Nutritional limitation can trigger elaborate developmental responses in many microorganisms culminating in the formation of spores that can remain dormant for many years. Sporulation is an energy-intensive process that is not easily reversed and is initiated in response to only the harshest environments. In the June 20 Sciencexpress, José E. González-Pastor and colleagues at the Harvard University show that in Bacillus subtilis (the model sporulating Gram-positive bacteria), cells at the beginning of the sporulation pathway may delay entering the dormant phase by killing their siblings and feeding on the released nutrients (Sciencexpress, DOI:10.1126/science.1086462, June 20, 2003).

González-Pastor et al. generated B. subtilis mutants in which the genes controlled by Spo0A, a protein that regulates sporulation, had been altered. They identified two operons strongly induced at the start of sporulation and in which mutations accelerated spore formation. The first operon, termed skf (sporulation killing factor), is a group...