The chromosome region which is active in nucleolus formation and which functions in the synthesis of ribosomal RNA.
Within most types of eukaryotic CELL NUCLEUS, a distinct region, not delimited by a membrane, in which some species of rRNA (RNA, RIBOSOMAL) are synthesized and assembled into ribonucleoprotein subunits of ribosomes. In the nucleolus rRNA is transcribed from a nucleolar organizer, i.e., a group of tandemly repeated chromosomal genes which encode rRNA and which are transcribed by RNA polymerase I. (Singleton & Sainsbury, Dictionary of Microbiology & Molecular Biology, 2d ed)
The use of silver, usually silver nitrate, as a reagent for producing contrast or coloration in tissue specimens.
The most abundant form of RNA. Together with proteins, it forms the ribosomes, playing a structural role and also a role in ribosomal binding of mRNA and tRNAs. Individual chains are conventionally designated by their sedimentation coefficients. In eukaryotes, four large chains exist, synthesized in the nucleolus and constituting about 50% of the ribosome. (Dorland, 28th ed)
DNA sequences encoding RIBOSOMAL RNA and the segments of DNA separating the individual ribosomal RNA genes, referred to as RIBOSOMAL SPACER DNA.
In a prokaryotic cell or in the nucleus of a eukaryotic cell, a structure consisting of or containing DNA which carries the genetic information essential to the cell. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)
Cells in certain regions of an embryo that self-regulate embryonic development. These organizers have been found in dorsal and ventral poles of GASTRULA embryos, including Spemann organizer in amphibians, and Hensen node in chicken and mouse. These organizer cells communicate with each other via a network of secreted signaling proteins, such as BONE MORPHOGENETIC PROTEINS and their antagonists (chordin and noggin).
Mapping of the KARYOTYPE of a cell.
The phase of cell nucleus division following PROMETAPHASE, in which the CHROMOSOMES line up across the equatorial plane of the SPINDLE APPARATUS prior to separation.
Silver. An element with the atomic symbol Ag, atomic number 47, and atomic weight 107.87. It is a soft metal that is used medically in surgical instruments, dental prostheses, and alloys. Long-continued use of silver salts can lead to a form of poisoning known as ARGYRIA.
Goosecoid protein is a homeodomain protein that was first identified in XENOPUS. It is found in the SPEMANN ORGANIZER of VERTEBRATES and plays an important role in neuronal CELL DIFFERENTIATION and ORGANOGENESIS.
A silver salt with powerful germicidal activity. It has been used topically to prevent OPHTHALMIA NEONATORUM.

Ectopic NORs on human chromosomes 4qter and 8q11: rare chromosomal variants detected in two families. (1/367)

Two different NOR bearing non-acrocentric chromosomes were detected during prenatal diagnosis performed on two probands because of advanced maternal age. In the first case, a chromosome 4 carried a NOR in the telomeric region of the long arm (4qs), while in the second case a NOR was inserted into chromosome 8q11. Family analysis showed the variant chromosomes to be transmitted through at least three generations in each family. There were no reports of reproductive problems or phenotypic effects in the carriers of these chromosomes, indicating the benign character of the aberrant chromosomes. In order to characterise the chromosomal variants more precisely, various differential banding techniques were applied.  (+info)

Cell cycle-dependent regulation of RNA polymerase I transcription: the nucleolar transcription factor UBF is inactive in mitosis and early G1. (2/367)

Transcription of ribosomal RNA genes by RNA polymerase (pol) I oscillates during the cell cycle, being maximal in S and G2 phase, repressed during mitosis, and gradually recovering during G1 progression. We have shown that transcription initiation factor (TIF)-IB/SL1 is inactivated during mitosis by cdc2/cyclin B-directed phosphorylation of TAFI110. In this study, we have monitored reactivation of transcription after exit from mitosis. We demonstrate that the pol I factor UBF is also inactivated by phosphorylation but recovers with different kinetics than TIF-IB/SL1. Whereas TIF-IB/SL1 activity is rapidly regained on entry into G1, UBF is reactivated later in G1, concomitant with the onset of pol I transcription. Repression of pol I transcription in mitosis and early G1 can be reproduced with either extracts from cells synchronized in M or G1 phase or with purified TIF-IB/SL1 and UBF isolated in the presence of phosphatase inhibitors. The results suggest that two basal transcription factors, e.g., TIF-IB/SL1 and UBF, are inactivated at mitosis and reactivated by dephosphorylation at the exit from mitosis and during G1 progression, respectively.  (+info)

Colchicine therapy for hepatic murine schistosomal fibrosis: image analysis and serological study. (3/367)

Colchicine in a dose of 200 micrograms kg body weight/day (5 days/week) was administered to groups of Schistosoma mansoni infected mice 12 weeks post infection, either alone or following previous praziquantel therapy at the 8th week of infection. Certain groups received colchicine for 6 weeks and others received it for 10 weeks. Colchicine alone did not significantly change the light microscopic appearance of schistosomal liver fibrosis, or hepatic collagen content estimated histomorphometrically, and did not reduce the elevated IL-2 serum level. Colchicine induced hepatic injury consisted of intense inflammatory reaction in granuloma and portal tracts, hepatocytic degeneration, and elevation of serum AST and ALT levels. Colchicine seemed to postpone granulomatous reaction healing and collagen deposition rather than inhibiting collagen formation or degrading it. Colchicine inhibited proliferation of hepatocytes of infected mice by expanding G2-M phases of cell cycle, thus reduced Ag NOR count and raised cell ploidy and cyclic AMP serum level. Subsidence of schistosomal infection by praziquantel prior to colchicine therapy greatly reduced inflammatory cellular reaction, significantly diminished hepatic collagen deposition and serum IL-2 level, minimized the elevated nuclear ploidy and cyclic AMP serum level that followed colchicine therapy when administered alone.  (+info)

Research on nucleolar organizer regions of hippocampal neuron in Alzheimer's disease. (4/367)

OBJECTIVE: To understand the cellular genetic expression of the cell's population by studying the nucleolar organizer regions (NORs) of hippocampal neuron of Alzheimer's disease (AD). METHODS: The postmortem human hippocampal tissues were divided into three groups, namely, the young, the elderly and the AD groups. Each group contained tissues from 10 patients. The study was conducted using image pattern analysis of the nucleoli-nucleoplasms ratio of the neurons of Nissl's stained pathological cerebral hippocampal tissues, the area of stain, and the integrating absorption of nucleoli of silver-stained NORs. RESULTS: The nucleoli-nucleoplasms ratio of the neurons of Nissl's stained cerebral hippocampal tissues, the area of stain, and the integrating absorption of the nucleoli of hippocampal neuron were decreased in the elderly and the AD groups as compared with the young group. However, the area of stain and the integrating absorption of the nucleoli of the hippocampal neurons were relatively increased in the AD group in comparison with the elderly group. CONCLUSION: Nissl's stain demonstrates the hypofunction of the hippocampal neurons in the elderly and the AD patients. The Silver stain of NORs shows the decline of rDNA transcription activity of the nucleoli of the hippocampal neurons in the elderly and the AD patients. However, the transcription activity of the nucleoli of the hippocampal neurons of AD patients was relatively improved, and the cellular genetic expression of the cell's population was relatively strengthened. These cellular morphological changes have probably reflected the cellular defensive system.  (+info)

