Behaviour of nucleolus during mitosis

Ploton, Dominique; Thiry, Marc; Ménager, M.; Lepoint, A; Adnet, J. J.; Goessens, Guy

doi:10.1007/bf00332182

Cited by 59 publications

(17 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Tau-1 reactivity in telophase was coincident with the prenucleolar bodies of the re-forming nucleolus (Fig. le), presumably due to their association with the NORs (28,29).…”

Section: Methodsmentioning

confidence: 86%

Identification of nuclear tau isoforms in human neuroblastoma cells.

Loomis

Howard

Castleberry

et al. 1990

Proc. Natl. Acad. Sci. U.S.A.

185

187

View full text Add to dashboard Cite

The X proteins have been reported only in association with microtubules and with ribosomes in situ, in the normal central nervous system. In addition, T has been shown to be an integral component of paired helical rdaments, the principal constituent of the neurofibriflary tangles found in brains of patients with Alzheimer disease and of most aged individuals with Down syndrome (trisomy 21). We report here the localization of the well-characterized Tau-1 monoclonal antibody to the nucleolar organizer regions of the acrocentric chromosomes and to their interphase counterpart, the fibrillar component of the nucleolus, in human neuroblastoma cells. Similar localization to the nucleolar organizer regions was also observed in other human cell lines and in one monkey kidney cell line but was not seen in non-primate species. Immunochemically, we further demonstrate the existence of the entire Tmolecule in the isolated nuclei of neuroblastoma cells. Nuclear 7 proteins, like the 7 proteins of the paired helical filaments, cannot be extracted in standard SDS-containing electrophoresis sample buffer but require pretreatment with formic acid prior to immunoblot analysis. This work indicates that 7 may function in processes not directly associated with microtubules and that highly insoluble complexes of T may also play a role in normal cellular physiology.T proteins were first identified as a family of phosphoproteins that associate with microtubules in vivo and stimulate their assembly in vitro (1, 2). Recent evidence indicates that T proteins are an integral component of the paired helical filaments, the principal constituent of the neurofibrillary tangles characteristic ofAlzheimer disease or senile dementia of the Alzheimer type (3-7). The structure of the 7 gene and of the cDNAs cloned and sequenced from the expressed mRNAs reveals a tripartite protein composed of a variable N-terminal domain, a constant central domain, and a C-terminal, tubulin-binding domain (8,9). Hence, it appears that much of the observed electrophoretic heterogeneity is generated by alternative splicing of a single RNA transcript (8-10).Initially, r was reported to be restricted to axons within the central nervous system (11). A more widespread distribution was subsequently documented, indicating the presence of T along microtubules of both the axonal and somatodendritic compartments (12). Additionally, T was observed on ribosomes in neuronal somatodendritic compartments and in glial cells (12). We report here the localization of the Tau-1 monoclonal antibody (11) to the nucleolar organizer regions (NORs) of the acrocentric chromosomes (nos. 13, 14, 15, 21, and 22), in cultured human cells. Immunolocalization is also detected in the interphase counterpart of the NORs, the fibrillar component of nucleoli. Similar localization patterns are observed in cultured monkey kidney cells but are not present in non-primate cultured cell lines. The presence of T is biochemically documented in the isolated nuclei of two human neuroblastoma cell lines. ...

show abstract

“…Tau-1 reactivity in telophase was coincident with the prenucleolar bodies of the re-forming nucleolus (Fig. le), presumably due to their association with the NORs (28,29).…”

Section: Methodsmentioning

confidence: 86%

Identification of nuclear tau isoforms in human neuroblastoma cells.

Loomis

Howard

Castleberry

et al. 1990

Proc. Natl. Acad. Sci. U.S.A.

185

187

View full text Add to dashboard Cite

show abstract

“…, 1986Moreno et al 1990;Pession et al 1991), the behavior of the nucleolus during mitosis (Moreno Dfaz de la Espina et ai. 1976;Hernandez-Verdun et al 1980;Paweletz and Risuefio 1982;Hernandez-Verdun and Derenzini 1983;Medina et al 1983Medina et al , 1986Ploton et al 1987) and the identity and functional role played by key nucleolar proteins (Lischwe etal. 1979(Lischwe etal.…”

Section: Introductionmentioning

confidence: 94%

Microwave irradiation improvements in the silver staining of the nucleolar organizer (Ag-NOR) technique

