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 traitswere 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, includingCD1b,BMA1(B locus M alpha chain 1),TRIM27 (tripartite motif-containing 27) andZNF692(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-αincreased in all periods and significantly higher than the control group after 3 days. The expression of candidate geneCD1b was not tissue-specific, butBMA1,TRIM27 andZNF692 were highly expressed in thymus and bursa fabricius. In thymus, the expression of CD1bwas 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 ofBMA1 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 ofTRIM27 on 6 DPI in Poly(I:C) treatment was significantly higher than control group, expression ofZNF692 was not different among three groups. In bursa of Fabricius, the expression ofCD1b was the highest at 12 h after infection. There were no differences in the expression of genesBMA1 andTRIM27 between two treatments. The expression ofZNF692 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 andZNF692 might be involved in the immune response after treating withS. enteritidis and Poly(I:C).CD1b gene had an important role in the early stage ofSE infections.BMA1 andZNF692 were involved in immune response of thymus and bursa.%【目的】利用高密度SNP芯片完成了对北京油鸡血清免疫球蛋白Y含量等9个免疫性状的关联分析，筛选得到了与性状显著关联位点和候选基因。基于该研究结果，以集中分布在16号染色体的候选基因CD1b、 BMA1（B locus M alpha chain 1）、TRIM27（tripartite motif-containing 27）和ZNF692（zinc finger protein 692）作为研究对象，以北京油鸡为实验材料，在聚肌胞（Polyinosinic acid-polycytidylic acid, Poly I：C）和细菌的处理下进一步对候选基因表达特性进行分析和鉴定。【方法】随机选取80只12日龄北京油鸡分为3组：空白对照组、聚肌胞处理组和肠炎沙门氏菌（Salmonella enteritidis, SE）处理组，分别饲养在独立的隔离器内。两处理组分别胸肌注射聚肌胞注射液和SE菌液，对照组注射生理盐水，于处理后12 h、24 h、3 d和6 d（days post infection, DPI）检测血清炎症因子的变化水平和候选基因表达规律。【结果】经过聚肌胞和SE处理后，体重在24 h之后显著低于空白组（P＜0.05），体温24 h以内显著升高；血清IFN-α、IL-4和IL-6水平先升高后降低，在第24小时或第3天达到峰值，TNF-α水平持续升高，3 d后极显著高于空白组（P＜0.01）。两种处理条件下CD1b的mRNA表达没有组织特异性，其他3个基因在胸腺和法氏囊中高表达。在胸腺组织中，CD1b在两处理间12和24 h的表达量存在显著差异（P＜0.01），在聚肌胞处理组整个感染阶段没有显著性变化，在SE组是先升高后降低的趋势，感染后24 h时表达量最高（P＜0.01）；BMA1在12 h和3 d时两处理组间差异显著，聚肌胞处理组在12 h时表达量低于SE处理组，而在3 d时显著高于SE处理组（P＜0.01）；TRIM27在聚肌胞感染6 d时表达量显著高于空白组（P＜0.05），ZNF692的表达量在3组间没有差异。在法氏囊中，CD1b表达量在两个处理组中存在差异，在SE组12 h时表达量高；BMA1和TRIM27的表达量在两组间没有差异，TRIM27在3 d时表达量最高（P＜0.01），ZNF692在SE组感染24 h时相对表达量高于聚肌胞处理组，在两组中都在3 d时表达最高。【结论】CD1b、BMA1、TRIM27和ZNF692参与了聚肌胞和肠炎沙门氏菌引起的免疫反应过程，是与免疫相关的功能基因；CD1b主要在肠炎沙门氏菌感染的前期发挥作用；BMA1和ZNF692分别参与胸腺和法氏囊的免疫反应。
展开▼
