Role of cAMP in the release from dormancy of freshwater sponge gemmules.

The role of 3′5′-cyclic AMP (cAMP) in the release from dormancy of gemmules from the freshwater sponge Spongilla lacustris was investigated. During the first 2 hr of germination a significant decrease in the gemmule cAMP content was observed. In the presence of amino-phylline, at concentrations which inhibit the gemmule-cAMP-phosphodiesterase, the cAMP content did not decrease and germination was arrested at a stage prior to nuclear separation and cell division. The findings suggest that inhibition of cell division by cAMP participates in the control of dormancy.