Tetrahymena thermophila: A species of ciliate protozoa used in genetic and cytological research.Chromosome Breakage: A type of chromosomal aberration involving DNA BREAKS. Chromosome breakage can result in CHROMOSOMAL TRANSLOCATION; CHROMOSOME INVERSION; or SEQUENCE DELETION.Chromosomal Instability: An increased tendency to acquire CHROMOSOME ABERRATIONS when various processes involved in chromosome replication, repair, or segregation are dysfunctional.Chromosomes: 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)Chromosome Mapping: Any method used for determining the location of and relative distances between genes on a chromosome.Chromosome Aberrations: Abnormal number or structure of chromosomes. Chromosome aberrations may result in CHROMOSOME DISORDERS.Chromosome Fragility: Susceptibility of chromosomes to breakage leading to translocation; CHROMOSOME INVERSION; SEQUENCE DELETION; or other CHROMOSOME BREAKAGE related aberrations.Chromosome Banding: Staining of bands, or chromosome segments, allowing the precise identification of individual chromosomes or parts of chromosomes. Applications include the determination of chromosome rearrangements in malformation syndromes and cancer, the chemistry of chromosome segments, chromosome changes during evolution, and, in conjunction with cell hybridization studies, chromosome mapping.Aneuploidy: The chromosomal constitution of cells which deviate from the normal by the addition or subtraction of CHROMOSOMES, chromosome pairs, or chromosome fragments. In a normally diploid cell (DIPLOIDY) the loss of a chromosome pair is termed nullisomy (symbol: 2N-2), the loss of a single chromosome is MONOSOMY (symbol: 2N-1), the addition of a chromosome pair is tetrasomy (symbol: 2N+2), the addition of a single chromosome is TRISOMY (symbol: 2N+1).Chromosomes, Human: Very long DNA molecules and associated proteins, HISTONES, and non-histone chromosomal proteins (CHROMOSOMAL PROTEINS, NON-HISTONE). Normally 46 chromosomes, including two sex chromosomes are found in the nucleus of human cells. They carry the hereditary information of the individual.Chromosome Segregation: The orderly segregation of CHROMOSOMES during MEIOSIS or MITOSIS.Chromosome Fragile Sites: Specific loci that show up during KARYOTYPING as a gap (an uncondensed stretch in closer views) on a CHROMATID arm after culturing cells under specific conditions. These sites are associated with an increase in CHROMOSOME FRAGILITY. They are classified as common or rare, and by the specific culture conditions under which they develop. Fragile site loci are named by the letters "FRA" followed by a designation for the specific chromosome, and a letter which refers to which fragile site of that chromosome (e.g. FRAXA refers to fragile site A on the X chromosome. It is a rare, folic acid-sensitive fragile site associated with FRAGILE X SYNDROME.)X Chromosome: The female sex chromosome, being the differential sex chromosome carried by half the male gametes and all female gametes in human and other male-heterogametic species.Chromosome Disorders: Clinical conditions caused by an abnormal chromosome constitution in which there is extra or missing chromosome material (either a whole chromosome or a chromosome segment). (from Thompson et al., Genetics in Medicine, 5th ed, p429)In Situ Hybridization, Fluorescence: A type of IN SITU HYBRIDIZATION in which target sequences are stained with fluorescent dye so their location and size can be determined using fluorescence microscopy. This staining is sufficiently distinct that the hybridization signal can be seen both in metaphase spreads and in interphase nuclei.Genomic Instability: An increased tendency of the GENOME to acquire MUTATIONS when various processes involved in maintaining and replicating the genome are dysfunctional.Sex Chromosomes: The homologous chromosomes that are dissimilar in the heterogametic sex. There are the X CHROMOSOME, the Y CHROMOSOME, and the W, Z chromosomes (in animals in which the female is the heterogametic sex (the silkworm moth Bombyx mori, for example)). In such cases the W chromosome is the female-determining and the male is ZZ. (From King & Stansfield, A Dictionary of Genetics, 4th ed)Chromosome Deletion: Actual loss of portion of a chromosome.Mitosis: A type of CELL NUCLEUS division by means of which the two daughter nuclei normally receive identical complements of the number of CHROMOSOMES of the somatic cells of the species.Chromosomes, Human, Pair 1: A specific pair of human chromosomes in group A (CHROMOSOMES, HUMAN, 1-3) of the human chromosome classification.Karyotyping: Mapping of the KARYOTYPE of a cell.Telomere: A terminal section of a chromosome which has a specialized structure and which is involved in chromosomal replication and stability. Its length is believed to be a few hundred base pairs.Chromosomes, Fungal: Structures within the nucleus of fungal cells consisting of or containing DNA, which carry genetic information essential to the cell.Chromosomes, Bacterial: Structures within the nucleus of bacterial cells consisting of or containing DNA, which carry genetic information essential to the cell.Chromosomes, Human, Pair 11: A specific pair of GROUP C CHROMOSOMES of the human chromosome classification.Chromosomes, Human, Pair 7: A specific pair of GROUP C CHROMOSOMES of the human chromosome classification.Chromosomes, Human, Pair 17: A specific pair of GROUP E CHROMOSOMES of the human chromosome classification.Chromosomes, Human, Pair 6: A specific pair GROUP C CHROMSOMES of the human chromosome classification.Chromosomes, Human, Pair 9: A specific pair of GROUP C CHROMSOMES of the human chromosome classification.Micronucleus Tests: Induction and quantitative measurement of chromosomal damage leading to the formation of micronuclei (MICRONUCLEI, CHROMOSOME-DEFECTIVE) in cells which have been exposed to genotoxic agents or IONIZING RADIATION.Chromosomes, Human, Pair 21: A specific pair of GROUP G CHROMOSOMES of the human chromosome classification.Chromosomes, Plant: Complex nucleoprotein structures which contain the genomic DNA and are part of the CELL NUCLEUS of PLANTS.Centromere: The clear constricted portion of the chromosome at which the chromatids are joined and by which the chromosome is attached to the spindle during cell division.DNA Damage: Injuries to DNA that introduce deviations from its normal, intact structure and which may, if left unrepaired, result in a MUTATION or a block of DNA REPLICATION. These deviations may be caused by physical or chemical agents and occur by natural or unnatural, introduced circumstances. They include the introduction of illegitimate bases during replication or by deamination or other modification of bases; the loss of a base from the DNA backbone leaving an abasic site; single-strand breaks; double strand breaks; and intrastrand (PYRIMIDINE DIMERS) or interstrand crosslinking. Damage can often be repaired (DNA REPAIR). If the damage is extensive, it can induce APOPTOSIS.Mutation: Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.Sister Chromatid Exchange: An exchange of segments between the sister chromatids of a chromosome, either between the sister chromatids of a meiotic tetrad or between the sister chromatids of a duplicated somatic chromosome. Its frequency is increased by ultraviolet and ionizing radiation and other mutagenic agents and is particularly high in BLOOM SYNDROME.Fanconi Anemia: Congenital disorder affecting all bone marrow elements, resulting in ANEMIA; LEUKOPENIA; and THROMBOPENIA, and associated with cardiac, renal, and limb malformations as well as dermal pigmentary changes. Spontaneous CHROMOSOME BREAKAGE is a feature of this disease along with predisposition to LEUKEMIA. There are at least 7 complementation groups in Fanconi anemia: FANCA, FANCB, FANCC, FANCD1, FANCD2, FANCE, FANCF, FANCG, and FANCL. (from Online Mendelian Inheritance in Man, http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=227650, August 20, 2004)Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Translocation, Genetic: A type of chromosome aberration characterized by CHROMOSOME BREAKAGE and transfer of the broken-off portion to another location, often to a different chromosome.Chromosomes, Human, 6-12 and X: The medium-sized, submetacentric human chromosomes, called group C in the human chromosome classification. This group consists of chromosome pairs 6, 7, 8, 9, 10, 11, and 12 and the X chromosome.