Zur Struktur des Nucleolus

Lettré, Renate; Siebs, Wilhelmine

doi:10.1007/bf00628889

Cited by 26 publications

(4 citation statements)

References 3 publications

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“…There is certainly no lack of histochemical evidence in the literature indicating the presence of DNA in nucleoli (30)(31)(32)(33)(34). The vermiform internal structure of the nucleolus, first described by Estable and Sotelo (35), and recently studied by electron microscopy (36)(37)(38), has been stated to be Feulgen-positive by Lettr6 and Siebs (39).…”

Section: Discussionmentioning

confidence: 99%

Isolation and Properties of Liver Cell Nucleoli

Monty

Litt

Kay

et al. 1956

The Journal of Cell Biology

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1. The significance of the term nucleolus has been discussed. 2. A detailed method for the isolation of nucleoli from already isolated rat or cat liver nuclei has been presented. 3. The presence of DNA in isolated liver cell nucleoli has been indicated by histochemical methods. 4. The percentages of DNA and RNA in the isolated nucleoli have been determined by chemical analysis. 5. The specific activities of aldolase, arginase, and catalase have been determined for two subnuclear fractions and for the isolated nucleoli of rat and cat liver, and the relative amounts of these enzymes in the same subnuclear fractions and nucleoli of rat liver have been measured. 6. The significance of the above findings has been discussed and consideration has been given to what types of isolated nuclei might best serve as starting material for the isolation of nucleoli. 7. A new hypothesis has been presented that nucleoli of the liver cell type may function primarily in furnishing (directly or indirectly) templates for the synthesis of the particular enzymes that must govern the chemistry of mitosis.

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Section: Discussionmentioning

confidence: 99%

Isolation and Properties of Liver Cell Nucleoli

Monty

Litt

Kay

et al. 1956

The Journal of Cell Biology

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“…They described an Ag-positive network of fibrils, which they called a "nucleonema" (see E stable, 1966). Lettré and her coworker described this network as consisting of Ag-stained small granules but stressed the point that the "backbone" of this network was the NOR's of the chromo somes (see L ettré and Siebs, 1954;L ettré et al, 1966). This view, which was also supported by electron-microscopic observations on Ag-stained nucleoli, is quite in agreement with our results, except that we find it likely that the chromosomal component remains unstained by Ag.…”

Section: Discussionmentioning

confidence: 99%

The nature of the Ag-staining of nucleolus organizer regions

Schwarzacher¹,

Mikelsaar²,

Schnedl³

1978

Cytogenet Genome Res

233

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Electron micrographs reveal that the Ag-stainable substance is located on the outside of NOR’s or around them but not in the chromosomes themselves. In association figures, the Ag-positive material lies between the acrocentric chromosomes. Light-microscopic studies show that the Ag stainability of the nucleolus in interphase is correlated with the function of the NOR, as seen from inactive and activated lymphocytes. Much more Ag-positive material is seen in prophase than in meta- and anaphase. It starts to increase again in late telophase. In male meiosis the NOR’s remain Ag-positive until pachytene. First and second metaphase figures are negative. Experiments using RNase, TCA, and trypsin indicate that the Ag-stainable substance is an acidic protein. The precipitation of Ag granules in interphase nuclei seen in the electron microscope is greatest over the fibrillar component of the nucleolus. The most likely interpretation is that the Ag-stainable material is a component of ribonucleic protein accumulating around active NOR’s. In mitosis some of this material remains at the NOR’s. In first meiosis it is completely removed before diakinesis.

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“…Early cytochemical studies based on light microscopy techniques showed the presence of DNA within the nucleolonema several times, either by the Feulgen reaction [33,34] or by autoradiography [15,16]. The localization of DNA by the Feulgen reaction remained controversial [34].…”

Section: Animal Cellsmentioning

confidence: 99%

“…In most cases, however, the filamentous structure are detected in animal material (chick embryo cells or rat cells) only after drug application (adenosine or analogous, DR.B) [15,16,21,33,34,48], or the suppression of one element of the culture medium (arginine) [20], and in plant cells after the treatment of isolated nuclei with a detergent [30,31]. For example, in phase contrast microscopy, one can observe that within 2 or 3 rain of treatment of isolated nuclei with Tween-80, nucleoli of plant cells unfold into filamentous structures or nucleolonemata.…”

Section: Introductionmentioning

confidence: 99%

The nucleolonema of plant and animal cells: a comparison

Deltour¹,

Motté²

1990

Biology of the Cell

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Summary -Depending on the author and the animal or plant origin of the material under study, the term "nucleolonema" is used in different contexts and thus indicates nucleolar ultrastructures that are different. In this paper, we attempt to clarify this state of affairs and to propose a definition for the plant cell nucleolonema nucleolonema / nucleolus / fibrillar centre / dense fibrillar component / rDNA

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Zur Struktur des Nucleolus

Cited by 26 publications

References 3 publications

Isolation and Properties of Liver Cell Nucleoli

Isolation and Properties of Liver Cell Nucleoli

The nature of the Ag-staining of nucleolus organizer regions

The nucleolonema of plant and animal cells: a comparison

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