Effect of csrS and csrR mutations on expression of CsrRS-regulated genes in GAS strain 854 under standard growth conditions.

Strain designations: TM, 854csrSTM; csrSΩ, 854csrSΩ; H280A, 854csrSH280A; H280A TM, 854csrSH280A,TM; csrR, 854ΔcsrR.aTranscript abundance for 854 csrS and csrR mutant strains grown to early exponential phase in unsupplemented THY medium relative to that in wild type strain 854. Expression of hasB, spyCEP, mac, and SPy0170 was quantified by qRT-PCR. Values represent mean ratios ± SEM of three independent experiments performed in triplicate.bExpression level of the four genes is significantly different (P