Figure 5. Phenotypic variability is tuned by additional copies of components of the σ^V circuit.

• A
  Schematic of genetic perturbations to σ^V circuit. Second copies of σ^V components were added under the control of the P _sigV promoter. ? = P _sigV‐sigV (2xsigV), P _sigV ‐sigVrsiV (2xsigV‐rsiV) or P _sigV‐rsiV (2xrsiV).
• B
  Model simulations predict that the 2xsigV or 2xsigV‐rsiV strains have a homogenous σ^V response to lysozyme, while the 2xrsiV strain has increased heterogeneity. Bars correspond to mean (N = 999 simulations) ± s.d. (1,000 bootstraps).
• C
  As predicted, the 2xsigV or 2xsigV‐rsiV strains have a homogenous σ^V response to 1 µg/ml lysozyme, while the 2xrsiV strain has increased heterogeneity. Each bar plot is the average of three biological repeats. The bars correspond to the mean ± s.d.

Data information: For both (B) and (C), bars represent the fraction of cells that have activated σ^V 30 min after treatment with lysozyme. σ^V activated cells were defined as those cells that had passed a threshold of the WT mean before lysozyme application plus six standard deviations. For more information on the number of repeats, please see Appendix Table S3.