CYCLIC-AMP AND THE REPRODUCTIVE PROCESS OF THE SCALLOP ARGOPECTEN PURPURATUS

The level of cyclic AMP was measured in both female and male gonadal p ortions of the functionally hermaphrodite scallop Argopecten purpuratu s. Measurements were done during both processes of spawning and gonada l recovery. To study the spawning process, samples were analyzed, befo re stimulation, when animals looked stimulated (with enlarged white go noducts), during the release of sperm, during the release of oocytes, and 24 hours after the end of spawning. Before the stimulus, the cAMP values were higher in the male gonadal portion than in the female port ion. After applying the stimulus no change was detected in the female portion until oocytes were released; at this moment a sharp increase i n cAMP level was detected. In the male portion of the gonad, the nucle otide level decreased sharply after applying the stimulus and returned to prestimulus values when oocytes were released. For the study durin g the gonadal recovery period, samples were taken on days 2, 6, 10, 14 , 18, 22, and 26 after spawning. In both gonadal portions, the levels of cAMP showed an initial decrease, then an increase in the middle of the study period and a sharp decrease when the process of gonad restor ation was being completed. Dopamine and serotonin increased the levels of the nucleotide in the female gonadal portion only in the middle of the gonad restoration period. The results suggest that cAMP is involv ed in the regulation of the different stages of the reproductive proce ss of this scallop by mechanisms that may involve the phosphorylation of different kinds of proteins for each stage. (C) 1997 Wiley-Liss, In c.