Abstract
Photosensitizers generating reactive oxygen species (ROS) upon light irradiation are commonly used in photodynamic therapy for tumor ablation. KillerRed, the first fully genetically encoded photosensitizer, gives red fluorescence and has a strong cell-killing effect upon irradiation with green light (Bulina et al., 2006). In this study, we generated the first transgenic fly carrying mitochondria localized KillerRed (2MLS-KillerRed). Using the UAS/GAL4 binary expression system, we show that specific Drosophila brain neurons expressing 2MLS-KillerRed can be effectively ablated with spatial and temporal precision. Expressing 2MLS-KillerRed in the entire mushroom bodies (MBs), we found that specific subsets of Kenyon cells composed of the MBs can be photoablated by irradiation at specific time window. We also used 2MLS-KillerRed to ablate Drosophila dorsal paired medial (DPM) neurons which innervate almost all MB lobes and take part in Drosophila olfactory learning and memory, and tried to explore a potential role of the DPM neurons in Drosophila sleep regulation. Finally, although photoablation appears to be more effective when multiple copies of 2MLS-KillerRed transgenes and a strong GAL4 driver are used, we notice that high doses of 2MLS-KillerRed will result in notable morphologic defects even without irradiation.