Medina

Cerdido

Marco

1995

Histochem Cell Biol

View full text Add to dashboard Cite

The well-known technique of silver staining of the nucleolar organizer (Ag-NOR) is improved in contrast, selectivity and speed when performed with microwave irradiation. The Ag-NOR technique is a very useful tool for studies on the functional morphology and molecular architecture of the nucleolus, and is reputed to be one of the best techniques for diagnosis and prognosis of cancer lesions. To test the generality of the enhancing effects, our study has involved the use of both mammalian and plant cells. Two steps in the process are improved quantitatively by microwave irradiation: fixation and staining itself. Fixation with the ethanol-based reagent, Kryofix, for 3 min in the microwave oven, resulted in good structural preservation at the optical level, and enhanced the contrast and selectivity of silver staining. On the contrary, we found that neither glutaraldehyde fixation, nor a treatment of sections with Carnoy's solution, improved Ag-NOR staining. After an analysis of the effects of the different substances involved in sample preparation, we conclude that ethanol is an essential factor for fixation for nucleolar staining, particularly if aldehydes are eliminated from fixative solutions. The process of staining was performed with a drop of staining solution on a semithin section of plastic-embedded tissue in the microwave oven for 1 min. Staining under these conditions always improved the visualization of nucleoli, regardless of the fixation procedure. Therefore, microwave irradiation at both steps is recommended for giving the best results. Microwave irradiation probably enhances fixation by controlled heat, whereas the increase in reactivity of the staining solution is a direct effect by the microwaves on the silver ions themselves. We used this method to study nucleolar materials during mitosis in proliferating plant cells. Current applications of Ag-NOR staining can be improved with this technical modification.

show abstract

“…First, genetic, morphological and cytochemical investigations have led to the conclusion that PNBs and NORs are composed of RNA and rDNA, respectively (Ritossa and Spiegelman, 1965). More recently, cytochemical and immunocytochemical approaches have revealed that PNBs contain specific nucleolar proteins such as fibrillarin (Ochs et al, 1985a,b;Jimenez-Garcia et al, 1989), B23/NO38 (nucleophosmin) (Ochs et al, 1985b;Schmidt-Zachmann et al, 1987), C23 (nucleolin) (Ochs et al, 1985b;Pfeifle et al, 1986), and the 180-kDa protein from Xenopus (Bell et al, 1992), as well as argyrophilic proteins (Ochs et al, 1985a,b;Ploton et al, 1987;JimenezGarcia et al, 1989). In addition, Azum-Gelade et al (1994) have localized U3 snRNA in PNBs in Chinese hamster ovary (CHO) cells.…”

Section: Introductionmentioning

confidence: 99%

Nucleologenesis: U3 snRNA-containing prenucleolar bodies move to sites of active pre-rRNA transcription after mitosis.

Jiménez‐García

Segura-Valdéz

Ochs

et al. 1994

MBoC

150

View full text Add to dashboard Cite

We have investigated the distribution of U3 snRNA and rRNA in HeLa cells and normal rat kidney cells during interphase and mitosis. U3 snRNA, known to be involved in prerRNA processing, was detected in nucleoli and coiled bodies during interphase, whereas rRNA was distributed in the nucleoli and throughout the cytoplasm. By comparison, ribosomal protein S6 was detected in nucleoli, coiled bodies, and in the cytoplasm. During nucleologenesis, pre-rRNA was observed in newly forming nucleoli during late telophase but not in prenucleolar bodies (PNBs), whereas U3 snRNA was detected in forming nucleoli and PNBs. Similar findings to those reported here for the localization of U3 snRNA have been reported previously for the U3 small nuclear ribonucleoprotein fibrillarin. These results suggest that components involved in pre-rRNA processing localize to discrete PNBs at the end of mitosis. The nucleolus is formed at specific telophase domains (nucleolar organizing regions) and the PNBs, containing factors essential for pre-rRNA processing, are recruited to these sites of rRNA transcription and processing. INTRODUCTIONThe nucleolus is a well defined intranuclear organelle where the synthesis and processing of pre-rRNA and preribosome assembly occurs (for a review see Busch and Smetana, 1970;Hadjiolov, 1985;Scheer and Benavente, 1990). Upon transcription of the tandemly arranged rDNA genes located in the nucleolus of mammalian cells, pre-rRNA molecules (45S) are produced that undergo a series of specific cleavages to give rise to 28S, 5.8S, and 18S rRNAs that are present in mature cytoplasmic ribosomes (Perry, 1976;Hadjiolov, 1985). In this process, U3 small nuclear ribonucleoprotein particles (snRNP) have been implicated in one of the earliest

show abstract

Behaviour of nucleolus during mitosis

Cited by 59 publications

References 31 publications

Identification of nuclear tau isoforms in human neuroblastoma cells.

Identification of nuclear tau isoforms in human neuroblastoma cells.

Microwave irradiation improvements in the silver staining of the nucleolar organizer (Ag-NOR) technique

Nucleologenesis: U3 snRNA-containing prenucleolar bodies move to sites of active pre-rRNA transcription after mitosis.

Contact Info

Product

Resources

About