Bistability, epigenetics, and bet-hedging in bacteria

Annu Rev Microbiol. 2008;62:193-210. doi: 10.1146/annurev.micro.62.081307.163002.


Clonal populations of microbial cells often show a high degree of phenotypic variability under homogeneous conditions. Stochastic fluctuations in the cellular components that determine cellular states can cause two distinct subpopulations, a property called bistability. Phenotypic heterogeneity can be readily obtained by interlinking multiple gene regulatory pathways, effectively resulting in a genetic logic-AND gate. Although switching between states can occur within the cells' lifetime, cells can also pass their cellular state over to the next generation by a mechanism known as epigenetic inheritance and thus perpetuate the phenotypic state. Importantly, heterogeneous populations can demonstrate increased fitness compared with homogeneous populations. This suggests that microbial cells employ bet-hedging strategies to maximize survival. Here, we discuss the possible roles of interlinked bistable networks, epigenetic inheritance, and bet-hedging in bacteria.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Bacillus subtilis / genetics
  • Bacillus subtilis / physiology
  • Bacteria / genetics*
  • Biofilms / growth & development
  • Biotechnology
  • Epigenesis, Genetic*
  • Escherichia coli / genetics
  • Escherichia coli / physiology
  • Gene Regulatory Networks
  • Genomic Instability
  • Lac Operon
  • Models, Genetic
  • Phenotype
  • Spores, Bacterial / genetics
  • Transformation, Genetic