D In the wing imaginal disc, dL(3) mbt overexpression in the dorso-ventral (D-V) boundary results in the downregulation of the Notch target gene cut. Wing discs expressing UAS-GFP (top panels) or UAS-HA-dL(3) mbt;UAS-GFP (bottom panels) under the vg-Gal4 driver at 25°C were stained for cut and HA. GFP marks the vg-Gal4 expression domain. Insets below each panel show a closer view of the D-V boundary with yellow arrows marking the regions where HA-dL(3) mbt is expressed and cut is downregulated. At least 20 discs for each genotype were analyzed. Representative images are shown. Scale bars: 100μm. 