Work under this ROW Research Planning Grant will be directed toward isolating a number of differentially expressed clones of a mutant gene that dramatically effects kidney function in mice. If the clones are new, they will be characterized by Northern hybridization and by sequencing. These clone libraries should provide an essential preliminary step to a better understanding of the molecular manifestations of this important mutant gene. Alternative methods of identifying this gene will be planned in order to enhance its eventual isolation. This mutant gene holds promise as an intriguing eukaryotic model system.