The Analyse Of The Relation Of Polymorphism Of DRB1,DQB1 Gene And Hydatidosis Chinese Merino And Duolang Sheep In Xinjiang

Major Histocompatibility Complex ( MHC ), also called Ovine Lymphocyte Antigen( OLA), is part of chromosomal region consisting of a group of closely linked and highly polymorphic loci. The antigens coded by DRB and DQB at MHC-Ⅱplay important roles in immune system, and have close relation with its functions. That the relationship between MHC and resistance/suseptibility to animal diseases/immune response/performance was closely linked. In this text, the polymorphisms of MHC-DRB1/DQB1 in Chinese merino and Duolang sheep with different intensity of infection hydatidosis were tested, and the relationship between MHC-DRB1/DQB1 and genetic resistance to hydatidosis was analyzed. Our research would help study the mechanisms of MHC-antidisease and provide data to anti-disease breeding, furthermore, which would have important theoretical and production value.1. The prevalence of E.granulosus was evaluated by ELISA diagnose Kit in Chinese merino sheep( 868 in total) in Tacheng, Yili, Shihezi and Duolang sheep( 351 in total) in Kashi. Results showed that the average infection rate of Chinese merino sheep were 22.33%, 48.8% and 6.9%, in Tacheng, Yili, Shihezi, respectively and that of total tested Dolang sheep and Chinese Merino sheep were 15.915% and 21.6% , both of which were significantly different (P﹤0.01).2. The polymorphisms of the second exon of MHC-DRB1 /DQB1 gene were investigated using the PCR-RFLP method in Duolang sheep and Chinese Merino sheep, results revealed that they were rich at SacII, Mval, SacI, Hin1I and HaeIII. In MHC-DRB1, 2, 3, 2, 2 and 6 RFLP patterns were found, and 3, 5, 3, 3, 15 and 3, 3, 3, 3, 18 genotypes were identified and base positions 229, 225, 208, 210, 178, 173, 159, 87 were polymorphic. In MHC-DQB1 gene, 2, 2, 4, 2, 3, 6 and 3 RFLP patterns were found with enzymes Mrox, ScaⅠ, SacII, NciI, TaqⅠ, MvaⅠand HaeⅢ, and 3, 3, 7, 3, 4, 16 and 6 genotypes were identified in Chinese merino sheep, and in Duolang sheep, 2,2,3,2,6,3 RFLP patterns with enzymes MroxⅠ, ScaⅠ, SacII, TaqⅠ, MvaⅠand HaeⅢ, and 3,3,5,2,14,5 genotypes, and base positions 266, 246, 231, 217, 213, 198, 192, 174, 161, 140, 96, 34 were polymorphic. According to above, we concluded the enzyme-digested sites of exon 2 of MHC-DRB1/DQB1 were in rich polymorphism, and in MHC-DQB1 in Chinese Merino sheep, allele HaeⅢm, HaeⅢn, MvaⅠz and MvaⅠy were new ones that found by cloning and sequencing.3. By comparing alleles and genotypic frequencies of MHC-DRB1 and MHC-DQB1 of healthy sheep with that of infectious ones in Chinese Merino sheep and Duolang sheep, we found that in Chinese Merino sheep, MvaⅠb, and HaeⅢe have some resistance to hydotydosis(P﹤0.01), genotype MvaⅠbb(p<0.01), HaeⅢee and SacⅠab may be resistant to hydotydosis, but MvaⅠbc, HaeIII bd, SacIIab and HaeIIIdf may be susceptible. MvaⅠD (P﹤0.05) , SacIIb, TaqⅠA and HaeⅢN were resistant to hydotidosis, TaqⅠB, MvaⅠC and HaeⅢM(P﹤0.01)were susceptible. MvaⅠDZ(P﹤0.05), TaqⅠAA and HaeIII NN were resistant, but MvaⅠCZ, TaqⅠAB(P﹤0.01)and HaeIII MN(P﹤0.01)were susceptible. In Duolang sheep, HaeⅢa(P﹤0.05)may be susceptible to hydotidosis, SacⅠab, HaeⅢcf and Hin1Ⅰaa(P﹤0.05) may be resistant. HaeIII be, HaeIII ef(P﹤0.01), SacⅠbb, HaeIII aa and Hin1Ⅰab(P﹤0.05)were susceptible in Duolang sheep at DRB1. MvaⅠD have resistance (P﹤0.01) to hydotidosis, MvaⅠDD and MvaⅠCD may be resistant, but MvaⅠBZ may be susceptible at DQB1.4. The relationship between halotype on MHC and hadytidosis was analyzed, results showed that in Chinese Merino sheep the halotype DRB-SacIAB, MvaIbb, DQB1-TaqIAA and HaeⅢNN have close relation with anti-hydytidosis ( P<0.01 ) , but DRB1-MvaIbc, DQB1-MvaIYY, DQB1-TaqIAB, DQB1-HaeⅢMN, DRB1-MvaIbb, DQB1-MvaICC, DQB1-TaqIAB and DQB1-HaeⅢMN were susceptible( P<0.01 ) . In Duolang sheep, DRB1-SacIAB, DRB1-HaeⅢff, DQB1-MvaICD, DRB1-SacIAB, DRB1-HaeⅢff and DQB1-MvaIDD were resistant to hydatidosis ( P<0.05 ) , but DRB1-HinIab, DRB1-HaeⅢbe, DRB1-HinIab, DRB1-HaeⅢef, DRB1-HinIab, DRB1-HaeⅢaa were susceptibl(eP<0.01).5. In this study, oncospheres were infected artifically with the healthy Chinese Merino sheep that halotype performed DRB1-SacIAB, DRB1-MvaIbb, DQB1-TaqIAA and DQB1-HaeⅢNN, all of which were confirmed to be resistant to hydytidosis.6. Hard-weinberg equilibrium plays an important role in maintaining the stability of genetic structure. It showed difference for Hardy-weinberg equilibrium of MHC-DRB1 in both sheep varieties. SacI and Hin1Ⅰin Chinese Merino sheep and MvaⅠin Dolang sheep have been attained to Hardy-weinberg equilibrium ( p>0.05 ) at MHC-DRB1, but others have not. TaqⅠand MroxⅠin Chinese Merino sheep and TaqⅠin Dolang sheep has been attained(P>0.05), but others have not(P<0.01)at MHC-DQB1...