The mitotically phosphorylated form of the transcription termination factor TTF-1 is associated with the repressed rDNA transcription machinery. (5/367)

The transcription termination factor TTF-1 exerts two functions in ribosomal gene (rDNA) transcription: facilitating initiation and mediating termination of transcription. Using HeLa cells, we show that TTF-1 protein is colocalized with the active transcription machinery in the nucleolus and also with the inactive machinery present in certain mitotic nucleolar organizer regions (NORs) when rDNA transcription is repressed. We also show that TTF-1 is specifically phosphorylated during mitosis in a manner dependent on the cdc2-cyclin B kinase pathway and on an okadaic acid-sensitive phosphatase. Interestingly, the mitotically phosphorylated form of TTF-1 appearing at the G(2)/M transition phase was more easily solubilized than was the interphase form. This indicates that the chromatin-binding affinity of TTF-1 appears to be different in mitotic chromosomes compared to the interphase nucleolus. Correlated with this, the other DNA-binding factor, UBF, which interferes with chromatin conformation in the rDNA promoter, was more strongly bound to rDNA during mitosis than at interphase. The reorganization of the mitotic rDNA promoter might be induced by phosphorylation of certain components of the rDNA transcription machinery and participate in silencing of rDNA during mitosis.  (+info)

Chromosomes as well as chromosomal subdomains constitute distinct units in interphase nuclei. (6/367)

Fluorescence in situ hybridization has demonstrated that chromosomes form individual territories in interphase nuclei. However, this technique is not suitable to determine whether territories are mutually exclusive or interwoven. This notion, however, is essential for understanding functional organizations in the cell nucleus. Here, we analyze boundary areas of individual chromosomes during interphase using a sensitive method based on replication labeling and immunocytochemistry. Thymidine analogues IdUrd and CldUrd were incorporated during S-phase into DNA of Chinese Hamster fibroblasts. Cells labeled with IdUrd were fused with cells labeled with CldUrd. Fused nuclei contained both IdUrd or CldUrd labeled chromosomes. Alternatively, the two labels were incorporated sequentially during successive S-phases and segregated to separate chromosomes by culturing the cells one more cell cycle. Metaphase spreads showed IdUrd-, CldUrd- and unlabeled chromosomes. Some chromatids were divided sharply in differently labeled subdomains by sister chromatid exchanges. With both methods, confocal imaging of interphase nuclei revealed labeled chromosomal domains containing fiber-like structures and unlabeled areas. At various sites, fiber-like structures were embedded in other territories. Even so, essentially no overlap between chromosome territories or between subdomains within a chromosome was observed. These observations indicate that chromosome territories and chromosomal subdomains in G(1)-phase are mutually exclusive at the resolution of the light microscope.  (+info)

Molecular dissection of nucleolin's role in growth and cell proliferation: new insights. (7/367)

Cells require optimum protein synthetic activity in order to support cell proliferation, maintain homeostatic and metabolic integrity, and repair damage. Since growth depends on protein synthesis through ribosome biogenesis, the control of biosynthesis of ribosomes is necessarily a key element for control of growth. Nucleolin is a major nucleolar protein of exponentially growing eukaryotic cells, which is directly involved in the regulation of ribosome biogenesis and maturation. The highly conserved nucleolin contains three major domains through which it controls the organization of nucleolar chromatin, packaging of pre-RNA, rDNA transcription, and ribosome assembly. Numerous reports have implicated the involvement of nucleolin either directly or indirectly in the regulation of cell proliferation and growth, cytokinesis, replication, embryogenesis, and nucleogenesis. Nucleolin, an RNA binding protein, is also an autoantigen, a transcriptional repressor, and a switch region targeting factor. In addition, nucleolin exhibits autodegradation, DNA and RNA helicase activities, and DNA-dependent ATPase activity. An interesting aspect of nucleolin action is that it is a target for regulation by proteolysis, methylation, ADP-ribosylation, and phosphorylation by CKII, cdc2, PKC-xi, cyclic AMP-dependent protein kinase, and ecto-protein kinase. For these and other reasons, nucleolin is fundamental to the survival and proliferation of cells. Considerable progress has been made in recent years with the identification of new nucleolin binding proteins that may mediate these many nucleolin-dependent functions. Nucleolin also functions as a cell surface receptor, where it acts as a shuttling protein between cytoplasm and nucleus, and thus can even provide a mechanism for extracellular regulation of nuclear events. Exploration of the regulation of this multifaceted protein in a remarkable number of diverse functions is challenging.  (+info)

Human Nopp140, which interacts with RNA polymerase I: implications for rRNA gene transcription and nucleolar structural organization. (8/367)

Nopp140 is thought to shuttle between nucleolus and cytoplasm. However, the predominant nucleolar localization of Nopp140 homologues from different species suggests that Nopp140 is also involved in events occurring within the nucleolus. In this study, we demonstrated that the largest subunit of RNA polymerase I, RPA194, was coimmunoprecipitated with the human Nopp140 (hNopp140). Such an interaction is mediated through amino acids 204 to 382 of hNopp140. By double immunofluorescence, hNopp140 was colocalized with RNA polymerase I at the rDNA (rRNA genes) transcription active foci in the nucleolus. These results suggest that Nopp140 can interact with RNA polymerase I in vivo. Transfected cells expressing the amino-terminal half of hNopp140, hNopp140N382 (amino acids 1 to 382), displayed altered nucleoli with crescent-shaped structures. This phenotype is reminiscent of the segregated nucleoli induced by actinomycin D treatment, which is known to inhibit rRNA synthesis. Consistently, the hNopp140N382 protein mislocalized the endogenous RNA polymerase I and shut off cellular rRNA gene transcription as revealed by an in situ run-on assay. These dominant negative effects of the mutant hNopp140N382 suggest that Nopp140 plays an essential role in rDNA transcription. Interestingly, ectopic expression of hNopp140 to a very high level caused the formation of a transcriptionally inactive spherical structure occupying the entire nucleolar area which trapped the RNA polymerase I, fibrillarin, and hNopp140 but excluded the nucleolin. The mislocalizations of these nucleolar proteins after hNopp140 overexpression imply that Nopp140 may also play roles in maintenance of nucleolar integrity.  (+info)

The Nucleolus Organizer Region (NOR) is a specific region within the chromosomes, primarily in the short arm of the acrocentric chromosomes (chromosomes 13, 14, 15, 21, and 22). It consists of clusters of repetitive DNA sequences that encode ribosomal RNA (rRNA) genes. During interphase, these regions form the nucleolus, a distinct structure within the nucleus where rRNA transcription, processing, and ribosome assembly occur. The number of NORs in an individual can vary, which has implications in certain genetic conditions and aging processes.

The nucleolus is a structure found within the nucleus of eukaryotic cells (cells that contain a true nucleus). It plays a central role in the production and assembly of ribosomes, which are complex molecular machines responsible for protein synthesis. The nucleolus is not a distinct organelle with a membrane surrounding it, but rather a condensed region within the nucleus where ribosomal biogenesis takes place.

