Polymorphisms in Exon 2 of MHC Class II DRB3 Gene of 10 Domestic Goats in Southwest China

Polymorphism of the second exon of the caprine leukocyte antigen-DRB3 gene (CLA-DRB3*02) was investigated in this study. The 285 bp PCR product of 258 individuals from 10 domestic goat breeds in Southwest China was digested with restriction endonucleases PstI and HaeIII and then genotyped. Three alleles and 4 restriction digestion profiles were distinguished by digestion of the PCR fragment by PstI, and 8 alleles and 13 genotypes by HaeIII. For HaeIII restriction enzyme sites, the Chi-square (X-2) test showed that all goat breeds in this study did not fit with the Hardy-Weinberg equilibrium (p<0.01 or p<0.05). The highly polymorphic nature of CLA-DRB3*02 was demonstrated and the ranges of gene heterozygosity (He) and polymorphism information content (PIC) were 0.36-0.63 and 0.32-0.55, respectively. Clustering analysis showed that the 10 goat breeds clustered into two groups and Dazu Black goat had a close genetic relationship with Chengdu Grey, Jintang Black and Nanjiang Yellow goats.