Figure 1.

Glucose induction of ywlE-lacZ and increase in cellular Mn concentrations. (A) and (C) β-Galactosidase activities were measured by using highly sensitive substrate CPRG shown in Miller units. Means from three independent experiments and the SDs are shown. Significant differences in the effects of glucose addition at T2 were determined using nonpaired t test. ∗p < 0.05; NS, no significant differences. The x-axis represents the growth time in hours relative to the end of vegetative growth (T0). Cells were grown in sporulation medium with (closed symbols) or without (open symbols) 2% glucose and sampled hourly. Strains: WT (OAM888), and derivatives of OAM888, mneP (OAM1004), mntH/mntA (OAM1003), mntR (OAM1007), and ahrC (OAM1006). (B) left: relevant structure of OAM888. Box, bent arrows, and stem–loop show ORF, promoter, and terminator, respectively. Right: flow of glucose-mediated regulation of ahrC. Dotted arrow and T-bar mean indirect activation and direct inhibition, respectively. SR1, small regulatory RNA, inhibits translation of ahrC. (D) cellular Mn concentrations. T2 cells grown in sporulation medium were harvested and processed. Strains; WT (168), mneP (OAM993), mntH/mntA (OAM992), mntR (OAM996), and ahrC (OAM995). “Glu” represents glucose. Three biologically independent samples were measured. Significant differences between Wt and mutants, with or without glucose (∗ and “NS” above each data point indicate p < 0.05 and no significant difference, respectively) and the effect of glucose addition to each strain were determined using nonpaired t test. ∗p < 0.05; NS, no significant differences. The short horizontal lines indicate the mean of the data points. CPRG, chlorophenolred β-D-galactopyranoside.