., et al., RetiGene, a comprehensive gene atlas for inherited retinal diseases. The American Journal of Human Genetics (2025), https://doi.org/10.1016/j.ajhg.2025.08.017

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/retigene-a-comprehensive-gene-atlas-for-inherited-retinal-diseases

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-09-18.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Substantive auditing of the transcript sections describing the RetiGene atlas, gene counts (470 genes + 4 loci), functional categorization (with cilium as a leading category), inheritance patterns (68.9% AR), housekeeping paradox and tissue expression (retina-prevalent vs ubiquitous), RNA-seq and scRNA-seq findings, th
- transcript topics: Diagnostic challenges in inherited retinal diseases; RetiGene gene atlas and the 470 genes (plus 4 loci); Functional categorization of IRD genes (cilia, transmembrane transport, lipid metabolism); RNA-seq and single-cell RNA-seq expression patterns; Inheritance patterns and variant effects (LoF vs missense); Clinical impact: discarded genes (UNC119) and diagnostic panels

QC Summary:
- factual score: 8/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- 470 IRD-related genes (including 4 loci) retained as strongly disease-associated
- 196 candidate genes and 17 excluded genes
- Cilium was the largest functional category, comprising 83 of the 466 curated genes (17.8%)
- Autosomal recessive (AR) inheritance accounts for 68.9% of curated genes (across syndromic and non-syndromic)
- 47.6% of non-syndromic IRD genes were retina-prevalent; 40.1% of retina-restricted genes were ubiquitously expressed
- Single-cell data showed rod/cone/RPE specificity patterns and tissue-specific expression relevant to phenotypes

QC Flagged Items (audited and not fully supported):
- Numeric claim uncertain: 470 genes (including four loci) retained as strongly disease-associated (and 4 loci).
- Numeric claim uncertain: Cilium category comprises 83 genes (17.8%) among 466 curated genes.
- Numeric claim uncertain: 68.9% AR inheritance across curated genes.
- Numeric claim uncertain: 47.6% retina-prevalent among non-syndromic IRD genes.

QC result: Warning. Items above were flagged during automated QC; the editorial team reviewed them before release.

140: SOD1 Variant Landscapes: Activity and Abundance Maps

Gustavo Barra — Wed, 17 Sep 2025 09:15:00 +0000

Axakova A et al., The American Journal of Human Genetics - Axakova et al. produced comprehensive missense variant-effect maps for human SOD1 by assaying enzymatic activity in yeast and protein abundance in human HEK293T cells for ~86% of possible missense substitutions. The study links map patterns to sequence-structure-function features, uses kernel-density calibration to provide LLRp evidence for clinical interpretation, and shows the abundance map best discriminates pathogenic variants and supplies new evidence for many VUSs. Data and LLRp-calibrated scores are available on MaveDB and in supplemental DataS2. Key terms: SOD1, missense variants, VAMP-seq, variant-effect map, ALS.

Study Highlights:
The authors measured functional impacts for over 2,600 missense substitutions across SOD1 using multiplexed yeast complementation (total enzymatic activity) and VAMP-seq in HEK293T cells (protein abundance). Abundance and activity maps reveal complementary mechanisms: many deleterious variants reduce abundance (stability) while others impair activity through effects on metal binding, CCS interaction, or the electrostatic loop. The abundance map outperformed tested computational predictors, was calibrated to log-likelihood ratios (LLRp) for ACMG-style use, and provided new evidence for reclassifying 41% of ClinVar SOD1 VUSs. Map scores also correlated with ALS phenotypes such as age of onset and disease duration.

Conclusion:
Large-scale activity and abundance variant-effect maps for SOD1 provide mechanistic insights and calibrated functional evidence that can improve clinical interpretation of missense variants and prioritize individuals for SOD1-directed interventions.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Landscapes of missense variant impact for human superoxide dismutase 1

First author:
Axakova A

Journal:
The American Journal of Human Genetics

DOI:
10.1016/j.ajhg.2025.08.019

Reference:
Axakova A., Ding M., Cote A.G., et al. Landscapes of missense variant impact for human superoxide dismutase 1. The American Journal of Human Genetics. 2025;112:1–21. https://doi.org/10.1016/j.ajhg.2025.08.019

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/landscapes-of-missense-variant-impact-for-human-superoxide-dismutase-1

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-09-17.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript sections describing saturation mutagenesis of SOD1, yeast enzymatic activity assay, VAMP-seq abundance assay, the resulting variant-effect maps (activity and abundance), structural/MD insights (metal binding, Asn87, Gly128), genotype-phenotype associations, clinical implications, and limitations.
- transcript topics: SOD1 saturation mutagenesis and library generation; Yeast-based total enzymatic activity assay; VAMP-seq abundance assay in HEK293T cells; Variant-effect maps: activity versus abundance quadrants; Metal binding, CCS interactions, and electrostatic loop in SOD1; Second-shell residues (Asn87) and Gly128 dynamics via MD

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 5
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- 86% of all possible SOD1 missense variants were assayed in the variant-effect maps (activity and abundance).
- Over 2,000 SOD1 amino acid substitutions were generated via saturation mutagenesis.
- Variant-effect maps cover roughly 2,600 variants with substantial coverage (86% SNV-accessible substitutions detected).
- Two parallel assays were used: a yeast-based total enzymatic activity assay and a human-cell-based abundance assay (VAMP-seq).
- Abundance map outperforms activity map and several computational predictors in pathogenicity discrimination (e.g., AlphaMissense, CPT, ESM-1b, VARITY).
- Abundance scores show genotype–phenotype correlations with ALS features, including age of onset and disease duration; correlations with mouse protein half-life observed.

QC result: Pass.

139: MosCoverY: a coverage-based method to detect mosaic loss of Y

Gustavo Barra — Tue, 16 Sep 2025 09:03:00 +0000

Timonina V et al., The American Journal of Human Genetics - MosCoverY is a coverage-based method that estimates mosaic loss of the Y chromosome (mLOY) from exome or whole-genome sequencing by normalizing single-copy MSY exon coverage to matched autosomal exons. The method was validated in 212,062 UK Biobank men and applied to SHCS and TCGA datasets. Key terms: mosaic loss of Y, exome sequencing, whole-genome sequencing, coverage normalization, population genomics.

Study Highlights:
MosCoverY focuses on single-copy genes in the male-specific region of chrY and normalizes exon coverage to 100 autosomal exons matched by GC content and length, then rescales to the haploid expectation. Applied to 212,062 UK Biobank men, MosCoverY identified mLOY in 5.6% and produced cell-fraction estimates that strongly correlated with mLRRY, PAR-LOY, and WGS Control-FREEC. The method replicated known associations of mLOY with age, smoking, all-cause mortality, and germline loci, was robust to downsampling, and worked on tumor exomes from TCGA. MosCoverY can be used for single-sample analysis if the same capture kit is used, but capture-kit-specific recalibration is recommended.

Conclusion:
MosCoverY enables reliable detection and quantification of mLOY from exome and WGS coverage data at population scale, facilitating epidemiological, genetic, and tumor-based analyses.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
MosCoverY: A method to estimate mosaic loss of Y chromosome from sequencing coverage data

First author:
Timonina V

Journal:
The American Journal of Human Genetics

DOI:
10.1016/j.ajhg.2025.08.016

Reference:
Timonina V., Marchal A., Abel L., Cobat A., Fellay J. MosCoverY: A method to estimate mosaic loss of Y chromosome from sequencing coverage data. The American Journal of Human Genetics (2025) 112, 1–11. https://doi.org/10.1016/j.ajhg.2025.08.016

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/moscovery-a-new-method-to-estimate-mosaic-loss-of-y-chromosome-from-sequencing-coverage-data

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-09-16.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Substantively audited sections describing MosCoverY methodology (13 Y-exons and 100 autosomal exons, normalization, thresholding, and conversion to cell fraction), UK Biobank validation results, cross-method comparisons (mLRRY, PAR-LOY, Control-FREEC), TCGA tumor data, and SHCS/single-sample applicability along with li
- transcript topics: MosCoverY method overview; Y chromosome sequencing challenges in exome data; 13 Y exons and 100 autosomal exons normalization; Normalization to autosomal exons and scaling to 0.5; Binary mLOY threshold via IQR rule; Conversion to fraction of cells with mLOY

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- MosCoverY focuses on 13 Y-chromosome single-copy genes in X-degenerate regions and uses 100 autosomal exons matched by GC content and length for normalization.
- Normalized chrY coverage is scaled so the population median equals 0.5 (haploid Y baseline).
- Binary mLOY calls are defined by thresholding the scaled chrY coverage at Q1 - 1.5 × IQR.
- UK Biobank exome data: 212,062 male participants; MosCoverY identifies 11,897 (5.6%) mLOY carriers; mean cell fraction ~2.8%.
- Compared methods show mLRRY identifying ~5.4% and PAR-LOY ~10.1% mLOY carriers; MosCoverY exhibits higher concordance with WGS-derived Control-FREEC.
- TCGA data show higher mLOY prevalence in tumors (38%), with extremely high prevalence in papillary kidney adenocarcinoma (around 89%).

QC result: Pass.

138: Social exposome and dementia in Latin America

Gustavo Barra — Mon, 15 Sep 2025 09:09:00 +0000

Migeot J et al., Nature Communications - Large multicenter study linking a multidimensional social exposome (education, food insecurity, finances, healthcare access, childhood experiences) to cognition, function, neuropsychiatric symptoms, brain atrophy and connectivity in AD, FTLD and healthy aging across six Latin American countries. Key terms: social exposome, dementia, Latin America, brain connectivity, food insecurity.

