Fig. 5. Dpp signals through a D-h repression element and defines the domain of D-h expression. D-h-GFP (A) and HHRE-GFP expression (B) in wild-type leg imaginal discs. The insets in A, B and I show GFP expression in the basitarsal segment of a 4-hour prepupal leg. (C-E) Comparison of D-h-GFP expression (C) with dpp-lacZ expression (D). (E) Merge of images in C and D. (F,G) In legs with reduced dpp function (dppd6/dppd12), D-h-GFP expression (F) is significantly compromised, while HHRE-GFP expression appears normal (G). (H) GFP expression in a UAS-GFP/+; dpp-Gal4/+ leg imaginal disc. (I) In UAS-tkv^QD/+; dpp-Gal4/+ legs, Dpp signaling is elevated within dpp-expressing cells, resulting in partial ventral expansion and widening of the D-h-GFP stripe.