{
  "abstract": "How do sex chromosomes evolve in the transition to asexuality? So far, species that depart from canonical sexual reproduction-for example, parthenogens with rare sex or species where the paternal genome is set aside-have been found to carry either no sex chromosomes or sex chromosomes but no male-specific sex chromosome (i.e. no Y). Here we reveal that, in Mesorhabditis nematodes, a new Y chromosome evolved once, from sexual ancestors, in species that have transitioned into an unconventional mode of reproduction called autopseudogamy. In this reproductive system, females produce clonal females plus rare (∼10%) males that are needed for fertilization but that do not contribute to the female genome. Analyzing the Y chromosomes of two autopseudogamous species, we found high levels of degeneration, most likely due to loss of recombination, and two additional conserved features: (i) they accumulated male-beneficial genes, and (ii) they display a strong fertilization drive, in that mainly Y-bearing sperm fertilize female oocytes. Both features are likely evolutionarily favorable in the context of autopseudogamy. Our results suggest that male-specific chromosomes can still be maintained in systems with rare, and possibly \"genetically useless,\" males.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": null,
  "author_total": 9,
  "authors": [
    {
      "name": "Brice Letcher"
    },
    {
      "name": "Lewis Stevens"
    },
    {
      "name": "Nathanaëlle Saclier"
    },
    {
      "name": "Andrew Hsiao"
    },
    {
      "name": "Manuela Kieninger"
    },
    {
      "name": "Eva Wenger"
    },
    {
      "name": "Caroline Launay"
    },
    {
      "name": "Mark Blaxter"
    },
    {
      "name": "Marie Delattre"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/1vara44pwagpt.bib",
  "cited_by": 0,
  "doi": "10.1093/molbev/msag177",
  "fulltext_url": null,
  "id": "1vara44pwagpt",
  "issns": [
    "0737-4038",
    "1537-1719"
  ],
  "landing_url": "https://hal.science/hal-05848535v1",
  "language": "en",
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "journal",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "hal",
      "0.sdv"
    ],
    [
      "openalex",
      "1311|Genetic and Clinical Aspects of Sex Determination and Chromosomal Abnormalities"
    ]
  ],
  "openalex": "W4413097777",
  "pdf_url": null,
  "pmcid": null,
  "pmid": null,
  "published": "2026-08-01",
  "publisher": "Oxford University Press (OUP)",
  "ris": "https://research.draconitic.com/paper/1vara44pwagpt.ris",
  "sources": [
    {
      "first_seen": "2026-11-03T12:20:17Z",
      "native_id": "hal-05848535",
      "source": "hal",
      "url": "https://hal.science/hal-05848535v1"
    }
  ],
  "subjects": [
    {
      "field": "biology",
      "origin": "openalex:1311|Genetic and Clinical Aspects of Sex Determination and Chromosomal Abnormalities",
      "subfield": "genetics-genomics"
    }
  ],
  "title": "Emergence and stabilization of a neo-Y chromosome in nematode species with rare males",
  "title_text": "Emergence and stabilization of a neo-Y chromosome in nematode species with rare males",
  "type": "peer-reviewed",
  "updated_at": "2026-11-04T12:20:48Z",
  "url": "https://research.draconitic.com/paper/1vara44pwagpt",
  "venue": "Molecular Biology and Evolution",
  "versions": []
}