The relationship between MHC-DRB1 gene second exon polymorphism and hydatidosis resistance of Chinese merino (Sinkiang Junken type), Kazakh and Duolang sheep

The present study aimed at detecting the association of ovine major histocompatibility complex class II (Ovar II) DRB1 gene second exon and susceptibility or resistance to hydatidosis in three sheep breeds of Sinkiang. The MHC-DRB1 second exon was amplified by polymerase chain reaction (PCR) from DNA samples of healthy sheep and sheep with hydatidosis. PCR products were characterized by the restriction fragment length polymorphism (RFLP) technique. Five restriction enzymes, MvaI, HaeIII, SacI, SacII, Hin1I, were used, yielding 14 alleles and 31 restriction patterns. Frequencies of patterns MvaIbc, Hin1Iab, SacIIab, HaeIIIde, HaeIIIdf, HaeIIIdd (P < 0.01) in Kazakh sheep, SacIab (P < 0.05) in Duolang sheep, and HaeIIIab, HaeIIIce, HaeIIIde, HaeIIIee (P < 0.01) in Chinese Merino (Sinkiang Junken type) sheep, were significantly higher in healthy sheep compared with infected sheep. These results indicated a strong association between these patterns and hydatidosis resistance. In contrast, the frequencies of MvaIbb, SacIIaa, Hin1Ibb, HaeIIIef (P < 0.01) and HaeIIIab (P < 0.05) in Kazakh sheep, SacIbb, HaeIIIae, Hin1Iab (P < 0.05), HaeIIIaa, HaeIIIbe, HaeIIIef (P < 0.01) in Duolang sheep, SacIIaa (P < 0.05) and HaeIIIbd, Hin1Ibb, HaeIIIcf, HaeIIIef (P < 0.01) in Chinese Merino sheep (Sinkiang Junken type) were significantly lower in healthy sheep compared with infected sheep. This indicated a strong association between these patterns and hydatidosis susceptibility. In addition, sheep with the pattern of HaeIIIef demonstrated a high hydatidosis susceptibility (P < 0.01) in all three breeds, while sheep with the pattern HaeIIIde demonstrated significant hydatidosis resistance (P < 0.01) in Kazakh and Chinese Merino sheep (Sinkiang Junken type). These results suggest that the Ovar-DRB1 gene plays a role in resistance to hydatidosis infection in the three sheep breeds. Le but de cette étude était de rechercher les associations éventuelles entre le deuxième exon du gène DRB1 du complexe majeur d’histocompatibilité de classe II (Ovar II) et la susceptibilité ou la résistance à l’échinococcose chez trois races de moutons au Sinkiang. Le deuxième exon a donc été amplifié par PCR à partir d’échantillons d’ADN de moutons sains ou infectés. Les produits de PCR ont été caractérisés par la technique de polymorphisme de la longueur des fragments obtenus après digestion enzymatique. Cinq enzymes ont été utilisées : MvaI, HaeIII, SacI, SacII, Hin1I, produisant 31 profils de res