FIG 4.

Relative gene expression ratios in the Clostridium botulinum ATCC 3502 parent and sigF, sigE, and sigG mutant strains with sense-oriented ClosTron insertions over 24 h of growth for spo0A (A and B), sigF (C and D), sigE (E and F), sigG (G and H), and sigK (I and J). Bar charts (A, C, E, G, and I) show differences in relative transcript levels between parent and mutant strains at individual time points (*, P < 0.05). Line charts (B, D, F, H, and J) show the trend in gene expression for each gene expressed in each strain. Expression ratios were normalized to 16S rrn expression and calibrated to the parent strain expression levels at the 5-h time point to compare mutant and parent expression ratios. Error bars represent maximum and minimum expression values from three replicates.