Study Highlights:
The study evaluated 2,211 participants across six Latin American countries using a validated multidimensional social exposome (MSE) score spanning education, food insecurity, financial status, assets, healthcare access, childhood labor and traumatic events. Greater adverse MSE correlated with poorer cognition in healthy aging and with lower cognitive and functional performance and increased neuropsychiatric symptoms in Alzheimer’s disease (AD) and frontotemporal lobar degeneration (FTLD). Higher MSE adversity associated with reduced gray matter and altered resting-state functional connectivity in fronto-temporo-limbic and cerebellar regions. Food insecurity, financial resources, subjective socioeconomic status and access to healthcare emerged as key predictors and cumulative MSE outperformed individual factors.

Conclusion:
A cumulative, lifespan multidimensional social exposome strongly associates with worse clinical, cognitive and brain outcomes in aging and dementia across Latin America, highlighting the need for prevention and interventions that address social disparities.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Social exposome and brain health outcomes of dementia across Latin America

First author:
Migeot J

Journal:
Nature Communications

DOI:
10.1038/s41467-025-63277-6

Reference:
Migeot J, Pina-Escudero SD, Hernandez H, et al. Social exposome and brain health outcomes of dementia across Latin America. Nature Communications. 2025;16:8196. doi:10.1038/s41467-025-63277-6

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/social-exposome-and-brain-health-outcomes-of-dementia-across-latin-america

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-09-15.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript sections describing the MSE concept, lifespan-domain assessment, reverse-causation controls, neuroimaging findings (GMV and rs-fMRI connectivity), cross-site harmonization, and broader implications for dementia risk and social disparities.
- transcript topics: Multidimensional social exposome (MSE) concept; Lifespan-domain scoring and 10 domains; Reverse causation controls and SEM; Brain structural correlates: gray matter volume reductions in AD/FTLD; Functional connectivity and compensatory hyperconnectivity; Scanner harmonization and sensitivity analyses

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- MSE is a lifespan, multi-domain construct spanning 10 domains (education, food insecurity, financial status, assets, healthcare access, childhood labor, subjective SES, childhood e
- MSE is associated with worse cognition, reduced functional ability, and more neuropsychiatric symptoms across the sample; the global MSE is a stronger predictor than single factors
- In healthy aging, top MSE indicators include assets, education, and financial status; in dementia (AD, FTLD), predictors spread across domains with food insecurity, financial statu
- Adverse MSE is linked to reduced gray matter volume in dementia, with AD showing involvement of frontal lobes, insula, and cerebellum; FTLD shows fronto-temporo-cerebellar patterns
- Resting-state connectivity shows compensatory hyperconnectivity in AD with higher MSE, and patterns differ for FTLD; cross-network changes accompany structural decline.
- Analyses account for scanner differences via harmonization and covariates; sensitivity analyses show robustness to SNR and motion across sites.

QC result: Pass.

137: Rethinking RNA-binding proteins: riboregulation beyond the classics

Gustavo Barra — Sun, 14 Sep 2025 22:22:19 +0000

Hentze MW et al., Cell - A review that examines the expansion of the RNA-binding proteome, evaluates evidence for many non-canonical RBPs, and highlights riboregulation as an emerging mechanism by which RNA controls protein function, complexes, and metabolism. Key terms: RNA-binding proteins, non-canonical RBPs, riboregulation, intrinsically disordered regions, RNA interactome.

Study Highlights:
Large-scale UV crosslinking and proteomic approaches have dramatically expanded the catalogue of RNA-binding proteins to include many non-canonical, well-studied proteins that lack classical RNA-binding domains. Mapping efforts show that IDRs and nucleotide cofactor-binding folds frequently mediate these interactions, and validated examples reveal RNA can regulate protein-protein interactions, enzymatic activity, complex assembly, and transmembrane import. Representative cases include IRP1, GAPDH, ENO1, SHMT1, p62/vtRNA1-1, and lncRNA/circRNA regulators of metabolic enzymes and signaling complexes. The authors emphasize the need for orthogonal validation, high-resolution structures, and in vivo functional studies to distinguish biologically relevant riboregulation from methodological artifacts.

Conclusion:
Riboregulation extends RNA function beyond classical targets: many non-canonical RBPs engage RNA via IDRs or metabolic folds and RNA can directly modulate protein activity, interactions, and assemblies; rigorous validation and structural work are essential to define mechanism and relevance for physiology and disease.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Rethinking RNA-binding proteins: Riboregulation challenges prevailing views

First author:
Hentze MW

Journal:
Cell

DOI:
10.1016/j.cell.2025.06.021

Reference:
Hentze MW, Sommerkamp P, Ravi V, Gebauer F. Rethinking RNA-binding proteins: Riboregulation challenges prevailing views. Cell. 2025;188:4811-4827. https://doi.org/10.1016/j.cell.2025.06.021

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/rethinking-rna-binding-proteins-riboregulation-challenges-prevailing-views

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-09-14.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the narration's depiction of riboregulation concepts, non-canonical RBPs, validation methods (UV crosslinking, RIC/eRIC, OOPS/PTex, EU labeling, PLA, NMR), IDRs and Rossmann-fold binding surfaces, and functional examples (P62/vtRNA1-1, SHMT1, ENO1, metabolon formation with GlycoLINC, ATP5A1 import), plus virolo
- transcript topics: Riboregulation concept and paradigm shift; Non-canonical RNA-binding proteins (RBPs) and loss of classical RBDs; Validation technologies for RNA–protein interactions (UV crosslinking, RIC/eRIC, OOPS/PTex, EU labeling, PLA, NMR); IDRs as RNA-binding surfaces and Rossmann-fold cofactor pockets; Functional mechanisms: allostery, oligomerization, metabolon scaffolding; Specific riboregulation examples: P62/vtRNA1-1, SHMT1, ENO1, ATP5A1

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- DOI alignment between episode metadata and canonical article record
- Article title alignment between episode metadata and canonical article record
- Journal alignment between episode metadata and canonical article record
- License alignment between episode metadata and canonical article record
- Transcript claims about riboregulation concepts and specific mechanistic examples grounded in the article description

QC result: Pass.

136: Gene context drift and RECODR: predicting targets to prevent cancer relapse

Gustavo Barra — Sat, 13 Sep 2025 22:18:00 +0000

Jassim A et al., Cancer Cell - This episode summarizes Jassim et al.'s introduction of RECODR, a graph-embedding pipeline that measures gene co-expression context drift from sc/snRNA-seq to reveal drivers of tumorigenesis and treatment resistance and to nominate combination therapies validated in mouse models and predicted for human tumors. Key terms: RECODR, gene context drift, single-cell RNA-seq, treatment resistance, combination therapy.

Study Highlights:
The authors developed RECODR, which combines co-expression graph networks with Node2Vec/Word2Vec embeddings and alignment to quantify gene context drift between treatment states. In a mouse choroid plexus carcinoma (CPC) model RECODR prioritized ATM as a vulnerability and guided use of an ATM inhibitor; it also identified PARP1 as a target to mitigate monotherapy resistance. For combination AZD1390 and radiation resistance RECODR revealed an expanded immune-like program and nominated dasatinib, which in specific combination schedules produced marked survival benefit in mice. Applied to paired human medulloblastoma and TNBC samples, RECODR detected context-drift signatures and proposed subtype-specific therapies for testing.

Conclusion:
Measuring changes in gene co-expression context (gene context drift) with RECODR reveals resistance mechanisms invisible to expression-level analyses and can nominate context-specific targets and combination regimens for preclinical and clinical testing.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Gene context drift identifies drug targets to mitigate cancer treatment resistance

First author:
Jassim A

Journal:
Cancer Cell

DOI:
10.1016/j.ccell.2025.06.005

Reference:
Jassim A, Nimmervoll BV, Terranova S, et al. Gene context drift identifies drug targets to mitigate cancer treatment resistance. Cancer Cell. 2025;43:1608–1621. doi:10.1016/j.ccell.2025.06.005

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/gene-context-drift-identifies-drug-targets-to-mitigate-cancer-treatment-resistance

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-09-13.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited sections include: gene context drift concept; RECODR pipeline and four context-drift metrics; single-cell RNA-seq co-expression graphs; Node2Vec/Word2Vec embedding and Procrustes alignment; CPC mouse model with AZD1390 and radiation; PARP1 inhibitor AZD9574; dasatinib targeting of an immune-like network; transl
- transcript topics: Gene context drift concept; RECODR pipeline and context drift metrics; Single-cell RNA-seq and co-expression graphs; Node2Vec and Word2Vec embedding; Four context-drift metrics: neighbor number, graph reach, neighbor cosine, index gene cosine; CPC mouse model and DNA repair remodeling

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- DOI alignment between metadata and canonical article
- Article title alignment with canonical form
- Journal alignment with provided journal label
- License variant CC BY 4.0 alignment
- RECODR concept: context drift as resistance mechanism
- Single-cell RNA-seq data used to build co-expression graphs

QC result: Pass.

135: Micronutrients and Modern Human Evolution

Gustavo Barra — Fri, 12 Sep 2025 09:05:00 +0000

Rees J et al., The American Journal of Human Genetics - Rees et al. analyze signatures of positive selection in 276 genes linked to 13 dietary micronutrients across 40 global populations (HGDP). Using simulations and complementary selection scans, they report widespread local and oligogenic adaptation, with notable signals for zinc, iodine, and selenium. Key terms: micronutrients, positive selection, human evolution, local adaptation, zinc.

