Microsatellite Analysis Of The Genetic Diversity In Thirteen Sheep Breeds In Xinjiang

Genetic diversity of thirteen sheep breeds in Xinjiang was evaluated on the basis of 10 microsatellite markers selected from the sheep Gene-Bank. Allele frequencies were estimated based on band presence or absence. Average breed polymorphism information content,heterozygosity,genetic distance and Coefficient of genetic differentiation were calculated based on allele frequencies And then, cluster analysis based on those calculated genetic distances lines was performed for the thirteen sheep breeds.All the microsatellite loci analyzed were polymorphic in those chicken lines with an average number of alleles per locus and the average polymorphism information content (PIC) equal to 7.3 and 0.6803 (0.5644~0.7771) respectively. Average heterozygosity of groups was 0.7192 (0.6754~0.7530), and the significantly higher heterozygosity suggested that the sheep breeds had abundant genetic diversity and potential of selection in Xinjiang Province.PopGene32 was used for analyzing F-statistic parameter estimation and gene flow of 10 microsatellite loci in groups. The results showed that: the mean value of inbreeding coefficient (Fis) within subgroup was 0.0565, and the mean value of inbreeding coefficient (Fit) in all groups is 0.1066, the results indicated that certain heterozygotes existed in 13 sheep groups; The genetic differentiation coefficient (Fst) within subgroup was only 0.0531, it means that genetic variation between groups is 5.31%, and the genetic variation within groups is 94.69%, this results suggested that gene flow occurred in the selected groups, or occurred during a certain period in the past,which may be associated with the breeding history of the species.The Genetic distance was also calculated, and the results showed that there is a certain degree of genetic distance in the sheep breeds, and the genetic distance between Chinese Merino sheep and the Aletai sheep was largest, equaled to 0.3132, while the genetic distance between Bashibai sheep and Farm Hetian sheep was lowest, equaled to 0.0690. UPGMA cluster analysis showed that the Kirgiz sheep and Duolang sheep was clustered first due to a relatively small genetic distance between them, and then they clustered with the Altay sheep, that was consistent with the geographical distribution; Chinese Merino sheep and Xinjiang fine-wool sheep clustered together, they clustered with the other finally, that was consistent with the breeding history. Those cluster analysis results are basically the same as the expected results in accordance with morphological and breeding history, and indicated that microsatellite markers was suitable for study of population genetic structure and genetic relationship, and also was a useful tool for the study and protection of genetic diversity of livestock and poultry.