HEYLAND, Andreas*; MOROZ, Leonid/L; The Whitney Laboratory for Marine Bioscience and Department of Neuroscience, University of Florida, FL; The Whitney Laboratory for Marine Bioscience and Department of Neuroscience, University of Florida, FL: A Search for Pro-Neuronal Genes: Understanding basal animals without brains

Neurons or secretory cells with neuron-like organization might appear in evolution independently in multiple lineages. Genes linked to signaling, hormonal and neurotransmitter pathways and patterning of intercellular connections most likely existed before the appearance of morphologically defined neurons and were co-opted for these specific functions in specialized neurons. The placozoan Trichoplax adherens is a basal metazoan with no nervous system but specific traceable behaviors. It only contains four cell types, some of which have neuron-like properties. Using tubulin, actin and specific neuronal markers we analyzed these different cell types as candidates for pro-neuronal cells. Moreover we performed BrdU staining to search for progenitors of putative neurons and stem cells. High throughput sequencing in the form of EST (expressed sequence tags) collection and microchemical analyses suggest furthermore that Trichoplax has a very different inventory of signaling molecules than other metazoa.