Fig. 8. Opa misexpression causes severe head malformations. (A) Wild-type head. (B,C) Adult heads from ey-Gal4>Opa. Eyes are absent. Arrowheads indicate antennal and aristal duplications and arrows indicate ectopic maxillary palps. (D) Adult head from ey-Gal4>Dpp. Eyes are present, but reduced. Arrowhead indicates misplaced antenna, arrows indicate maxillary palps. Note duplicated palpus on right. Asterisks represent outgrowths. (E) Wild-type and (F) ey-Gal4>Opa third instar imaginal discs stained with antibody to Dachshund. Note duplicated antennal ring, and lack of eye field staining in the ey-Gal4>Opa disc. (G) dpp^s-hc-lacZ expression in ey-Gal4>Opa discs. Note the small amount of the remaining eye disc (asterisk), and bifurcated dpp^s-hc-lacZ expression. (H) dpp^s-hc-lacZ expression in ey-Gal4>Dpp discs. Staining no longer extends into the eye disc, and extends further medially in the posterior antennal disc. Compare with Fig. 4A. (I) ey-Gal4>Dpp discs stained with antibody to Dachshund. Note partial duplication of antennal ring, and the expansion of the retinal field anteriorly throughout the entire eye disc.