Skip to Main content Skip to Navigation
Preprints, Working Papers, ...

A deleterious mutation-sheltering theory for the evolution of sex chromosomes and supergenes

Abstract : Many organisms have sex chromosomes with large non-recombining regions having expanded stepwise, the reason why being still poorly understood. Theories proposed so far rely on differences between sexes but are poorly supported by empirical data and cannot account for the stepwise suppression of recombination around sex-determining loci in organisms without sexual dimorphism. We show here, by mathematical modeling and stochastic simulations, that recombination suppression in sex chromosomes can evolve simply because it shelters recessive deleterious mutations, which are ubiquitous in genomes. The permanent heterozygosity of sex-determining alleles protects linked chromosomal inversions against expression of their recessive mutation load, leading to an accumulation of inversions around these loci, as observed in nature. We provide here a testable and widely applicable theory to explain the evolution of sex chromosomes and of supergenes in general.
Document type :
Preprints, Working Papers, ...
Complete list of metadata

https://hal.archives-ouvertes.fr/hal-03365741
Contributor : Tatiana Giraud Connect in order to contact the contributor
Submitted on : Tuesday, October 5, 2021 - 1:23:34 PM
Last modification on : Friday, October 8, 2021 - 3:37:13 AM

File

Jay A deleterious mutation-she...
Files produced by the author(s)

Identifiers

Citation

Paul Jay, Emilie Tezenas, Tatiana Giraud. A deleterious mutation-sheltering theory for the evolution of sex chromosomes and supergenes. 2021. ⟨hal-03365741⟩

Share

Metrics

Record views

21

Files downloads

15