Abstract
Sporogenesis of Bacilli represents a kind of development in prokaryotes, cytodifferentiation, which is brought about by a stepwise activation of 40-50 loci scattered on the bacterial chromosome (1,2). These loci are probably some kind of "spore genes" or "spore operons" coding for enzymes and structural or regulatory proteins involved in sporogenesis.
Inactivation of such a spore locus inhibits further steps in spore development. Knowledge of the control of the expression of individual spore loci is thus important for an understanding of the principles of developmental regulation in prokaryotes.
The exocellular proteolytic enzymes of Bacillus subtilis such as the serine proteinase, represent a group of enzymes, whose synthesis is somehow related to sporogenesis though they do not participate directly in this process .