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Chromosomes, Human, Pair 16: A specific pair of GROUP E CHROMOSOMES of the human chromosome classification.Recombination, Genetic: Production of new arrangements of DNA by various mechanisms such as assortment and segregation, CROSSING OVER; GENE CONVERSION; GENETIC TRANSFORMATION; GENETIC CONJUGATION; GENETIC TRANSDUCTION; or mixed infection of viruses.Chromosomes, Human, Pair 2: A specific pair of human chromosomes in group A (CHROMOSOMES, HUMAN, 1-3) of the human chromosome classification.Centrosome: The cell center, consisting of a pair of CENTRIOLES surrounded by a cloud of amorphous material called the pericentriolar region. During interphase, the centrosome nucleates microtubule outgrowth. The centrosome duplicates and, during mitosis, separates to form the two poles of the mitotic spindle (MITOTIC SPINDLE APPARATUS).Chromosomes, Human, Pair 22: A specific pair of GROUP G CHROMOSOMES of the human chromosome classification.Chromosomes, Human, Pair 13: A specific pair of GROUP D CHROMOSOMES of the human chromosome classification.Chromosomes, Mammalian: Complex nucleoprotein structures which contain the genomic DNA and are part of the CELL NUCLEUS of MAMMALS.Chromosome Pairing: The alignment of CHROMOSOMES at homologous sequences.Chromosomes, Human, Pair 4: A specific pair of GROUP B CHROMOSOMES of the human chromosome classification.Chromosomes, Human, Pair 8: A specific pair of GROUP C CHROMOSOMES of the human chromosome classification.Chromosomes, Human, Pair 10: A specific pair of GROUP C CHROMOSOMES of the human chromosome classification.Chromosomes, Human, Y: The human male sex chromosome, being the differential sex chromosome carried by half the male gametes and none of the female gametes in humans.Chromosomes, Human, Pair 19: A specific pair of GROUP F CHROMOSOMES of the human chromosome classification.Chromosomes, Artificial, Bacterial: DNA constructs that are composed of, at least, a REPLICATION ORIGIN, for successful replication, propagation to and maintenance as an extra chromosome in bacteria. In addition, they can carry large amounts (about 200 kilobases) of other sequence for a variety of bioengineering purposes.Chromosome Painting: A technique for visualizing CHROMOSOME ABERRATIONS using fluorescently labeled DNA probes which are hybridized to chromosomal DNA. Multiple fluorochromes may be attached to the probes. Upon hybridization, this produces a multicolored, or painted, effect with a unique color at each site of hybridization. This technique may also be used to identify cross-species homology by labeling probes from one species for hybridization with chromosomes from another species.Chromosomes, Human, X: The human female sex chromosome, being the differential sex chromosome carried by half the male gametes and all female gametes in humans.Chromosomes, Human, Pair 5: One of the two pairs of human chromosomes in the group B class (CHROMOSOMES, HUMAN, 4-5).Chromosomes, Human, Pair 12: A specific pair of GROUP C CHROMOSOMES of the human chromosome classification.Chromosomes, Human, 1-3: The large, metacentric human chromosomes, called group A in the human chromosome classification. This group consists of chromosome pairs 1, 2, and 3.Chromosomes, Human, Pair 15: A specific pair of GROUP D CHROMOSOMES of the human chromosome classification.Chromosomes, Human, Pair 14: A specific pair of GROUP D CHROMOSOMES of the human chromosome classification.Chromosomes, Human, Pair 18: A specific pair of GROUP E CHROMOSOMES of the human chromosome classification.Spindle Apparatus: A microtubule structure that forms during CELL DIVISION. It consists of two SPINDLE POLES, and sets of MICROTUBULES that may include the astral microtubules, the polar microtubules, and the kinetochore microtubules.Chromosomes, Artificial, Yeast: Chromosomes in which fragments of exogenous DNA ranging in length up to several hundred kilobase pairs have been cloned into yeast through ligation to vector sequences. These artificial chromosomes are used extensively in molecular biology for the construction of comprehensive genomic libraries of higher organisms.Chromosomes, Human, Pair 20: A specific pair of GROUP F CHROMOSOMES of the human chromosome classification.Joint Instability: Lack of stability of a joint or joint prosthesis. Factors involved are intra-articular disease and integrity of extra-articular structures such as joint capsule, ligaments, and muscles.DNA Repair: The reconstruction of a continuous two-stranded DNA molecule without mismatch from a molecule which contained damaged regions. The major repair mechanisms are excision repair, in which defective regions in one strand are excised and resynthesized using the complementary base pairing information in the intact strand; photoreactivation repair, in which the lethal and mutagenic effects of ultraviolet light are eliminated; and post-replication repair, in which the primary lesions are not repaired, but the gaps in one daughter duplex are filled in by incorporation of portions of the other (undamaged) daughter duplex. Excision repair and post-replication repair are sometimes referred to as "dark repair" because they do not require light.Chromosomes, Human, 16-18: The short, submetacentric human chromosomes, called group E in the human chromosome classification. This group consists of chromosome pairs 16, 17, and 18.Cell Cycle Proteins: Proteins that control the CELL DIVISION CYCLE. This family of proteins includes a wide variety of classes, including CYCLIN-DEPENDENT KINASES, mitogen-activated kinases, CYCLINS, and PHOSPHOPROTEIN PHOSPHATASES as well as their putative substrates such as chromatin-associated proteins, CYTOSKELETAL PROTEINS, and TRANSCRIPTION FACTORS.Genetic Linkage: The co-inheritance of two or more non-allelic GENES due to their being located more or less closely on the same CHROMOSOME.Chromosomes, Human, 13-15: The medium-sized, acrocentric human chromosomes, called group D in the human chromosome classification. This group consists of chromosome pairs 13, 14, and 15.Micronuclei, Chromosome-Defective: Defective nuclei produced during the TELOPHASE of MITOSIS or MEIOSIS by lagging CHROMOSOMES or chromosome fragments derived from spontaneous or experimentally induced chromosomal structural changes.Chromosomes, Human, 21-22 and Y: The short, acrocentric human chromosomes, called group G in the human chromosome classification. This group consists of chromosome pairs 21 and 22 and the Y chromosome.DNA-Binding Proteins: Proteins which bind to DNA. The family includes proteins which bind to both double- and single-stranded DNA and also includes specific DNA binding proteins in serum which can be used as markers for malignant diseases.DNA Replication: The process by which a DNA molecule is duplicated.Chromosome Inversion: An aberration in which a chromosomal segment is deleted and reinserted in the same place but turned 180 degrees from its original orientation, so that the gene sequence for the segment is reversed with respect to that of the rest of the chromosome.Genetic Markers: A phenotypically recognizable genetic trait which can be used to identify a genetic locus, a linkage group, or a recombination event.Kinetochores: Large multiprotein complexes that bind the centromeres of the chromosomes to the microtubules of the mitotic spindle during metaphase in the cell cycle.Ring Chromosomes: Aberrant chromosomes with no ends, i.e., circular.Phenotype: The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.Lymphocytes: White blood cells formed in the body's lymphoid tissue. The nucleus is round or ovoid with coarse, irregularly clumped chromatin while the cytoplasm is typically pale blue with azurophilic (if any) granules. Most lymphocytes can be classified as either T or B (with subpopulations of each), or NATURAL KILLER CELLS.DNA: A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).DNA Sequence, Unstable: A region of DNA that is highly polymorphic and is prone to strand breaks, rearrangements or other MUTATIONS because of the nature of its sequence. These regions often harbor palindromic, or repetitive sequences (REPETITIVE SEQUENCES, NUCLEIC ACID). Variability in stability of the DNA sequence is seen at CHROMOSOME FRAGILE SITES.Chromatids: Either of the two longitudinally adjacent threads formed when a eukaryotic chromosome replicates prior to mitosis. The chromatids are held together at the centromere. Sister chromatids are derived from the same chromosome. (Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)Microsatellite Repeats: A variety of simple repeat sequences that are distributed throughout the GENOME. They are characterized by a short repeat unit of 2-8 basepairs that is repeated up to 100 times. They are also known as short tandem repeats (STRs).Polyploidy: The chromosomal constitution of a cell containing multiples of the normal number of CHROMOSOMES; includes triploidy (symbol: 3N), tetraploidy (symbol: 4N), etc.Chromosome Positioning: The mechanisms of eukaryotic CELLS that place or keep the CHROMOSOMES in a particular SUBNUCLEAR SPACE.Ectromelia: Gross hypo- or aplasia of one or more long bones of one or