Fig. 7. Distribution of Arp2/3 in veils. (A) Growth cone immunostained against Arp3 subunit and phalloidin. Inset shows an enrichment of Arp3 (green) at the leading edge that co-localizes with phalloidin stained actin (red). (B) Low magnification growth cone (veil protrusion at 5.3 µm/minute) followed by time lapse and merges of boxed region. (C) Left. EM of region in lysed-live in B immunostained against Arp3 subunit. Right. Same EM overlaid with a 0.5 µm grid colored to reflect the number of gold particles in each box; heat map indicates number of gold particles per 0.25 µm2 box. Similar to A, Arp3 staining co-localizes with actin and is highest at the leading edge of protruding veils. (D) High magnification of the boxed region from C. Gold particles have been pseudo-colored yellow.