Analysis On Genetic Diversity In Sheep Breeds In Gansu Province By Microsatellite Markers

The microsatellite markers were used in this experiment to analyze the genetic diversity of five local sheep breeds in Gansu province (Minxian Black Fur sheep, Tibet sheep, Mongolia sheep, Lanzhou large-tailed sheep, Tan sheep), one improved breed (Gansu alpine fine-wool sheep)and seven introduced breeds(Small-tailed Han sheep, Australian merino, German merino, Texel, Borderdale, Poll Dorset , Suffolk) at fifteen microsatellite loci. The objects were to offer the scientific data for protecting and utilizing sheep genetic resources. Main results were as following:1. By determining genetic diversity of 15 microsatellite loci in 13 sheep breeds, 229 alleles were detected, the average alleles at each loci were 15.3. There were the most alleles at the locus OarFCB128, while the least alleles at the locus OarAE129. So, the sheep breeds in Gansu Province had rich genetic diversity.2. As for 15 microsatellite loci in 13 sheep breeds, the polymorphism information content ranged from 0.793 to 0.902, the heterozygosity ranged from 0.8692 to 0.8921. Therefore, in this study, the 15 microsatellite loci analyzed were highly polymorphic, which can be used to evaluate the genetic diversity in sheep.3. Nei's genetic distance ranged from 0.1116 to 0.2427, Nei's standard genetic distance ranged from 0.0758 to 0.3878. The genetic distance between Minxian Black Fur sheep and Tibet sheep was the smallest(DA =0.1116,Ds=0.1383) .The genetic distance between introduced breeds and local sheep breeds was larger.4. 13 sheep breeds were clustered into three groups. Lanzhou large-tailed sheep, Tan sheep, Mongolia sheep, Small-tailed Han sheep , Tibet sheep and Minxian Black Fur sheep were grouped. Gansu alpine fine-wool sheep, German merino, Australian merino were grouped. Borderdale, Texel, Suffolk, Poll Dorset were grouped.