The Role of Iron and Host-Derived Growth-Factors in Regulating Gene Expression in the Oyster Parasite Perkinsus marinus: Strategies for Inhibiting Proliferation
Two parasitic diseases of oysters, MSX and Dermo, have had a constant and unrelenting impact on adult oyster populations throughout the Bay. In the last six years, Chesapeake oyster populations have reached an all-time low, primarily due to Dermo disease. With a major breakthrough in the laboratory culture of the causative organism, researchers are now able to investigate the disease at the cellular level. Gerardo Vasta is focusing on the role of iron, critical to growth of both the parasite and its host. Because iron is generally much less available than other metabolic needs, competition for iron between oyster cells and parasites is intense.
Environmental factors in the Chesapeake may increase the availability of iron – for example, low oxygen conditions in the Chesapeake during summer months trigger chemical reactions in the sediments that release more soluble forms of iron into the water column. Increased iron in the waters may explain why Dermo is more prevalent during the summer in oysters located in poorly oxygenated regions. In this project, Vasta will detail the role of iron in regulating the proliferation of Dermo and will ascertain the importance of enzymes in the oyster's immune system to the growth and survival of the parasite. In the long run, this research should lead to genetically designed strategies for blocking infection and proliferation of the parasite. It could also provide a further rationale for nutrient reduction strategies adopted for the Bay and other estuaries.
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Gerardo R. Vasta and Adam G. Marsh
Center of Marine Biotechnology
University of Maryland Biotechnology Institute
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