Genetics: Published Articles Ahead of Print, published on July 29, 2007 as 10.1534/genetics.107.075523 1 Molecular genetic analysis of two loci (Ity2 and Ity3) involved in the host response to infection with Salmonella Typhimurium using congenic mice and expression profiling Vanessa Sancho-Shimizu*,†, Rabia Khan*,†, Serge Mostowy†, Line Larivière†, Rosalie Wilkinson†, Noémie Riendeau†, Marcel Behr†, Danielle Malo*,†,‡ * Department of Human Genetics, McGill University, Montreal, QC, Canada † Center for the Study of Host Resistance, McGill University Health Center, Montreal, QC, Canada ‡ Department of Medicine, McGill University, Montreal, QC, Canada 2 Running Title: Genetics of MOLF Salmonella Susceptibility Keywords: Salmonella susceptibility, wild-derived inbred mice, gene expression, congenics, QTL fine mapping Corresponding Author: Danielle Malo 1650 Cedar Avenue, room L11-144, Montreal, QC, Canada H3G 1A4 1-514-934-1934 (tel) 1-514-934-8238 (fax)
[email protected] 3 ABSTRACT Numerous genes have been identified to date that contribute to the host response to systemic Salmonella Typhimurium infection in mice. We have previously identified two loci, Ity2 and Ity3, that control survival to Salmonella infection in the wild-derived inbred MOLF/Ei mouse using a (C57BL/6J X MOLF/Ei)F2 cross. We validated the existence of these two loci by creating congenic mice carrying each QTL in isolation. Subcongenic mice generated for each locus allowed us to define the critical intervals underlying Ity2 and Ity3. Furthermore, expression profiling was carried out with the aim of identifying differentially expressed genes within the critical intervals as potential candidate genes. Genome wide expression arrays were used to interrogate expression differences in the Ity2 congenics, leading to the identification of a new candidate gene (Havcr2).