References of "Thiry, Marc"
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See detailLocalization of DNA within Ehrlich tumour cell nucleoli by immunoelectron microscopy.
Thiry, Marc ULg; Scheer, U.; Goessens, Guy ULg

in Biology of the Cell (1988), 63(1), 27-34

The distribution of DNA in Ehrlich tumour cell nucleoli was investigated by means of an immunocytochemical approach involving a monoclonal antibody directed against double- and single-stranded DNA ... [more ▼]

The distribution of DNA in Ehrlich tumour cell nucleoli was investigated by means of an immunocytochemical approach involving a monoclonal antibody directed against double- and single-stranded DNA. Immunolabelling was performed either before or after the embedding process. The postembedding labelling method allows better ultrastructural preservation than the preembedding labelling method. In particular, the various nucleolar components are well preserved and identifiable. In the nucleolus, labelling is particularly concentrated over the perinucleolar chromatin and over its intranucleolar invaginations, which penetrate the nucleolar body and often terminate at the fibrillar centres. In addition, aggregates of gold particles are found in the fibrillar centres, preferentially towards the peripheral regions. By contrast, the dense fibrillar component is completely devoid of labelling. The results seem to indicate that DNA containing the rDNA genes is located in the fibrillar centres, with a preference for the peripheral regions. This finding suggests that transcription of the rDNA genes should occur within the confines of the fibrillar centre, probably close to the boundary region of the surrounding dense fibrillar component. The results are discussed in the light of present knowledge of the functional organization of the nucleolus. [less ▲]

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See detailComparative study of the condensation of chicken erythrocyte and calf thymus chromatins by di- and multivalent cations.
Marquet, R.; Colson, Pierre ULg; Matton, Anne-Marie ULg et al

in Journal of Biomolecular Structure & Dynamics (1988), 5(4), 839-57

The condensation of chicken erythrocyte (CE) and calf thymus (CT) chromatins upon addition of di- and multivalent cations has been studied using turbidity, precipitation and electric dichroism ... [more ▼]

The condensation of chicken erythrocyte (CE) and calf thymus (CT) chromatins upon addition of di- and multivalent cations has been studied using turbidity, precipitation and electric dichroism measurements. For all the cations investigated (Mg2+, Tb3+, Co(NH3)6(3+), spermidine Spd2+ and spermine Sp4+) condensation of CE chromatin occurred before the onset of aggregation, while aggregation of CT chromatin started before condensation with all cations except Mg2+ and Tb3+. Precipitation of CE chromatin required lower di- and multivalent cations concentrations than CT chromatin. The electric dichroism data for both chromatins, at low ionic strength in the absence of di- or multivalent cations, indicated that the nucleoprotein molecules were not totally decondensed but that a "precondensed" state was already present. A positive electric dichroism was observed for the most condensed chromatin fibers, in agreement with the "cross-linker" models. Tb3+ led to less compact condensed particles as judged from the electric dichroism observations, but electron microscopy revealed that "30 nm fibers" were formed. Very little aggregation was produced by Tb3+. On the contrary, spermine produced very large networks of condensed molecules, but large spheroidal particles were also observed. The condensation of CE chromatin happened without changes of solution conductivity upon cation salt addition, regardless of the condensing cation, indicating a cooperative uptake of the ions during this process. [less ▲]

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See detailImmunoelectron microscope localization of bromodeoxyuridine incorporated into DNA of Ehrlich tumor cell nucleoli.
Thiry, Marc ULg

in Experimental Cell Research (1988), 179(1), 204-13

The distribution of DNA within the nucleolus of Ehrlich tumor cells has been investigated by means of a recent immunocytochemical approach involving an electron microscopic detection of incorporated 5 ... [more ▼]

