Small vesicle endocytic hot-spots triggered by lamellipodial contact. (A) Time-lapse confocal images of FM 5-95 internalization show an endocytic hot-spot where adjacent processes contact one another. The boxed area is magnified in the panels at the right and the time after the initial membrane labeling (mintes:seconds) is indicated in each frame. Lamellipodial contacts near the base of filopodia (red arrows) result in the formation of several small vesicles (yellow arrowheads) and subsequent membrane reshaping. For the corresponding time-lapse movie see Additional file 8. (B-C) Time-lapse DIC images show similar lamellipodial contacts and membrane remodeling as in (A). Note the contact between adjacent membrane processes (B, white arrows). The blue arrowheads indicate structures highly reminiscent of the reverse shadowcast vacuoles reported by Dailey and Bridgman . See Additional file 9 for the time-lapse movie corresponding to Figure 6B, C. Scale bars, 5 μm (left), 1 μm (right).