Study Highlights:
Using curated micronutrient-associated gene sets and whole-genome data from 913 individuals, the authors detect enriched signatures of positive selection across many populations. Power analyses with SLiM guided use of L_ST and Relate to identify both individual gene sweeps and oligogenic signals. SUMSTAT and CLUES2 timing analyses indicate some adaptations predate the Neolithic and align with migrations into novel soil environments. The results implicate micronutrient availability, driven by local geology and later cultural change, as a recurrent selective force in recent human evolution.

Conclusion:
Micronutrient-driven selection has likely shaped modern human genetic diversity more broadly than previously recognized; ongoing soil depletion and environmental change may increase risk of micronutrient-related disorders in populations lacking matching adaptations.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Global impact of micronutrients in modern human evolution

First author:
Rees J

Journal:
The American Journal of Human Genetics

DOI:
10.1016/j.ajhg.2025.08.005

Reference:
Rees J., Castellano S., Andrés A.M. Global impact of micronutrients in modern human evolution. The American Journal of Human Genetics. 2025;112:1–24. doi:10.1016/j.ajhg.2025.08.005

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/global-impact-of-micronutrients-in-modern-human-evolution

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-09-12.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited transcript sections describing the study's design, methods (FST, Relate, CLUES2, SUMSTAT), core findings across iodine, zinc, selenium, and magnesium, timing analyses, and implications for precision nutrition and evolutionary health.
- transcript topics: Soil geology as driver of micronutrient variation; Zinc transporter adaptations and out-of-Africa migrations; Iodine deficiency and thyroid gene adaptations (THRA, THRB, TRIP4, IYD); Selenium-related oligogenic adaptation (SGCD, AKAP6, PRKG1, KCNMA1); Magnesium toxicity adaptation and Neanderthal introgression (MECOM, FXYD2); Timing of selection with CLUES2 (iron/calcium pre-Neolithic, 28–42 ka)

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- 276 genes associated with 13 micronutrients analyzed; 269 MA genes after accessibility masking
- 40 populations; 913 HGDP individuals used in the analysis
- Methods included FST, Relate, CLUES2, SUMSTAT; haplotype networks (POPART) used for selected regions
- Key findings include iodine-associated adaptations in THRA/THRB/TRIP4/IYD and zinc transporter adaptations (SLC30A9, SLC39A11, SLC39A4) across non-African populations; selenium oli
- Transcript describes Neanderthal introgression contributing to magnesium-uptake adaptations via MECOM region
- Evolutionary timeline indicates adaptations long predate Neolithic farming for several nutrients

QC result: Pass.

134: Single-cell view of Barrett's esophagus and EAC

Gustavo Barra — Thu, 11 Sep 2025 09:01:57 +0000

Wenzel M et al., Cell Genomics - This episode reviews a single-cell transcriptional atlas comparing Barrett's esophagus, intestinal metaplasia, normal esophagus/gastric samples and esophageal adenocarcinoma. The study uses single-cell RNA profiling and UMAP clustering to resolve epithelial, stromal and immune cell populations, identify gastric-like and intestinal metaplasia cell states, and characterize tumor-associated CNV and transcriptional programs. We unpack the cell-type maps, marker gene patterns and implications for understanding progression from Barrett's lesions to EAC. Key terms: Barrett's esophagus, esophageal adenocarcinoma, intestinal metaplasia, single-cell RNA-seq, cell atlas.

Study Highlights:
The authors performed single-cell RNA‑seq with UMAP clustering across samples from Barrett's esophagus, intestinal metaplasia, gastric and esophageal adenocarcinoma specimens to define cell states. They identified discrete epithelial clusters (foveolar cells, chief cells, parietal cells, intestinal metaplasia cells, enteroendocrine cells) and multiple EAC tumor clusters, and reported CNV-level differences and transcriptional signatures distinguishing EAC from non-malignant tissues. The atlas documents gastric-like cell states within Barrett's lesions and changes in stromal and immune compartments associated with progression.

Conclusion:
Single-cell profiling maps cellular diversity across Barrett's esophagus, intestinal metaplasia and esophageal adenocarcinoma, producing an atlas to dissect tissue-specific and tumor-associated transcriptional programs.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Single-cell analysis of Barrett’s esophagus and carcinoma reveals cell types conferring risk via genetic predisposition

First author:
Wenzel M

Journal:
Cell Genomics

DOI:
10.1016/j.xgen.2025.100980

Reference:
Wenzel M.C., Dasmeh P., Plum P.S., Giel A., Hoppe S., Franitza M., et al.. Single-cell analysis of Barrett’s esophagus and carcinoma reveals cell types conferring risk via genetic predisposition. Cell Genomics, 5, 100980. (2025). https://doi.org/10.1016/j.xgen.2025.100980

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/single-cell-maps-link-intestinal-metaplasia-to-esophageal-adenocarcinoma-risk

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-09-11.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited core scientific themes: Barrett's esophagus and cancer risk, single-cell RNA sequencing atlas, LDSR integration with GWAS, intestinal metaplasia as a risk-rich cell type, distinct EAC tumor clusters, microenvironment contributions, and translational/clinical implications.
- transcript topics: Barrett's esophagus and esophageal adenocarcinoma risk; Single-cell RNA sequencing atlas across BE, intestinal metaplasia, normal esophagus, gastric tissue, and EAC; LDSR integration of GWAS risk variants with cell-type expression; Intestinal metaplasia cells as key risk-enriched population; Esophageal cancer tumor clusters (EAC-01 to EAC-04) with distinct programs; Tumor microenvironment and stromal/immune enrichment of risk

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Single-cell atlas generated across Barrett's esophagus, intestinal metaplasia, normal esophagus, and gastric tissues with esophageal adenocarcinoma (EAC) samples using single-cell
- GWAS-derived cancer risk variants overlaid with single-cell map via linkage disequilibrium score regression (LDSR) to identify cell-type enrichment
- Intestinal metaplasia cells show the strongest enrichment for esophageal cancer risk variants, despite relative genomic stability
- EAC contains multiple tumor clusters with divergent transcriptional programs (e.g., EAC-02 proliferative via WNT11 and CNV patterns; EAC-01 invasive via MMP/MMP7-related activity)
- Microenvironmental cell types (fibroblasts, memory CD4+ T cells, plasmacytoid dendritic cells) also show risk variant enrichment
- Barrett's esophagus risk is described as more systemic/mechanical (reflux mechanics, LES integrity) whereas cancer risk is driven by local cellular processes

QC result: Pass.

133: Long-read meta-pangenomics links gut genomes to child growth

Gustavo Barra — Wed, 10 Sep 2025 09:12:48 +0000

Minich JJ et al., Cell - Minich et al. apply PacBio and Oxford Nanopore long‑read metagenomics to generate 986 complete metagenome‑assembled genomes from Malawian toddler fecal samples, then use pangenome analyses, mGWAS and machine learning to link microbial genes, strains and genome stability to child linear growth and breastfeeding. Key terms: long-read metagenomics, cMAGs, pangenome, pediatric undernutrition, microbial GWAS.

Study Highlights:
Long‑read sequencing (PacBio, ONT) recovered far more complete genomes per Gbp than short reads, yielding 986 cMAGs (839 circular) across 47 samples and an expanded 210-sample set. Pangenome and microbial GWAS analyses identified gene-level associations with linear growth and breastfeeding, including annotated hits such as arnC in multiple clades. Machine learning found microbial species predictive of linear growth, while longitudinal genome comparisons showed greater within-strain genomic instability and prophage dynamics in children with declining length‑for‑age Z scores. PacBio with metaMDBG produced the highest-quality and most cost‑effective cMAGs in this study.

Conclusion:
High-throughput long‑read metagenomics enables recovery of near-complete gut genomes at scale, allowing species‑constrained pangenome and mGWAS analyses that reveal gene- and genome-level microbial associations with pediatric linear growth and breastfeeding status.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Culture-independent meta-pangenomics enabled by long-read metagenomics reveals associations with pediatric undernutrition

First author:
Minich JJ

Journal:
Cell

DOI:
10.1016/j.cell.2025.08.020

Reference:
Minich JJ, Allsing N, Din MO, et al. Culture-independent meta-pangenomics enabled by long-read metagenomics reveals associations with pediatric undernutrition. Cell. 2025;188:1–21. https://doi.org/10.1016/j.cell.2025.08.020

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/culture-independent-metapangenomics-reveals-gut-genome-links-to-child-growth

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-09-10.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited sections cover long-read versus short-read performance, generation of complete MAGs (cMAGs) and circular genomes, longitudinal associations between genome dynamics and LAZ, pangenome and gene-level associations with growth and breastfeeding, prophage integration findings, environmental/geographic influences on
- transcript topics: Global malnutrition and LAZ definitions; Limitations of short-read sequencing for MAG recovery; Long-read metagenomics in Malawi cohort (PacBio and ONT); Generation of complete MAGs (cMAGs) and circular genomes; Longitudinal genome instability and LAZ decline; Pangenome analyses and gene-level associations with linear growth and breastfeeding (arnC, Prevotella, Megasphaera, Faecalibacterium, etc.)

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Long-read sequencing (PacBio/ONT) yields 44–64× more complete MAGs per Gbp than short-read Illumina; SR yielded 0 complete genomes in this dataset.
- Recovered 986 complete cMAGs (839 circular), representing 363 species and 74 putative novel species (ANI < 95%).
- Genome instability (within-strain ANI divergence) is associated with declining LAZ, with detectable changes around ~5.5 months.
- Pangenome analyses and microbial GWAS reveal gene-level associations with linear growth and breastfeeding; arnC and related genes show predictive associations across several genera
- Breastfeeding status linked to higher prophage integrations in gut bacteria; temperate phages can carry metabolic genes and influence bacterial traits relevant to gut health.
- Environmental context (village) shapes strain-level gene content; Megasphaera clusters and gene-content variation show geographic association; integrated view via PanKmer and funct

QC result: Pass.

