Cell differentiation in the absence of intracellular cyclic AMP pulses in Dictyostelium discoideum

Repeated additions of cyclic AMP to a morphogenetic mutant of Dictyostelium discoideum, agip 53, induced cell differentiation to the aggregation competent state as previously reported [Darmon, Brachet, and Pereira da Silva (1975). Proc. Nat. Acad. Sci. USA72, 3163–3166]. Cyclic AMP additions elicited transient increases of the intracellular cyclic GMP concentration but no significant increases of the intracellular cyclic AMP concentration. These results suggest that transient increases of the intracellular cyclic AMP concentration are not necessary for cell differentiation. Agip 53 seems to be unable to relay cyclic AMP signals. A defect in the receptor-mediated activation of adenylate cyclase could be the biochemical basis of the mutant phenotype of agip 53.