Our laboratory studies development in the spore-forming bacterium Bacillus subtilis. B. subtilis undergoes an elaborate cycle of cellular differentiation that culminates in the formation of a dormant cell type, the spore. Spore formation involves the transformation of a vegetative cell into a two-compartment sporangium by asymmetric division. The compartments receive an identical chromosome yet have dissimilar developmental fates involving differential expression of distinct sets of genes. We seek to elucidate the entire regulatory circuit that governs entry into sporulation, cell-specific gene expression, and the linkage of gene expression to landmark events in morphogenesis. Other aspects of B. subtilis biology of interest are the role of stochasticity in cell-fate decision making and the formation of architecturally complex communities of cells known as biofilms. We also investigate biofilm formation in the pathogen Staphylococcus aureus.