Echinoderms: San Francisco, Mooi& Tellord(eds)© 1998Balkema, Rotterdam, ISBN 90 5410 929 7 Presence of the SALMFamide neuropeptides S 1 and S2 in the britdestar Amphipholis squamata: Immunohistochemical and radioimmunoassay detection .\ /\ - N. De Bremaeker, J. Mallefet & F. Baguet Laboratory of Animal Physiology, Catholic University ofLomain, Belgium M.C.Thomdyke & D.J.Potton Department of Biology, Royal Holloway University of London, UK D.Deheyn Laboratory of Marine Biology, University of Brussels, Belgium Recendy a novel faimly of echinoderm ACKNOWLEDGEMENTS: neuropepddes, the SALMFamides, has been characterized. Sl and S2 were isolated from radial This work was supported by a cooperation grant nerve cords of the starfishes Asterias rubens and CGRI-British Council-FNRS. Financial support Asteriasforbesi (Hphick et al. 1991). S3 and S4 from FDS (UCL) and FRFC (number 6.231.85), were isolated and sequenced from extracts of the Contribution of the "Centre Interuniversitaire de digestive system of the sea cucumba" Holothuna Biologie Marine" (CIBIM). gCabemma (Diaz-Miranda et al. 1992). immunocytochemistry and radio-immunoassay studies have shown'Sl and S2 to be widely REFERENCES distributed in the nervous systems of asteroids, echinoids, and ophiuroids. Physiological Cobb J.L.S. & Stubbs T.R. 1981. The giant experiment, have shown that the neuropepddes neuron system in ophiuroids. I. The general Sl and S2 have neuromodulating effects on the morphology of the radial nerve cords and the luminescence of Amphipholis squamata, a. smaU circumoral nerve ring. Cell Tissue Res., 219, 197-207. cosmopolitan ophiuroid (Mallefet et <d. 1994). Sl and S2 at 10-9 M and 10-10 M, respectively, Deheyn D., Alva V. & Jangoux M. 1996. Fine potentiate the acetylcholine-induced luimnescence. structure of the photogenous areas in the The aim of this work was to detect the bioluminescent ophiuroid Amphipholis presence of Sl and S2_ in_A, squamata by squamata (Echinodermata, Ophiuridea). immunohistochemistry and radioimmunoassay; Zoomorphology 116: 195-204^ The nervous system of A. squamata consists Diaz-Mirahda L., Price D.A., Greenberg M.J., of radial nerve cords that run ventrally along all Lee T.D., Dobble K.E. & Garcia-Arraras J.E. two novel arms. The radial nerve cords of the five arms are 1992. Characterization of from the sea cucumber interconnected by the circumoral nerve ring neuropeptides (Deheyn et al. 1996). Each radial nerve cord and Holothuria glaberrima. Biol. Bull. 182:241- the circumoral nerve ring are composed of two 247. ElphickM-R., Price D.A^ Lee Y. & Thomdyke superimposed nerve plexuses, the ectoneural M.C. 1991. The SALMFamides: a new famUy plexus Mid the hyponeural plexus. In this study, Sl-like immunorractivity was detected in _ both of neuropq)ddes isolated from an echinoderm. Proc. RSoc. Land. B. 243:121-127. plexuses of the brachial nerve cord and Ae circumoral ring. S2-Ute immunoreactivity was Ghyoot M., Cobb J.L.S. & Thomdyke M.C. 1991. Localizadon of neuropeptides m the only wealdy detected in the ectoneural plexus of the'brachiaf radial nerve cord and the circumoral nervous system of the brittle star Ophium nerve ring. The immuno-reactivily patten ophiura. Phil. Trans. R. Soc. Land. B. observed iii the radial nerve cord of one arm 346:433-444. MaUefetJ.,DeBremaekerN. & Baguet F. 1994. segment is_identical to that of the adjacent arm Neuromodulatory effects ofGABA, Sl_ & 82, segment. Such segmental oiganization of the PMRFamide and ANTHO-RFamideon nearve cord was reported previously by Cobb and Stubbs (1981) and Ghyootetal. (1994). Amphipholis squamata (Echinodermata) The radioimmunoassay results _from acetone luminescence. In: A.K. Campbell, L.J.Kricka extracts of A. squamata showed 0.006 pmojes of & P.E. Stanley (eds.), Bioluminescence and Sl/mg wet weight and 0.025 pmoles of S2/mg chemi-luminescence: 109-112. J. WUey & Sons, Chichester. wet weight. It is interesting to note that there seems to be a seasonal variation in Sl and S2 . concentrations. 343.