The process of ribosome formation begins in the nucleolus with the transcription of ribosomal DNA (rDNA) genes into long precursor RNA molecules called rRNAs (ribosomal RNAs). Within the nucleolus, these rRNA molecules are cleaved, modified, and assembled together with ribosomal proteins to form small and large ribosomal subunits. Once formed, these subunits are transported through the nuclear pores to the cytoplasm, where they come together to form functional ribosomes that can engage in protein synthesis.

In addition to its role in ribosome biogenesis, the nucleolus has been implicated in other cellular processes such as stress response, cell cycle regulation, and aging. Changes in nucleolar structure and function have been associated with various diseases, including cancer and neurodegenerative disorders.

"Silver staining" is a histological term that refers to a technique used to selectively stain various components of biological tissues, making them more visible under a microscope. This technique is often used in the study of histopathology and cytology. The most common type of silver staining is known as "silver impregnation," which is used to demonstrate the presence of argyrophilic structures, such as nerve fibers and neurofibrillary tangles, in tissues.

The process of silver staining involves the use of silver salts, which are reduced by a developer to form metallic silver that deposits on the tissue components. The intensity of the stain depends on the degree of reduction of the silver ions, and it can be modified by adjusting the concentration of the silver salt, the development time, and other factors.

Silver staining is widely used in diagnostic pathology to highlight various structures such as nerve fibers, axons, collagen, basement membranes, and microorganisms like fungi and bacteria. It has also been used in research to study the distribution and organization of these structures in tissues. However, it's important to note that silver staining is not specific for any particular substance, so additional tests are often needed to confirm the identity of the stained structures.

Ribosomal RNA (rRNA) is a type of RNA molecule that is a key component of ribosomes, which are the cellular structures where protein synthesis occurs in cells. In ribosomes, rRNA plays a crucial role in the process of translation, where genetic information from messenger RNA (mRNA) is translated into proteins.

Ribosomal RNA is synthesized in the nucleus and then transported to the cytoplasm, where it assembles with ribosomal proteins to form ribosomes. Within the ribosome, rRNA provides a structural framework for the assembly of the ribosome and also plays an active role in catalyzing the formation of peptide bonds between amino acids during protein synthesis.

There are several different types of rRNA molecules, including 5S, 5.8S, 18S, and 28S rRNA, which vary in size and function. These rRNA molecules are highly conserved across different species, indicating their essential role in protein synthesis and cellular function.

Ribosomal DNA (rDNA) refers to the specific regions of DNA in a cell that contain the genes for ribosomal RNA (rRNA). Ribosomes are complex structures composed of proteins and rRNA, which play a crucial role in protein synthesis by translating messenger RNA (mRNA) into proteins.

In humans, there are four types of rRNA molecules: 18S, 5.8S, 28S, and 5S. These rRNAs are encoded by multiple copies of rDNA genes that are organized in clusters on specific chromosomes. In humans, the majority of rDNA genes are located on the short arms of acrocentric chromosomes 13, 14, 15, 21, and 22.

Each cluster of rDNA genes contains both transcribed and non-transcribed spacer regions. The transcribed regions contain the genes for the four types of rRNA, while the non-transcribed spacers contain regulatory elements that control the transcription of the rRNA genes.

The number of rDNA copies varies between species and even within individuals of the same species. The copy number can also change during development and in response to environmental factors. Variations in rDNA copy number have been associated with various diseases, including cancer and neurological disorders.

Chromosomes are thread-like structures that exist in the nucleus of cells, carrying genetic information in the form of genes. They are composed of DNA and proteins, and are typically present in pairs in the nucleus, with one set inherited from each parent. In humans, there are 23 pairs of chromosomes for a total of 46 chromosomes. Chromosomes come in different shapes and forms, including sex chromosomes (X and Y) that determine the biological sex of an individual. Changes or abnormalities in the number or structure of chromosomes can lead to genetic disorders and diseases.

Embryonic organizers are specialized cells or tissues in developing embryos that provide critical signals to guide the organization and development of surrounding cells and tissues. They play a crucial role in establishing the body plan and patterning of the organism during embryogenesis. A well-known example is the Spemann-Mangold organizer, first described in amphibians, which induces the formation of the neural tissue and organizes the surrounding tissues to form the body axis. Embryonic organizers have been identified in various animal models, including mammals, birds, and fish, and they are essential for normal embryonic development.

Karyotyping is a medical laboratory test used to study the chromosomes in a cell. It involves obtaining a sample of cells from a patient, usually from blood or bone marrow, and then staining the chromosomes so they can be easily seen under a microscope. The chromosomes are then arranged in pairs based on their size, shape, and other features to create a karyotype. This visual representation allows for the identification and analysis of any chromosomal abnormalities, such as extra or missing chromosomes, or structural changes like translocations or inversions. These abnormalities can provide important information about genetic disorders, diseases, and developmental problems.

Metaphase is a phase in the cell division process (mitosis or meiosis) where the chromosomes align in the middle of the cell, also known as the metaphase plate or equatorial plane. During this stage, each chromosome consists of two sister chromatids attached to each other by a protein complex called the centromere. The spindle fibers from opposite poles of the cell attach to the centromeres of each chromosome, and through a process called congression, they align the chromosomes in the middle of the cell. This alignment allows for accurate segregation of genetic material during the subsequent anaphase stage.

I'm sorry for any confusion, but "Silver" is not a medical term. It is a chemical element with the symbol Ag and atomic number 47. Silver is a soft, white, lustrous transition metal that occurs in its pure, free form (native silver) as an alloy with gold and other metals, and in minerals such as argentite and chlorargyrite.

In the medical field, silver compounds have been used for their antimicrobial properties. For example, silver sulfadiazine is a common topical cream used to prevent or treat wound infections. Colloidal silver, a suspension of silver particles in a liquid, has also been promoted as a dietary supplement and alternative treatment for various conditions, but its effectiveness and safety are not well-established.

Goosecoid protein is not a term that has a specific medical definition. However, it is a biological term related to the field of developmental biology and genetics.

Goosecoid protein is a transcription factor that plays a crucial role in embryonic development, particularly during gastrulation - an early stage of embryogenesis where the three germ layers (ectoderm, mesoderm, and endoderm) are formed. The goosecoid gene encodes this protein, and it is primarily expressed in the Spemann-Mangold organizer, a structure located in the dorsal blastopore lip of amphibian embryos. This organizer region is essential for establishing the body axis and inducing the formation of the central nervous system.

In humans, goosecoid protein homologs have been identified, and they are involved in various developmental processes, including limb development and craniofacial morphogenesis. Dysregulation of goosecoid protein expression or function has been implicated in several congenital disorders and cancer types. However, a direct medical definition focusing on 'Goosecoid Protein' is not available due to its broader biological context.

Silver nitrate is defined as an inorganic compound with the chemical formula AgNO3. It is a white or colorless crystalline solid that is highly soluble in water. Silver nitrate is commonly used in medicine as a topical antiseptic and caustic, particularly for the treatment of wounds, ulcers, and warts. When applied to skin or mucous membranes, it can help to destroy bacteria, viruses, and fungi, and promote healing. However, it can also cause irritation and tissue damage if used inappropriately, so it should be used with caution and under the guidance of a healthcare professional.

