Fig. 5. Hh spreading is not impeded in ptc¹⁴ mutant clones but signaling is normal. (A,C,E) Wild-type expression of the Hh targets En (red) and Ci (green) (A), Col (red) (C) and Dpp (red) (E) in the third instar wing imaginal disc. (B,D,F) Activation of En, Col and Dpp (red) in ptc¹⁴ mutant clones abutting the AP compartment border (labeled by the lack of green GFP staining) (clones 2, 4 and 6) but not in clones outside the AP border (clones 1, 3 and 5). Note that Hh target gene activation occurs not only inside the clone touching the AP compartment border but also in cells located more anterior to the clone (arrowheads). The plots (right) show the fluorescence intensity for each target gene with respect to the distance of the cells to the AP border. The activation of the target genes occurs inside and anterior to the clone (arrowheads). Of 62 clones in the A compartment with A sister clones, 39 were located outside of the AP compartment border and did not show ectopic expression of En, Col and Dpp, and 23 were touching the compartment border showing activation of the targets inside and also in cells located anterior to the clone. (b) GFP signal and Ci staining of the disc in B. The clone touching the AP border has its twin in the A compartment (red arrow). The presence of the Ci staining sets the position of the AP border (red arrowhead). Scale bar: 50 µm.