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)
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.
The orderly segregation of CHROMOSOMES during MEIOSIS or MITOSIS.
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.
The reciprocal exchange of segments at corresponding positions along pairs of homologous CHROMOSOMES by symmetrical breakage and crosswise rejoining forming cross-over sites (HOLLIDAY JUNCTIONS) that are resolved during CHROMOSOME SEGREGATION. Crossing-over typically occurs during MEIOSIS but it may also occur in the absence of meiosis, for example, with bacterial chromosomes, organelle chromosomes, or somatic cell nuclear chromosomes.
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.
Separase is a caspase-like cysteine protease, which plays a central role in triggering ANAPHASE by cleaving the SCC1/RAD21 subunit of the cohesin complex. Cohesin holds the sister CHROMATIDS together during METAPHASE and its cleavage results in chromosome segregation.
The phase of cell nucleus division following METAPHASE, in which the CHROMATIDS separate and migrate to opposite poles of the spindle.
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.
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.
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.
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.
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)
Securin is involved in the control of the metaphase-anaphase transition during MITOSIS. It promotes the onset of anaphase by blocking SEPARASE function and preventing proteolysis of cohesin and separation of sister CHROMATIDS. Overexpression of securin is associated with NEOPLASTIC CELL TRANSFORMATION and tumor formation.
Abnormal number or structure of chromosomes. Chromosome aberrations may result in CHROMOSOME DISORDERS.
Large multiprotein complexes that bind the centromeres of the chromosomes to the microtubules of the mitotic spindle during metaphase in the cell cycle.
Structures within the nucleus of fungal cells consisting of or containing DNA, which carry genetic information essential to the cell.
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.
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.
Proteins obtained from the species SACCHAROMYCES CEREVISIAE. The function of specific proteins from this organism are the subject of intense scientific interest and have been used to derive basic understanding of the functioning similar proteins in higher eukaryotes.
The alignment of CHROMOSOMES at homologous sequences.
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.
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.
Chemical agents that increase the rate of genetic mutation by interfering with the function of nucleic acids. A clastogen is a specific mutagen that causes breaks in chromosomes.
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.
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.
The process by which a DNA molecule is duplicated.
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.
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.
Tests of chemical substances and physical agents for mutagenic potential. They include microbial, insect, mammalian cell, and whole animal tests.
An autosomal recessive disorder characterized by telangiectatic ERYTHEMA of the face, photosensitivity, DWARFISM and other abnormalities, and a predisposition toward developing cancer. The Bloom syndrome gene (BLM) encodes a RecQ-like DNA helicase.
The first phase of cell nucleus division, in which the CHROMOSOMES become visible, the CELL NUCLEUS starts to lose its identity, the SPINDLE APPARATUS appears, and the CENTRIOLES migrate toward opposite poles.
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.
Proteins found in any species of fungus.
Interruptions in the sugar-phosphate backbone of DNA, across both strands adjacently.
PHENOTHIAZINES with an amino group at the 3-position that are green crystals or powder. They are used as biological stains.
Enzymes catalyzing the transfer of an acetyl group, usually from acetyl coenzyme A, to another compound. EC 2.3.1.
The complex series of phenomena, occurring between the end of one CELL DIVISION and the end of the next, by which cellular material is duplicated and then divided between two daughter cells. The cell cycle includes INTERPHASE, which includes G0 PHASE; G1 PHASE; S PHASE; and G2 PHASE, and CELL DIVISION PHASE.
Phase of the CELL CYCLE following G1 and preceding G2 when the entire DNA content of the nucleus is replicated. It is achieved by bidirectional replication at multiple sites along each chromosome.
Proteins obtained from the species Schizosaccharomyces pombe. The function of specific proteins from this organism are the subject of intense scientific interest and have been used to derive basic understanding of the functioning similar proteins in higher eukaryotes.
A type of chromosomal aberration involving DNA BREAKS. Chromosome breakage can result in CHROMOSOMAL TRANSLOCATION; CHROMOSOME INVERSION; or SEQUENCE DELETION.
A Rec A recombinase found in eukaryotes. Rad51 is involved in DNA REPAIR of double-strand breaks.
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).
A genus of ascomycetous fungi of the family Schizosaccharomycetaceae, order Schizosaccharomycetales.
The failure of homologous CHROMOSOMES or CHROMATIDS to segregate during MITOSIS or MEIOSIS with the result that one daughter cell has both of a pair of parental chromosomes or chromatids and the other has none.
Complexes of enzymes that catalyze the covalent attachment of UBIQUITIN to other proteins by forming a peptide bond between the C-terminal GLYCINE of UBIQUITIN and the alpha-amino groups of LYSINE residues in the protein. The complexes play an important role in mediating the selective-degradation of short-lived and abnormal proteins. The complex of enzymes can be broken down into three components that involve activation of ubiquitin (UBIQUITIN-ACTIVATING ENZYMES), conjugation of ubiquitin to the ligase complex (UBIQUITIN-CONJUGATING ENZYMES), and ligation of ubiquitin to the substrate protein (UBIQUITIN-PROTEIN LIGASES).
DNA TOPOISOMERASES that catalyze ATP-dependent breakage of both strands of DNA, passage of the unbroken strands through the breaks, and rejoining of the broken strands. These enzymes bring about relaxation of the supercoiled DNA and resolution of a knotted circular DNA duplex.
A family of structurally-related DNA helicases that play an essential role in the maintenance of genome integrity. RecQ helicases were originally discovered in E COLI and are highly conserved across both prokaryotic and eukaryotic organisms. Genetic mutations that result in loss of RecQ helicase activity gives rise to disorders that are associated with CANCER predisposition and premature aging.
An E3 ubiquitin ligase primarily involved in regulation of the metaphase-to-anaphase transition during MITOSIS through ubiquitination of specific CELL CYCLE PROTEINS. Enzyme activity is tightly regulated through subunits and cofactors, which modulate activation, inhibition, and substrate specificity. The anaphase-promoting complex, or APC-C, is also involved in tissue differentiation in the PLACENTA, CRYSTALLINE LENS, and SKELETAL MUSCLE, and in regulation of postmitotic NEURONAL PLASTICITY and excitability.
An antineoplastic antibiotic produced by Streptomyces caespitosus. It is one of the bi- or tri-functional ALKYLATING AGENTS causing cross-linking of DNA and inhibition of DNA synthesis.
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.
An increased tendency of the GENOME to acquire MUTATIONS when various processes involved in maintaining and replicating the genome are dysfunctional.
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.
A nucleoside that substitutes for thymidine in DNA and thus acts as an antimetabolite. It causes breaks in chromosomes and has been proposed as an antiviral and antineoplastic agent. It has been given orphan drug status for use in the treatment of primary brain tumors.
CIRCULAR DNA that is interlaced together as links in a chain. It is used as an assay for the activity of DNA TOPOISOMERASES. Catenated DNA is attached loop to loop in contrast to CONCATENATED DNA which is attached end to end.
An increased tendency to acquire CHROMOSOME ABERRATIONS when various processes involved in chromosome replication, repair, or segregation are dysfunctional.
A syndrome characterized by growth retardation, severe MENTAL RETARDATION, short stature, a low-pitched growling cry, brachycephaly, low-set ears, webbed neck, carp mouth, depressed nasal bridge, bushy eyebrows meeting at the midline, hirsutism, and malformations of the hands. The condition may occur sporadically or be associated with an autosomal dominant pattern of inheritance or duplication of the long arm of chromosome 3. (Menkes, Textbook of Child Neurology, 5th ed, p231)
The interval between two successive CELL DIVISIONS during which the CHROMOSOMES are not individually distinguishable. It is composed of the G phases (G1 PHASE; G0 PHASE; G2 PHASE) and S PHASE (when DNA replication occurs).
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.
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.
Macromolecular complexes formed from the association of defined protein subunits.
The period of the CELL CYCLE following DNA synthesis (S PHASE) and preceding M PHASE (cell division phase). The CHROMOSOMES are tetraploid in this point.
A group of methylazirinopyrroloindolediones obtained from certain Streptomyces strains. They are very toxic antibiotics used as ANTINEOPLASTIC AGENTS in some solid tumors. PORFIROMYCIN and MITOMYCIN are the most useful members of the group.
The prophase of the first division of MEIOSIS (in which homologous CHROMOSOME SEGREGATION occurs). It is divided into five stages: leptonema, zygonema, PACHYNEMA, diplonema, and diakinesis.
The three-part structure of ribbon-like proteinaceous material that serves to align and join the paired homologous CHROMOSOMES. It is formed during the ZYGOTENE STAGE of the first meiotic division. It is a prerequisite for CROSSING OVER.
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).
The material of CHROMOSOMES. It is a complex of DNA; HISTONES; and nonhistone proteins (CHROMOSOMAL PROTEINS, NON-HISTONE) found within the nucleus of a cell.
An alkaloid isolated from Colchicum autumnale L. and used as an antineoplastic.
Penetrating, high-energy electromagnetic radiation emitted from atomic nuclei during NUCLEAR DECAY. The range of wavelengths of emitted radiation is between 0.1 - 100 pm which overlaps the shorter, more energetic hard X-RAYS wavelengths. The distinction between gamma rays and X-rays is based on their radiation source.
A subclass of PEPTIDE HYDROLASES that catalyze the internal cleavage of PEPTIDES or PROTEINS.
A DNA-binding protein that consists of 5 polypeptides and plays an essential role in DNA REPLICATION in eukaryotes. It binds DNA PRIMER-template junctions and recruits PROLIFERATING CELL NUCLEAR ANTIGEN and DNA POLYMERASES to the site of DNA synthesis.
The asymmetrical segregation of genes during replication which leads to the production of non-reciprocal recombinant strands and the apparent conversion of one allele into another. Thus, e.g., the meiotic products of an Aa individual may be AAAa or aaaA instead of AAaa, i.e., the A allele has been converted into the a allele or vice versa.
Proteoglycans consisting of proteins linked to one or more CHONDROITIN SULFATE-containing oligosaccharide chains.
A family of highly conserved serine-threonine kinases that are involved in the regulation of MITOSIS. They are involved in many aspects of cell division, including centrosome duplication, SPINDLE APPARATUS formation, chromosome alignment, attachment to the spindle, checkpoint activation, and CYTOKINESIS.
A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.
Gross hypo- or aplasia of one or more long bones of one or more limbs. The concept includes amelia, hemimelia, phocomelia, and sirenomelia.
The first continuously cultured human malignant CELL LINE, derived from the cervical carcinoma of Henrietta Lacks. These cells are used for VIRUS CULTIVATION and antitumor drug screening assays.
Permanent dilation of preexisting blood vessels (CAPILLARIES; ARTERIOLES; VENULES) creating small focal red lesions, most commonly in the skin or mucous membranes. It is characterized by the prominence of skin blood vessels, such as vascular spiders.
Proteins that catalyze the unwinding of duplex DNA during replication by binding cooperatively to single-stranded regions of DNA or to short regions of duplex DNA that are undergoing transient opening. In addition DNA helicases are DNA-dependent ATPases that harness the free energy of ATP hydrolysis to translocate DNA strands.
A cyclin subtype that is transported into the CELL NUCLEUS at the end of the G2 PHASE. It stimulates the G2/M phase transition by activating CDC2 PROTEIN KINASE.
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.
A group of enzymes which catalyze the hydrolysis of ATP. The hydrolysis reaction is usually coupled with another function such as transporting Ca(2+) across a membrane. These enzymes may be dependent on Ca(2+), Mg(2+), anions, H+, or DNA.
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.
A genus of the family Muridae consisting of eleven species. C. migratorius, the grey or Armenian hamster, and C. griseus, the Chinese hamster, are the two species used in biomedical research.
An order of fungi in the phylum Ascomycota that multiply by budding. They include the telomorphic ascomycetous yeasts which are found in a very wide range of habitats.
Structures which are contained in or part of CHROMOSOMES.
A group of enzymes that catalyzes the phosphorylation of serine or threonine residues in proteins, with ATP or other nucleotides as phosphate donors.
Deoxyribonucleic acid that makes up the genetic material of fungi.
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.
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.
Nocodazole is an antineoplastic agent which exerts its effect by depolymerizing microtubules.
Established cell cultures that have the potential to propagate indefinitely.
The phase of cell nucleus division following PROPHASE, when the breakdown of the NUCLEAR ENVELOPE occurs and the MITOTIC SPINDLE APPARATUS enters the nuclear region and attaches to the KINETOCHORES.
A DNA-binding protein that mediates DNA REPAIR of double strand breaks, and HOMOLOGOUS RECOMBINATION.
An aurora kinase that is a component of the chromosomal passenger protein complex and is involved in the regulation of MITOSIS. It mediates proper CHROMOSOME SEGREGATION and contractile ring function during CYTOKINESIS.
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.
Genes that code for proteins that regulate the CELL DIVISION CYCLE. These genes form a regulatory network that culminates in the onset of MITOSIS by activating the p34cdc2 protein (PROTEIN P34CDC2).
Slender, cylindrical filaments found in the cytoskeleton of plant and animal cells. They are composed of the protein TUBULIN and are influenced by TUBULIN MODULATORS.
Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.
Male germ cells derived from SPERMATOGONIA. The euploid primary spermatocytes undergo MEIOSIS and give rise to the haploid secondary spermatocytes which in turn give rise to SPERMATIDS.
An alkylating agent in cancer therapy that may also act as a mutagen by interfering with and causing damage to DNA.
Highly conserved proteins that specifically bind to and activate the anaphase-promoting complex-cyclosome, promoting ubiquitination and proteolysis of cell-cycle-regulatory proteins. Cdc20 is essential for anaphase-promoting complex activity, initiation of anaphase, and cyclin proteolysis during mitosis.
The final phase of cell nucleus division following ANAPHASE, in which two daughter nuclei are formed, the CYTOPLASM completes division, and the CHROMOSOMES lose their distinctness and are transformed into CHROMATIN threads.
A colorless and flammable gas at room temperature and pressure. Ethylene oxide is a bactericidal, fungicidal, and sporicidal disinfectant. It is effective against most micro-organisms, including viruses. It is used as a fumigant for foodstuffs and textiles and as an agent for the gaseous sterilization of heat-labile pharmaceutical and surgical materials. (From Reynolds, Martindale The Extra Pharmacopoeia, 30th ed, p794)
That portion of the electromagnetic spectrum immediately below the visible range and extending into the x-ray frequencies. The longer wavelengths (near-UV or biotic or vital rays) are necessary for the endogenous synthesis of vitamin D and are also called antirachitic rays; the shorter, ionizing wavelengths (far-UV or abiotic or extravital rays) are viricidal, bactericidal, mutagenic, and carcinogenic and are used as disinfectants.
The functional hereditary units of FUNGI.
The chromosomal constitution of cells, in which each type of CHROMOSOME is represented twice. Symbol: 2N or 2X.
A genus, Muntiacus, of the deer family (Cervidae) comprising six species living in China, Tibet, Nepal, India, the Malay Peninsula, and neighboring island countries. They are usually found in forests and areas of dense vegetation, usually not far from water. They emit a deep barklike sound which gives them the name "barking deer." If they sense a predator they will "bark" for an hour or more. They are hunted for their meat and skins; they thrive in captivity and are found in many zoos. The Indian muntjac is believed to have the lowest chromosome number in mammals and cell lines derived from them figure widely in chromosome and DNA studies. (From Walker's Mammals of the World, 5th ed., p1366)

