Fig. 6. Enhanced potency of the QE response increases wing growth. (A-D) 5XQE>vg clones in wild-type Drosophila discs, black by the absence of CD2 (green, A,D), and by robust expression of 1XQE-lacZ (red, A,B) or Vg (C, blue). The clones are associated with expansion of the 1XQE-lacZ-expressing (wing) tissue, apparently at the expense of the rn-only domain, normally circumscribed by an inner and outer fold (dotted white and yellow lines, B-D, as indicated by the arrows). The disc in B is counterstained with Wg (blue) and uniform expression of Hsp70-GFP (green) to visualize the folds; the outer fold correlates with the inner ring of Wg expression. (D) Dll expression (summed staining for Dll and a Dll-lacZ transgene, blue) is not expanded within such 5XQE>vg clones. (E) Same as in D, except for the added presence of ubiquitous, ectopic Wg, driven under C765-Gal4/UAS control. Dll expression now extends into the expanded domain of wing tissue (marked by 5XQE-DsRed expression, red).