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Fig. 1. WIP overexpression increases PDGF-induced dorsal ruffle formation. (A)
Fluorescence micrographs of TRITC-phalloidin stained NIH 3T3 fibroblasts
transfected with control plasmid (3T3pcDNA) or with WIP coding sequence
(3T3pcDNA-WIP) before and after PDGF challenge. Cells were grown on glass
coverslips, serum starved for 4 days in the presence of 0.5% FBS, stimulated
or not with PDGF-bb (50 ng ml-1) for 8 minutes and then fixed and
labeled with TRITC-phalloidin to visualize actin filaments. Indicated cells
(Wort+PDGF) were pretreated with 12 nM wortmannin for 30 minutes at 37°C
and then stimulated with PDGF and stained as described. Magnification
400x. (B) Electron micrographs of cortical actin network of NIH
3T3pcDNA-WIP (left) and NIH 3T3pcDNA (right) fibroblasts stimulated as
described above. (C) Frames of phase-contrast microscopy capture of NIH
3T3pcDNA and NIH 3T3pcDNA-WIP fibroblasts grown on glass coverslips and
stimulated at 37°C with PDGF for the indicated times. Frames were
processed using Microsoft PowerPoint software. Arrows point to membrane
ruffles. Magnification 400x.