Analysis of genetic diversity and phylogeny among 7 sheep populations using microsatellite DNA marker.

Two hundred sixty eight samples from 7 sheep(Ovis aries) population including Gansu Tibetan sheep, Gannan Tibetan sheep, Qinghai Tibetan sheep, Hu sheep, small-tailed Han sheep, Tan sheep and Minxian Black Fur sheep were involved to detect the alleles in 15 microsatellite DNA loci.Results showed that total 187 alleles were discovered in 15 microsatellite DNA loci.And 43 populationloci deviated from the Hardy-Weinberg equilibrium.The number of the deviation in Hu sheep was the largest among the investigated populations.The population heterozygosity analysis showed that Qinghai Tibetan sheep had rich genetic diversity, while Hu sheep and Minxian Black Fur sheep were lower than others.The genetic distance and phylogenetic tree results showed that the Hu sheep, Tan sheep and the small-tailed Han sheep's relationship were closer than that of other populations, which had the same ancestor.The genetic structure showed that 7 populations could be divided into three genetic clusters.Small-tailed Han sheep, Tan sheep and Hu sheep belonged to a cluster, Qinghai Tibetan Sheep, Gannan Tibetan sheep and Gansu Tibetan sheep to another cluster, while Minxian Black-fur sheep to the third cluster.