Dielectrophoretic manipulation of human chromosomes in microfluidic channels: extracting chromosome dielectric properties

DEFF Research Database (Denmark)

Clausen, Casper Hyttel; Dimaki, Maria; Buckley, Sonia

2011-01-01

An investigation of the dielectric properties of polyamine buffer prepared human chromosomes is presented in this paper. Chromosomes prepared in this buffer are only a few micrometers in size and shaped roughly like spherical discs. Dielectrophoresis was therefore chosen as the method...... of manipulation combined with a custom designed microfluidic system containing the required electrodes for dielectrophoresis experiments. Our results show that although this system is presently not able to distinguish between the different chromosomes, it can provide average data for the dielectric properties...... of human chromosomes in polyamine buffer. These can then be used to optimize system designs for further characterization and even sorting. The experimental data from the dielectrophoretic manipulation were combined with theoretical calculations to extract a range of values for the permittivity...

Centromere Destiny in Dicentric Chromosomes: New Insights from the Evolution of Human Chromosome 2 Ancestral Centromeric Region.

Science.gov (United States)

Chiatante, Giorgia; Giannuzzi, Giuliana; Calabrese, Francesco Maria; Eichler, Evan E; Ventura, Mario

2017-07-01

Dicentric chromosomes are products of genomic rearrangements that place two centromeres on the same chromosome. Due to the presence of two primary constrictions, they are inherently unstable and overcome their instability by epigenetically inactivating and/or deleting one of the two centromeres, thus resulting in functionally monocentric chromosomes that segregate normally during cell division. Our understanding to date of dicentric chromosome formation, behavior and fate has been largely inferred from observational studies in plants and humans as well as artificially produced de novo dicentrics in yeast and in human cells. We investigate the most recent product of a chromosome fusion event fixed in the human lineage, human chromosome 2, whose stability was acquired by the suppression of one centromere, resulting in a unique difference in chromosome number between humans (46 chromosomes) and our most closely related ape relatives (48 chromosomes). Using molecular cytogenetics, sequencing, and comparative sequence data, we deeply characterize the relicts of the chromosome 2q ancestral centromere and its flanking regions, gaining insight into the ancestral organization that can be easily broadened to all acrocentric chromosome centromeres. Moreover, our analyses offered the opportunity to trace the evolutionary history of rDNA and satellite III sequences among great apes, thus suggesting a new hypothesis for the preferential inactivation of some human centromeres, including IIq. Our results suggest two possible centromere inactivation models to explain the evolutionarily stabilization of human chromosome 2 over the last 5-6 million years. Our results strongly favor centromere excision through a one-step process. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Telomere dysfunction and chromosome structure modulate the contribution of individual chromosomes in abnormal nuclear morphologies

Energy Technology Data Exchange (ETDEWEB)

Pampalona, J.; Soler, D.; Genesca, A. [Department of Cell Biology, Physiology and Immunology, Universitat Autonoma de Barcelona, Bellaterra E-08193 (Spain); Tusell, L., E-mail: laura.tusell@uab.es [Department of Cell Biology, Physiology and Immunology, Universitat Autonoma de Barcelona, Bellaterra E-08193 (Spain)

2010-01-05

The cytokinesis-block micronucleus assay has emerged as a biomarker of chromosome damage relevant to cancer. Although it was initially developed to measure micronuclei, it is also useful for measuring nucleoplasmic bridges and nuclear buds. Abnormal nuclear morphologies are frequently observed in malignant tissues and short-term tumour cell cultures. Changes in chromosome structure and number resulting from chromosome instability are important factors in oncogenesis. Telomeres have become key players in the initiation of chromosome instability related to carcinogenesis by means of breakage-fusion-bridge cycles. To better understand the connection between telomere dysfunction and the appearance of abnormal nuclear morphologies, we have characterised the presence of micronuclei, nucleoplasmic bridges and nuclear buds in human mammary primary epithelial cells. These cells can proliferate beyond the Hayflick limit by spontaneously losing expression of the p16{sup INK4a} protein. Progressive telomere shortening leads to the loss of the capping function, and the appearance of end-to-end chromosome fusions that can enter into breakage-fusion-bridge cycles generating massive chromosomal instability. In human mammary epithelial cells, different types of abnormal nuclear morphologies were observed, however only nucleoplasmatic bridges and buds increased significantly with population doublings. Fluorescent in situ hybridisation using centromeric and painting specific probes for chromosomes with eroded telomeres has revealed that these chromosomes are preferentially included in the different types of abnormal nuclear morphologies observed, thus reflecting their common origin. Accordingly, real-time imaging of cell divisions enabled us to determine that anaphase bridge resolution was mainly through chromatin breakage and the formation of symmetric buds in daughter nuclei. Few micronuclei emerged in this cell system thus validating the scoring of nucleoplasmic bridges and

Telomere dysfunction and chromosome structure modulate the contribution of individual chromosomes in abnormal nuclear morphologies

International Nuclear Information System (INIS)

Pampalona, J.; Soler, D.; Genesca, A.; Tusell, L.

2010-01-01

The cytokinesis-block micronucleus assay has emerged as a biomarker of chromosome damage relevant to cancer. Although it was initially developed to measure micronuclei, it is also useful for measuring nucleoplasmic bridges and nuclear buds. Abnormal nuclear morphologies are frequently observed in malignant tissues and short-term tumour cell cultures. Changes in chromosome structure and number resulting from chromosome instability are important factors in oncogenesis. Telomeres have become key players in the initiation of chromosome instability related to carcinogenesis by means of breakage-fusion-bridge cycles. To better understand the connection between telomere dysfunction and the appearance of abnormal nuclear morphologies, we have characterised the presence of micronuclei, nucleoplasmic bridges and nuclear buds in human mammary primary epithelial cells. These cells can proliferate beyond the Hayflick limit by spontaneously losing expression of the p16 INK4a protein. Progressive telomere shortening leads to the loss of the capping function, and the appearance of end-to-end chromosome fusions that can enter into breakage-fusion-bridge cycles generating massive chromosomal instability. In human mammary epithelial cells, different types of abnormal nuclear morphologies were observed, however only nucleoplasmatic bridges and buds increased significantly with population doublings. Fluorescent in situ hybridisation using centromeric and painting specific probes for chromosomes with eroded telomeres has revealed that these chromosomes are preferentially included in the different types of abnormal nuclear morphologies observed, thus reflecting their common origin. Accordingly, real-time imaging of cell divisions enabled us to determine that anaphase bridge resolution was mainly through chromatin breakage and the formation of symmetric buds in daughter nuclei. Few micronuclei emerged in this cell system thus validating the scoring of nucleoplasmic bridges and nuclear

Telomere dysfunction and chromosome structure modulate the contribution of individual chromosomes in abnormal nuclear morphologies.

Science.gov (United States)

Pampalona, J; Soler, D; Genescà, A; Tusell, L

2010-01-05

The cytokinesis-block micronucleus assay has emerged as a biomarker of chromosome damage relevant to cancer. Although it was initially developed to measure micronuclei, it is also useful for measuring nucleoplasmic bridges and nuclear buds. Abnormal nuclear morphologies are frequently observed in malignant tissues and short-term tumour cell cultures. Changes in chromosome structure and number resulting from chromosome instability are important factors in oncogenesis. Telomeres have become key players in the initiation of chromosome instability related to carcinogenesis by means of breakage-fusion-bridge cycles. To better understand the connection between telomere dysfunction and the appearance of abnormal nuclear morphologies, we have characterised the presence of micronuclei, nucleoplasmic bridges and nuclear buds in human mammary primary epithelial cells. These cells can proliferate beyond the Hayflick limit by spontaneously losing expression of the p16(INK4a) protein. Progressive telomere shortening leads to the loss of the capping function, and the appearance of end-to-end chromosome fusions that can enter into breakage-fusion-bridge cycles generating massive chromosomal instability. In human mammary epithelial cells, different types of abnormal nuclear morphologies were observed, however only nucleoplasmatic bridges and buds increased significantly with population doublings. Fluorescent in situ hybridisation using centromeric and painting specific probes for chromosomes with eroded telomeres has revealed that these chromosomes are preferentially included in the different types of abnormal nuclear morphologies observed, thus reflecting their common origin. Accordingly, real-time imaging of cell divisions enabled us to determine that anaphase bridge resolution was mainly through chromatin breakage and the formation of symmetric buds in daughter nuclei. Few micronuclei emerged in this cell system thus validating the scoring of nucleoplasmic bridges and nuclear

Reactivation of chromosomally integrated human herpesvirus-6 by telomeric circle formation.

Directory of Open Access Journals (Sweden)

Bhupesh K Prusty

Full Text Available More than 95% of the human population is infected with human herpesvirus-6 (HHV-6 during early childhood and maintains latent HHV-6 genomes either in an extra-chromosomal form or as a chromosomally integrated HHV-6 (ciHHV-6. In addition, approximately 1% of humans are born with an inheritable form of ciHHV-6 integrated into the telomeres of chromosomes. Immunosuppression and stress conditions can reactivate latent HHV-6 replication, which is associated with clinical complications and even death. We have previously shown that Chlamydia trachomatis infection reactivates ciHHV-6 and induces the formation of extra-chromosomal viral DNA in ciHHV-6 cells. Here, we propose a model and provide experimental evidence for the mechanism of ciHHV-6 reactivation. Infection with Chlamydia induced a transient shortening of telomeric ends, which subsequently led to increased telomeric circle (t-circle formation and incomplete reconstitution of circular viral genomes containing single viral direct repeat (DR. Correspondingly, short t-circles containing parts of the HHV-6 DR were detected in cells from individuals with genetically inherited ciHHV-6. Furthermore, telomere shortening induced in the absence of Chlamydia infection also caused circularization of ciHHV-6, supporting a t-circle based mechanism for ciHHV-6 reactivation.

Homologous alpha satellite sequences on human acrocentric chromosomes with selectivity for chromosomes 13, 14, and 21: implications for recombination between nonhomologues and Robertsonian translocations

Energy Technology Data Exchange (ETDEWEB)

Choo, K H; Vissel, B; Brown, R; Filby, R G; Earle, E

1988-02-25

The authors report a new subfamily of alpha satellite DNA (pTRA-2) which is found on all the human acrocentric chromosomes. The alphoid nature of the cloned DNA was established by partial sequencing. Southern analysis of restriction enzyme-digested DNA fragments from mouse/human hybrid cells containing only human chromosome 21 showed that the predominant higher-order repeating unit for pTRA-2 is a 3.9 kb structure. Analysis of a consensus in situ hybridization profile derived from 13 normal individuals revealed the localization of 73% of all centromeric autoradiographic grains over the five acrocentric chromosomes, with the following distribution: 20.4%, 21.5%, 17.1%, 7.3% and 6.5% on chromosomes 13, 14, 21, 15 and 22 respectively. An average of 1.4% of grains was found on the centromere of each of the remaining 19 nonacrocentric chromosomes. These results indicate the presence of a common subfamily of alpha satellite DNA on the five acrocentric chromosomes and suggest an evolutionary process consistent with recombination exchange of sequences between the nonhomologues. The results further suggests that such exchanges are more selective for chromosomes 13, 14 and 21 than for chromosomes 15 and 22. The possible role of centromeric alpha satellite DNA in the aetiology of 13q14q and 14q21q Robertsonian translocation involving the common and nonrandom association of chromosomes 13 and 14, and 14 and 21 is discussed.

Termini of human chromosomes display elevated rates of mitotic recombination.

Science.gov (United States)

Cornforth, M N; Eberle, R L

2001-01-01

The strand-specific in situ hybridization technique of CO-FISH was used to probe telomeres of human mitotic cells in order to determine the spontaneous frequency of crossover. This approach allowed the detection of recombinational crossovers occurring anywhere along the length of individual chromosomes, including reciprocal events taking place between sister chromatids. Although the process of sister chromatid exchange (SCE) is the most prominent type of recombination in somatic mammalian cells, our results show that SCEs accounted for less than a third of the recombinational events revealed by CO-FISH. It is concluded that chromosomal regions near the termini of chromosome arms undergo extraordinarily high rates of spontaneous recombination, producing terminal crossovers whose small size precludes detection by standard cytogenetic methods. That similar results were observed for transformed epithelial cells, as well as primary fibroblasts, suggests that the phenomenon is a common characteristic of human cells. These findings are noteworthy because, although telomeric and subtelomeric DNA is known to be preferentially involved in certain types of recombination, the tips of somatic mammalian chromosomes have not previously been identified as preferred sites for crossover. Implications of these results are discussed in terms of limitations imposed on CO-FISH for its proposed use in directional hybridization mapping.

Identification of a herpes simplex labialis susceptibility region on human chromosome 21.

Science.gov (United States)

Hobbs, Maurine R; Jones, Brandt B; Otterud, Brith E; Leppert, Mark; Kriesel, John D

2008-02-01

Most of the United States population is infected with either herpes simplex virus type 1 (HSV-1), herpes simplex virus type 2, or both. Reactivations of HSV-1 infection cause herpes simplex labialis (HSL; cold sores or fever blisters), which is the most common recurring viral infection in humans. To investigate the possibility of a human genetic component conferring resistance or susceptibility to cold sores (i.e., a HSL susceptibility gene), we conducted a genetic linkage analysis that included serotyping and phenotyping 421 individuals from 39 families enrolled in the Utah Genetic Reference Project. Linkage analysis identified a 2.5-Mb nonrecombinant region of interest on the long arm of human chromosome 21, with a multipoint logarithm of odds score of 3.9 noted near marker abmc65 (D21S409). Nonparametric linkage analysis of the data also provided strong evidence for linkage (P = .0005). This region of human chromosome 21 contains 6 candidate genes for herpes susceptibility. The development of frequent cold sores is associated with a region on the long arm of human chromosome 21. This region contains several candidate genes that could influence the frequency of outbreaks of HSL.

Preparation and bivariate analysis of suspensions of human chromosomes

Energy Technology Data Exchange (ETDEWEB)

van den Engh, G.J.; Trask, B.J.; Gray, J.W.; Langlois, R.G.; Yu, L.C.

1985-01-01

Chromosomes were isolated from a variety of human cell types using a HEPES-buffered hypotonic solution (pH 8.0) containing KCl, MgSO/sub 4/ dithioerythritol, and RNase. The chromosomes isolated by this procedure could be stained with a variety of fluorescent stains including propidium iodide, chromomycin A3, and Hoeschst 33258. Addition of sodium citrate to the stained chromosomes was found to improve the total fluorescence resolution. High-quality bivariate Hoeschst vs. chromomycin fluorescence distributions were obtained for chromosomes isolated from a human fibroblast cell strain, a human colon carcinoma cell line, and human peripheral blood lymphocyte cultures. Good flow karyotypes were also obtained from primary amniotic cell cultures. The Hoeschst vs. chromomycin flow karyotypes of a given cell line, made at different times and at dye concentrations varying over fourfold ranges, show little variation in the relative peak positions of the chromosomes. The size of the DNA in chromosomes isolated using this procedure ranges from 20 to 50 kilobases. The described isolation procedure is simple, it yields high-quality flow karyotypes, and it can be used to prepare chromosomes from clinical samples. 22 references, 7 figures, 1 table.

A high-resolution comparative map between pig chromosome 17 and human chromosomes 4, 8, and 20: Identification of synteny breakpoints

DEFF Research Database (Denmark)

Lahbib-Mansais, Yvette; Karlskov-Mortensen, Peter; Mompart, Florence

2005-01-01

We report on the construction of a high-resolution comparative map of porcine chromosome 17 (SSC17) focusing on evolutionary breakpoints with human chromosomes. The comparative map shows high homology with human chromosome 20 but suggests more limited homologies with other human chromosomes. SSC1...

