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, Fis 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 Fst 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.