IMMUNOHISTOCHEMICAL LOCALIZATION OF A SHAKER-RELATED VOLTAGE-GATED POTASSIUM CHANNEL PROTEIN IN SCHISTOSOMA-MANSONI (TREMATODA, DIGENEA)

We have recently isolated a cDNA (SKV1.1) encoding a Shakei-related K channel from the human parasitic trematode Schistosoma mansoni. In or der to better understand the functions of SKv1.1 protein, the distribu tion of SKv1.1 protein in adult S. mansoni was analyzed by immunohisto chemistry using a region-specific antibody. SKV1.1 proteins were widel y expressed in the nervous and muscular systems. The strongest immunor eactivity (IR) was observed in the nervous system of both male and fem ale. In the nervous system, IR for SKv1.1 proteins was localized in ce ll bodies and nerve fibers of the anterior ganglia, the central commis sure, and the main nerve cords. IR was also observed in the dorsal and the ventral peripheral nerve nets, fine nerve fibers entering into a variety of structures such as the dorsal tubercles, longitudinal and v entral muscle fibers, and oral and ventral suckers. In the muscular sy stem, SKv1.1 proteins were localized to the longitudinal, circular, an d ventral muscle fibers of male as well as in isolated muscle fibers w here native A-type K+ currents were measured. Moderate IR was also see n in a large number of cell bodies in the parenchyma. These results in dicate that SKv1.1 protein may play an important role in the regulatio n of the excitability of neurons and muscle cells of S. mansoni. (C) 1 995 Academic Press, Inc.