The distribution of DNA within the nucleolus of Ehrlich tumor cells has been investigated by means of a recent immunocytochemical approach involving an electron microscopic detection of incorporated 5-bromodeoxyuridine (BUdR) into DNA by an anti-BUdR monoclonal antibody. An immunogold method has been performed on ultrathin sections of cells embedded in Lowicryl K4M. In the nucleolus, gold particles are essentially found over the perinucleolar chromatin adn over its intranucleolar invaginations which are connected with the fibrillar centers. In addition, a few gold particles are also observed in the fibrillar centers, preferentially toward their peripheral regions. In contrast, the dense fibrillar component is completely devoid of labeling. The results are discussed in the context of other recent findings concerning the functional organization of the nucleolus. [less ▲]

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See detailStudy of RNA distribution in the nucleolar components of Ehrlich cell using RNase-gold method.
Thiry, Marc ULg

in Histochemistry (1988), 89(3), 231-6

The RNA distribution in Ehrlich tumour cell nucleoli has been investigated using RNase-gold method. This technique has been applied to sections of cells prepared under various fixation and embedding ... [more ▼]

The RNA distribution in Ehrlich tumour cell nucleoli has been investigated using RNase-gold method. This technique has been applied to sections of cells prepared under various fixation and embedding conditions. As expected, the specificity and intensity of labelling by gold particles have varied according to the experimental conditions used. Interestingly, however, it has been noted that the localization of gold particles does also vary and in particular within the fibrillar centre. This observation underlines the interest of assaying the RNase-gold complex under various conditions. The gold particles were particularly concentrated over the granular component and to a lesser extent, in the dense fibrillar component. In the latter constituent, it has been noted that the gold markers were preferentially localized at the edge of the dense fibrils. Surprisingly, a few gold particles have also been detected in the fibrillar centres. The weak labelling has persisted even after pepsin or DNase extraction but has completely disappeared after RNase extraction. Further, an inhibition of rRNA synthesis by a treatment with actinomycin D has not produced a significant decrease of the number of gold particles present in the fibrillar centre. These results suggest that fibrillar centres contain a small amount of RNA which would not correspond to pre-rRNA. [less ▲]

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See detailImmunoelectron microscopic study of nucleolar DNA during mitosis in Ehrlich tumor cells.
Thiry, Marc ULg; Scheer, U.; Goessens, Guy ULg

in European Journal of Cell Biology (1988), 47(2), 346-57

In order to investigate the DNA localization within Ehrlich tumor cell nucleoli during mitosis, two recent immunocytochemical methods using either an anti-DNA or an anti-bromodeoxyuridine (BrdU ... [more ▼]

In order to investigate the DNA localization within Ehrlich tumor cell nucleoli during mitosis, two recent immunocytochemical methods using either an anti-DNA or an anti-bromodeoxyuridine (BrdU) monoclonal antibody have been applied. In both cases, the immunogold labeling has been performed on ultrathin sections of cells embedded either in Lowicryl K4M or in Epon, respectively. Identical results are observed with both immunocytochemical approaches. In the interphase nucleolus, besides the labeling of the perinucleolar chromatin shell and of its intranucleolar invaginations which penetrate into the nucleolar body and often terminate at the fibrillar centers, a few gold particles are also preferentially found towards the peripheral region of the fibrillar centers. In contrast, the dense fibrillar component and the granular component are never labeled. During mitosis, the fibrillar centers persist at the chromosomal nucleolus organizing regions (NOR's) and can be selectively stained by the silver method. However, these metaphase fibrillar centers are no longer decorated by the DNA- or BrdU antibodies. These results indicate that until the end of prophase, rRNA genes are present inside the fibrillar center material, disappear during metaphase and reappear in reconstituting nucleoli during telophase. Thus, fibrillar centers appear to represent structures sui generis, which are populated by rRNA genes only when the nucleolus is functionally active. In segregated nucleoli after actinomycin D treatment, the DNA labeling is exclusively restricted to the perinucleolar chromatin blocks. These findings also suggest that the DNA content of the fibrillar center material varies according to the rRNA transcription level of the cells. The results are discussed in the light of the present knowledge of the functional organization of the nucleolus. [less ▲]