132: Transcriptome classifiers predict docetaxel sensitivity in advanced prostate cancer

Gustavo Barra — Tue, 09 Sep 2025 08:34:14 +0000

Grist E et al., Cell - Large-scale transcriptome profiling of 1,523 diagnostic prostate tumors from randomized STAMPEDE phase 3 trials linked expression signatures and immunohistochemistry to 14-year survival. The Decipher RNA classifier was both prognostic and predicted survival benefit from docetaxel in metastatic disease, and a transcriptome-based PTEN inactivity classifier identified docetaxel-sensitive, metabolically perturbed tumors. High tumor androgen receptor signaling associated with longer survival while increased proliferation predicted shorter survival. These results support clinical implementation of transcriptome classifiers to guide treatment selection in advanced prostate cancer. Key terms: prostate cancer, transcriptome, Decipher, docetaxel, PTEN.

Study Highlights:
The study generated transcriptome-wide expression profiles and Ki-67/PTEN immunohistochemistry for 1,523 patients (832 metastatic) from STAMPEDE phase 3 trials with 14-year follow-up. High Decipher scores were prognostic and pre-specified predictive for docetaxel benefit in metastatic disease (interaction p = 0.039). A PTEN_loss_Liu transcriptome classifier identified PTEN-inactive tumors that had shorter survival on hormone therapies but significant survival benefit from docetaxel (interaction p = 0.002). Tumor AR signaling associated with longer survival and proliferation signatures (and Ki-67) with shorter survival.

Conclusion:
Clinical-grade transcriptome classifiers (notably Decipher and a PTEN inactivity signature) predict which metastatic prostate cancers derive survival benefit from docetaxel and could be implemented to improve treatment selection.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Tumor transcriptome-wide expression classifiers predict treatment sensitivity in advanced prostate cancers

First author:
Grist E

Journal:
Cell

DOI:
10.1016/j.cell.2025.07.042

Reference:
Grist E., Dutey-Magni P., Parry M.A., et al. Tumor transcriptome-wide expression classifiers predict treatment sensitivity in advanced prostate cancers. Cell. 2025;188:1–18. https://doi.org/10.1016/j.cell.2025.07.042

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/tumor-transcriptome-classifiers-predict-treatment-sensitivity-in-advanced-prostate-cancer

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-09-09.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited transcript segments describing the STAMPEDE biomarker cohort, transcriptome-wide profiling methods, prognostic vs predictive biomarkers, Decipher predicting docetaxel benefit, PTEN inactivity predicting docetaxel sensitivity, statistical design and level of evidence, and study limitations.
- transcript topics: Clinical treatment landscape for metastatic prostate cancer (ADT, docetaxel, abiraterone); Formalin-fixed, paraffin-embedded tissue transcriptome profiling and 59 signatures; Prognostic vs predictive biomarkers in STAMPEDE trials; Decipher classifier as predictor of docetaxel benefit (interaction with survival, p = 0.039); PTEN inactivity (PTEN_loss_Liu) as predictor of docetaxel sensitivity (interaction p = 0.002); Overlap of Decipher and PTEN inactivity and implications for treatment

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- STAMPEDE biomarker cohort included 1,523 patients with metastatic (832) or non-metastatic (691) disease and up to 14 years of survival follow-up
- Molecular data were generated from FFPE diagnostic tissue using clinical-grade pan-transcriptome microarrays testing 59 expression signatures
- Decipher score was prognostic and predicted survival benefit from docetaxel in metastatic disease (biomarker–docetaxel interaction p = 0.039)
- PTEN_loss_Liu/PTEN-inactivation signature predicted docetaxel sensitivity in metastatic disease (biomarker–docetaxel interaction p = 0.002; RMST and HR improvements described)
- Combined high Decipher and PTEN inactivity identified tumors with the greatest docetaxel sensitivity (metastatic disease: HR 0.55, 99% CI 0.34–0.89)
- The study adhered to level 1B evidence guidelines for prospective-retrospective biomarker discovery/evaluation

QC result: Pass.

131: Cryptic plasmid pBI143: a small element with outsized presence in the human gut

Gustavo Barra — Mon, 08 Sep 2025 09:00:13 +0000

Fogarty EC et al., Cell (187:1206–1222, February 29, 2024) - This episode summarizes Fogarty et al. 2024, which characterizes pBI143, a 2.7 kb cryptic plasmid that is highly prevalent and abundant across industrialized human gut metagenomes. The team combines large-scale metagenomics, isolate experiments, structural analyses, qPCR assays, and gnotobiotic mouse work to map pBI143’s distribution, transmission, host range, evolutionary constraints, and responses to stress. Key terms: pBI143, cryptic plasmid, human gut microbiome, plasmid prevalence, IBD.

Study Highlights:
pBI143 is a ubiquitous, highly abundant 2.7 kb cryptic plasmid detected in the majority of gut metagenomes from industrialized populations and is estimated to be ~14 times more numerous than crAssphage by copy number. It is typically monoclonal within individuals, often vertically transmitted from mother to infant, and can transfer among Bacteroidales species. Population variation is concentrated at specific sites under strong purifying selection and localized amino-acid changes cluster near MobA DNA-binding regions. pBI143 copy number increases during oxidative stress in culture and is higher in metagenomes from individuals with IBD, and it can occasionally acquire additional cargo genes.

Conclusion:
pBI143 is a highly successful human-gut-restricted cryptic plasmid that behaves largely as a monoclonal, transmissible genetic element under purifying selection, with potential uses as a sensitive human fecal marker and as an indicator of microbial stress in the gut.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
A cryptic plasmid is among the most numerous genetic elements in the human gut

First author:
Fogarty EC

Journal:
Cell (187:1206–1222, February 29, 2024)

DOI:
10.1016/j.cell.2024.01.039

Reference:
Fogarty EC, Schechter MS, Lolans K, Sheahan ML, Veseli I, Moore RM, et al. A cryptic plasmid is among the most numerous genetic elements in the human gut. Cell. 2024;187:1206–1222. https://doi.org/10.1016/j.cell.2024.01.039

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/pbi143-the-human-guts-hidden-heavyweight

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-09-08.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited transcript sections describing pBI143 biology (size, mobA/repA), global prevalence and host range, monoclonality and maternal transmission, horizontal transfer experiments, structural/variational analyses, oxidative stress response, cargo acquisition, and clinical/environmental implications.
- transcript topics: pBI143 basic features (size, mobA and repA); global prevalence and host range in Bacteroidales; monoclonality, priority effects, and maternal transmission; horizontal transfer between Bacteroidales species (transfer assays); mutational landscape and AlphaFold-based structure mapping; oxidative stress response and copy-number dynamics

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- pBI143 is ~2,747 bp with two annotated genes, mobA and repA
- Three versions of pBI143 exist with high overall identity; repA varies among versions
- pBI143 is highly prevalent in industrialized populations (roughly 73% across 4,516 gut metagenomes; up to 92% in Japan and 86% in the USA)
- pBI143 makes up approximately 0.1%–3.5% of metagenomic reads in carriers (with high coverage in carriers)
- pBI143 is largely monoclonal within individuals and is vertically transmitted from mother to infant via priority effects
- pBI143 can transfer between Bacteroidales species (demonstrated via conjugation experiments)

QC result: Pass.

130: Genetics + CRISPR to Map Obesity and Fat Distribution

Gustavo Barra — Sun, 07 Sep 2025 12:37:56 +0000

Baya NA et al., The American Journal of Human Genetics - This episode summarizes a multi-modal study that integrates exome sequencing in 402,375 UK Biobank participants with CRISPR knockdown in human white adipocytes to nominate genes and pathways that alter overall adiposity and fat distribution. Key terms: obesity, fat distribution, exome sequencing, CRISPR knockdown, adipocytes.

Study Highlights:
The authors performed rare-variant (MAF<1%) exome-wide association testing across nine obesity- and depot-specific fat traits in 402,375 European-ancestry UK Biobank participants, identifying 19 exome-wide significant genes and 50 additional genes at FDR≤1% (69 total). They prioritized 14 genes for CRISPR-Cas9 knockdown in a human white adipocyte cell line and measured lipid accumulation with BODIPY staining and high-content imaging. Knockdown of PPARG and SLTM significantly decreased lipid accumulation, while COL5A3 knockdown increased it; EXOC7 and TRIP10 had nominal increases. Integrating population genetics, allelic series, longitudinal age-of-onset, and transcriptomics highlighted candidate therapeutic avenues to modulate adiposity and fat distribution.