more limbs. The concept includes amelia, hemimelia, phocomelia, and sirenomelia.Chromosomes, Human, 4-5: The large, submetacentric human chromosomes, called group B in the human chromosome classification. This group consists of chromosome pairs 4 and 5.Saccharomyces cerevisiae: A species of the genus SACCHAROMYCES, family Saccharomycetaceae, order Saccharomycetales, known as "baker's" or "brewer's" yeast. The dried form is used as a dietary supplement.Aphidicolin: An antiviral antibiotic produced by Cephalosporium aphidicola and other fungi. It inhibits the growth of eukaryotic cells and certain animal viruses by selectively inhibiting the cellular replication of DNA polymerase II or the viral-induced DNA polymerases. The drug may be useful for controlling excessive cell proliferation in patients with cancer, psoriasis or other dermatitis with little or no adverse effect upon non-multiplying cells.X-Rays: Penetrating electromagnetic radiation emitted when the inner orbital electrons of an atom are excited and release radiant energy. X-ray wavelengths range from 1 pm to 10 nm. Hard X-rays are the higher energy, shorter wavelength X-rays. Soft x-rays or Grenz rays are less energetic and longer in wavelength. The short wavelength end of the X-ray spectrum overlaps the GAMMA RAYS wavelength range. The distinction between gamma rays and X-rays is based on their radiation source.Genome, Protozoan: The complete genetic complement contained in a set of CHROMOSOMES in a protozoan.Nuclear Proteins: Proteins found in the nucleus of a cell. Do not confuse with NUCLEOPROTEINS which are proteins conjugated with nucleic acids, that are not necessarily present in the nucleus.Loss of Heterozygosity: The loss of one allele at a specific locus, caused by a deletion mutation; or loss of a chromosome from a chromosome pair, resulting in abnormal HEMIZYGOSITY. It is detected when heterozygous markers for a locus appear monomorphic because one of the ALLELES was deleted.X Chromosome Inactivation: A dosage compensation process occurring at an early embryonic stage in mammalian development whereby, at random, one X CHROMOSOME of the pair is repressed in the somatic cells of females.Cloning, Molecular: The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.DNA Transposable Elements: Discrete segments of DNA which can excise and reintegrate to another site in the genome. Most are inactive, i.e., have not been found to exist outside the integrated state. DNA transposable elements include bacterial IS (insertion sequence) elements, Tn elements, the maize controlling elements Ac and Ds, Drosophila P, gypsy, and pogo elements, the human Tigger elements and the Tc and mariner elements which are found throughout the animal kingdom.Meiosis: A type of CELL NUCLEUS division, occurring during maturation of the GERM CELLS. Two successive cell nucleus divisions following a single chromosome duplication (S PHASE) result in daughter cells with half the number of CHROMOSOMES as the parent cells.Telomere Shortening: The loss of some TELOMERE sequence during DNA REPLICATION of the first several base pairs of a linear DNA molecule; or from DNA DAMAGE. Cells have various mechanisms to restore length (TELOMERE HOMEOSTASIS.) Telomere shortening is involved in the progression of CELL AGING.Chromates: Salts of chromic acid containing the CrO(2-)4 radical.Hybrid Cells: Any cell, other than a ZYGOTE, that contains elements (such as NUCLEI and CYTOPLASM) from two or more different cells, usually produced by artificial CELL FUSION.Ataxia Telangiectasia: An autosomal recessive inherited disorder characterized by choreoathetosis beginning in childhood, progressive CEREBELLAR ATAXIA; TELANGIECTASIS of CONJUNCTIVA and SKIN; DYSARTHRIA; B- and T-cell immunodeficiency, and RADIOSENSITIVITY to IONIZING RADIATION. Affected individuals are prone to recurrent sinobronchopulmonary infections, lymphoreticular neoplasms, and other malignancies. Serum ALPHA-FETOPROTEINS are usually elevated. (Menkes, Textbook of Child Neurology, 5th ed, p688) The gene for this disorder (ATM) encodes a cell cycle checkpoint protein kinase and has been mapped to chromosome 11 (11q22-q23).Metaphase: 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.Polymerase Chain Reaction: In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.Chromosomal Proteins, Non-Histone: Nucleoproteins, which in contrast to HISTONES, are acid insoluble. They are involved in chromosomal functions; e.g. they bind selectively to DNA, stimulate transcription resulting in tissue-specific RNA synthesis and undergo specific changes in response to various hormones or phytomitogens.Cell Line: Established cell cultures that have the potential to propagate indefinitely.Mad2 Proteins: Mad2 is a component of the spindle-assembly checkpoint apparatus. It binds to and inhibits the Cdc20 activator subunit of the anaphase-promoting complex, preventing the onset of anaphase until all chromosomes are properly aligned at the metaphase plate. Mad2 is required for proper microtubule capture at KINETOCHORES.Chromosomes, Insect: Structures within the CELL NUCLEUS of insect cells containing DNA.Zea mays: A plant species of the family POACEAE. It is a tall grass grown for its EDIBLE GRAIN, corn, used as food and animal FODDER.DNA Breaks, Double-Stranded: Interruptions in the sugar-phosphate backbone of DNA, across both strands adjacently.Models, Genetic: Theoretical representations that simulate the behavior or activity of genetic processes or phenomena. They include the use of mathematical equations, computers, and other electronic equipment.Protein-Serine-Threonine Kinases: A group of enzymes that catalyzes the phosphorylation of serine or threonine residues in proteins, with ATP or other nucleotides as phosphate donors.Microsatellite Instability: The occurrence of highly polymorphic mono- and dinucleotide MICROSATELLITE REPEATS in somatic cells. It is a form of genome instability associated with defects in DNA MISMATCH REPAIR.Chromosome Structures: Structures which are contained in or part of CHROMOSOMES.Chromosomes, Human, 19-20: The short, metacentric human chromosomes, called group F in the human chromosome classification. This group consists of chromosome pairs 19 and 20.
There is only one region of the mitochondrial chromosome that does not contain a coding sequence and that is the 1 kb region ... Double minute chromosomes (DMs) are also extrachromosomal elements that are associated with genome instability. DMs are ... DMs are thought to be produced through breakages in chromosomes or overreplication of DNA in an organism. Studies show that in ... In plants, eccDNA contains repeated sequences similar to those that are found in the centromeric regions of the chromosomes and ...
"An AT-Rich Sequence in Human Common Fragile Site FRA16D Causes Fork Stalling and Chromosome Breakage in S. cerevisiae". ... Seckel syndrome, a genetic disease characterized by low levels of ATR, results in increased instability of chromosomes at ... Arlt, MF; Glover, TW (Jun 4, 2010). "Inhibition of topoisomerase I prevents chromosome breakage at common fragile sites". DNA ... The instability of CFSs is proposed to stem from late replication: CFSs are likely to initiate proper replication but slow to ...
Chromosome instability syndrome Fenech, M.; Kirsch-Volders, M.; Natarajan, A. T.; Surralles, J.; Crott, J. W.; Parry, J.; ... Fold-back inversions are chimeric sequences that span head-to-head arrangements of inverted tandem-duplicated segments, and are ... Breakage-fusion-bridge (BFB) cycle (also breakage-rejoining-bridge cycle) is a mechanism of chromosomal instability, discovered ... Murnane, John P. (2012). "Telomere dysfunction and chromosome instability". Mutation Research. 730 (1-2): 28-36. doi:10.1016/j. ...
... chromosomal instability MeSH G13.920.590.175.165.180 --- chromosome fragility MeSH G13.920.590.175.175 --- chromosome breakage ... sequence deletion MeSH G13.920.590.762.180 --- chromosome deletion MeSH G13.920.590.762.320 --- gene deletion MeSH G13.920. ... chromosome instability MeSH G13.370.180.180 --- chromosome fragility MeSH G13.380.350 --- gene dosage MeSH G13.380.355 --- ... sequence homology, amino acid MeSH G13.810.550 --- sequence homology, nucleic acid MeSH G13.810.550.830 --- synteny MeSH ...
Without the Dna2, the RPA bound flaps could not be processed which would ultimately lead to cell instability. The Pif1 helicase ... In time, these nicks also cause full chromosome breaks, which could lead to severe mutations and cancers. Other mutations have ... Although cells undergo multiple steps in order to ensure there are no mutations in the genetic sequence, sometimes specific ... While this process seems quite simple and repetitive, defects in Okazaki fragment maturation can cause DNA strand breakage ...
