Early host gene expression responses to a Salmonella infection in the intestine of chickens with different genetic background examined with cDNA and oligonucleotide microarrays

So far the responses of chickens to Salmonella have not been studied in vivo on a whole genome-wide scale. Furthermore, the influence of the host genetic background on gene expression responses is unknown. In this study gene expression profiles in the chicken (Gallus gallus) intestine of two genetically different chicken lines were compared, 24 h after a Salmonella enteritidis inoculation in 1-day-old chicks. The two chicken lines differed in the severity of the systemic infection. For gene expression profiles, a whole genome oligonucleotide array and a cDNA microarray were used to compare both platforms. Genes upregulated in both chicken lines after the Salmonella infection had a function in the innate immune system or in wound healing. Genes regulated after the Salmonella infection in one chicken line encoded proteins involved in inflammation, or with unknown functions. In the other chicken line upregulated genes encoded proteins involved in acute phase response, the fibrinogen system, actin polymerisation, or with unknown functions. Some of the host gene responses found in this study are not described before as response to a bacterial infection in the intestine. The two chicken lines reacted with different intestinal gene responses to the Salmonella infection, implying that it is important to use chickens with different genetic background to study gene expression responses.