The soil bacterium Bacillus subtilis can become "competent"--it can take up genetic material from its surroundings. Competence is regulated by the protein ComK, which controls the genes responsible for DNA uptake. However, cells can only transition to competence in a random fashion during a limited period of time at the beginning of the stationary phase of growth. Maamar et al. (see the Perspective by Mettetal and van Oudenaarden) now find that temporal regulation of comK transcription defines the "window of opportunity" during which cells can become competent, and intrinsic noise in gene expression controls the rate at which stochastic transitions to the competent state occur.
H. Maamar, A. Raj, D. Dubnau, Noise in gene expression determines cell fate in Bacillus subtilis. Science 317, 526-529 (2007). [Abstract] [Full Text]
J. T. Mettetal, A. van Oudenaarden, Necessary noise. Science 317, 463-464 (2007). [Summary] [Full Text]
