Impact of changes in GC content on the silent molecular clock in murids.

Détails

ID Serval
serval:BIB_11E5C314FB70
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Impact of changes in GC content on the silent molecular clock in murids.
Périodique
Gene
Auteur(s)
Mouchiroud D., Robinson M., Gautier C.
ISSN
0378-1119 (Print)
ISSN-L
0378-1119
Statut éditorial
Publié
Date de publication
1997
Volume
205
Numéro
1-2
Pages
317-322
Langue
anglais
Résumé
Murid nuclear genomes are more homogeneous in GC content than those of most mammals, which leads to the question of how such important compositional changes have accumulated. This paper reports on relationships between frequencies of synonymous differences and GC change, in the lineages leading to human and murids. For this, we used the four-species approach: GC changes between human and murids were compared to the frequencies of synonymous differences, measured between two independent species without GC change (bovine and pig), by using orthologous genes common to all four species. We report three conclusions: (1) Among genes with little GC change, 60% of the variability of synonymous substitution frequencies is explained by the gene-specific rate component. (2) GC changes in murid genomes are independent of the gene-specific rate component. Slowly evolving genes in pig bovine comparison can show strong GC change in murids. (3) By using a GC-independent estimate of the substitution rate, we show that GC changes in murid genomes increase synonymous substitution frequencies. The GC homogenization considerably weakens the gene-specific conservation of substitution rates in murids, and could explain part of the increase of evolutionary rates observed in this group. We present a mechanism that can account for the evolution of the GC homogenization in murids.
Mots-clé
Animals, Cattle, Cytosine/analysis, Evolution, Molecular, Genome, Guanine/analysis, Humans, Muridae/genetics, Muridae/physiology
Pubmed
Web of science
Création de la notice
24/01/2008 18:47
Dernière modification de la notice
20/08/2019 13:39
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