Mapping Data

Experiment

• Experiment
  TEXT-Congenic
• Chromosome
  11
• Reference
  J:237460 Yan Q, et al., Dusp3 and Psme3 are associated with murine susceptibility to Staphylococcus aureus infection and human sepsis. PLoS Pathog. 2014 Jun;10(6):e1004149
• ID
  MGI:5901735

Genes

Gene	Assay Type
Sstapa3	PCR amplification
Dusp3
Psme3

Notes

• Experiment
  Staphylococcus aureus (S.aureus) is an important cause of potentially lethal human infections. The current study sought to identify the genetic determinants of susceptibility to S. aureus using susceptible A/J mice vs. resistant C57BL/6J mice.
  
  Reciprocal crosses between CSS C57BL/6J-Chr11^A/J mice and C57BL/6J mice were used to generate an F1 population with heterozygous Chromosome 11. F1 mice were then intercrossed to generate 208 F2 progeny for QTL mapping.
  
  For murine peritonitis-sepsis experiments eight week old male mice in each strain, C57BL/6J, A/J and C57BL/6J-Chr11^A/J, were injected with 10⁷ CFU/g S.aureus (Sanger 476) or 2x10⁵ CFU/g E.coli (K1H7) and observed every 6 hours for morbidity continuously for 5 days. For murine intravenous sepsis 8 week old male mice in each strain, C57BL/6J, A/J and C57BL/6J-Chr11^A/J, were injected with 2x10⁶ CFU/g S.aureus (Sanger 476) and observed every 6 hours for morbidity continuously for 3 days. For bacterial load quantification, kidneys were collected from euthanized mice 24 hours post infection.
  
  To localize the determinants on A/J Chromosome 11 that were responsible for susceptibility to S.aureus infection QTL analysis was performed. Twelve polymorphic microsatellite markers between A/J and C57BL/6J, with an average inter-marker distance of 3.1 cM covering Chr 11, were selected and genotyped for all 208 F2 intercrossed mice by PCR amplification and gel electrophoresis. J/qtl software was used to analyze phenotype and genotype data for linkage of survival time after infection with S.aureus Sanger 476 and marker location. Phenotypes were defined as either sensitive or resistant based on survival data. Linkage analysis results were expressed as LOD scores. The LOD score was considered significant if >=3.55 (p=0.05) and suggestive if >=1.6 (p=0.63). Threshold values for linkage were determined by 1,000 permutation test using J/qtl.
  
  One QTL was identified significantly linked to susceptibility, Sstapa3 (Susceptibility to Staphylococcus aureus infection 3), mapped to Chromosome 11 between flanking markers D11Mit67 and D11Mit334 with a LOD= 5.0, p=0.05. [Fig 1.D.] The QTL region contained 422 genes.
  
  Murine microarray expression data was used to further identify candidate genes within the QTL region. Genes that were differentially expressed between the susceptible A/J and resistant C57BL/6J strains at all pre-infection and post-infection time points were considered. A total of 11 genes met the criteria: Eif1, Cnp, Fam134c, Cntd1, Psme3, Dusp3, Mpp2, Slc4a1, Slc25a39, Dcaf7 and Gna13.
  
  Whole genome transcription profiling identified five genes (Dcaf7, Dusp3, Fam134c, Psme3, and Slc4a1) that were significantly differentially expressed in a) S. aureus infected susceptible (A/J) vs. resistant (C57BL/6J) mice and b) humans with S. aureus blood stream infection vs. healthy subjects. Three of these genes (Dcaf7, Dusp3, and Psme3) were down-regulated in susceptible vs. resistant mice at both pre- and post-infection time points by qPCR. siRNA-mediated knockdown of Dusp3 and Psme3 induced significant increases of cytokine production in S. aureus-challenged RAW264.7 macrophages and bone marrow derived macrophages (BMDMs) through enhancing NF-kB signaling activity. Similar increases in cytokine production and NF-kB activity were also seen in BMDMs from C57BL/6J-Chr11^A/J but not C57BL/6J. These findings suggest that Dusp3 and Psme3 contribute to S. aureus infection susceptibility in A/J mice and play a role in human S. aureus infection.