Fig. 4. Mutant rescue by targeted expression of eyg and ey. Expression pattern of E132-GAL4 (A) and ey-GAL4 (C) in late third instar eye-antennal disc were visualized by inducing UAS-lacZ expression and staining with X-gal (insets show expression in early third instar disc). (B) The eyg¹/eyg^M3-12 mutant phenotype (completely eyeless, see Fig. 2H) can be partially or completely rescued by targeted expression of eyg driven by E132-GAL4 and by ey-GAL4 (not shown). (D) The eyg^M3-12 mutant phenotype (headless, see Fig. 1D) can be rescued by ey>eyg with complete penetrance. (E) ey>ey can partially rescue the eyg¹/eyg^M3-12 mutant phenotype. (F) ey>eyg can partially rescue the ey²/ey^D eyeless phenotype.