Fig. 6. Mitochondrial tubular networks are maintained in ⁰ HeLa cells. (A) Total cell lysates from wild-type or ⁰ HeLa cells were analyzed by immunoblotting using antibodies targeting the indicated proteins. ⁰ HeLa cells completely lost the supercomplexes. (B) Mitochondrial fractions from wild-type or ⁰ HeLa cells were digitonin-solubilized, subjected to Blue-Native gel electrophoresis, and immunoblotted with antibodies against the indicated proteins. Arrowhead indicates the supercomplexes of complexes I, III and IV. (C) The ⁰ HeLa cells transfected with the plasmid carrying Su9-DsRed were analyzed by confocal microscopy. ⁰ HeLa cells maintain mitochondrial tubules, which are not expanded. Scale bar, 10 µm. (D) The ⁰ HeLa cells were fixed, and thin sections were visualized by electron microscopy. Arrowheads indicate mitochondria. Scale bar, 950 nm.