Winner takes all in a race for cell fate

Mol Syst Biol. 7: 558The 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 at Molecular 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 independently until one or another fate wins out by chance?Spore formation is dependent on a phosphorylated transcription factor, Spo0A‐P (hereafter OA‐P), which is known to gradually increase in average concentration as cells approach the decision to sporulate (Fujita and Losick, 2005). Indeed, this gradual increase is essential for …