Electron Microscopic Observations on Bacterial Nuclei

Bradfield, J. R. G.

doi:10.1038/173184a0

Cited by 44 publications

(9 citation statements)

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“…39). These areas correspond to those of similar structure described in sections of cells of other bacterial species (1,2,4,10). In R. rubrum the strands contained in these chromatin areas constitute the most delicate and variable structures of the cell, with respect to processing the cells for sectioning.…”

Section: Discussionsupporting

confidence: 81%

The Structure of Rhodospirillum rubrum

Hickman

Frenkel

1959

The Journal of Cell Biology

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Cells from serial cultures of R. rubrum, grown anaerobically in the light, were harvested at intervals from ~/~ to 15 days and sectioned for electron microscopy by conventional methods.Cells of this species possess a multilayered outer envelope, and the external cell surface is differentiated into ridges extending parallel or obliquely to the long axis of the cell.Cells from very young cultures resemble non-photosynthetic bacteria and contain only a granular cytoplasm, scattered high-density particles, and lowdensity areas corresponding to the chromatin areas observed by light microscopy. They contain neither the chromatophores nor the lame]lar systems assumed by previous investigators to be characteristic of this species when grown anaerobically in the light.Chromatophores appear in cells from cultures older than about 12 hours, while systems of paired lamellae appear along with the chromatophores in cells from cultures older than about 8 days. Divergent opinions concerning the occurrence of chromatophores or lamellae in this species can be resolved on the basis of the age of cultures used in previous studies.Other changes occurring in ceils from cultures of increasing age include the appearance of granular and reticulate cytoplasmic bodies and vacuoles, extension of the chromatin areas, and the appearance of a single membrane enclosing several chromatophores.

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Section: Discussionsupporting

confidence: 81%

The Structure of Rhodospirillum rubrum

Hickman

Frenkel

1959

The Journal of Cell Biology

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“…In figure 14, an isthmus of nuclear material connects the two larger masses of nuclear material in a cell which is incompletely compartmented by the centripetally growing membrane septum. Such a disposition of the nuclear material is strikingly remindful of the classical figures of amitosis, such as those of Nowikoff (1910), and of the electron micrograph of Bradfield (1954) showing nuclear division in a staphylococcus. It should be noted that Bradfield described his figure as one representing amitosis.…”

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confidence: 65%

Electron Microscopy of Ultrathin Sections of Bacteria Iii

Chapman

1959

J Bacteriol

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“…'Silver-Feulgen' method (based on a technique of Bradfield, 1954; see also Jurand, Deutsch & Dunn, 1959). After osmic fixation for 1 hr.…”

Section: Methodsmentioning

confidence: 99%

Structure of the Mate-Killer (mu) particles in Paramecium aurelia, stock 540

Beale

Jurand

1960

Journal of General Microbiology

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SUMMARYThe mate-killer (mu) particles in the cytoplasm of Paramecium aurelia, stock 540, variety (syngen) 1, were studied by : Feulgen-staining ; phase-contrast microscopy ; fluorescence under ultraviolet irradiation after staining with acridine orange ; electron microscopy (including the ' silver-Feulgen ' technique). The appearance of the particles following treatment with DNAase and RNAase was observed. It was found that the mu particles were capsulated rod-shaped structures, 2-lop long and about 0 . 3 ,~ in diameter (excluding the capsule); they appeared to reproduce by transverse fission without formation of cross-walls. There was an external double membrane and the internal material consisted largely of DNA, which was not limited to particular zones but spread throughout the interior of the particle. RNA was also present, The relationships of the particles to other micro-organisms is discussed, and it is concluded that they do not differ from bacteria in any important respect.

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Electron Microscopic Observations on Bacterial Nuclei

Cited by 44 publications

References 4 publications

The Structure of Rhodospirillum rubrum

The Structure of Rhodospirillum rubrum

Electron Microscopy of Ultrathin Sections of Bacteria Iii

Structure of the Mate-Killer (mu) particles in Paramecium aurelia, stock 540

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