Figure 4.

Suppressing dMfn in pink1 or parkin mutants attenuates eIF2α signalling and blocks neurodegeneration. (a and b) Decreased levels of phospho-eIF2α upon RNAi-mediated suppression of dMfn in pink1 (a) and parkin (b) mutant flies. Whole-fly lysates were analysed using the indicated antibodies. Ratios of signal intensity between phospho and total-eIF2α are shown at the top. (c and d) RNAi-mediated suppression of dMfn does not prevent the loss of Δψm in pink1 or parkin mutants. Representative confocal image of a whole mounted control brain showing neurons loaded with TMRM (c). Quantification of Δψm in the brains of the indicated genotypes (d) (mean±S.E.M.; asterisks, one-way ANOVA with Bonferroni's multiple comparison test). (e–g) The RNAi-mediated suppression of dMfn rescues the loss of dopaminergic neurons in the PPL1 cluster of pink1 and parkin mutant flies. Schematic diagram of a fly brain in sagittal orientation indicating the PPL1 cluster of dopaminergic neurons in red (e). Anti-TH staining showing cell bodies of PPL1 neurons in a representative control brain (f) and quantification of the PPL1 cluster neurons (g) (mean±S.E.M.; asterisks, one-way ANOVA with Bonferroni's multiple comparison test). (h and i) Suppression of the thoracic defects of pink1 and parkin mutants by RNAi-mediated suppression of dMfn. Representative images of normal and defective thorax in pink1 mutants, the arrow points to a thoracic defect (h). Quantification of the thoracic defects (i) in the indicated genotypes (asterisks, chi-square two-tailed, 95% confidence intervals). Genotypes for (a, b, i) Control: daGAL4; pink1^B9: pink1^B9,daGAL4; park²⁵: park²⁵/park²⁵,daGAL4. RNAi dMfn was driven by daGAL4. (c, d, f, g) Control: elavGAL4; pink1^B9: pink1^B9,elavGAL4; park²⁵: park²⁵/park²⁵,elavGAL4. RNAi dMfn was driven by elavGAL4. (h) Control: w¹¹¹⁸