Figure 3. | A long-term epigenetic memory switch controls bacterial virulence bimodality

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A long-term epigenetic memory switch controls bacterial virulence bimodality

Figure 3.

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The Hebrew University of Jerusalem, Israel
Figure 3.
Download figureOpen in new tabFigure 3. Model and measurements of bimodal switching rates.

(A) Scheme and equations of a bimodal switching model. The two morphotypes, BIG and SMALL, are characterized by different growth rates, µB and µS, respectively, and different switching rates a and b. Note that these parameters depend on growth conditions. (B) Measurement and fit to the analytical solution of equations Equations 1 and 2 during exponential growth under activating conditions with initial conditions B(t = 0)=1, S(t = 0)=0, see Materials and methods-Mathematical model. Green and red lines are ScanLag measurements of the SMALL and BIG morphotype fractions, respectively (means ± s.d. of three independent biological replicates). Solid lines are the fit to data using Equations 1 and 2, resulting in a = 0.24 ± 0.13 h−1 and b<<a under activating conditions. These switching rates result in a population dominated by the SMALL morphotype after a few hours. Note that stationary phase caused resetting of the culture to the BIG morphotype. (C) Model (solid line) and experimental measurement (dotted line and markers) of the growth of the total population for the data presented in (B).