Fig. 5. Reducing the dose of H and gro de-represses expression of the E(spl)m PNC reporter in SOPs. (A-H) Wing discs from late third-instar larvae carrying one copy of E(spl)m-GFP (green) in either a w¹¹¹⁸; A101/+ + (A,C-E) or w¹¹¹⁸; A101/H^E31 gro^E48 (B,F-H) background. (A,B,D,E,G,H) Antibody staining of ß-galactosidase expressed from the A101 enhancer trap insertion (magenta) marks SOPs. (C-E) Higher magnification of boxed region in A, showing exclusion of GFP signal from SOPs (arrows). ANWP, campaniform sensilla of the anterior notal wing process; APA, anterior postalar; PSA, osterior supraalar; PNP, posterior notopleural macrochaete. (F-H) Higher magnification of boxed region in B, showing ectopic GFP expression in SOPs (arrows). Reporter expression in non-SOPs is often reduced in this background. (I) Ectopic E(spl)m-GFP expression in SOPs is observed at much greater frequencies and intensities in w¹¹¹⁸; A101/H^E31 gro^E48 discs (dark green) than in w¹¹¹⁸; A101/+ + discs (light green). ANP, anterior notopleural; PDC, posterior dorsocentral; PSC, posterior scutellar. Only six discs (instead of 16) could be scored for GFP expression at the PSA position in the H^E31 gro^E48/+ + background, as the PSA SOP is often missing in this genotype (broken circle in F-H).