Evaluating Genetic Diversity Of Chinese Sheep

The microsatellite loci are used in this experiment to analysis the genetic diversity of 500 sheep from ten indigenous breeds (UQ, TAN, HU, HBR, STH, AD, GB, GF, ZT, HZK) and one introduced breed (PD). It can be offered the basis of conversation and utilization of indigenous sheep breeds resource. We get some results as following:1. Based on the 22 microsatellites loci, we analyze the genetic variation of 11 sheep breeds and get 306 alleles and 13.91 in average, which show that the indigenous sheep have highly genetic diversity.2. We get the allele frequency. Accordingly, we calculate Ho,PIC and Ne among the 11 breeds, which is 0.688, 0.727, 4.838 respectively. The results show that the genetic variations are abundant.3. The genetic diversity of indigenous breeds is higher than the introduced breed-Poll Doset on Na, Ne, Ho, He and PIC.4. We analysis the gene flow among breeds. We find the level of gene flow between HZK sheep and HBR sheep is very high, followed that between UQ sheep and HBR sheep. The gene flow between GF sheep and the others is very low, and the gene flow among the others is almost in the same level. We draw this conclusion that the gene exchange among populations is relatively active.5. We calculate the HT,HS and Gst. We find the genetic variation between populations is 4.96% of that of total population. We safely draw a conclusion that the genetic variation between populations is not high, the genetic variation within population is the main source of the total variation.6. We get the Dcoa, DA and Ds genetic distance by the GDA and DISPAN program. The results show that the genetic distance among populations vary inapparently. According to the three genetic distances, we make NJ and UPGMA cluster. The reconstruct tree show that DA/NJ dendrogram give a real genetic relationship with 11 breeds, and NJ cluster is better used in this study.7. The results show that there exist significant genetic differentiation between ZT sheep and the other breeds by the PCA and FCA analysis.8. According to the result of Structure program, we find that the genetic relationship between ZT sheep and Mongolia breeds is closer than that between ZT sheep and Tibet breeds. And the result confirms that DianZhong plateau is the origin area of ZT sheep other than Tibet.