Fig. 5. Mitochondrial morphology in the temperature-sensitive tim23 mutant or in the [rho⁰] mutant. (A) Wild-type (YPH500/pAK2, panels a,b) and the temperature-sensitive tim23 mutant (SNY1010-3A/pAK2, panels c,d) cells were grown at 23°C in SCGal medium to express the pCOXIV-S65TGFP fusion protein. In panels b,d, cells were incubated at 37°C for 2 hours before fixation. Mitochondrial morphology was observed by GFP fluorescence. Bar, 2 µm. (B) Wild-type (SEY6210/pAK2, panel a) and its isogenic [rho⁰] mutant (SEY6210 rho⁰/pAK2, panel b) cells were grown at 23°C and fixed. Mitochondrial morphology was observed by GFP fluorescence. Bar, 2 µm.