FIG 3.

qRT-PCR analyses of the induction of srrAB and SrrAB-regulated genes in S. aureus and S. simiae upon exposure to exogenous NO·. (A) srrA transcript level analyzed via qRT-PCR and normalized to that of rpoD in wild-type (WT) S. aureus and indicated isogenic mutants in the absence of exogenous NO·; n = 3. Statistical significance was established via a one-way ANOVA with Dunnett’s posttest (***, P ≤ 0.0001). (B and C) Fold induction of indicated genes 15 min (B) or 60 min (C) following NO· exposures (administered as 10 mM DETA-NO; n = 3) relative to untreated expression levels. Expression levels were normalized to that of rpoD, and induction levels were compared between species for a given gene/time point using Student's t test using the Holm-Sidak method (***, P ≤ 0.0001; **, P ≤ 0.01; *, P ≤ 0.05).