... it is worth noting that the breakage-fusion-bridge cycle involves ring chromosomes too. Particularly, these ring chromosomes ... It is interesting that despite having identical sequences in two halves of the chromosome, the neocentromere is only formed ... Some have attributed this statistic to the possible mitotic instability of ring chromosomes. Centromeres are conventionally ... A chromosome is rearranged to give a ring chromosome, and a linear chromosome. Hence, in hindsight, the first observation of ...
"Microcell mediated chromosome transfer maps the Fanconi anaemia group D gene to chromosome 3p". Nature Genetics. 11 (3): 341-3 ... The members of the Fanconi anemia complementation group do not share sequence similarity; they are related by their assembly ... Futaki M, Liu JM (Dec 2001). "Chromosomal breakage syndromes and the BRCA1 genome surveillance complex". Trends in Molecular ... Fanconi anemia is a genetically homozygous recessive disorder characterized by chromosomal instability, hypersensitivity to DNA ...
Through paired end sequencing, 42 chromosomal rearrangements were found in the long arm of chromosome 4 and a significant ... Rosin MP, German J (1985). "Evidence for chromosome instability in vivo in bloom syndrome: Increased numbers of micronuclei in ... The Micronuclei model is the most accepted model as to how and when the breakage and repair in chromothripsis occurs. In cancer ... Cells with defective chromosome segregation will form micronuclei which contain whole chromosomes or fragments of chromosomes. ...
... can refer to the accumulation of extra copies of DNA or chromosomes, chromosomal translocations, chromosomal ... These mutations can include changes in nucleic acid sequences, chromosomal rearrangements or aneuploidy. Genome instability ... likely attributable to genome instability. Four (ataxia-telangiectasia, ataxia-telangiectasia-like disorder, Nijmegen breakage ... Genome instability (also genetic instability or genomic instability) refers to a high frequency of mutations within the genome ...
... since breakage regions in tumor cells have been plotted around Z-DNA-forming sequences. However, the smaller deletions in ... Champ PC, Maurice S, Vargason JM, Camp T, Ho PS (2004). "Distributions of Z-DNA and nuclear factor I in human chromosome 22: a ... Z-DNA formed via active transcription has been shown to increase genetic instability, creating a propensity towards mutagenesis ... The greatest increase in activity is observed when the Z-DNA sequence is placed three helical turns after the promoter sequence ...
The daughter chromosomes will assemble centromeres in the same place as the parent chromosome, independent of sequence. It has ... Dicentric chromosome) will result in chromosome breakage during mitosis. In some unusual cases human neocentromeres have been ... Overexpression of these centromere genes is thought to increase genomic instability in cancers. Elevated genomic instability on ... "Chromosomes, Chromosome Anomalies". *Gilbert F (1999). "Disease genes and chromosomes: disease maps of the human genome. ...
... meaning that an abundance of rDNA sequences are not prone to generating circular chromosomes from random events like breakage ... Strehler, Bernard L. (1986-01-01). "Genetic instability as the primary cause of human aging". Experimental Gerontology. 21 (4 ... By intra-molecular homologous recombination of the chromosome, eccDNA are formed as well as ERCs. The process for intra- ... Extrachromosomal rDNA circles (aka ERC) are extrachromosomal circular DNA (eccDNA), are self replicating sequences of ribosomal ...
Nijmegen breakage syndrome (NBS) is a rare genetic disorder that has similar chromosomal instability to that seen in people ... bases GAA from the usual 5-33 repetitions of this trinucleotide sequence to greater than 65 repeats on each chromosome. Most ... Iourov, I. Y.; Vorsanova, S. G.; Liehr, T.; Kolotii, A. D.; Yurov, Y. B. (Jul 15, 2009). "Increased chromosome instability ... and low number of lymphocytes in the blood Chromosomal instability (broken pieces of chromosomes) Increased sensitivity of ...
FISH involves the use of fluorescent probes to detect and localize specific DNA sequences on chromosomes, and centromere- ... which are rotations in regions of a chromosome due to chromosomal breakages or intra-chromosomal recombinations. Inversions ... Boukamp, Petra; Popp, Susanne; Krunic, Damir (2005-11-01). "Telomere-Dependent Chromosomal Instability". Journal of ... A dicentric chromosome is an abnormal chromosome with two centromeres. It is formed through the fusion of two chromosome ...
... chromosome instability and fertility defects, but not the developmental defects that are typically found in other NBS patients ... A study found that Nbs1 is the most diverged in DNA sequence in the MRN complex between different primate species and that ... Matsuura S, Kobayashi J, Tauchi H, Komatsu K (2004). "Nijmegen breakage syndrome and DNA double strand break repair by NBS1 ... It is a rare inherited autosomal recessive condition of chrosomal instability. It has been linked to mutations within exons 6- ...
The members of the Fanconi anemia complementation group do not share sequence similarity; they are related by their assembly ... Fanconi anemia is a genetically heterogeneous recessive disorder characterized by cytogenetic instability, hypersensitivity to ... maps to chromosome 6p". Am. J. Hum. Genet. 64 (5): 1400-5. doi:10.1086/302385. PMC 1377877 . PMID 10205272. Medhurst AL, Huber ... DNA crosslinking agents, increased chromosomal breakage, and defective DNA repair. ...
... while loss and gain of whole chromosomes is often due to errors during mitosis. Chromosomes consist of the DNA sequence, and ... Oostra AB, Nieuwint AW, Joenje H, de Winter JP (1 January 2012). "Diagnosis of fanconi anemia: chromosomal breakage analysis". ... As chromosome instability refers to the rate that chromosomes or large portions of chromosomes are changed, there should be ... The genes that control chromosome instability are known as chromosome instability genes and they control pathways such as ...
The members of the Fanconi anemia complementation group do not share sequence similarity; they are related by their assembly ... Fanconi anemia is a genetically heterogeneous recessive disorder characterized by cytogenetic instability, hypersensitivity to ... "FANCB is essential in the male germline and regulates H3K9 methylation on the sex chromosomes during meiosis". Hum. Mol. Genet ... DNA crosslinking agents, increased chromosomal breakage, and defective DNA repair. ...
... is located on chromosome 8 in yeast cells and codes for 723 amino acids producing a protein that weighs 81,581 Da. During ... Keil, R. L.; McWilliams, A. D. (November 1993). "A gene with specific and global effects on recombination of sequences from ... Inactivation of RRM3 causes chromosomal breakage at these Rrm3p associated sites throughout the genome. Rrm3p is also commonly ... "Local chromatin structure at the ribosomal DNA causes replication fork pausing and genome instability in the absence of the S. ...
The genus is also known for its polyploidy, with some species having up to 12 sets of chromosomes. All species of Xenopus have ... The data is searchable via sequence, gene symbol and various synonyms (as used in different publications). Xenbase maps the MOs ... Nbs1 Nijmegen breakage syndrome, RecQL4 Rothmund-Thomson syndrome, c-Myc oncogene and FANC proteins (Fanconi anemia). Xenopus ... have also yielded critical insights into the mechanism of action of human disease genes associated with genetic instability and ...
A telomere is a region of repetitive sequences at each end of eukaryotic chromosomes in most eukaryotes. Telomeres protect the ... eliminating the process of death by chromosome instability or loss, absence of apoptosis-induction pathways, and continued ... Fanconi anemia and Nijmegen breakage syndrome are associated with short telomeres. However, the genes that have mutated in ... TERT proteins from many eukaryotes have been sequenced. By using TERC, TERT can add a six-nucleotide repeating sequence, 5'- ...
Riddoch syndrome Right middle lobe syndrome Riley-Day Syndrome Riley-Day syndrome Ring chromosome 14 syndrome Ring chromosome ... Gräsbeck syndrome Immersion foot syndromes Immune reconstitution inflammatory syndrome Immunodeficiency-centromeric instability ... Nezelof syndrome Nice Guy syndrome Nicolaides-Baraitser syndrome Nicolau-Balus syndrome Night eating syndrome Nijmegen breakage ... syndrome Postural orthostatic tachycardia syndrome Potocki-Lupski syndrome Potocki-Shaffer syndrome Potter sequence Prader- ...
