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Cytoplasmic inheritance of antimycin A resistance in Saccharomyces cerevisiae
Abstract:
Three antimycin resistant mutants of Saccharomyces cerevisiae are characterized genetically. The mutations have been shown to be cytoplasmically inherited by four criteria. The phenotype persists in diploids formed by a cross with a pO strain of yeast of the opposite mating type. Diploids heterozygous for the antimycin marker, however, show segregation of the resistance and sensitivity during mitosis. Tetrad analysis indicates a non-Mendelian segregation (4:0 and 0:4) of the mutations. The antimycin marker can be eliminated by ethidium bromide treatment under conditions that should have deleted all of the mitochondrial DNA.
Insights
Three Saccharomyces cerevisiae mutants resistant to antimycin were genetically characterized. These mutations exhibit cytoplasmic inheritance, showing non-Mendelian segregation and elimination with ethidium bromide, indicating mitochondrial DNA involvement.
Area of Science:
- * Molecular biology and genetics
- * Yeast genetics and mitochondrial inheritance
Background:
- * Antimycin is a potent inhibitor of mitochondrial electron transport.
- * Understanding drug resistance mechanisms in yeast is crucial for cellular biology research.
- * Cytoplasmic inheritance in Saccharomyces cerevisiae is primarily linked to mitochondrial DNA (mtDNA).
Purpose of the Study:
- * To genetically characterize three antimycin-resistant mutants of Saccharomyces cerevisiae.
- * To determine the mode of inheritance for antimycin resistance.
- * To investigate the role of mitochondrial DNA in conferring antimycin resistance.
Main Methods:
- * Genetic characterization of antimycin-resistant Saccharomyces cerevisiae mutants.
- * Analysis of inheritance patterns in diploid yeast strains and through tetrad analysis.
- * Treatment with ethidium bromide to assess the role of mitochondrial DNA.
Main Results:
- * Three antimycin-resistant mutants were identified in Saccharomyces cerevisiae.
- * Mutations demonstrated cytoplasmic inheritance, confirmed by four distinct criteria.
- * Segregation of resistance and sensitivity was observed during mitosis in heterozygous diploids.
- * Tetrad analysis revealed non-Mendelian segregation ratios (4:0 and 0:4).
- * Antimycin resistance marker was eliminated by ethidium bromide treatment, consistent with mtDNA deletion.
Conclusions:
- * The antimycin resistance in these Saccharomyces cerevisiae mutants is cytoplasmically inherited.
- * The observed inheritance patterns strongly suggest that the mutations are located within the mitochondrial genome.
- * Ethidium bromide's ability to eliminate the resistance marker further supports the involvement of mitochondrial DNA.