The conserved protein kinase Ipl1 regulates microtubule binding to kinetochores in budding yeast. (1/802)

Chromosome segregation depends on kinetochores, the structures that mediate chromosome attachment to the mitotic spindle. We isolated mutants in IPL1, which encodes a protein kinase, in a screen for budding yeast mutants that have defects in sister chromatid separation and segregation. Cytological tests show that ipl1 mutants can separate sister chromatids but are defective in chromosome segregation. Kinetochores assembled in extracts from ipl1 mutants show altered binding to microtubules. Ipl1p phosphorylates the kinetochore component Ndc10p in vitro and we propose that Ipl1p regulates kinetochore function via Ndc10p phosphorylation. Ipl1p localizes to the mitotic spindle and its levels are regulated during the cell cycle. This pattern of localization and regulation is similar to that of Ipl1p homologs in higher eukaryotes, such as the human aurora2 protein. Because aurora2 has been implicated in oncogenesis, defects in kinetochore function may contribute to genetic instability in human tumors.  (+info)

Rec8p, a meiotic recombination and sister chromatid cohesion phosphoprotein of the Rad21p family conserved from fission yeast to humans. (2/802)

Our work and that of others defined mitosis-specific (Rad21 subfamily) and meiosis-specific (Rec8 subfamily) proteins involved in sister chromatid cohesion in several eukaryotes, including humans. Mutation of the fission yeast Schizosaccharomyces pombe rec8 gene was previously shown to confer a number of meiotic phenotypes, including strong reduction of recombination frequencies in the central region of chromosome III, absence of linear element polymerization, reduced pairing of homologous chromosomes, reduced sister chromatid cohesion, aberrant chromosome segregation, defects in spore formation, and reduced spore viability. Here we extend the description of recombination reduction to the central regions of chromosomes I and II. We show at the protein level that expression of rec8 is meiosis specific and that Rec8p localizes to approximately 100 foci per prophase nucleus. Rec8p was present in an unphosphorylated form early in meiotic prophase but was phosphorylated prior to meiosis I, as demonstrated by analysis of the mei4 mutant blocked before meiosis I. Evidence for the persistence of Rec8p beyond meiosis I was obtained by analysis of the mutant mes1 blocked before meiosis II. A human gene, which we designate hrec8, showed significant primary sequence similarity to rec8 and was mapped to chromosome 14. High mRNA expression of mouse and human rec8 genes was found only in germ line cells, specifically in testes and, interestingly, in spermatids. hrec8 was also expressed at a low level in the thymus. Sequence similarity and testis-specific expression indicate evolutionarily conserved functions of Rec8p in meiosis. Possible roles of Rec8p in the integration of different meiotic events are discussed.  (+info)

Sister chromatid-based DNA repair is mediated by RAD54, not by DMC1 or TID1. (3/802)

In the mitotic cell cycle of the yeast Saccharomyces cerevisiae, the sister chromatid is preferred over the homologous chromosome (non-sister chromatid) as a substrate for DNA double-strand break repair. However, no genes have yet been shown to be preferentially involved in sister chromatid-mediated repair. We developed a novel method to identify genes that are required for repair by the sister chromatid, using a haploid strain that can embark on meiosis. We show that the recombinational repair gene RAD54 is required primarily for sister chromatid-based repair, whereas TID1, a yeast RAD54 homologue, and the meiotic gene DMC1, are dispensable for this type of repair. Our observations suggest that the sister chromatid repair pathway, which involves RAD54, and the homologous chromosome repair pathway, which involves DMC1, can substitute for one another under some circumstances. Deletion of RAD54 in S.cerevisiae results in a phenotype similar to that found in mammalian cells, namely impaired DNA repair and reduced recombination during mitotic growth, with no apparent effect on meiosis. The principal role of RAD54 in sister chromatid-based repair may also be shared by mammalian and yeast cells.  (+info)

Characterization of the components of the putative mammalian sister chromatid cohesion complex. (4/802)

Establishing and maintaining proper sister chromatid cohesion throughout the cell cycle are essential for maintaining genome integrity. To understand how sister chromatid cohesion occurs in mammals, we have cloned and characterized mouse orthologs of proteins known to be involved in sister chromatid cohesion in other organisms. The cDNAs for the mouse orthologs of SMC1S.c. and SMC3S.c. , mSMCB and mSMCD respectively, were cloned, and the corresponding transcripts and proteins were characterized. mSMCB and mSMCD are transcribed at similar levels in adult mouse tissues except in testis, which has an excess of mSMCD transcripts. The mSMCB and mSMCD proteins, as well as the PW29 protein, a mouse homolog of Mcd1pS.c./Rad21S.p., form a complex similar to cohesin in X. laevis. mSMCB, mSMCD and PW29 protein levels show no significant cell-cycle dependence. The bulk of the mSMCB, mSMCD and PW29 proteins undergo redistribution from the chromosome vicinity to the cytoplasm during prometaphase and back to the chromatin in telophase. This pattern of intracellular localization suggests a complex role for this group of SMC proteins in chromosome dynamics. The PW29 protein and PCNA, which have both been implicated in sister chromatid cohesion, do not colocalize, indicating that these proteins may not function in the same cohesion pathway. Overexpression of a PW29-GFP fusion protein in mouse fibroblasts leads to inhibition of proliferation, implicating this protein and its complex with SMC proteins in the control of mitotic cycle progression.  (+info)

Chromosomal analysis of peripheral lymphocytes of patients before and after radiation synovectomy with samarium-153 particulate hydroxyapatite. (5/802)

OBJECTIVE: Radiation synovectomy may be indicated for the treatment of chronic synovitis. A number of factors may affect its current use, including availability, limited evidence for its efficacy compared to intra-articular glucocorticoid, and concerns regarding the potential long-term effects of radiation exposure, particularly in younger patients. Specific chromosome-type abnormalities in peripheral lymphocytes can be useful indicators of whole-body radiation exposure. The frequency of these aberrations has been shown to increase in patients who have had radiation synovectomy using yttrium-90 by up to five times compared to baseline levels. Samarium-153 particulate hydroxyapatite (Sm-153 PHYP) is a new radiopharmaceutical currently on trial which appears to have less extra-articular leakage than yttrium-90 compounds. The aim of this study was to identify any increase in specific chromosome-type abnormalities, using published criteria, in patients following Sm-153 PHYP synovectomy of the knee. The 10 patients (five men, five women) in whom the analyses were performed had a mean age of 47 yr (range 28-70 yr). RESULTS: There was no increase in scored chromosome-type abnormalities after Sm-153 PHYP synovectomy. CONCLUSION: This study further supports the relative safety of Sm-153 PHYP compared to other radiopharmaceuticals.  (+info)

Sli15 associates with the ipl1 protein kinase to promote proper chromosome segregation in Saccharomyces cerevisiae. (6/802)

The conserved Ipl1 protein kinase is essential for proper chromosome segregation and thus cell viability in the budding yeast Saccharomyces cerevisiae. Its human homologue has been implicated in the tumorigenesis of diverse forms of cancer. We show here that sister chromatids that have separated from each other are not properly segregated to opposite poles of ipl1-2 cells. Failures in chromosome segregation are often associated with abnormal distribution of the spindle pole-associated Nuf2-GFP protein, thus suggesting a link between potential spindle pole defects and chromosome missegregation in ipl1 mutant cells. A small fraction of ipl1-2 cells also appears to be defective in nuclear migration or bipolar spindle formation. Ipl1 associates, probably directly, with the novel and essential Sli15 protein in vivo, and both proteins are localized to the mitotic spindle. Conditional sli15 mutant cells have cytological phenotypes very similar to those of ipl1 cells, and the ipl1-2 mutation exhibits synthetic lethal genetic interaction with sli15 mutations. sli15 mutant phenotype, like ipl1 mutant phenotype, is partially suppressed by perturbations that reduce protein phosphatase 1 function. These genetic and biochemical studies indicate that Sli15 associates with Ipl1 to promote its function in chromosome segregation.  (+info)

Inherited susceptibility to bleomycin-induced chromatid breaks in cultured peripheral blood lymphocytes. (7/802)

BACKGROUND: Susceptibility to bleomycin-induced chromatid breaks in cultured peripheral blood lymphocytes may reflect the way a person deals with carcinogenic challenges. This susceptibility (also referred to as mutagen sensitivity) has been found to be increased in patients with environmentally related cancers, including cancers of the head and neck, lung, and colon, and, in combination with carcinogenic exposure, this susceptibility can greatly influence cancer risk. The purpose of this study was to assess the heritability of mutagen sensitivity. METHODS: Heritability was determined by use of a maximum likelihood method that employed the FISHER package of pedigree analysis. Bleomycin-induced breaks per cell values for 135 healthy volunteers without cancer were determined. These individuals were from 53 different pedigrees and included 25 monozygotic twin pairs (n = 50), 14 pairs of dizygotes (twin pairs and siblings, n = 28), and 14 families selected on the basis of a first-degree relative who was successfully treated for head and neck cancer and who had no sign of recurrence for at least 1 year. All data were analyzed simultaneously, and different models of familial resemblance were fitted to the data. All P values are two-sided. RESULTS: Our results showed no evidence for the influence of a shared family environment on bleomycin-induced chromatid breaks. Genetic influences, however, were statistically significant (P =. 036) and accounted for 75% of the total variance. CONCLUSIONS: The high heritability estimate of the susceptibility to bleomycin-induced chromatid breaks indicates a clear genetic basis. The findings of this study support the notion that a common genetic susceptibility to DNA damage--and thereby a susceptibility to cancer--may exist in the general population.  (+info)

A functional assay for centromere-associated sister chromatid cohesion. (8/802)

Cohesion of sister chromatids occurs along the entire length of chromosomes, including the centromere where it plays essential roles in chromosome segregation. Here, minichromosomes in the budding yeast Saccharomyces cerevisiae are exploited to generate a functional assay for DNA sequences involved in cohesion. The centromeric DNA element CDEIII was found to be necessary but not sufficient for cohesion. This element was shown previously to be required for assembly of the kinetochore, the centromere-associated protein complex that attaches chromosomes to the spindle. These observations establish a link between centromere-proximal cohesion and kinetochore assembly.  (+info)

