{
  "id": 14232698,
  "title": "Cross-species analysis identifies APOBEC3-associated spliceosomal snRNA hypermutability",
  "url": "https://urgent.news/2026/10/13/cross-species-analysis-identifies-apobec3-associated-spliceosomal",
  "topic": "science",
  "section": "Science",
  "published": "2026-10-13T00:00:00.000Z",
  "source": {
    "name": "bioRxiv",
    "slug": "biorxiv",
    "url": "https://www.biorxiv.org/content/10.64898/2026.10.12.758683v1?rss=1"
  },
  "original_language": "en",
  "account": "Spliceosomal small nuclear RNA (snRNA) genes exhibit higher mutation rates in germline cells, with R-loop formation previously thought to contribute to this hypermutability. By examining rare-variant and de novo mutations across species, researchers found that this hypermutability is primarily concentrated in RNA polymerase II-transcribed spliceosomal snRNA genes. Notably, this pattern shows a strong enrichment in primates, while rodents and chicken display a much weaker excess, suggesting lineage-specific differences in APOBEC3 repertoires. Human Pol II-transcribed spliceosomal snRNA genes exhibit a strand asymmetry in mutations, as well as APOBEC3-associated mutational signatures and strong signals for APOBEC3B binding. Additionally, R-loops are frequently observed at these loci, even in mouse genes with considerably less hypermutability, implying that R-loop formation alone is not enough to account for the hypermutability observed in these genes. Overall, comparing data across species supports the idea that lineage-specific APOBEC3 activity plays a significant role in spliceosomal snRNA gene hypermutability, rather than R-loop formation being the sole cause.",
  "summary": "Spliceosomal small nuclear RNA (snRNA) genes show unusually high germline mutation rates, with R-loop formation previously implicated in this mutability. Our cross-species rare-variant and de novo mutation analyses show that hypermutability is concentrated in RNA polymerase II-transcribed spliceosomal snRNA genes, with strong enrichment in primates but a much weaker excess in rodents and chicken,…",
  "key_points": [],
  "editors_take": null,
  "illustration": null,
  "coverage": {
    "outlets": 1,
    "also_reported_by": []
  },
  "ai_generated": true,
  "disclaimer": "Summaries, key points and the editor’s take are written by software from other outlets’ reporting and may contain errors — always check the linked original."
}