Does the synthesis of ribosomal RNA take place within nucleolar fibrillar centers or dense fibrillar components? A critical appraisal
Language English Country United States Media print
Document type Journal Article, Research Support, Non-U.S. Gov't
PubMed
7772414
DOI
10.1006/jsbi.1995.1001
PII: S1047-8477(85)71001-5
Knihovny.cz E-resources
- MeSH
- Affinity Labels MeSH
- Models, Biological MeSH
- Bromodeoxyuridine metabolism MeSH
- Cell Nucleolus metabolism ultrastructure MeSH
- 3T3 Cells metabolism ultrastructure MeSH
- PC12 Cells metabolism ultrastructure MeSH
- Chromatin ultrastructure MeSH
- DNA Topoisomerases, Type I metabolism MeSH
- Microscopy, Electron MeSH
- Transcription, Genetic MeSH
- HeLa Cells metabolism ultrastructure MeSH
- In Situ Hybridization MeSH
- Microscopy, Immunoelectron MeSH
- Immunohistochemistry MeSH
- DNA, Single-Stranded analysis MeSH
- Rats MeSH
- Cells, Cultured MeSH
- Humans MeSH
- Mice MeSH
- DNA, Ribosomal genetics MeSH
- RNA, Ribosomal biosynthesis MeSH
- RNA Polymerase I metabolism MeSH
- Animals MeSH
- Check Tag
- Rats MeSH
- Humans MeSH
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- Affinity Labels MeSH
- Bromodeoxyuridine MeSH
- Chromatin MeSH
- DNA Topoisomerases, Type I MeSH
- DNA, Single-Stranded MeSH
- DNA, Ribosomal MeSH
- RNA, Ribosomal MeSH
- RNA Polymerase I MeSH
The localization of transcribing rRNA genes within nucleoli of mammalian cells, although intensively studied, has not been established. Most published papers on this topic situate transcribing ribosomal genes either to nucleolar fibrillar centers or to nucleolar dense fibrillar components. To clarify this point, we have generated the electron microscopic affinity cytochemistry picture of the nucleolus of cultured mammalian cells. Three kinds of affinity probes have been used: (1) probes to nucleolar chromatin, including rDNA sequences; (2) probes to a number of macromolecules (such as RNA polymerase I) which are directly, or indirectly, involved in the synthesis and processing of rRNA and formation of preribosomes; (3) antibodies to bromouridine for a recently standardized nonisotopical method depicting incorporated bromouridine within RNA. The results suggest the localization of transcription sites not only to dense fibrillar components but also to the border region between these components and fibrillar centers. Our data support a hypothesis that in metabolically active mammalian nucleoli, fibrillar centers and dense fibrillar components form a single functional domain for the transcription of rRNA genes, with nascent transcripts generating "automatically" dense fibrillar components. Through the active process of transcription, individual rRNA genes thus become engulfed within dense fibrillar components.
References provided by Crossref.org
Fluctuations of pol I and fibrillarin contents of the nucleoli
Reproduction of the FC/DFC units in nucleoli
Nucleolar DNA: the host and the guests
Structure and epigenetics of nucleoli in comparison with non-nucleolar compartments
Pontin is localized in nucleolar fibrillar centers
Immuno-electron localization of DNA in chondriolites of Saccharomyces cerevisiae mitochondria
