Fig. 8. E(spl)-mediated repression requires Gro. (A-A'') Wing pouch of omb-Gal4/hsFLP; UAS-sc UAS-E(spl)m7/EE4-lacZ; FRT82B gro^E48/FRT82B Myc. Homozygous clones for gro^E48 are marked by the absence of Myc (green) and ß-galactosidase is visualized in red. Intense EE4-lacZ expression is autonomously induced within gro mutant cells, indicating lack of repression. Arrows indicate wild-type cells that express low levels of EE4-lacZ. This low-level patchy expression in wild type is expected, as the overview of an omb-Gal4; UAS-sc UAS-E(spl)m7/EE4-lacZ (non-mosaic) disk stained by X-gal shows in B. It indicates that E(spl)m7-mediated repression is strong, yet not complete; compare with Fig. 2E-H. (C) hsFLP; FRT82B gro^E48/FRT82B Myc mosaic notum. Even though the clones are unmarked, we presume that they correspond to patches exhibiting bristle tufting. (D) hsFLP; ap-Gal4/UAS-E(spl)m7; FRT82B gro^E48/FRT82B Myc mosaic notum. Similar bristle tufts are observed, presumably corresponding to gro^E48 homozygous territories, within a bald background because of the overall expression of E(spl)m7, which suppresses bristles within the gro⁺ territories.