FIG 6.

CodY integrates cell density and nutritional signals. Cultures of strains UAMS-1 (A), MS-1 (ΔcodY) (B), and CM18 (Δagr) (C) were harvested at 180 min of growth in TSB medium (late-exponential phase), filtered, and used to resuspend exponential-phase cells of strain UAMS-1 or MS-1 (ΔcodY) at an initial A₆₀₀ of 0.05. Samples of the latter cultures were harvested at 60, 90, 120, and 180 min of growth in the culture fluids, RNA samples were prepared, and relative levels of RNAIII were determined by real-time quantitative PCR. For each target gene, the ratio of the transcript to 16S rRNA was normalized to the corresponding ratio obtained for wild-type cell RNA harvested at 60 min of growth in culture fluid from Δagr cells. The data represent the results of two biological replicates. Error bars correspond to the standard errors of the means.