The distribution of chromosome aberrations among chromosomes of karyotype in exposed human lymphocyte

International Nuclear Information System (INIS)

Que Tran; Tien Hoang Hung

1997-01-01

Induced chromosome aberrations (ch. ab.) in exposed Human peripheral blood lymphocyte have been used to assay radio.bio.doses, because of their characters such as: the maintaining Go phase in cell cycle in body, the distribution of cell in blood system and the distribution of ch. ab. in exposed cells of body and among chromosomes of karyotype. The frequency of ch. ab. reflected the quantity of radiation dose, dose rate and radiation energy. The dependence between radiation dose and frequency of ch. ab. was illustrated by the mathematic equations. The distribution of induced ch. ab. among the cells exposed to uniform radiation fields was Poisson's, but the distribution of ch. ab. among chromosomes in karyotype depended on radiation field and mononucleotid sequence of DNA molecular of each chromosome. The minimum influence of mononucleotid sequence of DNA molecular in inform ch. ab. will be advantageous state for dose-assessments. The location of induced ch. ab. in exposed Human lymphocyte had been determined by karyotype analyses. The data of statistic analyse had improved that the number of ch. ab. depended on the size of chromosomes in karyotype. The equal distribution of ch. ab.among chromosomes in karyotype provided the objectiveness and the accuracy of using the chromosomal aberrant analysis technique on bio-dosimetry. (author)

Frequency and distribution analysis of chromosomal translocations induced by x-ray in human lymphocytes

International Nuclear Information System (INIS)

Lopez Hidalgo, Juana Ines

2000-01-01

The characteristic of ionizing radiation suggests that induced chromosomal damage in the form of translocations would appear to be randomly distributed. However, the outcome of tests performed in vitro and in vivo (irradiated individuals) are contradictories. The most translocation-related chromosomes, as far as some studies reveal on one hand, appear to be less involved in accordance with others. These data, together with those related to molecular mechanisms involved in translocations production suggest that in G 0 -irradiated cells, the frequency and distribution of this kind of chromosomal rearrangement, does not take place at random. They seem to be affected by in-nucleus chromosome distribution, by each chromosome's DNA length and functional features, by the efficiency of DNA repair mechanisms, and by inter individual differences. The objective of this study was to establish the frequency pattern of each human chromosome involved in radio-induced translocations, as well as to analyze the importance the chromosome length, the activity of DNA polymerase- dependant repair mechanisms, and inter individual differences within the scope of such distribution. To achieve the goals, peripheral blood lymphocytes from healthy donors were irradiated in presence and absence of 2'-3' dideoxithimidine (ddThd), a Β - DNA polymerase inhibitor, which takes part in the base repair mechanism (B E R). The results showed that: The presence of ddThd during the irradiation increase the basal frequency of radioinduced translocations in 60 %. This result suggests that ddThd repair synthesis inhibition can be in itself a valid methodology for radiation-induced bases damage assessment, damage which if not BER-repaired may result in translocation-leading double strand breaks. A statistically significant correlation between translocation frequency and chromosome length, in terms of percentage of genome, has been noticed both in (basal) irradiation and in irradiation with ddThd inhibitor

Human acrocentric chromosomes with transcriptionally silent nucleolar organizer regions associate with nucleoli

OpenAIRE

Sullivan, Gareth J.; Bridger, Joanna M.; Cuthbert, Andrew P.; Newbold, Robert F.; Bickmore, Wendy A.; McStay, Brian

2001-01-01

Human ribosomal gene repeats are distributed among five nucleolar organizer regions (NORs) on the p arms of acrocentric chromosomes. On exit from mitosis, nucleoli form around individual active NORs. As cells progress through the cycle, these mini-nucleoli fuse to form large nucleoli incorporating multiple NORs. It is generally assumed that nucleolar incorporation of individual NORs is dependent on ribosomal gene transcription. To test this assumption, we determined the nuclear location of in...

Chromosome aberrations: plants to human and Feulgen to FISH

International Nuclear Information System (INIS)

Natarajan, A.T.

2005-01-01

Chromosome aberrations and their impact on human health have been recognized for a long time. In the 1950s, in India, studies on induced chromosome aberrations in plants were initiated by Swaminathan and his students. I trace here the impact of these initial studies on further developments in this field. The studies which were started in plants have been extended to mammals (including human) and the simple squash and solid staining have been improved by molecular cytogenetic techniques, thus enabling accurate identification and quantification of different types of chromosome aberrations. These studies have also thrown light on the mechanisms of chromosome aberration formation, especially following exposure to ionizing radiation. (author)

Human oocyte chromosome analysis: complicated cases and major ...

Indian Academy of Sciences (India)

Human oocyte chromosome analysis: complicated cases and major ... dardized even after more than 20 years of research, making it difficult to draw .... (c) Part of a metaphase with a chromosome break in the centromeric region (arrows).

Chromosomal localization of the human and mouse hyaluronan synthase genes

Energy Technology Data Exchange (ETDEWEB)

Spicer, A.P.; McDonald, J.A. [Mayo Clinic Scottsdale, AZ (United States); Seldin, M.F. [Univ. of California Davis, CA (United States)] [and others

1997-05-01

We have recently identified a new vertebrate gene family encoding putative hyaluronan (HA) synthases. Three highly conserved related genes have been identified, designated HAS1, HAS2, and HAS3 in humans and Has1, Has2, and Has3 in the mouse. All three genes encode predicted plasma membrane proteins with multiple transmembrane domains and approximately 25% amino acid sequence identity to the Streptococcus pyogenes HA synthase, HasA. Furthermore, expression of any one HAS gene in transfected mammalian cells leads to high levels of HA biosynthesis. We now report the chromosomal localization of the three HAS genes in human and in mouse. The genes localized to three different positions within both the human and the mouse genomes. HAS1 was localized to the human chromosome 19q13.3-q13.4 boundary and Has1 to mouse Chr 17. HAS2 was localized to human chromosome 8q24.12 and Has2 to mouse Chr 15. HAS3 was localized to human chromosome 16q22.1 and Has3 to mouse Chr 8. The map position for HAS1 reinforces the recently reported relationship between a small region of human chromosome 19q and proximal mouse chromosome 17. HAS2 mapped outside the predicted critical region delineated for the Langer-Giedion syndrome and can thus be excluded as a candidate gene for this genetic syndrome. 33 refs., 2 figs.

Human oocyte chromosome analyses need a standardized ...

Indian Academy of Sciences (India)

Studies of DNA polymorphisms in human trisomic abor- tions and liveborn have ... Keywords. human oocyte chromosomes; cytogenetic analysis; aneuploidy; nondisjunction; predivision. Journal of .... oocytes and giant embryos. Hum. Reprod.

Chromosomal localization of the gonadotropin-releasing hormone receptor gene to human chromosome 4q13. 1-q21. 1 and mouse chromosome 5

Energy Technology Data Exchange (ETDEWEB)

Kaiser, U.B.; Dushkin, H.; Beier, D.R.; Chin, W.W. (Harvard Medical School, Boston, MA (United States)); Altherr, M.R. (Los Alamos National Lab., NM (United States))

1994-04-01

The gonadotropin-releasing hormone receptor (GRHR) is a G-protein-coupled receptor on the cell surface of pituitary gonadotropes, where it serves to transduce signals from the extracellular ligand, the hypothalamic factor gonadotropin-releasing hormone, and to modulate the synthesis and secretion of luteinizing hormone and follicle-stimulating hormone. The authors have localized the GRHR gene to the q13.1-q21.1 region of the human chromosome 4 using mapping panels of human/rodent somatic cell hybrids containing different human chromosomes or different regions of human chromosome 4. Furthermore, using linkage analysis of single-strand conformational polymorphisms, the murine GRHR gene was localized to mouse chromosome 5, linked to the endogenous retroviral marker Pmv-11. This is consistent with the evolutionary conservation of homology between these two regions, as has been previously suggested from comparative mapping of several other loci. The localization of the GRHR gene may be useful in the study of disorders of reproduction. 22 refs., 2 figs.

Mechanisms of ring chromosome formation in 11 cases of human ring chromosome 21

DEFF Research Database (Denmark)

McGinniss, M J; Kazazian, H H; Stetten, G

1992-01-01

We studied the mechanism of ring chromosome 21 (r(21)) formation in 13 patients (11 unique r(21)s), consisting of 7 from five families with familial r(21) and 6 with de novo r(21). The copy number of chromosome 21 sequences in the rings of these patients was determined by quantitative dosage......), resulting in deletion of varying amounts of 21q22.1 to 21qter. The data from one individual who had a Down syndrome phenotype were consistent with asymmetric breakage and reunion of 21q sequences from an intermediate isochromosome or Robertsonian translocation chromosome as reported by Wong et al. Another......). The phenotype of patients correlated well with the extent of deletion or duplication of chromosome 21 sequences. These data demonstrate three mechanisms of r(21) formation and show that the phenotype of r(21) patients varies with the extent of chromosome 21 monosomy or trisomy....

Roles of the Y chromosome genes in human cancers

Directory of Open Access Journals (Sweden)

Tatsuo Kido

2015-06-01

Full Text Available Male and female differ genetically by their respective sex chromosome composition, that is, XY as male and XX as female. Although both X and Y chromosomes evolved from the same ancestor pair of autosomes, the Y chromosome harbors male-specific genes, which play pivotal roles in male sex determination, germ cell differentiation, and masculinization of various tissues. Deletions or translocation of the sex-determining gene, SRY, from the Y chromosome causes disorders of sex development (previously termed as an intersex condition with dysgenic gonads. Failure of gonadal development results not only in infertility, but also in increased risks of germ cell tumor (GCT, such as gonadoblastoma and various types of testicular GCT. Recent studies demonstrate that either loss of Y chromosome or ectopic expression of Y chromosome genes is closely associated with various male-biased diseases, including selected somatic cancers. These observations suggest that the Y-linked genes are involved in male health and diseases in more frequently than expected. Although only a small number of protein-coding genes are present in the male-specific region of Y chromosome, the impacts of Y chromosome genes on human diseases are still largely unknown, due to lack of in vivo models and differences between the Y chromosomes of human and rodents. In this review, we highlight the involvement of selected Y chromosome genes in cancer development in men.

Flow cytometry measurements of human chromosome kinetochore labeling

International Nuclear Information System (INIS)

Fantes, J.A.; Green, D.K.; Malloy, P.; Sumner, A.T.

1989-01-01

A method for the preparation and measurement of immunofluorescent human chromosome centromeres in suspension is described using CREST antibodies, which bind to the centromeric region of chromosomes. Fluorescein isothiocyanate (FITC)-conjugated antihuman antibodies provide the fluorescent label. Labeled chromosomes are examined on microscope slides and by flow cytometry. In both cases a dye which binds to DNA is added to provide identification of the chromosome groups. Sera from different CREST patients vary in their ability to bind to chromosome arms in addition to the centromeric region. Flow cytometry and microfluorimetry measurements have shown that with a given CREST serum the differences in kinetochore fluorescence between chromosomes are only minor. Flow cytometry experiments to relate the number of dicentric chromosomes, induced by in vitro radiation of peripheral blood cells to the slightly increased number of chromosomes with above-average kinetochore fluorescence did not produce decisive radiation dosimetry results

Characterization of a chromosome-specific chimpanzee alpha satellite subset: Evolutionary relationship to subsets on human chromosomes

Energy Technology Data Exchange (ETDEWEB)

Warburton, P.E.; Gosden, J.; Lawson, D. [Western General Hospital, Edinburgh (United Kingdom)] [and others

1996-04-15

Alpha satellite DNA is a tandemly repeated DNA family found at the centromeres of all primate chromosomes examined. The fundamental repeat units of alpha satellite DNA are diverged 169- to 172-bp monomers, often found to be organized in chromosome-specific higher-order repeat units. The chromosomes of human (Homo sapiens (HSA)), chimpanzee (Pan troglodytes (PTR) and Pan paniscus), and gorilla (Gorilla gorilla) share a remarkable similarity and synteny. It is of interest to ask if alpha satellite arrays at centromeres of homologous chromosomes between these species are closely related (evolving in an orthologous manner) or if the evolutionary processes that homogenize and spread these arrays within and between chromosomes result in nonorthologous evolution of arrays. By using PCR primers specific for human chromosome 17-specific alpha satellite DNA, we have amplified, cloned, and characterized a chromosome-specific subset from the PTR chimpanzee genome. Hybridization both on Southern blots and in situ as well as sequence analysis show that this subset is most closely related, as expected, to sequences on HSA 17. However, in situ hybridization reveals that this subset is not found on the homologous chromosome in chimpanzee (PTR 19), but instead on PTR 12, which is homologous to HSA 2p. 40 refs., 3 figs.

Chromosome microdissection and cloning in human genome and genetic disease analysis

International Nuclear Information System (INIS)

Kao, Faten; Yu, Jingwei

1991-01-01

A procedure has been described for microdissection and microcloning of human chromosomal DNA sequences in which universal amplification of the dissected fragments by Mbo I linker adaptor and polymerase chain reaction is used. A very large library comprising 700,000 recombinant plasmid microclones from 30 dissected chromosomes of human chromosome 21 was constructed. Colony hybridization showed that 42% of the clones contained repetitive sequences and 58% contained single or low-copy sequences. The insert sizes generated by complete Mbo I cleavage ranged from 50 to 1,100 base pairs with a mean of 416 base pairs. Southern blot analysis of microclones from the library confirmed their human origin and chromosome 21 specificity. Some of these clones have also been regionally mapped to specific sites of chromosome 21 by using a regional mapping panel of cell hybrids. This chromosome microtechnology can generate large numbers of microclones with unique sequences from defined chromosomal regions and can be used for processes such as (i) isolating corresponding yeast artificial chromosome clones with large inserts, (ii) screening various cDNA libraries for isolating expressed sequences, and (iii) constructing region-specific libraries of the entire human genome. The studies described here demonstrate the power of this technology for high-resolution genome analysis and explicate their use in an efficient search for disease-associated genes localized to specific chromosomal regions

Meiotic recombination analyses of individual chromosomes in male domestic pigs (Sus scrofa domestica.

Directory of Open Access Journals (Sweden)

Nicolas Mary

Full Text Available For the first time in the domestic pig, meiotic recombination along the 18 porcine autosomes was directly studied by immunolocalization of MLH1 protein. In total, 7,848 synaptonemal complexes from 436 spermatocytes were analyzed, and 13,969 recombination sites were mapped. Individual chromosomes for 113 of the 436 cells (representing 2,034 synaptonemal complexes were identified by immunostaining and fluorescence in situ hybridization (FISH. The average total length of autosomal synaptonemal complexes per cell was 190.3 µm, with 32.0 recombination sites (crossovers, on average, per cell. The number of crossovers and the lengths of the autosomal synaptonemal complexes showed significant intra- (i.e. between cells and inter-individual variations. The distributions of recombination sites within each chromosomal category were similar: crossovers in metacentric and submetacentric chromosomes were concentrated in the telomeric regions of the p- and q-arms, whereas two hotspots were located near the centromere and in the telomeric region of acrocentrics. Lack of MLH1 foci was mainly observed in the smaller chromosomes, particularly chromosome 18 (SSC18 and the sex chromosomes. All autosomes displayed positive interference, with a large variability between the chromosomes.

The DNA sequence of the human X chromosome

Science.gov (United States)

