EAPSI: Examining the Innate Immune Responses of the Pacific Coral Pocillopora Damicornis from Thermally Variable Reefs

Connelly Michael T, Miami FL

Investigators

Abstract

Coral reefs provide important benefits to coastal communities and are in worldwide decline due to rapid environmental change. Stony corals that build reefs are comprised of the cnidarian host, symbiotic algae and additional bacteria, fungi and viruses that are collectively termed the "coral holobiont". Disruptions that affect the healthy holobiont, such as high temperature stress due to climate change, are hypothesized to increase the incidence of coral bleaching and disease via immune suppression of the coral host. However, coral innate immunity research has been limited, and there is a poor understanding of in vivo host-microbe regulatory mechanisms. Nanwan Bay in southern Taiwan has unique oceanographic and bathymetric features that cause deepwater upwelling during spring tides, leading to temperature fluctuations as great as 10ºC over the course of a few hours. This highly variable temperature regime experienced by corals on reefs near upwelling regions in Nanwan Bay may contribute to increased resilience to thermal stress, although the physiological basis for enhanced tolerance is undetermined. During this EAPSI fellowship, recirculating aquarium experiments will use antibiotics, heat stress and immune stimulation to perturb the holobiont of the model coral species Pocillopora damicornis before gene expression, protein expression, and flow cytometry analyses are applied to assess the capacity for coral immune adaptation in variable temperature settings. The primary hypothesis is that temperature fluctuations caused by tidal upwelling in Nanwan Bay select for Pocillopora corals with a broader immune capacity to modulate microbial community shifts due to temperature variability. This research will be completed under the supervision of Dr. Pi-Jen Liu from National Dong-Hwa University in Kaohsiung, Taiwan, and will make use of the marine operations and aquarium facilities at the National Museum of Marine Biology and Aquarium in Kending. This award, under the East Asia and Pacific Summer Institutes program, supports summer research by a U.S. graduate student and is jointly funded by NSF and the Ministry of Science and Technology of Taiwan.