Conclusion:
Combining large-scale human genetic association with targeted functional screens in human adipocytes identifies high-confidence genes and mechanisms—such as adipogenesis regulation and extracellular matrix components—that can inform therapeutic strategies to alter body fat amount and distribution.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Combining evidence from human genetic and functional screens to identify pathways altering obesity and fat distribution

First author:
Baya NA

Journal:
The American Journal of Human Genetics

DOI:
10.1016/j.ajhg.2025.08.013

Reference:
Baya NA, SurErdem I, Venkatesh SS, et al.; Claussnitzer M, Palmer DS, Lindgren CM. Combining evidence from human genetic and functional screens to identify pathways altering obesity and fat distribution. The American Journal of Human Genetics. 2025;112:1–22. https://doi.org/10.1016/j.ajhg.2025.08.013

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/combining-evidence-from-human-genetic-and-functional-screens-to-identify-pathways-altering-obesity-and-fat-distribution

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-09-07.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited transcript sections describing UK Biobank exome sequencing and nine fat-trait phenotypes, identification of candidate genes, CRISPR-Cas9 functional validation in human white adipocytes, key gene findings (PPARG, SLTM, COL5A3), monotonic dose–response relationships, and obesity-age-onset analyses.
- transcript topics: UK Biobank exome sequencing design and nine fat-related traits; Rare-variant gene-level associations and PoPS integration; CRISPR-Cas9 knockdown in human white adipose tissue cells and BODIPY lipid readouts; Key genes PPARG, SLTM, COL5A3 and their lipid-accumulation effects; Monotonic allelic series and dose-response relationships; Longitudinal obesity age-of-onset analyses (MC4R, SLTM)

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- UK Biobank exome sequencing on ~402,375 European-ancestry individuals across nine obesity-related traits
- 69 genes significantly associated with fat distribution; 19 exome-wide significant; 50 additional at BH FDR ≤ 1%
- 14 genes selected for CRISPR-Cas9 knockdown in differentiated human white adipose tissue cells
- PPARG and SLTM knockdown decreased lipid accumulation; COL5A3 knockdown increased lipid accumulation
- Monotonic allelic series observed in 22 genes for ultra-rare variants
- SLTM loss-of-function variants associated with higher BMI in humans; SLTM knockdown decreased lipid accumulation in adipocytes

QC result: Pass.

129: NPIP — Structural variation, selection, and paralog diversification

Gustavo Barra — Sat, 06 Sep 2025 12:22:00 +0000

Dishuck PC et al., Cell Genomics - Using 169 long-read human haplotypes and 1.4 billion full-length cDNA reads, Dishuck et al. resolve the complex NPIP gene family on chromosome 16, revealing extreme copy-number and structural variation, widespread interlocus gene conversion and inversions, ongoing positive selection at specific paralogs, and paralog-specific full-length gene models with tissue-biased expression. Key terms: NPIP, segmental duplications, positive selection, long-read sequencing, gene conversion.

Study Highlights:
The authors use haplotype-resolved long-read assemblies and Iso-Seq to catalog 4,665 NPIP copies across 169 haplotypes and define 28 paralogs. They detect frequent interlocus gene conversion and multiple large inversion polymorphisms mediated by NPIP duplications. Population-level tests (Tajima’s D, nSL) reveal ongoing positive selection at several paralogs while Iso-Seq uncovers paralog-specific ORFs and tissue-biased expression, with 56% of common isoforms previously unreported. VNTR expansion in a human-specific NPIPB subfamily predicts a β-helix domain and novel signal peptide evolution.

Conclusion:
High-resolution pangenomic sequencing shows NPIP is an exceptionally dynamic, human-specific gene family with structural rearrangements, gene conversion, and positive selection shaping paralog-specific gene models and expression; these resolved paralogs now provide targets for functional and clinical follow-up.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Structural variation, selection, and diversification of the NPIP gene family from the human pangenome

First author:
Dishuck PC

Journal:
Cell Genomics

DOI:
10.1016/j.xgen.2025.100977

Reference:
Dishuck PC, Munson KM, Lewis AP, Dougherty ML, Underwood JG, Harvey WT, Hsieh P, Pastinen T, Eichler EE. Structural variation, selection, and diversification of the NPIP gene family from the human pangenome. Cell Genomics. 2025;5:100977. doi:10.1016/j.xgen.2025.100977

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/structural-variation-and-diversification-of-the-npip-gene-family-from-the-human-pangenome

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-09-06.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited transcript sections describing NPIP copy-number variation, long-read pangenome mapping, interlocus gene conversion (IGC) and inversion polymorphisms, resurrection/open reading frames of paralogs, brain/testis protein innovations, NPIP-PKD1 fusion transcripts, and population-genetic selection signals (Tajima's D
- transcript topics: NPIP copy-number variation across humans and primates; Long-read sequencing and pangenome mapping of NPIP; Interlocus gene conversion (IGC) and inversion polymorphisms; Resurrection of NPIP pseudogenes and open reading frames; Human-specific protein innovations: signal peptide and VNTR beta-helix; NPIP-PKD1 fusion transcripts

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Copy-number expansion in humans: 21–33 NPIP copies per haploid genome (vs macaque single copy).
- Extreme CNV across 169 haplotypes; 4,665 total NPIP copies across haplotypes; occurrences of interlocus gene conversion (IGC) and inversion polymorphisms drive region variation.
- Four paralogs (B1, A4, B10, B14) maintain open reading frames and actively produce transcripts.
- Two human-specific innovations: novel signal peptide highly expressed in testes; expanded VNTR encoding a beta-helix with brain expression.
- NPIP-PKD1 fusion transcripts yield functional multi-exonic proteins up to 843 amino acids long.
- Ongoing positive selection on NPIP copies evidenced by Tajima's D and NSL statistics.

QC result: Pass.

128: L1 elements, chromatin and CRISPRi

Gustavo Barra — Fri, 05 Sep 2025 08:00:00 +0000

Adami A et al., Cell Genomics - This episode covers analyses of L1 retrotransposon subfamilies (L1PA2/3/4, L1HS), their chromatin signatures (including H3K4me3), and perturbation experiments using CRISPRi. The source text includes comparative plots across primates and gene-level readouts such as PPP1R1C. Key terms: L1 retrotransposon, L1PA2, L1HS, H3K4me3, CRISPRi.

Study Highlights:
The paper maps H3K4me3 and related chromatin signals at L1 subfamilies including L1HS and L1PA2/3/4 and presents comparative timelines across primates. Targeted CRISPRi against L1 elements was used and compared with controls, with gene-level examples shown (PPP1R1C). Figures include genomic tracks, heatmaps, and quantification of signal changes tied to specific L1 subfamilies.

Conclusion:
L1 subfamilies carry distinct H3K4me3-associated chromatin signatures and can be transcriptionally modulated by CRISPRi, with measurable effects on nearby gene expression. The data and comparative analyses across primates highlight subfamily-specific regulatory potential of L1 elements.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
LINE-1 retrotransposons mediate cis-acting transcriptional control in human pluripotent stem cells and regulate early brain development

First author:
Adami A

Journal:
Cell Genomics

DOI:
10.1016/j.xgen.2025.100979

Reference:
Adami A., Garza R., Gerdes P., Johansson P.A., Dorazehi F., Koutounidou S., et al.. LINE-1 retrotransposons mediate cis-acting transcriptional control in human pluripotent stem cells and regulate early brain development. Cell Genomics, 5, 100979. (2025). https://doi.org/10.1016/j.xgen.2025.100979

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/line1-promoters-orchestrate-early-human-brain-development

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-09-05.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript's presentation of L1 biology, promoter activity, CRISPRi silencing of young L1 promoters (L1HS/L1PA2), downstream gene/lncRNA effects (PPP1R1C, Len NC_00648), organoid differentiation outcomes, evolutionary context, and methodological limitations, cross-checking these with the canonical article.
- transcript topics: L1 biology and chromatin signatures; Long-read sequencing and transcript mapping to resolve L1 copies; CRISPR interference (CRISPRi) silencing of L1 promoters; L1 antisense promoters driving PPP1R1C and Len NC_00648 transcripts; Organoid models and neural progenitor differentiation; Evolutionary context of L1 subfamilies (L1HS, L1PA2/3/4)

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- L1HS and L1PA subfamilies show H3K4me3-associated chromatin signals in human cells
- CRISPRi targeting of evolutionarily young L1 promoters (L1HS/L1PA2) silences transcription locally
- L1 elements function as alternative promoters for a set of genes including PPP1R1C and the lncRNA Len NC_00648
- Approximately 100 protein-coding genes and lncRNAs are driven by L1 antisense promoters in human pluripotent stem cells
- Silencing L1 promoters affects differentiation into cerebral organoids, yielding smaller organoids with impaired structure
- Neural progenitor cell transcriptional programs are disrupted upon L1 silencing

QC result: Pass.

127: OncoGAN: Generating Synthetic Cancer Genomes with AI

Gustavo Barra — Thu, 04 Sep 2025 08:59:58 +0000

Díaz-Navarro A et al., Cell Genomics - OncoGAN is a multimodel generative AI pipeline that simulates realistic, privacy-preserving cancer genomes (VCFs, CNAs, SVs) across eight tumor types to support benchmarking and training of genome-analysis tools. Key terms: OncoGAN, synthetic genomes, generative AI, mutational signatures, privacy-preserving.

Study Highlights:
OncoGAN combines GANs, TVAEs, CTGAN/CTAB-GAN+ and sampling to model donor characteristics, mutational signatures, genomic positions, VAFs, CNAs and SVs and generates realistic synthetic cancer genomes. The pipeline reproduces tissue-specific mutational patterns and driver correlations while ensuring minimal overlap with training donors to preserve privacy. Augmenting DeepTumour training sets with OncoGAN-simulated donors improved classification accuracy, and the authors released 800 simulated genomes for community use.

