A) rbf mutant clones (A, white ommatidia) occupied slightly smaller areas in adult eyes as compared to the control wild-type clones (B, white ommatidia). (C and D) Mutation of w138 or hid in conjunction with rbf dramatically increased areas occupied by the mutant clones (C, rbf;w138, white ommatidia; D, rbf;hid, white ommatidia). (E and F) The morphology of w138, or hid single mutant clones was relatively normal with occasional extra number of interommatidial bristles. Mutant clones were generated using eyFLP/FRT method. Anterior of the eye is to the left and dorsal is up. (G-K) Mosaic clone analysis of activated Caspase 3 or pyknotic nuclei in third instar eye disc. Mutant clones were marked by absence of GFP shown in green. (G) rbf mutant clones spanning the MF displayed significantly elevated level of anti-activated Caspase 3 staining (Cas3 in magenta, white arrow). (H) rbf; w138 double mutant clones in the MF lack Cas3 staining. (I-K) High magnification images of DAPI staining to detect nuclear pyknosis in the MF region of the eye discs. (I) rbf mutant clones in the MF contained extensive pyknotic nuclei (bright magenta dots, white arrows). (J and K) Nuclear pyknosis was not observed in either rbf; w138 (J) or rbf; hid (K) double mutant clones. In all figures anterior of the eye disc is to the left and dorsal is up. Arrowhead points the MF groove.