MARLOW, H.*; MATUS, D.Q.; MARTINDALE, M.Q.; University of Hawaii at Manoa; University of Hawaii at Manoa; University of Hawaii at Manoa: Specification and patterning of the cnidarian nervous system in Nematostella vectensis

Cnidarians are among the simplest metazoans with an organized nervous system, the nerve net. The basal position of the cnidaria within the metazoa provides a potential opportunity to explore the organization and development of what may represent an ancestral metazoan nervous system. The recent publication of the genome of the anthozoan Nematostella vectensis, starlet sea anemone, allows for the focused study of the nerve net in a cnidarian. We have begun to characterize the structure of the nervous system through the use of antibody labeling of distinct populations of cells which show GABA-like, RF-amide-like, and serotonin-like immunoreactivity. Through degenerate PCR, genome and EST database searches, we have identified several cnidarian homologs to widely conserved metazoan neural patterning genes, including notch, delta, and neurogenin. Additionally, homologs of genes involved in the neuronal process guidance and formation pathway have been identified, including netrin, neuroligin, and neurexin. We will utilize the positional information acquired through immunoreactivity and in situ hybridization studies of neural makers as a reference in interpreting the development of the nervous system in the context of the identified patterning and guidance homologs. Comparison of cnidarian neural developmental patterning mechanisms to those of more complex metazoans will provide insight into the condition of the ancestral metazoan nervous system.