Splenic Gene Expression Profiling in White Leghorn Layer Inoculated with the Salmonella enteritidis

Salmonella Enteritidis is a food-borne pathogen; which can cause great threat to human health through the contaminated poultry products. To systematically understanding the molecular mechanisms of S. Enteritidis infection in poultry, twenty-week old S. Enteritidis negative White Leghorn were selected and randomly divided into two groups, one group of 60 chickens was inoculated with S. Enteritidis, the other group of 40 chickens was mock inoculated with PBS used as control group. Spleen samples were collected for RNA isolation on 8 and 16 days post-inoculation (dpi), respectively. Two samples in each group were randomly selected to make a RNA pool, and 4 RNA pools were made from each group. Sixteen RNA pools were made in total for gene expression analysis. The gene expression profiling was analyzed by Agilent 4×44K microarray experiment with balance design. The results showed that there were 1,371 differentially expressed genes on 8 dpi, which included 682 up-regulated and 689 down-regulated ones, 692 differentially expressed genes were observed on 16 dpi, which included 373 up-regulated and 319 down-regulated genes. DAVID was used for GO and PATHWAY analysis for the differentially expressed genes in each comparison. The immune related GO terms were significantly enriched which included endotoxin of signal transduction, leukocyte adhesion, G protein coupled receptor proteins. The signaling pathways, such as the cell cycle, the ligand of stimulating nerve tissue, the biosynthesis of steroid hormone, cell adhesion molecules, retinol metabolism were also significantly enriched. The results herein will deepen the understanding of the molecular mechanism of chicken response to salmonella infection in early laying stage.