Figure 1. PR36 causes selective neuronal death in motor neurons but not in dopaminergic neurons. A, B, The effects of motor neuron-expressed PA36 or PR36 on climbing and life span. Male, control (CTRL) genotype: D42-Gal4/+. Mean ± SEM, n = 3 tubes, one-way ANOVA. C, Representative images showing the loss of motor neurons expressing PR36 at indicated ages. As reliable antibodies for DPRs or for Drosophila motor neurons were not available, D42>mCD8::GFP was used to label the motor neuron population. Note that PR36 caused motor neuron loss when compared with the control PA36, and the neuronal loss progressed with aging. Decreased fluorescent intensity at antennal lobe (indicated by the dashed lines), a neuropil of motor neurons, was observed in PR36-expressing flies. The images were taken under identical parameters including the equivalent value of laser intensity, gain, offset, and pinhole and were shown as Z-stack projection. D, The quantification of the fluorescence in antennal lobe. Mean ± SEM, n = 4 male flies, two-way ANOVA. E, F, PR36 failed to cause neuronal loss in dopaminergic neurons in 30-d-old flies. Dopaminergic neurons in posterior brain were labeled with an anti-tyrosine hydroxylase (TH) antibody. Circles indicate protocerebral posterior lateral 1 (PPL1) clusters of TH-positive neurons. The quantification of the PPL1 TH-positive neurons is shown in F. Mean ± SEM, n ≥ 9 male flies for each genotype, unpaired t test.