NEWS AND VIEWS Winner takes all in a race for cell fate

The choice between alternative cell fates is fundamental to biology. The Gram-positive soil bacterium Bacillus subtilis can become competent for genetic transformation by external DNA or can form resistant spores. Although decades of work has elucidated much about the complex regulatory pathways that lead to these mutually exclusive fates (Dubnau and Losick, 2006), the decision mechanism that determines whether a cell becomes competent or forms spores has remained elusive. The paper by Kuchina et al (2011a), recently published atMolecular Systems Biology, asks the following question of this ‘simple’ prokaryotic system. Is there cross talk between the pathways that gradually diminishes the probability of one fate while enhancing that of the other? Or is decision making the result of a ‘molecular race ’ in which the pathways proceed indepen-dently until one or another fate wins out by chance