S9-12 Sunday, Jan. 6 15:00 - 15:30 In Sickness and in Health: The Role of Innate Immunity in the Regulation of Cnidarian-Dinoflagellate Mutualisms WEIS, Virginia M; Oregon State University email@example.com http://weis.science.oregonstate.edu/
Corals engage in a mutualistic symbiosis with intracellular photosynthetic dinoflagellates. This intimate partnership forms the trophic and structural foundation of coral reef ecosystems. This presentation will examine the cellular and molecular mechanisms underlying the establishment, maintenance and breakdown of the symbiosis in coral- and anemone-dinoflagellate partnerships. Host innate immunity and symbiont strategies for modulating this immune response are central to the stability of the symbiosis. During onset and maintenance of symbiosis these mechanisms include lectin-glycan signaling, upregulation of the immunosuppressive TGF-beta pathway and changes in the sphingolipid rheostat and complement pathway. Coral bleaching, a severe threat to the health of reefs worldwide, is caused by global warming and results from dysbiosis: the collapse of the symbiosis. Studies suggest that coral bleaching is a host innate immune response to a compromised and stressed symbiont. This evidence includes increased nitric oxide levels, and host cell apoptosis and autophagy in heat-stressed animals, all well-known immune mechanisms in other systems to eliminate detrimental microbial invaders. Finally, I will discuss the international effort to rapidly develop a sea anemone model system to advance genetic techniques and new tools for the field to help save severally threatened corals.