Genetic Diversity In 9 Sheep Populations Based On Microsatellite Analysis

Micosatellite mark was applied as one of molecular markers in recent years, which can effectively assess groups of genetic diversity, the estimated population genetics distance. the genetic diversities of 6 Chinese indigenous sheep populations (SU, ALT, BYBLK, HA, TY, HZ) and 3 introduced populations (PD, TX, SF) were investigated using 9 microsatellite DNA markers through fluorescence PCR. The markers were recommended by FAO and the ISAG. The allele frequencies, polymorphism information content (PIC), heterozygosity (He), effective number of alleles(Ne) and genetic distance were calculated, the genetic variability and populating structure about nine breeds were estimated. The results were as follows:1. It was shown by the result of microsatellite markers: nine of the microsatellite loci were polymorphic and effective markers for analysis of genetic diversity and relationship among sheep populations.2. From the number of alleles, heterozygosity and polymorphism information content shows that the genetic diversity of Chinese indigenous sheep breeds more abundant than the Poll Dorset, Texel and Suffolk, indicating that most of the conservation farms better preservation of genetic resources of local sheeps.3. The analysis for the structure of population showed that some of populations and locus were not in Hardy-Weinberg equilibrium; the absence of heterozygote was prominent in most of populations, which suggested the structure of population had changed and inbreeding at the different degree might existed. According to this situation, the farmers should take appropriate measurs to widen the genetic basis of species preservation, select genetic diversity of individuals as parents for propagation and reintroduction, to expand the distribution areas of small population, to improve its geographical isolation, established among certain gene flow.4. At nine loci the Fst was 0.113 and 11.30% 0f the genetic variation between populations. The results show that the genetic variation populations within is the main source of the total variation. 5. The UPGMA cluster and NJ cluster were made by DA genetic distance and a real genetic relationship can given from the UPGMA cluster with 9 sheep breeds. Both UPGMA dendrogram showed that the Chinese indigenous sheep populations and three introduced populations belong to different clades. Among the Chinese indigenous sheep populations the HZ populations was genetically more distant from the other sheep populations. The remaining five Chinese indigenous sheep populations were clustered into two clades. The first clade contained SU, ALT and BYBLK sheep populations, while the second clade was made up of TY populations. The result of software Principal component analysis was also supports this conclusion basically.The important conservation value of our major sheep breeds was covered in the Experiment and reference was provided about guiding genetic conservation of these species as well as Chinese indigenous sheep genetic resources conservation and utilization.