Expression of GFSKLYFamide-like neuropeptide in the digestive system of the sea cucumber Holothuria scabra (Echinodermata)

Abstract

Neuropeptides are key mediators of physiological processes in animals and a considerable amount of information has been accumulated on their diversity and functions across phyla. However, progress in echinoderm neurobiology has been much slower than others. The sea cucumber Holothuria scabra is an economically important tropical echinoderm species in which a neuropeptide is yet to be identified. This immunohistochemical study utilized antibody raised against GFSKLYFamide neuropeptide together with confocal laser scanning microscopy. GFSKLYFamide-like immunoreactivity was shown to be localized in the stomach and small intestines of H. scabra. This is the first report that provides evidence for the presence of GFSKLYFamide neuropeptide in the digestive tract of this species.

Keywords: GFSKLYFamide, SALMFamides, immunohistochemistry, sea cucumber, Holothuria scabra.