Drosophila Clock Is Required in Brain Pacemaker Neurons to Prevent Premature Locomotor Aging Independently of Its Circadian Function
Fig 5
Specific loss of dopaminergic PPL1 neurons in Clk-deficient flies.
TH-IR cells were counted in confocal stacks of brains dissected from flies of the indicated ages and genotypes. In all panels, histograms display the mean ± SEM of TH-IR cell numbers in the PAL, PPL1, PPL2, PPM1/2 and PPM 3 clusters, from 2 independent experiments with 8–10 brains per genotype in each experiment. (A) At 10 days of age, the number of TH-IR neurons in the different dopaminergic neuronal clusters of Canton-S (ctrl), ClkAR and cyc0 flies was similar. (B) ClkAR mutants exhibited a selective loss of TH-IR cells in the PPL1 neuronal cluster at 31 days post-eclosion when compared to either controls or cyc0. (C) Loss of TH-IR cells in the PPL1 neuronal cluster was also observed at 31 days post-eclosion in ClkAR/+ heterozygote flies. (D) Reducing Clk levels in the PDF neurons specifically decreased the number of PPL1 TH-IR cells. PAL, protocerebral anterior lateral; PPM1-3, protocerebral posterior median 1–3; PPL1-2, protocerebral posterior lateral 1–2.