| 词条 | Nucleolus organizer region |
| 释义 |
] Nucleolus organiser regions (NORs) are chromosomal regions crucial for the formation of the nucleolus. In humans, the NORs are located on the short arms of the acrocentric chromosomes 13, 14, 15, 21 and 22, the genes RNR1, RNR2, RNR3, RNR4, and RNR5 respectively.[1] These regions code for 5.8S, 18S, and 28S ribosomal RNA.[1] The NORs are "sandwiched" between the repetitive, heterochromatic DNA sequences of the centromeres and telomeres.[1] The exact sequence of these regions is not included in the human reference genome as of 2016[1] or the GRCh38.p10 released January 6, 2017.[2] However, it is known that NORs contain tandem copies of ribosomal DNA (rDNA) genes.[1] Some sequences of flanking sequences proximal and distal to NORs have been reported.[3] The NORs of a loris have been reported to be highly variable.[4] There are also DNA sequences related to rDNA that are on other chromosomes and may be involved in nucleoli formation.[5]Visualization] Barbara McClintock first described the "nucleolar-organizing body" in Zea mays in 1934.[6] In karyotype analysis, a silver stain can be used to identify the NOR.[7][8] NORs can also be seen in nucleoli using silver stain, and that is being used to investigate cancerous changes.[9][10][11] NORs can also be seen using antibodies directed against the protein UBF, which binds to NOR DNA.[1]Molecular biologyIn addition to UBF, NORs also bind to ATRX protein, treacle, sirtuin-7 and other proteins.[1] UBF has been identified as a mitotic "bookmark" of expressed rDNA, which allows it to resume transcription quickly after mitosis.[1] The distal flanking junction (DJ) of the NORs has been shown to associate with the periphery of nucleoli.[3] rDNA operons in Escherichia coli have been found to cluster near each other, similar to a eukaryotic nucleolus.[12] See also
References1. ^1 2 3 4 5 6 7 {{cite journal | vauthors = McStay B | title = Nucleolar organizer regions: genomic 'dark matter' requiring illumination | journal = Genes & Development | volume = 30 | issue = 14 | pages = 1598–610 | year = 2016 | pmid = 27474438 | pmc = 4973289 | doi = 10.1101/gad.283838.116 | url = }} {{organelles}}{{Nucleus}}{{DEFAULTSORT:Nucleolus Organizer Region}}2. ^{{cite web|last1=anon|title=Human Genome Overview|url=https://www.ncbi.nlm.nih.gov/grc/human|website=ncbi.nlm.nih.gov/|publisher=Genome Reference Consortium|accessdate=17 June 2017}} 3. ^1 {{cite journal | vauthors = Floutsakou I, Agrawal S, Nguyen TT, Seoighe C, Ganley AR, McStay B | title = The shared genomic architecture of human nucleolar organizer regions | journal = Genome Research | volume = 23 | issue = 12 | pages = 2003–12 | year = 2013 | pmid = 23990606 | pmc = 3847771 | doi = 10.1101/gr.157941.113 | url = }} 4. ^{{cite journal | vauthors = Baicharoen S, Hirai Y, Srikulnath K, Kongprom U, Hirai H | title = Hypervariability of Nucleolus Organizer Regions in Bengal Slow Lorises, Nycticebus bengalensis (Primates, Lorisidae) | journal = Cytogenetic and Genome Research | volume = 149 | issue = 4 | pages = 267–273 | year = 2016 | pmid = 27648559 | doi = 10.1159/000449145 | url = }} 5. ^{{cite journal | vauthors = Kupriyanova NS, Netchvolodov KK, Sadova AA, Cherepanova MD, Ryskov AP | title = Non-canonical ribosomal DNA segments in the human genome, and nucleoli functioning | journal = Gene | volume = 572 | issue = 2 | pages = 237–42 | year = 2015 | pmid = 26164756 | doi = 10.1016/j.gene.2015.07.019 | url = }} 6. ^{{cite journal | vauthors = McClintock B | title = The relation of a particular chromosomal element to the development of the nucleoli in Zea mays | journal = Zeitschrift für Zellforschung und Mikroskopische Anatomie | volume = 21 | issue = 2 | pages = 294–328 | year = 1934 | doi = 10.1007/BF00374060 }} 7. ^{{cite journal | vauthors = Bloom SE, Goodpasture C | title = An improved technique for selective silver staining of nucleolar organizer regions in human chromosomes | journal = Human Genetics | volume = 34 | issue = 2 | pages = 199–206 | date = October 1976 | pmid = 63440 | doi = 10.1007/bf00278889 }} 8. ^{{cite journal | vauthors = Lau YF, Pfeiffer RA, Arrighi FE, Hsu TC | title = Combination of silver and fluorescent staining for metaphase chromosomes | journal = American Journal of Human Genetics | volume = 30 | issue = 1 | pages = 76–9 | date = January 1978 | pmid = 74950 | pmc = 1685453 }} 9. ^{{cite journal | vauthors = Stepan A, Simionescu C, Pirici D, Ciurea R, Margaritescu C | title = Fractal analysis and the diagnostic usefulness of silver staining nucleolar organizer regions in prostate adenocarcinoma | journal = Analytical Cellular Pathology (Amsterdam) | volume = 2015 | issue = | pages = 250265 | year = 2015 | pmid = 26366372 | pmc = 4558419 | doi = 10.1155/2015/250265 | url = }} 10. ^{{cite journal | vauthors = Gundog M, Yildiz OG, Imamoglu N, Aslan D, Aytekin A, Soyuer I, Soyuer S | title = Prognostic Significance of Two Dimensional AgNOR Evaluation in Local Advanced Rectal Cancer Treated with Chemoradiotherapy | journal = Asian Pacific Journal of Cancer Prevention : APJCP | volume = 16 | issue = 18 | pages = 8155–61 | year = 2015 | pmid = 26745054 | doi = | url = }} 11. ^{{cite journal | vauthors = Sowmya GV, Nahar P, Astekar M, Agarwal H, Singh MP | title = Analysis of silver binding nucleolar organizer regions in exfoliative cytology smears of potentially malignant and malignant oral lesions | journal = Biotechnic & Histochemistry | volume = 92 | issue = 2 | pages = 115–121 | year = 2017 | pmid = 28296547 | doi = 10.1080/10520295.2017.1283055 | url = }} 12. ^{{cite journal | vauthors = Gaal T, Bratton BP, Sanchez-Vazquez P, Sliwicki A, Sliwicki K, Vegel A, Pannu R, Gourse RL | title = Colocalization of distant chromosomal loci in space in E. coli: a bacterial nucleolus | journal = Genes & Development | volume = 30 | issue = 20 | pages = 2272–2285 | year = 2016 | pmid = 27898392 | pmc = 5110994 | doi = 10.1101/gad.290312.116 | url = }} 3 : Cell anatomy|Molecular genetics|Nuclear substructures |
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