Nucleolus organizer regions (NORs) are chromosomal regions crucial for the formation of the nucleolus. In humans, the NORs are ... Baicharoen S, Hirai Y, Srikulnath K, Kongprom U, Hirai H (2016). "Hypervariability of Nucleolus Organizer Regions in Bengal ... Sowmya GV, Nahar P, Astekar M, Agarwal H, Singh MP (2017). "Analysis of silver binding nucleolar organizer regions in ... Bloom SE, Goodpasture C (October 1976). "An improved technique for selective silver staining of nucleolar organizer regions in ...
These rDNA regions are also called nucleolus organizer regions, as they give rise to the nucleolus. In rDNA, the tandem repeats ... In the human genome there are 5 chromosomes with nucleolus organizer regions: the acrocentric chromosomes 13 (RNR1), 14 (RNR2 ... In the nucleus, the rDNA region of the chromosome is visualized as a nucleolus which forms expanded chromosomal loops with rDNA ... Coding regions of rDNA are highly conserved among species but ITS regions are variable due to insertions, deletions, and point ...
... a novel protein of the fibrillar centres of the nucleolus and nucleolus organizer region of mitotic chromosomes". Chromosoma. ... Molecular identity of nucleolus organizer region autoantigen NOR-90 and ribosomal RNA transcription upstream binding factor". J ... to the D17S183 Locus on Chromosome 17q21 and Construction of a Long-Range Restriction Map of the Region". Genomics. 30 (3): 602 ... region of human ribosomal transcription factor UBF". DNA Seq. 12 (4): 267-72. doi:10.3109/10425170109025001. PMID 11916260. ...
... a novel protein of the fibrillar centres of the nucleolus and nucleolus organizer region of mitotic chromosomes". Chromosoma. ...
B") differs from both M. mystacinus and M. brandtii in the pattern of active nucleolus organizer regions on the chromosomes. M ... including DNA sequences and the location of the nucleolus organizer regions. Two studies used microsatellite markers on ... In the Genevan region, the species is also listed as "Critically Endangered" as of 2015. In Hungary, where the species is ... Italy M. alcathoe has been recorded in beech forest in Majella National Park in the region of Abruzzo. Additional specimens of ...
В., Zagorodniuk I. V., Belianin A. N., Liapunova E. A. Nucleolus organizer regions and B-chromosomes of field mice (Mammalia, ... annual gathering of theriologists taking place in different regions of Ukraine since 1993. Scientific interests: fauna and ...
In addition to some protein coding genes, human acrocentric p-arms also contain Nucleolus organizer regions (NORs), from which ... This constricted region of chromosome connects the sister chromatids, creating a short arm (p) and a long arm (q) on the ... Consistently, chromosomal regions that are less densely packed are also more prone to chromosomal translocations in cancers. ... CENP-C has been shown to localise almost exclusively to these regions of CENP-A associated chromatin. In human cells, the ...
Although usually only one or two nucleoli can be seen, a diploid human cell has ten nucleolus organizer regions (NORs) and ... Nucleoli are made of proteins, DNA and RNA, and form around specific chromosomal regions called nucleolar organizing regions. ... Wikimedia Commons has media related to Cell nucleolus. Look up nucleolus in Wiktionary, the free dictionary. Nucleolus under ... It is now known that long noncoding RNAs originating from intergenic regions of the nucleolus are responsible for this ...
Immunohistochemical detection of cell division markers such as Ki-67 or the argyrophilic nucleolus organizer region (AgNOR) ... and mucous membranes are more prone to metastasis than those of other regions. In contrast, mastocytomas of the conjunctiva are ...
During this period, she demonstrated the presence of the nucleolus organizer region on a region on maize chromosome 6, which is ... She produced the first genetic map for maize, linking regions of the chromosome to physical traits. She demonstrated the role ... "The relation of a particular chromosomal element to the development of the nucleoli in Zea mays", Zeitschrift für Zellforschung ... of the telomere and centromere, regions of the chromosome that are important in the conservation of genetic information. She ...
... arranged as tandem repeats in nucleolus organizer regions. Each copy contains a ~13.3 kb sequence encoding the 18S, the 5.8S, ... In higher eukaryotes, TTF-I binds and bends the termination site at the 3' end of the transcribed region. This will force Pol I ... TTF-I, with the help of transcript-release factor PTRF and a T-rich region, will induce Pol I into terminating transcription ... Grummt, Ingrid (15 July 2003). "Life on a planet of its own: regulation of RNA polymerase I transcription in the nucleolus". ...
... nucleolus organizer region MeSH A11.284.430.106.279.345.190.160.830 - synaptonemal complex MeSH A11.284.430.106.279.345.190.160 ... cell nucleolus MeSH A11.284.430.106.279.345.190 - chromosomes MeSH A11.284.430.106.279.345.190.160 - chromosome structures MeSH ...
... an enzyme Nucleolus organizer region, a chromosomal region around which the nucleolus forms in cell biology Norfolk Orbital ...
... locus control region MeSH G14.340.024.630 - nucleolus organizer region MeSH G14.340.024.686 - operon MeSH G14.340.024.686.545 ... locus control region MeSH G14.080.689.650 - operator regions (genetics) MeSH G14.080.689.675 - promoter regions (genetics) MeSH ... flanking region MeSH G14.340.024.340.137.295 - 5' flanking region MeSH G14.340.024.340.137.430 - immunoglobulin switch region ... flanking region MeSH G14.340.024.220.282 - 5' flanking region MeSH G14.340.024.220.400 - introns MeSH G14.340.024.220.760 - ...
... by distinct differences in the number and location of nucleolus organizer regions. The pygmy slow loris is nocturnal, although ... 2007). "Mitochondrial control region and population genetic patterns of Nycticebus bengalensis and N. pygmaeus". International ... Within the whole Indochinese region, populations of the pygmy slow loris have drastically decreased as a result of military ... This demand has recently increased due to human population growth and improved economic conditions within the region. According ...
Nucleolus organizer regions are chromosomal regions crucial for the formation of the nucleolus, located on the short arms of ...
Nucleolus organizer regions are chromosomal regions crucial for the formation of the nucleolus, located on the short arms of ... Sylvester JE, Petersen R, Schmickel RD (1990). "Human ribosomal DNA: novel sequence organization in a 4.5-kb region upstream ... 1985). "Molecular analysis of the heterogeneity region of the human ribosomal spacer". J. Mol. Biol. 183 (2): 213-223. doi: ... nucleotide sequence of the transcription initiation region and comparison of three mammalian genes". Proc. Natl. Acad. Sci. U.S ...
Nucleolus organizer regions are chromosomal regions crucial for the formation of the nucleolus, located on the short arms of ... Sylvester JE, Petersen R, Schmickel RD (1990). "Human ribosomal DNA: novel sequence organization in a 4.5-kb region upstream ... 1985). "Molecular analysis of the heterogeneity region of the human ribosomal spacer". J. Mol. Biol. 183 (2): 213-223. doi: ... nucleotide sequence of the transcription initiation region and comparison of three mammalian genes". Proc. Natl. Acad. Sci. U.S ...
