The role of the sporulation gene spoIIIE in the regulation of prespore-specific gene expression in Bacillus subtilis.

The spoIIIG gene encodes a sigma factor that determines prespore-specific gene expression during sporulation in Bacillus subtilis. Correct spatial and temporal expression of the spoIIIG gene depends on a number of other sporulation (spo) genes, but only one of these genes, spoIIIE, has a specific effect on spoIIIG expression and not on gene expression in the other differentiating cell, the mother cell. However, the spoIIIE gene is expressed predominantly before differentiation begins. Thus, its product must play an important role in sensing or determining the spatial localization of prespore-specific gene expression in this system.