title: Extrachromosomal inheritance in Schizosaccharomyces pombe. VII. Studies by zygote clone analysis on transmission, segregation, recombination, and uniparental inheritance of mitochondrial markers conferring resistance to antimycin, chloramphenicol, and erythromycin.
abstract: Crosses involving mitochondrial markers conferring resistance to antimycin (anar, AR), chloramphenicol (capr, CR), and erythromycin (eryr, ER) in cis- and trans-configuration were studied by zygote clone analysis. Mutant anar-8, from which all other drug--resistant isolates were derived, exhibits a highly biased transmission (6.8% anar) in an analysis of 100 individual zygote clones. Important results of zygote clone analyses were:--Zygote clones may contain one, two, three, or four mitochondrial genotypes.--The proportion of the two parental and the two recombinant genotypes in individual zygote clones can vary almost over the entire range of percentages.--Proportions of the two corresponding recombinant types in individual clones are usually unequal.--Transmission rates of markers are higher in trans- than in cis-crosses, indicating additivity of bias by two mutated alleles in coupling.--Transmission rates are different for the three markers both in cis- and trans-crosses, being lowest for CR and highest for ER.--Up to more than 80% uniform clones, expressing only one genotype, can be produced in cis- and trans-crosses. In cis-crosses always the double-sensitive parental type becomes uniform, in trans-crosses this may be the case for parental and/or recombinant genotypes. A tentative map is presented using data from cis- and trans-crosses, including a correction by omission of uniform clones. Phenomena of transmission, segregation, and formation of uniform clones are discussed with special regard to the difference brought about by fission versus budding. A comparison with relevant data from Saccharomyces cerevisiae and other organisms is presented.
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D000968:Antimycin A / Q000494:pharmacology; D001203:Ascomycota / Q000235:genetics*; D002701:Chloramphenicol / Q000494:pharmacology; D003433:Crosses, Genetic; D004272:DNA, Mitochondrial; D004352:Drug Resistance, Microbial; D004917:Erythromycin / Q000494:pharmacology; D005796:Genes; D005838:Genotype; D011995:Recombination, Genetic; D012568:Schizosaccharomyces / Q000187:drug effects / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D004272:DNA, Mitochondrial; D004917:Erythromycin; D000968:Antimycin A; D002701:Chloramphenicol