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Coral Viral Ecology
My current research heavily focuses on viruses as agents of disease on coral reefs. I am expanding this aspect of my work quite considerably, trying to define the prevalence of herpes-like viruses in corals from around the world as well as investigating the role of dinoflagellate viruses on host-symbiont (zooxathellae) interactions. Recently, I have identified a full length viral genome, similar to either a Geminivirus or a Nanovirus, which is elevated in corals in response to nutrients. This elevation is coincident with dinoflagellate abundance, suggesting that this virus may infect coral symbionts. Zooxanthellae dinoflagellate expulsion has been the major cause of coral reef bleaching world-wide. My current and future work will investigate the hypothesis that these viral infections maybe in part responsible for symbiont loss.
Host-Symbiont Interactions
Insights into the establishment, maintenance, and alterations of microbial associations with metazoans can be gained from comparative and empirical metagenomics. My research has begun to evaluate changes in the metabolic potential of such communities, including insights into virulence and host evasion pathways of bacteria that are found in association with stressed corals. I will continue this work, focusing on both the microbial and host responses to these changes.
Bdellovibrios and their roles in regulating bacterial abundance on corals
A remarkable aspect of metagenomic pyrosequencing is the unprecedented amount of information that can be gained with no apriori knowledge of the system. An exciting observation gained from this experiment was an elevation in sequences related to Bdellovibrio phages and their host counterparts. Bdellovibrio sequences were found to increase in corals exposed to elevated carbon suggesting that introduction of a heterotrophic food source leads a concomitant increase in heterotrophic predators such as the Bdellovibrios. Little is currently known about the role that these bacterial predators play on coral reefs or in the coral holobiont. Future work using sequences identified in the metagenomes will be conducted to determine if the Bdellovibrios help regulate bacterial numbers on animal models and in tropical waters.
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