Determining How Water Pollutants Affect Xenopus Frogs

This study examines how common pollutants present in water at doses below obvious toxic levels may affect the development of the frog immune system and lead to inefficient antiviral immune defenses during adulthood. The investigators will test three common water contaminants separately and in combination on the Xenopus laevis frog. This species has been chosen because of its extensively characterized immune system and available genomic resources. The investigators will expose Xenopus tadpoles to low doses of pollutants and evaluate the effectiveness of immune responses to a frog virus infection (the Ranavirus FV3) before and after metamorphosis. The finding that particular pollutants or combinations of pollutants at doses below detectable toxic effects can harm host immune defenses to Ranavirus pathogens may have a crucial effect on future decisions about the use of these different compounds and about their minimal acceptable doses. Additionally, given the high degree of genetic and functional similarities between Xenopus and mammalian immune systems, it is expected that outcomes from this study will apply to a wide variety of captive and wild aquatic vertebrates.