Weis 9728405 Symbiotic associations between two or more unrelated organisms are found throughout every ecosystem. These relationships encompass a spectrum of lifestyles, from mutualistic to parasitic, and from extracellular to intracellular. Among the most significant marine mutualisms are those between corals and their algal symbionts, which together form the foundation of the entire coral reef ecosystem. A great deal is known about corals on a macroscale level, such as their global distribution and ecology. However, microscale processes of inter-partner communication and regulation that occur during the initiation, establishment and maintenance of these symbioses remain largely unexplored. A lack of basic knowledge of these processes has hampered efforts to understand the global phenomenon of coral bleaching, which is the result of the breakdown of the symbiosis. Widespread bleaching, which leads to coral death and reef degradation, is considered a serious environmental threat. This study will take a multileveled approach to the examination of the initial events surrounding the onset of symbiosis between corals and their symbiotic algae. The PIs will examine when and how the symbiosis is established during the natural life cycle of corals. Secondly, the PIs will investigate the effects that the establishment of the partnership has on the biochemistry and molecular biology of the host coral.
