WordNet

the approximate amount of something (usually used prepositionally as in `in the region of' (同)neighborhood
the extended spatial location of something; "the farming regions of France"; "religions in all parts of the world"; "regions of outer space" (同)part
a knowledge domain that you are interested in or are communicating about; "it was a limited realm of discourse"; "here we enter the region of opinion"; "the realm of the occult" (同)realm
a large indefinite location on the surface of the Earth; "penguins inhabit the polar regions"
arrange by systematic planning and united effort; "machinate a plot"; "organize a strike"; "devise a plan to take over the directors office" (同)organise, prepare, devise, get_up, machinate
cause to be structured or ordered or operating according to some principle or idea (同)organise
bring order and organization to; "Can you help me organize my files?" (同)organise, coordinate
a person who brings order and organization to an enterprise; "she was the organizer of the meeting" (同)organiser, arranger
someone who enlists workers to join a union (同)organiser, labor organizer
a small round body of protein in a cell nucleus; such organelles contain RNA and are involved in protein synthesis (同)nucleole

PrepTutorEJDIC

(地理的な)『地域』,『地帯』;(特に広大な)地方 / 《複数形で》(宇宙などの)区分,界,属 / (身体の)部分 / (学問などの)分野,領域 / 《複数形で》(都会から離れた)地方
組織者;設立者;(組合の)オルグ
(細胞核内の)小核,核仁

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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2014/04/23 10:43:43」(JST)

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The nucleolus organizer region (NOR) or nucleolar organizer is a chromosomal region around which the nucleolus forms. This region is the particular part of a chromosome that is associated with a nucleolus after the nucleus divides. The region contains several tandem copies of ribosomal DNA genes. In humans, the NOR contains genes for 5.8S, 18S, and 28S rRNA clustered on the short arms of chromosomes 13, 14, 15, 21 and 22 (the acrocentric chromosomes).

Nucleolus organizer regions (NORs) are head-to-tail arrays of genes encoding the precursor of the three largest ribosomal RNAs (18S, 5.8S and 25S in plants). NORs include active rRNA genes, which give rise to secondary constrictions of metaphase chromosomes, and silent rRNA genes, which are often highly compacted in dense heterochromatin. At metaphase, a proteinaceous remnant of the nucleolus often remains associated with the secondary constriction. Each rRNA gene at a NOR is nearly identical in sequence, although variation in size due to differences in the number of repeated DNA elements in the intergenic spacer region is common.^[1]

In complete chromosome complements there were always 6 chromosomes with a terminal Nucleolus organizing region (NOR). In most cases part of the NOR was decondensed, and several of this decondensed areas formed together a big collecting nucleolus (Ger. Sammelnukleolus). This collecting nucleolus was easily visible in phase contrast even without pretreatment due to its large size and particular structure. The shape of the collecting nucleolus ranged from nearly circular to irregular. Instead of just one collecting nucleolus of 6 NOR there were also several smaller collecting nucleoli made up from the NORs of only 2 to 5 nucleolus organizing chromosomes.^[2]

Evaluation of nucleolar organizer region-associated proteins in breast malignancy. Nucleolus organizer regions (NORs) have been identified by means of an argyrophilic technique (Ag-NOR) in routinely processed, formalin-fixed paraffin sections of breast lesions. This method reveals NORs as black dots in the nuclei of cells, by virtue of the argyrophilia of NOR-associated proteins. The number of Ag-NORs has been thought to be related to cellular activation and has recently been applied to non-Hodgkin’s lymphomas and melanocytic skin lesions. It was found in the present study that the total number of Ag-NORs in malignant breast lesions significantly exceeded those of normal breast and benign lesions. The number of clumps of Ag-NORs, however, were not useful discriminators. Neither numbers of total Ag-NORs nor of clumps of Ag-NORs correlate with mitotic counts and it may be that their numbers relate to ploidy. It is suggested that the Ag-NOR technique will find increasing application as an adjunct to diagnostic histopathology.^[3]

In karyotype analysis, a silver stain can be used to identify the NOR.^[4]^[5] Silver nitrate inserts into the NOR-associated protein in the stalks and satellites, staining the proteins dark black. The amount of stain deposited and the number of NORs differs among the population, although the cell should normally have a maximum of 10 NORs per cell.

Several genes are located at the NOR, including RUNX2,^[6] UBTF,^[7] and APC^[8] genes.

