Meeting Abstract

122.2  Monday, Jan. 7  Histamine functions and distribution in gastrulation and skeletogenesis of the sea urchin S. purpuratus NGUYEN, J; HEYLAND, A*; University of Guelph, Guelph aheyland@uoguelph.ca

Earlier studies established a novel function of histamine signaling (HA) in metamorphic competence of the sea urchin Strongylocentrotus purpuratus. Preliminary results suggests that several neuron like cells synthesize HA also in gastrulation and pluteus formation. Here we tested the distribution and function of this important neurotransmitter in gastrulation and skeletogenesis. Our data show that HA is required for proper gastrulation in sea urchin embryos based on the inhibition of histamine receptor protein. Furthermore our data suggest that neuron like cells in the region of the developing apical ganglion produce HA post-gastrulation. When we tested a previously proposed link between HA and programmed cell death (PCD) we found that PCD is not required for gastrulation and HA does not appear to regulate this process in early embryogenesis. Our data further emphasize the importance of HA as a signaling molecule in sea urchin development and suggest that paracrine signaling may play an important role in sea urchin gastrulation in addition to transcriptional regulation.