Abstract: 【Objective】 Genome-wide association studies were performed by using the chicken 60k high density SNP array for nine immune traits in Beijing-You chicken and identification of candidate genes and loci responsible for these traits were identified. Here, by treating Beijing-You chicken with polyinosinic acid-polycytidylic acid, Poly(I:C) and Salmonella enteritidis (SE), several candidate genes were further studied based on authors’ GWAS result, including CD1b, BMA1(B locus M alpha chain 1), TRIM27 (tripartite motif-containing 27) and ZNF692(zinc finger protein 692). 【Method】 Eighty 12-d-old Beijing-You Chickens were divided into three groups: the control group, Poly(I:C) treatment and SE treatment groups. All the experimental birds were reared in isolated facility. The treatment groups were, respectively, injected intramuscularly into the breast with 0.5 mL of Poly(I:C) and SE bacterial suspension containing 108 CFU and the control group was given 0.5 mL saline. Chickens were sacrificed at 12 h, 24 h, 3 and 6 days of post infection (DPI). Blood samples were collected and serum was stored. The bursa of Fabricius, thymus and spleen were rapidly removed to test inflammatory factors and gene expression. 【Result】 The weight was significantly lower than control group 24 h post infection (P＜0.01) and temperature of chickens was significantly changed in 24 h after treatments. In serum, concentrations of IFN-α, IL-4 and IL-6 were significantly higher than the control and reached a peak at 24 h or 3 d (P＜0.01). TNF-α increased in all periods and significantly higher than the control group after 3 days. The expression of candidate gene CD1b was not tissue-specific, but BMA1, TRIM27 and ZNF692 were highly expressed in thymus and bursa fabricius. In thymus, the expression of CD1b was significantly different between two treatments at 12 h and 24 h post infection. When treated with SE, the expression of CD1b was significantly increased and reached a peak at 24 h (P＜0.01). The mRNA expression of BMA1 was significantly different between two treatment groups in 12 h and 3 d post infection, when treated with Poly(I:C), the expression at 12 h post infection was lower than the SE group, but it was significantly higher than SE group (P＜0.01). The expression of TRIM27 on 6 DPI in Poly(I:C) treatment was significantly higher than control group, expression of ZNF692 was not different among three groups. In bursa of Fabricius, the expression of CD1b was the highest at 12 h after infection. There were no differences in the expression of genes BMA1 and TRIM27 between two treatments. The expression of ZNF692 was higher on 1 DPI in SE treatment than Poly(I:C), and also the highest on 3 DPI in both groups. 【Conclusion】 CD1b, BMA1,TRIM27 and ZNF692 might be involved in the immune response after treating with S. enteritidis and Poly(I:C). CD1b gene had an important role in the early stage of SE infections. BMA1 and ZNF692 were involved in immune response of thymus and bursa.

Key words: CD1b , BMA1 , TRIM27 , ZNF692 , mRNA expression , chickens