Fig. 4. An increase of Wg activity rescues the DNW phenotype. (A-D) Third instar ds^38k mutant wing discs. (A,B) Expression of UAS-wg (red) under the control of dpp-Gal4 driver rescues the DNW morphology to wild type. (B) The hinge territory is specified and the expression pattern of Hth (green) is restored. The hinge is enlarged in respect to wild type due to an increase in cell proliferation caused by ectopic Wg. (C,D) Ectopic expression of Dpp driven by omb-Gal4 increases the proliferation in the wing pouch but fails to rescue the notal duplication. (C) The size of wing pouch is increased. In some cases wing duplications can be recovered (wp and wp'); however, the double notal Wg (red) stripe indicates that the notum duplication is still retained. Dpp activity was monitored by Sal (green), a target gene of the Dpp pathway. (D) The symmetrical location of the AP border into the wing pouch territory is restored in ds^38k wing discs, as visualised by Ci (green) expression in A cells. Red channels (insets) show the notal Wg stripes.