Movie 2.

RGC growth cone expressing mNG-TOCA-1 (green) and GAP43-RFP (magenta), showing detail of filopodium formation, with two puncta of mNG-TOCA-1 moving laterally on the plasma membrane and coalescing before initiation. Image de-noised with nd-safir. Time relative to filopodium formation, scale bar 1 μm. 1 minute video acquired at 2 s per frame, replayed at 4 frames per second.