TY - JOUR. T1 - The DNA helicase ChlR1 is required for sister chromatid cohesion in mammalian cells. AU - Parish, Joanna L.. AU - Rosa, Jack. AU - Wang, Xiaoyu. AU - Lahti, Jill M.. AU - Doxsey, Stephen J.. AU - Androphy, Elliot J.. N1 - Copyright: Copyright 2011 Elsevier B.V., All rights reserved.. PY - 2006/12/1. Y1 - 2006/12/1. N2 - It has recently been suggested that the Saccharomyces cerevisiae protein Chl1p plays a role in cohesion establishment. Here, we show that the human ATP-dependent DNA helicase ChlR1 is required for sister chromatid cohesion in mammalian cells. Localization studies show that ChlR1 diffusely coats mitotic chromatin in prophase and then translocates from the chromatids to concentrate at the spindle poles during the transition to metaphase. Depletion of ChlR1 protein by RNA interference results in mitotic failure with replicated chromosomes failing to segregate after a pro-metaphase arrest. We show that depletion also results in abnormal sister chromatid cohesion, ...
Molecular Biology Sci Aug 4, 00 Pol : A DNA Polymerase Required for Sister Chromatid Cohesion Zhenghe Wang, Irene B. Castaño,* Alejandro De Las Peñas,* Carrie Adams, Michael F. Christman Establishment of cohesion between sister chromatids is coupled to replication fork passage through an unknown mechanism. Here we report that TRF4, an evolutionarily conserved gene necessary for chromosome segregation, encodes a DNA polymerase with -polymerase-like properties. A double mutant in the redundant homologs, TRF4 and TRF5, is unable to complete S phase, whereas a trf4 single mutant completes a presumably defective S phase that results in a failure of cohesion between the replicated sister chromatids. This suggests that TRFs are a key link in the coordination between DNA replication and sister chromatid cohesion. Trf4 and Trf5 represent the fourth class of essential nuclear DNA polymerases (designated DNA polymerase kappa) in Saccharomyces cerevisiae and probably in all eukaryotes. Department of ...
Meiotic chromosome condensation is a unique process, characterized by dramatic changes in chromosome morphology that are required for the correct progression of pairing, synapsis, recombination and segregation of sister chromatids. We used an antibody that recognizes a ser 10 phosphoepitope on histone H3 to monitor H3 phosphorylation during meiosis in maize meiocytes. H3 phosphorylation has been reported to be an excellent marker for chromosome condensation during mitotic prophase in animal cells. In this study, we find that on maize mitotic chromosomes only pericentromeric regions are stained; there is little staining on the arms. During meiosis, chromosome condensation from leptotene through diplotene occurs in the absence of H3 phosphorylation. Instead, the changes in H3 phosphorylation at different stages of meiosis correlate with the differences in requirements for sister chromatid cohesion at different stages. Just before nuclear envelope breakdown, histone H3 phosphorylation is seen first ...
Calpains form a family of Ca(2+)-dependent cysteine proteases involved in diverse cellular processes. However, the specific functions of each calpain isoform remain unknown. Recent reports have shown that calpain 2 (Capn2) is essential for cell viability. We have recently shown that Capn2 is a nuclear protease associated with chromosomes during mitosis in mammalian embryonic cells. We now report that Capn2 depletion impairs mitosis and induces apoptosis in murine cells. Low Capn2 levels induce chromosome alignment defects, the loss of histone H3 threonine 3 phosphorylation at centromeres, and premature sister chromatid separation. Thus, Capn2 may play a role in fundamental mitotic functions, such as the maintenance of sister chromatid cohesion.
Regulator of sister chromatid cohesion in mitosis which may stabilize cohesin complex association with chromatin. May couple sister chromatid cohesion during mitosis to DNA replication. Cohesion ensures that chromosome partitioning is accurate in both meiotic and mitotic cells and plays an important role in DNA repair. Plays a role in androgen-induced proliferative arrest in prostate cells.
Chromosome segregation, transcriptional regulation, and repair of DNA double-strand breaks require the cohesin protein complex. Cohesin holds the replicated chromosomes (sister chromatids) together to mediate sister chromatid cohesion. The mechanism of how cohesion is established is unknown. We found that in budding yeast, the head domain of the Smc3p subunit of cohesin is acetylated by the Eco1p acetyltransferase at two evolutionarily conserved residues, promoting the chromatin-bound cohesin to tether sister chromatids. Smc3p acetylation is induced in S phase after the chromatin loading of cohesin and is suppressed in G1 and G2/M. Smc3 head acetylation and its cell cycle regulation provide important insights into the biology and mechanism of cohesion establishment. ...
Segregation of homologous maternal and paternal centromeres to opposite poles during meiosis I depends on post-replicative crossing over between homologous non-sister chromatids, which creates chiasmata and therefore bivalent chromosomes. Destruction of sister chromatid cohesion along chromosome arms due to proteolytic cleavage of cohesins Rec8 subunit by separase resolves chiasmata and thereby triggers the first meiotic division. This produces univalent chromosomes, the chromatids of which are held together by centromeric cohesin that has been protected from separase by shugoshin (Sgo1/MEI-S332) proteins. Here we show in both fission and budding yeast that Sgo1 recruits to centromeres a specific form of protein phosphatase 2A (PP2A). Its inactivation causes loss of centromeric cohesin at anaphase I and random segregation of sister centromeres at the second meiotic division. Artificial recruitment of PP2A to chromosome arms prevents Rec8 phosphorylation and hinders resolution of chiasmata. Our data are
Shop Sister chromatid cohesion 1 protein ELISA Kit, Recombinant Protein and Sister chromatid cohesion 1 protein Antibody at MyBioSource. Custom ELISA Kit, Recombinant Protein and Antibody are available.
A multisubunit complex, called cohesin, containing Smc1p, Smc3p, Scc1p, and Scc3p, is required for sister chromatid cohesion in mitotic cells. We show here that Smc3p and a meiotic version of Scc1p called Rec8p are required for cohesion between sister chromatids, for formation of axial elements, for reciprocal recombination, and for preventing hyperresection of double-strand breaks during meiosis. Both Rec8p and Smc3p colocalize with chromosome cores independently of synapsis during prophase I and largely disappear from chromosome arms after pachytene but persist in the neighborhood of centromeres until the onset of anaphase II. The eukaryotic cells cohesion apparatus is required both for the repair of recombinogenic lesions and for chromosome segregation and therefore appears to lie at the heart of the meiotic process.
TY - JOUR. T1 - Phosphorylation-enabled binding of SGO1-PP2A to cohesin protects sororin and centromeric cohesion during mitosis. AU - Liu, Hong. AU - Rankin, Susannah. AU - Yu, Hongtao. PY - 2013/1. Y1 - 2013/1. N2 - Timely dissolution of sister-chromatid cohesion in mitosis ensures accurate chromosome segregation to guard against aneuploidy and tumorigenesis. The complex of shugoshin and protein phosphatase 2A (SGO1-PP2A) protects cohesin at centromeres from premature removal by mitotic kinases and WAPL in prophase. Here we address the regulation and mechanism of human SGO1 in centromeric cohesion protection, and show that cyclin-dependent kinase (CDK)-mediated, mitosis-specific phosphorylation of SGO1 activates its cohesion-protection function and enables its direct binding to cohesin. The phospho-SGO1-bound cohesin complex contains PP2A, PDS5 and hypophosphorylated sororin, but lacks WAPL. Expression of non-phosphorylatable sororin bypasses the requirement for SGO1-PP2A in centromeric ...
Two sister chromatids must be held together by a cohesion process from their synthesis during S phase to segregation in anaphase. Despite its pivotal role in accurate chromosome segregation, how cohesion is established remains elusive. Here, we demonstrate that yeast Rtt101‐Mms1, Cul4 family E3 ubiquitin ligases are stronger dosage suppressors of loss‐of‐function eco1 mutants than PCNA. The essential cohesion reaction, Eco1‐catalyzed Smc3 acetylation is reduced in the absence of Rtt101‐Mms1. One of the adaptor subunits, Mms22, associates directly with Eco1. Point mutations (L61D/G63D) in Eco1 that abolish the interaction with Mms22 impair Smc3 acetylation. Importantly, an eco1LGpol30A251V double mutant displays additive Smc3ac reduction. Moreover, Smc3 acetylation and cohesion defects also occur in the mutants of other replication‐coupled nucleosome assembly (RCNA) factors upstream or downstream of Rtt101‐Mms1, indicating unanticipated cross talk between histone modifications and ...
The Elg1 Clamp Loader Plays a Role in Sister Chromatid Cohesion. . Biblioteca virtual para leer y descargar libros, documentos, trabajos y tesis universitarias en PDF. Material universiario, documentación y tareas realizadas por universitarios en nuestra biblioteca. Para descargar gratis y para leer online.
Sister chromatid cohesion and homologue pairing at prometaphase I in solo; +, +; snm, and solo; snm mutants. X and Y chromosomes were recognized by probes again
View Notes - Homework _16 with answers from BIO Bio 5A at UC Riverside. Homework#16,02/20/09(Dr.MMG) 1. A cell containing 92 chromatids at metaphase of mitosis would, at its completion, produce two
HDAC inhibitors are a promising class of anticancer agents (Bolden et al., 2006; Johnstone and Licht, 2003; Yoshida et al., 2003). However, our understanding of how HDAC inhibitors act within cells and why different cell types respond in different ways is limited. We employed the fission yeast S. pombe as a model, because this organism is sensitive to HDAC inhibitors and contains a set of HDAC genes similar to those of mammalian organisms. In the present study, we focused on the mitotic functions of three TSA-sensitive HDACs in fission yeast. Our results suggest that Clr6 negatively regulates APC/C independently of the PKA pathway and Mad2. By contrast, Mis4, the cohesin loader, is positively controlled by HDACs. HDAC inhibitors thus reduce the level of Mis4 and facilitate the exit from mitosis via the assembly of APC/C complex, leading to the direction of sister chromatid separation in dividing cells (Fig. 7D).. Given the known anti-proliferation effects of HDAC inhibitors on tumour cells, our ...
Losada, A., Hirano, M., Hirano, T. (December 2002) Cohesin release is required for sister chromatid resolution, but not for condensin-mediated compaction, at the onset of mitosis. Genes & Development, 16 (23). pp. 3004-3016. ISSN 0890-9369 Losada, A., Hirano, M., Hirano, T. (July 1998) Identification of Xenopus SMC protein complexes required for sister chromatid cohesion. Genes and Development , 12 (13). pp. 1986-97. ISSN 0890-9369 (Print) Losada, A., Hirano, T. (February 2001) Intermolecular DNA interactions stimulated by the cohesin complex in vitro: Implications for sister chromatid cohesion. Current Biology, 11 (4). pp. 268-272. ISSN 0960-9822 Losada, A., Yokochi, T., Hirano, T. (May 2005) Functional contribution of Pds5 to cohesin-mediated cohesion in human cells and Xenopus egg extracts. J Cell Sci, 118 (Pt 10). pp. 2133-41. ISSN 0021-9533 (Print) ...
Chromatin, Chromatid, Chromsome Terminology - posted in General Biology Discussion: Some Questions to which I have found different/conflicting answers depending on what I have read or who I have talked to. Thanks in Advance. 1-Chromatin, chromosomes, and chromatid all consist of DNA AND some sort of proteins? 2-Is the following statement accurate: ALL types/forms of chromatin material and chromatids consist of chromosomes BUT not all types of chromosomes are chromatin or chromatids? 3-An...
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Involved in chromosome cohesion during cell cycle and in DNA repair. Central component of cohesin complex. The cohesin complex is required for the cohesion of sister chromatids after DNA replication. The cohesin complex apparently forms a large proteinaceous ring within which sister chromatids can be trapped. At anaphase, the complex is cleaved and dissociates from chromatin, allowing sister chromatids to segregate.
The present study evaluated the dynamics and regulatory mechanisms of single cohesin molecules. We found that Scc2‐Scc4‐dependent topological loading and cohesin ATPase activity (disengagement of the head domain) are crucial for cohesin translocation along DNA. Consistent with this finding, the ATPase‐dependent translocation of cohesin in budding yeast was described in a previous study (Hu et al, 2011). Although Wapl‐Pds5 promotes the dissociation of cohesin from DNA as previously described (Gandhi et al, 2006; Kueng et al, 2006) (Appendix Fig S2C), we showed that Wapl‐Pds5 renders DNA‐associated cohesin immobile (Fig 2A and B). Considering that the engagement of Smc head domains restrains cohesin movement (Fig 1F), Wapl‐Pds5 may contribute to the tightening of the cohesin ring by associating with SA1, Scc1, and/or Smc3 (Shintomi & Hirano, 2009; Hara et al, 2014; Murayama & Uhlmann, 2015; Ouyang et al, 2016). Therefore, Wapl‐Pds5 may have dual activities: anti‐establishment ...
Following replication of parental DNA template strands, sister chromatids are expected to have exactly the same DNA sequence except for mutations resulting from...
PubMed comprises more than 30 million citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.
Protein modification by ubiquitin and ubiquitin‐like modifiers (UBLs) plays key regulatory roles in numerous aspects of cell biology [1], [2]. Eukaryotic cells express more than a dozen UBLs, which share similar three‐dimensional structures with ubiquitin [1]. While the functions of several UBLs are well understood, others remain poorly characterized. Among these are UBL5 (known as Hub1 in yeast), which is unique among UBLs in that it lacks the C‐terminal glycine used for covalent conjugation to target proteins [3], [4]. However, UBL5 displays strong sequence conservation across eukaryotes, suggesting that it has a fundamentally important cellular function. Studies of Hub1 in the yeasts revealed that it is required for pre‐mRNA splicing. S. pombe Hub1 is an essential gene, and loss of Hub1 protein results in pre‐mRNA splicing defects, likely reflecting its interaction with the spliceosomal protein Snu66 (known as SART1 in mammalian cells) and perhaps other splicing factors [5], [6]. In ...
The Shugoshin/Aurora circuitry that controls the timely release of cohesins from sister chromatids in meiosis and mitosis is widely conserved among eukaryotes, although little is known about its function in organisms whose chromosomes lack a localized centromere. Here we show that Caenorhabditis elegans chromosomes rely on an alternative mechanism to protect meiotic cohesin that is shugoshin-independent and instead involves the activity of a new chromosome-associated protein named LAB-1 (Long Arm of the Bivalent). LAB-1 preserves meiotic sister chromatid cohesion by restricting the localization of the C. elegans Aurora B kinase, AIR-2, to the interface between homologs via the activity of the PP1/Glc7 phosphatase GSP-2. The localization of LAB-1 to chromosomes of dividing embryos and the suppression of mitotic-specific defects in air-2 mutant embryos with reduced LAB-1 activity support a global role of LAB-1 in antagonizing AIR-2 in both meiosis and mitosis. Although the localization of a GFP ...
If you have a question about this talk, please contact Duncan Simpson.. Cohesins mediate sister chromatid cohesion, which is essential for chromosome segregation and postreplicative DNA repair. In addition, cohesins appear to regulate gene expression and enhancer-promoter interactions. These noncanonical functions remained unexplained because knowledge of cohesin-binding sites and functional interactors in metazoans was lacking. We show that the distribution of cohesins on mammalian chromosome arms is not driven by transcriptional activity. Instead, mammalian cohesins occupy a subset of DNase I hypersensitive sites, many of which contain sequence motifs resembling the consensus for CTCF , a DNA -binding protein with enhancer blocking function and boundary element activity. We find cohesins at most CTCF sites and show that CTCF is required for cohesin localization to these sites. Recruitment by CTCF suggests a rationale for noncanonical cohesin functions and, because CTCF binding is sensitive to ...
