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Functional ultrastructure of the plant nucleolus

Nucleoli are nuclear domains present in almost all eukaryotic cells. They not only specialize in the production of ribosomal subunits but also play roles in many fundamental cellular activities. Concerning ribosome biosynthesis, particular stages of this process, i.e., ribosomal DNA transcription, p...

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Autor principal: Stępiński, Dariusz
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Springer Vienna 2014
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4209244/
https://www.ncbi.nlm.nih.gov/pubmed/24756369
http://dx.doi.org/10.1007/s00709-014-0648-6
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author Stępiński, Dariusz
author_facet Stępiński, Dariusz
author_sort Stępiński, Dariusz
collection PubMed
description Nucleoli are nuclear domains present in almost all eukaryotic cells. They not only specialize in the production of ribosomal subunits but also play roles in many fundamental cellular activities. Concerning ribosome biosynthesis, particular stages of this process, i.e., ribosomal DNA transcription, primary RNA transcript processing, and ribosome assembly proceed in precisely defined nucleolar subdomains. Although eukaryotic nucleoli are conservative in respect of their main function, clear morphological differences between these structures can be noticed between individual kingdoms. In most cases, a plant nucleolus shows well-ordered structure in which four main ultrastructural components can be distinguished: fibrillar centers, dense fibrillar component, granular component, and nucleolar vacuoles. Nucleolar chromatin is an additional crucial structural component of this organelle. Nucleolonema, although it is not always an unequivocally distinguished nucleolar domain, has often been described as a well-grounded morphological element, especially of plant nucleoli. The ratios and morphology of particular subcompartments of a nucleolus can change depending on its metabolic activity which in turn is correlated with the physiological state of a cell, cell type, cell cycle phase, as well as with environmental influence. Precise attribution of functions to particular nucleolar subregions in the process of ribosome biosynthesis is now possible using various approaches. The presented description of plant nucleolar morphology summarizes previous knowledge regarding the function of nucleoli as well as of their particular subdomains not only in the course of ribosome biosynthesis.
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spelling pubmed-42092442014-10-31 Functional ultrastructure of the plant nucleolus Stępiński, Dariusz Protoplasma Review Article Nucleoli are nuclear domains present in almost all eukaryotic cells. They not only specialize in the production of ribosomal subunits but also play roles in many fundamental cellular activities. Concerning ribosome biosynthesis, particular stages of this process, i.e., ribosomal DNA transcription, primary RNA transcript processing, and ribosome assembly proceed in precisely defined nucleolar subdomains. Although eukaryotic nucleoli are conservative in respect of their main function, clear morphological differences between these structures can be noticed between individual kingdoms. In most cases, a plant nucleolus shows well-ordered structure in which four main ultrastructural components can be distinguished: fibrillar centers, dense fibrillar component, granular component, and nucleolar vacuoles. Nucleolar chromatin is an additional crucial structural component of this organelle. Nucleolonema, although it is not always an unequivocally distinguished nucleolar domain, has often been described as a well-grounded morphological element, especially of plant nucleoli. The ratios and morphology of particular subcompartments of a nucleolus can change depending on its metabolic activity which in turn is correlated with the physiological state of a cell, cell type, cell cycle phase, as well as with environmental influence. Precise attribution of functions to particular nucleolar subregions in the process of ribosome biosynthesis is now possible using various approaches. The presented description of plant nucleolar morphology summarizes previous knowledge regarding the function of nucleoli as well as of their particular subdomains not only in the course of ribosome biosynthesis. Springer Vienna 2014-04-23 2014 /pmc/articles/PMC4209244/ /pubmed/24756369 http://dx.doi.org/10.1007/s00709-014-0648-6 Text en © The Author(s) 2014 https://creativecommons.org/licenses/by/4.0/ Open Access This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited.
spellingShingle Review Article
Stępiński, Dariusz
Functional ultrastructure of the plant nucleolus
title Functional ultrastructure of the plant nucleolus
title_full Functional ultrastructure of the plant nucleolus
title_fullStr Functional ultrastructure of the plant nucleolus
title_full_unstemmed Functional ultrastructure of the plant nucleolus
title_short Functional ultrastructure of the plant nucleolus
title_sort functional ultrastructure of the plant nucleolus
topic Review Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4209244/
https://www.ncbi.nlm.nih.gov/pubmed/24756369
http://dx.doi.org/10.1007/s00709-014-0648-6
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