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  • genes
  • For much of the 20th century, genes were considered to be stable entities arranged in an orderly linear pattern on chromosomes, like beads on a string ( 1 ). (pnas.org)
  • She also found that depending on where they inserted into a chromosome these mobile elements could reversibly alter the expression of other genes. (pnas.org)
  • They are often susceptible to spontaneous breakage during replication, frequently affecting neighboring genes. (wikipedia.org)
  • Evolution of Genes to Ensure Correct Chromosome Pairing There have been rare events in which genes that ensure proper chromosome pairing have evolved shortly after polyploidization. (wikipedia.org)
  • At the MRC HGU, Edinburgh (1990 - 2002), and subsequently at the Wellome Trust Centre for Cell Biology, University of Edinburgh (2002-present), he discovered that genes are silenced when placed within fission yeast centromeres and telomeres, and then utilised this gene silencing to gain fundamental insights into the processes of chromosome segregation, and heterochromatin and kinetochore CENP-A chromatin establishment and maintenance. (wikipedia.org)
  • The next stage took place after the development of genetics in the early 20th century, when it was appreciated that the set of chromosomes (the karyotype) was the carrier of the genes. (wikipedia.org)
  • In the 1940s and early 1950s, experiments pointed to DNA as the portion of chromosomes (and perhaps other nucleoproteins) that held genes. (wikipedia.org)
  • anaphase
  • We show that a single, short exposure of cultured mammalian epithelial cells to live pks + E. coli at low infectious doses induced a transient DNA damage response followed by cell division with signs of incomplete DNA repair, leading to anaphase bridges and chromosome aberrations. (pnas.org)
  • locus
  • For example, breakage at or near the FRA11b locus has been implicated in Jacobsen syndrome, which is characterized by loss of part of the long arm of chromosome 11 accompanied by mild mental retardation. (wikipedia.org)
  • paternal
  • Deletions of paternal origin (father) are larger than the deletions deriving from the maternal (mother) chromosome. (wikipedia.org)
  • There do not seem to be differences in the clinical manifestations (the symptoms or observable conditions which are seen as a result of 1p36) based on whether the deletion is on the paternal or maternal chromosome. (wikipedia.org)
  • 70% of patients present a 5-7-Mb de novo deletion in the proximal region of the paternal chromosome 15. (wikipedia.org)
  • mitosis
  • Joe Hin Tjio working in Albert Levan's lab was responsible for finding the approach: Using cells in culture Pre-treating cells in a hypotonic solution, which swells them and spreads the chromosomes Arresting mitosis in metaphase by a solution of colchicine Squashing the preparation on the slide forcing the chromosomes into a single plane Cutting up a photomicrograph and arranging the result into an indisputable karyogram. (wikipedia.org)
  • structural
  • Structural maintenance of chromosomes protein 6 is a protein that in humans is encoded by the SMC6 gene. (wikipedia.org)
  • Genome shock can be defined as a stage in which the genome experiences massive reorganization and structural changes to deal with the external stress (X-ray damage, chromosome duplication, etc.) imposed upon the genome (3). (wikipedia.org)
  • In all of these examples the derivative populations grow adjacent to the parental species, which they resemble closely in morphology, but from which they are reproductively isolated because of multiple structural differences in their chromosomes. (wikipedia.org)
  • phenotypic
  • Levitsky seems to have been the first to define the karyotype as the phenotypic appearance of the somatic chromosomes, in contrast to their genic contents. (wikipedia.org)
  • segments
  • The intervening DNA between the V and D segments is ligated to form a circular DNA molecule that is lost from the chromosome. (wikipedia.org)
  • The exposed 3' termini are subject to deletion and addition of nucleotides by a variety of exonucleases and DNA polymerases, before the V and D segments are ligated to restore the integrity of the chromosome. (wikipedia.org)
  • genomic
