Base by Base

Gustavo Barra
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Base by Base explores advances in genetics and genomics, with a focus on gene-disease associations, variant interpretation, protein structure, and insights from exome and genome sequencing. Each episode breaks down key studies and their clinical relevance—one base at a time. Powered by AI, Base by Base offers a new way to learn on the go. Special thanks to authors who publish under CC BY 4.0, making open-access science faster to share and easier to explore.

  1. 20 HR AGO

    308: PANDORA-seq reveals conserved rsRNA length shift and tsRNA/rsRNA aging cliff in mouse and human sperm

    Shi J et al., The EMBO Journal - 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. 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. 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

    22 min

  2. 1 DAY AGO

    307: SNIPE membrane nuclease cleaves phage λ DNA during ManYZ-mediated genome injection in Escherichia coli

    Saxton DS et al., Nature - 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. 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. 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

    28 min

  3. 2 DAYS AGO

    306: SAXO6 loss-of-function in photoreceptor cilia links a microtubule inner protein to late-onset retinal dystrophy

    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. 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. 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

    25 min

  4. 3 DAYS AGO

    305: Human cis-regulatory variants dissected by MPRA at single-nucleotide resolution

    Siraj L et al., Nature - 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. 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. 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

    22 min

  5. 3 DAYS AGO

    304: Patrilineal Y‑chromosome drive in a Utah pedigree (67% male offspring)

    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. 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. 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

    18 min

  6. 5 DAYS AGO

    303: Short-read sequencing and genome skimming for biodiversity monitoring and phylogenomics

    Bleidorn C et al., Trends Genet - 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. 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. 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 Chapters (00:00:20) - Base by Bass(00:02:08) - The untapped potential of short-read sequencing in biodiversity science(00:09:38) - Genome Skimming to accurately estimate the biomass of marine organisms(00:16:23) - The race for low-cost sequencing(00:24:16) - Short-read sequencing: The secrets of the last ice age

    29 min

  7. 6 DAYS AGO · BONUS

    302 auf Deutsch: SMN1/SMN2-Spleißen und Mechanismen im letzten Exon — Hommage an Brunhilde Wirth

    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/

    14 min

  8. 26 FEB

    302: SMN1/SMN2 splicing and last-exon mechanisms — Tribute to Brunhilde Wirth

    A Tribute Dossier Celebrating the Scientific Career of Prof. Brunhilde Wirth highlighting SMN1/SMN2 alternative splicing studies using molecular genetics and functional assays that clarified variant effects in SMA. Study Highlights: This dossier reviews decades of work in human genetics and spinal muscular atrophy, emphasizing studies of SMN1 and SMN2. Key methods included molecular genetics, splicing analysis, protein expression measurements, and stability assays to validate variant effects. A central mechanistic finding is that late coding-sequence disruptions can behave differently than simple models predict, with some transcripts escaping expected nonsense-mediated decay and altering protein stability. These experimentally validated insights have direct implications for diagnostic interpretation, newborn screening, and genotype–phenotype correlation in SMA. Conclusion: Prof. Wirth's career demonstrates that experimental validation of splicing and protein-stability effects of SMN1/SMN2 variants is essential for accurate clinical interpretation in SMA. Music: Enjoy the music based on this article at the end of the episode. 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 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

    24 min
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About

Base by Base explores advances in genetics and genomics, with a focus on gene-disease associations, variant interpretation, protein structure, and insights from exome and genome sequencing. Each episode breaks down key studies and their clinical relevance—one base at a time. Powered by AI, Base by Base offers a new way to learn on the go. Special thanks to authors who publish under CC BY 4.0, making open-access science faster to share and easier to explore.

Information

  • Creator
    Gustavo Barra
  • Years Active
    2025 - 2026
  • Episodes
    310
  • Rating
    Clean
  • Copyright
    © Gustavo Barra
  • Show Website
    Base by Base