Ross, Mark T.; Grafham, Darren V.; Coffey, Alison J.; Scherer, Steven; McLay, Kirsten; Muzny, Donna; Platzer, Matthias; Howell, Gareth R.; Burrows, Christine; Bird, Christine P.; Frankish, Adam; Lovell, Frances L.; Howe, Kevin L.; Ashurst, Jennifer L.; Fulton, Robert S.; Sudbrak, Ralf; Wen, Gaiping; Jones, Matthew C.; Hurles, Matthew E.; Andrews, T. Daniel; Scott, Carol E.; Searle, Stephen; Ramser, Juliane; Whittaker, Adam; Deadman, Rebecca; Carter, Nigel P.; Hunt, Sarah E.; Chen, Rui; Cree, Andrew; Gunaratne, Preethi; Havlak, Paul; Hodgson, Anne; Metzker, Michael L.; Richards, Stephen; Scott, Graham; Steffen, David; Sodergren, Erica; Wheeler, David A.; Worley, Kim C.; Ainscough, Rachael; Ambrose, Kerrie D.; Ansari-Lari, M. Ali; Aradhya, Swaroop; Ashwell, Robert I. S.; Babbage, Anne K.; Bagguley, Claire L.; Ballabio, Andrea; Banerjee, Ruby; Barker, Gary E.; Barlow, Karen F.; Barrett, Ian P.; Bates, Karen N.; Beare, David M.; Beasley, Helen; Beasley, Oliver; Beck, Alfred; Bethel, Graeme; Blechschmidt, Karin; Brady, Nicola; Bray-Allen, Sarah; Bridgeman, Anne M.; Brown, Andrew J.; Brown, Mary J.; Bonnin, David; Bruford, Elspeth A.; Buhay, Christian; Burch, Paula; Burford, Deborah; Burgess, Joanne; Burrill, Wayne; Burton, John; Bye, Jackie M.; Carder, Carol; Carrel, Laura; Chako, Joseph; Chapman, Joanne C.; Chavez, Dean; Chen, Ellson; Chen, Guan; Chen, Yuan; Chen, Zhijian; Chinault, Craig; Ciccodicola, Alfredo; Clark, Sue Y.; Clarke, Graham; Clee, Chris M.; Clegg, Sheila; Clerc-Blankenburg, Kerstin; Clifford, Karen; Cobley, Vicky; Cole, Charlotte G.; Conquer, Jen S.; Corby, Nicole; Connor, Richard E.; David, Robert; Davies, Joy; Davis, Clay; Davis, John; Delgado, Oliver; DeShazo, Denise; Dhami, Pawandeep; Ding, Yan; Dinh, Huyen; Dodsworth, Steve; Draper, Heather; Dugan-Rocha, Shannon; Dunham, Andrew; Dunn, Matthew; Durbin, K. James; Dutta, Ireena; Eades, Tamsin; Ellwood, Matthew; Emery-Cohen, Alexandra; Errington, Helen; Evans, Kathryn L.; Faulkner, Louisa; Francis, Fiona; Frankland, John; Fraser, Audrey E.; Galgoczy, Petra; Gilbert, James; Gill, Rachel; Glöckner, Gernot; Gregory, Simon G.; Gribble, Susan; Griffiths, Coline; Grocock, Russell; Gu, Yanghong; Gwilliam, Rhian; Hamilton, Cerissa; Hart, Elizabeth A.; Hawes, Alicia; Heath, Paul D.; Heitmann, Katja; Hennig, Steffen; Hernandez, Judith; Hinzmann, Bernd; Ho, Sarah; Hoffs, Michael; Howden, Phillip J.; Huckle, Elizabeth J.; Hume, Jennifer; Hunt, Paul J.; Hunt, Adrienne R.; Isherwood, Judith; Jacob, Leni; Johnson, David; Jones, Sally; de Jong, Pieter J.; Joseph, Shirin S.; Keenan, Stephen; Kelly, Susan; Kershaw, Joanne K.; Khan, Ziad; Kioschis, Petra; Klages, Sven; Knights, Andrew J.; Kosiura, Anna; Kovar-Smith, Christie; Laird, Gavin K.; Langford, Cordelia; Lawlor, Stephanie; Leversha, Margaret; Lewis, Lora; Liu, Wen; Lloyd, Christine; Lloyd, David M.; Loulseged, Hermela; Loveland, Jane E.; Lovell, Jamieson D.; Lozado, Ryan; Lu, Jing; Lyne, Rachael; Ma, Jie; Maheshwari, Manjula; Matthews, Lucy H.; McDowall, Jennifer; McLaren, Stuart; McMurray, Amanda; Meidl, Patrick; Meitinger, Thomas; Milne, Sarah; Miner, George; Mistry, Shailesh L.; Morgan, Margaret; Morris, Sidney; Müller, Ines; Mullikin, James C.; Nguyen, Ngoc; Nordsiek, Gabriele; Nyakatura, Gerald; O’Dell, Christopher N.; Okwuonu, Geoffery; Palmer, Sophie; Pandian, Richard; Parker, David; Parrish, Julia; Pasternak, Shiran; Patel, Dina; Pearce, Alex V.; Pearson, Danita M.; Pelan, Sarah E.; Perez, Lesette; Porter, Keith M.; Ramsey, Yvonne; Reichwald, Kathrin; Rhodes, Susan; Ridler, Kerry A.; Schlessinger, David; Schueler, Mary G.; Sehra, Harminder K.; Shaw-Smith, Charles; Shen, Hua; Sheridan, Elizabeth M.; Shownkeen, Ratna; Skuce, Carl D.; Smith, Michelle L.; Sotheran, Elizabeth C.; Steingruber, Helen E.; Steward, Charles A.; Storey, Roy; Swann, R. Mark; Swarbreck, David; Tabor, Paul E.; Taudien, Stefan; Taylor, Tineace; Teague, Brian; Thomas, Karen; Thorpe, Andrea; Timms, Kirsten; Tracey, Alan; Trevanion, Steve; Tromans, Anthony C.; d’Urso, Michele; Verduzco, Daniel; Villasana, Donna; Waldron, Lenee; Wall, Melanie; Wang, Qiaoyan; Warren, James; Warry, Georgina L.; Wei, Xuehong; West, Anthony; Whitehead, Siobhan L.; Whiteley, Mathew N.; Wilkinson, Jane E.; Willey, David L.; Williams, Gabrielle; Williams, Leanne; Williamson, Angela; Williamson, Helen; Wilming, Laurens; Woodmansey, Rebecca L.; Wray, Paul W.; Yen, Jennifer; Zhang, Jingkun; Zhou, Jianling; Zoghbi, Huda; Zorilla, Sara; Buck, David; Reinhardt, Richard; Poustka, Annemarie; Rosenthal, André; Lehrach, Hans; Meindl, Alfons; Minx, Patrick J.; Hillier, LaDeana W.; Willard, Huntington F.; Wilson, Richard K.; Waterston, Robert H.; Rice, Catherine M.; Vaudin, Mark; Coulson, Alan; Nelson, David L.; Weinstock, George; Sulston, John E.; Durbin, Richard; Hubbard, Tim; Gibbs, Richard A.; Beck, Stephan; Rogers, Jane; Bentley, David R.

2009-01-01

The human X chromosome has a unique biology that was shaped by its evolution as the sex chromosome shared by males and females. We have determined 99.3% of the euchromatic sequence of the X chromosome. Our analysis illustrates the autosomal origin of the mammalian sex chromosomes, the stepwise process that led to the progressive loss of recombination between X and Y, and the extent of subsequent degradation of the Y chromosome. LINE1 repeat elements cover one-third of the X chromosome, with a distribution that is consistent with their proposed role as way stations in the process of X-chromosome inactivation. We found 1,098 genes in the sequence, of which 99 encode proteins expressed in testis and in various tumour types. A disproportionately high number of mendelian diseases are documented for the X chromosome. Of this number, 168 have been explained by mutations in 113 X-linked genes, which in many cases were characterized with the aid of the DNA sequence. PMID:15772651

Chromosomal location of the human gene for DNA polymerase β

International Nuclear Information System (INIS)

McBride, O.W.; Zmudzka, B.Z.; Wilson, S.H.

1987-01-01

Inhibition studies indicate that DNA polymerase β has a synthetic role in DNA repair after exposure of mammalian cells to some types of DNA-damaging agents. The primary structure of the enzyme is highly conserved in vertebrates, and nearly full-length cDNAs for the enzyme were recently cloned from mammalian cDNA libraries. Southern blot analysis of DNA from a panel of human-rodent somatic cell hybrids, using portions of the cDNA as probe, indicates that the gene for human DNA polymerase β is single copy and located on the short arm or proximal long arm of chromosome 8 (8pter-8q22). A restriction fragment length polymorphism (RFLP) was detected in normal individuals by using a probe from the 5' end of the cDNA, and this RFLP probably is due to an insertion or duplication of DNA in 20-25% of the population. This restriction site can be used as one marker for chromosome 8 genetic linkage studies and for family studies of traits potentially involving this DNA repair gene

Telomere disruption results in non-random formation of de novo dicentric chromosomes involving acrocentric human chromosomes.

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Kaitlin M Stimpson

2010-08-01

Full Text Available Genome rearrangement often produces chromosomes with two centromeres (dicentrics that are inherently unstable because of bridge formation and breakage during cell division. However, mammalian dicentrics, and particularly those in humans, can be quite stable, usually because one centromere is functionally silenced. Molecular mechanisms of centromere inactivation are poorly understood since there are few systems to experimentally create dicentric human chromosomes. Here, we describe a human cell culture model that enriches for de novo dicentrics. We demonstrate that transient disruption of human telomere structure non-randomly produces dicentric fusions involving acrocentric chromosomes. The induced dicentrics vary in structure near fusion breakpoints and like naturally-occurring dicentrics, exhibit various inter-centromeric distances. Many functional dicentrics persist for months after formation. Even those with distantly spaced centromeres remain functionally dicentric for 20 cell generations. Other dicentrics within the population reflect centromere inactivation. In some cases, centromere inactivation occurs by an apparently epigenetic mechanism. In other dicentrics, the size of the alpha-satellite DNA array associated with CENP-A is reduced compared to the same array before dicentric formation. Extra-chromosomal fragments that contained CENP-A often appear in the same cells as dicentrics. Some of these fragments are derived from the same alpha-satellite DNA array as inactivated centromeres. Our results indicate that dicentric human chromosomes undergo alternative fates after formation. Many retain two active centromeres and are stable through multiple cell divisions. Others undergo centromere inactivation. This event occurs within a broad temporal window and can involve deletion of chromatin that marks the locus as a site for CENP-A maintenance/replenishment.

Human chromosome-specific changes in a human-hamster hybrid cell line (AL) assessed by fluorescent in situ hybridization (fish)

International Nuclear Information System (INIS)

Geard, Charles R.; Jenkins, Gloria

1995-01-01

Purpose: To quantitatively assess all gamma-ray induced chromosomal changes confined to one human chromosome using fluorescence microscopy and in situ hybridization with a fluorescently labeled human chromosome specific nucleic acid probe. Methods and Materials: Synchronized human-hamster hybrid cells containing human chromosome 11 were obtained by a modified mitotic shake-off procedure. G1 phase cells (> 95%) were irradiated with 137 Cs gamma rays (0, 0.5, 1.0, 1.5, 2.0, 4.0, 6.0, 8.0, and 10.0 Gy) at a dose rate of 1.1 Gy/min and mitotic cells collected 16-20 h later; chromosomal spreads were prepared, denatured, and hybridized with a fluorescein-tagged nucleic acid probe against total human DNA. Chromosomes were examined by fluorescence microscopy and all categories of change involving the human chromosome 11 as target, recorded. Results: Overall, of the 3104 human-hamster hybrid cells examined, 82.1% were euploid, of which 88.6% contained one copy of human chromosome 11, 6.2% contained two copies, and 5.2% contained 0 copies. This is compatible with mitotic nondisjunction in a small fraction of cells. Of the remaining 17.9% of cells, 85.2% were tetraploid cells with two copies of human chromosome 11. For all aberrations involving human chromosome 11 there was a linear relationship between yield and absorbed dose of 0.1 aberrations per chromosome per Gy. The yield of dicentrics, translocations, and terminal deletions that involve one lesion on the human chromosome was linear, while the yield of interstitial deletions that arise from two interacting lesions on the human chromosome was curvilinear. The frequencies of dicentrics and translocations were about equal, while there was a high (40-60%) incidence of incomplete exchanges between human and hamster chromosomes. Conclusions: Fluorescent in situ hybridization (FISH) procedures allow for the efficient detection of a broad range of induced changes in target chromosomes. Symmetrical exchanges induced in G1

The study of human Y chromosome variation through ancient DNA.

Science.gov (United States)

Kivisild, Toomas

2017-05-01

High throughput sequencing methods have completely transformed the study of human Y chromosome variation by offering a genome-scale view on genetic variation retrieved from ancient human remains in context of a growing number of high coverage whole Y chromosome sequence data from living populations from across the world. The ancient Y chromosome sequences are providing us the first exciting glimpses into the past variation of male-specific compartment of the genome and the opportunity to evaluate models based on previously made inferences from patterns of genetic variation in living populations. Analyses of the ancient Y chromosome sequences are challenging not only because of issues generally related to ancient DNA work, such as DNA damage-induced mutations and low content of endogenous DNA in most human remains, but also because of specific properties of the Y chromosome, such as its highly repetitive nature and high homology with the X chromosome. Shotgun sequencing of uniquely mapping regions of the Y chromosomes to sufficiently high coverage is still challenging and costly in poorly preserved samples. To increase the coverage of specific target SNPs capture-based methods have been developed and used in recent years to generate Y chromosome sequence data from hundreds of prehistoric skeletal remains. Besides the prospects of testing directly as how much genetic change in a given time period has accompanied changes in material culture the sequencing of ancient Y chromosomes allows us also to better understand the rate at which mutations accumulate and get fixed over time. This review considers genome-scale evidence on ancient Y chromosome diversity that has recently started to accumulate in geographic areas favourable to DNA preservation. More specifically the review focuses on examples of regional continuity and change of the Y chromosome haplogroups in North Eurasia and in the New World.

Chromosome surveys of human populations: between epidemiology and anthropology.

Science.gov (United States)

de Chadarevian, Soraya

2014-09-01

It is commonly held that after 1945 human genetics turned medical and focussed on the individual rather than on the study of human populations that had become discredited. However, a closer look at the research practices at the time quickly reveals that human population studies, using old and new tools, prospered in this period. The essay focuses on the rise of chromosome analysis as a new tool for the study of human populations. It reviews a broad array of population studies ranging from newborn screening programmes to studies of isolated or 'primitive' people. Throughout, it highlights the continuing role of concerns and opportunities raised by the propagation of atomic energy for civilian and military uses, the collection of large data bases and computers, and the role of international organisations like the World Health Organisation and the International Biological Programme in shaping research agendas and carving out a space for human heredity in the postwar era. Copyright © 2014 Elsevier Ltd. All rights reserved.

Engineering of Systematic Elimination of a Targeted Chromosome in Human Cells.

Science.gov (United States)

Sato, Hiroshi; Kato, Hiroki; Yamaza, Haruyoshi; Masuda, Keiji; Nguyen, Huong Thi Nguyen; Pham, Thanh Thi Mai; Han, Xu; Hirofuji, Yuta; Nonaka, Kazuaki

2017-01-01

Embryonic trisomy leads to abortion or congenital genetic disorders in humans. The most common autosomal chromosome abnormalities are trisomy of chromosomes 13, 18, and 21. Although alteration of gene dosage is thought to contribute to disorders caused by extra copies of chromosomes, genes associated with specific disease phenotypes remain unclear. To generate a normal cell from a trisomic cell as a means of etiological analysis or candidate therapy for trisomy syndromes, we developed a system to eliminate a targeted chromosome from human cells. Chromosome 21 was targeted by integration of a DNA cassette in HeLa cells that harbored three copies of chromosome 21. The DNA cassette included two inverted loxP sites and a herpes simplex virus thymidine kinase (HSV-tk) gene. This system causes missegregation of chromosome 21 after expression of Cre recombinase and subsequently enables the selection of cells lacking the chromosome by culturing in a medium that includes ganciclovir (GCV). Cells harboring only two copies of chromosome 21 were efficiently induced by transfection of a Cre expression vector, indicating that this approach is useful for eliminating a targeted chromosome.

Human Chromosome 7: DNA Sequence and Biology

OpenAIRE

Scherer, Stephen W.; Cheung, Joseph; MacDonald, Jeffrey R.; Osborne, Lucy R.; Nakabayashi, Kazuhiko; Herbrick, Jo-Anne; Carson, Andrew R.; Parker-Katiraee, Layla; Skaug, Jennifer; Khaja, Razi; Zhang, Junjun; Hudek, Alexander K.; Li, Martin; Haddad, May; Duggan, Gavin E.

2003-01-01

DNA sequence and annotation of the entire human chromosome 7, encompassing nearly 158 million nucleotides of DNA and 1917 gene structures, are presented. To generate a higher order description, additional structural features such as imprinted genes, fragile sites, and segmental duplications were integrated at the level of the DNA sequence with medical genetic data, including 440 chromosome rearrangement breakpoints associated with disease. This approach enabled the discovery of candidate gene...

Natural Selection Reduced Diversity on Human Y Chromosomes

Science.gov (United States)

Wilson Sayres, Melissa A.; Lohmueller, Kirk E.; Nielsen, Rasmus

2014-01-01

The human Y chromosome exhibits surprisingly low levels of genetic diversity. This could result from neutral processes if the effective population size of males is reduced relative to females due to a higher variance in the number of offspring from males than from females. Alternatively, selection acting on new mutations, and affecting linked neutral sites, could reduce variability on the Y chromosome. Here, using genome-wide analyses of X, Y, autosomal and mitochondrial DNA, in combination with extensive population genetic simulations, we show that low observed Y chromosome variability is not consistent with a purely neutral model. Instead, we show that models of purifying selection are consistent with observed Y diversity. Further, the number of sites estimated to be under purifying selection greatly exceeds the number of Y-linked coding sites, suggesting the importance of the highly repetitive ampliconic regions. While we show that purifying selection removing deleterious mutations can explain the low diversity on the Y chromosome, we cannot exclude the possibility that positive selection acting on beneficial mutations could have also reduced diversity in linked neutral regions, and may have contributed to lowering human Y chromosome diversity. Because the functional significance of the ampliconic regions is poorly understood, our findings should motivate future research in this area. PMID:24415951

Biological radiation dose estimation by chromosomal aberrations analysis in human peripheral blood (dose-effect curve)

International Nuclear Information System (INIS)

Al-Achkar, W.

2001-09-01

In order to draw a dose-effect curve, experimentally gamma ray induced chromosomal aberrations in human peripheral lymphocytes from eight healthy people were studied. Samples from 4 males and 4 females were irradiated in tubes with 0.15, 0.25, 0.5, 1, 1.5, 2, 2.5 gray of gamma ray (Co 60 at dose rate 0.3 Gy/min). Irradiated and control samples were incubated in 37 centigrade for 48 hours cell cultures. Cell cultures then were stopped and metaphases spread, Giemsa stained to score the induced chromosomal aberrations. Chromosomal aberrations from 67888 metaphases were scored. Curves from the total number of dicentrics, dicentrics + rings and total numbers of breaks in cell for each individual or for all people were drawn. An increase of all chromosomal aberrations types with the elevation of the doses was observed. The yield of chromosome aberrations is related to the dose used. These curves give a quick useful estimation of the accidentally radiation exposure. (author)

Engineering of Systematic Elimination of a Targeted Chromosome in Human Cells

Directory of Open Access Journals (Sweden)

Hiroshi Sato

2017-01-01

Full Text Available Embryonic trisomy leads to abortion or congenital genetic disorders in humans. The most common autosomal chromosome abnormalities are trisomy of chromosomes 13, 18, and 21. Although alteration of gene dosage is thought to contribute to disorders caused by extra copies of chromosomes, genes associated with specific disease phenotypes remain unclear. To generate a normal cell from a trisomic cell as a means of etiological analysis or candidate therapy for trisomy syndromes, we developed a system to eliminate a targeted chromosome from human cells. Chromosome 21 was targeted by integration of a DNA cassette in HeLa cells that harbored three copies of chromosome 21. The DNA cassette included two inverted loxP sites and a herpes simplex virus thymidine kinase (HSV-tk gene. This system causes missegregation of chromosome 21 after expression of Cre recombinase and subsequently enables the selection of cells lacking the chromosome by culturing in a medium that includes ganciclovir (GCV. Cells harboring only two copies of chromosome 21 were efficiently induced by transfection of a Cre expression vector, indicating that this approach is useful for eliminating a targeted chromosome.

