Regensburg 2016 – scientific programme
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DY: Fachverband Dynamik und Statistische Physik
DY 38: Statistical Physics of Biological Systems II (Joint Session with DY)
DY 38.3: Talk
Wednesday, March 9, 2016, 12:00–12:15, H43
Evolutionary emergence of phenotype switching — Pintu Patra1,2 and •Stefan Klumpp1,3 — 1Max-Planck-Institut für Kolloid- und Grenzflächenforschung, Potsdam, Germany — 2Rice University, Houston, Texas, USA — 3Institut für Nichtlineare Dynamik, Universität Göttingen, Göttingen, Germany
Bacterial persistence (phenotypic tolerance to antibiotics) provides a prime example of bet-hedging, where normally growing cells generate slow-growing but antibiotic-tolerant persister cells to survive through periods of exposure to antibiotics. The population dynamics of persistence is explained by a phenotype switching mechanism that allows individual cells to switch between these different cellular states with different environmental sensitivities. We report a theoretical study based on an exact solution for the case of a periodic variation of the environment to address how phenotype switching emerges and under what conditions switching is or is not beneficial for long-time growth [1]. Specifically we report a bifurcation through which a fitness maximum and minimum emerge above a threshold in the duration of exposure to the antibiotic. Only above this threshold, the optimal phenotype switching rates are adjusted to the time scales of the environment, as emphasized by previous theoretical studies, while below the threshold a non-switching population is fitter than a switching one. Whether the transition is continuous or discontinuous depends on how the phenotype switching rates are allowed to vary. [1] P. Patra and S. Klumpp, Phys. Biol. 12, 046004.