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See detailEtude cytochimique et immunocytochimique du nucléole
Thiry, Marc ULg

Scientific conference (1987)

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See detailUltrastructure of nucleolus organizing regions in Ehrlich tumour cells
Thiry, Marc ULg

in Biology of the Cell (1987), 60

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See detailUltrastructural and cytochemical study on nucleolus in rat oocytes using RNase gold complex
Antoine, Nadine ULg; Thiry, Marc ULg; Baeckeland, E et al

in Biology of the Cell (1987), 60

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See detailAnti SSA and anti SSB autoantibodies: an immunofluorescence, ultrastructural and immunoblotting study
Thiry, Marc ULg; Vigneron, Alain; Humbel, René et al

Poster (1987)

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See detailLe nucléole : un organite cellulaire fondamental
Lepoint, Alain; Goessens, Guy ULg; Thiry, Marc ULg

in Revue de l'Association Belge des Technologies de Laboratoire (1987), 14

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See detailRelations between nucleoli and nucleolus-organizing regions during the cell cycle
Goessens, Guy ULg; Thiry, Marc ULg; Lepoint, Alain

in Chromosomes Today (1987), 9

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See detailUltrastructural and cytochemical study of nucleoli of Ehrlich tumour cell using a RNase gold complex
Thiry, Marc ULg

in Micron and Microsc. Acta (1987), 18

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See detailBehaviour of nucleolus during mitosis. A comparative ultrastructural study of various cancerous cell lines using the Ag-NOR staining procedure.
Ploton, D.; Thiry, Marc ULg; Menager, M. et al

in Chromosoma (1987), 95(2), 95-107

The aim of the present work was to study the distribution and the behaviour of the silver-staining nucleolar organizer region (Ag-NOR) proteins at the ultrastructural level during interphase and mitosis ... [more ▼]

The aim of the present work was to study the distribution and the behaviour of the silver-staining nucleolar organizer region (Ag-NOR) proteins at the ultrastructural level during interphase and mitosis in five human and murine cancerous cell lines each characterized by a typical nucleolar morphology. During interphase the Ag-NOR proteins are restricted to the fibrillar centres (F.C.) and/or to the dense fibrillar component (D.F.C.). During prophase the silver-staining components come into close contact with some chromosomes and are arranged with a typical polarity: chromosome, F.C. and D.F.C. Then F.C. and D.F.C. together form roundish silver-stained structures and integrate in part within indentations at the periphery of the metaphase chromosomes. During anaphase and telophase large and small spherical silver-staining structures may be seen. They correspond respectively to the metaphase NORs and to numerous structures which appear de novo within ribonucleoprotein (RNP) material localized between the chromosomes. During late telophase the number of the small silver-staining structures decreases whereas the size of the larger ones increases. Then the interphase nucleoli recover their typical shape. These results suggest that when rRNA synthesis is impaired during mitosis the inactive NORs assume a structure and a localization which are not typical of the cell line. In contrast the F.C. and D.F.C. are probably two aspects of the NORs whose typical distribution, relative to the other nucleolar components, gives the interphasic nucleolus its characteristic morphology. [less ▲]

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See detailUltrastructural localisation of AG NOR proteins during interphase and mitosis in human or mouse cancerous cells
Ploton, Dominique; Thiry, Marc ULg; Menager, Monique et al

in Acta Biologica Hungarica (1986), 37

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See detailEssais de localisation des RNA polymérases dans des cellules tumorales d'Ehrlich par immunocytochimie ultrastructurale
Thiry, Marc ULg; Hendrick, J C; Lepoint, Alain et al

in Biology of the Cell (1986), 57

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See detailEtude immunocytochimique ultrastructurale de cellules tumorales d'Ehrlich à l'aide d'anticorps dirigés contre la RNA polymérase d'E. Coli
Thiry, Marc ULg; Hendrick, J C; Lepoint, Alain et al

in Bulletin de l'Association des Anatomistes (1986), 70

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