Genomic instability can occur when the replication fork is disturbed or stalled in its migration. This can occur with ... Gene amplification is the increase in copy number of a region of a chromosome. which occur frequently in solid tumors, and can ... Rapid sequencing technologies can identify genetic markers for treatment sensitivity and potential resistance. Certain markers ... and subsequent cycles of bridge-breakage-fusion formations result in large intrachromosomal repeats. The over amplification of ...
These short repetitive sequences of DNA become unstable, leading to a state of microsatellite instability (MSI). Mutated ... VHL results from a mutation in the von Hippel-Lindau tumor suppressor gene on chromosome 3p25.3. Xeroderma pigmentosum (XP) is ... Chrzanowska KH, Gregorek H, Dembowska-Bagińska B, Kalina MA, Digweed M (2012). "Nijmegen breakage syndrome (NBS)". Orphanet J ... Drescher KM, Sharma P, Lynch HT (2010). "Current hypotheses on how microsatellite instability leads to enhanced survival of ...
... and thus can be correctly repaired using the complementary undamaged sequence in a homologous chromosome if it is available for ... Gonzalo S, Kreienkamp R (2016). "Methods to Monitor DNA Repair Defects and Genomic Instability in the Context of a Disrupted ... These include ataxia telangiectasia, Nijmegen breakage syndrome, some subgroups of xeroderma pigmentosum, trichothiodystrophy, ... In contrast to DNA damage, a mutation is a change in the base sequence of the DNA. A mutation cannot be recognized by enzymes ...
... is a term referred to the special characteristic of having two different kinds of nuclei in a cell. This feature is observed in protozoan ciliates and some foraminifera. Ciliates contain two nucleus types: a macronucleus that is primarily used to control metabolism, and a micronucleus which performs reproductive functions and generates the macronucleus. Nuclear dimorphism is subject to complex epigenetic controls. The micronucleus is globally repressed during the vegetative state, and serves as the diploid germline nucleus, whereas all known vegetative gene expression happens in the macronucleus, which is a polyploid somatic nucleus. The ciliated protozoan Tetrahymena is a useful research model for studying nuclear dimorphism; it maintains two distinct nuclear genomes, the micronucleus and the macronucleus. The micronucleus genome contains five chromosomes that undergo mitosis during micronuclear division and meiosis during conjugation, which is the sexual division of ...
So, for a boiler that produces 210 kW (or 700,000 BTU/h) output for each 300 kW (or 1,000,000 BTU/h) heat-equivalent input, its thermal efficiency is 210/300 = 0.70, or 70%. This means that the 30% of the energy is lost to the environment. An electric resistance heater has a thermal efficiency of at or very near 100%, so, for example, 1500W of heat are produced for 1500W of electrical input. When comparing heating units, such as a 100% efficient electric resistance heater to an 80% efficient natural gas-fueled furnace, energy prices must be compared to find the lower cost. ...
... is similar in appearance to the mineraloid jet and is sometimes used as a jet imitation. Anthracite differs from ordinary bituminous coal by its greater hardness (2.75-3 on the Mohs scale[9]), its higher relative density of 1.3-1.4, and luster, which is often semi-metallic with a mildly brown reflection. It contains a high percentage of fixed carbon and a low percentage of volatile matter. It is also free from included soft or fibrous notches and does not soil the fingers when rubbed.[3] Anthracitization is the transformation of bituminous coal into anthracite. The moisture content of fresh-mined anthracite generally is less than 15 percent. The heat content of anthracite ranges from 22 to 28 million Btu per short ton (26 to 33 MJ/kg) on a moist, mineral-matter-free basis. The heat content of anthracite coal consumed in the United States averages 25 million Btu/ton (29 MJ/kg), on the as-received basis (i.e., containing both inherent moisture and mineral matter). Since the 1980s, ...
... is the phenomenon by which up to thousands of clustered chromosomal rearrangements occur in a single event in localised and confined genomic regions in one or a few chromosomes, and is known to be involved in both cancer and congenital diseases. It occurs through one massive genomic rearrangement during a single catastrophic event in the cell's history. It is believed that for the cell to be able to withstand such a destructive event, the occurrence of such an event must be the upper limit of what a cell can tolerate and survive. The chromothripsis phenomenon opposes the conventional theory that cancer is the gradual acquisition of genomic rearrangements and somatic mutations over time. The simplest model as to how these rearrangements occur is through the simultaneous fragmentation of distinct chromosomal regions (breakpoints show a non-random distribution) and then subsequent imperfect reassembly by DNA repair pathways or aberrant DNA replication mechanisms. ...
... (also genetic instability or genomic instability) refers to a high frequency of mutations within the genome of a cellular lineage. These mutations can include changes in nucleic acid sequences, chromosomal rearrangements or aneuploidy. Genome instability does occur in bacteria. In multicellular organisms genome instability is central to carcinogenesis, and in humans it is also a factor in some neurodegenerative diseases such as amyotrophic lateral sclerosis or the neuromuscular disease myotonic dystrophy. The sources of genome instability have only recently begun to be elucidated. A high frequency of externally caused DNA damage can be one source of genome instability since DNA damages can cause inaccurate translesion synthesis past the damages or errors in repair, leading to mutation. Another source of genome instability may be epigenetic or mutational reductions in ...
... refers to the structure of sequences for eukaryotic chromosomes. Some fine sequences are included in more than one class, so the classification listed is not intended to be completely separate. Some sequences are required for a properly functioning chromosome: Centromere: Used during cell division as the attachment point for the spindle fibers. Telomere: Used to maintain chromosomal integrity by capping off the ends of the linear chromosomes. This region is a microsatellite, but its function is more specific than a simple tandem repeat. Throughout the eukaryotic kingdom, the overall structure of chromosome ends is conserved and is characterized by the telomeric tract - a series of short G-rich repeats. This is succeeded by an extensive subtelomeric region consisting of various types and lengths of repeats - the telomere ...
Changes in the genome that allow uncontrolled cell proliferation or cell immortality are responsible for cancer. It is believed that the major changes in the genome that lead to cancer arise from mutations in tumor suppressor genes. In 1997, Kinzler and Bert Vogelstein grouped these cancer susceptibility genes into two classes: "caretakers" and "gatekeepers". In 2004, a third classification of tumor suppressor genes was proposed by Franziska Michor, Yoh Iwasa, and Martin Nowak; "landscaper" genes. Caretaker genes encode products that stabilize the genome. Fundamentally, mutations in caretaker genes lead to genomic instability. Tumor cells arise from two distinct classes of genomic instability: mutational instability arising from changes in the nucleotide sequence of DNA and chromosomal instability arising from improper rearrangement of chromosomes. In contrast to caretaker genes, gatekeeper genes encode gene ...
The chromosomes of a cell are in the cell nucleus. They carry the genetic information. Chromosomes are made up of DNA and protein combined as chromatin. Each chromosome contains many genes. Chromosomes come in pairs: one set from the mother; the other set from the father. Cytologists label chromosomes with numbers.[1]. Chromosomes are present in every cell nucleus with very few and special exceptions. This means they are found in all eukaryotes, since only eukaryotes have cell nuclei. When eukaryote cells divide, the chromosomes also divide. When a somatic (body) cell (such as a muscle cell) divides, the process is called mitosis. Before mitosis, the cell copies all the chromosomes and then it can divide. When they duplicate, ...
The chromosomes of a cell are in the cell nucleus. They carry the genetic information. Chromosomes are made up of DNA and protein combined as chromatin. Each chromosome contains many genes. Chromosomes come in pairs: one set from the mother; the other set from the father. Cytologists label chromosomes with numbers.[1] Chromosomes are present in every cell nucleus with very few and special exceptions. This means they are found in all eukaryotes, since only eukaryotes have cell nuclei. When eukaryote cells divide, the chromosomes also divide. When a somatic (body) cell (such as a muscle cell) divides, the process is called mitosis. Before mitosis, the cell copies all the chromosomes and then it can divide. When they duplicate, ...
A microchromosome is a type of very small chromosome which is a typical component of the karyotype of birds, some reptiles, fish, and amphibians; they tend to be absent in mammals. They are less than 20 Mb in size; chromosomes which are greater than 40 Mb in size are known as macrochromosomes, while those between 20 and 40 Mb are classified as intermediate chromosomes. Microchromosomes are characteristically very small and often cytogenetically indistinguishable in a karyotype. While originally thought to be insignificant fragments of chromosomes, in species where they have been studied they have been found to be rich in genes. In chickens, microchromosomes have been estimated to contain between 50 and 75% of all genes. The presence of ...
