Nei M, Gojobori T
Center for Demographic and Population Genetics, University of Texas at Houston 77225.
Mol Biol Evol. 1986 Sep;3(5):418-26. doi: 10.1093/oxfordjournals.molbev.a040410.
Two simple methods for estimating the numbers of synonymous and nonsynonymous nucleotide substitutions are presented. Although they give no weights to different types of codon substitutions, these methods give essentially the same results as those obtained by Miyata and Yasunaga's and by Li et al.'s methods. Computer simulation indicates that estimates of synonymous substitutions obtained by the two methods are quite accurate unless the number of nucleotide substitutions per site is very large. It is shown that all available methods tend to give an underestimate of the number of nonsynonymous substitutions when the number is large.
本文提出了两种估算同义核苷酸替换数和非同义核苷酸替换数的简单方法。尽管这些方法没有对不同类型的密码子替换赋予权重，但它们得出的结果与宫田和安永的方法以及李等人的方法基本相同。计算机模拟表明，除非每个位点的核苷酸替换数非常大，否则用这两种方法获得的同义替换估计值相当准确。结果表明，当非同义替换数很大时，所有现有的方法往往都会低估其数量。
