Fig. 4. Ectopic JAK/STAT signaling represses wg expression. (A,A') A third instar eye disc carrying hop flip-out clones and dpp-lacZ (Act>>hop/dpp-lacZ; UAS-GFP). hop flip-out clones (green) do not induce dpp-lacZ (anti-ß-Gal, red) expression. (A) Merge; (A') dpp-lacZ single channel. (B,B') A third instar eye disc carrying hop flip-out clones and wg-lacZ (Act>>hop/wg-lacZ; UAS-GFP). hop flip-out clones (green) repress wg-lacZ (anti-ß-Gal, red) expression in an autonomous manner. Repression is observed in the dorsal wg domain (outlined clones) and in the ventral domain (arrowheads). (B) Merge; (B') wg-lacZ single channel. (C) A third instar eye disc carrying ey>upd and wg-lacZ (ey>upd; wg-lacZ). Dlg (green), wg-lacZ (red), Elav (blue). Ectopic upd expression completely represses dorsal wg and strongly represses ventral wg (yellow arrow), allowing precocious photoreceptor differentiation from the lateral margin (arrowhead). (D-D') A third instar wing disc carrying hop flip-out clones and wg-lacZ (Act>>hop/wg-lacZ; UAS-GFP). hop flip-out clones (green) autonomously repress wg (red) in the notal region of the wing disc. (D) Merge; (D') magnified view of D; (D') wg-lacZ single channel in D'. (E,F) Dorsal views of adult heads carrying a stat92E^85C9 chromosome in a Minute background alone (E) or with the hypomorphic mutation wg^CX3/+; stat92E^85C9 M⁺ (F). Reducing the dose of wg slightly improves the stat92E^85C9 M⁺ adult phenotype. (G) Reducing the dose of wg, using the wg^CX3 allele, significantly increases the number of stat92E^85C9 M⁺ flies that eclose from the pupal case. Whereas only 9.7% of flies stat92E^85C9 M⁺ eclose (n=258), flies also carrying the wg^CX3 mutation hatch at a rate of 31.2% (n=266).