There are 890 known diseases related to this chromosome.[citation needed] Some of these diseases are hearing loss, Alzheimer's disease, glaucoma and breast cancer. Rearrangements and mutations of chromosome 1 are prevalent in cancer and many other diseases. Patterns of sequence variation reveal signals of recent selection in specific genes that may contribute to human fitness, and also in regions where no function is evident. Complete monosomy (only having one copy of the entire chromosome) is invariably lethal before birth.[14] Complete trisomy (having three copies of the entire chromosome) is lethal within days after conception.[14] Some partial deletions and partial duplications produce birth defects. The following diseases are some of those related to genes on chromosome 1 (which contains the most known genetic diseases of any human ...
... (MEP) is a genetic programming variant encoding multiple solutions in the same chromosome. MEP representation is not specific (multiple representations have been tested). In the simplest variant, MEP chromosomes are linear strings of instructions. This representation was inspired by Three-address code. MEP strength consists in the ability to encode multiple solutions, of a problem, in the same chromosome. In this way one can explore larger zones of the search space. For most of the problems this advantage comes with no running-time penalty compared with genetic programming variants encoding a single solution in a chromosome.[1][2][3]. ...
ލައިޓް މައިކްރަސްކޯޕަކުން ބަލައިފިނަމަ ޕްލޭޓްލިޓްތައް ހުންނާނީ ވަށް ނުވަތަ ކުކުޅު ބިސް ބުރުގެ ބައްޓަމަށެވެ. ޕްލޭޓްލިޓް އުފެދިފައިވަނީ ސާފު ހުދުކުލައިގެ އަރިމަތީ ބަޔަކާއި، ކުލަ އެކުލެވޭ މެދު ބައެއްގެ މަައްޗަށެވެ. މިބުނި ސާފު ހުދުކުލައިގެ އަރިމަތީބަޔަށް ކިޔަނީހައިއަލޯމީރް(އިނގިރޭސި ބަހުން: Hyalomere) އެވެ.ކުލަ އެކުލެވޭ މެދުގައިވާ ބަޔަށް ކިޔަނީ ގްރެނިއޫލޯމީރް(އިނގިރޭސި ބަހުން: Granulomere)ނުވަތަ ކްރޯމަމީރް(އިނގިރޭސި ބަހުން: Chromomere) އެވެ. އިލެކްޓްރޯން މައިކްރޯސްކޯޕަކުން ބަލައިފިނަމަ ޕްލޭޓްލިޓްގެ ބޭރުފަށަލަ(އިނގިރޭސި ބަހުން: Cell membrane)ހުންނަނީ ...
To cause genomic instability particularly at chromosome loci that are intrinsically difficult to replicate because of the ... and repetitive sequences [22]. Human centromeres consist largely of repetitive short sequences (a-satellite DNA sequences) that ... These results suggest that pericentromeric regions are refractory to prompt repair after replication stress-induced breakage in ... and repetitive sequences [22]. Human centromeres consist largely of repetitive short sequences (a-satellite DNA sequences) that ...
This research shows that the region of chromosome 9 that contains the FXN locus is intrinsically prone to breakage in vivo even ... Somatic instability of the ex… *• Inducible and reversible phen… *• Mitochondrial pore opening an… ... Deep sequencing of mitochondr… *• Crystal Structure of Bacillus… *• Downregulation of GSTK1 Is a … ... This chromosome fragility involves the generation of chromosome/chromatid gaps or breaks, or the high frequency loss of one or ...
This may in turn lead to genomic instability [23]. The cancer cells and inflammatory cells in stroma of NPC patients have been ... Matrix association region/scaffold attachment region (MAR/SAR) sequence: its vital role in mediating chromosome breakages in ... To identify the position of the chromosome breaks, the sequencing results were aligned with the AF9 gene sequence accessed from ... Chromosomal breakage occurs during apoptosis and chromosome rearrangement. Chromosomal breakages tend to cluster in certain ...
There is only one region of the mitochondrial chromosome that does not contain a coding sequence and that is the 1 kb region ... Double minute chromosomes (DMs) are also extrachromosomal elements that are associated with genome instability. DMs are ... DMs are thought to be produced through breakages in chromosomes or overreplication of DNA in an organism. Studies show that in ... In plants, eccDNA contains repeated sequences similar to those that are found in the centromeric regions of the chromosomes and ...
Fused chromosomes may break during mitosis, with repeated fusion/breakage cycles resulting in chromosomal instability, ... are protective caps terminating each chromosome that prevent this attrition from reaching coding sequences (22). More ... OSullivan RJ, Karlseder J. Telomeres: protecting chromosomes against genome instability. Nat Rev Mol Cell Biol. 2010;11(3):171 ... Functional analysis of the chromosome 9p21.3 coronary artery disease risk locus. Arterioscler Thromb Vasc Biol. 2009;29(10): ...
... chromosome breakage and fusion, rDNA changes, and loss of repeat sequences. Chromosome sets with extensive homoeology showed ... Chromosome instability (gain and loss) was variable among chromosomes (Table S1). Chromosomes A1, A2, C1, and C2 were each ... Chromosomal Instability and Rearrangement Were Not Randomly Distributed Across the Genome.. Chromosome instability began as ... Chromosomal Breakage, Fusion, and Autosyndetic Chromosome Rearrangement.. Chromosomal breakage and fragment loss were detected ...
Mitotic instability was assessed by the frequency of anaphase bridges. The results suggest that human ring chromosomes can be ... The majority of such rings contain subtelomeric sequences. Constitutional ring chromosomes and most rings in leukaemias belong ... Variation in size and number is extensive, and breakage-fusion-bridge events occur at a high frequency. Abnormalities in ... The second category consists of rings with amplified sequences, primarily from chromosome 12, characteristically occurring in ...
... chromosomes prone to breakage; this instability could be the origin of a gene swap between two chromosomes that has occurred in ... The similar DNA sequences on chromosomes 11 and 22 make them likely to recombine if breakage occurs. ... Detail from image showing chromosome shift. "Der11" is an abnormal chromosomes 11 that includes DNA from chromosomes 22 ( ... Roes lab was part of the international collaboration that sequenced human chromosome 22 and published the result in December. ...
... increased chromosome breakage) and defective DNA repair.. Defects in PALB2 are the cause of pancreatic cancer type 3 (PNCA3) [ ... Synthetic peptide within Human PALB2 aa 1100-1150 conjugated to Keyhole Limpet Haemocyanin (KLH). The exact sequence is ... At the cellular level it is associated with hypersensitivity to DNA-damaging agents, chromosomal instability ( ...
... increased chromosome breakage) and defective DNA repair.. Defects in BRCA2 are a cause of glioma type 3 (GLM3) [MIM:613029]. ... At the cellular level it is associated with hypersensitivity to DNA-damaging agents, chromosomal instability ( ... and a next-generation sequencing platform (NGS-RabMAb®) ...
G-banding visualizes only large-scale genetic instability, including aneuploidy, chromosome breakages, and chromosome ... next-generation sequencing, and transcriptome functional analysis. G-banding revealed random chromosome breakages and ... This result is surprising because DNA instability associated with aneuploidy, polyploidy, or chromosome breakages usually ... The picture illustrates trisomy and near-centromere breakage of chromosomes 1, 3, monosomy of chromosomes 11; absence of 2 ...
Roy K., Kodama S., Suzuki K., Watanabe M. Delayed cell death, giant cell formation and chromosome instability induced by X- ... The results suggest that the observed genomic instability result from these delayed DNA breakage, and activation of p53 ... which implicated the interstitial telomere repeat-like sequences, or recombinational hotspots, in perpetuating chromosomal ... Radiation-induced Genomic Instability in HTHyR1 Clone.. Induction of genomic instability by X-irradiation was examined in HTHyR ...
"An AT-Rich Sequence in Human Common Fragile Site FRA16D Causes Fork Stalling and Chromosome Breakage in S. cerevisiae". ... Seckel syndrome, a genetic disease characterized by low levels of ATR, results in increased instability of chromosomes at ... Arlt, MF; Glover, TW (Jun 4, 2010). "Inhibition of topoisomerase I prevents chromosome breakage at common fragile sites". DNA ... The instability of CFSs is proposed to stem from late replication: CFSs are likely to initiate proper replication but slow to ...
