Inhibition of metamorphosis by RFamide neuropeptides in planula larvae of Hydractinia echinata.
The primitive nervous system in planula larvae of Hydractinia echinata (Cnidaria) has sensory neurons containing LWamide or RFamide neuropeptides. LWamides have been shown to induce metamorphosis of planula larvae into adult polyps. We report here that RFamides act antagonistically to LWamides. RFamides inhibit metamorphosis when applied to planula larvae during metamorphosis induction by treatment with LWamides (or other inducing agents such as CsCl ions, diacylglycerol and bacterial inducers). Our results show further that RFamides act downstream of LWamide release, presumably directly on target cells mediating metamorphosis. These observations support a model in which metamorphosis in H. echinata is regulated by sensory neurons secreting LWamides and RFamides in response to environmental cues.
Katsukura
Yuki
Y
Ishinomaki Senshu University, 986-8580 Ishinomaki, Japan. katsukura@zoo.uni-heidelberg.de
David
Charles N
CN
Grimmelikhuijzen
Cornelis J P
CJ
Sugiyama
Tsutomu
T
D000818:Animals; D004305:Dose-Response Relationship, Drug; D037402:Hydrozoa / Q000033:anatomy & histology / Q000187:drug effects / Q000254:growth & development*; D007447:Invertebrate Hormones / Q000494:pharmacology* / Q000502:physiology; D007700:Kinetics; D007814:Larva / Q000033:anatomy & histology / Q000187:drug effects; D008675:Metamorphosis, Biological / Q000187:drug effects; D008954:Models, Biological; D009479:Neuropeptides / Q000494:pharmacology* / Q000502:physiology
D007447:Invertebrate Hormones; D009479:Neuropeptides; C058047:arginylphenylalaninamide