A worldwide phylogeography for the human X chromosome.

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Simone S Santos-Lopes

Full Text Available BACKGROUND: We reasoned that by identifying genetic markers on human X chromosome regions where recombination is rare or absent, we should be able to construct X chromosome genealogies analogous to those based on Y chromosome and mitochondrial DNA polymorphisms, with the advantage of providing information about both male and female components of the population. METHODOLOGY/PRINCIPAL FINDINGS: We identified a 47 Kb interval containing an Alu insertion polymorphism (DXS225 and four microsatellites in complete linkage disequilibrium in a low recombination rate region of the long arm of the human X chromosome. This haplotype block was studied in 667 males from the HGDP-CEPH Human Genome Diversity Panel. The haplotypic diversity was highest in Africa (0.992+/-0.0025 and lowest in the Americas (0.839+/-0.0378, where no insertion alleles of DXS225 were observed. Africa shared few haplotypes with other geographical areas, while those exhibited significant sharing among themselves. Median joining networks revealed that the African haplotypes were numerous, occupied the periphery of the graph and had low frequency, whereas those from the other continents were few, central and had high frequency. Altogether, our data support a single origin of modern man in Africa and migration to occupy the other continents by serial founder effects. Coalescent analysis permitted estimation of the time of the most recent common ancestor as 182,000 years (56,700-479,000 and the estimated time of the DXS225 Alu insertion of 94,400 years (24,300-310,000. These dates are fully compatible with the current widely accepted scenario of the origin of modern mankind in Africa within the last 195,000 years and migration out-of-Africa circa 55,000-65,000 years ago. CONCLUSIONS/SIGNIFICANCE: A haplotypic block combining an Alu insertion polymorphism and four microsatellite markers on the human X chromosome is a useful marker to evaluate genetic diversity of human populations and

Homologous subfamilies of human alphoid repetitive DNA on different nucleolus organizing chromosomes

International Nuclear Information System (INIS)

Joergensen, A.L.; Bostock, C.J.; Bak, A.L.

1987-01-01

The organization of alphoid repeated sequences on human nucleolus-organizing (NOR) chromosomes 13, 21, and 22 has been investigated. Analysis of hybridization of alphoid DNA probes to Southern transfers of restriction enzyme-digested DNA fragments from hybrid cells containing single human chromosomes shows that chromosomes 13 and 21 share one subfamily of alphoid repeats, whereas a different subfamily may be held in common by chromosomes 13 and 22. The sequences of cloned 680-base-pair EcoRI fragments of the alphoid DNA from chromosomes 13 and 21 show that the basic unit of this subfamily is indistinguishable on each chromosome. The sequence of cloned 1020-base-pair Xba I fragments from chromosome 22 is related to, but distinguishable from, that of the 680-base-pair EcoRI alphoid subfamily of chromosomes 13 and 21. These results suggest that, at some point after they originated and were homogenized, different subfamilies of alphoid sequences must have exchanged between chromosomes 13 and 21 and separately between chromosomes 13 and 22

Study of ionizing radiation effect on human spermatozoa chromosomes

International Nuclear Information System (INIS)

Rousseaux, S.

1990-02-01

The purpose of this thesis is to study the radio-induced chromosomal aberrations in spermatozoa. After a brief recall on ionizing radiations, the author reviews the radio-induced chromosomal anomalies on somatic cells and on germinal line cells and spermatozoa. The author presents the technical aspects of human spermatozoa karyotype and finally studies the radio induced chromosomal anomalies of sperm to patients undergoing a radiotherapy. 13 tabs., 28 figs., 28 photos

Structure, organization, and sequence of alpha satellite DNA from human chromosome 17: evidence for evolution by unequal crossing-over and an ancestral pentamer repeat shared with the human X chromosome.

Science.gov (United States)

Waye, J S; Willard, H F

1986-09-01

The centromeric regions of all human chromosomes are characterized by distinct subsets of a diverse tandemly repeated DNA family, alpha satellite. On human chromosome 17, the predominant form of alpha satellite is a 2.7-kilobase-pair higher-order repeat unit consisting of 16 alphoid monomers. We present the complete nucleotide sequence of the 16-monomer repeat, which is present in 500 to 1,000 copies per chromosome 17, as well as that of a less abundant 15-monomer repeat, also from chromosome 17. These repeat units were approximately 98% identical in sequence, differing by the exclusion of precisely 1 monomer from the 15-monomer repeat. Homologous unequal crossing-over is suggested as a probable mechanism by which the different repeat lengths on chromosome 17 were generated, and the putative site of such a recombination event is identified. The monomer organization of the chromosome 17 higher-order repeat unit is based, in part, on tandemly repeated pentamers. A similar pentameric suborganization has been previously demonstrated for alpha satellite of the human X chromosome. Despite the organizational similarities, substantial sequence divergence distinguishes these subsets. Hybridization experiments indicate that the chromosome 17 and X subsets are more similar to each other than to the subsets found on several other human chromosomes. We suggest that the chromosome 17 and X alpha satellite subsets may be related components of a larger alphoid subfamily which have evolved from a common ancestral repeat into the contemporary chromosome-specific subsets.

Chromosome aberrations in human lymphocytes for investigation of individual radiosensitivity; Chromosomenaberrationen in peripheren Lymphozyten zur Untersuchung der individuellen Strahlenempfindlichkeit

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Zitzelsberger, H. [LMU Muenchen (Germany). Strahlenbiologisches Inst.; Bauchinger, M. [GSF - Forschungszentrum fuer Umwelt und Gesundheit Oberschleissheim (Germany). Inst. fuer Strahlenbiologie

2000-07-01

Stable translocations and insertions which are not selected against during cell proliferation can be reliably scored by use of fluorescence in situ hybridisation (FISH) which allows painting of selected chromosomes along their entire length. This temporal persistence makes them particulary valuable for quantifying post human radiation exposures ('biodosimetry'). A disadvantage of this approach is that for routine use only a partial genome analysis can be performed which is mostly based on triple combinations of DNA probes for particular chromosomes. Translocation frequencies from partial genome analysis are often scaled-up to equal the full genome. Basic assumptions for such scaling are, that double strand breaks leading to translocations must be distributed randomly throughout the genome and no preferential interaction between particular pairs of chromosomes occurs. Thus, the probability of a particular chromosome being involved in an exchange is proportional to its DNA content. However, this is not always supported by experimental findings and may thus indicate a differential radiosensitivity of particular chromosomes. Translocation measurements in peripheral blood of different healthy donors irradiated in vitro with the same dose revealed also some evidence for the existence of interindividual differences in radiosensitivity. Similar findings have been already demonstrated after therapeutic irradiation of tumour patients. Consequences thereof may result for long-term retrospective biodosimetry. In order to provide reliable estimates of an individual's exposure to ionising radiation, the extent, distribution and dose-dependence of the observed variability has to be carefully examined in larger groups of persons and larger sets of calibration data. (orig.) [German] Durch die Anfaerbung kompletter Chromosomen mit Hilfe der Fluoreszenz-in-situ Hybridisierung (FISH) lassen sich die waehrend der Zellproliferation als stabil angesehenen Translokationen

Chromosomal mosaicism in human preimplantation embryos: a systematic review.

NARCIS (Netherlands)

Echten-Arends, J. van; Mastenbroek, S.; Sikkema-Raddatz, B.; Korevaar, J.C.; Heineman, M.J.; Veen, F. van der; Repping, S.

2011-01-01

BACKGROUND: Although chromosomal mosaicism in human preimplantation embryos has been described for almost two decades, its exact prevalence is still unknown. The prevalence of mosaicism is important in the context of preimplantation genetic screening in which the chromosomal status of an embryo is

Chromosomal mosaicism in human preimplantation embryos : a systematic review

NARCIS (Netherlands)

van Echten-Arends, Jannie; Mastenbroek, Sebastiaan; Sikkema-Raddatz, Birgit; Korevaar, Johanna C.; Heineman, Maas Jan; van der Veen, Fulco; Repping, Sjoerd

2011-01-01

BACKGROUND: Although chromosomal mosaicism in human preimplantation embryos has been described for almost two decades, its exact prevalence is still unknown. The prevalence of mosaicism is important in the context of preimplantation genetic screening in which the chromosomal status of an embryo is

Noninvolvement of the X chromosome in radiation-induced chromosome translocations in the human lymphoblastoid cell line TK6

International Nuclear Information System (INIS)

Jordan, R.; Schwartz, J.L.

1994-01-01

Fluorescence in situ hybridization procedures were used to examine the influence of chromosome locus on the frequency and type of chromosome aberrations induced by 60 Co γ rays in the human lymphoblastoid cell line TK6. Aberrations involving the X chromosome were compared to those involving the similarly sized autosome chromosome 7. When corrected for DNA content, acentric fragments were induced with equal frequency in the X and 7 chromosomes. Dose-dependent increases in chromosomal interchanges involving chromosome 7 were noted, and the frequencies of balanced translocations and dicentrics produced were approximately equal. Chromosome interchanges involving the X chromosome were rare and showed no apparent dose dependence. Thus, while chromosomes 7 and X are equally sensitive to the induction of chromosome breaks, the X chromosome is much less likely to interact with autosomes than chromosome 7. The noninvolvement of the X chromosome in translocations with autosomes may reflect a more peripheral and separate location for the X chromosome in the mammalian nucleus. 20 refs., 2 figs., 1 tab

The complete sequence of human chromosome 5

Energy Technology Data Exchange (ETDEWEB)

Schmutz, Jeremy; Martin, Joel; Terry, Astrid; Couronne, Olivier; Grimwood, Jane; Lowry, State; Gordon, Laurie A.; Scott, Duncan; Xie, Gary; Huang, Wayne; Hellsten, Uffe; Tran-Gyamfi, Mary; She, Xinwei; Prabhakar, Shyam; Aerts, Andrea; Altherr, Michael; Bajorek, Eva; Black, Stacey; Branscomb, Elbert; Caoile, Chenier; Challacombe, Jean F.; Chan, Yee Man; Denys, Mirian; Detter, Chris; Escobar, Julio; Flowers, Dave; Fotopulos, Dea; Glavina, Tijana; Gomez, Maria; Gonzales, Eidelyn; Goodstenin, David; Grigoriev, Igor; Groza, Matthew; Hammon, Nancy; Hawkins, Trevor; Haydu, Lauren; Israni, Sanjay; Jett, Jamie; Kadner, Kristen; Kimbal, Heather; Kobayashi, Arthur; Lopez, Frederick; Lou, Yunian; Martinez, Diego; Medina, Catherine; Morgan, Jenna; Nandkeshwar, Richard; Noonan, James P.; Pitluck, Sam; Pollard, Martin; Predki, Paul; Priest, James; Ramirez, Lucia; Rash, Sam; Retterer, James; Rodriguez, Alex; Rogers, Stephanie; Salamov, Asaf; Salazar, Angelica; Thayer, Nina; Tice, Hope; Tsai, Ming; Ustaszewska, Anna; Vo, Nu; Wheeler, Jeremy; Wu, Kevin; Yang, Joan; Dickson, Mark; Cheng, Jan-Fang; Eichler, Evan E.; Olsen, Anne; Pennacchio, Len A.; Rokhsar, Daniel S.; Richardson, Paul; Lucas, Susan M.; Myers, Richard M.; Rubin, Edward M.

2004-04-15

Chromosome 5 is one of the largest human chromosomes yet has one of the lowest gene densities. This is partially explained by numerous gene-poor regions that display a remarkable degree of noncoding and syntenic conservation with non-mammalian vertebrates, suggesting they are functionally constrained. In total, we compiled 177.7 million base pairs of highly accurate finished sequence containing 923 manually curated protein-encoding genes including the protocadherin and interleukin gene families and the first complete versions of each of the large chromosome 5 specific internal duplications. These duplications are very recent evolutionary events and play a likely mechanistic role, since deletions of these regions are the cause of debilitating disorders including spinal muscular atrophy (SMA).

Structure and chromosomal localization of the human lymphotoxin gene

International Nuclear Information System (INIS)

Nedwin, G.E.; Jarrett-Nedwin, J.; Smith, D.H.; Naylor, S.L.; Sakaguchi, A.Y.; Goeddel, D.V.; Gray, P.W.

1987-01-01

The authors have isolated, sequenced, and determined the chromosomal localization of the gene encoding human lymphotoxin (LT). The single copy gene was isolated from a human genomic library using a /sup 32/P-labeled 116 bp synthetic DNA fragment whose sequence was based on the NH/sub 2/-terminal amino acid sequence of LT. The gene spans 3 kb of DNA and is interrupted by three intervening sequences. The LT gene is located on human chromosome 6, as determined by Southern blot analysis of human-murine hybrid DNA. Putative transcriptional control regions and areas of homology with the promoters of interferon and other genes are identified

Cloning and comparative mapping of a human chromosome 4-specific alpha satellite DNA sequence

Energy Technology Data Exchange (ETDEWEB)

D' Aiuto, L.; Marzella, R.; Archidiacono, N.; Rocchi, M. (Universita di Bari (Italy)); Antonacci, R. (Instituto Anatomia Umana Normale, Modena (Italy))

1993-11-01

The authors have isolated and characterized two human alphoid DNA clones: p4n1/4 and pZ4.1. Clone p4n1/4 identifies specifically the centromeric region of chromosome 4; pZ4.1 recognizes a subset of alphoid DNA shared by chromosomes 4 and 9. The specificity was determined using fluorescence in situ hybridization experiments on metaphase spreads and Southern blotting analysis of human-hamster somatic cell hybrids. The genomic organization of both subsets was also investigated. Comparative mapping on chimpanzee and gorilla chromosomes was performed. p4n1/4 hybridizes to chimpanzee chromosomes 11 and 13, homologs of human chromosomes 9 and 2q, respectively. On gorilla metaphase spreads, p4n1/4 hybridizes exclusively to the centromeric region of chromosome 19, partially homologous to human chromosome 17. No hybridization signal was detected on chromosome 3 of both chimpanzee and gorilla, in both species homolog of human chromosome 4. Identical comparative mapping results were obtained using pZ4.1 probe, although the latter recognizes an alphoid subset distinct from the one recognized by p4n1/4. The implications of these results in the evolution of centromeric regions of primate chromosomes are discussed. 33 refs., 4 figs.

Cell-autonomous correction of ring chromosomes in human induced pluripotent stem cells

Science.gov (United States)

Bershteyn, Marina; Hayashi, Yohei; Desachy, Guillaume; Hsiao, Edward C.; Sami, Salma; Tsang, Kathryn M.; Weiss, Lauren A.; Kriegstein, Arnold R.; Yamanaka, Shinya; Wynshaw-Boris, Anthony

2014-03-01

Ring chromosomes are structural aberrations commonly associated with birth defects, mental disabilities and growth retardation. Rings form after fusion of the long and short arms of a chromosome, and are sometimes associated with large terminal deletions. Owing to the severity of these large aberrations that can affect multiple contiguous genes, no possible therapeutic strategies for ring chromosome disorders have been proposed. During cell division, ring chromosomes can exhibit unstable behaviour leading to continuous production of aneuploid progeny with low viability and high cellular death rate. The overall consequences of this chromosomal instability have been largely unexplored in experimental model systems. Here we generated human induced pluripotent stem cells (iPSCs) from patient fibroblasts containing ring chromosomes with large deletions and found that reprogrammed cells lost the abnormal chromosome and duplicated the wild-type homologue through the compensatory uniparental disomy (UPD) mechanism. The karyotypically normal iPSCs with isodisomy for the corrected chromosome outgrew co-existing aneuploid populations, enabling rapid and efficient isolation of patient-derived iPSCs devoid of the original chromosomal aberration. Our results suggest a fundamentally different function for cellular reprogramming as a means of `chromosome therapy' to reverse combined loss-of-function across many genes in cells with large-scale aberrations involving ring structures. In addition, our work provides an experimentally tractable human cellular system for studying mechanisms of chromosomal number control, which is of critical relevance to human development and disease.

