Experiment
C57BL/6J mice are resistant and A/J mice are susceptible to Staphylococcus aureus infection. The authors used CSS (chromosome substitution strains) from these backgrounds to localize the chromosomal regions responsible to the susceptibility observed. .CSS mice with mouse chromosome 8, 11 or 18 from the susceptible background (A/J) transferred
individually into the otherwise resistant background (C57BL/6J). Mouse chromosome 18 showed a significant association with the resistant and susceptible phenotype.
To fine map the chromosome 18 loci involved in determining susceptibility to Staphylococcus aureus infection the authors performed a QTL analysis generating N2 backcross mice by mating (AJ x C57BL/6J)F1 mice to C57BL/6J mice. A total of
144 N2 backcrossmice were generated and infected with Staphylococcus aureus, and their survival times were measured. Two QTL were identified with one at a peak between D18Mit178 and D18Mit124 (Sstapa1 )and another between D18Mit122 and D18Mit184(Sstapa2).
A total of 10 genes (March3, Cep120, Chmp1b, Dcp2, Dtwd2, Isoc1, Lman1, Spire1, Tnfaip8, and Seh1l) mapping within Sstapa1 and Sstapa2 QTL were differentially expressed between Staphylococcus aureus infected A/J and C57BL/6J mice.
Analysis Tools