The rise and fall of the ancient northern pike master sex-determining gene

Elife. 2021 Jan 28:10:e62858. doi: 10.7554/eLife.62858.

Abstract

The understanding of the evolution of variable sex determination mechanisms across taxa requires comparative studies among closely related species. Following the fate of a known master sex-determining gene, we traced the evolution of sex determination in an entire teleost order (Esociformes). We discovered that the northern pike (Esox lucius) master sex-determining gene originated from a 65 to 90 million-year-old gene duplication event and that it remained sex linked on undifferentiated sex chromosomes for at least 56 million years in multiple species. We identified several independent species- or population-specific sex determination transitions, including a recent loss of a Y chromosome. These findings highlight the diversity of evolutionary fates of master sex-determining genes and the importance of population demographic history in sex determination studies. We hypothesize that occasional sex reversals and genetic bottlenecks provide a non-adaptive explanation for sex determination transitions.

Keywords: esocidae; esociforms; evolutionary biology; fish; master sex determining gene; mudminnows; pikes; sex determination; umbridae.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Esocidae / genetics*
  • Female
  • Gene Duplication*
  • Male
  • Phylogeny
  • Sex Chromosomes / genetics*
  • Sex Determination Processes / physiology*