Fig. 6. Reduction of HOW levels elevates endogenous dpp mRNA. (A-C) In situ hybridization of wing imaginal discs with a dpp-specific probe carrying the sd-gal4 driver alone (A), or together with how-specific dsRNA (B) or with how(L)-specific dsRNA (C). Arrowheads indicate the sd-expression domain. Notice the specific elevation of dpp in the wing imaginal disc pouch in B and C. (D-I) Wing imaginal discs carrying the sd-gal driver and UAS-GFP together with how-specific dsRNA (D,E,F) or together with how(L)-specific dsRNA (G,H,I) stained for anti-HOW (D,G) and labeled with GFP (E,H). Their corresponding merged images are shown in F and I. Notice the specific reduction of HOW in the sd-gal4 expression domain in both D and G. (J-L) Adult wings of flies carrying the sd-gal4 driver alone (J), or in combination with how-specific dsRNA (K) or with how(L)-specific dsRNA (L). Arrows point to wing blisters. (M,N) Adult wings of flies carrying the ms1096-gal4 alone (M) or together with how(L)-specific dsRNA (N). Arrow points to extra veins.