1. An attempt was made to superimpose a cytoplasmic mutation for respiratory deficiency ρ− over a nuclear mutation for oxidative phosphorylation deficiency by treatment of an oxidative phosphorylation-deficient yeast mutant op1 with acriflavine. Unlike wild-type yeast, cells of the mutant op1 grown in the presence of acriflavine did not form visible colonies after plating on solid medium with glucose as carbon source. 2. Growth of the op1 mutant in acriflavine-supplemented medium was limited. After about 10 generations the cells of the mutant ceased to multiply. They were then unable to respire, lacked cytochrome b and aa3 but seemed not to be dead since they fermented and assimilated glucose and did not stain with methylene blue. 3. In the culture of the op1 cells growing in the presence of acriflavine a considerable fraction of cytoplasmic respiration-deficient mutants was detected by crossing the cells with a neutral cytoplasmic mutant of opposite mating type. 4. Revertants from the op1 mutant which had grown in the presence of acriflavine gave rise to normal, viable respiration-deficient colonies after plating on solid medium. 5. It has been concluded that specific combination of the cytoplasmic ρ− and nuclear op1 mutations in a cell resulted in loss of multiplication ability. Implications of such a cumulative effect for the nature of op1 and ρ− mutations are discussed.

• PMID: 5682847
• DOI full text
• PubMed

Reference Type

Journal Article

Authors

Kovácová V, Irmlerová J, Kovác L

Primary Lit For

Additional Lit For

Review For