FIG. 2.

Morphological characterization of the cdc42^D38E mutant. (A) Morphology of cdc42^D38E strain TRY38-2B at 30°C. Arrowheads indicate buds on multibudded cells. (B) Morphology and DNA contents of cdc42^D38E mutant strain TRY38-2B and wild-type C276-4A cells at 30°C shown by phase-contrast optics (top) and DAPI staining (bottom). Small arrowheads indicate buds on multibudded cells. Arrows indicate elongated-budded or multibudded cells containing single nuclei. Large arrowheads indicate multinucleate cells. Cells were grown in YEPD liquid medium to mid-log phase and sonicated briefly before observation. Bars, 10 μm. (C) Flow cytometric analysis of synchronized wild-type and cdc42^D38E mutant cell populations released at 23 or 30°C over 3 h. Arrows point to peaks representing cells with a DNA content of 1 or 2 N based on propidium iodide fluorescence. The broadness of the cdc42^D38E peaks at 30°C resulted from a population of multibudded cells with dimmer fluorescence than the standard fluorescence seen with cells with replicating DNA or 2-N DNA content.