BP953 contains two transcriptional fusions, fha-lacZ and ptx-phoA. The results of beta-galactosidase and alkaline phosphatase enzymatic assays are shown, with w.t. values set to 100% for comparison. Also shown are the results of assays of the derivatives, BP1318, BP1324, and BP1322 harboring the bvgA alleles indicated, normalized to those for BP953. Isolation of these alleles is described in the text. Values were normalized to fha-lacZ and ptx-phoA expressed in BP953 and data from at least four assays were used in the calculation of means, standard deviations, as indicated by error bars, and statistical analysis by one-way ANOVA. Outcomes of the latter analysis are presented using the symbols: ns, P > 0.05; **, P ≤ 0.01; ***, P ≤ 0.001; ****, P ≤ 0.0001.