The genes coding for 18S, 28S and 5.8S rRNA are located in the nucleolus organizer region and are transcribed into large ... In the nucleolus, rRNA is synthesized by RNA polymerase I using the specialty genes (rDNA) that encode for it, which are found ... The pre-5S rRNA enters the nucleolus for processing and assembly with 28S and 5.8S rRNA to form the LSU. 18S rRNA forms the ... When the concentration of ANG becomes too high, some studies have found that ANG can bind to the promoter region of rDNA and ...
Nucleolus organizer regions are chromosomal regions crucial for the formation of the nucleolus, located on the short arms of ... Sylvester JE, Petersen R, Schmickel RD (1990). "Human ribosomal DNA: novel sequence organization in a 4.5-kb region upstream ... 1985). "Molecular analysis of the heterogeneity region of the human ribosomal spacer". J. Mol. Biol. 183 (2): 213-223. doi: ... nucleotide sequence of the transcription initiation region and comparison of three mammalian genes". Proc. Natl. Acad. Sci. U.S ...
Nucleolus organizer regions are chromosomal regions crucial for the formation of the nucleolus, located on the short arms of ... Sylvester JE, Petersen R, Schmickel RD (1990). "Human ribosomal DNA: novel sequence organization in a 4.5-kb region upstream ... 1985). "Molecular analysis of the heterogeneity region of the human ribosomal spacer". J. Mol. Biol. 183 (2): 213-223. doi: ... nucleotide sequence of the transcription initiation region and comparison of three mammalian genes". Proc. Natl. Acad. Sci. U.S ...
"Human acrocentric chromosomes with transcriptionally silent nucleolar organizer regions associate with nucleoli", The EMBO ... There are at least 4 SAT chromosomes in each diploid nucleus, and the constriction corresponds to a nucleolar organizer (NOR), ... SAT-chromosomes whose secondary constriction is associated with the formation of the nucleolus are referred to as nucleolar SAT ... a region containing multiple copies of the 18S and 28S ribosomal genes that synthesize ribosomal RNA required by ribosomes. The ...
These regions are called nucleolar organizer regions (NOR). The main roles of the nucleolus are to synthesize rRNA and assemble ... The structural cohesion of the nucleolus depends on its activity, as ribosomal assembly in the nucleolus results in the ... the nucleolus can be seen to consist of three distinguishable regions: the innermost fibrillar centers (FCs), surrounded by the ... The nucleolus is the largest of the discrete densely stained, membraneless structures known as nuclear bodies found in the ...
Northern analysis Northern blot NPD Nu body Nuclear transfer Nuclease Nucleic acid Nucleoid Nucleolar organizer Nucleolus ... Chromosomal deletion Chromosome Chromosome aglet Chromosome banding Chromosome painting Chromosome region p Chromosome region q ... Uptake signal sequence Uracil Uridine V-J joining Val Variable region Variance Variate Variegation Vector Viability Virion ... plasmid Hybrid zone Hybridoma Hydrogen bond Hydroxyapatite Hypermorph Hyperploid Hypervariable locus Hypervariable region ...
The nucleolus is a specialized region within the nucleus where ribosome subunits are assembled. In prokaryotes, DNA processing ... Centrosome: the cytoskeleton organizer: The centrosome produces the microtubules of a cell-a key component of the cytoskeleton ... The nuclear region in the cytoplasm is called the nucleoid. Most prokaryotes are the smallest of all organisms ranging from 0.5 ... Inside the cell is the cytoplasmic region that contains the genome (DNA), ribosomes and various sorts of inclusions. The ...
Closely related species or even populations may differ in their nucleolus organizing regions (NORs), which are genomic regions ... Britton-Davidian, J (2012). "Chromosomal dynamics of nucleolar organizer regions (NORs) in the house mouse: micro-evolutionary ... clustered) Relative sizes of slowly and rapidly evolving regions (within that repeating unit) Noncoding regions evolve very ... example some hybrids or backcrosses between species with different nucleolar organizing regions/ribosomal DNA repeat regions ...
"Other Regions". International Academic Competitions. 10 August 2017. Archived from the original on 2021-10-27. Retrieved 2022- ... including state championship organizers in 2020-21, as well as for the NAQT HSNCT and PACE NSC high school nationals ... which are formed in the nucleolus. ANSWER: ribosomes [10] Some proteins can become infectious agents. This is the name of those ...
"Nucleolus organizers in the wild silkworm Bombyx mandarina and the domesticated silkworm B. mori". Chromosoma. 96 (4): 263-269 ... The USDA allows shipments to areas and regions within the natural range of the butterfly. Some states have their own ... Event organizers sometimes purchase butterflies from breeders to be released during events such as funerals, hospice activities ... and the far eastern regions of Russia. The domesticated silkworm derives from Chinese rather than Japanese or Korean stock. ...
Proteins regions identified as 'stickers' usually consist of Intrinsically Disordered Regions (IDRs) that act as "sticky" ... C. P. Brangwynne, T. J. Mitchison, and A. A. Hyman, "Active liquid-like behavior of nucleoli determines their size and shape in ... Banani SF, Lee HO, Hyman AA, Rosen MK (May 2017). "Biomolecular condensates: organizers of cellular biochemistry". Nature ... Because condensates of the same composition can interact and fuse with each other, if they are tethered to specific regions of ...
1988). "Nucleolus organizers in the wild silkworm Bombyx mandarina and the domesticated silkworm B. mori". Chromosoma. 96 (4): ... and the far eastern regions of Russia. The domestic silk moth derives from Chinese rather than Japanese or Korean stock. Silk ...
Nucleolus organizer regions (NORs) are chromosomal regions crucial for the formation of the nucleolus. In humans, the NORs are ... Baicharoen S, Hirai Y, Srikulnath K, Kongprom U, Hirai H (2016). "Hypervariability of Nucleolus Organizer Regions in Bengal ... Sowmya GV, Nahar P, Astekar M, Agarwal H, Singh MP (2017). "Analysis of silver binding nucleolar organizer regions in ... Bloom SE, Goodpasture C (October 1976). "An improved technique for selective silver staining of nucleolar organizer regions in ...
Silver-binding nucleolus organizer regions in N-methyl-N-nitro-N-nitrosoguanidine-induced gastrointestinal tumors and adjacent ...
Polymorphic nature of nucleolus organizer regions on fishes. Cytogenetic and Cell Genetics, 31: 137-144.; Mantovani et al., ... Polymorphic nature of nucleolus organizer regions on fishes. Cytogenetic and Cell Genetics, 31: 137-144.). In addition to ... Polymorphic nature of nucleolus organizer regions on fishes. Cytogenetic and Cell Genetics, 31: 137-144. ... Karyotype and nucleolus organizer regions of Ophisternon aenigmaticum (Teleostei: Synbranchiformes: Synbranchidae) from ...
Chromosome number and nucleolus organizer regions of the irregular sea urchin Peronella japonica. Chromo-some Information ... The echinoid fauna from Japan and adjacent regions. Part I. Palaeontol Soc Japan Spec Pap No11. Google Scholar ... The echinoid fauna from Japan and adjacent regions. Part II. Palaeontol Soc Japan Spec Pap No13. Google Scholar ... The region containing the non-nucleate egg fragments was transferred to 35-mm dishes and then washed several times with ...
