根据线粒体3个基因确定马属动物系统发育关系

Determination of the Phylogenetic Relationship of Equus Animals Based on Three Mitochondrial Genes

[目的]马属动物因其化石证据发掘充足,已经成为物种进化的最佳例证,但化石证据尚存在断层或者彼此难以区分等问题。旨在从分子水平上对马属动物的遗传分化、亲缘关系等方面的鉴定提供根本认识,为马属动物的保护和开发利用提供一些帮助,并为生物学教学提供基本的教学资料。[方法]采用分子生物学软件,通过比对在GenBank中提交的马属动物线粒体DNA(mtDNA)序列,检测单核苷酸突变(SNP)位点,并对检测到的单核苷酸突变进行系统发育分析。[结果]3个线粒体基因(COX1、Cytb和ND4)存在丰富的遗传变异,能够揭示出现存马属动物间的亲缘关系。[结论]3种基因构建的系统发育树的拓扑结构基本一致,都是白犀牛作为外群,马和普氏野马序列先聚在一起,3种亚洲野驴聚在一起,所有的斑马聚在一起,驴和斑马再聚在一起。

[Objective] Because abundant fossil evidences of Equus animals were discovered, it has become the best example of species evolution. However, there are still other troublesome issues in fossil evidences,such as the gaps in the fossil record and difficulty to distinguish from each other. The aim of this study was to provide some understandings for the genetic differentiation and genetic relationship identification of Equus animals at molecular level, provide some helps for the protection, exploitation and utilization of Equus animals and provide basic teaching materials for the teaching of biology. [Method] The molecular biology softwares were used to align the mitochondrial DNA（mtDNA）sequences in GenBank. Single nucleotide polymorphism（SNP）sites were detected. And the phylogenetic analysis based on SNPs was conducted. [Result] Abundant genetic variations were found in three mitochondrial genes（COX1, Cytb and ND4）, which could reveal the genetic relationship of Equus animals.[Conclusion] The topological structures of the constructed phylogenetic trees based on the three genes were basically the same. In the three trees, white rhinoceros sequences were all placed as the outgroup. And Przewalskii horse sequence was clustered with horse sequence firstly. Then the three kind of Asian wild ass were clustered. All zebra sequences were clustered firstly and then they were clustered with the donkey sequence.