Fig. 5. Effects of ubiquitous Hox activation on optix expression. (A) Wild-type, (B) 69B-Gal4>UAS-Ubx and (C) 69B-Gal4>UAS-tsh embryos: the gnathal patches of optix (arrowheads) are missing in the mutants but the head domains are largely as in wild type following late Hox induction. (D) nullo-Gal4>UAS-Ubx and (E) nullo-Gal4>UAS-AbdB. Early activation of Hox proteins eliminates both the head (asterisk) and gnathal expression domains of optix (compare with Fig. 2B,C). (F) 69-Gal4>UAS-Dfd. Late Dfd expression induces ectopic patches of optix in small lateral groups of cells in the thoracic segments (arrows) and enlarged gnathal patches (arrowheads, compare with Fig. 2B,C and 5A). (G) nullo-Gal4>UAS-lab. Early, but not late (not shown), induction of Lab results in lateral patches of optix in the thoracic segments (arrows) and enlarged optix patches in the maxillary and labial segments (arrowheads, compare with A). B,E-G are ventral views; A, C and D are lateral views.