Proper cohesion of sister chromatids is a prerequisite for the correct segregation of chromosomes during cell division. The cohesin multiprotein complex is required for sister chromatid cohesion. This complex is composed partly of two structural maintenance of chromosomes (SMC) proteins, SMC3 and either SMC1L2 or the protein encoded by this gene. Most of the cohesin complexes dissociate from the chromosomes before mitosis, although those complexes at the kinetochore remain. Therefore, the encoded protein is thought to be an important part of functional kinetochores. In addition, this protein interacts with BRCA1 and is phosphorylated by ATM, indicating a potential role for this protein in DNA repair. This gene, which belongs to the SMC gene family, is located in an area of the X-chromosome that escapes X inactivation ...
The sister chromatids of each chromosome split apart, and the spindle fibers pull each sister chromatid (now a separate chromosome) from each pair toward opposite poles, much as a rope-tow pulls a skier up a mountain. Telophase begins as sister chromatids reach opposite poles. Once the chromatids have reached opposite poles, the spindle apparatus falls apart, and the nuclear membrane re-forms. Mitosis is complete ...
Class cohesion is considered as one of the most important object-oriented software attributes. High cohesion is, in fact, a desirable property of software. Many different metrics have been suggested in the last several years to measure the cohesion of classes in object-oriented systems. The class of structural object-oriented cohesion metrics is the most in-vestigated category of cohesion metrics. These metrics measure cohesion on structural information extracted from the source code. Empirical studies noted that these metrics fail in many situations to properly reflect cohesion of classes. This paper aims at exploring the use of hierarchical clustering techniques to improve the measurement of cohesion of classes in object-oriented systems. The proposed approach has been evaluated using three particular case studies. We also used in our study three well-known structural cohesion metrics. The achieved results show that the new approach appears to better reflect the cohesion (and structure) of classes
The number of chromatids present during the prophase state of mitosis is double the number of chromosomes. The specific number depends on the number of chromosomes in the cell. Human beings, for...
1056 Hypersensitivity to radiation exposure has been suggested to be a risk factor for the development of breast cancer. In this case-control study of 323 young women (≤55 years) with newly diagnosed sporadic breast cancer and 326 cancer-free controls frequency-matched with patients on age, sex, and ethnicity, we examined the radiosensitivity as measured by the frequency of chromatid breaks induced by gamma-radiation exposure in the G2 phase of phytohemagglutinin-stimulated lymphocytes from short-term cultures of fresh blood samples. We found that the averaged chromatid breaks per cell from 50 well-spread metaphases were statistically significantly higher in breast cancer patients (mean = 0.51 breaks/cell, standard deviation = 0.22) than that in the controls (0.44 ± 0.16) (P value ,0.001). The frequency of chromatid breaks per cell above the median of control subjects was associated with twofold increased risk for breast cancer (OR = 2.02, 95% CI = 1.46 to 2.80). A dose-response relationship ...
i.sister chromatids split apart 2.Spindle draws them to opposite poles 3. Anaphase begins with the release of linker of sister chromatids iv. chromatids are pulled to the spindle pole v.sets of chromosomes to opposite ends of the ...
CRC is one of the most common malignant diseases globally (1). Recently, the function of SMC1 in CRC has attracted increasing attention, with evidence suggesting that the cohesin multiprotein complex is implicated in several diseases, including colorectal cancer (25-27). The cohesin multiprotein complex includes four major subunits: SMC1, SMC3, sister chromatid cohesion (SCC) protein 1 and SCC3. The cohesin multiprotein complex plays an important role in the regulation of transcription and development (28,29). SMC1 is an X-linked gene that can escape X-inactivation in humans, but is subject to X-inactivation in mice (30). Several mutations have been identified in the SMC1 gene, all of which are missense or small deletion mutations (12,20). Although SMC1 mutations have been reported in CRC (21,22), the role of SMC1 in CRC remains unclear. Therefore, elucidating how SMC1 is involved in CRC is of great importance.. In the present study, it was demonstrated that SMC1 was significantly upregulated in ...
Putative GTPase With A Role In Biogenesis Of RNA Pol II And PolIII; May Be Involved In Assembly Of RNA Polymerases II And III And In Their Transport Into The Nucleus; May Have A Role In Sister Chromatid Cohesion; Contains A Gly-Pro-Asn Motif In The G Domain; Similar To Npa3p And Gpn2p
then the second metaphase. this time the chromosomes instead of the bivalents line up on the equator of the spindle. second anaphase: The 2 chromatids (a chromosome is made of 2 chromatids) divide. they move away from each other. now last but not least the second telophase where again cytoplasm divides and 4 cells are formed. each with half the chromosomes needed: 23!! (in a human ...
In preparation for cell division (either meiosis or mitosis), the chromosomes replicate, forming an identical strand. These two strands remain side-by-s...
Although the molecular function of PDS5 is still under investigation, several organisms require diverse function of PDS5 for chromatid cohesion (Losada et al., 2005). For example, it may act as a regulator of the SMC ATPase through the HEAT motifs shared by SCC2 (Kimura and Hirano, 2000) and thereby modulate the dynamics of the cohesin ring. Alternatively, PDS5 may act as a scaffolding protein and promote protein-protein interactions between adjacent cohesin complexes (Losada et al., 2005). An examination of the chromosomes from Pds5B-deficient mouse cells did not show any abnormalities in sister chromatid cohesion (i.e. PSCS). This result was in contrast to those obtained in budding yeast, worm and Drosophila, where PDS5 plays an important role in chromosome segregation (Dorsett et al., 2005; Hartman et al., 2000; Wang et al., 2003). It is possible that our assay in which a total of 50 cells were examined may not have detected subtle defects. Indeed, only mild cohesion defects were found in ...
程金妹.,李建.,汤济鑫.,郝晓霞.,王志鹏.,...&刘以训.(2017).Merotelic Kinetochore Attachment in Oocyte Meiosis II Causes Sister Chromatids Segregation Errors in Aged Mice.Cell Cycle,16(15),1404-1413 ...
Summary The ring-shaped cohesin complex brings together distant DNA domains to maintain, express, and segregate the genome. Establishing specific chromosomal linkages depends on cohesin recruitment to defined loci. One such locus is the budding yeast centromere, which is a paradigm for targeted cohesin loading. The kinetochore, a multiprotein complex that connects centromeres to microtubules, drives the recruitment of high levels of cohesin to link sister chromatids together. We have exploited this system to determine the mechanism of specific cohesin recruitment. We show that phosphorylation of the Ctf19 kinetochore protein by a conserved kinase, DDK, provides a binding site for the Scc2/4 cohesin loading complex, thereby directing cohesin loading to centromeres. A similar mechanism targets cohesin to chromosomes in vertebrates. These findings represent a complete molecular description of targeted cohesin loading, a phenomenon with wide-ranging importance in chromosome segregation and, in ...
The cohesin complex ensures accurate sister chromatid segregation during cell division but it also seems to play an important role in development. For example, mutations in several cohesin components are associated with the human developmental disorder Cornelia de Lange syndrome (CdLS). Until now, there has been no animal model for this syndrome but, on p. 3191, Zhang and co-workers report that mice lacking the cohesin regulatory protein PDS5B are born with developmental abnormalities reminiscent of CdLS. Pds5B-deficient mice, like people with CdLS, exhibit abnormal skeletal patterning, heart defects and cleft palates, they report. Unexpectedly, however, the researchers did not find any chromosome cohesion defects in Pds5B-/- cells. Furthermore, they detected high PDS5B expression in post-mitotic neurons of wild-type mice, identified a DNA-binding domain in mouse PDS5B and showed that the protein localizes to the nucleolus. Overall, these results suggest that PDS5B and the cohesin complex might ...
Rationale: A cell has DNA strands of different replication ages because DNA replication is semi-conservative. Double-stranded DNA molecules possess one DNA strand that is one generation older than the other. Non-sister chromatids containing newly synthesized DNA and old DNA strands are non-randomly partitioned between mother and daughter cells. Stem cells are presumed to non-randomly segregate chromatids to determine cell fate of daughter cells, although experimental evidence is lacking. Resident cardiac progenitor cells (CPC) present in the adult heart have been used for cell-based treatment of myocardial damage but the factors determining the stemness and lineage commitment of these cells are poorly understood. Cardio protective kinase Pim-1 increases asymmetric cell division in vivo, proliferation and commitment of CPCs after adaptive transfer in pathological injury model but its role in non-random segregation is unknown.. Objective: Establish role of Pim-1 on non-random chromatid ...
Selective Chromatid Segregation Mechanism Explains the Etiology of Chromosome 11 Translocation-Associated Psychotic Disorders: A Review Abstract.
Cells possessing the incorrect number of chromosomes (referred to as aneuploid) can arise as a result of chromosome mis-segregation. Prevention of aneuploidy is especially important in germ cells, as these cells pass genetic information to the next generation, but also in pluripotent cells as these give rise to all tissues and cells of the offspring, including germ cells. Aneuploid conceptions have a detrimental effect on pregnancy outcomes, are surprisingly common in humans (estimated 10-30%), and are a leading cause of miscarriage and developmental disorders. In both meiosis and mitosis, accurate chromosome segregation relies on the correct orientation of sister chromatids during metaphase, which ensures bipolar spindle attachment. Newly replicated sister chromatids are able to align properly on the spindle due to cohesion holding them together. The protein complex responsible for sister chromatid cohesion (SCC) is called cohesin, and has specific subunits depending on its particular role. The ...
Separase Separase is a protein that is a cornerstone of cell division. Serperase is also known as Separin or Esp1. It allows for replicated chromosomes to be separated from their sister chromatids and pulled to opposite poles of the cell by the mitotic spindle, allowing for microfilaments to dissect the cell in half causing two genetically identical daughter cells from the single mother cell in mitosis or some haploid cells in Meiosis. The sister chromatids are held together by a protein called Cohesin, Separase catalyses and breaksdown cohesin allowing the sister chromatids to break apart, which in turn allows the mitotic spindle to draw the chromatids to either sides of the cell. Separase is crucial to the cell division process, not only does it physically separate the sister chromatids, it triggers the start of the anaphase period of cell division. Separase causes the cell to replicate accurately and on some occasions cause some problems if the protein is present or absent in excess ...
Cornelia de Lange syndrome (CdLS) is a multiple malformation disorder characterized by dysmorphic facial features, mental retardation, growth delay and limb reduction defects. We indentified and characterized a new gene, NIPBL, that is mutated in individuals with CdLS and determined its structure an …
Free, official coding info for 2018 ICD-10-CM O45.021 - includes detailed rules, notes, synonyms, ICD-9-CM conversion, index and annotation crosswalks, DRG grouping and more.
Free, official coding info for 2018 ICD-10-CM O45.023 - includes detailed rules, notes, synonyms, ICD-9-CM conversion, index and annotation crosswalks, DRG grouping and more.
This gene encodes the homolog of the Drosophila melanogaster Nipped-B gene product and fungal Scc2-type sister chromatid cohesion proteins. The Drosophila protein facilitates enhancer-promoter communication of remote enhancers and plays a role in developmental regulation. It is also homologous to a family of chromosomal adherins with broad roles in sister chromatid cohesion, chromosome condensation, and DNA repair. The human protein has a bipartite nuclear targeting sequence and a putative HEAT repeat. Condensins, cohesins and other complexes with chromosome-related functions also contain HEAT repeats. Mutations in this gene result in Cornelia de Lange syndrome, a disorder characterized by dysmorphic facial features, growth delay, limb reduction defects, and mental retardation. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2008 ...
Baxter J, Aragón L, 2010, Physical linkages between sister chromatids and their removal during yeast chromosome segregation., Cold Spring Harb Symp Quant Biol, Vol: 75, Pages: 389-394 The fidelity of chromosome inheritance is of paramount importance to all living organisms. In eukaryotic cells, the strategy to ensure physical segregation of chromosomes to daughter cells relies on two basic steps ordered in time: an initial linkage, or cohesion, of sister chromatids and its timely and complete dissolution during anaphase. The current view is that these two basic steps are accomplished around the regulation of a protein complex called cohesin that serves as clamp brackets distributed at intervals throughout the genome. However, many of the DNA metabolic activities during interphase also produce physical linking of chromatids. For example, during replication, intertwines between sister chromatids are formed. Here, we review our understanding of the processes that generate physical linkages ...
CHROMOSOMES undergo dynamic behaviors during mitosis to enable the precise separation of the two replicated sister chromatids. It is vital that the replicated sister chromatids are separated successfully. There are two crucial prerequisites for accurate segregation: (1) cohesion between the replicated chromatids must be maintained until anaphase and (2) compaction of the chromosomes into a manageable form, condensation, must be completed prior to metaphase. These processes require two major protein complexes, the cohesin and condensin complexes. Each of these complexes is founded upon a heterodimer of structural maintenance of chromosomes (SMC) proteins, which are chromosome-associated ATPases (Hirano 1998, 2002). Also within each complex are two or three non-SMC subunits, which attribute specific functions to the SMC holocomplex. Despite a similar structural paradigm, the condensin and cohesin complexes are functionally distinct. Although each complex was originally identified for unique ...
The Frequency and Clinical Significance of Sister Chromatid Exchange in the Lymphocyte of Gastric Cancer Patient Exposed to Hypoxia
(KudoZ) English to German translation of sister chromatid exchange: Schwesterchromatid-Austausch [alprostadil product characteristics - Medical: Pharmaceuticals (Medical)].
The structure that hold sister chromatids together in eukaryotic chromosomes. It is visible as the main constriction point on the chromosome. The centromere is the point of attachment for the fibers that pull sister chromatids apart during mitosis.
