title: Saccharomyces cerevisiae petite mitochondrial DNA of suppressive and neutral haploids and of [rho-] diploids obtained from crossing [rho+] to a neutral petite.
abstract: An unusual property of GR25a [rho+] was the production of 20 to 30 percent [rho-] zygote colonies when crossed to a tester strain lacking mitochondrial DNA. Spontaneous [rho-] isolates of GR25a [rho+] were observed to be highly suppressive and to contain mitochondrial DNA of a parental buoyant density (1.685 g/cm3). Three ethidium bromide induced neutral petites of GR25 a [rho+] did not have detectable mitochondrial DNA and were neutral in crosses to [rho+] strains. Seven [rho-] zygote colony isolates obtained from crossing GR25a [rho+] to a neutral peptite were shown to contain abnormal mitochondrial DNA. Six zygote colony isolates had mitochondrial DNA of a buoyant density less than, or equal to, GR25a (1.682 - 1.685 g/cm3), whereas one isolate had a buoyant density greater than GR25a (1.688 g/cm3). It was suggested that abnormal mitochondrial DNA is generated during the mating reaction.
mesh_terms: D003433:Crosses, Genetic; D004272:DNA, Mitochondrial / Q000378:metabolism*; D004352:Drug Resistance, Microbial; D005111:Extrachromosomal Inheritance; D006238:Haploidy; D009154:Mutation; D010641:Phenotype; D012441:Saccharomyces cerevisiae / Q000502:physiology*; D013489:Suppression, Genetic
chemical_list: D004272:DNA, Mitochondrial