Genetic Diversity Of Ewes For The Core Population In Yanchi Tan Sheep Using Microsatellite Markers

This study of ewes in the core population of Yanchi in Ningxia are from one of Tan sheep breeding population and randomly selected to screen 96 qualified individuals,then the 32 microsatellite markers were employed,which were qualified from collective literature and bench work checked all out.Analysis of genetic diversity and co-relationship between molecular genotype and measured phenotype(body size traits)to the 96 samples were carried out.The experimental results are as follows:1.Three of the 32 microsatellite loci,named URB024,BMS1678 and CP 16,have been exclude being lack of diversity or enough alleles as using standars.Among the remaining 29 microsatellite loci,DU264615,HUJ625 and BM2504 were moderately polymorphic,while the other 26 microsatellite loci showed high polymorphism.The average allele number of these 29 microsatellite loci to the ewes in the core population of Yanchi Tan Sheep is 9.5000,the following other results were obtained:the average effective numbers of alleles,the average expected heterozygosity,the average observed heterozygosity,and the average polymorphism information content were,4.4100,0.7224,0.6434 and 0.6918,respectively.2.Through analysis,we observed a correlation between MAF33 and body height and chest depth(P<0.05),and BMS1788 was associate with rump height and chest circumference(P<0.05 or P<0.01).Also,5 microsatellite markers including BL41,BMS835,BOVILS56,MAF33 and BMS500 had significant effects on the cannon circumference(P><0.01).The genotype 151/155 of the microsatellite locus MAF33 may have negative effects on body height and chest depth(P<0.05).The BMS1788 for the genotype 184/188 may have a positive effect on individual's height at the hip(P<0.05),and genotype 178/194 may have a negative effect on individual's chest circumference(P<0.05).The genotype of 115/133 in BMS835 and genotype 221/230 in BOVILS56 of microsatellite loci may have positive effects on individual shank circumference(P<0.05).3.Compareed with the data in Chinese sheep Breeds Records and literature,the body weight in adult of Tan ewe has increased markedly through the mesurements of random graze forbidden and improved breeding after several years.The results showed that the ewe in the core population of Tan sheep in Yanchi was riched in genetic diversity,and there was no obvious genetic differentiation or emergence of new gene groups.The results of conservation,breeding and environment improvement indicated that the genetic improvement of the Tan sheep population would be promising prospects.The 6 microsatellite loci might be further used in marker-assisted selection in Tan sheep.