Stochastic gene expression and regulatory networks

Abstract

Genetically identical cells exposed to the same environmental conditions can show significant variation in molecular content and marked differences in phenotypic characteristics. This intrinsic variability is linked to the fact that many cellular events at the genetic level involve small numbers of molecules (low copy numbers). Although stochastic gene expression was originally viewed as having detrimental effects on cellular function, with various implications for disease, it is now seen as being potentially advantageous. For example, intrinsic noise can provide the flexibility needed by cells to adapt to fluctuating environments or respond to sudden stresses, and can also support a mechanism by which population heterogeneity is established during cell differentiation and development.