中国4个牛种MSTN基因外显子2多态性分析与其系统发生关系研究

Study on the Polymorphism and Phylogenetic Relationship of MSTN Gene Exon 2 in 4 Bovine Species in China

[目的]解决牛亚科动物近缘物种的分类归属问题,了解牛亚科各种群遗传多样性。[方法]采用酚-氯仿抽提法从4个中国牛种中提取基因组DNA,对MSTN基因进行PCR扩增和测序,构建系统发育树,探讨4个牛种间MSTN基因外显子2的系统发生关系。[结果]MSTN基因外显子2编码区为372 bp。蒙古牛、牦牛和独龙牛的MSTN基因外显子2具有丰富的多态性。在所测66个样本中存在3个核苷酸多态位点,定义了6种单倍型。雷琼牛、蒙古牛、独龙牛与巴州牦牛享有共同的单倍型。巴州牦牛独自聚成一支,而雷琼牛与一部分独龙牛、大部分蒙古牛和引用瘤牛聚成一支。[结论]蒙古牛、雷琼牛、独龙牛种间存在着基因交流。牦牛与普通牛、瘤牛的分化较明显,比瘤牛与普通牛的亲缘关系要远。

[Objective] The research aimed to solve the taxonomic problem of the closely-related species of Bovinae and understand the genetic diversity in different populations of Bovinae. [Method] Genomic DNA was extracted from 4 Chinese Bovinae species by using phenol - chloroform extraction method. And PCR amplification and sequencing was made on MSTN gene and the phylogenetic tree was constructed to discuss the phylogenetic relationship ofMSTN gene exon 2 in 4 bovine species. [Result] The length of the coding region of MSNT gene exon 2 was 372 bp. MSTN gene exon 2 in Mongolian cattle, Yak and Dulong cattle had abundant polymorphism. Three nucleotide polymorphinic sites existed in 66 determined samples and 6 kinds of haplotypes were defined. Leiqiong cattle and Mongolian cattle had one kind of common haplotype, and both Dulong cattle and Bazhou yak had other of common haplotype together. Bazhu yak was classified into one branch itself, while Leiqiong cattle, some Dulong cattle, most Mongolian cattle and zebu were classified into the other branch. [Conclusion] Gene intercommunion was existed among Menggu cattle, Leiqiong cattle and Dulong cattle. The genetic differentiation between yak and Bos Taurus. zebu were more obvious and its genetic relationship with zebu and Bos Taurus were farther.