Inter-chromosomal variation in the pattern of human population genetic structure

Directory of Open Access Journals (Sweden)

Baye Tesfaye M

2011-05-01

Full Text Available Abstract Emerging technologies now make it possible to genotype hundreds of thousands of genetic variations in individuals, across the genome. The study of loci at finer scales will facilitate the understanding of genetic variation at genomic and geographic levels. We examined global and chromosomal variations across HapMap populations using 3.7 million single nucleotide polymorphisms to search for the most stratified genomic regions of human populations and linked these regions to ontological annotation and functional network analysis. To achieve this, we used five complementary statistical and genetic network procedures: principal component (PC, cluster, discriminant, fixation index (FST and network/pathway analyses. At the global level, the first two PC scores were sufficient to account for major population structure; however, chromosomal level analysis detected subtle forms of population structure within continental populations, and as many as 31 PCs were required to classify individuals into homogeneous groups. Using recommended population ancestry differentiation measures, a total of 126 regions of the genome were catalogued. Gene ontology and networks analyses revealed that these regions included the genes encoding oculocutaneous albinism II (OCA2, hect domain and RLD 2 (HERC2, ectodysplasin A receptor (EDAR and solute carrier family 45, member 2 (SLC45A2. These genes are associated with melanin production, which is involved in the development of skin and hair colour, skin cancer and eye pigmentation. We also identified the genes encoding interferon-γ (IFNG and death-associated protein kinase 1 (DAPK1, which are associated with cell death, inflammatory and immunological diseases. An in-depth understanding of these genomic regions may help to explain variations in adaptation to different environments. Our approach offers a comprehensive strategy for analysing chromosome-based population structure and differentiation, and demonstrates the

Cytogenetic and molecular studies on a recombinant human X chromosome: implications for the spreading of X chromosome inactivation

International Nuclear Information System (INIS)

Mohandas, T.; Geller, R.L.; Yen, P.H.; Rosendorff, J.; Bernstein, R.; Yoshida, A.; Shapiro, L.J.

1987-01-01

A pericentric inversion of human X chromosome and a recombinant X chromosome [rec(X)] derived from crossing-over within the inversion was identified in a family. The rec(X) had a duplication of the segment Xq26.3 → Xqter and a deletion of Xp22.3 → Xpter and was interpreted to be Xqter → Xq26.3::Xp22.3 → Xqter. To characterize the rec(X) chromosome, dosage blots were done on genomic DNA from carriers of this rearranged X chromosome using a number of X chromosome probes. Results showed that anonymous sequences from the distal end of the long arm to which probes 4D8, Hx120A, DX13, and St14 bind as well as the locus for glucose-6-phosphate dehydrogenase (G6PD) wee duplicated on the rec(X). Mouse-human cell hybrids were constructed that retained the rec(X) in the active or inactive state. Analyses of these hybrid clones for markers from the distal short arm of the X chromosome showed that the rec(X) retained the loci for steroid sulfatase (STS) and the cell surface antigen 12E7 (MIC2); but not the pseudoautosomal sequence 113D. These molecular studies confirm that the rec(X) is a duplication-deficiency chromosome as expected. In the inactive state in cell hybrids, STS and MIC2 (which usually escape X chromosome inactivation) were expressed from the rec(X), whereas G6PD was not. Therefore, in the rec(X) X chromosome inactivation has spread through STS and MIC2 leaving these loci unaffected and has inactivated G6PD in the absence of an inactivation center in the q26.3 → qter region of the human X chromosome. The mechanism of spreading of inactivation appears to operate in a sequence-specific fashion. Alternatively, STS and MIC2 may have undergone inactivation initially but could not be maintained in an inactive state

Assignment of adenosine deaminase complexing protein (ADCP) gene(s) to human chromosome 2 in rodent-human somatic cell hybrids.

Science.gov (United States)

Herbschleb-Voogt, E; Grzeschik, K H; Pearson, P L; Meera Khan, P

1981-01-01

The experiments reported in this paper indicate that the expression of human adenosine deaminase complexing protein (ADCP) in the human-rodent somatic cell hybrids is influenced by the state of confluency of the cells and the background rodent genome. Thus, the complement of the L-cell derived A9 or B82 mouse parent apparently prevents the expression of human ADCP in the interspecific somatic cell hybrids. In the a3, E36, or RAG hybrids the human ADCP expression was not prevented by the rodent genome and was found to be proportional to the degree of confluency of the cell in the culture as in the case of primary human fibroblasts. An analysis of human chromosomes, chromosome specific enzyme markers, and ADCP in a panel of rodent-human somatic cell hybrids optimally maintained and harvested at full confluency has shown that the expression of human ADCP in the mouse (RAG)-human as well as in the hamster (E36 or a3)-human hybrids is determined by a gene(s) in human chromosome 2 and that neither chromosome 6 nor any other of the chromosomes of man carry any gene(s) involved in the formation of human ADCP at least in the Chinese hamster-human hybrids. A series of rodent-human hybrid clones exhibiting a mitotic separation of IDH1 and MDH1 indicated that ADCP is most probably situated between corresponding loci in human chromosome 2.

Non-random distribution of instability-associated chromosomal rearrangement breakpoints in human lymphoblastoid cells

International Nuclear Information System (INIS)

Moore, Stephen R.; Papworth, David; Grosovsky, Andrew J.

2006-01-01

Genomic instability is observed in tumors and in a large fraction of the progeny surviving irradiation. One of the best-characterized phenotypic manifestations of genomic instability is delayed chromosome aberrations. Our working hypothesis for the current study was that if genomic instability is in part attributable to cis mechanisms, we should observe a non-random distribution of chromosomes or sites involved in instability-associated rearrangements, regardless of radiation quality, dose, or trans factor expression. We report here the karyotypic examination of 296 instability-associated chromosomal rearrangement breaksites (IACRB) from 118 unstable TK6 human B lymphoblast, and isogenic derivative, clones. When we tested whether IACRB were distributed across the chromosomes based on target size, a significant non-random distribution was evident (p < 0.00001), and three IACRB hotspots (chromosomes 11, 12, and 22) and one IACRB coldspot (chromosome 2) were identified. Statistical analysis at the chromosomal band-level identified four IACRB hotspots accounting for 20% of all instability-associated breaks, two of which account for over 14% of all IACRB. Further, analysis of independent clones provided evidence within 14 individual clones of IACRB clustering at the chromosomal band level, suggesting a predisposition for further breaks after an initial break at some chromosomal bands. All of these events, independently, or when taken together, were highly unlikely to have occurred by chance (p < 0.000001). These IACRB band-level cluster hotspots were observed independent of radiation quality, dose, or cellular p53 status. The non-random distribution of instability-associated chromosomal rearrangements described here significantly differs from the distribution that was observed in a first-division post-irradiation metaphase analysis (p = 0.0004). Taken together, these results suggest that genomic instability may be in part driven by chromosomal cis mechanisms

Progress towards construction of a total restriction fragment map of a human chromosome.

NARCIS (Netherlands)

H. Vissing; F.G. Grosveld (Frank); E. Solomon; G. Moore; N. Lench; N. Shennan; R. Williamson

1987-01-01

textabstractWe present an approach to the construction of an overlapping restriction fragment map of a single human chromosome. A genomic cosmid library genome was constructed from a mouse-human hybrid cell line containing chromosome 17 as its only human genetic component. Cosmids containing human

Hexavalent chromium induces chromosome instability in human urothelial cells

Energy Technology Data Exchange (ETDEWEB)

Wise, Sandra S. [Wise Laboratory of Environmental and Genetic Toxicology, Maine Center for Toxicology and Environmental Health, Department of Applied Medical Science, University of Southern Maine, Science Building, 96 Falmouth Street, Portland, ME 04103 (United States); Holmes, Amie L. [Wise Laboratory of Environmental and Genetic Toxicology, Maine Center for Toxicology and Environmental Health, Department of Applied Medical Science, University of Southern Maine, Science Building, 96 Falmouth Street, Portland, ME 04103 (United States); Department of Radiation Oncology, Dana Farber Cancer Institute, 450 Brookline Ave., Boston, MA 02215 (United States); Liou, Louis [Department of Pathology, Boston University School of Medicine, 670 Albany St., Boston, MA 02118 (United States); Adam, Rosalyn M. [Department of Surgery, Harvard Medical School, Boston, MA 02115 (United States); Wise, John Pierce Sr., E-mail: john.wise@louisville.edu [Wise Laboratory of Environmental and Genetic Toxicology, Maine Center for Toxicology and Environmental Health, Department of Applied Medical Science, University of Southern Maine, Science Building, 96 Falmouth Street, Portland, ME 04103 (United States)

2016-04-01

Numerous metals are well-known human bladder carcinogens. Despite the significant occupational and public health concern of metals and bladder cancer, the carcinogenic mechanisms remain largely unknown. Chromium, in particular, is a metal of concern as incidences of bladder cancer have been found elevated in chromate workers, and there is an increasing concern for patients with metal hip implants. However, the impact of hexavalent chromium (Cr(VI)) on bladder cells has not been studied. We compared chromate toxicity in two bladder cell lines; primary human urothelial cells and hTERT-immortalized human urothelial cells. Cr(VI) induced a concentration- and time-dependent increase in chromosome damage in both cell lines, with the hTERT-immortalized cells exhibiting more chromosome damage than the primary cells. Chronic exposure to Cr(VI) also induced a concentration-dependent increase in aneuploid metaphases in both cell lines which was not observed after a 24 h exposure. Aneuploidy induction was higher in the hTERT-immortalized cells. When we correct for uptake, Cr(VI) induces a similar amount of chromosome damage and aneuploidy suggesting that the differences in Cr(VI) sensitivity between the two cells lines were due to differences in uptake. The increase in chromosome instability after chronic chromate treatment suggests this may be a mechanism for chromate-induced bladder cancer, specifically, and may be a mechanism for metal-induced bladder cancer, in general. - Highlights: • Hexavalent chromium is genotoxic to human urothelial cells. • Hexavalent chromium induces aneuploidy in human urothelial cells. • hTERT-immortalized human urothelial cells model the effects seen in primary urothelial cells. • Hexavalent chromium has a strong likelihood of being carcinogenic for bladder tissue.

Characterization of apparently balanced chromosomal rearrangements from the developmental genome anatomy project.

Science.gov (United States)

Higgins, Anne W; Alkuraya, Fowzan S; Bosco, Amy F; Brown, Kerry K; Bruns, Gail A P; Donovan, Diana J; Eisenman, Robert; Fan, Yanli; Farra, Chantal G; Ferguson, Heather L; Gusella, James F; Harris, David J; Herrick, Steven R; Kelly, Chantal; Kim, Hyung-Goo; Kishikawa, Shotaro; Korf, Bruce R; Kulkarni, Shashikant; Lally, Eric; Leach, Natalia T; Lemyre, Emma; Lewis, Janine; Ligon, Azra H; Lu, Weining; Maas, Richard L; MacDonald, Marcy E; Moore, Steven D P; Peters, Roxanna E; Quade, Bradley J; Quintero-Rivera, Fabiola; Saadi, Irfan; Shen, Yiping; Shendure, Jay; Williamson, Robin E; Morton, Cynthia C

2008-03-01

Apparently balanced chromosomal rearrangements in individuals with major congenital anomalies represent natural experiments of gene disruption and dysregulation. These individuals can be studied to identify novel genes critical in human development and to annotate further the function of known genes. Identification and characterization of these genes is the goal of the Developmental Genome Anatomy Project (DGAP). DGAP is a multidisciplinary effort that leverages the recent advances resulting from the Human Genome Project to increase our understanding of birth defects and the process of human development. Clinically significant phenotypes of individuals enrolled in DGAP are varied and, in most cases, involve multiple organ systems. Study of these individuals' chromosomal rearrangements has resulted in the mapping of 77 breakpoints from 40 chromosomal rearrangements by FISH with BACs and fosmids, array CGH, Southern-blot hybridization, MLPA, RT-PCR, and suppression PCR. Eighteen chromosomal breakpoints have been cloned and sequenced. Unsuspected genomic imbalances and cryptic rearrangements were detected, but less frequently than has been reported previously. Chromosomal rearrangements, both balanced and unbalanced, in individuals with multiple congenital anomalies continue to be a valuable resource for gene discovery and annotation.

Report of the Fourth international workshop on human chromosome 18 mapping 1996

International Nuclear Information System (INIS)

Silverman, G.A.; Overhauser, J.; Gerken, S.; Aburomia, R.; O'Connell, P.; Krauter, K.S.; Detera-Wadleigh, S.D.; Yoshikawa, T.; Collins, A.R.; Geurts van Kessel, A.

1996-01-01

The fourth international workshop on human chromosome 18 mapping was held in Boston, Massachusetts, USA on October 7-9, 1996. The workshop was attended by 34 participants from 7 countries. The goals of the workshop were to (1) generate integrated genetic and physical maps, (2) update the transcriptional map, (3) assess the syntenic relationships between human chromosome 18 and the mouse genome, and (4) establish a chromosome 18 web site

Human chromosome 9 can complement UV sensitivity of xeroderma pigmentosum group A cells

International Nuclear Information System (INIS)

Ishizaki, Kanji; Sasaki, Masao S.; Ikenaga, Mituo; Nakamura, Yusuke

1990-01-01

A single human chromosome derived from normal human fibroblasts and tagged with the G418 resistance gene was transferred into SV40-transformed xeroderma pigmentosum group A (XP-A) cells via microcell fusion. When chromosome 1 or 12 was transferred, UV sensitivity of microcell hybrid cells was not changed. By contrast, after transferring chromosome 9,7 of 11 reipient clones were as UV-resistant as normal human cells. Four other clones were still as UV-sensitive as the parental XP-A cells. Southern hybridization analysis using a polymorphic probe, pEKZ19.3, which is homologous to a sequence of the D9S17 locus on chromosome 9, has confirmed that at least a part of normal human chromosome 9 was transferred into the recipient clones. However, amounts iof UV-induced unscheduled DNA synthesis in the UV-resistant clones were only one-third of those in normal human cells. These results indicate that a gene on chromosome 9 can confer complementation of high UV sensitivity of XP-A cells although it is still possible that 2 or more genes might be involved in the defective-repair phenotypes of XP-A. (author). 20 refs.; 3 figs.; 1 tab

Comparative mapping of DNA markers from the familial Alzheimer disease and Down syndrome regions of human chromosome 21 to mouse chromosomes 16 and 17

Energy Technology Data Exchange (ETDEWEB)

Cheng, S.V.; Nadeau, J.H.; Tanzi, R.E.; Watkins, P.C.; Jagadesh, J.; Taylor, B.A.; Haines, J.L.; Sacchi, N.; Gusella, J.F. (Harvard Medical School, Boston, MA (USA))

1988-08-01

Mouse trisomy 16 has been proposed as an animal model of Down syndrome (DS), since this chromosome contains homologues of several loci from the q22 band of human chromosome 21. The recent mapping of the defect causing familial Alzheimer disease (FAD) and the locus encoding the Alzheimer amyloid {beta} precursor protein (APP) to human chromosome 21 has prompted a more detailed examination of the extent of conservation of this linkage group between the two species. Using anonymous DNA probes and cloned genes from human chromosome 21 in a combination of recombinant inbred and interspecific mouse backcross analyses, the authors have established that the linkage group shared by mouse chromosome 16 includes not only the critical DS region of human chromosome 21 but also the APP gene and FAD-linked markers. Extending from the anonymous DNA locus D21S52 to ETS2, the linkage map of six loci spans 39% recombination in man but only 6.4% recombination in the mouse. A break in synteny occurs distal to ETS2, with the homologue of the human marker D21S56 mapping to mouse chromosome 17. Conservation of the linkage relationships of markers in the FAD region suggests that the murine homologue of the FAD locus probably maps to chromosome 16 and that detailed comparison of the corresponding region in both species could facilitate identification of the primary defect in this disorder. The break in synteny between the terminal portion of human chromosome 21 and mouse chromosome 16 indicates, however, that mouse trisomy 16 may not represent a complete model of DS.

Comparative mapping of DNA markers from the familial Alzheimer disease and Down syndrome regions of human chromosome 21 to mouse chromosomes 16 and 17

International Nuclear Information System (INIS)

Cheng, S.V.; Nadeau, J.H.; Tanzi, R.E.; Watkins, P.C.; Jagadesh, J.; Taylor, B.A.; Haines, J.L.; Sacchi, N.; Gusella, J.F.

1988-01-01

Mouse trisomy 16 has been proposed as an animal model of Down syndrome (DS), since this chromosome contains homologues of several loci from the q22 band of human chromosome 21. The recent mapping of the defect causing familial Alzheimer disease (FAD) and the locus encoding the Alzheimer amyloid β precursor protein (APP) to human chromosome 21 has prompted a more detailed examination of the extent of conservation of this linkage group between the two species. Using anonymous DNA probes and cloned genes from human chromosome 21 in a combination of recombinant inbred and interspecific mouse backcross analyses, the authors have established that the linkage group shared by mouse chromosome 16 includes not only the critical DS region of human chromosome 21 but also the APP gene and FAD-linked markers. Extending from the anonymous DNA locus D21S52 to ETS2, the linkage map of six loci spans 39% recombination in man but only 6.4% recombination in the mouse. A break in synteny occurs distal to ETS2, with the homologue of the human marker D21S56 mapping to mouse chromosome 17. Conservation of the linkage relationships of markers in the FAD region suggests that the murine homologue of the FAD locus probably maps to chromosome 16 and that detailed comparison of the corresponding region in both species could facilitate identification of the primary defect in this disorder. The break in synteny between the terminal portion of human chromosome 21 and mouse chromosome 16 indicates, however, that mouse trisomy 16 may not represent a complete model of DS

Induction of chromosome aberrations and mitotic arrest by cytomegalovirus in human cells

International Nuclear Information System (INIS)

AbuBakar, S.; Au, W.W.; Legator, M.S.; Albrecht, T.

