Fig. 1.

Reduced Dpp production and transduction in the haltere. (A) Wild-type adult wing and haltere (arrow). (B) Third instar wing (W), haltere (H), and T3 leg (L) imaginal discs stained for Ubx (green) and a ubiquitous nuclear protein (blue). Ubx is present in all haltere disc cells but not in wing disc cells. (C) Removing Ubx activity (lack of GFP) from more than 50% of a haltere disc during larval development using the M⁺(Minute) technique (13) (SOM Text) increased its size [compare with discs in (B) and (F)]. (D)Isolated Ubx^- clones (black, -/-) were not larger than Ubx⁺ twin spots (bright white, +/+)ina Ubx heterozygous haltere (gray, -/+). (E) Ubx mutant:twin spot and neutral:twin spot clone size ratios. Error bars indicate SEM. (F to H) Wild-type wing and haltere discs stained for dpp-lacZ and P-Mad patterns. In the haltere, dpp-lacZ was reduced (arrowheads) and overlapped with a compacted P-Mad gradient (arrows).