Background
Coral reefs are among the most diverse ecosystems in the world and are home to a large variety of marine organisms. In addition to their ecological importance, coral reefs also have significant economic, aesthetic, and medicinal value, including the provision of compounds for biomedical research and therapies. At present, the health of coral reefs worldwide is threatened by a combination of natural and anthropogenic stresses. Global climate change is driving the increase in ocean temperatures, leading to coral bleaching and death. In an effort to save coral reefs, there is vast interest in understanding the dynamics of the coral holobiont—the animal and its associated microorganisms—and their capacity to acclimatize to climate change and survive. With drastic changes in temperature, climate change also impacts the coastline through sea-level rise and, consequently, the animals and humans living along the coast. Our research platform involves leveraging the knowledge of host-microbe interactions to assist marine invertebrates in combatting global climate change.
Cnidarian-Dinoflagellate Symbiosis
One of the crucial biological processes affected by stress is the interaction between the coral and its intracellular algae (dinoflagellates belonging to the family Symbiodiniaceae). Under normal environmental conditions, the algae exist in a mutually beneficial relationship with their hosts, providing the hosts with energy derived from their photosynthetic processes. However, stress can cause the breakdown of this symbiosis, and thus, “coral bleaching” (from the loss of algal pigments) and the death of the coral host. To better understand the physiological mechanisms that mediate both symbiosis establishment (i.e., initial infection) and breakdown, we use a laboratory model, the small sea anemone Aiptasia that is related to corals and hosts similar types of algae, but is easier to rear in the laboratory. We are interested in studying the molecular, cellular, and physiological processes that mediate symbiosis. Visit the Aiptasia Symbiosis Resource to learn more about how to use this model in your own lab or classroom!
Characterization of the Cnidarian Microbiome
While research within the last decade has focused on the cnidarian-dinoflagellate symbiosis, studies on cnidarian-bacterial and dinoflagellate-bacterial interactions still require greater attention. To better understand how cnidarians respond to environmental stress, intricate knowledge of the animal host and all its associated microbiota is necessary. This research aims to survey the entire bacterial community (microbiome) of Aiptasia under various environmental conditions. We are interested in (1) identifying important bacterial species that may be obligate symbionts of the host, (2) determining how these bacteria initially colonize host tissues, and (3) evaluating how different bacterial species impact host physiology and development. We use a combination of fluorescence microscopy, live-cell imaging, and microfluidics to accomplish these research goals.
Marine Invertebrate Larval Settlement
Settlement and metamorphosis of many marine invertebrate larvae depend on microbial biofilms. As sea levels and temperatures continue to rise due to global climate change, the composition and landscape of coastal biofilms will undoubtedly change and, in turn, affect the recruitment, settlement, and metamorphosis of different invertebrate larvae. We wish to determine bacterial-community composition of biofilms from impacted and non-impacted areas across different depths and temporal ranges and how this may affect larval settlement and the abundance of juveniles and adults of different invertebrates (e.g., sponges, bryozoans, annelids, mollusks, etc.). This is the newest area of research our lab is currently developing, given our recent relocation to San Diego. If you are interested in collaborating on this study, please contact us!