Karyotypes and chromosomal distribution of constitutive heterochromatin and nucleolus organizer regions in three kyphosid fish ... Nuclear DNA content determination in Characiformes fish (Teleostei, Ostariophysi) from the Neotropical region. Genetics and ...
Here, a human autoantibody reactive with the nucleolus organizer regions (NOR) was used to select cDNA clones encoding the ... We determined the genomic structures and complete sequences of the coding regions of the chicken CENP-C and ZW10 genes. These ... The protein was found at the nucleolus and the cytoplasm in interphase and transiently associates with centromeres in mitosis ... Molecular análisis of the 5` region of human ribosomal transcription factor UBF. DNA sequence 12, 267-272, 2001. S. Dühr, A. ...
Duarte OMP, Martins CCC, Waldschmidt AM, Costa MA: Occurrence of multiple nucleolus organizer regions and intraspecific ... which are generally observed in nucleolus organizer regions (NORs), may be related to distinct gene regulation in these ... regions and heterochromatin and between CMA3+ regions and 18S rDNA sites [Brito et al., 2005; Duarte et al., 2009]. However, ... regions or rDNA but rather by duplications of regions due to slippage or uneven crossing-over. ...
Howell WM and Black DA (1980) Controlled silver staining of nucleolus organizer region with protective colloidal developer: A 1 ... Analysis of nucleolar organizer regions has also indicated chromosomal differences between A. fasciatus from northeastern ... Nucleolar organizer regions were detected by silver nitrate staining (Ag NOR) (Howell and Black, 1980). The best metaphases ... Active NOR sites were located at the terminal region of the long arms of a large pair of ST chromosomes in all samples (Figure ...
Silver nitrate impregnation located the nucleolus organizer regions (Ag-NORs) on the short (p) arm of pair 16, however, an ... Nucleolar organizer regions, 18S and 5S rDNA clusters in the chromosomes of Piabina argentea (Characiformes: Characidae). ... The coding region of Agp1 ranged from 5948 bp to 7666 bp and contained 9 exons and 8 introns. The full-length cDNA sequence of ... An analysis of the probability of establishment of C . patzcuarensis in continental Europe revealed that specific regions in ...
... the position of the nucleolus organizer region, and the genome sizes of female and male individuals were determined. The ... the number and positions of nucleolus organizer regions, and the patterns of telomeric DNA sequences were determined for most ... Most ageDMRs were in genomic regions with medium methylation levels and large methylation variation. Orthologous regions in ... Our results are in line with the hypothesis that sperm ageDMRs are in regions under epigenomic evolution and may be part of an ...
... possibly due to the presence of the un-assembled nucleolus organizer NOR-B2 region within the Yr78 candidate gene region. The ... 5. Structural features of two major nucleolar organizer regions (NORs), Nor-B1 and Nor-B2, and chromosome-specific rRNA gene ... which indicates that the Yr78 candidate gene region is much larger than in the current CS RefSeq.v1.1. The comparative analysis ... produced a higher resolution map of Yr78 and mapped it within a 0.05-cM interval that corresponds to an 11.16 Mb region between ...
... recombinant Ngp-1 protein revealed that the antigen was exclusively localized to the nucleolus and nucleolar organizer regions ... recombinant Ngp-1 protein revealed that the antigen was exclusively localized to the nucleolus and nucleolar organizer regions ... recombinant Ngp-1 protein revealed that the antigen was exclusively localized to the nucleolus and nucleolar organizer regions ... recombinant Ngp-1 protein revealed that the antigen was exclusively localized to the nucleolus and nucleolar organizer regions ...
... or nucleolus organizer regions (NORs). The human genome contains five NORs per haploid chromosome set, or 10 NORs per diploid ... 8.5.4.5 Nucleolus. The largest and most prominent "nuclear organelle" is the nucleolus, a highly coiled structure associated ... In less active cells, the nucleolus is much smaller -- as small as 0.5 micron in a mature lymphocyte.1141 Nucleoli are ... Most human nuclei contain only one nucleolus, except for liver cell nuclei which may contain more than one nucleolus935 and ...
nucleolus organizer region GO:0005731 * no_name GO:0070604 * DNA replication factor C core complex ...
Nucleolus organizer regions. 1SS[3599]. Ae. speltoides[3599].. Pm2. Mlu;Mlx[3599]. Reaction to Erysiphe graminis DC.. 5D,5DS. ...
nucleolus organizer region GO:0005731 * brahma complex GO:0035060 * Rpd3L complex GO:0033698 ...
nucleolar organizer region associated proteins 80% * Nucleolus Organizer Region 77% * nucleolus organizer region 66% ... Characterization of nucleolar organizer regions in cells of transmissible venereal tumor in canine: Histochemical study. ... Characterization of the vicuña (Vicugna vicugna) fibre production in the Cusco Region, Perú. ...
nucleolar organizer region associated proteins 80% * Nucleolus Organizer Region 77% * nucleolus organizer region 66% ... Characterization of nucleolar organizer regions in cells of transmissible venereal tumor in canine: Histochemical study. ... Characterization of the vicuña (Vicugna vicugna) fibre production in the Cusco Region, Perú. ... Causes of maternal death in the Callao region, Perú. Descriptive study, 2000-2015. ...
Translocation of the nucleolus organizer region to the human X chromosome.. Am J Hum Genet. 1986 Aug;39(2):245-52. ... An interstitial nucleolus organizer region in the long arm of human chromosome 7: cytogenetic characterization and familial ... Nucleolus organizer regions (NORs) inserted in 6q15.. Hum Genet. 1989 Feb;81(3):289-90. ... Familial insertion of nucleolar organizer regions and cenromere material into the long arm of chromosome 11. Am J Hum Genet. ...
Although the karyotypes are seemingly dominated by metacentrics, substantial variation in nucleolus organizing regions (NORs) ... Nucleolus organizer regions or NORs are significant markers for chromosome identification. Among the species considered ... Wajahatullah MK, Vahidy AA (1990) Karyotyping and localization of nucleolar organizer regions in garlic, Allium sativum L. ... Schubert I, Wobus U (1985) In situ hybridization confirms jumping nucleolus organizing regions in Allium. Chromosoma 92: 143- ...
Camper, J.D.; Hanks, B. Variation in the nucleolus organizer region among new world snakes. J. Herpetol. 1995, 29, 468-471. [ ... The common genomic regions are depicted in yellow. Clat = C. latirostris, Cyac = C. yacare, Mnig = M. niger, Ppal = P. ... The common genomic regions are depicted in yellow. Clat = C. latirostris, Cyac = C. yacare, Mnig = M. niger, Ppal = P. ... For Authors For Reviewers For Editors For Librarians For Publishers For Societies For Conference Organizers ...
Nuclear organizer. A nucleolar organizer is a chromosomal region around which the nucleolus forms. ... This region is known as telomere.. 93. Malpighian tubule. The Malpighian tubule system is a type of excretory and ... The nucleoid is an irregularly shaped region within the cell of a prokaryote that contains all or most of the genetic material ... At each end of a chromosome there is a region of repetitive nucleotide sequences which protects the end of the chromosome from ...
