Overexpression of MFN1 and MFN2, but not OPA1, restores mitochondrial network in C2C12-A1 cells. (A–D) Confocal image analysis of mitochondrial network in C2C12 cells stably expressing vector control (A and B) or ALCAT1 (C and D). The stable C2C12 cell lines were transiently transfected with mitochondrial-targeted EGFP expression vector (A and C) and stained with MitoTracker Red (B and D) before imaging. (E–J) Confocal image analysis of mitochondrial network in C2C12 cells stably expressing ALCAT1 and transiently transfected with expression vectors for Myc-tagged MFN1 (E and F), MFN2-YFP (yellow fluorescence protein) (G and H), or Myc-tagged OPA1 (I and J), respectively. For the Myc-tagged proteins, cells were first stained with MitoTracker Red and then fixed, followed sequentially by immunostaining with mouse anti-Myc antibodies and goat anti-mouse FITC-conjugated secondary antibodies (green). (Scale bar: 5 μm.)