四川7个地方山羊品种(类群)mtDNA遗传多样性研究

测定了四川7个地方山羊品种（类群）43个个体的mtDNA控制区全序列，结果表明：山羊mtDNA控制区全序列长度为1212bp或1213bp，A＋T含量（59．9％）明显高于G＋c含量（40．1％）。共检测到74个变异位点，序列均为中性突变，核苷酸多样度为1．686％，这些差异共定义了27种单倍型，单倍型多样度为0．966，遗传多样性较为丰富，品种（类群）间存在不同程度的遗传分化。7个地方山羊品种（类群）间的遗传距离变异范围为0．0017～0．0306。用MEGA软件的NJ法构建单倍型序列的系统发育无根树，结果表明四川地方山羊品种（类群）有两个母系来源，但是否就对应于角笋骨羊（Capra aegagrus）和捻角山羊（Capra falconeri）两个野生祖先，还有待于进一步研究。

Study on Mitochondrial DNA Genetic Polymorphism of Seven Indigenous Goat Breeds(Groups) in Sichuan

Complete sequence of mitochondrial DNA(mtDNA) control region was sequenced in 43 individuals from 7 indigenous goat(Capra hircus)breeds(groups)in Sichuan province.The complete sequence of mtDNA control region was 1 212 or 1 213 base pair,and the content of A T(59.9%)was higher than that of G C(40.1%)significantly.74 sites were polymorphic and all of these sequences were neutral mutation.All sequence polymorphic sites defined 27 haplotypes.High nucleotide diversity(1.868%)and haplotype diversity(0.966) were manifested.These results suggested richer genetic diversity within Sichuan indigenous goat populations and genetic divergence among them.The Kimura 2-parameter distance among breeds(groups)varied from 0.001 7 to 0.030 6.Phylogenetic unrooted trees constructed with neighbour-joining methods showed two maternal origins in Sichuan indigenous goats.More detailed studies should be continued to indicate whether the two maternal origins are Capra aegagrus and Capra falconeri.