In the diploid, there were 1 or 2 nucleoli in the cells, whereas the induced tetraploids contained 1, 2, 3, or 4. The DNA ... Nucleolus organizer regions (NORs)-stained cells of diploid and induced tetraploid in Korean rose bitterling, Rhodeus uyekii. a ... Next, nucleolus organizer region (NOR) staining was added for 60 min with pipetting. We added 1 drop of 50 % acetic acid (Sigma ... Chromosome metaphase and nucleolus organizer regions (NORs)-stained metaphase of diploid and induced tetraploid in Korean rose ...
Evolutionary pattern of karyotypes, sex chromosomes, nucleolus organizer regions, and meiosis in pholcid spiders (Araneae: ...
Nucleolus is the most prominent nuclear domain (ND) and is where rRNAs (ribosomal RNAs) are synthesized, processed and ... where they coat rDNA repeat or nucleolus organizer regions (NOR) containing short arms (p-arm) of chromosomes. Specifically, ... There is growing evidence ascribing an essential role for the nucleolus in cellular aging. Perturbations in nucleolus structure ... Nucleolus is the most prominent nuclear domain (ND) and is where rRNAs (ribosomal RNAs) are synthesized, processed and ...
Howell WM and Black DA (1980). Controlled silver-staining of nucleolus organizer regions with a protective colloidal developer ... Howell WM and Black DA (1980). Controlled silver-staining of nucleolus organizer regions with a protective colloidal developer ... Controlled silver-staining of nucleolus organizer regions with a protective colloidal developer: a 1-step method. Experientia ... C-banding pattern characterization and multiple nucleolus organizer regions in Moenkhausia sanctaefilomenae (Pisces, Characidae ...
Howell, W. M. & Black, D. A. (1980). Controlled silver-staining of nucleolus organizer regions with a protective colloidal ... Howell, W. M. & Black, D. A. (1980). Controlled silver-staining of nucleolus organizer regions with a protective colloidal ... The karyotype and distribution of constitutive heterochromatin and nucleolus organizer regions (NORs) of Anatolian leuciscine ... fish on the basis of the nucleolar organizing region. Caryologia, 37(4), 401-406. DOI: 10.1080/00087114.1984.10797718 ...
Howell, W. M., & Black, D. A. (1980). Controlled Silver-staining of Nucleolus Organizer Regions with a Protective Colloidal ... Britton-Davidian, J., Cazaux, B., & Catalan, J. (2012). Chromosomal Dynamics of nuclear Organizer Regions (NORs) in the House ...
This may include increasing in the frequency of sister chromatid exchanges and Ag-positive nucleolus organizer regions, ... Furthermore, the study posits that Prostamax may potentially increase the frequency of Ag-positive nucleolus organizer regions ... genes repressed as a result of the age-specific condensation of cellular euchromatin regions, referred to as ... suggesting a selective action on certain chromosomal regions. However, the exact mechanisms through which Prostamax exerts ...
Ag-staining for nucleolus organizer regions (AgNOR) was identified on the telomeric end of the long arm in 7 autosomal ... The chromosome 22q11.2 region has long been implicated in genomic diseases. Some genomic regions exhibit numerous low copy ... In this study we found more regions in chromosomes with staining than presented in the literature for the Bos indicus group ( ... Additionally, deletions of the 7qter region are associated with a range of phenotypes. RESULTS: We report the first case of de ...
  • Nucleolus organizer regions (NORs) are chromosomal regions crucial for the formation of the nucleolus. (wikipedia.org)
  • NORs can also be seen in nucleoli using silver stain, and that is being used to investigate cancerous changes. (wikipedia.org)
  • The distal flanking junction (DJ) of the NORs has been shown to associate with the periphery of nucleoli. (wikipedia.org)
  • 1141 The number of nucleoli in a eukaryotic cell nucleus normally is determined by the number of chromosomes with secondary constrictions, or nucleolus organizer regions (NORs). (nanomedicine.com)
  • However, instead of 10 separate nucleoli, the typical human nucleus contains a single large nucleolus representing the fusion of loops of chromatin from the 10 separate chromosomes with NORs ( Fig. 8.48 ). (nanomedicine.com)
  • Although the karyotypes are seemingly dominated by metacentrics, substantial variation in nucleolus organizing regions ( NORs ) is noteworthy. (pensoft.net)
  • The karyotype and distribution of constitutive heterochromatin and nucleolus organizer regions (NORs) of Anatolian leuciscine endemic to Lake Beysehir, Squalius anatolicus (Bogutskaya, 1997) were analyzed respectively using conventional Giemsa-staining, C-banding and Ag-impregnation. (egejfas.org)
  • Furthermore, the study posits that Prostamax may potentially increase the frequency of Ag-positive nucleolus organizer regions (NORs). (corepeptides.com)
  • Activity satellite association and polymorphism of Ag stained nucleolus organizer regions (Ag+ NORs) in lymphocytes from women with cervical uterine cancer. (org.ua)
  • Nucleoli, prominent nuclear subdomains and sites of ribosome biogenesis, form around nucleolar organizer regions (NORs) that contain rDNA arrays located on human acrocentric chromosome p-arms. (diagenode.com)
  • Actively transcribed rDNA repeats are positioned within the interior of the nucleolus, whereas sequences proximal and distal to NORs are packaged as heterochromatin located at the nucleolar periphery. (diagenode.com)
  • There are also DNA sequences related to rDNA that are on other chromosomes and may be involved in nucleoli formation. (wikipedia.org)
  • rDNA operons in Escherichia coli have been found to cluster near each other, similar to a eukaryotic nucleolus. (wikipedia.org)
  • In general, Melipona species have 2n = 18 chromosomes, and the species of each subgenus share the same characteristics in relation to heterochromatin regions, DAPI/CMA 3 fluorophores, and the number and distribution of 18S rDNA sites. (karger.com)
  • Perturbations in nucleolus structure and rDNA expression have been associated with aging related diseases such as progeria. (grantome.com)
  • Recent studies indicated that nucleolus-localized noncoding RNAs (ncRNAs) contribute to cellular aging by controlling rDNA expression under conditions that influence aging (such as quiescence). (grantome.com)
  • We have now generated preliminary data showing the existence of a novel class of nucleolus-localized ncRNA, SNULs (Single NUcleolus-Localized RNAs) that control rDNA expression. (grantome.com)
  • within the nucleolus, where they coat rDNA repeat or nucleolus organizer regions (NOR) containing short arms (p-arm) of chromosomes. (grantome.com)
  • The nucleolus organizer regions have likewise posed tantalising problems about their massive amplification of rDNA sequences, and how they are regulated and expressed. (aber.ac.uk)
  • Reorganization renders rDNA accessible to repair factors normally excluded from nucleoli. (diagenode.com)
  • We have previously shown that these and other examples of nucleolar dominance in wheat are associated with undermethylation of cytosine residues in certain regions of the dominant rDNA. (ncsu.edu)
