Relationship between polymorphism of MHC-DRB1 gene and hydatidosis resistance in Kazak sheep.

To analyze genetic correlations between polymorphism of MHC-DRB1 gene and hydatidosis resistance in Kazak sheep,the polymorphism of exon 2 from MHC-DRB1 in 100 healthy and 100 infected sheep were detected by nested PCR SSCP.Results showed that the extensive polymorphism of exon 2 from MHC-DRB1 was detected and there were 37 genotypes controlled by 15 alleles.Results of χ2 test showed that patterns of MHC-DRB1 were significantly deviant from Hardy-Weinberg equilibrium(P0.01).By comparing alleles and genotypic frequencies of MHC-DRB1 in healthy Kazak sheep with those in infected ones,and to analyze the relative risk(RR) value,allele H(P0.01,RR=0.394) and F(P0.01,RR=0.465),as well as genotype FF(P0.05,0.352) and GH(P0.05,RR=0.45),were proved to have strong correlation with hydatidosis resistance.Allele B(P0.01,RR=14.54.1) and genotype GG(P0.01,RR=13.5) have the strongest predisposition to hydatidosis.And allele K(P0.01,RR=3.76) and G(P0.01,RR=3.395),as well as genotype KK(P0.05,RR=3.996),also has stronger predisposition to hydatidosis.Application of nested PCR-SSCP method confirmed the extensive polymorphism of Kazak sheep MHC-DRB1 genes and reported that the alleles and genotypes were relevant to the resistance or susceptibility of echinococcosis in Kazak sheep.