Figure 4

Mitochondrial content, morphology and respiration in bcl2l13 KO muscle

(A) Representative immunohistochemistry of transverse muscle sections of WT and KO fish stained with phalloidin (red). Mitochondria are marked with an antibody against MCTO1 (green, merge is yellow).

(B) Mitochondrial area in fast muscle fibers.

(C) Representative micrographs with ROI and mitochondria circling (yellow overlays) and zoomed section (black squares).

(D–F) Analyses of IMF mitochondrial parameters.

(G–K) Oxygen consumption rates normalized to mitochondrial content with Mitotracker Deep Red (OCR/MTDR). Black vertical lines indicate addition of substrates and electron transport chain (ETC) complexes inhibitors. (H–J) Mean ETC complex I activity (CI), complex II activity (CII), and complex IV (CIV) activity. For (D–F), n = 5 WT and 6 bcl2l13 KO zebrafish. For (G–K), n = 8 biological replicates per group. For all panels, error bars are mean ± SEM. ^∗p < 0.05, ^∗∗∗∗p < 0.0001 (unpaired t test). WT: Wild type and KO: Mutant bcl2l13. IMF is intermyofibrillar, SS is subsarcolemmal, CI–CIV are ETC complexes I to IV, NADH is beta-nicotinamide adenine dinucleotide, Succ is succinate, ROT is rotenone, AA is antimycin A, TMPD is N,N,N′,N′-tetramethyl-1,4-phenylendiamin, Asc is ascorbic acid.

See also Figure S3.