Analysis of European mtDNAs for recombination
Analysis of European mtDNAs for recombination
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DOI：
10.1086/316938
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发表时间：
2001-01-01
影响因子：
9.8
通讯作者：
Howell, N
中科院分区：
文献类型：
--
作者：
Elson, JL;Andrews, RM;Howell, N
标准范式假定人类线粒体基因组（mtDNA）严格是母系遗传的，因此，mtDNA谱系是克隆的。由于mtDNA的克隆性，系统发育和群体遗传分析因此应该免于双亲本重组所带来的复杂性。事实上，mtDNA在人类分子进化分析中的使用取决于克隆性，这也是法医研究和了解致病性mtDNA突变在家庭内传播的关键条件。然而，这一范式最近受到了埃尔-沃克及其同事的挑战。通过两种不同的测试，他们得出结论，重组有助于mtDNA多态性在人类群体中的分布。我们已经建立了一个数据库，其中包括64个欧洲和2个非洲mtdna的完整序列。当这组序列用三种方法中的任何一种来分析时，没有证据表明mtDNA重组，这是埃尔-沃克和他的同事们的一种测试。当他们对过量同型性的测试应用于我们的序列集时，只观察到轻微的过量同型性。我们讨论了我们的结果不同于埃尔-沃克及其同事的可能原因。当我们把不同的结果放在一起时，我们的结论是，在人类进化过程中，mtDNA重组的频率还不够高，不足以推翻标准范式。
The standard paradigm postulates that the human mitochondrial genome (mtDNA) is strictly maternally inherited and that, consequently, mtDNA lineages are clonal. As a result of mtDNA clonality, phylogenetic and population genetic analyses should therefore be free of the complexities imposed by biparental recombination. The use of mtDNA in analyses of human molecular evolution is contingent, in fact, on clonality, which is also a condition that is critical both for forensic studies and for understanding the transmission of pathogenic mtDNA mutations within families. This paradigm, however, has been challenged recently by Eyre-Walker and colleagues. Using two different tests, they have concluded that recombination has contributed to the distribution of mtDNA polymorphisms within the human population. We have assembled a database that comprises the complete sequences of 64 European and 2 African mtDNAs. When this set of sequences was analyzed using any of three measures of linkage disequilibrium, one of the tests of Eyre-Walker and colleagues, there was no evidence for mtDNA recombination. When their test for excess homoplasies was applied to our set of sequences, only a slight excess of homoplasies was observed. We discuss possible reasons that our results differ from those of Eyre-Walker and colleagues. When we take the various results together, our conclusion is that mtDNA recombination has not been sufficiently frequent during human evolution to overturn the standard paradigm.