Figure 4. mma-1(RNAi)-induced mitochondrial hyperfusion is not dependent on ATFS-1 or HAF-1. (A) Strong depletion of MMA-1 protein (mma-1(RNAi)) leads to both mitochondrial hyperfusion and UPRmt response whereas mild depletion of MMA-1 protein (mma-1(RNAi) 1:5 dil.) only leads to UPRmt. Average relative ratios of MMA-1/Tubulin and Phsp-6GFP/Tubulin are indicated. Mitochondrial morphology in body wall muscles was assessed in L4 larvae of the F1 generation. Percentage of animals showing fragmented, tubular or hyperfused mitochondria are indicated (n >10 for each condition; average values are shown and error bars indicate s.d.). (B) Fluorescence microscopy analysis of wild-type Pmyo-3mitoGFP reporter strain (+/+) or Pmyo-3mitoGFP reporter strain carrying the haf-1(ok705) mutation or atfs-1(tm4525) mutation. (C-D) Quantification of the different mitochondrial morphologies observed (at least 15 animals were analyzed for each condition; two independent experiments were performed for panel C; three independent experiments were performed for panel D; average values are shown and error bars indicate s.d.).