Conclusion:
OncoGAN produces shareable, privacy-preserving synthetic cancer genomes that closely recapitulate real tumor features and can improve development and benchmarking of cancer-genome analysis tools.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
In silico generation of synthetic cancer genomes using generative AI

First author:
Díaz-Navarro A

Journal:
Cell Genomics

DOI:
10.1016/j.xgen.2025.100969

Reference:
Díaz-Navarro A, Zhang X, Jiao W, Wang B, Stein L. In silico generation of synthetic cancer genomes using generative AI. Cell Genomics. 2025;5:100969. https://doi.org/10.1016/j.xgen.2025.100969

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/in-silico-generation-of-synthetic-cancer-genomes-using-generative-ai

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-09-04.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited core methodology and results sections describing the OncoGAN/OncoGAN-like Ankogan pipeline, privacy safeguards, genome discretization, mutational signatures, driver-detection performance, DeepTumour validation, data accessibility, and stated limitations.
- transcript topics: OncoGAN/Ankogan pipeline architecture (GANs, TVAEs, and random sampling); Privacy-preserving data generation (independent location and context generation; final assembly); Genome discretization and position mapping (3Gbp to ~30Mbp; binning and expansion); Mutational signatures and their recovery (SBS4, SBS9; SigProfilerExtractor validation); Driver mutation analysis with ActiveDriverWGS; DeepTumour tissue-of-origin prediction and impact of synthetic data

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- OncoGAN uses a multimodel ensemble (GANs, TVAEs, random sampling) to generate eight-tumor-type synthetic cancer genomes.
- Privacy safeguards: mutation location and trinucleotide context are generated independently and combined at the end; 100 nt window check verifies context against real genome; only
- Genome discretization compresses 3,000,000,000 bp to 30,000,000 bp and bins into over 100,000 segments (with explicit mention of 105 bins of 0.3 Mbp in the canonical article).
- Mutational signatures SBS4 and SBS9 are reproduced in synthetic data; SigProfilerExtractor recapitulates the real donor distributions.
- ActiveDriverWGS detects ~89% of coding driver genes in real data and ~87% in synthetic OncoGAN data.
- DeepTumour achieves nearly 100% tissue-of-origin prediction accuracy on synthetic genomes for most tumor types; synthetic data improves training when mixed with real data.

QC result: Pass.

126: Smith-Magenis Syndrome: Chromatin Rewiring to Hyperexcitable Neurons

Gustavo Barra — Wed, 03 Sep 2025 08:52:39 +0000

Lee Y et al., The American Journal of Human Genetics - This episode reviews a study using hiPSC-derived 2D cortical neurons and 3D cortical organoids from individuals with del(17)p11.2 (Smith-Magenis syndrome) to map chromatin, transcriptional, developmental, and electrophysiological consequences of the deletion. Key terms: Smith-Magenis syndrome, del(17)p11.2, hiPSC organoids, chromatin topology, neuronal hyperexcitability.

Study Highlights:
The authors show that del(17)p11.2 induces local TAD fusion on chromosome 17 and genome-wide chromatin miswiring in hiPSCs and cortical organoids, with widespread transcriptional dysregulation. SMS organoids display reduced growth, enlarged PAX6+ ventricles, impaired progenitor cell-cycle progression, and accelerated neuronal maturation. In 2D cortical neurons, SMS cells exhibit early accelerated dendritic growth, increased excitatory synapse density, and intrinsic hyperexcitability linked to reduced voltage-gated potassium conductance. Together, the models recapitulate neuroanatomical and neurophysiological features of SMS and identify candidate molecular and cellular mechanisms.

Conclusion:
del(17)p11.2 disrupts 3D chromatin architecture and transcriptional programs, impairing progenitor proliferation and promoting neuronal hyperexcitability, which hiPSC-derived 2D and 3D models faithfully recapitulate and that point to potassium-channel and cell-cycle pathways as potential intervention targets.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Molecular and developmental deficits in Smith-Magenis syndrome human stem cell-derived cortical neural models

First author:
Lee Y

Journal:
The American Journal of Human Genetics

DOI:
10.1016/j.ajhg.2025.07.020

Reference:
Lee Y.-J., Chang Y.-T., Cho Y., Kowalczyk M., Dragoiescu A., Pacis A., Kailasam S., Lefebvre F., Zhang Q., Gao X., Huang W.-H. (2025). Molecular and developmental deficits in Smith-Magenis syndrome human stem cell-derived cortical neural models. The American Journal of Human Genetics 112, 1–25. https://doi.org/10.1016/j.ajhg.2025.07.020

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/molecular-and-developmental-deficits-in-smith-magenis-syndrome-human-stem-cell-derived-cortical-neural-models

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-09-03.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited transcript sections covering human iPSC-based SMS models (2D neurons and 3D organoids), 3D genome topology (Hi-C/TAD fusion), transcriptional changes (snRNA-seq/bulk RNA-seq), organoid growth and ventriculomegaly, NPC proliferation/cell-cycle defects, 2D neuron maturation and hyperexcitability with potassium-ch
- transcript topics: Human iPSC-derived SMS models (2D cortical neurons and 3D cortical organoids); 3D genome architecture and chromatin topology changes (Hi-C, TAD fusion, trans effects); Global transcriptional dysregulation across multiple cortical cell types (snRNA-seq and bulk RNA-seq); Organoid growth impairment and ventriculomegaly-like phenotypes with NPC proliferation defects; NPC cell-cycle perturbations and G1 arrest signatures; Neuron maturation and dendritic expansion with early excitatory synapse changes

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 8
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- del(17)p11.2 in SMS hiPSCs and cortical organoids alters 3D chromatin topology (local TAD fusion and global miswiring)
- Widespread transcriptional dysregulation across multiple cortical cell types (trans effects observed beyond deleted region)
- SMS cortical organoids show reduced growth and ventriculomegaly-like ventricles due to impaired NPC proliferation/cell-cycle progression
- SMS 2D cortical neurons show accelerated dendritic growth followed by neuronal hyperexcitability linked to reduced potassium conductance
- Reduced voltage-gated potassium currents (K fast and K slow) accompany hyperexcitability; SLC family transporters involved
- POTEI and POTEF are primate-specific protocadherin-related genes with altered expression in SMS organoids

QC result: Pass.

125: GP2: A Global Roadmap for Parkinson’s Genetics

Gustavo Barra — Tue, 02 Sep 2025 08:48:00 +0000

Blauwendraat C et al., The American Journal of Human Genetics - This episode reviews a perspective on the Global Parkinson’s Genetics Program (GP2), a coordinated international effort to expand Parkinson disease genetic discovery across underrepresented populations by combining large-scale genotyping, sequencing, capacity building, and open data sharing. Key terms: Parkinson's disease, genetics, global collaboration, diversity, data sharing.

Study Highlights:
GP2 is a five-year international initiative that aims to generate and harmonize genetic data from a global cohort, prioritizing underrepresented populations and equitable collaboration. The program works with 275 sites and reports data and samples from 265,000 subjects committed to GP2 as of May 2025, with ~83,000 individuals included in a recent data release. Key components include centralized data generation, cloud-based harmonized analysis, extensive training (250+ trainees and many courses), and regional capacity-building such as biorepositories. Lessons learned emphasize stable long-term funding, balancing centralized efficiency with decentralized equity, addressing legal and operational complexity, and promoting transparent, democratized access to data.

Conclusion:
GP2 demonstrates that large-scale, globally inclusive genetics efforts can accelerate discovery, refine biological definitions of Parkinson disease, and enable precision therapeutic strategies; sustained funding, capacity building, and transparent data sharing are critical to its success.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Tackling a disease on a global scale, the Global Parkinson’s Genetics Program, GP2: A new generation of opportunities

First author:
Blauwendraat C

Journal:
The American Journal of Human Genetics

DOI:
10.1016/j.ajhg.2025.07.014

Reference:
Blauwendraat C., Noyce A.J., Mata I.F., et al., Tackling a disease on a global scale, the Global Parkinson’s Genetics Program, GP2: A new generation of opportunities. The American Journal of Human Genetics (2025). https://doi.org/10.1016/j.ajhg.2025.07.014

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/tackling-a-disease-on-a-global-scale-the-global-parkinsons-genetics-program-gp2-a-new-generation-of-opportunities

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-09-02.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited transcript sections covering GP2 goals and structure, pillars, data sharing model, key genetic findings (including RS3115534G in GBA1), pleomorphic risk loci, biomarker context (alpha-synuclein SAA), governance/no-surprises policy, training, and future directions.
- transcript topics: Global diversity and PD genetics need; GP2 structure and four actionable areas; Data democratization and cloud analysis; Training and capacity building; Key genetic findings and pleomorphic risk loci; Biomarkers and alpha-synuclein SAA

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- GP2 consists of 275 research groups across >60 countries.
- Data and samples from 265,000 subjects committed to GP2 as of May 2025.
- 83,000 individuals in GP2 data release 10.
- GP2 pillars: global collaboration and capacity building; democratizing data; growing next generation leaders; applying transformative genetic methods.
- No-surprises policy with a Project Proposal Working Group guiding cross-cohort analysis.
- African-ancestry risk factor RS3115534G disrupts an intronic branch point in GBA1, enabling GBA1-based clinical trials.

QC result: Pass.

124: Omnigenic Architecture and Core Genes in Ulcerative Colitis

Gustavo Barra — Mon, 01 Sep 2025 09:04:00 +0000

Ratajczak F et al., The American Journal of Human Genetics - This study uses the Speos graph machine-learning framework on multi-modal molecular networks to identify core genes for complex traits, focusing on ulcerative colitis (UC). It shows tissue-specific core-gene expression, coordinated regulation of core genes after perturbation, and frequent non-linear interactions in co-perturbations. Key terms: omnigenic, core genes, ulcerative colitis, Speos, perturbation.

Study Highlights:
Using Speos, the authors identify confident core-gene sets for UC that are enriched for tissue-specific expression and disease-relevant network connections. Genome-scale perturbation data show that about one-third of knockdown or overexpression perturbations differentially affect core versus peripheral genes, a pattern not seen for GWAS or random gene sets. Core genes respond in a concerted manner across traits and cell lines, while co-perturbation simulations predict frequent non-linear genetic interactions between core genes. These results extend the omnigenic model by highlighting coordinated regulation and interaction among core genes as mechanisms that can contribute to heritability.

