With the development of comparative approaches, the present project aims to investigate the evolution of neuroendocrine systems and their role in the regulation and the plasticity of biological cycles and reproduction in marine non-conventional animal models of phylogenetic, ecological and economical relevance.
Five main animal models will be investigated: teleost fish (the European and Japanese eels Anguilla anguilla and A. Japonica respectively), two mollusks (the oyster Crassostrea gigas and the cuttlefish Sepia officinalis) and a cnidarian species (the coral Euphyllia ancora). They have been chosen in order to represent the diversity of animal life patterns with three species displaying a specific migratory behavior and two sessile species with distinct feeding processes. They also are situated at key phylogenetic positions within the animal evolutionary tree. With an ancestor present before the emergence of bilaterians, the cnidarian is at the root of this tree. The mollusks belong to the lophotrochozoans, a large clade of protostomian phyla which in contrast to its sister clade the ecdysozoans (including nematodes and arthropods) remains poorly documented in terms of functional genomics and physiology. The teleost fish, Anguilla, because, as a representative species of a basal group of teleosts (Elopomorphs), it represents a good model for studying the impact of the third round of genome duplication on gene diversity and functionality in currently living fishes.
All these organisms are environmentally sensitive species and should be considered as sentinel models to study the influence of global changes on animal physiology. They are also economically important resources either for aquaculture or fishery.
NEMO project should answer to some of the following questions.
- How diverse are the components of the neuroendocrine signaling pathways (neuropeptides and G Protein-Coupled receptors (GPCR) in metazoans?
- What is the ancestral repertoire of neuropeptides and GPCRs shared by eumetazoans?
- Are neuropeptides or GPCRs with similar sequence true orthologs?
- Do orthologous neuropeptides and GPCRs display similar spatiotemporal or stimulus / environment-dependent expression patterns?
- Are orthologous neuroendocrine components involved in the regulation of similar physiological processes?
- Do orthologous neuropeptides activate their cognate receptor with distinct mechanisms?
- Can neuropeptides with no obvious sequence similarity be considered as functional orthologs? Can these neuropeptides adopt analogous 3D structure?
- How environmental cues affect the expression of neuropeptides and GPCRs in marine species? What might be the biological consequences of these changes?