利用mtDNA Cytb基因探讨黔东南小香羊系统地位

Discussion on Phylogeny Status of Small Xiang Goat in Southeast of Guizhou Using Cyt b Gene Sequence in mtDNA

黔东南小香羊和贵州白山羊之间的遗传关系一直存在争议,为此,对黔东南小香羊16个个体和贵州白山羊13个个体细胞色素b基因全序列进行了测定,通过遗传多样性和系统发育分析,探讨黔东南小香羊系统地位。结果表明:在2个贵州山羊群体中共观察到8种单倍型,2种单倍型共享,其中,贵州白山羊有7种单倍型,黔东南小香羊有3种单倍型;黔东南小香羊单倍型多样性(Hd)为0.625,核苷酸多样性(Pi)为0.00189,贵州白山羊的Hd和Pi分别为0.923和0.00324,贵州白山羊遗传多样性比黔东南小香羊丰富。结合从GenBank中检索获得的野生山羊、岩羊、绵羊细胞色素b基因序列构建分子系统发生树,结果显示,黔东南小香羊和贵州白山羊与胃石山羊亲缘关系最近,与我国野生岩羊亲缘关系较远。

The genetic relation between Small Xiang Goat in Southeast of Guizhou and Guizhou White Goat remained controversial for a long time. The complete sequence of mitochondrial Cyt b gene from 16 individuals of Small Xiang Goat in Southeast of Guizhou and 13 Guizhou White Goat was determined in this paper to study the phylogeny status of Small Xiang Goat by genetic diversity and phylogenetic analyses. Results showed that 8 different haplotypes and 2 shared haplotypes were found among the 29 sequences in the 2 goat breed examined. Among them ,there were 7 haplotypes in Guizhou White Goat and 3 haplotypes in Small Xiang Goat. Haplotype diversity and nucleotide diversity in Small Xiang Goat were 0. 625 and 0.00189, while that in Guizhou White Goat were 0. 923 and 0. 00324. It indicated that genetic diversity in Guizhou white goat was more abundant than that in Small Xiang Goat. Combining with the molecular phylogenetic tree constructed by complete Cyt b gene sequences searched from GenBank from wild goats ,Pseudois nayaur （blue sheep） and sheep,it indicated that Small Xiang Goat had close genetic relationship with Guizhou White Goat and Capra aegagrus.