Accumulation of slightly deleterious mutations in mitochondrial protein-coding genes of large versus small mammals.

ABSTRACT: After the effective size of a population, N(e), declines, some slightly deleterious amino acid replacements which were initially suppressed by purifying selection become effectively neutral and can reach fixation. Here we investigate this phenomenon for a set of all 13 mitochondrial protein-coding genes from 110 mammalian species. By using body mass as a proxy for N(e), we show that large mammals (i.e., those with low N(e)) as compared with small ones (in our sample these are, on average, 369.5 kg and 275 g, respectively) have a 43% higher rate of accumulation of nonsynonymous nucleotide substitutions relative to synonymous substitutions, and an 8-40% higher rate of accumulation of radical amino acid substitutions relative to conservative substitutions, depending on the type of amino acid

SUBMITTER: Popadin K 

PROVIDER: S-EPMC1948928 | biostudies-literature | 2007 Aug

REPOSITORIES: biostudies-literature