Increase of DPH fluorescence polarization during development of Dictyostelium discoideum cells

AbstractWhole cells of the eukaryotic microorganism Dictyostelium discoideum have been assayed with membrane fluorescence polarization probes. With diphenylhexatriene (DPH) the steady-state fluorescence polarization remained stable during growth, but significant rise was found as a function of time of development. This variation, discussed as being specific to the plasma membrane, is the first report of a biophysical change occurring at this level during cellular aggregation of D. discoideum. In contrast, with trimethylammonium (TMA)-DPH no change was observed during development. The differences obtained with the two probes are discussed in the light of complementary fluorescence anisotropy decay measurements