Knockdown of several components of the spliceosome results in premature loss of SCC, thus preventing the stable attachment of microtubules and the bi‐orientation of chromatids (van der Lelij et al, 2014; Sundaramoorthy et al, 2014; Watrin et al, 2014). Some of these factors, such as SNW1 (a component of a NTC‐related subcomplex), PRPF8 (a key coordinator of splicing catalysis associated with U5 snRNP) or MAFP1 (which associates transiently in the context of spliceosomal rearrangements previous to catalysis), are believed to have core functions in the splicing process. Their impact on cell division, however, raised the possibility that they display specific functions in mitotic progression different from splicing (Hofmann et al, 2010). To address this issue, Petronczki and colleagues analyzed in detail a set of 33 spliceosome components previously reported to alter mitosis when downregulated (Neumann et al, 2010). In this new study, knockdown of 26 out of these 33 splicing factors tested ...
Homologous chromosomes do not pair during mitosis, so there is no opportunity for crossing over to occur. Crossing over between non-sister chromatids of homologous chromosomes occurs in meiosis...
Extensive biochemical and molecular analyses have shown that BubR1 plays a central role in spindle checkpoint activation (5 , 15 , 16) . It both coordinates the interaction of Bub3, Mad1, Mad2, and CENP-E with kinetochores and contributes to inhibition of APC activity during activation of this checkpoint. The APC is an E3 ubiquitin ligase that mediates the polyubiquitination of securin, thereby targeting it for degradation by the proteosome (16) . Securin binds to and inhibits the proteolytic activity of separase, which destroys the link between sister chromatids by cleaving the chromatid cohesin factor Scc1. Degradation of securin is required for the separation of sister chromatids during mitosis. Reduced levels of securin in BubR1+/− MEFs are closely correlated with BubR1 deficiency as well as with its activation status (Fig. 1C) ⇓ . Moreover, down-regulation of BubR1 via RNA interference resulted in almost complete disappearance of securin (Fig. 1D) ⇓ , strongly suggesting that BubR1 ...
The exchange of genetic material means that new combinations of genes are created on two of the four chromatids: Stretches of DNA with maternal gene copies are mixed with stretches of DNA with paternal copies. This creation of new gene combinations is called recombination and is very important for evolution, since it increases the amount of genetic material that evolution can act upon. A statistical technique known as linkage analysis uses the frequency of recombination to infer the location of genes, such as those that increase a persons risk for certain diseases.. At the beginning of metaphase I, the nuclear envelope has dissolved, and specialized protein fibers called microtubules have formed a spindle apparatus, as also occurs in the metaphase of mitosis. These microtubules then attach to the kinetochore protein disks on the two centromeres of the homologous pair of chromosomes. However, there is an important difference between mitosis and meiosis in the way this attachment occurs. In ...
Cohesin complexes mediate sister-chromatid cohesion in dividing cells but may also contribute to gene regulation in postmitotic cells. How cohesin regulates gene expression is not known. Here we describe cohesin-binding sites in the human genome and show that most of these are associated with the CC …
View Notes - Handout 7 (for students) from BICD BICD100 at UCSD. Duyen-Anh Pham BICD 100 [email protected] Key Terms : • Chromosome vs. Chromatid vs. chromatinCentromere and Kinetochore •
During its lifetime a nucleus may be broken down, either in the process of cell division or as a consequence of apoptosis, a regulated form of cell death. During these events, the structural components of the nucleus-the envelope and lamina-are systematically degraded. During the cell cycle the cell divides to form two cells. In order for this process to be possible, each of the new daughter cells must have a full set of genes, a process requiring replication of the chromosomes as well as segregation of the separate sets. This occurs by the replicated chromosomes, the sister chromatids, attaching to microtubules, which in turn are attached to different centrosomes. The sister chromatids can then be pulled to separate locations in the cell. However, in many cells the centrosome is located in the cytoplasm, outside the nucleus, the microtubules would be unable to attach to the chromatids in the presence of the nuclear envelope.[44] Therefore the early stages in the cell cycle, beginning in ...
Rec8 is a prominent component of the meiotic prophase chromosome axis that mediates sister chromatid cohesion, homologous recombination and chromosome synapsis. Here, we explore the prophase roles of Rec8. (i) During the ...
Separase, A Caspase-like Cysteine Protease; Promotes Sister Chromatid Separation By Mediating Dissociation Of The Cohesin Scc1p From Chromatin; Inhibits Protein Phosphatase 2A-Cdc55p To Promote Mitotic Exit; Inhibited By Pds1p; Relative Distribution To The Nucleus Increases Upon DNA Replication Stress
When you make the baby, call your teacher over and explain how you did it. Again, the student will run the meiosis animation, looking at the cell in the big meiosis window with Crossover Controlled option on. When the animation stops in the middle of the process, the student will be told to click on a chromatid. This time, s/he should search for the chromatid that has the M allele. By clicking on one chromatid with an M and on one with an m, the student will see the exchange take place that results in a gamete containing a chromosome with a B+ and an M allele. S/he should then follow the same process for the cell from the other parent. After s/he chooses and fertilizes the proper gametes, the resulting baby should be normal for both sickle cell and methemoglobin. There are a couple of places where problems could arise in this exercise. If the student clicks on the allele itself, nothing will happen and you will hear cries of anguish. Similarly, if s/he clicks too close to the centromere ...
Reactome is pathway database which provides intuitive bioinformatics tools for the visualisation, interpretation and analysis of pathway knowledge.
An illustration of chromosome, with its parts. (1) Chromatid. One of the two identical parts of the chromosome after S phase. (2) Centromere. The point where the two chromatids touch, and where the microtubules attach. (3) Short arm (4) Long arm ...
A chromosome doesnt code for anything, it the gene which codes for proteins. A gene is a section of DNA, it is a section of the long stranded DNA, it consists of a particular sequence of bases. Codons, which are 3 bases, they code for one amino acid. A chromosome is just a long strand of DNA, it has many genes i.e. section of DNA, sections of base sequences which code for polypeptides. Polypeptides such as enzymes, which in turn control the development of an organism and the reactions which take place ...
Function: Corrects defective DNA strand-break repair and sister chromatid exchange following treatment with ionizing radiation and alkylating agents ...
China Cohesion Force Demonstration (Educational equipment), Find details about China Educational Equipment, Teaching Instrument from Cohesion Force Demonstration (Educational equipment) - Yuyao Shenma Teaching Instrument Whole Set Co., Ltd.
The special process of cell division by which part exchange takes place between the non-sister chromatids of homologous chromosomes is known as crossing ov
Oh ... I see now ... when the chromosomes replicate they become chromatids. Then they are the same and that makes them sisters. That makes alot of sense. And it means I shouldnt doubt myself lol. GAH it makes too much sense now that I look back at it. Thank you soooo very much for the help ...
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Imagine over your head a sprinkling of light, like stars...the Big Dipper and zoom in on the North Star. ( Can happen that you feel that the star becomes immensely large like a blanket spread over the horizon, shiny silvery white, which makes sense as it lies aligned with the earths axis in the middle of the corona. ) ...
CHINA, the worlds largest community, is today struggling both to find its own internal cohesion and to establish a new relationship with the outsi
Free Essay: Cohesive Groups In general terms, a group is said to be in a state of cohesion when its members possess bonds linking them to one another and to...
... where two identical sister chromatids are most closely in contact. When cells enter mitosis, the sister chromatids (the two ... "Sister chromatid cohesion". Genetics Home Reference. United States National Library of Medicine. May 15, 2011. "p + q = Solved ... The centromere is the part of a chromosome that links a pair of sister chromatids (a dyad). During mitosis, spindle fibers ... Cell biology Chromatid Diploid Genetics Monopolin Pollard, T.D. (2007). Cell Biology. Philadelphia: Saunders. pp. 200-203. ISBN ...
Past methods have been used to track the inheritance patterns of chromatids on a per-strand basis and elucidate the process of ... Unfortunately, this method is found to have poor resolution as it can only be observed at the chromatid level. CO-FISH, or ... If the cell was sequenced after more than one generation, a pattern of chromatid assortment can be ascertained for the ... Strand-seq was initially proposed as a tool to identify sister chromatid exchanges. Being a process that is localized to ...
Each chromosome still consists of two chromatids. Soni, NK; Soni, Vandana. Fundamentals of Botany. Tata McGraw-Hill Education. ...
... is a meiosis-specific component of the cohesin complex that binds sister chromatids in preparation for the two divisions ... However, Rec8 is maintained at centromeres so that sister chromatids are kept joined until anaphase of meiosis II, at which ... Rec8 is sequentially removed from sister chromatids. It is removed from the arms of chromosomes in the first division - ... In the mouse, the homologous protein is a key component of the meiotic cohesion complex, which regulates sister chromatid ...
Each chromatid has its own kinetochore, and all of the microtubules that are bound to kinetochores of sister chromatids radiate ... As it happens that sister chromatids are attached together and both kinetochores are located back-to-back on both chromatids, ... At the metaphase to anaphase transition, this cohesion between sister chromatids is dissolved, and the separated chromatids are ... the two chromatids) until anaphase. At this point, the two sister chromatids separate and travel to opposite poles in the ...
Sister-chromatid exchange assay; Allium assay; Alamar blue assay; Trypan blue assay. Primary cell lines establishment. Projects ... cytokinesis-block micronucleus cytome assay and sister chromatids exchange assay. Evaluation of cytotoxic and cytostatic ...
Human homologs of a Saccharomyces cerevisiae complex involved in sister chromatid cohesion establishment". J. Biol. Chem. 278 ( ... Sister-chromatid cohesion factors • Protein kinases • Cell-cycle regulators • Apoptotic factors for details see PCNA has been ...
It has a role in attaching to the kinetochores, structures on the chromatids where microtubules attach. Shugoshin has a ... It senses tension between sister chromatids during mitosis, and it degrades when they separate preventing cell cycle arrest and ... It does this by preventing the cohesin complex which regulates chromatid separation from prematurely dissociating. Shugoshin ... This results in the sister chromatids remaining tethered. Shugoshin also acts as a spindle checkpoint component. ...
Because sister chromatids after DNA replication hold each other by Cohesin rings, there is the only chance for the ... Therefore, the resulting sister chromatids cannot separate from each other and cannot divide into 2 daughter cells. When ... The replication factories perform disentanglement of sister chromatids. The disentanglement is essential for distributing the ... chromatids into daughter cells after DNA replication. ...
It has duplicated its DNA, so that each chromosome has two chromatids, i.e. 92 chromatids all in all (4C). When meiosis I is ... As such, there is only one chromatid on each chromosome, making the total quantity of chromatids 46. This is twice the number ... However, each chromosome still has two chromatids, making a total of 46 chromatids (1N but 2C). The secondary oocyte continues ... Each chromosome is split between the two ootids, leaving only one chromatid per chromosome. Thus, there are 23 chromatids in ...
Sister chromatids are disentangled and resolved from one another. Chromosomes also shorten in length, up to 10,000 fold in ... By the end of DNA replication, sister chromatids are bound together in an amorphous mass of tangled DNA and protein that would ... Aurora B is a member of the chromosomal passenger complex and mediates chromosome-microtubule attachment and sister chromatid ... This gives mitotic chromosomes the classic "X" shape seen in karyotypes, with each condensed sister chromatid linked along ...
In nondisjunction, sister chromatids fail to separate during anaphase. One daughter cell receives both sister chromatids from ... The microtubules then contract to pull the sister chromatids of each chromosome apart. Sister chromatids at this point are ... Each chromosome has two chromatids. The two chromatids are joined at the centromere. Gene transcription ceases during prophase ... The lagging chromatid is excluded from both nuclei and is lost. Therefore, one of the daughter cells will be monosomic for that ...
If a crossover event between non-sister chromatids affects that locus, then both homologous chromosomes will have one chromatid ... If the chromatids containing different alleles line up on the same side of the plate, then the resulting daughter cells will ... However, if chromatids containing the same alleles line up on the same side, the daughter cells will be homozygous at that ... These include sister chromatid exchange and mechanisms related to DNA double strand break repair by homologous recombination ...
... each sister chromatid segregates to opposite poles. Without cohesin, the cell would be unable to control sister chromatid ... Cohesins hold sister chromatids together after DNA replication until anaphase when removal of cohesin leads to separation of ... Dissociation of sister chromatids cohesion defines anaphase onset, which establishes two sets of identical chromosomes at each ... The two rings are connected to each other through formation of a bridge that holds the two sister chromatids together. The ...
Cohesin: The cohesin complex was initially discovered as a key player in mitosis, binding sister chromatids together to ensure ... Mehta, GD; Kumar, R; Srivastava, S; Ghosh, SK (2 August 2013). "Cohesin: functions beyond sister chromatid cohesion". FEBS ...
Nasmyth has since shown that cohesin forms a ring, that sister chromatids are held together within this ring and that they are ... Using temperature-sensitive mutants of the APC/C he found several genes which are required for sister chromatid cohesion which ... Irniger, S.; Piatti, S.; Michaelis, C.; Nasmyth, K. (21 April 1995). "Genes involved in sister chromatid separation are needed ... Nasmyth, K; Peters, J. M.; Uhlmann, F (2000). "Splitting the chromosome: Cutting the ties that bind sister chromatids". Science ...
Uhlmann, F. (2007). "What is your assay for sister-chromatid cohesion?". The EMBO Journal. 26 (22): 4609-4618. doi:10.1038/sj. ... Nasmyth, K; Peters, J. M.; Uhlmann, F (2000). "Splitting the chromosome: Cutting the ties that bind sister chromatids". Science ... subscription required) Uhlmann, F; Lottspeich, F; Nasmyth, K (1999). "Sister-chromatid separation at anaphase onset is promoted ... to establish cohesion between sister chromatids during DNA replication". Genes & Development. 13 (3): 320-33. doi:10.1101/gad. ...
Losada A, Hirano M, Hirano T (1998). "Identification of Xenopus SMC protein complexes required for sister chromatid cohesion". ... Guacci V, Koshland D, Strunnikov A (1998). "A direct link between sister chromatid cohesion and chromosome condensation ... A pair of SMC1 and SMC3 constitutes the core subunits of the cohesin complexes involved in sister chromatid cohesion. Likewise ... chromosomal proteins that prevent premature separation of sister chromatids". Cell. 91 (1): 35-45. doi:10.1016/S0092-8674(01) ...
