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Updated: Aug 19, 2026
A Deep-sequencing-assisted, Spontaneous Suppressor Screen in the Fission Yeast Schizosaccharomyces pombe
Published on: March 7, 2019
Segregational respiratory-deficient mutants of a "petite negative" yeast Schizosaccharomyces pombe 972h-
Abstract:
No viable respiratory-deficient mutants of Schizosaccharomyces pombe 972h(-) could be obtained by acriflavine and ethidium bromide treatments. These mutagens induce 15 to 70% of microcolonies which, after a growth-lag of a few days, further develop into normal, respiratory-competent colonies. These results suggest that unstable petites were induced. Segregational respiratory-deficient mutants resistant to cobalt sulfate inhibition were isolated. Some of these strains are deficient in cytochrome a + a(3) and respire at low rates. The morphology of their mitochondrial membranes is modified: either the cristae are absent or they show aberrant concentric or tubular structures. Segregational mutants resistant to the respiratory inhibitors, 2,4-dinitrophenol or decamethylene diguanidine, were obtained. Neither mitochondrial structure nor function seems to be modified in these mutants. A segregational mutant resistant to benzimidazole inhibition does not grow on glycerol, although neither growth on glucose nor respiration appear to be affected.
Insights
Researchers explored respiratory-deficient mutants in yeast. Acriflavine and ethidium bromide induced unstable petites, while segregational mutants showed altered mitochondrial structures and inhibited respiration.
Area of Science:
- Molecular and Cellular Biology
- Yeast Genetics
- Mitochondrial Research
Background:
- Investigating respiratory-deficient mutants in the fission yeast Schizosaccharomyces pombe is crucial for understanding mitochondrial function.
- Previous studies utilized chemical mutagens to induce mutations affecting cellular respiration.
Purpose of the Study:
- To characterize respiratory-deficient mutants of Schizosaccharomyces pombe induced by acriflavine and ethidium bromide.
- To isolate and analyze segregational respiratory-deficient mutants with resistance to specific inhibitors.
Main Methods:
- Treatment of Schizosaccharomyces pombe with acriflavine and ethidium bromide to induce mutations.
- Isolation of respiratory-deficient mutants resistant to cobalt sulfate, 2,4-dinitrophenol, decamethylene diguanidine, and benzimidazole.
- Analysis of mitochondrial morphology and respiratory function in isolated mutant strains.
Main Results:
- Acriflavine and ethidium bromide treatments did not yield viable respiratory-deficient mutants but induced unstable petites.
- Segregational mutants resistant to cobalt sulfate exhibited deficiencies in cytochrome a + a(3), reduced respiration, and altered mitochondrial membrane structures.
- Mutants resistant to other inhibitors showed no significant changes in mitochondrial structure or function, except for a benzimidazole-resistant mutant unable to grow on glycerol.
Conclusions:
- The chemical mutagens acriflavine and ethidium bromide primarily induce unstable petite mutations in Schizosaccharomyces pombe.
- Segregational respiratory deficiency in yeast can lead to distinct alterations in mitochondrial morphology and respiratory chain components.
- Specific inhibitor resistance in yeast mutants can reveal complex interactions between mitochondrial function, respiration, and metabolic pathways.
