The Origin of a New Sex Chromosome by Introgression between Two Stickleback Fishes. (1st October 2018)

• Record Type: Journal Article
• Authors: Dixon, Groves; Kitano, Jun; Kirkpatrick, Mark
• Editors: Sayres, Melissa Wilson
• Is Part Of: Molecular biology and evolution. Volume 36:Number 1(2019)
• Page Start: 28
• Page End: 38
• Publication Date: 2018-10-01
• Subjects: sex chromosome -- introgression -- stickleback -- degeneration -- sex-biased expression; Molecular biology -- Periodicals; Molecular evolution -- Periodicals; Evolution, Molecular -- Periodicals; Molecular Biology -- Periodicals; 572.8
• DOI: 10.1093/molbev/msy181
• Languages: English
• ISSNs: 0737-4038

Abstract

Abstract: Introgression is increasingly recognized as a source of genetic diversity that fuels adaptation. Its role in the evolution of sex chromosomes, however, is not well known. Here, we confirm the hypothesis that the Y chromosome in the ninespine stickleback, Pungitius pungitius, was established by introgression from the Amur stickleback, P. sinensis . Using whole genome resequencing, we identified a large region of Chr 12 in P. pungitius that is diverged between males and females. Within but not outside of this region, several lines of evidence show that the Y chromosome of P. pungitius shares a most recent common ancestor not with the X chromosome, but with the homologous chromosome in P. sinensis . Accumulation of repetitive elements and gene expression changes on the new Y are consistent with a young sex chromosome in early stages of degeneration, but other hallmarks of Y chromosomes have not yet appeared. Our findings indicate that porous species boundaries can trigger rapid sex chromosome evolution.