我国6个地方绵羊品种微卫星DNA多态性研究

利用聚丙烯酰胺凝胶电泳技术研究了我国蒙古羊、乌珠穆沁羊、哈萨克羊、阿勒泰羊、滩羊和藏绵羊 6个地方绵羊品种 17个微卫星标记的多态性 ,以探讨其遗传多样性、起源分化及群体间的遗传亲缘关系。结果表明微卫星标记不同位点间遗传多样性差异极显著 (P <0 0 1) ,群体间多态信息含量 (PIC)、近交程度 (Fis)和观察杂合度 (Obs .Het)差异不显著 ,但基因多样性 (genediversity)和期望杂合度 (Exp .Het)差异显著 (P <0 0 5 )。所研究的我国 6个地方绵羊品种与欧洲品种具有相似的遗传多样性 ,但具有较高的近交系数。个体和群体的聚类分析结果提示我国地方绵羊品种可能起源于两类祖先。群体间的聚类分析结果还表明 ,蒙古羊与乌珠穆沁羊分化不明显且具有较近的遗传亲缘关系 ,蒙古羊与藏绵羊间分化明显且具有较远的遗传亲缘关系。滩羊、阿勒泰羊以及藏绵羊间也具有较近的遗传亲缘关系。所研究的我国 6个地方绵羊品种的遗传分化 (Fst)与西班牙绵羊品种接近 ,但明显小于欧洲其他绵羊品种

Study on Polymorphisms of Microsatellites DNA of Six Chinese Indigenous Sheep Breeds

The polymorphisms of 17 microsatellites loci of six indigenous sheep breeds,including Mongolian sheep,Ujumuqin sheep,Kazakstan sheep,Aletai sheep and Tibetan sheep,were studied using polypropylene gel electrophoresis in order to investigate their genetic diversity,origin,differentiation and relationships.The results indicated that there was a significant difference in genetic diversity between different loci (P<0.01).There was no significant difference in PIC,F_(is) and observed heterozygosity (Obs.Het) among populations (P>0.05),but a significant difference in gene diversity and expected heterozygosity (Exp.Het) (P<0.05).Chinese indigenous sheep breeds had similar genetic diversity as those from Europe,but with higher inbreeding coefficient.It could be inferred from the cluster of individuals and populations that Chinese indigenous sheep breeds might originate from two ancestors.The cluster of populations showed that Mongolian sheep and Ujumuqin sheep had close relationship and did not differentiate obviously.Mongolian sheep and Tibetan sheep had far relationship and differentiated significantly.Aletai sheep differentiated from Kazakstan sheep but not significantly.Tan sheep,Aletai sheep and Tibetan sheep also had close relationships.The F_(st) of Chinese indigenous sheep breeds was close to some Spanish sheep breeds,but much smaller than that of other European sheep breeds.More loci and samples should be studied in the future in order to obtain more accurate results.