The Analyse Of The Relation Of Polymorphism Of MHC-DRB1 Gene And Hydatidosis In Xinjiang Duolang And Chinese Merino Sheep

Echinococcosis is a cosmopolitan zoonosis caused by adult or larval stages of cestodes belonging to the genus Echinococcus,in particular, in western of China, such as Xinjiang, Qinghai, Gansu, Ningxia, et al. Larval infection (hydatid disease, hydatidosis) is characterized by long-term growth of metacestode (hydatid) cysts in the intermediate host. The two major species of medical and public health importance are Echinococcus granulosus and E. multilocularis, which cause cystic echinococcosis (CE) and alveolar echinococcosis (AE), respectively.In recent year, with the development in science and technology, as well as improvements in prevention, diagnosis and treatment of disease, the incidence rate of Hydatid disease in human and domestic animal populations has drastically dropped. However, the process of eradicating remains hampered by lack of knowledge regarding the genetic interplay between the host and parasite. After infected by Hydatid disease, the hosts may depend on their immune system to defend to the infection, survives and the growths. So, the MHC and Hydatid disease resistance research will be a great help to control the prevent and eradicate Hydatid disease. We examined the abundance and prevalence of infection of E. granulosus by ELISA diagnose Kit which we had evaluated in Chinese merino and Duolang sheep in part of Xinjiang with ELISA diagnose kit. The result showed that the average infection rate was 21.6% in Chinese merino in north of Xinjiang, but 11% in Duolang sheep in south of Xinjiang. But in Tacheng,Yili and Shihezi the average infection rate was different in Chinese merion sheep, Tacheng 22.33%, Yili 48.8%, Shihezi 6.9%.The ovine major histocompatibility complex (Ovar) classⅡDRB1 second exon was amplified by nested polymerase chain reaction (PCR) from 192 Duolang and 199 Chinese merino sheep, each breed have 70 and 98 sheep infection with Hydatidosis. PCR products were characterized by the RFLP technique using three restriction enzymes, SacI, Hin1I and HaeIII. The results revealed extensive polymorphisms 2 ,2 and 6 RFLP patterns were found with enzymes SacI,Hin1I and HaeIII, 3, 3, 18 and 3, 3, 15 kinds of genotypes were identified in Duolang sheep and Chinese merino sheep respectively. By analyzing the restriction map of the DNA sequence of the second exon of the MHC-DRB1 gene, it was shown that the polymorphic sites were at base positions 159,173,177,178,208,and 225.By analyzing alleles and genotypic frequencies between healthy and infection with hydatidosis sheep, we found that allele HaeIII a was associated with susceptibility in Duolang (P﹤0.05), and genotype SacI ab and HaeIII cf were associated with resistance(P﹤0.05), but the genotypes of SacI bb, Hin1I ab and HaeIII aa were associated with susceptibility (P﹤0.05), especially the genotypes of HaeIII be and HaeIII ef (P﹤0.01). But in Chinese merino sheep allele HaeIII d was associated with susceptibility (P﹤0.05), and genotypes SacI ab and HaeIII ee were associated with resistance(P﹤0.05), but the genotype of HaeIII bd was associated with susceptibility(P﹤0.05).