(A) Expression of Nord in the wing discs through the third instar larval and early pupal stage. Upper panel: the third instar wing discs from nord-GFP (Mi{PT-GFSTF.2}nordMI06414-GFSTF.2/+) larvae were collected at indicated time points after egg laying (AEL) and were immunostained for GFP (Nord, green) and the pro-domain of Dpp (red). Bottom panel: pupal wings from pupae carrying both nord-GFP were collected at indicated time points after pupation (AP) and were immunostained for GFP (Nord, green) and the pro-domain of Dpp (red). Scale bar, 100 μm. (B) Wing imaginal discs from third instar wild-type and nord mutant (nordMI06414) larvae were immunostained for pMad (green) and Ptc (red). Scale bar, 50 μm. (C) Plotted pixel intensity of pMad or Ptc as a function of A/P position. Each point shows the mean ± SD. n = 15. au, arbitrary units. (D) Anti-pMad staining in wild-type and nordMI06414 pupal wings at indicated hours AP. Scale bar, 100 μm. (E) Quantification of the width (yellow dashed line in panel D) of pMad signal at primordial posterior crossvein (PCV) at indicated time points. Each bar shows the mean ± SD from n > 10 pupal wings. The unpaired two-tailed t-test was used for statistical analysis. ****p<0.0001.