scholarly journals The Nuclear Family: Functional Organization of the Cell Nucleus Prague, Czech Republic, May 5–8, 2006

2006 ◽  
Vol 174 (4) ◽  
pp. 478-479
Author(s):  
Nicole LeBrasseur
Keyword(s):  
Czech Republic ◽  
Cell Nucleus ◽  
Functional Organization ◽  
Nuclear Family

Organization of transcription and pre-mRNA splicing within the mammalian cell nucleus

1995 ◽  
Vol 53 ◽  
pp. 768-769
Author(s):  
D.L. Spector ◽  
S. Huang ◽  
S. Kaurin
Keyword(s):  
Rna Polymerase Ii ◽  
Cell Nucleus ◽  
Functional Organization ◽  
Mrna Splicing ◽  
Splicing Factors ◽  
Interchromatin Granule Clusters ◽  
Interchromatin Granule ◽  
Nuclear Regions ◽  
Relationship Of ◽  
Perichromatin Fibrils

We have been interested in the organization of RNA polymerase II transcription and pre-mRNA splicing within the cell nucleus. Several models have been proposed for the functional organization of RNA within the eukaryotic nucleus and for the relationship of this organization to the distribution of pre-mRNA splicing factors. One model suggests that RNAs which must be spliced are capable of recruiting splicing factors to the sites of transcription from storage and/or reassembly sites. When one examines the organization of splicing factors in the nucleus in comparison to the sites of chromatin it is clear that splicing factors are not localized in coincidence with heterochromatin (Fig. 1). Instead, they are distributed in a speckled pattern which is composed of both perichromatin fibrils and interchromatin granule clusters. The perichromatin fibrils are distributed on the periphery of heterochromatin and on the periphery of interchromatin granule clusters as well as being diffusely distributed throughout the nucleoplasm. These nuclear regions have been previously shown to represent initial sites of incorporation of 3H-uridine.

Immunolocalization of nuclear antigens in cryofixed cells which have been prepared by molecular distillation drying or freeze-substitution

1990 ◽  
Vol 48 (3) ◽  
pp. 898-899
Author(s):  
David L. Spector ◽  
Robert J. Derby
Keyword(s):  
Cell Nucleus ◽  
Molecular Distillation ◽  
Functional Organization ◽  
Freeze Substitution ◽  
3 Dimensional ◽  
Small Nuclear Ribonucleoprotein ◽  
Nuclear Antigens ◽  
Dimensional Reconstruction ◽  
Nuclear Regions ◽  
Immunoperoxidase Labeling

Studies in our laboratory are involved in evaluating the structural and functional organization of the mammalian cell nucleus. Since several major classes (U1, U2, U4/U6, U5) of small nuclear ribonucleoprotein particles (snRNPs) play a crucial role in the processing of pre-mRNA molecules, we have been interested in the localization of these particles within the cell nucleus. Using pre-embedding immunoperoxidase labeling combined with 3-dimensional reconstruction, we have recently shown that nuclear regions enriched in snRNPs form a reticular network within the nucleoplasm which extends between the nucleolar surface and the nuclear envelope. In the present study we were inte rested in extending these nuclear localizations using cell preparation techniques which avoid slow penetration of fixatives, chemical crosslinking of potential antigens and solvent extraction. CHOC 400 cells were cryofixed using a CF 100 ultra rapid cooling device (LifeCell Corp.). After cryofixation cells were molecular distillation dried, vapor osmicated, in filtra ted in 100% Spurr resin in vacuo and polymerized in molds a t 60°C. Using this procedure we were able to evaluate the distribution of snRNPs in resin embedded cells which had not been chemically fixed, incubated in cryoprotectants or extracted with solvents.

scholarly journals Involvement of nuclear lamins in postmitotic reorganization of chromatin as demonstrated by microinjection of lamin antibodies.

1986 ◽  
Vol 103 (5) ◽  
pp. 1847-1854 ◽  
Author(s):  
R Benavente ◽  
G Krohne
Keyword(s):  
Immunoelectron Microscopy ◽  
Cell Nucleus ◽  
Nuclear Membrane ◽  
Functional Organization ◽  
Nuclear Lamina ◽  
Condensed State ◽  
Interphase Chromatin ◽  
Nuclear Lamins ◽  
Architectural Framework

The nuclear lamins are major components of a proteinaceous polymer that is located at the interface of the nuclear membrane and chromatin; these lamins are solubilized and dispersed throughout the cytoplasm during mitosis. It has been postulated that these proteins, assembled into the lamina, provide an architectural framework for the organization of the cell nucleus. To test this hypothesis we microinjected lamin antibodies into cultured PtK2 cells during mitosis, thereby decreasing the soluble pool of lamins. The antibody injected was identified, together with the lamins, in cytoplasmic aggregates by immunoelectron microscopy. We show that microinjected cells are not able to form normal daughter nuclei, in contrast to cells injected with other immunoglobulins. Although cells injected with lamin antibodies are able to complete cytokinesis, the chromatin of their daughter nuclei remains arrested in a telophase-like configuration, and the telophase-like chromatin remains inactive as judged from its condensed state and by the absence of nucleoli. These results indicate that lamins and the nuclear lamina structure are involved in the functional organization of the interphase chromatin.

scholarly journals An eclipse over the cell nucleus Functional organization of the cell nucleus Prague, August 9-12, 1999

2000 ◽  
Vol 19 (15) ◽  
pp. 3843-3848 ◽  
Author(s):  
I. Raška ◽  
U. Aebi ◽  
W.C. Earnshaw
Keyword(s):  
Cell Nucleus ◽  
Functional Organization

scholarly journals Ultrastructural cytochemistry as a tool for studying transcriptional mechanisms

2015 ◽  
Author(s):  
Davide Basello ◽  
Barbara Cisterna ◽  
Valentina Galimberti ◽  
Valentina Poletto ◽  
Marco Biggiogera
Keyword(s):  
Cell Nucleus ◽  
Functional Organization ◽  
Electron Tomography ◽  
Biological Processes ◽  
Cytochemical Localization ◽  
Ultrastructural Cytochemistry ◽  
Immunocytochemical Techniques ◽  
Microscopy Techniques ◽  
Very High

Ultrastructural cytochemistry is a powerful tool for investigating the biology of the cell nucleus. Thanks to its very high resolution, it has been possible to localize with extreme accuracy the sites of transcription, splicing and maturation of both mRNA and rRNA, their precise location as well as their movements. By means of immunocytochemical techniques, many nuclear proteins have been given a specific role in the transcriptional mechanisms, with the possibility of precisely mapping their location on a single RNA fibril. Starting from the 70s, the techniques have evolved from the resolution of autoradiography to that of gold-coupled antibodies, reaching a resolution of few nanometers. The use of correlative microscopy techniques as well as of electron tomography has also allowed the 3D imaging of ribonucleoprotein-containing structures in situ, in the nucleus. The association of a biological mechanism with the cytochemical localization of a specific molecule has been crucial in defining the functional organization of the cell nucleus, and has been invaluable for the understanding of many biological processes.

scholarly journals The Interchromatin Compartment Participates in the Structural and Functional Organization of the Cell Nucleus

BioEssays ◽  
2020 ◽  
Vol 42 (2) ◽  
pp. 1900132 ◽  
Author(s):  
Thomas Cremer ◽  
Marion Cremer ◽  
Barbara Hübner ◽  
Asli Silahtaroglu ◽  
Michael Hendzel ◽  
...  
Keyword(s):  
Cell Nucleus ◽  
Functional Organization ◽  
Interchromatin Compartment
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