Discovery

Barbara McClintock first described the "nucleolar-organizing body" in Zea mays in 1934.^[9]^[10]

References

^ Craig S Pikaard. The epigenetic of nucleolar dominance. doi:10.1016/S0168-9525(00)02113-2.
^ Mario Nenno. Phaseolus polytene chromosomes.
^ R. Smith, J. Crocker. Evaluation of nucleolar organizer region-associated proteins in breast malignancy. doi:10.1111/j.1365-2559.1988.tb01923.x. Retrieved 18 March 2014.
^ Bloom SE, Goodpasture C. (1976). "An improved technique for selective silver staining of Nucleolar Organizer Regions in human chromosomes". Human Genetics 34 (2): 199–206. PMID 63440.
^ Lay YF, Pfeiffer RA, Arrighi FE, Hsa TC (1978). "Combination of silver and fluorescent staining for metaphase chromosomes". American Journal of Human Genetics 30 (1): 76–79. PMC 1685453. PMID 74950.
^ Young DW, Hassan MQ, Pratap J, Galindo M, Zaidi SK, Lee S, Yang X, Xie R, Javed A, Underwood JM, Furcinitti P, Imbalzano AN, Penman S, Nickerson JA, Montecino MA, Lian JB, Stein JL, van Wijnen AJ, Stein GS (2007). "Mitotic occupancy and lineage-specific transcriptional control of rRNA genes by Runx2". Nature 445 (7126): 442–446. doi:10.1038/nature05473. PMID 17251981.
^ Chan EKL, Imai H, Hamel JC, Tan EM (1991). "Human autoantibody to RNA polymerase I transcription factor hUBF: molecular identity of nucleolus organizer region autoantigen NOR-90 and ribosomal RNA transcription upstream binding factor". Journal of Experimental Medicine 174 (5): 1239–1244. doi:10.1084/jem.174.5.1239. PMC 2119007. PMID 1940801.
^ Tischfield JA, Shao C (2003). "Somatic recombination redux". Nature Genetics 33 (1): 5–6. doi:10.1038/ng0103-5. PMID 12509771.
^ McClintock B (1934). "The relation of a particular chromosomal element to the development of the nucleoli in Zea mays". Zeitschrift fur Zellforschung und mikroskopische Anatomie 21 (2): 294–328. doi:10.1007/BF00374060.
^ "Dr. Barbara McClintock, 90, Gene Research Pioneer, Dies". New York Times. 1992-09-04.

UpToDate Contents

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1. 様々な抗核抗体 miscellaneous antinuclear antibodies
2. 松果体部腫瘍 pineal gland masses
3. 免疫グロブリンの構造 structure of immunoglobulins
4. 慢性骨髄性白血病の分子遺伝学 molecular genetics of chronic myeloid leukemia
5. 血液悪性腫瘍およびリンパ悪性腫瘍の遺伝的異常 genetic abnormalities in hematologic and lymphoid malignancies

English Journal

Intra-generic and interspecific karyotype patterns of Leptodactylus and Adenomera (Anura, Leptodactylidae) with inclusion of five species from Central Amazonia.

Coelho AC1,2, de Mattos TL3, Viana P3, Terencio ML4, Schneider CH5, Menin M5, Gross MC5.
Genetica.Genetica.2015 Dec 9. [Epub ahead of print]
The genera Leptodactylus and Adenomera comprise 92 species distributed throughout the Neotropical region. These species have a modal diploid chromosome number 2n = 22. However, chromosome rearrangements are evident in the differentiation of five intra-generic groups in the genus Leptodactylus (L.
PMID 26650375

Digital image analysis of AgNORs in cervical smears of women with premalignant and malignant lesions of the uterine cervix.

García-Vielma C1, Dávila-Rodríguez MI1, Hernández-Garza F2, Cerda-Flores RM3, Cortés-Gutiérrez EI1.
Biotechnic & histochemistry : official publication of the Biological Stain Commission.Biotech Histochem.2015 Nov 3:1-6. [Epub ahead of print]
We performed a hospital-based, unmatched case-control study to investigate the association between progressive stages of cervical neoplasia and digital analysis of cell proliferation by silver stained nucleolus organizer region associated proteins (AgNORs). We measured cell proliferation levels in t
PMID 26528580

A high-resolution physical map integrating an anchored chromosome with the BAC physical maps of wheat chromosome 6B.

Kobayashi F1, Wu J2,3, Kanamori H4, Tanaka T5, Katagiri S6, Karasawa W7, Kaneko S8, Watanabe S9, Sakaguchi T10, Hanawa Y11, Fujisawa H12, Kurita K13, Abe C14, Iehisa JC15, Ohno R16, Šafář J17, Šimková H18, Mukai Y19, Hamada M20, Saito M21, Ishikawa G22, Katayose Y23, Endo TR24, Takumi S25, Nakamura T26, Sato K27, Ogihara Y28, Hayakawa K29, Doležel J30, Nasuda S31, Matsumoto T32, Handa H33.
BMC genomics.BMC Genomics.2015 Aug 12;16:595. doi: 10.1186/s12864-015-1803-y.
BACKGROUND: A complete genome sequence is an essential tool for the genetic improvement of wheat. Because the wheat genome is large, highly repetitive and complex due to its allohexaploid nature, the International Wheat Genome Sequencing Consortium (IWGSC) chose a strategy that involves constructing
PMID 26265254