Tunability and noise dependence in differentiation dynamics

Science. 2007 Mar 23;315(5819):1716-9. doi: 10.1126/science.1137455.

Abstract

The dynamic process of differentiation depends on the architecture, quantitative parameters, and noise of underlying genetic circuits. However, it remains unclear how these elements combine to control cellular behavior. We analyzed the probabilistic and transient differentiation of Bacillus subtilis cells into the state of competence. A few key parameters independently tuned the frequency of initiation and the duration of competence episodes and allowed the circuit to access different dynamic regimes, including oscillation. Altering circuit architecture showed that the duration of competence events can be made more precise. We used an experimental method to reduce global cellular noise and showed that noise levels are correlated with frequency of differentiation events. Together, the data reveal a noise-dependent circuit that is remarkably resilient and tunable in terms of its dynamic behavior.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacillus subtilis / cytology
  • Bacillus subtilis / genetics*
  • Bacillus subtilis / metabolism
  • Bacterial Proteins / biosynthesis
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism*
  • Gene Expression
  • Genes, Bacterial
  • Isopropyl Thiogalactoside / pharmacology
  • Luminescent Proteins / biosynthesis
  • Mathematics
  • Models, Genetic
  • Models, Statistical
  • Mutation
  • Probability
  • Promoter Regions, Genetic
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*
  • Transformation, Bacterial*

Substances

  • Bacterial Proteins
  • ComS protein, Bacillus subtilis
  • Luminescent Proteins
  • Transcription Factors
  • yellow fluorescent protein, Bacteria
  • comK protein, Bacillus subtilis
  • Isopropyl Thiogalactoside