Shu-Hong Zhao

Gene expression profiling in Salmonella Choleraesuis-infected porcine lung using a long oligonucleotide microarray

Understanding the transcriptional response to pathogenic bacterial infection within food animals is of fundamental and applied interest. To determine the transcriptional response to Salmonella enterica serovar Choleraesuis (SC) infection, a 13,297-oligonucleotide swine array was used to analyze RNA from control, 24-h postinoculation (hpi), and 48-hpi porcine lung tissue from pigs infected with SC. In total, 57 genes showed differential expression (p < 0.001; false discovery rate = 12%). Quantitative real-time PCR (qRT-PCR) of 61 genes was used to confirm the microarray results and to identify pathways responding to infection. Of the 33 genes identified by microarray analysis as differentially expressed, 23 were confirmed by qRT-PCR results. A novel finding was that two transglutaminase family genes (TGM1 and TGM3) showed dramatic increases in expression postinoculation; combined with several other apoptotic genes, they indicated the induction of apoptotic pathways during SC infection. A predominant T helper 1-type immune response occurred during infection, with interferon γ (IFNG) significantly increased at 48 hpi. Genes induced by IFNs (GBP1, GBP2, C1S, C1R, MHC2TA, PSMB8, TAP1, TAP2) showed increased expression during porcine lung infection. These data represent the first thorough investigation of gene regulation pathways that control an important porcine respiratory and foodborne bacterial infection.

Assignment of the scavenger receptor class B, member 2 gene (SCARB2) to porcine chromosome 8q11-->q12 by somatic cell and radiation hybrid panel mapping.

The identifi cation of genes controlling infectious disease is an important step towards increasing disease resistance in the pig. Infectious diseases increase the cost of production (Wegener et al., 2003), and, for zoonotic pathogens, also impact food safety (Beloeil et al., 2004). Disease resistance has genetic heritability, and the mapping of genes involved in natural resistance (innate immunity) has been reported (Tuggle et al., 1997; Sun et al., 1998). Quantitative trait loci (QTLs) for immune parameters (Edfors-Lilja et al., 1998) and immune capacity traits have been reported (Edfors-Lilja et al., 2000). The objective of this research was to map a gene identifi ed as having altered gene expression patterns within the mesenteric lymph nodes of swine during infection with Salmonella enterica serotype Choleraesuis. The SCARB2 gene has been shown to increase RNA expression within 24 h postinfection, and was identifi ed using Suppression Subtractive Hybridization (SSH) (Uthe et al., manuscript in preparation). Overall, this gene is an excellent candidate for participating