Fig. 1. Distribution of Syph in Drosophila embryos and S2R+ cells. (A-D) Dorsal view of successively older wild-type stage 14 Drosophila embryos stained with an anti-Syph antibody. Boxed regions are shown at higher magnification in A'-D'. Syph is predominantly cytoplasmic at this stage. Note Syph accumulation in the leading edge (LE) cells (arrows in A',B') before the onset of dorsal closure (DC). This accumulation resolves to the dorsal-most edge of LE cells (arrows in C') and seam edge (arrowhead) during DC, and then subsides once closure is complete (arrow in D'). (E-G) S2R+ cells stained with an anti-Syph antibody (E,E'; green in G,G') and phalloidin to visualize actin (F,F'; red in G,G'). The boxed region in F is shown at higher magnification in E'-G'. Syph is found along filopodial extensions and at a subset of their tips (arrows in G'), but not all tips (arrowhead in E' and G'). Scale bars: 20 µm in A-D'; 2 µm in E-G'.