FIG. 5.
Loss of D-Fos in proliferating cells causes apoptosis. (A) D-Fos expression was reduced in the posterior compartment of wing imaginal discs by enGal4 (enG4)-driven fosRNAi expression, and apoptotic cells were visualized by immunostaining with anti-activated caspase 3 antibody (shown in red). Many apoptotic cells were detected in the enGal4 domain (marked by EGFP expression [green]) but not in the anterior compartment, in which no fosRNAi was expressed. (B) In wild-type (WT) third-instar eye imaginal discs, apoptotic cells are scarce. (C and D) The expression of fosRNAi under the control of GMRGal4 (GMRG4) in the posterior eye imaginal disc, encompassing differentiating cells and the cells of the second mitotic wave (marked by anti-phospho histone 3 [PH3] staining [blue]), caused massive cell death in nonneuronal cells (Elav negative [Elav is in blue]). A distinct row of apoptotic cells emerges at a short distance behind the second mitotic wave.