Wing imaginal discs were labeled for Cut as Notch activity marker in red. Clones over-expressing D-cblL (A,A′), D-cblS (B,B′) and EGFRDN (C,C′) were obtained by crossing the corresponding UAS lines to hs-Flp; tub<GFP<Gal4 flies, and are negatively marked by the absence of GFP. The top panels of each experiment are the combined GFP and Cut channels, the (′) panels are the Cut labelings only. Expression of D-cblS reduced expression of Cut (B,B′, arrow). Induction of D-cblL (A,A′) and EGFRDN (C,C′) did not affect Cut expression. White lines mark the clone boundaries.
Expression of D-CblS (E,E′) specifically along the AP boundary of wing discs by dpp-Gal4, positively marked by GFP, strongly suppresses Cut expression (arrow in E′). Expression of D-cblL (D,D′) and EGFRDN (F,F′) have no effect in this assay. The UAS-D-cblL (line A18) and UAS-D-cblS (line A1) transgenes were used.