FIG. 2.

Abnormally elongated morphology of macrophages lacking both Abr and Bcr is phenocopied by activated Rac. PEMs of the indicated genotypes were plated on glass chamber slides and incubated for 24 h in the absence of CSF-1 (A), or BMMs of the wild type and double null mutants were cultured on glass chamber slides for 1.5 h (B, upper panel) or 24 h (B, bottom panels) in the presence of 120 ng/ml CSF-1. F-actin was stained with FITC-phalloidin (green), and nuclei were stained with DAPI (blue in panel A, red in panel B). Note that the double null BMMs already started showing the elongated morphology after 1.5 h in culture. Bars, 20 μm (A and C), 25 μm (B, top and bottom panels), or 50 μm (B, middle panel). (C) Wild-type BMMs were electroporated with the indicated constructs. Arrows point to cells expressing V12Cdc42. Cells were stained for nuclei (blue) and F-actin (red); EGFP-expressing cells appear green.