Cell wall and DNA cosegregation in Bacillus subtilis studied by electron microscope autoradiography
Autor: | J M Schlaeppi, D Karamata, O Schaefer |
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Rok vydání: | 1985 |
Předmět: |
DNA
Bacterial Cosegregation Mutant Bacillus subtilis Biology Tritium Microbiology Acetylglucosamine law.invention Cell wall chemistry.chemical_compound Cell Wall law Microscopy Fragmentation (cell biology) Molecular Biology biology.organism_classification Microscopy Electron chemistry Biochemistry Biophysics Autoradiography Electron microscope DNA Thymidine Research Article |
Zdroj: | Journal of Bacteriology. 164:130-135 |
ISSN: | 1098-5530 0021-9193 |
DOI: | 10.1128/jb.164.1.130-135.1985 |
Popis: | Cells of a Bacillus subtilis mutant deficient in both major autolytic enzyme activities were continuously labeled in either cell wall or DNA or both cell wall and DNA. After appropriate periods of chase in minimal as well as in rich medium, thin sections of cells were autoradiographed and examined by electron microscopy. The resolution of the method was adequate to distinguish labeled DNA units from cell wall units. The latter, which could be easily identified, were shown to segregate symmetrically, suggesting a zonal mode of new wall insertion. DNA units could also be clearly recognized despite a limited fragmentation; they segregated asymmetrically with respect to the nearest septum. Analysis of cells simultaneously labeled in cell wall and DNA provided clear visual evidence of their regular but asymmetrical cosegregation, confirming a previous report obtained by light microscope autoradiography (J.-M. Schlaeppi and D. Karamata, J. Bacteriol. 152:1231-1240, 1982). In addition to labeled wall units, electron microscopy of thin sections of aligned cells has revealed fibrillar networks of wall material which are frequently associated with the cell surface. Most likely, these structures correspond to wall sloughed off by the turnover mechanism but not yet degraded to filterable or acid-soluble components. |
Databáze: | OpenAIRE |
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