Submitted to: Animal Genetics
Publication Type: Peer reviewed journal
Publication Acceptance Date: 4/17/2005
Publication Date: 8/1/2005
Citation: Kim, J.W., Zhao, S.H., Uthe, J.J., Bearson, S.M., Tuggle, C.K. 2005. Physical mapping of eight pig genes whose expression level is acutely affected by Salmonella challenge. Animal Genetics. 36(4):359-62. Interpretive Summary: A major obstacle for pre-harvest food safety is the contamination of uninfected animals on the farm, during transport or in the slaughter plant environment by animals shedding pathogenic bacteria such as Salmonella. On the farm, as well as within experimental infections, the shedding of Salmonella from infected pigs varies from non-shedding to persistent shedding. Identifying the pig genes that respond to Salmonella infection is important to determine the mechanisms involved in swine resistance (and susceptibility) to Salmonella. Eight pig genes were chromosomally mapped that respond to Salmonella enterica serovar Choleraesuis infection by changing their gene expression. Two of these genes are specifically noteworthy, SDCBP and CXCL10. These two genes were mapped to locations within chromosomes that have previously described traits associated with them. SDCBP maps within a region linked to porcine immunity and CXCL10 maps to a region involved in regulating the quantity of porcine lymphocytes following mixing and transport of pigs. Characterizing the genetic loci of swine genes involved in the response to infection with Salmonella Choleraesuis may assist in the development of diagnostic assays, identify methods to control shedding of Salmonella from infected pigs as well as characterize genetic markers to identify Salmonella-resistant lines of pigs, thereby improving the health status of breeder herds and protecting our food supply.
Technical Abstract: Eight swine genes whose RNA levels respond to Salmonella infection within 48 hours of inoculation were mapped using both the porcine somatic cell hybrid panel (SCHP) and the INRA-Minnesota Porcine Radiation Hybrid (IMpRH) panel. DNAJA4 was mapped to SSC7q12-q23 corresponding to HSA15q25.1, HSP90 was located on SSC7q26 (HSA14q32.33), HSP105 was mapped to SSC11p13 (HSA13q12.3), CXCR4 was located on SSC15q12-q14 (HSA4q21), CXCL10 was mapped to SSC8q11-q12 (HSA4q21), SDCBP was mapped to SSC4q15-q16 (HSA8q12), ANXA5 was localized to SSC8q23-q27 (HSA4q26-q28), and GNB2L1 was mapped to SSC2q21-q24 (HSA5q35.3). Retention frequencies of markers on the IMpRH panel ranged from 23% to 38% (average 32%) and LOD scores ranged from 5.77 to 18.43 (average 10.8). These localizations can now be combined with QTL data to include or exclude these genes as positional expression candidate genes to improve disease resistance in pigs. SDCBP and CXCL10 are such candidates, as they map within known QTL peaks for mitogen-induced proliferation and lymphocyte number, respectively, as reported by Edfors-Lilja and colleagues.