Fig. 3. Wg signaling is required, but is not sufficient to activate vg-QE. (A-B) Wild-type wing disc showing the expression pattern of Vg (A) and dpp-GAL4 driver (B). (C,D) dpp-GAL4/UAS-N^intra-wing discs stained for Vg (C) and Wg (D). Activation of Vg by ectopic N^intra expression is non-cell autonomous whereas that of Wg is cell autonomous. (E) Dpp-GAL4/UAS-activated Arm showing cell-autonomous activation of Vg. (F1-4) Wing disc with arm^H8.6/arm^H8.6 mitotic clones. (F1) GFP marker (Ubi-GFP P[FRT]18A), (F2) vg-QE and (F3) DAPI staining. (F4) Merged image of F1-F3. Loss of GFP expression marks arm^H8.6/arm^H8.6 cells. vg-QE is not expressed in these clones.