1988-01-01

Human cytomegalovirus (CMV) is potentially an effective but often overlooked genotoxic agent in humans. We report here evidence that indicates that infection by CMV can induce chromosome alterations and mitotic inhibition. The frequency of chromosome aberrations induced was dependent on the input multiplicity of infection (m.o.i.) for human lung fibroblasts (LU), but not for human peripheral blood lymphocytes (PBLs) when both cell types were infected at the GO phase of the cell cycle. The aberrations induced by CMV were mostly chromatid breaks and chromosome pulverizations that resembled prematurely condensed S-phase chromatin. Pulverized chromosomes were not observed in LU cells infected with virus stocks that had been rendered nonlytic by UV-irradiation at 24,000 ergs/mm2 or from infection of human lymphocytes. In LU cells infected with UV-irradiated CMV, the frequency of aberrations induced was inversely dependent on the extent of the exposure of the CMV stock to the UV-light. In permissive CMV infection of proliferating LU cells at 24 hr after subculture, a high percentage (greater than 40%) of the metaphase cells were arrested at their first metaphase and displayed severely condensed chromosomes when harvested 48 hr later. A significant increase (p less than 0.05) in the chromosome aberration frequency was also observed. Our study shows that CMV infection is genotoxic to host cells. The types and extent of damage are dependent on the viral genome expression and on the cell cycle stage of the cells at the time of infection. The possible mechanisms for induction of chromosome damage by CMV are discussed

Screening human populations for chromosome damage. Progress report, March 1982-November 1982

International Nuclear Information System (INIS)

Norman, A.

1982-01-01

The micronuclear counts in 73 relatively young and healthy patients obtained in previous studies were examined. The natural logarithm of the micronuclear counts (LMNC) was approximately normally distributed so we have tested the effects of age, sex, and medical x-ray exposure on the counts. The results show a clear dependence of micronuclear counts on age, and demonstrate that studies of chromosome damage in radiation workers or in other populations exposed to radiation may be misinterpreted if the effects of age and medical x-ray examinations are not controlled. The results also show that the variability in LNMC among the individuals examined cannot be accounted for totally by the factors of age, sex, or medical x-rays. There are at least two other important sources of variation: counting statistics and degree of lymphocyte proliferation. A single set of harlequin stained cells may be sufficient for estimating micronuclear yields, the degree of lymphocyte proliferation, and possibly the frequency of chromosome aberrations. These results point to the usefulness of the micronucleus assay for screening human populations for chromosome damage

Human Y chromosome copy number variation in the next generation sequencing era and beyond.

Science.gov (United States)

Massaia, Andrea; Xue, Yali

2017-05-01

The human Y chromosome provides a fertile ground for structural rearrangements owing to its haploidy and high content of repeated sequences. The methodologies used for copy number variation (CNV) studies have developed over the years. Low-throughput techniques based on direct observation of rearrangements were developed early on, and are still used, often to complement array-based or sequencing approaches which have limited power in regions with high repeat content and specifically in the presence of long, identical repeats, such as those found in human sex chromosomes. Some specific rearrangements have been investigated for decades; because of their effects on fertility, or their outstanding evolutionary features, the interest in these has not diminished. However, following the flourishing of large-scale genomics, several studies have investigated CNVs across the whole chromosome. These studies sometimes employ data generated within large genomic projects such as the DDD study or the 1000 Genomes Project, and often survey large samples of healthy individuals without any prior selection. Novel technologies based on sequencing long molecules and combinations of technologies, promise to stimulate the study of Y-CNVs in the immediate future.

Microarray Analysis of Copy Number Variants on the Human Y Chromosome Reveals Novel and Frequent Duplications Overrepresented in Specific Haplogroups.

Directory of Open Access Journals (Sweden)

Martin M Johansson

Full Text Available The human Y chromosome is almost always excluded from genome-wide investigations of copy number variants (CNVs due to its highly repetitive structure. This chromosome should not be forgotten, not only for its well-known relevance in male fertility, but also for its involvement in clinical phenotypes such as cancers, heart failure and sex specific effects on brain and behaviour.We analysed Y chromosome data from Affymetrix 6.0 SNP arrays and found that the signal intensities for most of 8179 SNP/CN probes in the male specific region (MSY discriminated between a male, background signals in a female and an isodicentric male containing a large deletion of the q-arm and a duplication of the p-arm of the Y chromosome. Therefore, this SNP/CN platform is suitable for identification of gain and loss of Y chromosome sequences. In a set of 1718 males, we found 25 different CNV patterns, many of which are novel. We confirmed some of these variants by PCR or qPCR. The total frequency of individuals with CNVs was 14.7%, including 9.5% with duplications, 4.5% with deletions and 0.7% exhibiting both. Hence, a novel observation is that the frequency of duplications was more than twice the frequency of deletions. Another striking result was that 10 of the 25 detected variants were significantly overrepresented in one or more haplogroups, demonstrating the importance to control for haplogroups in genome-wide investigations to avoid stratification. NO-M214(xM175 individuals presented the highest percentage (95% of CNVs. If they were not counted, 12.4% of the rest included CNVs, and the difference between duplications (8.9% and deletions (2.8% was even larger.Our results demonstrate that currently available genome-wide SNP platforms can be used to identify duplications and deletions in the human Y chromosome. Future association studies of the full spectrum of Y chromosome variants will demonstrate the potential involvement of gain or loss of Y chromosome sequence in

Combinations of chromosome transfer and genome editing for the development of cell/animal models of human disease and humanized animal models.

Science.gov (United States)

Uno, Narumi; Abe, Satoshi; Oshimura, Mitsuo; Kazuki, Yasuhiro

2018-02-01

Chromosome transfer technology, including chromosome modification, enables the introduction of Mb-sized or multiple genes to desired cells or animals. This technology has allowed innovative developments to be made for models of human disease and humanized animals, including Down syndrome model mice and humanized transchromosomic (Tc) immunoglobulin mice. Genome editing techniques are developing rapidly, and permit modifications such as gene knockout and knockin to be performed in various cell lines and animals. This review summarizes chromosome transfer-related technologies and the combined technologies of chromosome transfer and genome editing mainly for the production of cell/animal models of human disease and humanized animal models. Specifically, these include: (1) chromosome modification with genome editing in Chinese hamster ovary cells and mouse A9 cells for efficient transfer to desired cell types; (2) single-nucleotide polymorphism modification in humanized Tc mice with genome editing; and (3) generation of a disease model of Down syndrome-associated hematopoiesis abnormalities by the transfer of human chromosome 21 to normal human embryonic stem cells and the induction of mutation(s) in the endogenous gene(s) with genome editing. These combinations of chromosome transfer and genome editing open up new avenues for drug development and therapy as well as for basic research.

New insights into human nondisjunction of chromosome 21 in oocytes.

Directory of Open Access Journals (Sweden)

Tiffany Renee Oliver

2008-03-01

Full Text Available Nondisjunction of chromosome 21 is the leading cause of Down syndrome. Two risk factors for maternal nondisjunction of chromosome 21 are increased maternal age and altered recombination. In order to provide further insight on mechanisms underlying nondisjunction, we examined the association between these two well established risk factors for chromosome 21 nondisjunction. In our approach, short tandem repeat markers along chromosome 21 were genotyped in DNA collected from individuals with free trisomy 21 and their parents. This information was used to determine the origin of the nondisjunction error and the maternal recombination profile. We analyzed 615 maternal meiosis I and 253 maternal meiosis II cases stratified by maternal age. The examination of meiosis II errors, the first of its type, suggests that the presence of a single exchange within the pericentromeric region of 21q interacts with maternal age-related risk factors. This observation could be explained in two general ways: 1 a pericentromeric exchange initiates or exacerbates the susceptibility to maternal age risk factors or 2 a pericentromeric exchange protects the bivalent against age-related risk factors allowing proper segregation of homologues at meiosis I, but not segregation of sisters at meiosis II. In contrast, analysis of maternal meiosis I errors indicates that a single telomeric exchange imposes the same risk for nondisjunction, irrespective of the age of the oocyte. Our results emphasize the fact that human nondisjunction is a multifactorial trait that must be dissected into its component parts to identify specific associated risk factors.

NEUROD2 and NEUROD3 genes map to human chromosomes 17q12 and 5q23-q31 and mouse chromosomes 11 and 13, respectively

Energy Technology Data Exchange (ETDEWEB)

Tamimi, R.M.; Montgomery-Dyer, K.; Tapscott, S.J. [Fred Hutchinson Cancer Research Center, Seattle, WA (United States)] [and others

1997-03-01

NEUROD2 and NEUROD3 are transcription factors involved in neurogenesis that are related to the basic helix-loop-helix protein NEUROD. NEUROD2 maps to human chromosome 17q12 and mouse chromosome 11. NEUROD3 maps to human chromosome 5q23-q31 and mouse chromosome 13. 16 refs., 2 figs.

Replication Banding Patterns in Human Chromosomes Detected Using 5-ethynyl-2'-deoxyuridine Incorporation

International Nuclear Information System (INIS)

Hoshi, Osamu; Ushiki, Tatsuo

2011-01-01

A novel technique using the incorporation of 5-ethynyl-2'-deoxyuridine (EdU) into replicating DNA is described for the analysis of replicating banding patterns of human metaphase chromosomes. Human lymphocytes were synchronized with excess thymidine and treated with EdU during the late S phase of the cell cycle. The incorporated EdU was then detected in metaphase chromosomes using Alexa Fluor® 488 azides, through the 1,3-dipolar cycloaddition reaction of organic azides with the terminal acetylene group of EdU. Chromosomes with incorporated EdU showed a banding pattern similar to G-banding of normal human chromosomes. Imaging by atomic force microscopy (AFM) in liquid conditions showed that the structure of the chromosomes was well preserved even after EdU treatment. Comparison between fluorescence microscopy and AFM images of the same chromosome 1 indicated the presence of ridges and grooves in the chromatid arm, features that have been previously reported in relation to G-banding. These results suggest an intimate relationship between EdU-induced replication bands and G- or R-bands in human chromosomes. This technique is thus useful for analyzing the structure of chromosomes in relation to their banding patterns following DNA replication in the S phase

Chromosome segregation regulation in human zygotes: altered mitotic histone phosphorylation dynamics underlying centromeric targeting of the chromosomal passenger complex.

Science.gov (United States)

van de Werken, C; Avo Santos, M; Laven, J S E; Eleveld, C; Fauser, B C J M; Lens, S M A; Baart, E B

2015-10-01

Are the kinase feedback loops that regulate activation and centromeric targeting of the chromosomal passenger complex (CPC), functional during mitosis in human embryos? Investigation of the regulatory kinase pathways involved in centromeric CPC targeting revealed normal phosphorylation dynamics of histone H2A at T120 (H2ApT120) by Bub1 kinase and subsequent recruitment of Shugoshin, but phosphorylation of histone H3 at threonine 3 (H3pT3) by Haspin failed to show the expected centromeric enrichment on metaphase chromosomes in the zygote. Human cleavage stage embryos show high levels of chromosomal instability. What causes this high error rate is unknown, as mechanisms used to ensure proper chromosome segregation in mammalian embryos are poorly described. In this study, we investigated the pathways regulating CPC targeting to the inner centromere in human embryos. We characterized the distribution of the CPC in relation to activity of its two main centromeric targeting pathways: the Bub1-H2ApT120-Sgo-CPC and Haspin-H3pT3-CPC pathways. The study was conducted between May 2012 and March 2014 on human surplus embryos resulting from in vitro fertilization treatment and donated for research. In zygotes, nuclear envelope breakdown was monitored by time-lapse imaging to allow timed incubations with specific inhibitors to arrest at prometaphase and metaphase, and to interfere with Haspin and Aurora B/C kinase activity. Functionality of the targeting pathways was assessed through characterization of histone phosphorylation dynamics by immunofluorescent analysis, combined with gene expression by RT-qPCR and immunofluorescent localization of key pathway proteins. Immunofluorescent analysis of the CPC subunit Inner Centromere Protein revealed the pool of stably bound CPC proteins was not strictly confined to the inner centromere of prometaphase chromosomes in human zygotes, as observed in later stages of preimplantation development and somatic cells. Investigation of the

Molecular mechanism in the formation of a human ring chromosome 21

International Nuclear Information System (INIS)

Wong, C.; Kazazian, H.H. Jr.; Stetten, G.; Earnshaw, W.C.; Antonarakis, S.E.; Van Keuren, M.L.

1989-01-01

The authors have characterized the structural rearrangements of a chromosome 21 that led to the de novo formation of a human ring chromosome 21 [r(21)]. Molecular cloning and chromosomal localization of the DNA regions flanking the ring junction provide evidence for a long arm to long arm fusion in formation of the r(21). In addition, the centromere and proximal long arm region of a maternal chromosome 21 are duplicated in the r(21). Therefore, the mechanism in formation of the r(21) was complex involving two sequential chromosomal rearrangements. (i) Duplication of the centromere and long arm of one maternal chromosome 21 occurred forming a rearranged intermediate. (ii) Chromosomal breaks in both the proximal and telomeric long arm regions on opposite arms of this rearranged chromosome occurred with subsequent reunion producing the r(21)

Isolation and characterization of DNA probes from a flow-sorted human chromosome 8 library that detect restriction fragment length polymorphism (RFLP).

Science.gov (United States)

Wood, S; Starr, T V; Shukin, R J

1986-01-01

We have used a recombinant DNA library constructed from flow-sorted human chromosome 8 as a source of single-copy human probes. These probes have been screened for restriction fragment length polymorphism (RFLP) by hybridization to Southern transfers of genomic DNA from five unrelated individuals. We have detected six RFLPs distributed among four probes after screening 741 base pairs for restriction site variation. These RFLPs all behave as codominant Mendelian alleles. Two of the probes detect rare variants, while the other two detect RFLPs with PIC values of .36 and .16. Informative probes will be useful for the construction of a linkage map for chromosome 8 and for the localization of mutant alleles to this chromosome. Images Fig. 1 PMID:2879441

The DNA sequence and biology of human chromosome 19

Energy Technology Data Exchange (ETDEWEB)

Grimwood, J; Gordon, L A; Olsen, A; Terry, A; Schmutz, J; Lamerdin, J; Hellsten, U; Goodstein, D; Couronne, O; Tran-Gyamfi, M

2004-04-06

Chromosome 19 has the highest gene density of all human chromosomes, more than double the genome-wide average. The large clustered gene families, corresponding high GC content, CpG islands and density of repetitive DNA indicate a chromosome rich in biological and evolutionary significance. Here we describe 55.8 million base pairs of highly accurate finished sequence representing 99.9% of the euchromatin portion of the chromosome. Manual curation of gene loci reveals 1,461 protein-coding genes and 321 pseudogenes. Among these are genes directly implicated in Mendelian disorders, including familial hypercholesterolemia and insulin-resistant diabetes. Nearly one quarter of these genes belong to tandemly arranged families, encompassing more than 25% of the chromosome. Comparative analyses show a fascinating picture of conservation and divergence, revealing large blocks of gene orthology with rodents, scattered regions with more recent gene family expansions and deletions, and segments of coding and non-coding conservation with the distant fish species Takifugu.

Mouse Chromosome Engineering for Modeling Human Disease

OpenAIRE

van der Weyden, Louise; Bradley, Allan

2006-01-01

Chromosomal rearrangements occur frequently in humans and can be disease-associated or phenotypically neutral. Recent technological advances have led to the discovery of copy-number changes previously undetected by cytogenetic techniques. To understand the genetic consequences of such genomic changes, these mutations need to be modeled in experimentally tractable systems. The mouse is an excellent organism for this analysis because of its biological and genetic similarity to humans, and the e...

Cloning an expressed gene shared by the human sex chromosomes

International Nuclear Information System (INIS)

Darling, S.M.; Banting, G.S.; Pym, B.; Wolfe, J.; Goodfellow, P.N.

1986-01-01

The existence of genes shared by mammalian sex chromosomes has been predicted on both evolutionary and functional grounds. However, the only experimental evidence for such genes in humans is the cell-surface antigen encoded by loci on the X and Y chromosomes (MIC2X and MIC2Y, respectively), which is recognized by the monoclonal antibody 12E7. Using the bacteriophage λgt11 expression system in Escherichia coli and immunoscreening techniques, the authors have isolated a cDNA clone whose primary product is recognized by 12E7. Southern blot analysis using somatic cell hybrids containing only the human X or Y chromosomes shows that the sequences reacting with the cDNA clone are localized to the sex chromosomes. In addition, the clone hybridizes to DNAs isolated from mouse cells that have been transfected with human DNA and selected for 12E7 expression on the fluorescence-activated cell sorter. The authors conclude that the cDNA clone encodes the 12E7 antigen, which is the primary product of the MIC2 loci. The clone was used to explore sequence homology between MIC2X and MIC2Y; these loci are closely related, if not identical

Complementation of a DNA repair defect in xeroderma pigmentosum cells by transfer of human chromosome 9

International Nuclear Information System (INIS)

Kaur, G.P.; Athwal, R.S.

