Figure 2.

Locating the suppressor(s) in revertants. (A) Growth of diploids that revertants (R1, R2, R3) or ρ⁰ of the revertants (R1ρ⁰, R2ρ⁰, R3ρ⁰) crossed to atp23 null mutant on YPD or YPEG medium. ρ⁰ colonies with complete deletion of mitochondrial DNA were obtained from revertants treated with ethidium bromide. (B) Growth of ρ^−sup colonies crossed to atp23 null mutant and mitochondrial DNA mutant testers on YPD and YPEG medium. ρ^−sup represents ρ⁻ colony with partial mitochondrial DNA fragment containing the suppressor. M28-82 and M7-40/A1 are atp6 and cob loss-of-function mutants, respectively (C) Diagram of localization of the suppressor(s) in mitochondrial DNA region of revertant R1. (D) Sequencing result of COX1 coding sequence within mitochondrial DNA fragment in ρ^−sup colony derived from revertant R1. (E) Sequencing results of COX1 coding sequence in mitochondrial genome of three revertants.