The correlation between the growth of the cell and nucleolar secretion in Basidiobolus ranarum eidam

Soudek, D.

doi:10.1016/0014-4827(60)90173-7

Cited by 14 publications

(9 citation statements)

References 5 publications

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“…Many authors believe that nucleolar vacuoles are indicative of metabolic activity within the nucleolus (DERMEN 1933;SERRA 1959;SouDEK 1960;CHOUINARD 1964CHOUINARD , 1966JoHNSON 1969;JoHNSON and JoNES 1967). Their evidence is that in cells that are not growing vacuoles are absent from the nucleolus, but are present in those of growing cells.…”

Section: Discussionmentioning

confidence: 99%

“…This dynamic aspect is probably the key to understanding their relation to nucleolar activity. SouDEK ( 1960) believes that the discharge of vacuolar contents occurs when inflow of material into the vacuole exceeds outflow by diffusion. If the contents of the vacuoles are products of nucleolar metabolism, then the rate at which the nucleolar vacuole completes its cycle of growth may be a reliable guide to nucleolar activity.…”

Section: Discussionmentioning

confidence: 99%

“…Many observations on nucleolar vacuoles suggest that they are related to, and are expressions of, the physiological activity of the nucleolus (LUEHR 1928;DERMEN 1933;HoPKER 1953;SERRA 1959;SouDEK 1960;KoRDAN and MoRGENSTERN 1962). These suggestions are strengthened by two findings: JoHNSON ( 1969) shows that in cultured cells of tobacco, nucleoli with vacuoles incorporate more H 3 -uridine than nucleoli that lack them: ZYBINA ( 1968) shows that nucleoli of developing mouse oocytes become vacuolated at the same time as they become able to incorporate H 3 -uridine.…”

Section: Introductionmentioning

confidence: 99%

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Vacuoles in the Nucleoli ofZea MaysRoot Apices and their Possible Significance in Nucleolar Physiology

Barlow

1970

Caryologia

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Vacuoles in the Nucleoli ofZea MaysRoot Apices and their Possible Significance in Nucleolar Physiology

Barlow

1970

Caryologia

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“…X 68,000. the observed similarities in uhrastructure between the spherules and the fibrillar zones of the nucleolus (Figs. 14 and 20) as well as from reports that vacuoles and amorphous substances (31)(32)(33)(34) are extruded from the nucleolus in animal and plant cells. Our own data do not demonstrate unequivocally that the spherules seen in Allium cepa, Vicia faba, and Rhaphanus sativus actually originate from the nucleolar mass.…”

Section: Fmcae 19mentioning

confidence: 92%

A LIGHT AND ELECTRON MICROSCOPE STUDY OF SMALL, SPHERICAL NUCLEAR BODIES IN MERISTEMATIC CELLS OF ALLIUM CEPA, VICIA FABA, AND RAPHANUS SATIVUS

Lafontaine

1965

The Journal of Cell Biology

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A B S T R A C TInterphase, preprophase, and prophase nuclei of meristematic cells of AUium ¢epa, Vide faba, and Raphanus sativus are characterized by the presence of spherical bodies approximately 1 /~ in diameter. These structures are Feulgen-negative but stain metachromatlcaUy with azure B, as the nucleolus, following fixation with glutaraldehyde. At the ultrastructural level, they consist predominantly of fibrils estimated to be between 70 and 100 A in diameter which greatly resemble those found within certain zones of the nucleolus in these plant species. Moreover, in Allium ¢epa, these spherules often exhibit dense particles which are also found within the fibrillar zones of the nucleolus in this species. The observations that the bodies in question are frequently located at the surface of the nucleolus and moreover show cytochemical and ultrastructural similarities with this organelle suggest that they may originate from the nucleolus. However, the common association of the spherules with chromosome strands may indicate instead that these bodies represent extranucleolar ribonucleoprotein materials synthesized by specific chromosomal loci. I N T R O D U C T I O NIn the course of an earlier electron microscope study (1) of nuclear structures in meristematic cells of Allium cepa and Vicia faba, spherical bodies, approximately 2 /z in diameter, were observed at interphase. These structures were lighter than either the chromosomes or the nucleolus under electron microscopy, but stained metachromatically with azure B, as the nucleolus, following fixation with formalin. Since then, nuclear bodies of a similar appearance have been noted in Tetrahymena pyriformis (2,3), in kidney (4, 5), and thymus (6).The purpose of the present paper is to describe in more detail the distribution of these bodies during interphase, preprophase, and prophase and to report certain characteristics which they share with the nucleolus. M A T E R I A L A N D M E T H O D SRoots of Allium cepa grown in distilled water and of Vicia faba and Raphanus sativus L. grown in damp vermiculite were used for the present study. Portions 0.5 to 1 mm in length were excised from the root tips and fixed in the following solutions: (a) 1 per cent osmium tetroxide in distilled water (7), (b) 1 per cent osmium tetroxide buffered with Veronal (8) or phosphate (9) to a pH of 7.3, (c) 4 per cent formaldehyde or glutaraldehyde. Other roots were fixed in one of these aldehydes and postfixed in 1 per cent osmium tetroxide (10). Following dehydration in alcohol the specimens were embedded in Epon 812. Sections 0.25 to 0.75 D thick were stained with Feulgen and methylene blue (11); ultrathin sections were stained with solutions of heavy metals (12, 13). Electron micrographs were obtained with a Siemens on