Conclusion:
Core genes occupy central, tissue-relevant positions in molecular networks and are coherently regulated by perturbations across the genome; non-additive interactions among core genes add a further layer of complexity to the omnigenic model and to how peripheral variation may influence disease.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Exploring the omnigenic architecture of selected complex traits

First author:
Ratajczak F

Journal:
The American Journal of Human Genetics

DOI:
10.1016/j.ajhg.2025.07.006

Reference:
Ratajczak F., Heinig M., Falter-Braun P. (2025). Exploring the omnigenic architecture of selected complex traits. The American Journal of Human Genetics 112, 1–23. https://doi.org/10.1016/j.ajhg.2025.07.006

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/exploring-the-omnigenic-architecture-of-selected-complex-traits

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-09-01.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited transcript sections describing the omnigenic model, core vs peripheral genes, Speos multi-modal network, 72-tissue expression features, LINCS perturbation analyses, GEARS co-perturbations, cross-disease validation (CAD and SCZ), mouse knockout and human tissue expression evidence, and clinical implications for
- transcript topics: Omnigenic model overview with core vs peripheral genes; Speos: multi-modal network construction and core-gene identification; Immune-tissue expression of UC core genes versus colon; LINCS perturbation analyses showing concerted core gene regulation; GEARS co-perturbation simulations: non-additive interactions (neomorphism, suppression); Cross-trait validation: CAD and schizophrenia architectures

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- UC core genes identified by Speos: 693 highly confident core-gene candidates for UC
- Core genes are tissue-relevant, with high expression in immune tissues (blood, spleen, EBV-transformed lymphocytes) rather than the colon
- One-third of perturbations in LINCS data produce discriminative effects on core genes versus peripheral genes
- Co-perturbation simulations reveal non-linear interactions among core genes (neomorphism and suppression)
- The same core-periphery architecture is observed in CAD and schizophrenia, indicating a potentially universal omnigenic pattern
- Peripheral HSPs (e.g., INAVA, PARK7, MAML2) show GWAS signals but lack tissue-specific core expression, illustrating peripheral regulation

QC result: Pass.

123: Dominant-negative ATP5F1A variants and uncoupled oxidative phosphorylation

Gustavo Barra — Sun, 31 Aug 2025 11:50:11 +0000

Fielder SM et al et al., EMBO Molecular Medicine - This episode examines a study that identifies de novo heterozygous missense variants in ATP5F1A that cause developmental and movement disorders by destabilizing mitochondrial complex V. Functional C. elegans modeling and patient-cell assays reveal a dominant negative mechanism and uncoupled oxidative phosphorylation. Key terms: ATP5F1A, complex V, oxidative phosphorylation, dominant negative, mitochondrial disease.

Study Highlights:
Six probands carry four de novo heterozygous ATP5F1A missense variants located at α:β or α:γ contact points of the F1 ATP synthase. CRISPR knock-ins in C. elegans show the variants are damaging and act dominantly, with phenotypes suppressed by extra wild-type copies. Patient fibroblasts and lymphoblastoid cells display reduced complex V abundance and activity, and proband fibroblasts show increased oxygen consumption but decreased membrane potential and ATP consistent with uncoupling. Proteomics, BN-PAGE, and biochemical assays support destabilization of complex V as the pathophysiologic mechanism.

Conclusion:
De novo heterozygous ATP5F1A missense variants can act as dominant negative alleles that reduce complex V stability and activity and cause uncoupled oxidative phosphorylation, producing a spectrum of persistent neurological phenotypes; integrated functional studies are required to classify such variants.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Dominant negative ATP5F1A variants disrupt oxidative phosphorylation causing neurological disorders

First author:
Fielder SM et al

Journal:
EMBO Molecular Medicine

DOI:
10.1038/s44321-025-00290-8

Reference:
Fielder SM et al., Dominant negative ATP5F1A variants disrupt oxidative phosphorylation causing neurological disorders. EMBO Mol Med (2025). DOI:10.1038/s44321-025-00290-8

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/dominantnegative-atp5f1a-variants-uncouple-complex-v-and-drive-neurological-disease

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-08-31.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript's coverage of structure, variants, and function of ATP5F1A; dominant negative mechanism; C. elegans modeling; patient-cell metabolism; comparison to Arg207His; clinical implications.
- transcript topics: ATP synthase structure and Complex V; ATP5F1A dominant negative variants; Variant localization at α:β and α:γ interfaces; C. elegans functional modeling and rescue; Proteomics and BN-PAGE analyses of patient cells; Mitochondrial respiration and uncoupled oxidative phosphorylation

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Six probands with heterozygous de novo ATP5F1A variants presented with developmental delay, intellectual disability, and movement disorders.
- Variants map to contact points between the α-subunit and β- or γ-subunits (α:β and α:γ) of the F1 complex.
- In vivo functional studies in C. elegans show these variants are damaging via a dominant negative mechanism; phenotypes are suppressible by extra wild-type copies.
- Proband-derived cells show reduced complex V abundance and activity; ATP5F1A and OSCP-related subunits are decreased.
- Mitochondrial physiology reveals uncoupled oxidative phosphorylation: increased oxygen consumption with decreased membrane potential and ATP.
- Arg207His is a previously reported ATP5F1A variant with neonatal onset and clinical resolution by 18 months, contrasting with the current variants.

QC result: Pass.

122: Patient stratification reveals the molecular basis of disease co-occurrences

Gustavo Barra — Sat, 30 Aug 2025 09:01:22 +0000

Urda-García B et al., PNAS - This episode discusses a PNAS study that builds disease similarity networks from public RNA-seq data and shows that stratifying patients into 'meta-patients' uncovers molecular mechanisms behind many medically observed comorbidities. Key terms: transcriptomics, comorbidity, disease networks, patient stratification, immune system.

Study Highlights:
The authors used uniformly processed RNA-seq from 45 diseases to build a Disease Similarity Network (DSN) and a Stratified Similarity Network (SSN) that includes patient subgroups (meta-patients). The DSN recapitulates 46.2% of epidemiological comorbidities and the SSN raises recall to 64.13%, while maintaining precision. Most captured comorbidities implicate immune system pathways and shared dysregulated Reactome pathways such as ECM, metabolism, and signal transduction. Meta-patients reveal subgroup-specific comorbidity links and increase detection power, especially for heterogeneous diseases.

Conclusion:
Gene expression–based disease networks, enhanced by patient stratification, explain a large fraction of known comorbidities and provide molecular hypotheses—predominantly immune-related—that can guide personalized management and further study.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Patient stratification reveals the molecular basis of disease co- occurrences

First author:
Urda-García B

Journal:
PNAS

DOI:
10.1073/pnas.2421060122

Reference:
Urda-García B, Sánchez-Valle J, Lepore R, Valencia A. Patient stratification reveals the molecular basis of disease co-occurrences. PNAS. 2025;122(35):e2421060122. doi:10.1073/pnas.2421060122

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/patient-stratification-reveals-the-molecular-basis-of-disease-co-occurrences

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-08-30.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited sections cover: comorbidity concept, differential expression strategy, DSN/SSN methodology, meta-patient stratification, key molecular mechanisms (immune system and ECM), inverse comorbidities (Huntington's with cancers), Down syndrome heterogeneity, and the public web resource.
- transcript topics: Comorbidity concepts and data sources; RNA-seq differential expression and disease fingerprinting; Disease Similarity Network (DSN) construction; Stratified Similarity Network (SSN) and meta-patients; Immune system and ECM pathways in comorbidities; Inverse comorbidity and Huntington's disease example

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- DSN recalls 46.2% of known epidemiological comorbidities
- SSN recalls 64.1% (meta-patients) of epidemiological associations
- 95.2% of epidemiological interactions share at least one immune system pathway
- ECM pathways and related metabolic/signal pathways are commonly altered in comorbidities

Chapters

(00:00:00) - Deep Dive: The molecular logic of disease co-occurrences
(00:04:43) - RNA Sequencing: the game changer
(00:06:55) - The Nature of the Disease similarity network
(00:09:52) - Discovery of the disease network
(00:12:56) - The Social Science Network (SSN) and the Metapat
(00:16:56) - Measuring the molecular basis of diseases

121: G-quadruplexes, BRCA2, and a Helicase Weak Spot

Gustavo Barra — Fri, 29 Aug 2025 09:07:36 +0000

Keahia DL et al., Proceedings of the National Academy of Sciences (PNAS) - This study shows that G-quadruplex (G4) DNA structures are hotspots of replication stress and mutagenesis in BRCA2-deficient cerebellar granule cell progenitors (GCPs), driving SHH-subgroup medulloblastoma, and identifies upregulation of the G4-resolving helicase PIF1 in tumors. Key terms: BRCA2, G-quadruplexes, PIF1, medulloblastoma, granule cell progenitors.

Study Highlights:
Deletion of Brca2 exons 3–4 combined with Trp53 loss in mice produced fully penetrant SHH medulloblastomas that resemble proliferating GCPs. Whole-genome sequencing of tumors revealed structural variant breakpoints significantly overlapping putative and experimentally mapped G4-forming sequences. BRCA2-deficient GCPs show reduced replication speed and increased cell death upon G4 stabilization with pyridostatin, and tumor cells upregulate Pif1. Genetic loss of Pif1 in primary tumor cells increases genomic instability and fork stalling when G4s are stabilized, implicating PIF1 as a tumor maintenance factor and potential therapeutic target.

