Construction Of SSH Library Of Broilers Fed With Bacillus Cereus And Screening And Identification Of Immune-related Genes

To explore the molecular mechanism of the effect of Bacillus cereus PAS38 on the immunity of broilers,60 7-day-old broilers were divided into two groups.The control group was fed with basal diet,and the treatment group was fed with basal diet containing Bacillus cereus PAS38 1×10~6 CFU/g.Six broilers were randomly selected from each group at the age of 42 days;and the spleen,thymus and bursa of fabricius were dissected.SSH technology was used to construct differential gene library,GO annotation was carried out on the library,and immune related differential genes were screened.Finally,siRNA technology was used to interfere with the expression of some differential genes in lymphocytes of broiler,and the mRNA expression levels of six cytokines,IL-1B,IL-2,IL-6,My D88,IRF1,and TLR4 were detected,and the function of the differential genes was preliminarily analyzed.The results are as follows:1.The SSH libraries of spleen,thymus and bursa of fabricius included 119,250 and 214differentially expressed genes,respectively.2.The SSH libraries of spleen,thymus and bursa of fabricius were screened to 9,26 and21 immune-related differential genes,respectively.3.Nine genes were selected from the spleen,thymus and bursa of fabricius immune-related differential genes for absolute q PCR,respectively.And 92.59%of them significantly changed in gene copies(P<0.05).4.Seven differentially expressed genes(JCHAIN、FTH1、IGF1R、PRDX1、CD3E、TLR7 and CDK6)in lymphocytes of broiler were interfered by siRNA.Compared with the negative siRNA control group and the blank control group,the copies of the 7 different genes were highly significantly reduced after the corresponding siRNA interference(P<0.01).5.When the seven differential genes(JCHAIN、FTH1、IGF1R、PRDX1、CD3E、TLR7and CDK6)were interfered in lymphocytes,some cytokines were significantly down regulated(P<0.05).The results showed that after feeding broilers with Bacillus cereus PAS38,it could affect the expression of many genes in their immune organs.And Bacillus cereus PAS38 might up-regulate certain genes in immune organs of broilers,such as growth promoting factors IGF1R and CDK6;genes related to antigen recognition and intracellular signal transduction(PRDX1,TLR7 and CD3E);and genes related to the production of immunoglobulin and cy-tokines(JCHAIN and FTH1);to promote the development of immune organs,lymphocytes proliferation,cytokine secretion,so as to regulate the immune of broilers.