Fig. 6: VadR controls cell curvature during biofilm development.

a Relative activity of the vadR promoter during biofilm growth of wild-type V. cholerae cells. In each cell the fluorescence of mRuby2, expressed from the vadR promoter was normalized by the signal of the constitutive Ptac-promoter-driven sfGFP-fluorescence signal. Heatmap shows vadR promoter activity at both spatial (distance from surface of biofilm representing height of the biofilm) and temporal (time of biofilm growth) resolution. Subset of images show the cells from two time points and separate locations of the biofilm. These cells were rendered by ParaView⁵⁶ after final segmentation and analysis using BiofilmQ⁵⁵. The color of each cell represents the activity of the vadR promoter. b Spatio-temporal heatmap showing cell curvature of each cell for V. cholerae biofilms. Cell curvature of individual cells was calculated using BiofilmQ⁵⁵. To calculate the cell curvature of each cell inside the biofilms, similar positions of the biofilm as in a were selected for rendering. In these subset of images, the color represents the cell curvature of each cell. c A correlation graph was plotted for vadR promoter activity as function of cell curvature. Calculation of vadR promoter activity and cell curvature was done for V. cholerae wild-type biofilms grown in flow chambers. Each point represents the mean ± SEM of >1000 cells for given time point in a biofilm. d Model showing the regulatory functions of the VadR sRNA in V. cholerae. Expression of vadR sRNA is controlled by the VxrAB two-component system. The sRNA regulates multiple biological processes, including cell shape and biofilm formation. Source data underlying panels a–c are provided as a Source Data file.