New insights into Xenopus sex chromosome genomics from the Marsabit clawed frog X. borealis.

Autor: Evans BJ; Biology Department, Life Sciences Building Room 328, McMaster University, Hamilton, Ontario, Canada., Mudd AB; Department of Molecular and Cell Biology, University of California, Berkeley, California, USA., Bredeson JV; Department of Molecular and Cell Biology, University of California, Berkeley, California, USA., Furman BLS; Biology Department, Life Sciences Building Room 328, McMaster University, Hamilton, Ontario, Canada.; Canexia Health, Vancouver, British Columbia, Canada., Wasonga DV; National Museums of Kenya, Nairobi, Kenya., Lyons JB; Department of Molecular and Cell Biology, University of California, Berkeley, California, USA., Harland RM; Department of Molecular and Cell Biology, University of California, Berkeley, California, USA., Rokhsar DS; Department of Molecular and Cell Biology, University of California, Berkeley, California, USA.; Okinawa Institute of Science and Technology Graduate University, Onna, Japan.; Chan-Zuckerberg BioHub, San Francisco, California, USA.
Jazyk: angličtina
Zdroj: Journal of evolutionary biology [J Evol Biol] 2022 Dec; Vol. 35 (12), pp. 1777-1790. Date of Electronic Publication: 2022 Aug 24.
DOI: 10.1111/jeb.14078
Abstrakt: In many groups, sex chromosomes change frequently but the drivers of their rapid evolution are varied and often poorly characterized. With an aim of further understanding sex chromosome turnover, we investigated the polymorphic sex chromosomes of the Marsabit clawed frog, Xenopus borealis, using genomic data and a new chromosome-scale genome assembly. We confirmed previous findings that 54.1 Mb of chromosome 8L is sex-linked in animals from east Kenya and a laboratory strain, but most (or all) of this region is not sex-linked in natural populations from west Kenya. Previous work suggests possible degeneration of the Z chromosomes in the east population because many sex-linked transcripts of this female heterogametic population have female-biased expression, and we therefore expected this chromosome to not be present in the west population. In contrast, our simulations support a model where most or all of the sex-linked portion of the Z chromosome from the east acquired autosomal segregation in the west, and where much genetic variation specific to the large sex-linked portion of the W chromosome from the east is not present in the west. These recent changes are consistent with the hot-potato model, wherein sex chromosome turnover is favoured by natural selection if it purges a (minimally) degenerate sex-specific sex chromosome, but counterintuitively suggest natural selection failed to purge a Z chromosome that has signs of more advanced and possibly more ancient regulatory degeneration. These findings highlight complex evolutionary dynamics of young, rapidly evolving Xenopus sex chromosomes and set the stage for mechanistic work aimed at pinpointing additional sex-determining genes in this group.
(© 2022 European Society for Evolutionary Biology.)
Databáze: MEDLINE
Externí odkaz: