Assistant Professor of Biology and Marine Sciences
Ph.D. Marine Biology, University of California San Diego, Scripps Institution of Oceanography, 2006.
B.S. Biology, Mount Holyoke College, 1998.
Biological Oceanography (MS102N), Comparative Physiology (BI314)
My interests are centered on the microbial ecology of a wide range of marine invertebrates, including corals, sponges, tunicates, bryozoans, and bivalves. My research includes the use of molecular tools, field work, and advanced microscopy. My current research efforts are focused on 1) prokaryotic (bacterial and archaeal) communities within gametes, larvae, and early life stages of tropical corals, 2) interactions between prokaryotic communities and symbiotic dinoflagellates (Symbiodinium) in corals, and 3) research of bioactive metabolite symbiosis in marine invertebrates.
- The coral Porites astreoides, a scleractinian (hard) coral that can be found in the Caribbean and the Florida Keys, releases fully competent larvae into seawater. These larvae possess Symbiodinium sp., photosynthetic symbionts. Our recent fieldwork in the Florida Keys and in Belize, has shown that upon release, P. astreoides larvae also harbor a bacterial assemblage, similar in composition to what is seen in some adult corals, and this bacterial assemblage is rather consistent across a large spatiotemporal scale in the Caribbean and the Florida Keys. Bacteria are transmitted from parent to offspring in the larval ectoderm, and during the swimming larval (planula) stage and post-settlement stages, bacteria colonize the surface of the juveniles. Our latest data from this project suggest that some bacteria in the seawater influence larval settlement success. This research is ongoing in my laboratory and has been funded by the “Protect Our Reefs” license plate grant from Mote Marine Laboratory.
- Using the facultatively symbiotic coral Astrangia poculata as our study organism, my collaborators and I have worked to characterize the diversity and dynamics of bacterial communities associated with asymbiotic and symbiotic individuals of A. poculata from New England habitats. Using microscopy and DNA pyrosequencing technologies, we are determining whether the presence of symbiotic zooxanthellae Symbiodinium sp. influences the makeup of bacterial communities in and on the coral host. Astrangia poculata, which occurs frequently in the wild without Symbiodinium, offers us the unique ability to test the influence of Symbiodinium on many aspects of coral biology, including the bacterial community dynamics. This work has been based primarily on New England corals, but we hope to expand this work to A. poculata populations on the Florida coasts and the southeast coast of the United States.
- Sessile marine invertebrates are a rich source of diverse bioactive compounds that have potential use in the biotechnology, biomedicine, and pharmaceutical arenas. I am particularly interested in the biosynthesis of bioactive compounds by microorganisms, including bacterial symbionts in marine invertebrates. In previous work, I have localized the bacterial biosynthesis of bryostatins in the cosmopolitan, temperate bryozoan Bugula neritina, and I use microscopy and DNA-based techniques to describe the transmission of specific bacteria that may be producing bioactive metabolites in invertebrates such as sponges, bryozoans, and tunicates (sea squirts).
Dimond, JD, Kerwin, A, Rotjan, RD, Sharp, KH, Stewart, F, and DJ Thornhill. A simple temperature-based model predicts the upper latitudinal limit of the temperate coral Astrangia poculata. Coral Reefs (in press).
Sharp, KH, & Ritchie, KB. 2012. Coral-associated bacterial communities in the face of global climate change. Biological Bulletin 223(1): 66-77.
Sharp, KH, Distel, D, & Paul, VJ. 2011. Diversity and dynamics of bacterial communities in early life stages of the Caribbean coral Porites astreoides. Journal of the International Society for Microbial Ecology 6: 790-801.
Paul, VJ, Ritson-Williams, R, and KH Sharp. 2011. Marine Chemical Ecology in Benthic Environments. Natural Products Reports 28(2): 345-387.
Sharp, KH, Ritchie, KB, Schupp, P, Ritson-Williams, R, and VJ Paul. 2010. Bacterial acquisition in juveniles of several broadcast spawning coral species. PLoSOne 5(5): e10898.
Trindade-Silva AE, Lim-Fong GE, Sharp KH, Haygood MG. 2010. Bryostatins: biological context and biotechnological prospects. Current Opinion in Biotechnology 21(6).
Sharp, KH, Arthur, KE, Gu, L, Ross, C, Harrison, G, Gunasekera, SP, Meickle, T, Matthew, S, Luesch, H, Thacker, RW, Sherman, DH, and VJ Paul. 2009. Phylogenetic and chemical diversity of three chemotypes of bloom-forming Lyngbya species (Cyanobacteria: Oscillatoriales) from reefs of southeastern Florida. Applied and Environmental Microbiology 75(9): 2879-88.
Paul, VJ, Arthur, K, Ritson-Williams, R, Ross, C, and KH Sharp. 2007. Chemical Defenses: from compounds to communities. Biological Bulletin 213: 226–251.
Sharp, KH, Davidson, SK, and MG Haygood. 2007. Localization of “Candidatus Endobugula sertula” and the bryostatins throughout the life cycle of the host bryozoan Bugula neritina. Journal of the International Society for Microbial Ecology 1: 693-702.
Sharp, KH, Eam, B, Faulkner, DJ, and MG Haygood. 2007. Vertical transmission of diverse microbes in the tropical sponge Corticium sp. Applied and Environmental Microbiology 73(2): 622–629. ** This article highlighted in Editor’s Choice, Science (2007) 314:1842.
Hildebrand, M, Waggoner, LE, Lim, GE, Sharp, KH, Ridley, CP, and MG Haygood. 2004. Approaches to identify, clone and express symbiont bioactive metabolite genes. Natural Products Reports 21(1): 122-142.
Trapido-Rosenthal, HG, Sharp, KH, Galloway, TS, and CE Morrall. 2001. Nitric oxide and cnidarian-dinoflagellate symbioses: pieces of a puzzle. American Zoologist 41(2): 247-257.