Upon nutrient starvation, B. subtilis differentiates into a dormant cell type called a spore. The first landmark event in this process is an asymmetric division generating a large mother cell and smaller forespore (the prospective spore). Shortly after division the mother cell membrane migrate around the forespore in a phagocytic-like process called engulfment. At this stage the mother nurtures the developing spore while the spore prepares for dormancy. Once the spore is mature, the mother lyses releasing it into the environment. We study how the mother and forespore communicate with each other during this developmental process. We are also investigating the molecular mechanisms underlying the morphological process of engulfment and the organization and segregation of the chromosome during differentiation.