This application is for support of the 11th International Spores Conference, to be held at Woods Hole, Mass., May 9-13, 1992. 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 was seen and studied as a primitive form of cell differentiation. The emphasis of the present conference is the regulation of expression of genes that control the sporulation. The program is designed to convey a picture of the whole process of differentiation of 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 will bring together leading scientists from around the world, and will highlight exciting recent developments. The format of the conference is designed to maximize interaction among participants.