We also develop novel methods using NextGen sequencing to identify chromosome fragile sites in the human genome. ... We are interested in the mechanisms of how replication defects lead to DNA strand breakage, chromosomal rearrangements and ... genome instability, which are the underlying cause of many human diseases including cancer. ...
The increased instability of the resultant chromosome led to the observed inversion between chromosomes 11 and 15, presumably ... Telomeres are composed of repetitive G-rich sequences and proteins that form a dynamic cap to maintain chromosome stability as ... The additional abnormalities, involving chromosomes 11, 12 and 15, which were the source of the chromosome instability and MLL ... chromosome in the 15q14 region (Figure 2(g)). Breakage of these two unstable chromosomes in a single cell would have allowed ...
... stages of cervical neoplasia and DNA damage in 1p36 DNA sequences of chromosome 1 in cervical epithelium using DNA breakage ... 1p36 is a chromosomal site of genomic instability in cervical intraepithelial neoplasia.. aacute;vila H, Fernández JL, Gosálvez ... enables detection and quantification of DNA breakage in the entire genome or within specific DNA sequences in single cells. We ... Evaluation of oxidative DNA damage in pigeon erythrocytes using DNA breakage detection-fluorescence in situ hybridization (DBD- ...
... chromosome breakage followed by NHEJ-mediated circularization or broken-end fusion to another chromosome telomere; and ... CONCLUSIONS/SIGNIFICANCE: HR between repeated sequences resulting in secondary rearrangements was the most prevalent pathway ... as mutations underlying inherited diseases as well as in the karyotypes of many cancers exhibiting ongoing genome instability ... We also observed examples of chromosomes with extensive ongoing end decay in mec1 tlc1 mutants, suggesting that Mec1 protects ...
Amino Acid Sequence Homology Chromosome Breakage Chromosomal Instability 1999 107 Citations (Scopus) ...
Next-generation sequencing enables use of whole-genome sequence typing (WGST) as a viable and discriminatory tool for ... Telomeres are specialised structures that cap the ends of chromosomes. They shorten with each cell division and have been ... Mutational signature analysis also confirms that extreme genomic instability in EAC can be driven by somatic BRCA2 mutations. ... or breakage-fusion-bridge (KRAS, MDM2 and RFC3). Telomere shortening is more prominent in EACs bearing localized complex ...
What is dicentric chromosome? Meaning of dicentric chromosome medical term. What does dicentric chromosome mean? ... Looking for online definition of dicentric chromosome in the Medical Dictionary? dicentric chromosome explanation free. ... leading to the formation of dicentric chromosomes and classical breakage-fusion-bridge (BFB) cycles followed by genome ... A telomere hypothesis of cellular aging has been proposed, where the loss of telomere sequences provides the signal for cells ...
Rice Chromosomes 11 and 12 Sequencing Consortia (2005). The sequence of rice chromosomes 11 and 12, rice in disease resistance ... Therefore, it is not exceptional to find that at least one member of duplicated chromosome pairs have terminal breakages/ ... However, such illegitimate pairing near the termini may increase genomic instability due to multivalent formation and ... Using multiple chromosome sequence alignment (Tang et al., 2008b), we revealed homology between R11 and R12 and their ...
... which can be visualized on a metaphase chromosome spread. These common fragile sites (CFS) are conserved across species and are ... Replication stress induces physical breakage at discrete loci in chromosomes, ... An AT-Rich Sequence in Human Common Fragile Site FRA16D Causes Fork Stalling and Chromosome Breakage in S. cerevisiae. Mol. ... T.W. Glover, M.F.A. & Casper, A. (2005) Mechanisms of common fragile site instability. Hum. Mol. Gen. Spec No. 2, R197-205. H. ...
... after enrichment and sequencing, this allows precise, genome-wide mapping of the breaks. ... An AT-rich sequence in human common fragile site FRA16D causes fork stalling and chromosome breakage in S. cerevisiae. . Mol. ... Genomic instability-an evolving hallmark of cancer. . Nat. Rev. Mol. Cell Biol. 11, 220-228 (2010). ... Genome-wide translocation sequencing reveals mechanisms of chromosome breaks and rearrangements in B cells. . Cell 147, 107-119 ...
... we used chromosomal painting with chromosome 11 sequences as a FISH probe. Chromosome 11 was found in 16% of anaphase bridges, ... or in patients with chromosome breakage syndromes, such as Bloom syndrome (20). Anaphase bridges can be formed as a result of ... Alternatively, lagging anaphase chromosomes, like bridged chromosomes, could also be the result of dicentric chromosomes, if ... but have different short-arm sequences. All three marker chromosomes share portions of chromosomes 4 and 11, but have different ...
... a finding that indicates genome instability and is consistent with increased chromosome breakage. Approximately 20% of cells ... Exome sequencing was performed as described previously for the Dutch kindred (44) and for the US kindred (45). The variants ... Impairments in chromosome maintenance are linked to rare chromosome breakage disorders. Here, we have identified a chromosome ... Destabilized SMC5/6 complex leads to chromosome breakage syndrome with severe lung disease. Saskia N. van der Crabben,1 Marije ...
  • Mitotic instability was assessed by the frequency of anaphase bridges. (nih.gov)
  • During the progression of the cell cycle, these dicentric chromosomes will be competitively pulled towards the opposite poles of the mitotic spindle (each centromere towards one pole), and their stretching will result in the formation of bridges during anaphase (the step that precedes cell division). (thefreedictionary.com)
  • During division, these cells frequently exhibit lagging chromosomes at both metaphase and anaphase, suggesting defects in the mitotic apparatus or kinetochore. (pnas.org)
  • During mitotic division, we observed multiple segregational defects, including multipolar spindles, lagging chromosomes, and anaphase bridges, leading to chromosomal breakage at telophase into centric and acentric micronuclei. (pnas.org)
  • 7-9 This commensal polarises macrophages to produce diffusible clastogens (or chromosome-breaking factors) that break double-stranded DNA, disrupt mitotic spindles and generate CIN through a bystander effect (BSE). (bmj.com)
  • Early in this century Theodore Boveri (1914), after extensive studies of the mitotic appara- tus and chromosomes of both normal and neoplastic cells, proposed that cells of malignant neo- plasms possess the uniform characteristic of abnormal karyotypic morphology. (damasgate.com)
  • this circular chromosome replaces one normal chromosome and presents unique mitotic behavior. (biomedcentral.com)
  • Through each cell cycle, ring chromosomes will experience mitotic disturbance induced by ring chromosome instability and result in three different fates of stable ring transmission, ring size changes by one sister chromatid exchange, or interlocked rings by two sister chromatid exchanges. (biomedcentral.com)
  • The beginning of the mitotic phase is accompanied by chromosome condensation, which is essential for topoisomerase II-dependent DNA decatenation of intertwined sister chromatids. (asm.org)
  • mutant expressing cells expressed sufficient levels of Mad2, BubR1, and cyclin B1 to sustain mitotic arrest, and these cells had normal chromosome ploidy. (stanford.edu)
  • The chromosomal location of ribosomal DNA clusters within the nucleolar organization region (NORs) and telomeric (TTAGGG) n sequences were detected by fluorescent in situ hybridization (FISH). (biomedcentral.com)
  • The 3′ end of the telomeric sequence on the main filament ends with a single-stranded guanine-rich protrusion, which is folded into a loop that inserts itself in between the double helix of DNA, which in turn opens forming a triple helix structure called D-Loop (displacement loop). (hematologyinprogress.net)
  • Telomeric DNA protects chromosome ends through its association with the six-subunit shelterin complex. (cdc.gov)
  • The telomeric repeat insertion occurred either without modification of the sequence at the break site or with processing of the ends produced by the break involving deletions, insertions or target site duplications [ 17 ] (Additional data file 1). (biomedcentral.com)
  • We also observed microsatellite instability (MIN) with most of the tested markers in seven of eight oncocytomas and one of 69 clear cell carcinomas. (elsevier.com)
  • Spontaneous mutations, including loss of heterozygosity, chromosome translocation and DNA deletion, are associated with global hypomethylation in cancer. (biomedcentral.com)
  • The spontaneous frequencies of instability can be increased by treatments as varied as exposure to UV light, culture in the presence of intercalating agents, cold storage, temperature shifts during culture, nutritional shifts, and the regeneration of protoplasts. (asmscience.org)
