Fig. 3. Effects of irradiation and heat shock in wing disc development. (A-C) Untreated disc and adult wing of genotype hh-Gal4>UAS-p35 UAS-GFP. It shows normal wg expression (red) and a normal P compartment (green). The expression of wg is not affected by P35 and the differentiated wing in C is essentially normal, except a slight shortening of vein 5. (D-F) Disc and adult wing from larvae of the same genotype, but irradiated in the first larval period. Note the abnormal shape and bigger size of the P compartment (green) and the numerous foci of ectopic and elevated wg expression. wg expression in the A compartment remains normal. The antero-posterior demarcation line is highly irregular and there are indentations into the A compartment (arrow). The few flies that hatch after this early treatment differentiate wings with very abnormal and overgrown P compartments (F). (G-H) Disc of the same genotype dissected from a larva heat shocked at the first larval period. Note the appearance of numerous dots of ectopic wg expression in the P compartment and the protrusion into the A compartment (arrow). (I-J) Irradiated disc showing ectopic dpp expression in the P compartment. An arrow points to an indentation into the A compartment