Fig. 8. Differential effect of flow on focal adhesion dynamics depends on focal adhesion orientation and not on their subcellular localization. PAECs expressing both CFP-vinculin and YFP-actin, were monitored, at two-minute intervals, before, and after application of flow (arrow, 20 dyn/cm²). (A) The last frame before application of flow is shown at the top left. To visualize flow-induced changes in focal adhesion structure, ratio images were generated for vinculin by dividing frame t+X by frame t (top right). For three vertical focal adhesion pairs (roman numbers) plus one perpendicular pair (P), a series of ratio images (2 minutes apart) is shown. Arrows and arrowheads indicate the upstream and downstream focal adhesions, respectively. (B) The change in area of each focal adhesion, as a function of time under flow (normalized to pre-flow values) is shown for the three pairs in A along with another nine pairs from other cells. The same color is used in both graphs to identify paired focal adhesions. Notice that the overall trend (marked by a black line) is growth of upstream focal adhesions and reduction is size of downstream focal adhesions. Bar, 5 µm.