Figure 3.
Mitochondrial function in xenomitochondrial cybrids. (A) Oxygen consumption rates of six xenomitochondrial cybrids from each productive fusion and the human 143B and 143B/206 (ρ0) cell lines. Oxygen consumption values were measured with a Clark-type electrode on 2.5 × 106 cells in 3 ml of medium as described (14, 19). Each xenomitochondrial cybrid and human cell line was tested a minimum of six times. Error bars represent the standard deviation of the individual cell lines. Horizontal bars represent the average consumption rate of the combined “same species” xenomitochondrial cell. (B) Autoradiogram of a concave exponential gradient (15–20%) gel representing the resolution of the mitochondrially synthesized proteins. Cells were pulse-labeled with [35S]methionine/[35S]cysteine for 30 min in the presence of emetine, a cytoplasmic protein synthesis inhibitor. Cells were solubilized in SDS and subjected to PAGE as described (16). Individual mitochondrially synthesized polypeptides are identified on the left. Xenomitochondrial cybrids: HC, human/common chimpanzee; HP, human/pigmy chimpanzee; HG, human/gorilla.