1989-01-01

Complementation of the repair defect in xeroderma pigmentosum cells of complementation group A was achieved by the transfer of human chromosome 9. A set of mouse-human hybrid cell lines, each containing a single Ecogpt-marked human chromosome, was used as a source of donor chromosomes. Chromosome transfer to XPTG-1 cells, a hypoxanthine/guanine phosphoribosyltransferase-deficient mutant of simian virus 40-transformed complementation group A cells, was achieved by microcell fusion and selection for Ecogpt. Chromosome-transfer clones of XPTG-1 cells, each containing a different human donor chromosome, were analyzed for complementation of sensitivity to UV irradiation. Among all the clones, increased levels of resistance to UV was observed only in clones containing chromosome 9. Since our recipient cell line XPTG-1 is hypoxanthine/guanine phosphoribosyltransferase deficient, cultivation of Ecogpt+ clones in medium containing 6-thioguanine permits selection of cells for loss of the marker and, by inference, transferred chromosome 9. Clones isolated for growth in 6-thioguanine, which have lost the Ecogpt-marked chromosome, exhibited a UV-sensitive phenotype, confirming the presence of the repair gene(s) for complementation group A on chromosome 9

Utilization of a cloned alphoid repeating sequence of human DNA in the study of polymorphism of chromosomal heterochromatin regions

International Nuclear Information System (INIS)

Kruminya, A.R.; Kroshkina, V.G.; Yurov, Yu.B.; Aleksandrov, I.A.; Mitkevich, S.P.; Gindilis, V.M.

1988-01-01

The chromosomal distribution of the cloned PHS05 fragment of human alphoid DNA was studied by in situ hybridization in 38 individuals. It was shown that this DNA fraction is primarily localized in the pericentric regions of practically all chromosomes of the set. Significant interchromosomal differences and a weakly expressed interindividual polymorphism were discovered in the copying ability of this class of repeating DNA sequences; associations were not found between the results of hybridization and the pattern of Q-polymorphism

The mapping of novel genes to human chromosome 19

Energy Technology Data Exchange (ETDEWEB)

Buenaventura, J.M. [Sarah Lawrence College, Bronxville, NY (United States)

1994-12-01

The principle goal of our laboratory is the discovery of new genes on human chromosome 19. One of the strategies to achieve this goal is through the use of cDNA clones known as {open_quotes}expressed sequence tags{close_quotes} (ESTs). ESTs, short segments of sequence from a cDNA clone that correspond to the mRNA, occur as unique regions in the genome and, therefore, can be used as markers for specific positions. In collaboration with researchers from Genethon in France, fifteen cDNA clones from a normalized human infant brain cDNA library were tested and determined to map to chromosome 19. A verification procedure is then followed to confirm assignment to chromosome 19. First, primers for each cDNA clone are developed and then amplified by polymerase chain reaction from genomic DNA. Next, a {sup 32}P-radiolabeled probe is made by polymerase chain reaction for each clone and then hybridized against filters containing an LLNL chromosome 19-specific cosmid library to find putative locations on the chromosome. The location is then verified by running a polymerase chain reactions from the positive cosmids. With the Browser database at LLNL, additional information about the positive cosmids can be found. Through use of the BLAST database at the National Library of Medicine, homologous sequences to the clones can be found. Among the fifteen cDNA clones received from Genethon, all have been amplified by polymerase chain reaction. Three have turned out as repetitive elements in the genome. Ten have been mapped to specific locations on chromosome 19. Putative locations have been found for the remaining two clones and thus verification testing will proceed.

Chromatin structure and ionizing-radiation-induced chromosome aberrations

International Nuclear Information System (INIS)

Muehlmann-Diaz, M.C.

1993-01-01

The possible influence of chromatic structure or activity on chromosomal radiosensitivity was studied. A cell line was isolated which contained some 10 5 copies of an amplified plasmid in a single large mosquito artificial chromosome (MAC). This chromosome was hypersensitive to DNase I. Its radiosensitivity was some three fold greater than normal mosquito chromosomes in the same cell. In cultured human cells irradiated during G 0 , the initial breakage frequency in chromosome 4, 19 and the euchromatic and heterochromatic portions of the Y chromosome were measured over a wide range of doses by inducing Premature Chromosome Condensation (PCC) immediately after irradiation with Cs-137 gamma rays. No evidence was seen that Y heterochromatin or large fragments of it remained unbroken. The only significant deviation from the expected initial breakage frequency per Gy per unit length of chromosome was that observed for the euchromatic portion of the Y chromosome, with breakage nearly twice that expected. The development of aberrations involving X and Y chromosomes at the first mitosis after irradation was also studied. Normal female cells sustained about twice the frequency of aberrations involving X chromosomes for a dose of 7.3 Gy than the corresponding male cells. Fibroblasts from individuals with supernumerary X chromosomes did not show any further increase in X aberrations for this dos. The frequency of aberrations involving the heterochromatic portion of the long arm of the Y chromosome was about what would be expected for a similar length of autosome, but the euchromatic portion of the Y was about 3 times more radiosensitive per unit length. 5-Azacytidine treatment of cultured human female fibroblasts or fibroblasts from a 49,XXXXY individual, reduced the methylation of cytosine residues in DNA, and resulted in an increased chromosomal radiosensitivity in general, but it did not increase the frequency of aberrations involving the X chromosomes

Radiation hybrids from human chromosome 3: A basis for the construction of region and specific sublibraries

International Nuclear Information System (INIS)

Atchison, L.; Cosmis, R.L.; Atchison, M.L.

1990-01-01

The authors are interested in identifying genes on human chromosome involved in disease processes. To date at least 20 different loci on this chromosome are implicated with various disease states. DNA libraries containing clones derived from a small chromosomal subregion implicated in a particular disease would greatly assist these studies. They have utilized the radiation hybrid (RH) technique to generate a series of somatic cell hybrids that contain small segments of human chromosome 3 as the only human genetic material. A Chinese hamster-human cell hybrid (Q314-2) containing only human chromosome 3 was used to prepare radiation hybrids. Cells were lethally X-irradiated with 6,000 rads and fused to Urd(??) Chinese hamster cells by PEG 1000 treatment. The majority of hybrids (>72%) analyzed retained portions of chromosome 3. The amount of chromosome 3 in each hybrid ranged from nearly all of the chromosome to very little. Currently these hybrids are being further characterized with single copy probes of known map location in order to isolate regions of chromosome 3 that contain specific disease locus. These reduced hybrids can then be used for the construction of region specific libraries and for the generation of new DNA probes from the specific region of interest

Statistical properties of nucleotides in human chromosomes 21 and 22

International Nuclear Information System (INIS)

Zhang Linxi; Sun Tingting

2005-01-01

In this paper the statistical properties of nucleotides in human chromosomes 21 and 22 are investigated. The n-tuple Zipf analysis with n = 3, 4, 5, 6, and 7 is used in our investigation. It is found that the most common n-tuples are those which consist only of adenine (A) and thymine (T), and the rarest n-tuples are those in which GC or CG pattern appears twice. With the n-tuples become more and more frequent, the double GC or CG pattern becomes a single GC or CG pattern. The percentage of four nucleotides in the rarest ten and the most common ten n-tuples are also considered in human chromosomes 21 and 22, and different behaviors are found in the percentage of four nucleotides. Frequency of appearance of n-tuple f(r) as a function of rank r is also examined. We find the n-tuple Zipf plot shows a power-law behavior for r n-1 and a rapid decrease for r > 4 n-1 . In order to explore the interior statistical properties of human chromosomes 21 and 22 in detail, we divide the chromosome sequence into some moving windows and we discuss the percentage of ξη (ξ, η = A, C, G, T) pair in those moving windows. In some particular regions, there are some obvious changes in the percentage of ξη pair, and there maybe exist functional differences. The normalized number of repeats N 0 (l) can be described by a power law: N 0 (l) ∼ l -μ . The distance distributions P 0 (S) between two nucleotides in human chromosomes 21 and 22 are also discussed. A two-order polynomial fit exists in those distance distributions: log P 0 (S) = a + bS + cS 2 , and it is quite different from the random sequence

Chromosomal Damage and Apoptosis in Exfoliated Buccal Cells from Individuals with Oral Cancer

Science.gov (United States)

Dórea, Lavínia Tércia Magalhães; Meireles, José Roberto Cardoso; Lessa, Júlia Paula Ramos; Oliveira, Márcio Campos; de Bragança Pereira, Carlos Alberto; Polpo de Campos, Adriano; Cerqueira, Eneida de Moraes Macílio

2012-01-01

This study aimed to investigate cytological abnormalities indicative of chromosome damage (micronuclei) and apoptosis (karyorrhexis, pyknosis, and condensed chromatin) in exfoliated cells from the buccal mucosa of patients with oral cancer and control subjects. The sample included twenty individuals with oral cancer and forty individuals with normal buccal mucosa. Material was collected from the cheek epithelium in areas with lesions and areas without abnormalities. A minimum of one thousand cells was analyzed. Micronuclei were found significantly more frequently in cells collected from lesions than in cells from normal areas, independent of the presence/absence of cancer (P < 0.0001). They were also significantly more frequent in smokers and in mouthwash users (P < 0.0001). Apoptosis occurred significantly less frequently in individuals with oral cancer (P < 0.0001). These results show that oral cancer is associated with higher frequency of chromosomal damage and suggest that apoptosis is compromised in the buccal cells of individuals with this kind of neoplasia. PMID:22315605

Transmission of chromosomal and instability via a chromosome irradiated with ionizing radiation

International Nuclear Information System (INIS)

Kodama, Seiji; Tanabe, Masateru; Shiraishi, Kazunori; Oshimura, Mitsuo

2010-01-01

We examined the stability of the transferred chromosome in 5 and 12 microcell hybrids including unirradiated human chromosomes 6 and 8, respectively, and 6 and 19 microcell hybrids including 4 Gy-irradiated human chromosomes 6 and 8, respectively. The transferred chromosome was structurally stable in most microcell hybrids transferred with the unirradiated chromosomes 6 and 8. In contrast, the 4 Gy-irradiated human chromosomes were unstable in 3 out of 6 hybrids (50%) with chromosome 6 and 3 out of 19 hybrids (16%) with chromosome 8, showing multiple aberrations in high frequencies (35∼98%). To know the cause of delayed chromosomal instability, intrachromosomal rearrangements of the human chromosome is investigated by subtelomere FISH in 17 microcell hybrids transferred with chromosomes 6 and 8. We found frequent intrachromosomal in 7 microcell hybrids (41%). However, no clear correlation was observed between the intrachromosomal rearrangements and the induction of delayed chromosomal instability by ionizing radiation

Chromosomal localization of the human vesicular amine transporter genes

Energy Technology Data Exchange (ETDEWEB)

Peter, D.; Finn, P.; Liu, Y.; Roghani, A.; Edwards, R.H.; Klisak, I.; Kojis, T.; Heinzmann, C.; Sparkes, R.S. (UCLA School of Medicine, Los Angeles, CA (United States))

1993-12-01

The physiologic and behavioral effects of pharmacologic agents that interfere with the transport of monoamine neurotransmitters into vesicles suggest that vesicular amine transport may contribute to human neuropsychiatric disease. To determine whether an alteration in the genes that encode vesicular amine transport contributes to the inherited component of these disorders, the authors have isolated a human cDNA for the brain transporter and localized the human vesciular amine transporter genes. The human brain synaptic vesicle amine transporter (SVAT) shows unexpected conservation with rat SVAT in the regions that diverge extensively between rat SVAT and the rat adrenal chromaffin granule amine transporter (CGAT). Using the cloned sequences with a panel of mouse-human hybrids and in situ hybridization for regional localization, the adrenal CGAT gene (or VAT1) maps to human chromosome 8p21.3 and the brain SVAT gene (or VAT2) maps to chromosome 10q25. Both of these sites occur very close to if not within previously described deletions that produce severe but viable phenotypes. 26 refs., 3 figs., 1 tab.

Three-dimensional genome architecture influences partner selection for chromosomal translocations in human disease.

Directory of Open Access Journals (Sweden)

Jesse M Engreitz

Full Text Available Chromosomal translocations are frequent features of cancer genomes that contribute to disease progression. These rearrangements result from formation and illegitimate repair of DNA double-strand breaks (DSBs, a process that requires spatial colocalization of chromosomal breakpoints. The "contact first" hypothesis suggests that translocation partners colocalize in the nuclei of normal cells, prior to rearrangement. It is unclear, however, the extent to which spatial interactions based on three-dimensional genome architecture contribute to chromosomal rearrangements in human disease. Here we intersect Hi-C maps of three-dimensional chromosome conformation with collections of 1,533 chromosomal translocations from cancer and germline genomes. We show that many translocation-prone pairs of regions genome-wide, including the cancer translocation partners BCR-ABL and MYC-IGH, display elevated Hi-C contact frequencies in normal human cells. Considering tissue specificity, we find that translocation breakpoints reported in human hematologic malignancies have higher Hi-C contact frequencies in lymphoid cells than those reported in sarcomas and epithelial tumors. However, translocations from multiple tissue types show significant correlation with Hi-C contact frequencies, suggesting that both tissue-specific and universal features of chromatin structure contribute to chromosomal alterations. Our results demonstrate that three-dimensional genome architecture shapes the landscape of rearrangements directly observed in human disease and establish Hi-C as a key method for dissecting these effects.

Human hereditary diseases associated with elevated frequency of chromosome aberrations

International Nuclear Information System (INIS)

Ejima, Yosuke

1988-01-01

Human recessive diseases collectively known as chromosome breakage syndromes include Fanconi's anemia, Bloom's syndrome and ataxia telangiectasia. Cells from these patients show chromosome instabilities both spontaneously and following treatments with radiations or certain chemicals, where defects in DNA metabolisms are supposed to be involved. Cells from patients with ataxia telangiectasia are hypersensitive to ionizing radiations, though DNA replication is less affected than in normal cells. Chromatid-type as well as chromosom-type aberrations are induced in cells irradiated in G 0 or G 1 phases. These unusual responses to radiations may provide clues for understanding the link between DNA replicative response and cellular radiosensitivity. Alterations in cellular radiosensitivity or spontaneous chromosome instabilities are observed in some patients with congenital chromosome anomalies or dominant diseases, where underlying defects may be different from those in recessive diseases. (author)

Human hereditary diseases associated with elevated frequency of chromosome aberrations

Energy Technology Data Exchange (ETDEWEB)

Ejima, Yosuke; Ikushima, Takaji (ed.)

1988-07-01

Human recessive diseases collectively known as chromosome breakage syndromes include Fanconi's anemia, Bloom's syndrome and ataxia telangiectasia. Cells from these patients show chromosome instabilities both spontaneously and following treatments with radiations or certain chemicals, where defects in DNA metabolisms are supposed to be involved. Cells from patients with ataxia telangiectasia are hypersensitive to ionizing radiations, though DNA replication is less affected than in normal cells. Chromatid-type as well as chromosom-type aberrations are induced in cells irradiated in G/sub 0/ or G/sub 1/ phases. These unusual responses to radiations may provide clues for understanding the link between DNA replicative response and cellular radiosensitivity. Alterations in cellular radiosensitivity or spontaneous chromosome instabilities are observed in some patients with congenital chromosome anomalies or dominant diseases, where underlying defects may be different from those in recessive diseases.

Genetic integrity of the human Y chromosome exposed to groundwater arsenic

Directory of Open Access Journals (Sweden)

Ali Sher

2010-08-01

Full Text Available Abstract Background Arsenic is a known human carcinogen reported to cause chromosomal deletions and genetic anomalies in cultured cells. The vast human population inhabiting the Ganges delta in West Bengal, India and Bangladesh is exposed to critical levels of arsenic present in the groundwater. The genetic and physiological mechanism of arsenic toxicity in the human body is yet to be fully established. In addition, lack of animal models has made work on this line even more challenging. Methods Human male blood samples were collected with their informed consent from 5 districts in West Bengal having groundwater arsenic level more than 50 μg/L. Isolation of genomic DNA and preparation of metaphase chromosomes was done using standard protocols. End point PCR was performed for established sequence tagged sites to ascertain the status of recombination events. Single nucleotide variants of candidate genes and amplicons were carried out using appropriate restriction enzymes. The copy number of DYZ1 array per haploid genome was calculated using real time PCR and its chromosomal localization was done by fluorescence in-situ hybridization (FISH. Results We studied effects of arsenic exposure on the human Y chromosome in males from different areas of West Bengal focusing on known recombination events (P5-P1 proximal; P5-P1 distal; gr/gr; TSPY-TSPY, b1/b3 and b2/b3, single nucleotide variants (SNVs of a few candidate Y-linked genes (DAZ, TTY4, BPY2, GOLGA2LY and the amplicons of AZFc region. Also, possible chromosomal reorganization of DYZ1 repeat arrays was analyzed. Barring a few microdeletions, no major changes were detected in blood DNA samples. SNV analysis showed a difference in some alleles. Similarly, DYZ1 arrays signals detected by FISH were found to be affected in some males. Conclusions Our Y chromosome analysis suggests that the same is protected from the effects of arsenic by some unknown mechanisms maintaining its structural and functional

Chromosome aberration induction in human diploid fibroblast and epithelial cells

International Nuclear Information System (INIS)

Scott, D.

