Mathematics and Computer Science, Volume 2

12Resource Allocation Determines Alternate Cell Fate in Bistable Genetic Switch

Priya Chakraborty and Sayantari Ghosh^⋆

Department of Physics, National Institute of Technology Durgapur, Durgapur, West Bengal, India

Abstract

Living cells need a constant availability of certain resources to have a sustained gene expression process. Limited availability of cellular resources for gene expression, like ribosomes and RNA Polymerase, significantly modifies the system dynamics. Factors like the variation in rate of binding or variation in efficiency of the recruited resource have the potential to affect crucial dynamic phenomena like cell fate determination. In this paper we have taken a very important motif, a bistable genetic toggle switch, and explored the effect of resource imbalance in this circuit in terms of the bifurcations taking place. We show that initial asymmetric biasing to resources via resource affinity or gene copy number significantly modifies the cell fate transition, both in pitchfork and saddle node type bifurcation. Our study establishes that in a limited resource environment, controlled resource allocation can be an important factor for robust functioning of the synthetic or cellular genetic switches.

Keywords: Gene regulation, resource allocation, cell fate decision, pitchfork bifurcation, saddle node bifurcation, genetic toggle switch

12.1 Introduction

Proteins that govern all functionalities in a living cell are produced by two major steps: transcription and ...