Conclusion:
G4 DNA structures are an endogenous source of replication stress in proliferating GCPs that, without BRCA2, lead to genome instability and medulloblastoma; tumor cells compensate by upregulating PIF1, which may be exploitable therapeutically.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
G-quadruplexes as a source of vulnerability in BRCA2-deficient granule cell progenitors and medulloblastoma

First author:
Keahia DL

Journal:
Proceedings of the National Academy of Sciences (PNAS)

DOI:
10.1073/pnas.2503872122

Reference:
Keahia DL, Sanders MA, Paul MR, Webster ALH, Hatten ME, Smogorzewska A, et al. G-quadruplexes as a source of vulnerability in BRCA2-deficient granule cell progenitors and medulloblastoma. PNAS. 2025;122(35):e2503872122. doi:10.1073/pnas.2503872122

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/g-quadruplexes-as-a-source-of-vulnerability-in-brca2-deficient-granule-cell-progenitors-and-medulloblastoma

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-08-29.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the central experimental results and claims described in the transcript that map to the article's main findings: BRCA2 deficiency in granule cell progenitors, G4-related replication stress, PIF1 upregulation, Ptch1 overlap with G4s, PDS experiments, and therapeutic implications of PIF1 inhibition.
- transcript topics: BRCA2 function in granule cell progenitors; G-quadruplex structures and replication stress; Brca2Δex3-4; Trp53−/− mouse medulloblastoma model; Structural variant breakpoints and Ptch1 overlap with G4s; PIF1 upregulation and dependency in BRCA2-deficient MB; Pyridostatin (PDS) stabilization of G4s

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 5
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- BRCA2 deficiency (BRCA2Δex3-4) with TP53 loss leads to SHH-subgroup medulloblastoma with complete penetrance in mice.
- G4 structures cause replication fork stalling in BRCA2-deficient GCPs; BRCA2 promotes fork protection at G4s; stabilizing G4s with pyridostatin (PDS) blocks replication and induces
- Ptch1 mutations in MB overlap with G4-dense loci; SVs/CNVs in MBs co-localize with predicted G4-forming sequences in both mouse and human samples.
- PIF1 helicase is highly upregulated in BRCA2-deficient MBs and supports replication through G4s; PIF1 knockout impairs replication and increases genomic instability, suggesting a t
- Targeting PIF1 could selectively kill BRCA2-deficient MB cells (synthetic lethality) when combined with other therapies; limitations exist (p53 status, incomplete mechanistic detai
- PDS experiments, EdU incorporation, fork speed measurements, and micronuclei formation collectively support a BRCA2-G4-PIF1 axis in MB.

QC result: Pass.

120: When the Clock Breaks: BMAL1 Variants and a Neurodevelopmental Syndrome

Gustavo Barra — Thu, 28 Aug 2025 12:08:21 +0000

Cuddapah VA et al., Proceedings of the National Academy of Sciences (PNAS) - An international series of 10 individuals with ultrarare heterozygous BMAL1 variants present a syndromic neurodevelopmental phenotype (developmental delay, autism, variable sleep issues, seizures, marfanoid features). Functional assays in human cells and Drosophila show both loss- and gain-of-function effects on BMAL1 activity, PER2 expression, circadian rhythms, and memory, supporting BMAL1 disruption as a cause of neurodevelopmental disease. Key terms: BMAL1, neurodevelopmental disorder, circadian rhythms, developmental delay, Drosophila.

Study Highlights:
Through gene-matching the authors identified 10 individuals carrying ultrarare BMAL1 variants, many de novo, sharing developmental delay and autism spectrum disorder. CRISPR-edited U2OS Per2-dLuc reporter lines showed 8/9 tested variants altered PER2 transcription and circadian parameters, indicating loss- or gain-of-function effects. Two conserved variants modeled in Drosophila produced variant-dependent changes in locomotor rhythms and impaired short- and long-term memory. Together the cellular and in vivo data support pathogenicity of BMAL1 variants in a neurodevelopmental syndrome.

Conclusion:
Ultrarare heterozygous BMAL1 variants can disrupt molecular clock function and contribute to a syndromic neurodevelopmental disorder; these results motivate further study of circadian-targeted assessment and interventions in affected individuals.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Rare variants in BMAL1 are associated with a neurodevelopmental syndrome

First author:
Cuddapah VA

Journal:
Proceedings of the National Academy of Sciences (PNAS)

DOI:
10.1073/pnas.2427085122

Reference:
Cuddapah VA, Chen D, Cho B, et al. Rare variants in BMAL1 are associated with a neurodevelopmental syndrome. Proc Natl Acad Sci U S A. 2025;122(31):e2427085122. doi:10.1073/pnas.2427085122

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/rare-bmal1-variants-link-the-circadian-clock-to-neurodevelopment

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-08-28.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Substantive auditing of sections describing BMAL1 clock mechanism, patient cohort and variants, cell-based PER2-dLuc assays, BMAL1 expression and CLOCK interaction, Drosophila cycle model and memory outcomes, and the clinical sleep phenotype discussion.
- transcript topics: BMAL1 clock mechanism overview; GeneMatcher cohort (10 individuals) and ultrarare BMAL1 variants; CRISPR-edited U2OS Per2-dLuc cell assays; BMAL1 expression and CLOCK interaction; Drosophila cycle ortholog modeling; Memory assays in flies (short-term and long-term)

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- Ten individuals with ultrarare BMAL1 variants identified in the cohort.
- Eight of nine tested BMAL1 variants disrupted BMAL1 function in cell-based assays.
- BMAL1 Ile201Thr variant showed gain-of-function, increasing signal magnitude and advancing rhythm.
- Drosophila ortholog cycle variants exhibited variant-dependent effects on behavioral rhythms.
- Memory impairment observed in flies expressing variant cycle (short-term and long-term).
- Clinical phenotype includes developmental delay and autism; seizures present in a subset; marfanoid habitus observed in subset.

QC result: Pass.

119: G-quadruplexes, pericentromeres, and B cell genome instability

Gustavo Barra — Wed, 27 Aug 2025 08:30:48 +0000

Waisertreiger I et al., PNAS - This study tests how stabilization of G-quadruplex (G4) DNA by ligands such as pyridostatin (PDS) affects genome stability in primary and malignant B cells. The authors map PDS-induced chromosomal breaks and fusions to ribosomal DNA (rDNA) and pericentromeric major satellite (MaSat) repeats and link G4 stabilization to tetraploidization in cells lacking G2/M arrest. Key terms: G-quadruplex, pyridostatin, pericentromeric, ribosomal DNA, tetraploidy.

Study Highlights:
Pyridostatin (PDS) treatment induces recurrent DNA breaks and chromosome fusions localized mainly to rDNA arrays and pericentromeric MaSat repeats in mouse primary B cells and B cell lymphoma lines. PDS causes high levels of tetraploid metaphases in primary mouse B cells (and in GM12878 cells) that correlate with abundant dicentric chromosomes and absence of a WEE1-dependent G2/M arrest, whereas CH12 cells arrest in G2/M and largely avoid tetraploid metaphases. Similar pericentromeric fragility is seen with the G4 ligand CX-5461 and in human lymphoma cell lines, supporting a role for G4 stabilization in driving pericentromeric instability.

Conclusion:
G4-stabilizing ligands provoke replication-associated breaks at rDNA and pericentromeric repeats, producing dicentric fusions and, when checkpoint arrest is absent, tetraploidization; this identifies both a vulnerability in B cell cancers and a potential therapeutic avenue with caution for off-target tetraploidization.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
G- quadruplex stabilization induces DNA breaks in pericentromeric repetitive DNA sequences in B lymphocytes

First author:
Waisertreiger I

Journal:
PNAS

DOI:
10.1073/pnas.2506939122

Reference:
Waisertreiger I., Ayelea K., Elshaikha M.H., Barlow J.H. PNAS (2025) doi:10.1073/pnas.2506939122

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00

Official website https://basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/gquadruplex-stabilization-triggers-pericentromeric-dna-breaks-in-b-cells

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-08-27.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Substantive audit of mechanistic and experimental results: G4 stabilization by PDS, localization of breaks to rDNA and pericentromeric MaSat repeats, tetraploidy in mouse primary B cells and GM12878, absence of tetraploidy in CH12 due to G2/M arrest (and its reversal by inhibitors), human B cell lines (GM12878 and Raji
- transcript topics: G-quadruplex structures and PDS mechanism; PDS-induced chromosomal breaks at rDNA and MaSat repeats; tetraploidy and cell-cycle checkpoint differences across cell types; CH12 cells: G2/M arrest, CDK1 inhibition, WEE1 interplay; human B cell lines GM12878 and Raji; PBMC safety; therapeutic implications, drug combinations, and safety considerations

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 5
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- PDS stabilizes G-quadruplexes and locks them, hindering helicase unwinding and triggering replication-associated DNA breaks
- PDS-induced damage localizes predominantly to rDNA repeats and pericentromeric MaSat repeats in mouse primary B cells
- Tetraploidy is observed in mouse primary B cells and in GM12878 human B cells after PDS treatment; CH12 cells display G2/M arrest preventing tetraploidy
- Healthy PBMCs show little to no chromosomal instability under PDS exposure, indicating a therapeutic window
- CX-5461 and Phen-DC3 also drive pericentromeric damage, supporting a G4-stabilization mechanism; WEE1 inhibition can modulate G2/M arrest and tetraploidy
- Combination strategies (e.g., PDS with WEE1 inhibitors) enhance chromosomal instability in CH12 cells, suggesting potential synergy

QC result: Pass.