Stochastic analysis of toggle switch and toxin-antitoxin modules

Regulation processes in cells are performed by networks of interacting genes, which regulate each other's expression. To analyze the function of genetic networks, we simulate the dynamics of small functional modules using stochastic methods which take into account the effects of fluctuations. In this talk I will consider two genetic modules - the toggle switch (encoded synthetically on plasmids) and the toxin-antitoxin system (I will focus on the hipBA module in E. coli). I will show that in such modules, which include feedback, fluctuations give rise to crucial quantitative and qualitative effects. For the toggle switch I will show how the details of the system architecture affect the bistable state and the switching time. For the hipBA toxin-antitoxin system, I will focus on its role in the phenomenon of bacterial persistence.