Many cnidarians, including corals, anemones, and jellyfish, contain photosynthetic algae that supply them with critical nutrients. Habitat changes associated with human activity can destabilize this symbiotic relationship, leading to a rapid rise in recent coral bleaching events. These bleaching events often have devastating effects on reef ecosystems, which are amongst the biodiverse communities on the planet. Although there is increasing evidence that the bacterial and fungal microbiome has an important role in the physiology of healthy animals, relatively little is known about the microbiome of cnidarians or the role of their microbiome in mediating cnidarian-algae symbiosis. This research project will systematically examine the microorganisms associated with cnidarians, the compounds these microbes produce, and the effects these compounds have on cnidarian physiology and symbiosis. The results from these experiments will provide key insights into cnidarian biology, which is urgently needed for the design and implementation of global preservation efforts. Furthermore, this research is likely to yield general insights into animal-microorganism relationships, since cnidarians are one of the oldest animal lineages and provide an important evolutionary perspective, the diversity of cnidarians allows comparative approaches, and the strong interactions in this system will expose general principles. In addition, this project has a strong education and public outreach component, including a teacher’s workshop to bring new lab-based curriculum to local public-school districts.
The symbiotic relationship between cnidarians and phototrophic dinoflagellates (family Symbiodiniaceae) has a critical role in cnidarian physiology. Recent findings suggest that both the cnidarian host and the symbiotic dinoflagellates are associated with complex bacterial and fungal microbiomes. However, little is known about the diversity of these communities, their secondary metabolome, or how they affect cnidarian physiology and cnidarian-dinoflagellate symbiosis. The proposed research will address this knowledge gap by using metagenomics to describe the cnidarian-associated microbial communities, comparative metabolomics analysis to identify compounds produced by both the host animal and microbes, and in vivo assays to determine the effects of microbes and metabolites on cnidarian physiology. The first aim of this project will identify the effects of the microbiome on coral-algae symbiosis using the anemone Exaiptasia. This research will describe the bacterial and fungal diversity in the host, the effects of microbiome manipulation on coral bleaching, the metabolome of symbiotic and aposymbiotic hosts, and the effects of metabolites from cultured microbes. The second aim of this project will determine the effects of the microbiome on coral development and symbiosis using the upside-down jellyfish Cassiopea. Life cycle transitions in this jellyfish are dependent on the presence of symbiotic dinoflagellates, and this project will identify the bacterial and fungal community in Cassiopea, the metabolome of different life cycles, and the effects of the microbiome on animal development.
This project is jointly supported by the NSF Understanding the Rules of Life (URoL) Big Idea initiative and the Chemistry of Life Processes (CLP) Program in the Division of Chemistry at NSF.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
