新疆8个绵羊品种遗传多样性和系统发生关系的微卫星分析

为分析新疆北疆地区主要绵羊品种的遗传多样性和系统发生关系，利用10个微卫星标记，采用PCR扩增，12％非变性聚丙烯酰胺凝胶电泳、Sanguinetti银染法显色，对新疆北疆地区8个品种、1个杂交一代绵羊群体遗传多样性进行了检测，统计了各群体的等位基因组成、平均有效等位基因数(E)和平均基因纯合率，利用等位基因频率计算出各群体的平均遗传杂合度(h)、多态信息含量(PIC)和群体间的遗传距离。利用分子进化遗传分析软件，采用邻结法构建系统发生树；同时根据等位基因频率，利用PHYLIP(3．6)分析软件，采用最大似然法构建系统发生树，应用白举检验估计系统树中结点的白引导值，并进行了系统发生分析。结果表明：10个微卫星位点在9个绵羊群体中的多态信息含量除BMI824、MAF65为低、中度多态外，其余8个微卫星均为高度多态，可作为有效的遗传标记用于各绵羊品种的遗传多样性和系统发生关系的分析；所有绵羊群体的平均PIC(0．5631)、h(0．5721)和E(2．9)均低于国外其他品种的绵羊，其基因多态性和遗传多样性相对贫乏；新疆本地土种阿勒泰羊、哈萨克羊和巴什拜羊与国外引进绵羊品种及混有外血的本地培育品种遗传距离较远，他们聚为不同的两类，各绵羊品种的分子系统发生关系与其来源、育成史、分化及地理分布基本一致。

Microsatellite Analysis of Genetic Diversity and Phylogenetic Relationship of Eight Sheep Breeds in Xinjiang

To reveal the genetic diversity and syseighttemic relationship of main sheep breeds in north Xingjiang,the genetic polymorphisms of 10 microsatellites in 8 sheep breeds and one first filial generation (F 1) in north Xinjiang were studied by means of PCR,polyacrylamide gel electrophoresis and silver staining.Number of alleles,average effective number of alleles ( E ) and average rates of homozygote of each breeds were counted.According to allele frequencies of ten microsatellites,polymorphism information content ( PIC ),mean heterozygosity ( h ) and genetic distances were calculated for each breeds.By using the Neighbor joining method of Molecular Evolutionary Genetics Analysis software,a dendrogram was obtained based on genetic distances.Another dendrogram was obtained by Maximum Likelihood method in PHYLIP (3 6) software.The bootstrap values were evaluated for each crunode of the dendrogram by means of bootstrap test.The systemic relationship was analyzed as well.The results showed that 8 of 10 microsatellite loci were highly polymorphic,but BM1824 and MAF65 were low and medium polymorphic respectively,so the 8 microsatellite loci were effective markers for analysis of genetic relationship among sheep breeds.The average PIL(0 5631) , h (0 5721) and E (2 9) of the whole population was all lower than those of other sheep breeds reported in the documents,which showed the gene polymorphisms and genetic diversity in these sheep breeds are relative rare.The genetic distances of native Aletai,Kazak and Bashibai sheeps in Xingjiang from foreign sheep breeds and cultivated breeds bearing foreign bloodline are relatively large.Consequently,they clustered in two groups.The phylogenetic relationship between different sheep breeds was in accordance with their resourse,breeding history,differentiation and localities.