Figure 8.

Arp2/3 complex removal alters focal adhesion patterns. (A) Representative images of fibroblasts (clone Arp3.19) with or without tamoxifen treatment and stained with anti-vinculin antibodies. A binarized threshold was applied to these stainings in order to facilitate automated analysis of adhesion numbers and sizes within distinct regions of interest (yellow outlines, defined manually). Note the exclusion of the cell center and perinuclear area due to the lack of staining resolution in these areas. (B) Calculation of adhesion number/cell, (C) adhesion number/cell area and (D) adhesion size were all based on data obtained from three independent experiments as described in (A). Box and whiskers plots were as described for Figure 4B. n = total number of cells analyzed. Statistics were performed utilizing the non-parametric Mann-Whitney rank sum test (***p < 0.001). Note that Arp3-deficient cells display more adhesions that are also bigger in size than Arp3-expressing controls. However, the adhesion number per cell area is reduced upon acute Arp2/3 complex removal as compared to control cells.