Etude ultrastructurale des modifications nucléolaires au cours des processus d'enkystement et de dékystement d'Acanthamoeba castellanii

in Biology of the Cell (1988), 63

Ultrastructural and cytochemical study on nucleolus in rat oocytes using RNase gold complex

in Biology of the Cell (1987), 60

Postembedding immunoelectron microscopic studies on Ehrlich tumour cell nucleoli

Poster (1987)

Le nucléole : un organite cellulaire fondamental

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

Behaviour of nucleolus during mitosis. A comparative ultrastructural study of various cancerous cell lines using the Ag-NOR staining procedure.

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 ▲]

The nucleus and the nucleolar organizer regions. Collective review edited by S.Fakan and D. Hernandez-Verdun. Part 2A: Organization, distribution and transcriptional activity of rDNA in animal cells

in Biology of the Cell (1986), 56

Antinucleolar autoantibodies: ultrastructural localization of antigens on HEp 2 cells

Poster (1986)

Ultrastructure of HEp 2 cells

in Peeters, H (Ed.) Protides of the Biological Fluids (1986)

The fibrillar centres and their relationships with the other nucleolar components

Poster (1985)

Re-evaluation of the site of transcription in Ehrlich tumour cell nucleoli.

in Biology of the Cell (1985), 54(1), 57-64

Recent electron microscopic immunolocalization studies (Scheer and Rose, 1984) indicated that RNA polymerase I is located in, and probably confined to, the fibrillar centres of the nucleoli. This ... [more ▼]

Recent electron microscopic immunolocalization studies (Scheer and Rose, 1984) indicated that RNA polymerase I is located in, and probably confined to, the fibrillar centres of the nucleoli. This conclusion appears to be in contradiction to previous autoradiographic studies reporting that transcription of rRNA genes takes place in the dense fibrillar component. Despite the fact that rRNA transcription occurs in the dense fibrillar component of Ehrlich tumour cell nucleoli, we show in the present paper that dense fibrillar component containing rapidly labelled RNA can be visualized not only around but also inside the fibrillar centres. [less ▲]