Expanding the classical paradigm: what we have learnt from vertebrates about sex chromosome evolution

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Ressource 1Download: Kratochvil et al. 2021 Phil Trans B.pdf (577.31 [Ko])
State: Public
Version: Final published version
License: CC BY 4.0
Serval ID
serval:BIB_DEC9024906B8
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Expanding the classical paradigm: what we have learnt from vertebrates about sex chromosome evolution
Journal
Philosophical Transactions of the Royal Society B: Biological Sciences
Author(s)
Kratochvíl Lukáš, Stöck Matthias, Rovatsos Michail, Bullejos Mónica, Herpin Amaury, Jeffries Daniel L., Peichel Catherine L., Perrin Nicolas, Valenzuela Nicole, Pokorná Martina Johnson
ISSN
0962-8436
1471-2970
Publication state
Published
Issued date
13/09/2021
Volume
376
Number
1833
Pages
20200097
Language
english
Abstract
Until recently, the field of sex chromosome evolution has been dominated by the canonical unidirectional scenario, first developed by Muller in 1918. This model postulates that sex chromosomes emerge from autosomes by acquiring a sex-determining locus. Recombination reduction then expands outwards from this locus, to maintain its linkage with sexually antagonistic/ advantageous alleles, resulting in Y or W degeneration and potentially culmi- nating in their disappearance. Based mostly on empirical vertebrate research, we challenge and expand each conceptual step of this canonical model and present observations by numerous experts in two parts of a theme issue of Phil. Trans. R. Soc. B. We suggest that greater theoretical and empirical insights into the events at the origins of sex-determining genes (rewiring of the gona- dal differentiation networks), and a better understanding of the evolutionary forces responsible for recombination suppression are required. Among others, crucial questions are: Why do sex chromosome differentiation rates and the evolution of gene dose regulatory mechanisms between male versus female heterogametic systems not follow earlier theory? Why do several lineages not have sex chromosomes? And: What are the consequences of the presence of (differentiated) sex chromosomes for individual fitness, evolvability, hybridization and diversification? We conclude that the classical scenario appears too reductionistic. Instead of being unidirectional, we show that sex chromosome evolution is more complex than previously anticipated and principally forms networks, interconnected to potentially endless outcomes with restarts, deletions and additions of new genomic material.
Keywords
evolution, sex chromosomes, sex determination, vertebrates
Open Access
Yes
Create date
27/07/2021 10:06
Last modification date
28/07/2021 7:13
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