Fig. 6. Regulation of IroRE²-lacZ by Pnr. (A-B') pnr^VX6 mutant cells (absence of green) show ectopic expression of IroRE²-lacZ (red) when located in the medial notum (arrows in A,A') but abolish expression in the wg notal domain (shown in blue, arrows in B,B'). In this region, expression of pnr (visualized in pnrGal4/UAS-GFP larvae) overlaps with that of IroRE²-lacZ (not shown). (C,C') Overexpression of UAS-pnr (green), activates IroRE²-lacZ at the hinge and alula domains (arrowhead) and alter the disc epithelium of the prospective lateral notum forming a fold around some clones (arrows). lacZ ectopic activation was stronger at the hinge, alula and pleura than at the wing pouch, consistent with a weak activation of ush by overexpressed pnr at this domain (A.L. and S.C., unpublished).