Figure 5.

SEM of RhoAV14-induced apical membrane structures and CDC42-induced filopodia. SEM was performed on serum-starved vector control (a), RhoAV14-transfected (b), and CDC42V12-transfected (c) NIH3T3 cells. Note the number and length of the apical membrane protrusions induced by the presence of activated RhoA. Three independent transfections were examined by SEM with more than 200 cells examined per transfection. The percentage of cells demonstrating the phenotype as shown for RhoAV14 or CDC42V12 was nearly identical to the percentage shown to be transfected by either GTPase when a parallel coverslip was analyzed by indirect immunofluorescence. Furthermore, <2% of vector-only transfectants had apical structures similar to those seen with RhoAV14, and they were highly reduced in number and size (ca. 20 per cell as opposed to 100–200). Bar, 10 μm.