Contamination and accumulation of xenobiotics (i. e., environmental toxins, chemical carcinogens, mutagens) in critical domestic and industrial water sources and natural reservoirs pose a significant health risk to humans and animals. While conventional methods to detect the presence of xenobiotics are available, they are not sensitive, they have to be complemented with other assays, and they are not designed to detect the pathobiological effects caused by exposure of organisms to sublethal levels of xenobiotics. Therefore, the development of a transgenic model for monitoring environmental xenobiotics is fundamental. Thus, the objective of Phase I is to construct a vector containing the luciferase reporter gene, fused to the regulatory elements (promoter) of the Pl-450 gene of rainbow trout, and introduce the vector into fish hepatoma cell lines. The activation of the Pl-450 regulatory elements by chemical carcinogens will be assessed by the enzymatic activity of luciferase and will be used as a molecular tool to evaluate sublethal levels of numerous polycyclic aromatic chemicals. These studies will constitute the basis to construct transgenic fish (Phase II) carrying the P450 promoter-luciferase fusion vector to assess toxins and polycyclic aromatic compounds capable of inducing toxicity and carcinogenesis. Thus, transgenic fish will serve as novel biological indicators of environmental xenobiotics.Awardee's statement of the potential commercial applications of the research: The project will provide an in vitro bioassay to evaluate dose-response of sublethal levels of xenobiotics and, subsequently, a sensitive transgenic model to monitor water quality. The bioassay can be used by environmental and regulatory agencies (e. g. EPA, DOA), by water resource managers and by water-related industries.National Institute of Environmental Health sciences (NIEHS)