Meeting Abstract
P3.97 Thursday, Jan. 6 Genome-wide Characterization of Signaling Peptides Across Animal Phyla and Parallel Evolution of Neural Systems CITARELLA, M. R.*; KOHN, A.B.; BOBKOVA, E.; YU, F.; MOROZ, L.L.; Whitney Lab for Marine Bioscience; Whitney Lab for Marine Bioscience; Whitney Lab for Marine Bioscience; ICBR; Dept, Neuroscience, Univ. of Florida mcitarel@cise.ufl.edu
Neuropeptides and protein hormones are ancient signaling molecules involved in many activities of neural circuits, plasticity and development. Here, we provide a systematic survey of these molecules across major animal lineages (Ctenophores, Placozoa, Cnidarians as basal metazoans; Arthropods and Nematodes as Ecdysozoans; Annelids, Molluscs and Phoronids as Lophotrochozoans; Chordates, Hemichordates, Echinoderms and Xenoturbella as Deuterostomes). Most of our data from molluscs and selected arthropods, phoronids, Xenoturbella, Acoela and ctenophores is original. We started with Aplysia, where we identified more than 120 prohormones including 56 previously unknown candidates. Then, using deep transcriptome profiling (454/Roche pyrosequencing) from multiple neuronal tissues and developmental stages, we expanded the analysis to 12 other molluscs and representatives of other phyla. We validated neuron-specific expression of more than 80 predicted peptides using in situ hybridization. We also identified several hundred prohormone homologs with varying degrees of evolutionary conservation. Finally, we have developed NeuroBase, a comparative neurogenomics database for discovery of signaling and neuronal specific molecules. When combined, these genome-wide comparative surveys provide the unique opportunity to reconstruct of ancestral neuronal lineages, identify cell homologies across species and reveal trends in evolution within neural circuits. However, the majority of neuropeptides appear to be class and phylum-specific ligands suggesting that these intercellular messengers are among the most evolutionarily dynamic signaling molecules, demonstrating a high degree of parallel evolution and apparently independent origins across animal phyla.
