Association analysis between myxo-virus resistance gene (Mx) S631N polymorphism site and immune traits and production performance of BAI chicken breeds
Abstract：In the experiment, PCR-RFLP technique was used to detect the alleles distribution of S631N polymorphism site of myxo-virus resistance gene (Mx) in BAI chicken populations. Populations with different genotypes were constructed by selected mating method. After vaccine were injected the Newcastle Disease (ND) and Avian Influenza (AI) antibody titers of individuals with different genotypes were respectively measured at 35, 42, 49, 70 and 100 days of age using haemagglutination activity (HA) text and hemagglutination inhibition (HI) text. The body weight of 90 days, age at first laying and egg number at 72 weeks of individuals with different genotypes were also measured. The association between the polymoephism site and immune traits and production performance were analyzed. The resulted showed the allele frequencies at this locus was in Hardy-Weinberg equilibrium (P>0.05) in BAI populations, the frequencies of three different genotypes were 0.233(AA), 0.517(AG) and 0.250(GG). In tested days, the ND and AI antibody titers with different genotypes had the same increased and decreased laws, but individuals with AA genotypes had higher levels (P<0.05) than that of AG and GG genotypes in several tested days. The association analysis showed this polymorphism site had significant effect (P<0.05) on peak ND antibody titer of 49 days and AI antibody titer of 70 days. However, the body weight of 90 days, age at first laying and egg number at 72 weeks had no variation among individuals with different genotypes. The results identified the S631N polymorphism site of Mx gene as an important candidate mark for improving antiviral activity.
