Cell individuality: the bistability of competence development

Heterogeneous development of competence among cells of the bacterium Bacillus subtilis provides an appealing model of cell individuality, an area that is currently attracting considerable research interest. Under appropriate conditions, only a fraction of cells in an isogenic culture become competent for transformation. Two experimental studies have now pinpointed the same auto-stimulatory feedback loop of gene expression as the principal requirement for the establishment of this 'bistable' response.