Fig. 2. eya and dpp can bypass the requirement for hh to induce ectopic photoreceptor differentiation in the wing disc. (A-I) All panels show late third instar wing discs (anterior towards the left and dorsal upwards) with different combinations of UAS-transgenes driven by the 30A-GAL4 driver. (A,C,D,F) Misexpression of ey, dpp and eya (A,D), but not ey, hh, eya and so (C,F), in the wing disc induces Dac expression (A,C) and photoreceptor differentiation in the anterior and posterior compartments. (B,E) This effect is more penetrant when ey, dpp, eya and so are misexpressed. (G-I) Misexpression of ey, dpp, eya and so together in the wing disc in the presence of a lacZ enhancer trap in the hh locus (hh^P30). The same wing disc stained with anti-Dac (red, G), anti-ß-galactosidase (green, H) or a merge of the two channels (I) are shown. Dac expression is induced in a ring around the wing pouch (D) but hh expression (H) is restricted to the posterior compartment. (D-F) Photoreceptor differentiation is visualized by an antibody to the pan-neuronal protein Elav.