Departmental Papers (MEAM)

Document Type

Conference Paper

Subject Area


Date of this Version

December 2006


Copyright 2006 IEEE. Reprinted from Proceedings of the 45th IEEE Conference on Decision & Control 2006.

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This paper focuses on the lactose regulation system in Escherichia coli bacteria, one of the most extensively studied examples of positive feedback in a naturally occurring gene network. State-of-the-art nonlinear dynamical system models predict a bi-stability phenomenon that is confirmed in experiments. However, such deterministic models fail to explain experimental observations of spontaneous transition between the two stable states in the system and the simultaneous occurrence of both steady states in a population of cells. In this paper, we propose a stochastic model that explains this phenomenon. Furthermore, we also extract a coarser two-state continuous-time Markov chain as a higher level abstraction of this model, and show that macroscopic properties are retained in the abstraction.



Date Posted: 30 May 2008

This document has been peer reviewed.