Fig. 4.

Light-specific Caspase-LOV–induced cell death in retinas of Drosophila. (A) Diagram of the mechanism of Caspase-LOV expression in specific tissues using the UAS-GAL4 system. Genomic enhancers are used to express GAL4 in specific tissues or subsets of cells. The GAL4 in these cells can then bind to the UAS, and the Caspase-LOV will be expressed. (B) Light-raised flies are grown in the light from the embryo stage, while dark-raised flies are grown in the dark from embryo. For other assays, flies were raised in the dark and then put in the light or kept in the dark upon eclosion. (C and D) Representative images of Drosophila eyes expressing N7/C-7 Caspase-LOV with GMR-GAL4 and raised in the light (C) and the dark (D). (E) Representative images of Drosophila eyes without Caspase-LOV expression raised in the light. (F–H) Cryosectioned whole heads of Drosophila stained with anti-chaoptin (green) for retinal marking, anti-dlg (red), and dapi (blue).