Mfn accumulates in the absence of PINK1/Parkin. (A) S2R+ cells were treated with RNAi probe as indicated, harvested, and subjected to Western blot analysis by using antibodies against Drosophila Mfn. Antibodies against Complex Vα and actin are used as loading controls. (B) Wild-type and mutant animals were collected and subjected to Western blot analysis. Genotypes: w1118, wild type; Mfn RNAi, da-GAL4,UAS-Mfn-RNAi; park25, park25/park25; PINK1B9, PINK1B9/Y. Quantification of Mfn levels relative to the Complex Vα loading control in S2R+ cells (C) and wild-type and mutant animals (D). Charts represent mean and SEM for three independent experiments. Significance was determined by one-way ANOVA with Bonferroni correction (**P < 0.01, ***P < 0.001).