FIG. 8.

Growth curves and changes in gene expression of genes that are negatively regulated by BvgAS and maximally expressed when the BvgAS system is inactive for B. bronchiseptica strain RB54, a Bvg⁻ phase-locked mutant. (A) Optical densities (OD₆₀₀), DNA concentrations (geq/ml), and CFU counts (CFU/ml) during growth of RB50 are plotted along the y axis, and time, given in hours, is plotted along the x axis. All data points represent averages obtained from triplicate cultures. (B) Change in gene expression (y axis) occurring at 6-h intervals (x axis) starting at early logarithmic phase (12 h) and continuing until late stationary phase (48 h) determined by using qRT-PCR. Data shown are averages obtained from triplicate cultures. The error bars represent standard deviations.