EAGER: Development of a Model System for Study of Dinoflagellate-Cnidarian Symbiosis

Stanford University, Stanford CA

Investigators

Abstract

In the U.S. and around the world, coral reefs are of enormous ecological and economic importance for biodiversity preservation, shoreline protection, food production, drug discovery, and recreation. Unfortunately, coral reefs have shown extensive and increasing degradation in recent years, apparently due largely to the inability of the corals to survive the stresses imposed by increasing ocean temperature, acidity, and pollution. Coral death is typically preceded by "bleaching", in which the coral animals lose the symbiotic algae that normally live inside their cells and provide them with most (often >90%) of their energy through photosynthesis. There has been much recent attention to this problem from marine and conservation biologists, but their efforts have been severely handicapped by the lack of basic information about the molecular and cellular mechanisms that underlie coral growth and the interactions between the animal hosts and their algal symbionts. This gap is due largely to the fact that corals themselves present multiple significant difficulties for laboratory study. In other areas of biological and biomedical research, progress has come primarily from intensive studies of a small number of "model organisms" that were chosen not for their intrinsic interest, but instead for their susceptibility to intensive experimental investigation, including the application of powerful genetic methods for investigation of cell function. This project focuses on developing the small sea anemone Aiptasia as a model system for the study of coral molecular and cell biology. Aiptasia is closely related to corals and is symbiotic with similar or identical types of algae, but it has many great experimental advantages. The specific studies proposed here build on recent progress in the PI's laboratory (notably the induction of spawning and production of larvae in the laboratory) and focus on three different aspects of developing genetic methods for this system, namely (1) methods for following natural and induced variation in genetic crosses, (2) methods for obtaining RNA-mediated knockdown of gene expression, and (3) methods for transforming animals with DNA constructs that will allow disruption or tagging of individual genes. Progress with these methods should have a major impact on investigations of basic coral biology and will be communicated to the research community through presentations at conferences, publications, and both laboratory-specific and community-maintained websites. In the process, both postdoctoral and predoctoral students will receive a diverse and sophisticated training to prepare them for independent careers in research and/or policy. In addition, the intrinsic fascination of the complex and beautiful coral-reef ecosystem will provide numerous opportunities for effective outreach to both younger students and the general public on both coral-specific and more general issues of basic science and its relationship to conservation.