0504603 Vulpe This research will develop a DNA chip for the water flea, Daphnia magna, that can be used as a tool for water quality modeling. The hypothesis is that toxic pollutants will generate a characteristic gene expression profile in the Daphnia, which then can be measured using the DNA chip. The DNA chip would "calibrated" by control studies with specific priority pollutants, 44 are proposed for this initial exploratory research project. This project proposes an interesting integration of environmental toxicology and genomics to develop a new tool for water quality assessment.