  • DNA polymerase has been shown to pause at CTG and CGG triplet repeat sequences, which can result in continual expansion via slippage. (wikipedia.org)
  • Common fragile sites are considered part of normal chromosome structure and are present in all (or nearly all) individuals in a population. (wikipedia.org)
  • May be involved in interstrand DNA cross-link repair and in the maintenance of normal chromosome stability. (cancer.gov)
  • Enterococcus faecalis , a human intestinal commensal, can polarise macrophages to produce a bystander effect that causes double-stranded DNA breaks, tetraploidy and chromosomal instability (CIN) in target cells and induces inflammation and CRC in interleukin (IL) 10 knockout mice. (bmj.com)
  • As a result, the kinases ATM and ATR are activated at the unprotected chromosome ends and this DNA damage response (DDR) signalling induces replicative arrest and senescence or apoptosis. (cdc.gov)
  • Using a combination of fluorescence in situ hybridization (FISH) and immunofluorescence combined with FISH (IF-FISH) on metaphase chromosome spreads, we demonstrate that centromere inactivation has evolved on a neo-Y chromosome fusion in the Japan Sea threespine stickleback fish ( Gasterosteus nipponicus ). (springer.com)
  • Korenberg J. R. & Rykowski, M. C. Human genome organization: Alu, lines, and the molecular structure of metaphase chromosome bands. (thefullwiki.org)
  • These results indicate that some of the chromosomal instability observed within these cancer cells might be the result of cytoskeletal defects and breakage-fusion-bridge cycles. (pnas.org)
  • Here, I use a chromosome-based strategy to find potential chromosome regions associated with disease, and show an example of cancer. (usda.gov)
  • This research was supported by a National Science Foundation Graduate Research Fellowship (DGE-1256082), the National Institutes of Health Chromosome Metabolism and Cancer Training Grant (T32 CA009657), a National Institutes of Health grant (R01 GM116853), and the Fred Hutchinson Cancer Research Center. (springer.com)
  • We performed mutation accumulation assays and next generation sequencing on 19 strains, including 16 msh2 missense variants implicated in Lynch cancer syndrome. (g3journal.org)
  • Patients with Bloom's syndrome, a rare chromosome breakage syndrome caused by inactivation of the RecQ helicase BLM, result in phenotypes associated with accelerated aging and develop cancer at a very young age. (proquest.com)
  • An increased number of chromosomes with a specific type of abnormality that prevents cancer cells from repairing their DNA may prove useful in predicting the response to cisplatin in breast cancer. (medpagetoday.com)
  • To explore the chromosomal underpinnings of these clinical responses, Richardson and colleagues tested chemotherapeutic responses in various breast cancer cell lines, following this with genotyping and chromosome copy number analyses. (medpagetoday.com)
  • In this study, 94 unrelated familial prostate cancer cases from the University of Michigan Prostate Cancer Genetics Project (n = 54) and Johns Hopkins University (n = 40) were subjected to targeted next-generation sequencing of the exons, including UTRs, of NBN. (cdc.gov)
  • Sequencing of germline DNA from additional male relatives showed partial co-segregation of the NBN S706X mutation with prostate cancer. (cdc.gov)
  • E. coli RecQ is a close relative of five human proteins, mutations in at least three of which cause genome instability underlying cancer-predisposition syndromes: Bloom, Werner, and Rothmund-Thomson. (bcm.edu)
  • Whole-genome sequence data were obtained for colon adenocarcinoma and rectum adenocarcinoma patients participating in The Cancer Genome Atlas, via the Cancer Genomics Hub, using the GeneTorrent file acquisition tool. (biomedcentral.com)
  • It is likely that there are many different causes of chromosome instability in cancer cells. (duke.edu)
  • In a podcast , Texas Advanced Computing Center Technology Writer and Editor Jorge Salazar explains that DNA naturally folds itself into cross-shaped structures called cruciforms that protrude along the sprawling length of its double helix, noting that there is an abundance of DNA cruciforms, with scientists estimating that as many as 500,000 cruciform-forming sequences may exist on average in a single normal human genome. (sapo.pt)
  • Dr. Vasquez is a professor in the Division of Pharmacology and Toxicology at the UT Austin College of Pharmacy, and has been recognized for pioneering contributions concerning genome instability, particularly by demonstrating that noncanonical DNA structures can be mutagenic, and for discovering new roles for DNA repair factors. (sapo.pt)
  • Nevertheless, work over recent years has established that breaks along the chromosomes do not occur randomly but rather often coincide with the regions containing repetitive elements capable of adopting non-canonical DNA secondary structures. (gatech.edu)
  • I will present our new findings related to three sequence motifs that can adopt different secondary structures. (gatech.edu)
  • These modifications need to be explored, beginning with the primary etiology that causes the inadequate segregation of the sex chromosomes, up to the metabolic disorders that appear in adult life and which tend to diminish the life expectancy of women with TS. (biomedcentral.com)
  • The latest molecular analysis involving worldwide populations of A. huronensis [ 9 ], using mitochondrial cox 1 sequences, indicated that the monophyletic species comprises two slightly differentiated lineages: one is better supported and involves tapeworms from China, the USA and the UK, while the other is represented by worms from continental Europe and South Africa. (biomedcentral.com)
  • The nucleotide sequence which acts as a template for the primer is not replicated. (hematologyinprogress.net)
  • A unifying hypothesis to help explain the findings in the embryonic, fetal, neonatal, and adolescent periods, as well as in adulthood, and the pathogenesis of this disorder, relates to changes in DNA conformation and its assembly without modifying its nucleotide sequence. (biomedcentral.com)
  • By using new cytogenetic tools to identify all of the homoeologous chromosomes, we conducted a cytological investigation of 50 resynthesized Brassica napus allopolyploids across generations S 0:1 to S 5:6 and in the S 10:11 generation. (pnas.org)
  • A cytogenetic analysis of the new local triploid population of the caryophyllidean tapeworm Atractolytocestus huronensis , a unique parthenogenetic species with the ability to colonise new regions, was performed to understand the inner structure of its chromosome complement. (biomedcentral.com)
  • The cytogenetic analysis confirmed the karyotype composed from eight chromosome triplets (3n = 24) as well as the existence of a pair of NORs located on each chromosome of the second triplet. (biomedcentral.com)
  • Fanconi anemia is a genetically heterogeneous recessive disorder characterized by cytogenetic instability hypersensitivity to DNA crosslinking agents increased chromosomal breakage and defective DNA repair. (bio-rad.com)
  • Patients carrying an autosomal ring chromosome shared certain clinical manifestations including proportional growth retardation, developmental delay, mild to severe intellectual disability, microcephaly, and mild to intermediate dysmorphic facial features. (biomedcentral.com)
  • Moreover, the open ends can recombine with other parts of the genome, starting a chain reaction of recombinations and chromosome alterations that can lead to cell death or transformation. (pharmacologicalsciences.us)
  • In collaboration with Sue Jinks-Robertson's lab, we have also characterized chromosome alterations in strains with mutations in Topoisomerase I and cells treated with Topoisomerase I inhibitors. (duke.edu)
  • Note that the 'protein existence' evidence does not give information on the accuracy or correctness of the sequence(s) displayed. (uniprot.org)
  • These mutations cause small changes in the protein sequence of antibodies and lead to increased antibody affinity for specific antigens. (ucdenver.edu)
  • We propose that Sap1 is an architectural chromatin-associated protein, required for chromosome organization. (asm.org)
  • A chromosome is an organized structure of DNA and protein that is found in cells . (thefullwiki.org)
  • Chromosomes of higher organisms ( eukaryotes ) contain DNA and protein. (thefullwiki.org)
  • Protein sequence analysis revealed rs200904105 influences the phosphorylation process (post-translational modification) of DHFR and docking simulation suggested methotrexate to have a higher affinity towards rs121913223 mutant form. (omicsonline.org)
  • Members of this group are related by their assembly into a common nuclear protein complex rather than by sequence similarity. (nih.gov)