Fig. 6. Notch regulates F-actin organization in the wing. (A-E') Third instar discs, stained for F-actin (green, shown from apical focal planes) and GFP (blue, marks Gal4-expressing cells), together with ap-lacZ (red, shown from basal focal planes) or Wg (red). (A) UAS-fng UAS-GFP ptc-Gal4. Normal Notch activation is observed at the DV boundary (arrowheads) and is disrupted near the AP boundary by ectopic Fng (asterisk), whereas ectopic Notch activation is induced along the AP boundary in ventral cells (arrow); corresponding changes occur in F-actin organization. In B-E arrowheads mark the normal DV F-actin line, arrows mark F-actin at clone edges. (B,C) A UAS-Dl UAS-GFP AyGal4 disc, with clones of cells expressing Delta. (D) A UAS-N-intra UAS-GFP AyGal4 disc, with clones of cells expressing N-intra. No autonomous influence on F-actin is observed, occasionally some upregulation is observed at clone edges, consistent with the ability of N-intra to induce Notch ligand expression. (E) Disc with a fat⁸ mutant clone, marked by the absence of GFP (blue). No influence on F-actin is observed.