Abstract
POLYMORPHISM OF EXON 14 OF THE MX1 GENE AND ITS RELATIONSHIP WITH CYTOKINES AND REPRODUCTIVE PERFORMANCE IN MEISHAN PIGS

A large number of studies have shown that the polymorphism of exon 14 of the Mx1 gene is related to antiviral ability. In order to further explore the feasibility of exon 14 polymorphism of the Mx1 gene as an effective genetic marker for resistance breeding in Meishan pigs, PCR-RFLP analysis of exon 14 of Mx1 gene was conducted and the associations with some cytokines (IL-1β, IL-4, IL-6, IL-8, TGF-1β, IFN-γ, TNF-α and IL-10) and reproductive performance within different parities were analyzed. The results showed that there was a G36T mutation in exon 14 of Mx1 gene in Meishan pigs, and three genotypes were detected by PCR-RFLP, which were defined as AA, AB and BB. Furthermore, the level of IL-8 was significantly higher in the AB genotype than in the BB genotype (P< 0.05). There were no significant differences of the other cytokine levels among these three genotypes (P > 0.05). Association analysis of the reproductive performance indicated that the traits of total number born, number born alive, number of weaned piglets, primary litter weight, weaning litter weight and weaning survival rate do not have significant differences (P > 0.05) among the three genotypes in the first and multiparous sows. These suggested that the G36T locus of exon 14 of Mx1 gene can be used as a potential genetic marker site for pig disease resistance breeding, and it cannot adversely affect the reproductive performance of the body while improving the disease resistance.