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Nucleolar chromatin

About: Nucleolar chromatin is a research topic. Over the lifetime, 170 publications have been published within this topic receiving 6776 citations.


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Journal ArticleDOI
TL;DR: A hypothesis for chemical carcinogen induced condensation of nuclear and nucleolar chromatin is proposed and it is believed to be a result of cascade effects initiated by the inhibition of messenger RNA synthesis after exposure tochemical carcinogen in vivo.
Abstract: A hypothesis for chemical carcinogen induced condensation of nuclear and nucleolar chromatin is proposed. Chromatin condensation is believed to be a result of cascade effects initiated by the inhibition of messenger RNA synthesis after exposure to chemical carcinogen in vivo. Inhibition of messenger RNA synthesis leads to the loss of protein production, which in turn causes the dephosphorylation of histone H1 and triggers the condensation of chromatin in vivo.

5 citations

Journal ArticleDOI
TL;DR: DNA replication was investigated in nucleoli isolated from Ehrlich ascites tumor cells and addition of exogenous DNA to the reaction mixture significantly stimulated [ 3 H]dTMP incorporation.

4 citations

Journal ArticleDOI
TL;DR: The intranucleolar chromatin has been detected by feeding HeLa cells with bromodeoxyuridine and then using an immunocytochemical technique for its detection at the ultrastructural level and labelling was mainly observed on the dense fibrillar component (DFC), which surrounds the fibrilar centres (FC).

4 citations

Book ChapterDOI
TL;DR: A correlative light and electron microscopy (CLEM) protocol allowing detection of tagged-Pol I by fluorescent microscopy and high-resolution imaging of the nucleolar ultrastructural context is described, which can be implemented in laboratories equipped with conventional fluorescence and electrons and does not require sophisticated "pipeline" for imaging.
Abstract: Nucleoli form around RNA polymerase I transcribed ribosomal RNA (rRNA) genes. The direct electron microscopy observation of rRNA genes after nucleolar chromatin spreading (Miller's spreads) constitutes to date the only system to quantitatively assess transcription at a single molecule level. However, the spreading procedure is likely generating artifact and despite being informative, these spread rRNA genes are far from their in vivo situation. The integration of the structural characterization of spread rRNA genes in the three-dimensional (3D) organization of the nucleolus would represent an important scientific achievement. Here, we describe a correlative light and electron microscopy (CLEM) protocol allowing detection of tagged-Pol I by fluorescent microscopy and high-resolution imaging of the nucleolar ultrastructural context. This protocol can be implemented in laboratories equipped with conventional fluorescence and electron microscopes and does not require sophisticated "pipeline" for imaging.

4 citations

Journal Article
TL;DR: In this article, the spatial distribution of nucleolar chromatin bodies in the macronucleus of D.nasutum nucleoli was studied using 3D reconstructions based on serial ultrathin sections.
Abstract: We have earlier shown that the typical Didinium nasutum nucleolus is a complex convoluted branched domain, comprising a dense fibrillar component located at the periphery of the nucleolus and a granular component located in the central part. Here our main interest was to study quantitatively the spatial distribution of nucleolar chromatin structures in these convoluted nucleoli. There are no \"classical\" fibrillar centers in D.nasutum nucleoli. The spatial distribution of nucleolar chromatin bodies, which play the role of nucleolar organizers in the macronucleus of D.nasutum, was studied using 3D reconstructions based on serial ultrathin sections. The relative number of nucleolar chromatin bodies was determined in macronuclei of recently fed, starved D.nasutum cells and in resting cysts. This parameter is shown to correlate with the activity of the nucleolus. However, the relative number of nucleolar chromatin bodies in different regions of the same convoluted nucleolus is approximately the same. This finding suggests equal activity in different parts of the nucleolar domain and indicates the existence of some molecular mechanism enabling it to synchronize this activity in D. nasutum nucleoli. Our data show that D. nasutum nucleoli display bipartite structure. All nucleolar chromatin bodies are shown to be located outside of nucleoli, at the periphery of the fibrillar component.

4 citations

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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20211
20202
20195
20183
20171
20161