During metaphase, sister chromatids are linked by intact cohesin complexes. When securin undergoes ubiquitination by the APC/C ... In this manner, cyclin A can be degraded while cyclin B and securin are degraded only once sister chromatids have achieved bi- ... The subunit Apc15 plays an important role in APC/CCdc20 activation following the bi-orientation of sister chromatids across the ... Once degraded, separin is released, cohesin is degraded and sister chromatids are prepared to move to their respective poles ...
Tang Z, Sun Y, Harley SE, Zou H, Yu H (Dec 2004). "Human Bub1 protects centromeric sister-chromatid cohesion through Shugoshin ... A physical mechanism that guarantees the accurate segregation of sister chromatids during mitosis arises from the ring shaped ... Wang X, Dai W (Oct 2005). "Shugoshin, a guardian for sister chromatid segregation". Experimental Cell Research. 310 (1): 1-9. ... This complex encircles the two sister chromatids and resists the pulling force of microtubules. The characteristic X-shape ...
Condensation during the G2 phase yields long chromosomes with two chromatids. PCC was first reported in 1968, of viral-infected ...
In these cells chiasma occurs and sister chromatids are partly held together by cohesions; when cell division occurs, the ... During normal mitosis, sister chromatids separate into two identical daughter cells. In meiosis is a diploid cell (2N) ... sister chromatids are sheared and mis-segregated which results in an aneuploid state. Melanoma may be prone to meiomitosis due ...
Each chromosome is in a haploid state and consists of two sister chromatids; however, the chromatin of the sister chromatids is ... These copies are referred to as sister chromatids and are attached by DNA element called the centromere. The main events of ... The mitotic spindle is of great importance in the process of mitosis and will eventually segregate the sister chromatids in ... Condensed chromosomes consist of two sister chromatids joined at the centromere. During prophase in animal cells, centrosomes ...
In keeping with the stem cell hypothesis, the more undifferentiated daughter typically inherited the chromatids with the older ... Nonrandom segregation of sister chromatids in Vici faba and Triticum boeoticum. Proc. Natl. Acad. Sciences 58: 352-359. Merok, ... Left-Right Dynein Motor Implicated in Selective Chromatid Segregation in Mouse Cells. Science 5 January 2007: Vol. 315. no. ... DNA seen in the daughter with less label corresponded to the amount that would have arisen from sister-chromatid exchange. ...
... called chromatids or sister chromatids) joined by a centromere. Eukaryotes (cells with nuclei such as those found in plants, ... These sister chromatids are conjoined twins the result of DNA replication. The centromere helps the chromatids attach to the ... so that each daughter cell inherits one set of chromatids. Once the cells have divided, the chromatids are uncoiled and DNA can ... The two chromatids are made up of very thin chromatin fibres which are made up of 40% DNA and 60% histone proteins Each ...
Uhlmann, F. (2007). "What is your assay for sister-chromatid cohesion?". The EMBO Journal. 26 (22): 4609-4618. doi:10.1038/sj. ...
2007). "PHB2 protects sister-chromatid cohesion in mitosis". Curr. Biol. 17 (15): 1356-61. doi:10.1016/j.cub.2007.07.009. PMID ...
It can cause chromatid aberrations in cell models. Altretamine Luippold HE, Gooch PC, Brewen JG (February 1978). "The ...
In addition to the fluorescent reference beads, signal strength from sister chromatids should be equal and therefore can be ... By using different colored unidirectional PNA probes, it becomes possible to uniquely label sister chromatids,. Poon, SSS. and ... "Identification of sister chromatids by DNA template strand sequences." Nature (2010)463:93-98.. ...
... is a protein structure on chromatids where the spindle fibers attach during cell division to pull sister chromatids apart. ... syntelic: both chromatids are anchored to MTs emanating from the same pole; this situation does not generate centromeric ... If it is not corrected, the chromatid bound to both poles will remain as a lagging chromosome at anaphase, and finally will be ... Their proteins help to hold the sister chromatids together and also play a role in chromosome editing. The kinetochore forms in ...
A sister chromatid refers to the identical copies (chromatids) formed by the replication of a chromosome, with both copies ... In other words, a sister chromatid may also be said to be one-half of the duplicated chromosome. A pair of sister chromatids ... Biorientation Sister chromatid exchange Kadyk, Lc; Hartwell, Lh (Oct 1992). "Sister chromatids are preferred over homologs as ... There is evidence that, in some species, sister chromatids are the preferred template for DNA repair. Sister chromatid cohesion ...
Chromatids may be sister or non-sister chromatids. A sister chromatid is either one of the two chromatids of the same ... see articles Sister chromatids and Sister chromatid exchange). Non-sister chromatids, on the other hand, refers to either of ... Sister chromatid exchange (SCE) is the exchange of genetic information between two sister chromatids. SCEs can occur during ... A pair of sister chromatids is called a dyad. Once sister chromatids have separated (during the anaphase of mitosis or the ...
Meiotic sister chromatid recombination.. Petes TD1, Pukkila PJ.. Author information. 1. Department of Biology, University of ...
During the anaphase of mitosis and meiosis the sister chromatids are pulled apart by the kinetochore microtubules attached to ... During meiosis, homologous sets of sister chromatids get together to form the tetrad, where they cross over. Again, having the ...
chromatid (thing). See all of chromatid, there is 1 more in this node. ...
... but their satisfaction is not sufficient to guarantee no chromatid interference. Models can be constructed in which chromatid ... Statistical analysis of chromatid interference.. H Zhao, M S McPeek and T P Speed ... Statistical analysis of chromatid interference.. H Zhao, M S McPeek and T P Speed ... Statistical analysis of chromatid interference.. H Zhao, M S McPeek and T P Speed ...
So thats one chromatid and this is another chromatid. Sometimes theyll call them sister chromatids. Maybe they should call ... Now, then the next word is, well, what is this chromatid thing? What is this chromatid thing? Actually, just in case I didnt, ... You could call it a chromatid, although that tends to not be the convention. People start talking about chromatids once you ... So whats a chromatid? When DNA replicates-- so lets say that was my DNA before, right? When its just in its normal state, I ...
HR supresses tumorigenesis1, but is restricted to the S and G2 phases of the cell cycle when a sister chromatid is present2. ... routing only DSBs within sister chromatids to HR. Nakamura et al. show that DNA repair pathway choice and initiation of ... linking DSB repair pathway choice directly to sister chromatid availability. We identify the ankyrin repeat domain of BRCA1- ... HR supresses tumorigenesis1, but is restricted to the S and G2 phases of the cell cycle when a sister chromatid is present2. ...
Sister chromatids are associated from their formation until their disjunction. Cohesion between sister chromatids is provided ... Recombination, sister chromatid cohesion and the relation between the two processes must be regulated differently in mitosis ... Sister chromatid cohesion and recombination in meiosis.. van Heemst D1, Heyting C. ... Sister chromatid cohesion is intimately linked to other aspects of chromosome behaviour and metabolism, in particular ...
KudoZ) English to German translation of sister chromatid exchange: Schwesterchromatid-Austausch [alprostadil product ... sister chromatid exchange. Alprostadil showed no evidence of mutagenicity in vitro in the Ames bacterial reverse mutation test ...
The ord gene product may prevent premature sister-chromatid separation by promoting cohesion of the sister chromatids in a ... Sister-chromatid misbehavior in Drosophila ord mutants.. W Y Miyazaki and T L Orr-Weaver ... Sister-chromatid misbehavior in Drosophila ord mutants.. W Y Miyazaki and T L Orr-Weaver ... Sister-chromatid misbehavior in Drosophila ord mutants.. W Y Miyazaki and T L Orr-Weaver ...
A chromatid is one of two identical copies of DNA making up a chromosome that are joined at their centromeres, for the process ... Thus there are 46 chromatids (2xN) Alternatively, a haploid cell with two chromatids per chromosome also has 46 chromatids. ... Thus, there are 23 chromatids (1xN) Etymology. The term chromatid was proposed by McClung (1900) for each of the four threads ... In a cell with 4N chromatids, there are 23 chromosome pairs (46 chromosomes), and each chromosome has 2 chromatids. Thus, there ...
The protein complex cohesin keeps the sister chromatids together, but how it interacts with the DNA was unknown. A crystal ... In cell division, after replication of the cells chromosomes, the two copies, called sister chromatids, must be kept together ...
These include the individualization and compaction of the two copies of replicated chromosomes (the sister chromatids) and ... Building and breaking bridges between sister chromatids Bioessays. 2003 Dec;25(12):1178-91. doi: 10.1002/bies.10361. ... These include the individualization and compaction of the two copies of replicated chromosomes (the sister chromatids) and ... Cohesin is required for holding sister chromatids together whereas condensin, together with topoisomerase II, has an important ...
Gene Ontology Term: sister chromatid biorientation. GO ID. GO:0031134 Aspect. Biological Process. Description. The cell cycle ... process in which sister chromatids establish stable attachments to microtubules emanating from opposite spindle poles.. ...
Linking Sister Chromatid Cohesion and Apoptosis: Role of Rad21 Debananda Pati, Nenggang Zhang, Sharon E. Plon ... Mrc1 Is Required for Sister Chromatid Cohesion To Aid in Recombination Repair of Spontaneous Damage Hong Xu, Charles Boone, ... Caenorhabditis elegans EVL-14/PDS-5 and SCC-3 Are Essential for Sister Chromatid Cohesion in Meiosis and Mitosis Fang Wang, ... Bloom Helicase and DNA Topoisomerase IIIα Are Involved in the Dissolution of Sister Chromatids Masayuki Seki, Takayuki Nakagawa ...
1) Chromatid - one of the two parts of the chromosome after duplication. (2) Centromere - the point where the two chromatids ... When the centromere divides, the chromatids become separate chromosomes.[1] Each of the two daughter chromatids contains the ... Chromatids are the daughter strands of a duplicated chromosome which are joined by a single centromere. ... But in meiosis, crossing over (exchanges) take place between two of the non-sister chromatids. This has profound consequences: ...
Gene Ontology Term: meiotic sister chromatid separation. GO ID. GO:0051757 Aspect. Biological Process. Description. The process ... meiotic sister chromatid resolution View GO Annotations in other species in AmiGO ... in which sister chromatids are physically detached from each other during meiosis.. Synonyms. ...
Did it also play a part in chromatid cohesion in the worm? Once again, RNA interference showed it did. Finally, if MAU-2 has a ... Exploring mechanics of chromatid cohesion. By PLoS Biology, Jul 5, 2006 - 2:52:37 PM. ... To test whether human MAU-2 had a similar role in linking sister chromatids, the authors used RNA interference to diminish MAU- ... These findings shed light on the mechanics of chromatid cohesion, and will be useful for further elucidating the complex means ...
Dubey and Marc Gartenberg reveal a surprising new role for tDNAs and RNA polymerase III-associated proteins in sister chromatid ... Sister chromatid cohesion (the binding together of the two identical copies of each chromosome that are formed during ... Sister chromatid cohesion is mediated by a multi-subunit protein complex called cohesin. Inside the cell nucleus, cohesin ... Coming together: tDNAs, RNA pol III and chromatid cohesion. Cold Spring Harbor Laboratory ...
Human Lymphocyte Sister Chromatid Exchange Lens Culinaris Sister Chromatid Exchange Frequency Cell Cycle Duration ... Kato, H., and A.A. Sandberg (1977) The effect of sera on sister chromatid exchanges in vitro. Exp. Cell Res. 109:445-448.PubMed ... Taylor, J.H. (1958) Sister chromatid exchanges in tritium-labeled chromosomes. Genetics 43:515-529.PubMedGoogle Scholar ... Speit, G. (1980) Effect of temperature on sister chromatid exchanges. Human Genet. 55:333-336.CrossRefGoogle Scholar ...
... characterized by high frequencies of telomeric sister chromatid exchanges (T-SCEs). Mechanisms of ALT activation are still ... Subtelomeric DNA hypomethylation is not required for telomeric sister chromatid exchanges in ALT cells. *G Tilman1. , ... Tilman, G., Loriot, A., Van Beneden, A. et al. Subtelomeric DNA hypomethylation is not required for telomeric sister chromatid ... Detection of telomeric sister chromatid exchanges in tumor-derived and SV40-immortalized cell lines. (a) T-SCEs detected by CO- ...
Pol : A DNA Polymerase Required for Sister Chromatid Cohesion. Rcjohnsen rcjohnsen at aol.com Wed Aug 9 16:27:13 EST 2000 * ... This suggests that TRFs are a key link in the coordination between DNA replication and sister chromatid cohesion. Trf4 and Trf5 ... Molecular Biology Sci Aug 4, 00 Pol : A DNA Polymerase Required for Sister Chromatid Cohesion Zhenghe Wang, Irene B. Castaño,* ... Alejandro De Las Peñas,* Carrie Adams, Michael F. Christman Establishment of cohesion between sister chromatids is coupled to ...
Localization of Sister Chromatid Exchanges in Human Chromosomes Message Subject. (Your Name) has forwarded a page to you from ... The frequency of sister chromatid exchanges among chromosomes correlates with chromosome length. Exchanges appear to occur ... The bromodeoxyuridine; sensitivity of 33258 Hoechst fluorescence allows microfluorometric analysis of sister chromatid ...
The induction of sister chromatid exchange (SCE) has been proposed as a predictive test for the identification of mutagens/ ... 2: Sister Chromatid Exchange, A.A. Sandberg, ed. Alan R. Liss, New York, pp. 297-315.Google Scholar ... Kanda, N., and H. Kato (1979) In vivo sister chromatid exchange in cells of various organs of the mouse. Chromosoma 74:229-305. ... In: Tice R.R., Hollaender A., Lambert B., Morimoto K., Wilson C.M. (eds) Sister Chromatid Exchanges. Springer, Boston, MA. * ...
Sister chromatid cohesion is essential for chromosome segregation and is mediated by cohesin bound to DNA. Cohesin-DNA ... Sororin Mediates Sister Chromatid Cohesion by Antagonizing Wapl Cell. 2010 Nov 24;143(5):737-49. doi: 10.1016/j.cell.2010.10. ... Sister chromatid cohesion is essential for chromosome segregation and is mediated by cohesin bound to DNA. Cohesin-DNA ...
Posts about sister chromatids written by Liz Belasic ...
Crossing over between non-sister chromatids of homologous chromosomes occurs in meiosis... ... Since this replication is meant to result in identical cells, non-sister chromatids are never formed, and crossing over cannot ... During prophase I, the two chromosomes align (two sets of identical sister chromatids), and crossing over occurs at a chiasma ... During mitosis, chromosomes duplicate to result in identical sister chromatids in prophase. These then align in the middle of ...
A sister chromatid refers tae the identical copies (chromatids) formed bi the replication o a chromosome, wi baith copies jynt ... Taen frae "https://sco.wikipedia.org/w/index.php?title=Sister_chromatids&oldid=683489" ...
  • Molecular Biology Sci Aug 4, 00 Pol : A DNA Polymerase Required for Sister Chromatid Cohesion Zhenghe Wang, Irene B. Castaño,* Alejandro De Las Peñas,* Carrie Adams, Michael F. Christman Establishment of cohesion between sister chromatids is coupled to replication fork passage through an unknown mechanism. (bio.net)
  • Identification of Xenopus SMC protein complexes required for sister chromatid cohesion. (semanticscholar.org)
  • Pds5p and the cohesin complex are required for sister chromatid cohesion and localize to the same chromosomal loci over the same cell cycle window. (rupress.org)
