Long-term experimental hybridisation results in the evolution of a new sex chromosome in swordtail fish

• DOI: 10.1038/s41467-018-07648-2
• Publication Date: 2018-11-27T15:44:20Z
• Authors: Paolo Franchini; Julia C. Jones; Peiwen Xiong; Susanne Kneitz; Zachariah Gompert; Wesley C. Warren; Ronald B. Walter; Axel Meyer; Manfred Schartl
• Keywords: Xiphophorus; Introgression

The remarkable diversity of sex determination mechanisms known in fish may be fuelled by exceptionally high rates chromosome turnovers or transitions. However, the evolutionary causes and genomic underlying this variation instability are yet to understood. Here we report on an over 30-year experiment which tested consequences hybridisation selection between two Xiphophorus species with different systems. We find that introgression imposing for pigmentation phenotypes results retention unexpectedly large maternally derived region. During process, sex-determining region X from one parental was translocated autosome hybrids leading evolution a new chromosome. Our highlight complexity factors contributing patterns observed hybrid genomes, experimentally demonstrate can catalyze rapid