title: A limited loss of DNA compaction accompanying the release of cytoplasm from cells of Escherichia coli.
abstract: The DNA of bacteria is compacted into nucleoids. We have lysed cells of Escherichia coli under conditions in which the cell envelope is retained. The extent of DNA compaction was determined by light microscopy, comparing DAPI fluorescence and phase contrast images. The release of cytoplasm upon lysis allowed the nucleoidal DNA to expand to fill the residual cell boundaries, supporting the role of cytoplasmic crowding in nucleoid compaction. The addition of polylysine allowed lysis with retention of DNA compaction. Furthermore, chloramphenicol treatment of cells resulted in nucleoids which were more resistant to decompaction upon lysis.
authors.affiliation: Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD 20892-0560, USA.
authors.forename: L D
authors.initials: LD
authors.lastname: Murphy
authors.forename: S B
authors.initials: SB
authors.lastname: Zimmerman
mesh_terms: D016477:Artifacts; D002701:Chloramphenicol / Q000494:pharmacology; D003593:Cytoplasm / Q000378:metabolism*; D004269:DNA, Bacterial / Q000737:chemistry* / Q000378:metabolism*; D004278:DNA, Superhelical / Q000737:chemistry / Q000378:metabolism; D004926:Escherichia coli / Q000166:cytology* / Q000235:genetics; D004996:Ethidium / Q000378:metabolism; D005456:Fluorescent Dyes / Q000378:metabolism; D007211:Indoles / Q000378:metabolism; D007700:Kinetics; D008858:Microscopy, Phase-Contrast; D009113:Muramidase / Q000378:metabolism; D009690:Nucleic Acid Conformation / Q000187:drug effects
chemical_list: D004269:DNA, Bacterial; D004278:DNA, Superhelical; D005456:Fluorescent Dyes; D007211:Indoles; C007293:DAPI; D002701:Chloramphenicol; D009113:Muramidase; D004996:Ethidium