{
  "id": 9557584,
  "title": "Maintenance of quantitative genetic variation in regions of restricted recombination via associative overdominance",
  "url": "https://urgent.news/2026/09/24/maintenance-of-quantitative-genetic-variation-in-regions-of",
  "topic": "science",
  "section": "Science",
  "published": "2026-09-24T00:00:00.000Z",
  "source": {
    "name": "bioRxiv",
    "slug": "biorxiv",
    "url": "https://www.biorxiv.org/content/10.64898/2026.09.20.752755v1?rss=1"
  },
  "original_language": "en",
  "account": "Mutation-selection balance is considered the primary mechanism for preserving additive genetic variance in quantitative traits among natural populations. It is widely recognized that genetic variants influencing traits (QTLs) are scattered throughout species genomes. Nevertheless, deleterious mutations that have a significant impact on fitness are typically recessive. Genomes often contain regions with limited recombination, which can result in close linkage between numerous recessive deleterious alleles. This situation can generate elevated heterozygosity through associative overdominance.\n\nThe study reveals that weakly selected QTLs connected to genomic areas displaying AOD can augment VA beyond the expected levels without the presence of unconditionally deleterious mutations. However, when traits are subject to selection under these conditions, recessive deleterious alleles may be exposed as homozygotes, leading to a decline in fitness. Consequently, although AOD can aid in preserving VA, the genetic variation maintained through this mechanism might not be readily accessible through either natural or artificial selection.",
  "summary": "Mutation-selection balance is the most plausible general mechanism for the maintenance of additive genetic variance (VA) for quantitative traits in natural populations. It is well established that the genetic variants affecting traits (QTLs) are widely distributed across species' genomes. At the same time, unconditionally deleterious mutations are also expected to be common, with those with the…",
  "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."
}