Presence of GFSKLYFamide-like neuropeptide in the nervous tissue of Holothuria scabra: Immunohistochemical evidence

BACKGROUND: Physiological activities in animals and other biological systems are often regulated by neuropeptides. GFSKLYFamide neuropeptide, an echinoderm SALMFamide, was first isolated from the sea cucumber, Holothuria glaberrima, an echinoderm, in 1992 (Díaz-Miranda et al., 1992). Since this discovery, there have been unresolved questions regarding the interphyletic and intraphyletic distribution of GFSKLYFamide neuropeptide. AIM: The study was done in an attempt to answer these questions. MATERIALS AND METHODS: An immunohistochemical study was conducted on the radial nerve cord of Holothuria scabra utilizing an antibody specifically raised against GFSKLYFamide. RESULTS: Results show strong and widespread localization of GFSKLYFamide immunoreactivity, including the ectoneural and hyponeural regions of the radial nerve cord. CONCLUSION: This, to the best of our knowledge, is the fi rst report that provides evidence for the presence of GFSKLYFamide-like neuropeptide in the nervous tissue of this species.