Abstract：The major histocompatibility complex (MHC) gene in chicken, which has a high degree of polymorphism and stability, and closely associated with resistance and immune response, is the preferred marker gene for disease resistance research in poultry breeding. In order to explore the distribution of polymorphism in MHC B-LβⅡ(MHC class Ⅱ) gene exon 2 and the effects of its polymorphism on immune function, PCR-RFLP technique was applied to analyze the polymorphism of MHC B-LβⅡ gene exon 2 Hin1Ⅰ locus and its impact on some immune traits (lymphocyte proliferation, antibody response kinetics to Newcastle disease(ND) vaccine, concentration of Interferon-γ(IFN-γ), Interleukin-4(IL-4) and Interleukin-12(IL-12)) in 170 Liangfeng Cyan-shank partridge chickens(Gallus gallus). The results showed that two alleles (A, B) and three genotypes (AA, AB and BB) were detected by digestion of restriction endonuclease Hin1Ⅰ, and these frequencies were 0.553, 0.447 and 0.235, 0.636 and 0.129, respectively; and the lymphocyte proliferation, concentration of ND antibody, IFN-γ and IL-4 of genotype AA, AB were higher than that of genotype BB, while there were no significant differences between AA, AB and BB type in the concentration of IL-12. The results indicated that MHC B-LβⅡ gene Hin1Ⅱ locus polymorphism has a certain influence on the immune function of chicken，and it can be treated as a candidate gene for disease resistance.