  • In addition, we have mapped several DNase I-hypersensitive sites in the intergenic spacer region of the rDNA repeating unit. (ncsu.edu)
  • These regions code for 5.8S, 18S, and 28S ribosomal RNA. (wikipedia.org)
  • Nucleolus is the most prominent nuclear domain (ND) and is where rRNAs (ribosomal RNAs) are synthesized, processed and assembled with ribosomal proteins. (grantome.com)
  • This may include increasing in the frequency of sister chromatid exchanges and Ag-positive nucleolus organizer regions, indicating enhanced chromosomal exchange activities and changes in ribosomal RNA gene activity as well as reducing the frequency of large segments of C-pericentromeric heterochromatin, suggesting a decondensation action on the chromatin. (corepeptides.com)
  • Cytosine methylation in ribosomal DNA and nucleolus organiser expression in wheat. (ncsu.edu)
  • Ribosomal RNA genes at different nucleolar organizer (NOR) loci in hexaploid wheat are expressed at different levels. (ncsu.edu)
  • Оf the research work was to establish the frequency and spectrum of chromosomal aberrations, associations of acrocentric chromosomes in infants from different ecological regions of Ivano-Frankivsk region. (org.ua)
  • Relationship to the active nucleolar organizers. (org.ua)
  • Cytosine methylation has been studied in wheat rRNA genes at nucleolar organizers displaying different activities. (ncsu.edu)
  • The DNA from the remaining diploid chromosomes is distributed in specific regions throughout the nucleoplasm ( Fig. 8.47 ). (nanomedicine.com)
  • Los estudios sobre contenido de ADN nuclear en el género Genypterus son escasos, y el presente trabajo entrega por primera vez la estimación del contenido de ADN nuclear de Genypterus chilensis con un valor 2C = 1,0 + 0,06 pg, valor cercano al descrito para otras especies de Ophidiidae que varían entre 1,2 y 1,68 pg. (scielo.cl)
  • The largest and most prominent "nuclear organelle" is the nucleolus, a highly coiled structure associated with numerous particles but not surrounded by a membrane. (nanomedicine.com)
  • In cells characterized by a high rate of protein synthesis and hence by the need for many ribosomes, the nucleolus can occupy 20-25% of nuclear volume (3-5 micron diameter in a 20-micron cell), mostly comprised of the granular component. (nanomedicine.com)
  • 1141 Nucleoli are frequently located at or near the nuclear envelope, adhering directly to the nuclear lamina or attaching to it by a pedicle. (nanomedicine.com)
  • In nuclei having a centrally located nucleolus, the nuclear envelope is folded to form a nucleolar canal that is in direct contact with the nucleolus. (nanomedicine.com)
  • Nuclear DNA content in 20 species of Siluriformes (Teleostei: Ostariophysi) from the Neotropical region. (geneticsmr.com)
  • Later, Dang et al (3) produced a higher resolution map of Yr78 and mapped it within a 0.05-cM interval that corresponds to an 11.16 Mb region between loci TraesCS6B02G116200 and TraesCS6B02G118000 in the "Chinese Spring" genome (RefSeq v1.1), which contains 15 genes. (ucdavis.edu)
  • The degree of expression of a particular organizer depends on the genetic background, especially on the presence of other NOR loci. (ncsu.edu)
  • Translocation of the nucleolus organizer region to the human X chromosome. (cs-tl.de)
  • An interstitial nucleolus organizer region in the long arm of human chromosome 7: cytogenetic characterization and familial segregation. (cs-tl.de)
  • ZOO-FISH and R-banding reveal extensive conservation of human chromosome regions in euchromatic regions of river buffalo chromosomes. (cnr.it)
  • Our studies define 1p13.3 as a genomic region harboring 16 NDD candidate genes and underscore the critical roles of small CNVs in in silico comparative genomic mapping for disease gene discovery. (bvsalud.org)
  • A cell undergoing mitosis thus has no nucleolus and synthesizes no rRNA. (nanomedicine.com)
  • Some of these sites are located near the initiation region for the 45 S rRNA precursor, while others are associated with a series of short direct repeats 5′ to the 45 S rRNA initiation site. (ncsu.edu)
  • During mitosis, the chromosomes condense into a more compact form and the nucleolus shrinks, then disappears altogether. (nanomedicine.com)
  • Observations of Drosophila salivary glands revealed that genomic regions could switch between states of euchromatin and heterochromatin (facultative heterochromatin), whereas others remain continuously condensed (constitutive heterochromatin). (biologists.com)
  • these enlarge, eventually fusing into the single large nucleolus characteristic of the interphase human nucleus. (nanomedicine.com)
  • Immunohistochemical analysis of tissue sections with affinity-purified antiserum raised against a recombinant Ngp-1 protein revealed that the antigen was exclusively localized to the nucleolus and nucleolar organizer regions in all cell types analyzed. (elsevierpure.com)
  • Most human nuclei contain only one nucleolus, except for liver cell nuclei which may contain more than one nucleolus 935 and cultured HeLa (cancer) cells which may have up to six. (nanomedicine.com)
  • Bex1 shows cell density-dependent accumulation as a condensate either in nucleoli at a low cell density or at the apical cell surface at a high cell density. (biomedcentral.com)
  • The exact sequence of these regions is not included in the human reference genome as of 2016 or the GRCh38.p10 released January 6, 2017. (wikipedia.org)
  • For many regions of the genome, we have detected multiple overlapping transcripts including both small, gene-sized RNAs and large transcripts covering entire gene clusters. (ncsu.edu)
  • Specific regions that are mapped within a GENOME. (childrensmercy.org)
  • The strongest contributors to genome-wide variation in ROH abundance were likely positive selection and increased power to detect ROH in regions with low recombination. (genestogenomes.org)
  • The nucleolus is composed of DNA, RNA, and proteins. (nanomedicine.com)
  • These molecules attach to integral membrane proteins, or penetrate the peripheral regions of the lipid bilayer. (eduhyme.com)
  • In less active cells, the nucleolus is much smaller -- as small as 0.5 micron in a mature lymphocyte. (nanomedicine.com)
  • In the present work, morphometric and cytogenetic analyses were carried out in populations of the fish Astyanax fasciatus (Characidae) from Contas and Recôncavo Sul River basins (State of Bahia, Brazil), providing new data on the genetic structure of this species along the region. (scielo.br)
  • These results show that A. fasciatus populations from northeastern river basins are well differentiated and present peculiar cytogenetic features when compared to populations from other regions. (scielo.br)
  • Low recombination rates were observed in this segment, possibly due to the presence of the un-assembled nucleolus organizer NOR-B2 region within the Yr78 candidate gene region. (ucdavis.edu)
  • The size of the nucleolus correlates with its level of activity. (nanomedicine.com)
  • There is growing evidence ascribing an essential role for the nucleolus in cellular aging. (grantome.com)
  • Characterization of eight species of Anostomidae (Cypriniformes) fish on the basis of the nucleolar organizing region. (egejfas.org)