Fig. 1. MTOC polarization over the time course of wound closure using NIH 3T3 fibroblasts. (A) Co-labeling of wounded NIH 3T3 monolayers for tubulin and pericentrin. NIH 3T3 fibroblasts were fixed and stained for MTOC concomitantly with the anti-tubulin antibody (top panels) and with the anti-pericentrin antibody (bottom panels), 3 hours post wounding. Enlarged pictures of positively scored MTOC polarization are shown on the left panels and correspond to a region from the middle panel as indicated. Using white dotted lines, we indicate the 120° sector facing the wound. (B) The percentage of wound-edge cells with a MTOC orientated towards the wound was determined at 3, 5 and 7 hours post wounding. (C) Quantification data. The first number corresponds to the number of MTOC observed; the second, in parentheses, is the number of separate experiments. Bar, 40 µm.