The genomes of six populations(Dorset,Texel,Black-Suffolk,Tan sheep,Small-tailed Han sheep,hybrid of Tan and Small-tailed Han sheep) were screened with 7 microsatellite loci,and genetic diversities and genetic distance were estimated in this study.The results showed that,108 alleles were detected in six populations,all the loci showed polymorphism in each population.The expected heterozygosity of all populations were much higher than the observed heterozygosity.The coefficient of phenotype differentiation(Fst) between populations was very low,the value was 5.8%,which was consistent with the coefficient of gene differentiation(Gst).The inbreeding coefficients for all populations(Fit) amounted to 56.90%.The inbreeding coefficients within breeds(Fis) was 54.36%.The heterosis between populations was also forecast according to DC distance and Nei's genetic distance(DA),hybrid with Tan and small-tailed Han sheep as female parent was the best,then was Tan sheep,and Small-tailed Han sheep was the worst.The selective order for male parent should be Texel,Black-Suffolk,and then Dorset concerned with hybrid effects.

The genomes of 6 populations were screened by using microsatellites as molecular markers,including Ujmuqin sheep,small-tailed Han sheep,Tan sheep,Hu sheep,Tong and Yangtse River Delta White Goat.A total of 7 microsatellite markers were used and genetic diversity and genetic distance were also determined.The results showed that there were 224 alleles in 6 populations,all 7 locus showed polymorphism in all populations.Average heterozygosity of all populations was 0.9499,and the mean polymorphism information content(PIC) of all 6 populations was 0.8425~0.9294.A UPGMA dendrogram was constructed based on Nei′s standard genetic distance and DA genetic distance respectively.Hu and Tong were grouped at first,Ujmuqin and small-tailed Han clusted and then clusted with Tan sheep,Finally Yangtse River Delta White Goat clusted with all above.From this study,Ujmuqin is belong to Mongolia sheep group,it correspond with the historical records exactly.Ujmuqin and small-tailed Han sheep,Tan sheep,Hu sheep,Tong sheep,vest in Mongolia sheep group.

The Callipyge sheep produced some muscle hypertrophy,because of a single nucleotide mutation A-G at the end of the 18th chromosome.Callipyge gene is belonged to the imprinted gene family,performancing paternal polar dominance.The Callipyge gene may affect one cis-acting element LRCE(long range control element),activate one enhancer or inhibit one silencer.Callipyge sheeps have the higher rates of the lean and the slaughter than the average,but the longissimus have the higher shear strength and affect the taste.Callipyge gene can be used!in the breeding of the sheeps.