Fig. 3.

Nedd4 levels modify the α-synuclein-induced motor phenotype and dopaminergic cell number in Drosophila. (A) Accelerated loss of climbing ability was seen in transgenic flies expressing α-synuclein throughout the nervous system (elav-GAL4 driver). The climbing ability of doubly transgenic lines expressing Nedd4 and α-synuclein was significantly improved (shown by asterisks) when compared to α-synuclein expressing flies and was similar to the control genotype, elav-GAL4/+. (B) Unlike the result in the eye, reduction of endogenous Nedd4 specifically in the nervous system caused a worsening in the climbing scores, which were significantly different between doubly transgenic Nedd4 RNAi/α-synuclein compared to either α-synuclein or the control genotype, elav-GAL4/+ (error bars are hidden within the symbols). (C) No significant difference was detected when Nedd4 per se was overexpressed or knocked-down. *p < 0.05 using ANOVA with subsequent Tukey–Kramer test. Values represent mean ± SEM. (D) Kaplan–Meier survival curves were similar at different days after eclosion (DAE). (E) Dopaminergic neurons in the dorsomedial cluster were visualized with anti-TH antibodies and counted. (F) A significant loss of dopaminergic neurons was seen in Nedd4 RNAi/α-synuclein doubly transgenic flies when compared to α-synuclein or elav-GAL4/+ phenotypes. Co-expression of Nedd4 was protective against α-synuclein-induced cell loss (n = 10 brains/group). *p < 0.05 using ANOVA with subsequent Tukey–Kramer test. Values represent mean ± SEM.