Eyre-Walker Adam
Centre for the Study of Evolution, University of Sussex, Brighton BN1 9QG, United Kingdom.
Genetics. 2002 Dec;162(4):2017-24. doi: 10.1093/genetics/162.4.2017.
Artifactual evidence of adaptive amino acid substitution can be generated within a McDonald-Kreitman test if some amino acid mutations are slightly deleterious and there has been an increase in effective population size. Here I investigate the conditions under which this occurs. I show that fairly small increases in effective population size can generate artifactual evidence of positive selection if there is no selection upon synonymous codon use. This problem is exacerbated by the removal of low-frequency polymorphisms. However, selection on synonymous codon use restricts the conditions under which artifactual evidence of adaptive evolution is produced.
如果某些氨基酸突变略有有害性且有效种群大小增加,那么在麦克唐纳 - 克赖特曼检验中可能会产生适应性氨基酸替代的人为证据。在此,我研究了发生这种情况的条件。我表明,如果对同义密码子的使用没有选择,有效种群大小相当小的增加就可能产生正选择的人为证据。去除低频多态性会加剧这个问题。然而,对同义密码子使用的选择限制了产生适应性进化人为证据的条件。