Biased Gene Conversion and GC-Content Evolution in the Coding Sequences of Reptiles and Vertebrates - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Genome Biology and Evolution Année : 2015

Biased Gene Conversion and GC-Content Evolution in the Coding Sequences of Reptiles and Vertebrates

Résumé

Mammalian and avian genomes are characterized by a substantial spatial heterogeneity of GC-content, which is often interpreted as reflecting the effect of local GC-biased gene conversion (gBGC), a meiotic repair bias that favors G and C over A and T alleles in high-recombining genomic regions. Surprisingly, the first fully sequenced nonavian sauropsid (i.e., reptile), the green anole Anolis carolinensis, revealed a highly homogeneous genomic GC-content landscape, suggesting the possibility that gBGC might not be at work in this lineage. Here, we analyze GC-content evolution at third-codon positions (GC3) in 44 vertebrates species, including eight newly sequenced transcriptomes, with a specific focus on nonavian sauropsids. We report that reptiles, including the green anole, have a genome-wide distribution of GC3 similar to that of mammals and birds, and we infer a strong GC3-heterogeneity to be already present in the tetrapod ancestor. We further show that the dynamic of coding sequence GC-content is largely governed by karyotypic features in vertebrates, notably in the green anole, in agreement with the gBGC hypothesis. The discrepancy between third-codon positions and noncoding DNA regarding GC-content dynamics in the green anole could not be explained by the activity of transposable elements or selection on codon usage. This analysis highlights the unique value of third-codon positions as an insertion/deletion-free marker of nucleotide substitution biases that ultimately affect the evolution of proteins.
Fichier principal
Vignette du fichier
Figuet2014.pdf (532.87 Ko) Télécharger le fichier
Origine : Fichiers éditeurs autorisés sur une archive ouverte
Loading...

Dates et versions

hal-01900679 , version 1 (22-10-2018)

Identifiants

Citer

Emeric Figuet, Marion Ballenghien, Jonathan Romiguier, Nicolas Galtier. Biased Gene Conversion and GC-Content Evolution in the Coding Sequences of Reptiles and Vertebrates. Genome Biology and Evolution, 2015, 7 (1), pp.240-250. ⟨10.1093/gbe/evu277⟩. ⟨hal-01900679⟩
116 Consultations
80 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More