English

Genetic Toggle Switch in the Absence of Cooperative Binding: Exact Results

Molecular Networks 2015-11-18 v2 Statistical Mechanics

Abstract

We present an analytical treatment of a genetic switch model consisting of two mutually inhibiting genes operating without cooperative binding of the corresponding transcription factors. Previous studies have numerically shown that these systems can exhibit bimodal dynamics without possessing two stable fixed points at the deterministic level. We analytically show that bimodality is induced by the noise and find the critical repression strength that controls a transition between the bimodal and non-bimodal regimes. We also identify characteristic polynomial scaling laws of the mean switching time between bimodal states. These results, independent of the model under study, reveal essential differences between these systems and systems with cooperative binding, where there is no critical threshold for bimodality and the mean switching time scales exponentially with the system size.

Keywords

Cite

@article{arxiv.1506.05583,
  title  = {Genetic Toggle Switch in the Absence of Cooperative Binding: Exact Results},
  author = {Tommaso Biancalani and Michael Assaf},
  journal= {arXiv preprint arXiv:1506.05583},
  year   = {2015}
}

Comments

12 pages, 4 figures. To appear in Phys. Rev. Lett. (2015)