Fig 3. Toy/Tsh are required for growth of the entire eye-antennal eye disc during early larval instars.
(A-M) tub-GAL80ts; DE>toy RNAi + tsh RNAi. (A,D,G,J) Dorsal view of adult heads. (B,E,H,K) Side view of adult heads. (C,F,I,L) Light microscope images of eye-antennal discs from third instar larvae. Anterior is to the right. Eye-antennal discs were stained with an antibody that recognizes the pan-neuronal marker ELAV. The green arrow marks the presence of partially formed eye disc and the red arrows mark the greatly reduced eye-antennal discs. (M) Time-course for the restoration of Toy/Tsh to the eye-antennal disc. Embryos/larvae were first kept at the non-permissive temperature of GAL80 (30°C) for the times listed on the X-axis before being shifted to the permissive temperature (18°C). Animals were either dissected as late third instar larvae or allowed to reach the pharate adult stage. The graph shows the percentage of animals that were scored (Y-axis) during each experiment. Depending upon the temporal window at which Toy/Tsh are restored to the eye antennal discs, it is possible to either fully (A-C,M) or partially (D-I) rescue defects to the eye, antenna, and head epidermis. However, it becomes exceedingly difficult to restore the eye-antennal disc after the first larval instar. (N ≥ 100 in each experiment) (Scale bars, 100 μm).