The interactive effects of speciation and introgression on the mitochondrial DNA evolution in Drosophila

果蝇线粒体DNA进化中物种形成和基因渗入的相互作用

基本信息

批准号：
15570082
负责人：
TAMURA Koichiro
金额：
$ 2.37万
依托单位：
Tokyo Metropolitan University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2005
项目状态：
已结题

项目摘要

The nucleotide substitution rate for mitochondrial DNA (mtDNA) is generally much faster than that for nuclear DNA in higher animals, which makes mtDNA useful to detect a difference between closely related species. However, phylogenetic relationships of mtDNA often show conflicts with the species relationships due to ancestral polymorphisms and geographic population subdivisions. For instance, the mitochondrial introgression, which totally disrupts the correspondence between mtDNA and species phylogenies, has been reported repeatedly between closely related species in a sympatric condition.To clarify the interactive effects of speciation and introgression on the mtDNA evolution, the sequence divergences of mtDNA (cytochrome c oxidase subunit 1 gene) and nuclear DNA (xanthine dehydrogenase and white genes) were investigated for species and subspecies of the Drosophila nasuta subgroup, which includes several closely related species and subspecies on the way of speciation and distributes in various condition from complete allopatry to sympatry depending on the geographic locations. The results show a strong correlation between geographic distances of habitats and sequence divergences of mtDNA, whereas it was not the case of nuclear DNA. Furthermore, evidence of frequent mitochondrial introgressions in the course of the D.nasuta subgroup evolution was indicated. In conclusion, the importance of taking geographic distribution pattern and the potential of introgression into consideration in the phylogenetic studies of mtDNA was suggested.Furthermore, for better performance of molecular phylogenetic analyses, theoretical studies were conducted to develop the statistical methods for estimating a neutral nucleotide substitution rate from protein coding sequences under a codon selection and a distance matrix for the reconstruction of large phylogenetic trees with the neighbor-joining method.

线粒体DNA（mtDNA）的核苷酸取代率通常比上等动物中的核DNA快得多，这使得mtDNA可用于检测密切相关的物种之间的差异。但是，mtDNA的系统发育关系通常与祖先多态性和地理种群细分所致的物种关系发生冲突。 For instance, the mitochondrial introgression, which totally disrupts the correspondence between mtDNA and species phylogenies, has been reported repeatedly between closely related species in a sympatric condition.To clarify the interactive effects of speciation and introgression on the mtDNA evolution, the sequence divergences of mtDNA (cytochrome c oxidase subunit 1 gene) and nuclear DNA (xanthine dehydrogenase研究了果蝇nasuta亚组的物种和亚种，研究了果蝇的物种和亚种，其中包括几种与物种形成方式的密切相关的物种和亚种，并根据地理位置的各种条件分布在各种条件下。结果表明，栖息地的地理距离与mtDNA的序列差异之间存在很强的相关性，而不是核DNA的情况。此外，在d.nasuta亚组进化过程中频繁线粒体插入的证据。总之，提出了采用地理分布模式和在mtDNA的系统发育研究中考虑的重要性。Furthermore为了更好地执行分子系统发育分析，进行了理论研究，进行了统计方法，用于开发用于估算蛋白质核苷酸序列的大型核苷酸序列的统计方法，该方法是估算蛋白质编码的距离序列序列的，并且是蛋白质编码的距离序列的距离序列的距离，该方法的核苷酸序列是一种距离的距离序列的距离。使用邻居加入方法。