  • Calpain 2 is required for sister chromatid cohesion. (inserm.fr)
  • Ctf7 is also required for sister chromatid cohesion during repair of DNA double strand breaks. (biomedcentral.com)
  • We show that UBL5 is required for sister chromatid cohesion maintenance in human cells. (embopress.org)
  • An exception is towards the end of meiosis, after crossing over has occurred, because sections of each sister chromatid may have been exchanged with corresponding sections of the homologous chromatids with which they are paired during meiosis. (wikipedia.org)
  • Studies with the budding yeast Saccharomyces cerevisiae indicate that inter-sister recombination occurs frequently during meiosis, and up to one-third of all recombination events occur between sister chromatids. (wikipedia.org)
  • In chromosomal crossovers, non-sister (homologous) chromatids form chiasmata to exchange genetic material during the prophase I of meiosis (See Homologous recombination). (wikipedia.org)
  • During meiosis, homologous sets of sister chromatids get together to form the tetrad , where they cross over . (everything2.com)
  • The nonrandom occurrence of crossovers along a single strand during meiosis can be caused by either chromatid interference, crossover interference or both. (genetics.org)
  • Sister chromatid cohesion and recombination in meiosis. (nih.gov)
  • In Drosophila males and females mutant for the ord gene, sister chromatids prematurely disjoin in meiosis. (genetics.org)
  • Strong ord alleles result in chromosome nondisjunction in meiosis I that appears to be the consequence of precocious separation of the sister chromatids followed by their random segregation. (genetics.org)
  • Thus, there are 92 chromatids in each cell (4xN) which occurs during anaphase 2 of meiosis . (bionity.com)
  • The term chromatid was proposed by McClung (1900) for each of the four threads making up a chromosome -pair during meiosis . (bionity.com)
  • But in meiosis , crossing over (exchanges) take place between two of the non-sister chromatids. (wikipedia.org)
  • The process in which sister chromatids are physically detached from each other during meiosis. (yeastgenome.org)
  • Crossing over between non-sister chromatids of homologous chromosomes occurs in meiosis during prophase I. (reference.com)
  • Before prophase I of meiosis, the oogonium contains diploid chromosomes but tetraploid DNA, with each chromosome being made of two sister chromatids. (reference.com)
  • In the early stages of meiosis, the process of replication copies the DNA to produce chromosomes with two sister chromatids (see Figure 1 ). (elifesciences.org)
  • During the first round of segregation, called meiosis I, spindle microtubules attach themselves to the chromosomes with the help of large protein complexes called kinetochores that are found on each chromatid (see Figure 1 ). (elifesciences.org)
  • In meiosis II essentially the same cast of players (that is, spindle microtubules and kinetochores), segregate the sister chromatids to produce a total of four cells. (elifesciences.org)
  • Third, protein rings made up of cohesins are thought to encircle the two sister chromatids: this creates cohesion between the chromatids and prevents them from separating prematurely during meiosis I. When the two homologous chromosomes are attached to opposite spindle poles during metaphase I (a stage after prophase), the spindle forces are resisted by the physical linkages and the cohesion between sister chromatids. (elifesciences.org)
  • Together these three mechanisms ensure that homologous chromosomes are segregated in meiosis I, while sister chromatids remain together. (elifesciences.org)
  • The proper segregation of homologs at meiosis I and sister chromatids during meiosis II is essential for the survival of the offspring. (tennessee.edu)
  • Stromalin in Meiosis (SNM), a member of the SCC3/STAG cohesion family, is required for homolog pairing in male Drosophila but not for meiotic sister chromatid cohesin. (tennessee.edu)
  • Mutations in sun cause premature sister chromatid segregation (PSCS) and nondisjunction (NDJ) of both homologous and sister chromatids, and also disrupt normal recombination and synapsis in female meiosis. (tennessee.edu)
  • The four chromatids in each bivalent exhibit random segregation at meiosis I. We found that centromeric cohesion is lost in the absence of SUN during mid-prophase (S4). (tennessee.edu)
  • Sister chromatid cohesion is essential to maintain stable connections between homologues and sister chromatids during meiosis and to establish correct centromere orientation patterns on the meiosis I and II spindles.However, the meiotic cohesion apparatus in Drosophila melanogaster remains largely uncharacterized.We describe a novel protein, sisters on the loose (SOLO), which is essential for meiotic cohesion in Drosophila. (nih.gov)
  • Sister chromatid cohesion is essential to maintain stable connections between homologues and sister chromatids during meiosis and to establish correct centromere orientation patterns on the meiosis I and II spindles. (nih.gov)
  • In solo mutants, sister centromeres separate before prometaphase I, disrupting meiosis I centromere orientation and causing nondisjunction of both homologous and sister chromatids. (nih.gov)
  • The solo mutant phenotypes and the localization patterns of SOLO and SMC1 indicate that they function together to maintain sister chromatid cohesion in Drosophila meiosis. (nih.gov)
  • AtCTF7 -RNAi plants displayed chromosome fragmentation and loss of sister chromatid cohesion during meiosis. (biomedcentral.com)
  • During meiosis, sister chromatids are separated and move toward opposite ends of the cell as the centromeres that hold them separate. (securedigitalinfo.com)
  • During meiosis, non-soster chromatids overlap to form chiasmata. (anydifferencebetween.com)
  • BACKGROUND: Follicular fluid meiosis-activating sterol (FF-MAS) protects young oocytes from precocious chromatid separation (predivision). (uni-bielefeld.de)
  • Influence of follicular fluid meiosis-activating sterol on aneuploidy rate and precocious chromatid segregation in aged mouse oocytes", HUMAN REPRODUCTION , vol. 22, 2007, pp. 815-828. (uni-bielefeld.de)
  • Sister chromatid cohesion is intimately linked to other aspects of chromosome behaviour and metabolism, in particular chromosome condensation, recombination and segregation. (nih.gov)
  • These include the individualization and compaction of the two copies of replicated chromosomes (the sister chromatids) and their subsequent segregation to the daughter cells. (nih.gov)
  • Cohesin is required for holding sister chromatids together whereas condensin, together with topoisomerase II, has an important role in organizing individual axes of sister chromatids prior to their segregation during anaphase. (nih.gov)
  • Sister chromatid cohesion is essential for chromosome segregation and is mediated by cohesin bound to DNA. (nih.gov)
  • Establish role of Pim-1 on non-random chromatid segregation and correlate with daughter cell fate determination in cardiac progenitor cells. (ahajournals.org)
  • Density measurements showed that 4.6% of CPCs outside the 95% confidence interval for equal BrdU intensity between daughter nuclei indicating non-random segregation of BrdU labeled chromatids. (ahajournals.org)
  • CPCs non-randomly segregate chromatids as demonstrated by selective segregation of BrdU labeled chromatids which is twofold increased in cells overexpressing Pim-1 kinase. (ahajournals.org)
  • The relationship of non-random chromatid segregation to identity of stem cells fate remains to be determined. (ahajournals.org)
  • This sister chromatid cohesion is essential for accurate chromosome segregation during cell division. (findaphd.com)
  • PDS5B is a sister chromatid cohesion protein that is crucial for faithful segregation of duplicated chromosomes in lower organisms. (biologists.org)
  • Sister chromatid cohesion, the linkage of sister chromatids from S phase until onset of anaphase, is important for accurate chromosome segregation during cell division and is mediated by a highly conserved multi-protein complex, called cohesin. (biologists.org)
  • The selective chromatid segregation model has been proposed as a mechanism for the asymmetric cell division that initiates a cascade of gene regulation events in offspring cells to develop brain laterality in embryogenesis. (omicsonline.org)
  • The translocations we propose might cause random segregation of its sister chromatids to explain the result of 50% penetrance. (omicsonline.org)
  • We discovered a novel role for Bre1, Lge1 and H2Bub1 in chromosome segregation and sister chromatid cohesion. (elifesciences.org)
  • The protein complex cohesin is a major component of SCC and links sister chromatids together from the time of their replication until their segregation. (tennessee.edu)
  • The cleavage of RAD21 subunit of centromeric cohesin by ESPL1 (separin i.e. separase) promotes dissociation of cohesin complexes from centromeric chromatin at the onset of anaphase, allowing for sister chromatid separation and segregation of replicated chromosomes to daughter cells (Waizenegger et al. (reactome.org)
  • Recent papers in The EMBO Journal and EMBO Reports reveal that expression of sororin, a critical regulator that stabilizes cohesin rings in sister chromatids, is exquisitely sensitive to defects in the splicing machinery, thus explaining the striking link between spliceosome function and chromosome segregation. (embopress.org)
  • The cohesin rings that remain at the centromeric regions are later proteolytically cleaved leading to the ordered segregation of sister chromatids during the metaphase‐to‐anaphase transition (Fig 1 ). (embopress.org)
  • Proper chromosome segregation during cell division requires that sister chromatids produced by DNA replication are held together until their controlled separation at anaphase. (biomedcentral.com)
  • Loss of cohesion between sister chromatids triggers their segregation during anaphase. (securedigitalinfo.com)
  • 3. "Chromosomes, Chromatids and Chromatin" www.khanacademy.org. (wikipedia.org)
  • Each of the two daughter chromatids contains the same DNA and chromatin protein as its original chromosome. (wikipedia.org)
  • The division of the cell into two results in each daughter cell with a set of chromatids that eventually revert into the thin, less distinct chromatin , each containing a single strand of DNA . (biology-online.org)
  • 1-Chromatin, chromosomes, and chromatid all consist of DNA AND some sort of proteins? (protocol-online.org)
  • 2-Is the following statement accurate: ALL types/forms of chromatin material and chromatids consist of chromosomes BUT not all types of chromosomes are chromatin or chromatids? (protocol-online.org)
  • We found that in budding yeast, the head domain of the Smc3p subunit of cohesin is acetylated by the Eco1p acetyltransferase at two evolutionarily conserved residues, promoting the chromatin-bound cohesin to tether sister chromatids. (sciencemag.org)
  • At metaphase-anaphase transition, this protein is cleaved by ESP1 and dissociates from chromatin, allowing sister chromatids to segregate. (uniprot.org)
  • These findings emphasise that chromosomal location is important for defining the replication timing of genes and show that retarded sister-chromatid resolution is a novel feature of inactive chromatin. (ox.ac.uk)
  • Cytological analysis in males confirmed that precocious disjunction of the sister chromatids occurs in prometaphase I. This is in contrast to Drosophila mei-S332 mutants, in which precocious sister-chromatid separation also occurs, but not until late in anaphase I. All three of the new female fertile ord alleles reduce recombination, suggesting they affect homolog association as well as sister-chromatid cohesion. (genetics.org)
  • Sister chromatid cohesion (the binding together of the two identical copies of each chromosome that are formed during replication) helps to ensure that chromosomes are accurately segregated during the anaphase of the cell cycle. (eurekalert.org)
  • Homologous chromosomes then segregate during anaphase I. During metaphase II, sister chromatids attach to opposite spindle poles and separate in anaphase II, creating meiotic products with half the set of chromosomes. (elifesciences.org)
  • At the metaphase to anaphase transition, sister chromatid cohesion is dissolved synchronously on all chromosomes and sisters segregate to opposite poles via microtubule-dependent movement. (rupress.org)
  • Like in that form it was inactive and the whole purpose of the anaphase promoting complex was to destroy the securin, liberate the Separase and then the Separase went off and did something magical to the chromosomes and maybe the spindle apparatus that would cause the sister chromatids to be pulled to opposite poles. (cshl.edu)
  • B. sister chromatids are separated during anaphase II to become the chromosomes of the daughter cells. (securedigitalinfo.com)
  • Recent work has identified both a cohesin complex that holds sisters toge For the best answers, search on this site https://shorturl.im/avftu Anaphase I (not anaphase II because during this phase, sister chromatids The proteins that bind the sister chromatids are split so they become seperated. (securedigitalinfo.com)
  • In anaphase A, the kinetochore microtubules shorten, pulling the sister chromatids apart. (securedigitalinfo.com)
  • sister chromatids separate during anaphase. (securedigitalinfo.com)
  • The proteins that bind the sister chromatids It during the anaphase that sister chromatids separated. (securedigitalinfo.com)
  • During metaphase, these chromatids align on the metaphase plate and in the anaphase stage, they are separated and incorporated into different daughter cells. (anydifferencebetween.com)
  • A sister chromatid refers to the identical copies (chromatids) formed by the replication of a chromosome, with both copies joined together by a common centromere. (wikipedia.org)
  • In cell division, after replication of the cell's chromosomes, the two copies, called sister chromatids, must be kept together to ensure that each daughter cell receives an equal complement of chromosomes. (esrf.eu)
  • This suggests that TRFs are a key link in the coordination between DNA replication and sister chromatid cohesion. (bio.net)
  • Since this replication is meant to result in identical cells, non-sister chromatids are never formed, and crossing over cannot occur. (reference.com)
  • A sister chromatid refers tae the identical copies ( chromatids ) formed bi the replication o a chromosome , wi baith copies jynt thegither bi a common centromere . (wikipedia.org)
  • Ctf7p is essential for sister chromatid cohesion and links mitotic chromosome structure to the DNA replication machinery. (semanticscholar.org)
  • The cohesin complex is required for the cohesion of sister chromatids after DNA replication. (uniprot.org)
  • In this project, we will use a biochemical approach to study molecular mechanisms of how sister chromatid cohesion is established during DNA replication. (findaphd.com)
  • During DNA replication, an active process termed cohesion establishment turns cohesin into physical linkages between sister chromatids. (findaphd.com)
  • Sister chromatid exchange (SCE) is known to result from reciprocal DNA interchange in homologous loci of sister chromatids in the replication process and it occurs spontaneously at certain rates in all cells. (bmj.com)
  • There is strong evolutionary pressure resulting in semi-conservative replication as indicated by extremely low level of sister chromatid exchange errors(SCE). (jbsdonline.com)
  • These findings demonstrate that Mus81/Eme1 is the dedicated endonuclease that resolves sister chromatid recombination intermediates during the repair of broken replication forks. (embopress.org)
  • It is generally accepted that a one‐ended DSB uses the intact sister chromatid for repair, as it is the closer homologous sequence and may simultaneously repair the broken end and restore the fork structure, allowing replisome reassembly and replication to restart. (embopress.org)
  • The product of HR between sister chromatids is genetically invisible, because DNA replication by definition produces two identical chromosomes. (embopress.org)
