Single Nucleotide Polymorphism Of The IL-1β Gene And Correlation With Some Immune Traits In Three Chicken Breeds

Rugao Chicken (RG) , Wenchang Chicken (WC) and Anka Chicken(AK) were used for this research. Respectively, the value of Heterophil/Lymphocyte(H/L) , SRBC antibody titer, ND antibody titer, AI antibody titer and the IL-1 concentration in blood serum at different days of age were detected. Meanwhile, four pairs of primer were designed as the sequence of IL-1βof red jungle fowls, and the SNP site were detected via PCR-SSCP. Then, the correlation was analysed between polymorphic sites and immune traits detected at 56 days of age.The result of immune traits showed as below: (1) the difference of H/L value existed between different breeds in the same days of age, but it became smaller along with time. RG's H/L value changed less than the other breeds, however, WC and AK had obvious change from high to low level. (2) The SRBC antibody titer of three breeds got the highest at 56 days, in which, the value of WC were the highest while that of AK was the lowest(P<0.05). Moreover, there were significant differences between them. The sensitivities to different dosages of breeds were different except RG. (3) ND antibody titer of three breeds had the same change, but the extent of change were different, though the AK's antibody titer was in the midst of RG and WC before the third immunity, the antibody titer of AK was extremely significantly higher than the other two breeds of chicken after that period (P<0.01). There were insignificant difference of AI antibody titer between RG and WC in all test time except 56 day, meanwhile antibody titer of AK was extremely significantly lower than that of the other two breeds in all test time(P<0.001).(4) The IL-1 concentration in blood serum of AK was extremely significantly higher than RG(P<0.01) and WC(P<0.001), while there was no significant difference between RG and WC. The result showes that Chinese chicken breeds had some more advantages than outside breeds on disease resistance.The result of detecting SNP site showed as follows: There were 15 SNP sites in IL-1 were detected in all three breeds, and only 482 and 1507 sites of them were only found mutation genotype existing. And there were differences of genotype distribution between three breeds at the other 13 sites. Respectively mutation at 107, 241 and 893 sites of WC did not accord with Hardy-Weinberg using a chi-square goodness of-fit test, as well as mutation at 130 site of RG. So, we can descry that the SNP sites of the gene have relation with production traits or disease resistance, that these sites were impact by selection.Then, the correlation was analysed between polymorphic sites and immune traits, and there were totally 10 sites had relation with some immune traits. And the 241 site has relation with the value of H/L, SRBC antibody titer and AI antibody titer, and 107 site has relation with the ND antibody titer and AI antibody titer, meanwhile, 1215 site has relation with the ND antibody titer and IL-1 concentration in blood serum. And the other 7 sites has relation with one of the immune traits. So, all the three sites of 107, 241 and 1215 could be a genetic marker in breeding of disease resistance.The best genotype group performed better on immune traits which contain H/L value, SRBC antibody titer, ND antibody titer and AI antibody titer than the best genotype. This result show that we can do better on selecting for new breed via genotype group than genotype at single site.