{
  "id": 14984294,
  "title": "Genome-wide chromatin reset at the onset of leg regeneration in pancrustaceans",
  "url": "https://urgent.news/2026/10/16/genome-wide-chromatin-reset-at-the-onset-of-leg-regeneration-in",
  "topic": "science",
  "section": "Science",
  "published": "2026-10-16T00:00:00.000Z",
  "source": {
    "name": "bioRxiv",
    "slug": "biorxiv",
    "url": "https://www.biorxiv.org/content/10.64898/2026.10.09.757970v1?rss=1"
  },
  "original_language": "en",
  "account": "The ability of organisms to regenerate damaged limbs hinges on the careful reactivation of specific developmental pathways. However, the precise chromatin changes underlying this process are not well understood. Researchers investigated this in two pancrustacean models: the two-spotted cricket Gryllus bimaculatus and the crustacean Parhyale hawaiensis. Both species display a progressive decline in limb regeneration during nymphal development, with adults exhibiting no regenerative capacity.\n\nTo gain insights into this process, the researchers established genomic and epigenomic frameworks for each species. Following limb amputation, they observed a comprehensive genome-wide shutdown of enhancer-associated chromatin. This involved a loss of accessible regulatory regions and a depletion of H3K27ac and H3K4me1 marks. Following this broad chromatin shutdown, regeneration-competent tissue exhibited a selective reopening of a restricted subset of regulatory elements, along with the strong activation of the pioneer transcription factor Zelda (GbZelda in crickets).\n\nInterestingly, the GbZelda locus was uniquely characterized by the presence of both H3K27me3 and H3K9me3 in intact leg tissue. After injury, H3K9me3 levels were broadly reduced, while H3K27me3 was selectively relieved in regenerating nymphs. Parhyale hawaiensis followed a similar chromatin narrative during appendage regeneration - an initial enhancer shutdown followed by selective reopening of regulatory regions, coinciding with the upregulation of Zelda.\n\nIn summary, the studies revealed that pancrustacean appendage regeneration shares a conserved sequence of events: a genome-wide chromatin reset, selective reopening of regulatory elements, and activation of the pioneer transcription factor Zelda. This conserved mechanism contrasts with the wholesale restoration of the pre-injury regulatory landscape.",
  "summary": "Regeneration requires injured tissues to selectively reactivate certain developmental programs while triggering regeneration-specific mechanisms and responding to the immediate consequences of tissue damage. How chromatin states are reorganized during this transition, and whether the underlying sequence of regulatory events is conserved across regenerating animals, remain poorly understood. We…",
  "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."
}