Fig. 8. Enhanced response to Dpp over-expression in coro mutants. (A,B) Low magnification images of dpp;GAL4/UAS-Dpp::GFP (A) and coro^ex11/coro^ex11; dpp;GAL4/UAS-Dpp::GFP (B) wing discs. Note differences in the size of the two discs. coro^ex11 and coro^ex6 heterozygous and coro^ex6/coro^ex6 and coro^ex6/coro^ex11 flies too showed enhanced growth response to Dpp-overexpression (data not shown). (C-E) Dpp::GFP-expressing wild-type (C), coro^ex11/coro^ex11 (D) and coro^ex6/coro^ex6 (E) wing discs stained for both GFP (green) and Arm (red). In the wild-type background, bright punctate spots of over-expressed Dpp::GFP are visible only in cells close to the AP boundary, the source of the morphogen. In coro mutant discs, bright spots of Dpp::GFP are visible in all cells of the disc, even in cells farthest from the AP boundary. (F,G) Dpp::GFP-expressing wild-type (F) and coro^ex11/coro^ex11 (G) wing discs shown at higher magnification. Note that in the coro^ex11 disc, bright spots of Dpp::GFP are larger, more numerous and mostly associated with the plasma membrane. (H,I) Intensity profile of wing discs shown in C and D, respectively. Posterior compartment cells immediately adjacent and parallel to the AP boundary were used for intensity profiling in both the discs. Note large number of Dpp::GFP peaks (green) outside Arm peaks (red) in wild-type background. However, nearly all DPP::GFP peaks coincide with Arm peaks in coro^ex11/coro^ex11 background suggesting that Dpp containing-vesicles are on the membrane. (J) coro^ex6/coro^ex6; dpp;GAL4/UAS-Dpp::GFP wing disc stained with FITC-conjugated actin-phalloidin. Note considerable rescue of actin cytoskeleton. Compare this disc with that of coro^ex6/coro^ex6 shown in Fig. 5C. (K) coro^ex6/coro^ex6; dpp;GAL4/UAS-Dpp::GFP wing disc stained with Arm (green) and FASIII (red). Note that the levels of both Arm and FASIII are now comparable to the wild-type (shown in Fig. 5D).