title: [Electron microscopy of mitochondrial DNA in Podospora anserina and the presence of a multimeric range of circular DNA molecules from senescent cultures].
abstract: Mitochondrial DNA from young cultures of race s of Podospora anserina was isolated. Its density in Cesium chloride density equilibrium gradients was 1.694 g/cc. Examination by the electron microscope revealed that ca 1% of this DNA consisted of circles, 31 micrometer in contour length; the remaining DNA was composed of linear molecules ranging in length from 2 to 33 micrometer. In DNA of similar density obtained from senescent cultures of the same race s, about 11% of the molecules consisted of a multimeric set of circles ranging in size from 0.9 to 15 micrometer, with most being in the 1.8 and 2.7 micrometer classes. The similarity of these DNA molecules with the mitochondrial DNA from rho(-) yeast mutants is discussed.
mesh_terms: D001203:Ascomycota / Q000235:genetics*; D046508:Culture Techniques; D004272:DNA, Mitochondrial; D008854:Microscopy, Electron; D008928:Mitochondria / Q000648:ultrastructure*; D009690:Nucleic Acid Conformation; D013098:Xylariales / Q000235:genetics* / Q000648:ultrastructure
chemical_list: D004272:DNA, Mitochondrial
vernacular_title: Etude au microscope électronique du DNA mitochondrial de Podospora anserina et présence d'une série multimérique de molécules circulaires de DNA dans des cultures sénescentes.