Dr. Kevin Swier
Department of Biological Sciences
Dictyostelium is the only model organism that allows classical genetic approaches to studying the fundamental cell biology of phagocytosis. We propose two novel fluorescent assays to screen Dictyostelium mutants for defects in signaling during phagocytosis. In the first screen, we will pulse Dictyostelium cells with fluorescent bacteria and sort for cells that cannot degrade the bacteria. For the second screen, we will construct a Dictyostelium cell line that fluoresces upon induction of the prestarvation response. We will then screen for Dictyostelium mutants that cannot inhibit this response in the presence of bacteria, their primary food source. These assays will identify novel genes involved in signaling during phagocytosis. Because phagocytosis in Dictyostelium is necessarily linked to decisions regarding cell growth and differentiation, we expect to establish Dictyostelium as a model system for investigating cellular mechanisms that integrate nutrient sensing, metabolic regulation and development.