<p>β-galactosidase activity of <i>V</i>. <i>cholerae</i> strains with chromosomal, translational fusions of <i>E</i>. <i>coli lacZ</i> to the <i>gbpA</i> 5’ UTR with wild type Vc1, Vc1<sup>G12T</sup>, or Vc1<sup>A39T</sup>, with transcription initiation under the control of the constitutive P<sub><i>lacUV5</i></sub> promoter: PlacUV5-Vc1UTR-<i>lacZ</i>, PlacUV5-Vc1UTR<sup>G12T</sup>-<i>lacZ</i>, PlacUV5-Vc1UTR<sup>A39T</sup>-<i>lacZ</i>, respectively [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0148478#pone.0148478.ref038" target="_blank">38</a>]. Each reporter strain carried pPDE and was grown without arabinose (wild-type c-di-GMP level; white bars) or with 0.2% arabinose (reduced c-di-GMP; black bars). (B) Dose response analysis using the P<sub><i>lacUV5</i></sub>-Vc1UTR-<i>lacZ</i> reporter strain, with vector or pPDE, grown in rich medium with a range of arabinose concentrations. Increasing PDE production corresponds with decreasing intracellular c-di-GMP. (A and B) Measurements of β-galactosidase activity were done with at least three independent biological samples, and the means and standard error are shown. * <i>P</i> < 0.05, *** <i>P</i> < 0.001, n.s. = not significant by one-way ANOVA and Bonferroni’s multiple comparison test.</p
