A gradual process of recombination restriction in the evolutionary history of the sex chromosomes in dioecious plants.

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Serval ID
serval:BIB_EB5E0C827FCC
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
A gradual process of recombination restriction in the evolutionary history of the sex chromosomes in dioecious plants.
Journal
PLoS Biology
Author(s)
Nicolas M., Marais G., Hykelova V., Janousek B., Laporte V., Vyskot B., Mouchiroud D., Negrutiu I., Charlesworth D., Monéger F.
ISSN
1545-7885
Publication state
Published
Issued date
2005
Peer-reviewed
Oui
Volume
3
Number
1
Pages
e4
Language
english
Notes
Publication types: Journal Article ; Research Support, Non-U.S. Gov't
Abstract
To help understand the evolution of suppressed recombination between sex chromosomes, and its consequences for evolution of the sequences of Y-linked genes, we have studied four X-Y gene pairs, including one gene not previously characterized, in plants in a group of closely related dioecious species of Silene which have an X-Y sex-determining system (S. latifolia, S. dioica, and S. diclinis). We used the X-linked copies to build a genetic map of the X chromosomes, with a marker in the pseudoautosomal region (PAR) to orient the map. The map covers a large part of the X chromosomes--at least 50 centimorgans. Except for a recent rearrangement in S. dioica, the gene order is the same in the X chromosomes of all three species. Silent site divergence between the DNA sequences of the X and Y copies of the different genes increases with the genes' distances from the PAR, suggesting progressive restriction of recombination between the X and Y chromosomes. This was confirmed by phylogenetic analyses of the four genes, which also revealed that the least-diverged X-Y pair could have ceased recombining independently in the dioecious species after their split. Analysis of amino acid replacements vs. synonymous changes showed that, with one possible exception, the Y-linked copies appear to be functional in all three species, but there are nevertheless some signs of degenerative processes affecting the genes that have been Y-linked for the longest times. Although the X-Y system evolved quite recently in Silene (less than 10 million years ago) compared to mammals (about 320 million years ago), our results suggest that similar processes have been at work in the evolution of sex chromosomes in plants and mammals, and shed some light on the molecular mechanisms suppressing recombination between X and Y chromosomes.
Keywords
Animals, Chromosome Mapping, Chromosomes, Plant, DNA, Complementary, Evolution, Molecular, Genetic Variation, Linkage (Genetics), Molecular Sequence Data, Phylogeny, Polymorphism, Genetic, Sequence Analysis, DNA, Sex Chromosomes, Silene, X Chromosome, Y Chromosome
Pubmed
Web of science
Open Access
Yes
Create date
19/11/2007 10:53
Last modification date
20/08/2019 16:13
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