Sporulation delay by stable cAMP analogues in the slime moldPhysarum polycephalum.

Plasmodial cells of the slime moldPhysarum polycephalum become competent for sporulation following a prolonged period of starvation in darkness. Then sporulation can be induced by illumination. Microinjections of the stable (Sp)- and (Rp)-diastereoisomers of adenosine cyclic 3',5' monothionophosphate before and during a sensitive period from the start of illumination until 5 h after lead to a significant delay in the sporulation process.Both of the diastereoisomers of cyclic AMP prolong the time for sporangia to form in darkness. However, the (Sp)-diastereoisomer is more effective and causes morphological changes in plasmodia.The experimental data suggest that cyclic AMP is decisively involved in light-induced differentiation in the lower eukaryotoPhysarum polycephalum.