山东省地方绵羊品种微卫星遗传多态性

利用24个微卫星标记，分析了山东省内原有地方绵羊品种的遗传多样性.结果表明，在来自4个品种共71个种群的164只绵羊中，共检测到等位基因467个，有效等位基因占49.59％，不同微卫星基因座之间的等位基因数差异大于品种之间的差异；发现特有等位基因123个，优势等位基因43个.在所有微卫星基因座中，89％处于Hardy-Weinberg不平衡状态，有50％属于中性基因座.不同品种的微卫星基因座多态信息含量呈高度多态（PIC＞0.5），Shannon指数较高（I＞1.5），平均观察杂合度（范围0.454～0.560）明显低于期望杂合度（范围0.831～0.849），证明4个地方绵羊种群具有丰富的遗传多样性和广泛的遗传基础，但品种内存在着一定程度的近交.聚类分析表明，山东地方绵羊品种遗传进化关系明确，可划分为鲁西地区的小尾寒羊和大尾寒羊、鲁东地区的山地绵羊和洼地绵羊两大类群，其遗传距离与地理分布距离相一致.

enetic diversity of indigenous sheep breeds in Shandong Province based on microsatellite markers study

By using 24 microsatellite markers, this paper studied the genetic diversity of four indigenous sheep breeds in Shandong Province. 467 alleles were detected from 164 sheep of 71 breeding groups, and the proportion of effective alleles was 49.59%. The differences of the allele number among microsatellite loci were larger than those among breeds. 123 peculiar alleles and 43 dominative alleles were found from these sheep. 89% of the microsatellite markers were not in Hardy-Weinberg, and 50% of them were neutral. All the microsattelite markers were of high polymorphic (PIC>0.5), and the values of Shannon indexes were relatively high. The observed heterozygosities (0.454~0.560) were significantly lower than their expected values (0.831~0.849). It was suggested that the four indigenous sheep breeds in Shandong Province were highly genetic polymorphic but somewhat inbred. The NJ and UPGRAM dendrograms indicated that the small-tailed and large-tailed Han sheep in west Shandong were closer in genetics, and the Shandi and Wadi sheep in east Shandong were similar. The genetic distances between different sheep breeds were accordant to geographical distances.