DNA polymorphism detectable by restriction endonucleases.
DNA polymorphism detectable by restriction endonucleases.
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作者：
M. Nei;F. Tajima
通过限制性核酸内切酶检测到的 DNA 多态性的数据正在迅速积累。为了分析这些数据，提出了几种不同的种群内和种群间核子（DNA 片段）多样性测量方法，并开发了估计这些数量的统计方法。这些统计方法适用于核 DNA 和非核 DNA。当核子的进化变化主要通过突变和遗传漂变发生时，所有的度量都可以用每个核子的突变率和有效种群大小的乘积来表示。还提出了在某些假设下根据核子多样性估计核苷酸多样性的方法。结果表明，两个群体之间的 DNA 差异可以通过限制性位点差异的平均数量或核苷酸差异的平均数量来研究。无论哪种情况，都应该使用大量不同的限制性内切酶来研究相关生物之间的系统发育关系，因为随机因素对这些数量的影响非常大。所开发的统计方法已应用于 Shah 和 Langley 的黑腹果蝇、拟果蝇和绿蝇线粒体 (mt)DNA 数据。该应用表明高等动物线粒体DNA的进化变化主要通过核苷酸取代而不是通过删除和插入发生。还估计了这三个物种之间的进化距离。
Data on DNA polymorphisms detected by restriction endonucleases are rapidly accumulating. With the aim of analyzing these data, several different measures of nucleon (DNA segment) diversity within and between populations are proposed, and statistical methods for estimating these quantities are developed. These statistical methods are applicable to both nuclear and nonnuclear DNAs. When evolutionary change of nucleons occurs mainly by mutation and genetic drift, all the measures can be expressed in terms of the product of mutation rate per nucleon and effective population size. A method for estimating nucleotide diversity from nucleon diversity is also presented under certain assumptions. It is shown that DNA divergence between two populations can be studied either by the average number of restriction site differences or by the average number of nucleotide differences. In either case, a large number of different restriction enzymes should be used for studying phylogenetic relationships among related organisms, since the effect of stochastic factors on these quantities is very large. The statistical methods developed have been applied to data of Shah and Langley on mitochondrial (mt)DNA from Drosophila melanogaster, simulans and virilis. This application has suggested that the evolutionary change of mtDNA in higher animals occurs mainly by nucleotide substitution rather than by deletion and insertion. The evolutionary distances among the three species have also been estimated.