FIG. 1.

Relative expression levels of whiB1 to whiB7 during various phases of growth. Total RNA was isolated from M. tuberculosis (CDC1551) cultures grown to the OD₆₀₀ values shown. The OD₆₀₀ values for the respective growth phases are as follows: early exponential (0.22), mid-late exponential (0.8 to 0.91), early stationary (1.9), late stationary (3.0), and very late stationary (2 days or 5 days after OD₆₀₀ reaches 3.0). Real-time quantitative real-time RT-PCR was performed, and the relative expression level of each whiB was calculated using the sigA transcript for normalization for RNA amounts and the expression level at an OD₆₀₀ of 0.22 as a control. Data shown are averages from four independent experiments.