  • After replication, the duplicated chromatids (sister chromatids) are associated along their entire length. (rupress.org)
  • Patient-derived cell lines exhibit sensitivity to topoisomerase and PARP inhibitors, defective sister chromatid cohesion and reduced DNA replication fork speed. (eur.nl)
  • SCC is mediated by the cohesion ring (Losada, 2014 ), a four‐subunit complex that entraps DNA fibers, topologically preventing the separation of sister chromatids after DNA replication (Fig 1 ). (embopress.org)
  • After replication (S‐phase), the cohesin ring maintains sister chromatids together. (embopress.org)
  • Heritable gene silencing in lymphocytes delays chromatid resolution without affecting the timing of DNA replication. (ox.ac.uk)
  • Meiotic sister chromatid recombination. (nih.gov)
  • Sister chromatid exchange (SCE) is an error-free recombination mechanism, defined as a symmetrical exchange between portions of apparently homologous sister chromatids ( 4 ). (spandidos-publications.com)
  • These results indicate that Rad51C plays a pivotal role in determining the "choice" between short- and long-tract gene conversion and in suppressing gene amplifications associated with sister chromatid recombination. (asm.org)
  • DSB formed during the S or G 2 phase of the cell cycle may be repaired preferentially by homologous recombination (HR) between sister chromatids (sister chromatid recombination [SCR]) ( 37 ). (asm.org)
  • DNA polymerase stalling, sister chromatid recombination and the BRCA genes. (ebscohost.com)
  • We suggest that endogenous crossover recombination mediates cooperative pairing interactions between all four chromatids of a meiotic bivalent. (elsevier.com)
  • Cohesion between sister chromatids is provided by protein complexes, of which some components are conserved across the kingdoms and between the mitotic and meiotic cell cycles. (nih.gov)
  • The protein complex cohesin keeps the sister chromatids together, but how it interacts with the DNA was unknown. (esrf.eu)
  • Sister chromatid cohesion is mediated by a multi-subunit protein complex called cohesin. (eurekalert.org)
  • Using reversible inhibitors of DNA-PK (DNA-dependent protein kinase), another kinase involved in responding to DNA damage, and ATM, we showed that these two kinases acted through distinct DNA repair mechanisms: ATM resolved DNA damage through a mechanism involving sister chromatid exchange (SCE), whereas DNA-PK acted through nonhomologous end joining. (sciencemag.org)
  • 29 coke oven workers and a standardised control group were investigated for frequencies of DNA single strand breakage, DNA protein cross links (alkaline filter elution assay), sister chromatid exchange, and DNA adducts ({sup}32{end}P postlabeling assay) in lymphocytes. (ebscohost.com)
  • Below are the list of possible Sister chromatid cohesion 1 protein products. (mybiosource.com)
  • Also known as Sister chromatid cohesion 1 protein 1 (Protein DETERMINATE INFERTILE 1) (SCC1 homolog 1). (mybiosource.com)
  • Its absence leads to aberrant Sororin mRNA intron retention, low Sororin protein levels, and thus defective sister chromatid cohesion in human cells. (embopress.org)
  • Knockdown of UBL5 or other splicing factors leads to missplicing of Sororin transcripts and, thus, a decrease in Sororin protein levels that causes premature sister chromatid separation. (embopress.org)
  • The "molecular glue" that links sister DNA molecules is called cohesin, a tripartite ring-like protein complex composed of two Structural Maintenance of Chromosome proteins (Smc1 and Smc3) bridged by a kleisin subunit Rad21/Scc1, that together prevent precocious sister chromatid separation. (unl.pt)
  • The DNA helicase domain of DDX11 is essential for sister chromatid cohesion and resistance to G4 stabilizers. (eur.nl)
  • To study the role of Rad51C in vivo in mammalian cells, we analyzed short-tract and long-tract gene conversion between sister chromatids in hamster Rad51C −/− CL-V4B cells in response to a site-specific chromosomal double-strand break. (asm.org)
  • Measurement of chromosomal aberrations, sister chromatid exchange, hprt mutations, and DNA adducts in peripheral lymphocytes of human populations at increased risk for cancer Morris, M. (ebscohost.com)
  • McFee, A.F., and M.N. Sherrill (1981) Mitotic response and sister chromatid exchanges in lymphocytes cultured in sera from different sources. (springer.com)
  • We report that HDACI treatment induces premature sister chromatid separation in cells in which the mitotic spindle assembly checkpoint (SAC) has already been activated. (aacrjournals.org)
  • Thus, Capn2 may play a role in fundamental mitotic functions, such as the maintenance of sister chromatid cohesion. (inserm.fr)
  • An important gene associated with Premature Chromatid Separation Trait is BUB1B (BUB1 Mitotic Checkpoint Serine/Threonine Kinase B). Affiliated tissues include cervix , and related phenotype is premature chromatid separation . (malacards.org)
  • Carrano, A.V., J.L. Minkler, D.G. Stetka, and D.H. Moore (1980) Variation in the baseline sister chromatid exchange frequency in human lymphocytes. (springer.com)
  • Morgan, W.F., and P.E. Crossen (1981) Factors influencing sister-chromatid exchange rate in cultured human lymphocytes. (springer.com)
  • Ghosh, P.K., and R. Nand (1979) Reduced frequency of sister chromatid exchanges in human lymphocytes cultured in autologous serum. (springer.com)
  • Abdel-Fadil, M.R., C.G. Palmer, and N. Heerema (1982) Effect of temperature variation on sister-chromatid exchange and cell-cycle duration in cultured human lymphocytes. (springer.com)
  • Inhabitants of the Hohhot Region in Inner Mongolia who drink high-fluoride (4-15 mg/L) water were compared for their micronucleus (MN) rate and sister chromatid exchange (SCE) frequency in their peripheral blood lymphocytes. (fluoridealert.org)
  • Sister chromatid exchange analysis in lymphocytes of workers exposed to hexavalent chromium. (bmj.com)
  • To investigate the usefulness of sister chromatid exchange (SCE) analysis in lymphocytes as an indicator for mutagenic effects after in vivo exposure to hexavalent chromium (Cr), SCE frequency was analysed in lymphocytes of 44 Cr platers occupationally exposed to hexavalent Cr and 47 controls. (bmj.com)
  • Blood lymphocytes were examined to determine the frequency of sister chromatid exchange (SCE). (fluoridealert.org)
  • SUMMARY: Peripheral blood lymphocytes of residents of three villages and one nearby township in South Gujarat with fluoride concentrations in the drinking water of 1.56 - 3.46 and 0.6 - 0.8 ppm, respectively, were examined for their frequency of sister chromatid exchanges (SCE) and chromosome aberra-tions. (slweb.org)
  • Gossypol induces DNA strand breaks in human fibroblasts and sister chromatid exchanges in human lymphocytes in vitro. (bmj.com)
  • Instead, the heritable silencing of some genes (Rag-1, TdT, CD8alpha and lambda5) and their spatial recruitment to heterochromatin domains within the nucleus of lymphocytes resulted in a markedly delayed resolution of sister chromatids into doublet signals discernable by 3D fluorescence in situ hybridization (FISH). (ox.ac.uk)
  • METHODS Anti-clastogenic and anti-genotoxic activities of Ulva rigida crude extracts (URE) were studied using chromosome aberration (CA), sister chromatid exchange (SCE), and micronuclei (MN) tests in human lymphocytes cultured in vitro. (semanticscholar.org)
  • In the September 1st issue of G&D, Drs. Rudra Dubey and Marc Gartenberg (UMDNJ) reveal a surprising new role for tDNAs and RNA polymerase III-associated proteins in sister chromatid cohesion. (eurekalert.org)
  • We had meanwhile identified many of the proteins that were directly involved in holding sister chromatids together. (cshl.edu)
  • The proteins that bind the sister chromatids are split so they become seperated. (securedigitalinfo.com)
  • The two strands are each a chromatid . (everything2.com)
  • Each chromosome is comprised of two strands joined by a kinetochore and either of the two strands is called a chromatid . (biology-online.org)
  • 5-Chromatid refers to a SINGLE chromosome/DNA strand in the complex of the two DNA strands/chromosomes which are attached? (protocol-online.org)
  • Non-sister chromatids containing newly synthesized DNA and 'old' DNA strands are non-randomly partitioned between mother and daughter cells. (ahajournals.org)
  • The ord gene product may prevent premature sister-chromatid separation by promoting cohesion of the sister chromatids in a structural or regulatory manner. (genetics.org)
  • Low Capn2 levels induce chromosome alignment defects, the loss of histone H3 threonine 3 phosphorylation at centromeres, and premature sister chromatid separation. (inserm.fr)
  • Pharmacological or genetic inactivation of the GSK3-FBXW7-JunB axis induced accumulation of JunB in G2/M and entailed transcriptional repression of the DNA helicase DDX11, leading to premature sister chromatid separation. (cnrs.fr)
  • Premature Chromatid Separation Trait, also known as pcs , is related to mosaic variegated aneuploidy syndrome 1 and mosaic variegated aneuploidy syndrome . (malacards.org)
  • Cohesin holds the replicated chromosomes (sister chromatids) together to mediate sister chromatid cohesion. (sciencemag.org)
  • These results indicate that Pds5p cooperates with the cohesin complex to mediate sister chromatid cohesion, but that Pds5p and the cohesin complex serve distinct roles in cohesion. (rupress.org)
  • To study the function of Ctf7 in plants and to determine its role in sister chromatid cohesion, we constructed a conditional allele of AtCTF7 in Arabidopsis using an inducible RNA interference (RNAi) strategy, so as to avoid the embryo lethality caused by mutations in AtCTF7 . (biomedcentral.com)
  • A: Sister chromatids are a pair of synthesized daughter chromatids generated when a single chromosome is duplicated into two copies of the parent chromosome. (securedigitalinfo.com)
  • We are excited by the prospect that these same elements govern yet another layer of chromosome architecture through the establishment of sister chromatid cohesion," explains Dr. Gartenberg. (eurekalert.org)
  • Eco1-dependent cohesin acetylation during establishment of sister chromatid cohesion. (semanticscholar.org)
  • Mazrimas, J.A., and D.G. Stetka (1978) Direct evidence for the role of incorporated BUdR in the induction of sister chromatid exchanges. (springer.com)
  • The induction of sister chromatid exchange (SCE) has been proposed as a predictive test for the identification of mutagens/carci-nogens. (springer.com)
  • The induction of sister chromatid exchanges (SCEs) by triethylenemelamine (51183) (TEM) was studied in mice and hamsters. (cdc.gov)
  • Apparent enhanced response to the induction of sister chromatid exchange by mitomycin C in myotonic dystrophy. (bmj.com)
  • This paper presents the results of testing gossypol acetate for the possible induction of sister chromatid exchanges (SCEs) in mouse spermatogonial cells in vivo following a single intraperitoneal injection of BudR adsorbed on charcoal. (springer.com)
  • Schempp, W., and W. Krone (1979) Deficiency of arginine and lysine causes increase in the frequency of sister chromatid exchanges. (springer.com)
  • The frequency of sister chromatid exchanges among chromosomes correlates with chromosome length. (sciencemag.org)
  • Sister chromatid exchange (SCE) frequency. (fluoridealert.org)
  • Sister chromatid exchange (SCE) frequency is widely used as an indicator of spontaneous chromosome instability. (spandidos-publications.com)
  • The effect of co-culturing varying concentrations of pig and human red blood cells (RBCs) on the baseline frequency of sister chromatid exchanges (SCEs) and cell-cycle progression in pig plasma (PLCs) and whole blood leukocyte cultures (WBCs) was studied. (scielo.br)
  • OBJECTIVE This study investigated whether any genomic change occurs in DNA level in ankylosing spondylitis (AS) by measuring sister chromatid exchange (SCE) frequency. (bmj.com)
  • The relationship between the 'spontaneous' frequency of sister-chromatid exchanges (SCE) and tumorigenicity was studied in a series of hybrids between a C57BL melanoma cell line and diploid cells, but no correlation was found between the 2 variables. (biologists.org)
  • Thus, Pds5p, like the cohesin complex members, is a component of the molecular glue that mediates sister chromatid cohesion. (rupress.org)
  • The approaches described here take advantage of a system in Drosophila melanogaster where the Tobacco Etch Virus (TEV) protease can cleave the Rad21 subunit of cohesin leading to precocious sister chromatid separation. (unl.pt)
  • Stem cells are presumed to non-randomly segregate chromatids to determine cell fate of daughter cells, although experimental evidence is lacking. (ahajournals.org)
  • The cohesin complex apparently forms a large proteinaceous ring within which sister chromatids can be trapped. (uniprot.org)
  • The cohesin complex comprises only part of the molecular glue responsible for sister chromatid cohesion. (rupress.org)
  • Sister chromatids are preferred over homologs as substrates for recombinational repair in Saccharomyces cerevisiae" (Free full text). (wikipedia.org)
  • Compare sister chromatids to homologous chromosomes, which are the two different copies of a chromosome that diploid organisms (like humans) inherit, one from each parent. (wikipedia.org)
  • The two identical copies-each forming one half of the replicated chromosome-are called chromatids. (wikipedia.org)
  • Sometimes sister chromatids do not separate during cell division, leading to a situation known as nondisjunction where one daughter cell lacks the chromosome while the other gets both copies of it. (wikipedia.org)
  • Sister chromatids are exact copies of each other (save for the rare mutation during the copy process). (securedigitalinfo.com)
  • Chromatid refers to one of the copies of the chromosomes. (anydifferencebetween.com)
  • Kato, H. (1980) Temperature-dependence of sister chromatid exchange: An implication for its mechanism. (springer.com)
  • Other tumors use an alternative mechanism of telomere lengthening (ALT), characterized by high frequencies of telomeric sister chromatid exchanges (T-SCEs). (nature.com)
  • However, the mechanism of spatial separation of the replication's products, particularly the problem of avoiding mixing between sister chromatids, remains unexplained. (jbsdonline.com)
  • Insights into the timing, distribution, and mechanism of sister chromatid cohesion have been provided through studies of mammalian and yeast cells. (rupress.org)
  • Formation of sister chromatid exchanges (SCE) is a mechanism of repair or bypass of DNA damage during S phase. (ebscohost.com)
  • When the level of MAU-2 was low, less cohesin was loaded onto the chromosomes, and sister chromatids prematurely separated, just as in yeast. (rxpgnews.com)
  • Inside the cell nucleus, cohesin localizes to centromeres (the point of attachment of sister chromatids) as well as heterochromatin (condensed and genetically inactive regions of DNA). (eurekalert.org)
  • 10-There are two centromeres and two kinetechores for sister chromatids. (protocol-online.org)
  • They are called sister chromatids so long as they are joined by the centromeres. (academic.ru)
  • Enhancing effect of tetrandrine on sister-chromatid exchanges induced by mitomycin C and cigarette-smoke condensate in mammalian cells. (cdc.gov)
  • Sister-chromatid exchanges induced by triethylenemelamine: in vivo and in vivo/in vitro studies in mouse and Chinese hamster bone and spleen cells. (cdc.gov)
  • Sister chromatid cohesion is essential for the correct distribution of genetic information between daughter cells and the repair of damaged chromosomes. (wikipedia.org)
  • Although having the same genetic mass as the individual chromatids that made up its parent, the daughter "molecules" are called chromosomes in a similar way that one child of a pair of twins is not referred to as a single twin. (wikipedia.org)
  • Sister chromatid exchange (SCE) is the exchange of genetic information between two sister chromatids. (wikipedia.org)
  • During the DNA repair process, Sister chromatid exchange takes place which is the exchange of genetic material. (anydifferencebetween.com)