Meeting Abstract
P3.98 Monday, Jan. 6 15:30 Cephalopods Do It Differently: Insights from Neurogenomics WINTERS, GC*; KOHN, AB; STERN, N; HOCHNER, B; WALTERS, ET; DICOSMO, A; MOROZ, LL; Whitney Lab, Neuroscience Dept, UF; Whitney Lab UF; Hebrew Univ. Jerusalem; Hebrew Univ. Jerusalem; UT Houston; Univ. Naples; Whitney Lab, Neuroscience Dept, UF gabrielle.winters@gmail.com
Cephalopods (Nautilus, Loligo, Octopus, and Sepia) serve as powerful models for comparative biology. The complexity of their organizations ranges from relatively simple nervous systems in Nautilus to one of the most complex brains in Octopus. The remarkable morphological, behavioral, and physiological novelties found in cephalopods are either the result a common “genomic toolkit” that supports the development of a complex brain across taxa, novel gene/molecular mechanisms unique to the cephalopod lineage, or some combination thereof. We have sequenced neuronal transcriptomes of model cephalopods and compared them to the sequenced genome and transcriptomes of the gastropod mollusc, Aplysia californica. This approach allowed us to identify both evolutionarily conserved neuronal genes and numerous genomic innovations. We have characterized >50 neuropeptides, which are involved in locomotion, feeding, and defensive circuits. Next we localized their expression, including those that may be markers of homologous neural populations across molluscan classes. Obtained expression profiles support a hypothesis that there has been expansion of potentially homologous neural cell lineages between gastropods and cephalopods. We also found remarkable diversity in genes unique to cephalopods. This combined comparative data provides the unique opportunity to reconstruct ancestral neuronal lineages, identify specific cell homologies across species, and reveal trends in evolution within neural circuits. Our molecular resources are presented in the newly developed database of annotated neural genes, generated to test new hypotheses about the independent origin of complex brains and evolution of various developmental and neuronal systems. Supported by NSF, NIH and NASA grants to LLM
