蒙古家马和蒙古野马线粒体细胞色素b基因遗传多样性及系统进化分析

通过对马的线粒体细胞色素b（Cytb）基因序列的遗传变异分析，来探讨蒙古家马、蒙古野马和驴之间的亲缘关系和遗传多样性。对各类马和驴样本 mtDNA Cytb 基因进行PCR扩增和测序，运用现代分子生物学软件进行数据处理。结果共检测到15个单倍型，90个突变位点，单倍型多样性（Hd）为0.9356,核苷酸多样性（Pi）为0.01022,平均核苷酸差异数（K）为8.966，各群体间的遗传多样性相差不大。系统发育树和NETwork图中每一分支都至少包含2个群体的信息。4个类型蒙古家马总体上具有较高的遗传多态性，蒙古家马与蒙古野马之间的亲缘关系较近, 且出现数个分支，蒙古家马分布在各独立的进化支中，说明蒙古家马母系来源非常广泛或经过多次驯化。

Analysis of Genetic Diversity and Phylogeny of the Mitochondrial Cytochrome b Gene of Mongolian Horses and Mongolian Wild Horse

Genetic relationship and genetic diversity among Mongolian horses, Mongolian wild horse and donkeys were investigated by genetic variation analysis of the mitochondrial cytochrome b (Cytb) gene sequence. mtDNA Cytb gene of all samples were detected by PCR amplification and then sequenced. The date was analyzed by modern molecular biology software and the analysis showed that 90 polymorphic loci formed 15 haplotypes and the haplotype diversity (Hd), nucleotide diversity (Pi) and average number of nucleotide differences(K) were 0.9356, 0.01022 and 8.966, respectively. Genetic differences between the groups were not obvious. By construction of phylogenetic tree and NETwork, the results indicated that genetic diversity of 4 kinds of Mongolia horse were higher, Mongolian horse and Mongolian wild horse had close relationship and appeared several branches, which explained that Mongolian horses originated multiply or had been domesticated many times.