The extraordinary resistance of bacterial spores, the diversity of sporeforming species, and the importance (good and bad) of sporeformers to medicine, to food processing and to agriculture were major stimuli for early research on spore formation. Increasingly, spore formation has been seen and studied as a primitive form of cell differentiation. The emphasis of the present conference is regulation of expression of genes that control sporulation. The program is designed to convey a picture of the whole process of differentiation for a vegetative bacterium into a spore, and to relate spore formation to other post- exponential stress responses. One session will be devoted to the related process of vegetative cell division. The conference which will convene in Woods Hole, Massachusetts on May 9-13, 1992, will bring together leading scientists from around the world, and will highlight exciting recent developments. The formats of the conference is designed to maximize interaction among participants.