Fig. 7. Effects of AML1-ETO and AML1-ETOZF expression on dpn. Discs were stained for Elav (red) and Dpn (green). The identity of the dpn-expressing photoreceptors is indicated to the right of the panels and an arrow indicates an individual R7 cell in each photograph. The asterisk next to B indicates cone cells differentiating as photoreceptors in lz^null eye discs. (A) dpn is normally expressed in differentiating R3, R4 and R7 photoreceptors (see also Fig. 1C). (B) In lz^null eye discs, dpn is expressed in the transformed cone cells (arrowhead). (C) In GMR-Gal4 UAS-AML1-ETO eye discs, dpn is repressed in R7 (although an occasional R7 cell weakly expresses dpn). No ectopic Dpn expression is observed. (D) dpn is not expressed in R7 in GMR-Gal4 UAS-lz-enR eye discs. (E) In GMR-Gal4 UAS-AML1-ETOZF eye discs there are more dpn-expressing R7 cells than in GMR-Gal4 UAS-AML1-ETO eye discs, suggesting that the zinc-finger domain is required for complete dpn repression in this assay.