Identification of synaptophysin-like immunoreactivity in the sea anemone Condylactis gigantea (Cnidaria: Anthozoa).

Synaptophysin is a membrane protein of synaptic vesicles that serves as an antigenic marker for nervous and endocrine systems in mammals. Monoclonal antisera generated against synaptophysin were used for immunocytochemical staining in tissues of the tentacles of the sea anemone Condylactis gigantea (Cnidaria: Anthozoa). Specific staining, visible at the light and electron microscope levels, was found in the tentacle. Proteins were extracted from the tissues and solubilized. Using SDS-polyacrylamide gel electrophoresis and Western blotting, we identified proteins with apparent molecular weights of 38,000, 78,000, and 114,000. The data suggest the tissues of this anthozoan contain synaptophysin-like proteins with molecular properties similar to those of mammalian neurons.