title: The size of DNA molecules and chromatin organization in the macronucleus of the ciliate Didinium nasutum (Ciliophora).
abstract: Pulsed-field gel electrophoresis (PFGE) was applied to analyze the molecular karyotype of the ciliate Didinium nasutum. The data obtained indicate that D. nasutum belongs to the ciliate species with subchromosomal macronuclear genome organization. No short "gene-sized" DNA molecules were detected. Macronuclear DNAs formed a continuous spectrum from 50 kbp to approximately 1,000 kbp in size with a peak plateau between 250 and 400 kbp. The macronuclear DNA molecules were packed into chromatin bodies of 80-265 nm in size. Comparison of the PFGE and electron microscopic data shows that most if not all chromatin bodies contain more than one DNA molecule.
authors.affiliation: Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, 119991, Russia.
authors.forename: Vladimir I
authors.initials: VI
authors.lastname: Popenko
authors.forename: Alexey A
authors.initials: AA
authors.lastname: Potekhin
authors.forename: Bella P
authors.initials: BP
authors.lastname: Karajan
authors.forename: Sergei O
authors.initials: SO
authors.lastname: Skarlato
authors.forename: Olga G
authors.initials: OG
authors.lastname: Leonova
mesh_terms: D002843:Chromatin / Q000648:ultrastructure*; D016798:Ciliophora / Q000235:genetics*; D016054:DNA, Protozoan / Q000648:ultrastructure*; D016521:Electrophoresis, Gel, Pulsed-Field; D007621:Karyotyping; D048648:Macronucleus / Q000235:genetics*; D008854:Microscopy, Electron
chemical_list: D002843:Chromatin; D016054:DNA, Protozoan
keywords: chromatin bodies; electron microscopy; macronuclear DNA; pulsed-field gel electrophoresis