Figure 4.

PFGE profiles of ρ⁺ mtDNA in MHR1 cells that overproduce Mhr1p. The MHR1 cells (W303a/pYES2) with only the vector pYES2, and the MHR1 cells (W303a/pYESMHR1) with the plasmid DNA bearing MHR1 inserted under the control of the GAL promoter (pYESMHR1) were cultured in galactose-containing medium (YPGal) at 30°C to mid-logarithmic phase (from 1 × 10⁵ to ∼5 × 10⁶ cells/ml). Then, the preparation of the total cellular DNA for PFGE and the PFGE were performed, as described in Ling and Shibata (2002). (A) The detection of signals from mtDNA, by using ³²P-labeled purified r⁺ mtDNA as a probe. (B) The detection of DNA under UV-light after ethidium bromide staining. λ ladder DNA (concatemers) and λ DNA digested with HindIII were used as size markers. Note that the relative intensities of the genomic size mtDNA (∼80 kbp) to the well-bound DNA were weaker in the Mhr1p-overproducing cells compared with the normal MHR1 cells.