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“…It would therefore seem more likely that these vacuoles contain nucleolar material in a dispersed form rather than elements of the nuclear sap as previously suggested (20). Such fluid-filled intranucleolar vacuoles are thought to form as a result of the physiological activity of the nucleolar mass and to be extruded from time to time into the surrounding nucleoplasm (22)(23)(24).…”

Section: Structural Components Of the Nucleolus At Preprophasementioning

confidence: 99%

A CORRELATED LIGHT AND ELECTRON MICROSCOPE STUDY OF THE NUCLEOLAR MATERIAL DURING MITOSIS IN VICIA FABA

Lafontaine

Chouinard

1963

The Journal of Cell Biology

160

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Root meristematic cells of Viola faba were examined, with both light and electron microscopes, in order to study the behaviour of the nucleolar material during the mitotic process. Under light microscopy, the preprophase nucleolus is seen to consist of a densely stained material in which are embedded several unstained vacuole-like structures of varying size. The electron microscope reveals that the dense nucleolar material is formed of two struc turally distinct components, each segregated into irregularly shaped zones blending with one another. One of these components is represented by 150 A granules which, in places, are arranged into thread-like structures approximately 0.1 # in diameter; the other component apparently consists of fibrils 60 to 100 A in diameter. The large and medium sized intranucleolar vacuoles contain loosely scattered granules and fibrils similar to those just described. The granular and fibrillar components of the denser portion of the nucleolus persist as such during prophase and disperse throughout the nuclear cavity at the time of nucleolar disintegration. After nuclear membrane breakdown, these granules and fibrils, as well as those of the nucleoplasm, mix freely with similar elements already present within the forming spindle. No evidence has been obtained that, during or after nucleolar disintegration, the structural components of the nucleolus become associated as such with the chromosomes to form an external or internal matrix. Our observations suggest the existence, of a matrix substance within late prophase, metaphase, and anaphase chromosomes, the fine structure of which bears strong resemblance to that of their constituent coiled chromonemata. Data are presented, moreover, that indicate that part of this matrix substance, presumably formed at some time during prophase, is released from the chromosomes during their anaphasic movement. A number of observations indicate that the main bulk of the next nucleolus is derived from a prenucleolar fibrillogranular material, arranged into thread-like structures some 0.1 # in diameter, which collect in the interchromosomal spaces during early and midtelophase. Finally, our data would seem to favour the view that most of this prenucleolar material results from a resumption of the synthetic activity of the early and midtelophase chromosomes rather than from a mere shedding of a preexisting matrix substance.

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The correlation between the growth of the cell and nucleolar secretion in Basidiobolus ranarum eidam

Cited by 14 publications

References 5 publications

Vacuoles in the Nucleoli ofZea MaysRoot Apices and their Possible Significance in Nucleolar Physiology

Vacuoles in the Nucleoli ofZea MaysRoot Apices and their Possible Significance in Nucleolar Physiology

A LIGHT AND ELECTRON MICROSCOPE STUDY OF SMALL, SPHERICAL NUCLEAR BODIES IN MERISTEMATIC CELLS OF ALLIUM CEPA, VICIA FABA, AND RAPHANUS SATIVUS

A CORRELATED LIGHT AND ELECTRON MICROSCOPE STUDY OF THE NUCLEOLAR MATERIAL DURING MITOSIS IN VICIA FABA

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