More radical amino acid replacements in primates than in rodents: support for the evolutionary role of effective population size.

ABSTRACT: We examined the pattern of nucleotide substitution in 4933 conserved single-copy orthologous protein-coding genes of human, rhesus, mouse, and rat. Consistent with previous studies, the median ratio of the number of nonsynonymous substitutions per nonsynonymous site (d(N)) to the number of synonymous substitutions per synonymous site (d(S)) was significantly higher in the comparison between the two primates than in the comparison between the two rodents. This pattern was particularly strong in the case of genes expressed in the immune system, but also occurred in other genes, including a set of highly conserved genes involved in the regulation of transcription. Both synonymous and nonsynonymous differences occurred independently in the same codons in the primates and in the rodents to a gr

SUBMITTER: Hughes AL 

PROVIDER: S-EPMC2706701 | biostudies-literature | 2009 Jul

REPOSITORIES: biostudies-literature