Fig 4. Dispersal patterns in the ΔcheY, ΔlapG, and ΔrbmB mutants.

(A) Cartoon depiction of the proposed roles of CheY, LapG, and RbmB in V. cholerae biofilm dispersal. (B) Change in total biovolume (cellular volume inside a biofilm) of individual biofilms for the indicated strains over time based on spinning-disc confocal z-stacks. The data for each biofilm are normalized as fold-change relative to the biovolume at the first time point. N = 5 biological replicates. (C) Left panel: representative kymograph of dispersal data from a ΔcheY replicate, depicting the change in local density at 10-min intervals and at the indicated distances from the biofilm core. Black line represents the biofilm boundary. Middle panel: as in the left panel for a model of random cell departures. Right panel: centroids of the density changes from the experimental data and the model of random cell departures over time. Lines and shading represent means and standard deviations for N = 5 biofilms, respectively; (D) as in C for the ΔlapG mutant; (E) as in C for the ΔrbmB mutant. (F) Quantification of the radial components of the displacements during the dispersal phase for the indicated strains. Crossbars represent means and dots represent individual replicates for N = 5 biofilms, with the radial displacements averaged over each replicate biofilm. P = 0.054, 0.030, and 0.048 based on two-sided unpaired t tests of the ΔcheY, ΔlapG, and ΔrbmB data relative to the wild-type data, respectively. (G) Quantification of dynamic region volume fraction during the dispersal phase for the indicated strains. Data represent averages over the entire dispersal phase. Crossbars represent means and dots represent individual replicates for N = 5 biofilms. P = 0.291, 0.094, and 0.072 based on two-sided unpaired t tests of the ΔcheY, ΔlapG, and ΔrbmB data relative to the wild-type data, respectively. a.u., arbitrary units. *P < 0.05; n.s., P > 0.05. Underlying data for this figure can be found on Figshare (https://figshare.com/s/e0978ade2bc95dccf357).