| Abstract: | Adenosine 3′,5′-cyclic monophosphate (cAMP) and guanosine 3′,5′-cyclic monophosphate (cGMP) were detected at concentrations of 8–11 and 10–20 pmol · mg?1 protein, respectively, in zoospores of a brown alga, Undaria pinnatifida (Harvey) Suringer. Cellular levels of these cyclic nucleotides did not substantially change during dark to light transition. cAMP-stimulated protein phosphorylation was found in soluble cell-free extracts of zoospores of Undaria pinnatifida and Laminaria angustata Kjellman. |
