Stochastic and Deterministic Decision in Cell Fate

From bacteria to mammals, individual cells from an isogenic population are able to assume roles resulting in phenotypic heterogeneity. The mechanisms used to make these cell fate decisions range from highly deterministic to essentially random. This wide range of behaviour springs from the interplay of intracellular molecular kinetics, the topologies of underlying gene regulator networks, epigenetic control mechanisms and cell–environment interactions. Cells utilise these factors to implement differentiation strategies such as developmental rigidity, which ensures the development of key structures in multicellular organisms, and bet hedging, the introduction of nongenetic variability to promote population fitness. Because decision-making genes in natural systems are integrated with myriad other pathways, they can be difficult to study on their own. Synthetic biology offers a means to study cell differentiation in vivo in a manner separated from normal cellular functions. Key Concepts: Gene expression is an inherently stochastic process. Despite stochastic gene expression, differentiation can proceed deterministically. Other cell fate decisions are random due to stochastic gene expression. Gene network topologies are employed to attenuate or increase the effects of noise. The field of synthetic biology is uniquely suited for exploring the complex interactions that inform cell decisions. Keywords: bet hedging; diversification; heterogeneity; motif; stochasticity; deterministic; cell fate; gene network; noise