Gene regulating terminal differentiation:
AcrA gene product ACB is intracellular adenylyl cyclase abundant during late slug and culmination stages, generating cAMP pool that elevates PKA activity driving terminal differentiation of prespore into mature spores and prestalk into stalk cells. Mutants lacking ACB exhibit defective sporulation, fragile stalks, and inability to maintain PKA-dependent gene expression after migration. ACA dominates earlier aggregation signaling, ACG senses osmolarity for germination, smlA regulates counting factor abundance, making them unsuitable for terminal differentiation control. ACB therefore integrates developmental cues ensuring irreversible commitment after motile phase, coupling metabolic state to morphogenetic completion and spore encapsulation processes.
Ref: Developmental Biology, ACB adenylyl cyclase AcrA in terminal differentiation - PKA control of spore maturation.