  • Techniques used include karyotyping, analysis of G-banded chromosomes, other cytogenetic banding techniques, as well as molecular cytogenetics such as fluorescent in situ hybridization (FISH) and comparative genomic hybridization (CGH). (wikipedia.org)
  • mechanisms
  • These results reaffirm our previous findings that oxidative stress-induced apoptosis could be one of the potential mechanisms underlying chromosome breakages in nasopharyngeal epithelial cells. (springer.com)
  • incidence
  • The term 'incidence' of Thrombocytopenia -- chromosome breakage refers to the annual diagnosis rate, or the number of new cases of Thrombocytopenia -- chromosome breakage diagnosed each year. (rightdiagnosis.com)
  • Cells deficient in Artemis are more sensitive than normal cells to X‑rays and to chemical agents that induce double-strand breaks (DSBs), and they show a higher incidence of chromosome breaks following irradiation. (wikipedia.org)
  • behaviour
  • Her Ph.D. thesis was The correlation between chromosome behaviour and susceptibility to mammary gland cancer in mice (1938), for which she won the Governor General's Academic Medal for graduate work in science. (wikipedia.org)
  • sequence
  • We also acknowledge Genome Canada for support of EST library construction and sequencing through the Protist EST Project and grant RR-009231 to EO from the National Institutes of Health (the National Center for Research Resources) which supported the RAPD and Cbs work and an EO subcontract to NSF grant MCB-0132675 which supported sequence analyses related to number of chromosomes and their copy number. (blogspot.com)
  • structures
  • The CGG and AT-rich repeats characteristic of RFSs can form hairpins and other non-B DNA structures that block replication forks and can result in breakage. (wikipedia.org)
  • genome
  • We report here the shotgun sequencing, assembly, and analysis of the MAC genome of T. thermophila , which is approximately 104 Mb in length and composed of approximately 225 chromosomes. (blogspot.com)
  • formation
  • Patient cells exhibited deficiency in BRCA1 and RAD51 localization to DNA-damage sites, combined with radial chromosome formation and hypersensitivity to ICL-inducing agents. (aacrjournals.org)
  • The formation of multivalents results in unequal division of the chromosomes and lead to daughter cells lacking one or few chromosomes. (wikipedia.org)
  • rare
  • Impairments in chromosome maintenance are linked to rare chromosome breakage disorders. (jci.org)
  • Rare fragile sites (RFSs) are classified into two sub-groups based on the compounds that elicit breakage: folate-sensitive groups (for examples, see ), and nonfolate-sensitive groups, which are induced by bromodeoxyuridine (BrdU) or distamycin A, an antibiotic that preferentially binds to AT-pairs of DNA. (wikipedia.org)
  • structure
  • Common fragile sites are considered part of normal chromosome structure and are present in all (or nearly all) individuals in a population. (wikipedia.org)
  • As a geneticist, Howard already recognized the importance of DNA, and although the double helix structure would not be discovered for a few more years, "the idea that chromosomes are made of DNA was generally agreed on. (wikipedia.org)
  • exchange
  • At the level of the chromosomes, the rate of sister chromatid exchange in Bloom's syndrome is approximately 10 fold higher than normal and quadriradial figures, which are the cytologic manifestations of crossing-over between homologous chromosome, are highly elevated. (wikipedia.org)
  • cell
  • This work resulted from following the fate of fission yeast (Schizosaccharomyces pombe) telomeres after introdroducing fission yeast chromosomes into mouse cell in collaoration with Peter Fantes. (wikipedia.org)
  • Investigation into the human karyotype took many years to settle the most basic question: how many chromosomes does a normal diploid human cell contain? (wikipedia.org)
  • important
  • the BLM gene encodes a RecQ DNA helicase important for DNA repair, defects of which give rise to this "chromosome breakage syndrome. (bmj.com)
  • The repeated occurrence of the same pattern of differentiation in Clarkia suggests that a rapid reorganization of chromosomes has been an important mode of evolution in the genus. (wikipedia.org)