Bulmer M, Wolfe K H, Sharp P M
Department of Statistics, Oxford University, United Kingdom.
Proc Natl Acad Sci U S A. 1991 Jul 15;88(14):5974-8. doi: 10.1073/pnas.88.14.5974.
Synonymous substitution rates have been estimated for 58 genes compared among primates, artiodactyls, and rodents. Although silent sites might be expected to be neutral, there is substantial rate variation among genes within each lineage. Some of the rate variation is associated with G + C content: genes with intermediate G + C values have the highest rates. Nevertheless, considerable heterogeneity remains after correcting for G + C content. Synonymous substitution rates also vary among lineages, but the relative rates of genes are well conserved in different lineages. Certain genes have also been sequenced in a fourth order (lagomorph or carnivore), and these data have been used to investigate mammalian phylogeny. Data on lagomorphs are consistent with a star phylogeny, but there is evidence that carnivores and artiodactyls are sister groups. Genes sequenced in both rat and mouse suggest that the increased substitution rate in rodents has occurred since the rat/mouse divergence.
已估计了灵长类、偶蹄目动物和啮齿动物之间58个基因的同义替换率。虽然沉默位点可能被认为是中性的，但每个谱系内的基因之间存在很大的速率差异。部分速率差异与G + C含量有关：G + C值中等的基因具有最高的速率。然而，校正G + C含量后仍存在相当大的异质性。同义替换率在不同谱系之间也有所不同，但基因的相对速率在不同谱系中保持得很好。某些基因也已在第四个目（兔形目或食肉目）中测序，这些数据已用于研究哺乳动物的系统发育。关于兔形目的数据与星状系统发育一致，但有证据表明食肉动物和偶蹄目动物是姐妹类群。在大鼠和小鼠中都测序的基因表明，啮齿动物的替换率增加是在大鼠/小鼠分化之后发生的。
