Mfn1 depletion and suppression of mitochondrial fusion and continuity in fibers from EtOH-fed rats. (A) Expression of mtDsRed and mtPA-GFP in FDB fibers harvested from EtOH-fed rats. Images show general structures of mitochondria (mtDsRed, pre-photoactivation) and organelle continuity and fusion events (mtPA-GFP, green boxes) in ethanolic- and pair-fed control fibers. White arrowheads, examples of mitochondrial continuity; orange arrowheads, fusion events. Plot on the right shows the frequency of fusion events (4 pairs of rats; ***, P < 0.001). (B) Mfn1, Mfn2, and Opa1 expression levels in control vs. EtOH SM mitochondria (representative of ≥9 experiments). (C) Mitochondrial continuity is attenuated by EtOH and restored by exogenous Mfn1 expression. The time course of the mtPA-GFP–positive mitochondrial area was quantified outside the region of photoactivation. Bar charts displaying mean positive area in μm2, 4 s after photoactivation. Data from three (control vs. EtOH) and four (EtOH vs. EtOH+Mfn1; *, P < 0.05) experiments.