1986-01-01

The relative sensitivity of cultured human fibroblasts and epithelial cells to radiation-induced chromosomal aberrations was investigated. Lung fibroblast and kidney epithelial cells from the same fetus were compared, as were skin fibroblasts and epithelial keratinocytes from the same foreskin sample. After exposure of proliferating fetal cells to 1.5 Gy X-rays there was a very similar aberration yield in the fibroblasts and epithelial cells. Observations of either little or no difference in chromosomal sensitivity between human fibroblasts and epithelial cells give added confidence that quantitative cytogenetic data obtained from cultured fibroblasts are relevant to the question of sensitivity of epithelial cells which are the predominant cell type in human cancers. (author)

Interphase Chromosome Conformation and Chromatin-Chromatin Interactions in Human Epithelial Cells Cultured Under Different Gravity Conditions

Science.gov (United States)

Zhang, Ye; Wong, Michael; Hada, Megumi; Wu, Honglu

2015-01-01

Microgravity has been shown to alter global gene expression patterns and protein levels both in cultured cells and animal models. It has been suggested that the packaging of chromatin fibers in the interphase nucleus is closely related to genome function, and the changes in transcriptional activity are tightly correlated with changes in chromatin folding. This study explores the changes of chromatin conformation and chromatin-chromatin interactions in the simulated microgravity environment, and investigates their correlation to the expression of genes located at different regions of the chromosome. To investigate the folding of chromatin in interphase under various culture conditions, human epithelial cells, fibroblasts, and lymphocytes were fixed in the G1 phase. Interphase chromosomes were hybridized with a multicolor banding in situ hybridization (mBAND) probe for chromosome 3 which distinguishes six regions of the chromosome as separate colors. After images were captured with a laser scanning confocal microscope, the 3-dimensional structure of interphase chromosome 3 was reconstructed at multi-mega base pair scale. In order to determine the effects of microgravity on chromosome conformation and orientation, measures such as distance between homologous pairs, relative orientation of chromosome arms about a shared midpoint, and orientation of arms within individual chromosomes were all considered as potentially impacted by simulated microgravity conditions. The studies revealed non-random folding of chromatin in interphase, and suggested an association of interphase chromatin folding with radiation-induced chromosome aberration hotspots. Interestingly, the distributions of genes with expression changes over chromosome 3 in cells cultured under microgravity environment are apparently clustered on specific loci and chromosomes. This data provides important insights into how mammalian cells respond to microgravity at molecular level.

Is 24-color FISH detection of in-vitro radiation-induced chromosomal aberrations suited to determine individual intrinsic radiosensitivity?

International Nuclear Information System (INIS)

Kuechler, A.; Wendt, T.G.; Neubauer, S.; Grabenbauer, G.G.; Sauer, R.; Claussen, U.; Liehr, T.

2002-01-01

Background: Reliable determination of intrinsic radiosensitivity in individual patients is a serious need in radiation oncology. Chromosomal aberrations are sensitive indicators of a previous exposure to ionizing irradiation. Former molecular cytogenetic studies showed that such aberrations as an equivalent of intrinsic radiosensitivity can be detected by fluorescence in-situ hybridization (FISH) techniques using whole chromosome painting (wcp) probes. However, only one up to three randomly chosen wcp probes have been applied for such approaches until now. As a random distribution of chromosomal rearrangements along the chromosomes is up to now still controversial, the power of the 24-color FISH approach should be elucidated in the present study. Methods and Material: Lymphocytes derived from lymphoblastoid cell lines of one patient with Nijmegen breakage syndrome (NBS homozygote) and of two NBS heterozygotes and peripheral blood lymphocytes of two controls were analyzed. Samples of each patient/control were irradiated in vitro with 0.0 Gy, 0.7 Gy or 2.0 Gy prior to cultivation. Chromosomal aberrations were analyzed in detail and quantified by means of 24-color FISH as an expression of the individual intrinsic radiosensitivity. Results: 24-color FISH analyses were done in a total of 1,674 metaphases. After in-vitro irradiation, 21% (0.7 Gy) or 57% (2.0 Gy) of the controls' cells, 15% (0.7 Gy) or 53% (2.0 Gy) of the heterozygotes' cells and 54% (0.7 Gy) or 79% (2.0 Gy) of the homozygote's cells contained aberrations. The highest average rates of breaks per mitosis [B/M] (0.7 Gy: 1.80 B/M, 2.0 Gy: 4.03 B/M) and complex chromosomal rearrangements [CCR] (0.7 Gy: 0.20 CCR/M, 2.0 Gy: 0.47 CCR/M) were observed in the NBS patient. Moreover, the proportion of different aberration types after irradiation showed a distinct increase in the rate of CCR combined with a decrease in dicentrics in the NBS homozygote. Conclusion: To come to a more complete picture of radiation

Dose-response calibration curves of {sup 137}Cs gamma rays for dicentric chromosome aberrations in human lymphocytes

Energy Technology Data Exchange (ETDEWEB)

Jo, Wol Soon; Oh, Su Jung; Jeong, Soo Kyun; Yang, Kwang Mo [Dept. of Research center, Dong Nam Institute of Radiological and Medical Sciences, Busan (Korea, Republic of); Jeong, Min Ho [Dept. of Microbiology, Dong A University College of Medicine, Busan (Korea, Republic of)

2012-11-15

Recently, the increased threat of radiologically industrial accident such as radiation nondestructive inspection or destruction of nuclear accident by natural disaster such as Fukushima accident requires a greater capacity for cytogenetic biodosimetry, which is critical for clinical triage of potentially thousands of radiation-exposed individuals. Dicentric chromosome aberration analysis is the conventional means of assessing radiation exposure. Dose–response calibration curves for {sup 13}'7Cs gamma rays have been established for unstable chromosome aberrations in human peripheral blood lymphocytes in many laboratories of international biodosimetry network. In this study, therefore, we established dose– response calibration curves of our laboratory for {sup 137}Cs gamma raysaccording to the IAEA protocols for conducting the dicentric chromosome assay We established in vitro dose–response calibration curves for dicentric chromosome aberrations in human lymphocytes for{sup 13}'7Cs gamma rays in the 0 to 5 Gy range, using the maximum likelihood linear-quadratic model, Y = c+αD+βD2. The estimated coefficients of the fitted curves were within the 95% confidence intervals (CIs) and the curve fitting of dose–effect relationship data indicated a good fit to the linear-quadratic model. Hence, meaningful dose estimation from unknown sample can be determined accurately by using our laboratory’s calibration curve according to standard protocol.

Chromosome painting analysis of X-ray-induced aberrations in human lymphocytes in vitro

International Nuclear Information System (INIS)

Matsuoka, A.; Hayashi, M.; Yamazaki, N.; Sofuni, T.

1994-01-01

Chromosomal rearrangements in human lymphocytes induced by X-rays (0, 0.5, 1.0 and 2.0 Gray) were analyzed using chromosome painting. DNA probes for human chromosomes 1, 3 or 4 alone, and a combination of 1 and 4, were used for analysis. The frequency of cells with rearrangements, i.e. reciprocal translocations, dicentrics, insertions, tricentrics and fragments, involving chromosome 4 increased with dose in both 48 and 72 h cultures. The number of translocations per cell also increased with dose at 48 and 72 h. Dicentrics increased with dose in 48 h but not in 72 h cultures. The estimated genomic frequency of aberrations per cell was comparable with results in banded cells. No difference was shown on the detection efficiency of chromosome rearrangements among the various DNA probes used. Since this technique does not necessarily require well-spread metaphases for analysis, it is possible to increase the number of analyzable metaphases compared with the banding technique. Chromosome painting is a simpler, more objective and practical method for detecting chromosome rearrangements than conventional banding analyses. (Author)

Use of chromosome translocations for measuring prior environment exposures in humans

Energy Technology Data Exchange (ETDEWEB)

Tucker, J. D.

1997-05-01

Recent advances in cytogenetic methodology are beginning to have a major impact upon our ability to provide assessments of environmental exposure in humans. The advent of fluorescent-based techniques for `painting` whole chromosomes has made the analysis of chromosome translocations rapid, specific, sensitive and routine. Chromosome painting has been used to address a wide variety of scientific questions, resulting in an increased understanding of the biological consequences of adverse environmental exposure. This paper describes the use of chromosome translocations as a biological marker of exposure and effect in humans. The relevance of translocations is discussed, as are the advantages and disadvantages of painting compared to classical cytogenetic methods for translocation evaluation. The factors to consider in the use of translocations as a retrospective indicator of exposure are then described. Several theoretical parameters that are important to the use of translocations are provided, and the paper concludes with a vision for the future of cytogenetic methodology.

Evaluating the relationship between spermatogenic silencing of the X chromosome and evolution of the Y chromosome in chimpanzee and human

NARCIS (Netherlands)

E. Mulugeta (Eskeatnaf); W.M. Baarends (Willy); J.H. Gribnau (Joost); J.A. Grootegoed (Anton)

2010-01-01

textabstractChimpanzees and humans are genetically very similar, with the striking exception of their Y chromosomes, which have diverged tremendously. The male-specific region (MSY), representing the greater part of the Y chromosome, is inherited from father to son in a clonal fashion, with natural

Fluorescent in-situ hybridization of cattle and sheep chromosomes with cloned human fragile-X DNA

DEFF Research Database (Denmark)

Ali, Ahmd; Thomsen, Preben Dybdahl; Babar, M.E.

2009-01-01

An extensive study on spontaneous and 5-Fluorodeoxyuridine induced fragile sites identified Xq31 in cattle (Bos taurus) and (Xq24, Xq26) in sheep (Ovis aries) in addition to several autosomal fragile sites (under publication). A ZOO-FISH study using three cloned human fragile-X probes with CCG....../CGG(n) trinucleotide repeat sequence was carried out to determine homology between human and bovine fragile-X. The hybridisation results showed only a weak signal on a human chromosome that was not an X with all three fragile site probes. No signals were detected in sheep chromosomes. The signal of all three human...... fragile-X probes on cattle chromosomes was however, medium-prominent sub-centromeric signal on two homologues. BrdU administration in 12 h before harvesting identified these homologues to be chromosome number 5. In addition retrospective slides of cattle and sheep chromosomes used for fragile site studies...

Chimpanzee and human Y chromosomes are remarkably divergent in structure and gene content

NARCIS (Netherlands)

Hughes, Jennifer F.; Skaletsky, Helen; Pyntikova, Tatyana; Graves, Tina A.; van Daalen, Saskia K. M.; Minx, Patrick J.; Fulton, Robert S.; McGrath, Sean D.; Locke, Devin P.; Friedman, Cynthia; Trask, Barbara J.; Mardis, Elaine R.; Warren, Wesley C.; Repping, Sjoerd; Rozen, Steve; Wilson, Richard K.; Page, David C.

2010-01-01

The human Y chromosome began to evolve from an autosome hundreds of millions of years ago, acquiring a sex-determining function and undergoing a series of inversions that suppressed crossing over with the X chromosome(1,2). Little is known about the recent evolution of the Y chromosome because only

Y Chromosome analysis of prehistoric human populations in the West Liao River Valley, Northeast China.

Science.gov (United States)

Cui, Yinqiu; Li, Hongjie; Ning, Chao; Zhang, Ye; Chen, Lu; Zhao, Xin; Hagelberg, Erika; Zhou, Hui

2013-09-30

The West Liao River valley in Northeast China is an ecologically diverse region, populated in prehistory by human populations with a wide range of cultures and modes of subsistence. To help understand the human evolutionary history of this region, we performed Y chromosome analyses on ancient human remains from archaeological sites ranging in age from 6500 to 2700 BP. 47 of the 70 individuals provided reproducible results. They were assigned into five different Y sub-haplogroups using diagnostic single nucleotide polymorphisms, namely N1 (xN1a, N1c), N1c, C/C3e, O3a (O3a3) and O3a3c. We also used 17 Y short tandem repeat loci in the non-recombining portion of the Y chromosome. There appears to be significant genetic differences between populations of the West Liao River valley and adjacent cultural complexes in the prehistoric period, and these prehistoric populations were shown to carry similar haplotypes as present-day Northeast Asians, but at markedly different frequencies. Our results suggest that the prehistoric cultural transitions were associated with immigration from the Yellow River valley and the northern steppe into the West Liao River valley. They reveal the temporal continuity of Y chromosome lineages in populations of the West Liao River valley over 5000 years, with a concurrent increase in lineage diversity caused by an influx of immigrants from other populations.

Flow cytogenetics and chromosome sorting.

Science.gov (United States)

Cram, L S

1990-06-01

This review of flow cytogenetics and chromosome sorting provides an overview of general information in the field and describes recent developments in more detail. From the early developments of chromosome analysis involving single parameter or one color analysis to the latest developments in slit scanning of single chromosomes in a flow stream, the field has progressed rapidly and most importantly has served as an important enabling technology for the human genome project. Technological innovations that advanced flow cytogenetics are described and referenced. Applications in basic cell biology, molecular biology, and clinical investigations are presented. The necessary characteristics for large number chromosome sorting are highlighted. References to recent review articles are provided as a starting point for locating individual references that provide more detail. Specific references are provided for recent developments.

Human interphase chromosomes: a review of available molecular cytogenetic technologies

Directory of Open Access Journals (Sweden)

Yurov Yuri B

2010-01-01

Full Text Available Abstract Human karyotype is usually studied by classical cytogenetic (banding techniques. To perform it, one has to obtain metaphase chromosomes of mitotic cells. This leads to the impossibility of analyzing all the cell types, to moderate cell scoring, and to the extrapolation of cytogenetic data retrieved from a couple of tens of mitotic cells to the whole organism, suggesting that all the remaining cells possess these genomes. However, this is far from being the case inasmuch as chromosome abnormalities can occur in any cell along ontogeny. Since somatic cells of eukaryotes are more likely to be in interphase, the solution of the problem concerning studying postmitotic cells and larger cell populations is interphase cytogenetics, which has become more or less applicable for specific biomedical tasks due to achievements in molecular cytogenetics (i.e. developments of fluorescence in situ hybridization -- FISH, and multicolor banding -- MCB. Numerous interphase molecular cytogenetic approaches are restricted to studying specific genomic loci (regions being, however, useful for identification of chromosome abnormalities (aneuploidy, polyploidy, deletions, inversions, duplications, translocations. Moreover, these techniques are the unique possibility to establish biological role and patterns of nuclear genome organization at suprachromosomal level in a given cell. Here, it is to note that this issue is incompletely worked out due to technical limitations. Nonetheless, a number of state-of-the-art molecular cytogenetic techniques (i.e multicolor interphase FISH or interpahase chromosome-specific MCB allow visualization of interphase chromosomes in their integrity at molecular resolutions. Thus, regardless numerous difficulties encountered during studying human interphase chromosomes, molecular cytogenetics does provide for high-resolution single-cell analysis of genome organization, structure and behavior at all stages of cell cycle.

Molecular genetic approach to human meningioma: loss of genes on chromosome 22

International Nuclear Information System (INIS)

Seizinger, B.R.; De La Monte, S.; Atkins, L.; Gusella, J.F.; Martuza, R.L.

1987-01-01

A molecular genetic approach employing polymorphic DNA markers has been used to investigate the role of chromosomal aberrations in meningioma, one of the most common tumors of the human nervous system. Comparison of the alleles detected by DNA markers in tumor DNA versus DNA from normal tissue revealed chromosomal alterations present in primary surgical specimens. In agreement with cytogenetic studies of cultured meningiomas, the most frequent alteration detected was loss of heterozygosity on chromosome 22. Forty of 51 patients were constitutionally heterozygous for at least one chromosome 22 DNA marker. Seventeen of the 40 constitutionally heterozygotic patients (43%) displayed hemizygosity for the corresponding marker in their meningioma tumor tissues. Loss of heterozygosity was also detected at a significantly lower frequency for markers on several other autosomes. In view of the striking association between acoustic neuroma and meningioma in bilateral acoustic neurofibromatosis and the discovery that acoustic neuromas display specific loss of genes on chromosome 22, the authors propose that a common mechanism involving chromosome 22 is operative in the development of both tumor types. Fine-structure mapping to reveal partial deletions in meningiomas may provide the means to clone and characterize a gene (or genes) of importance for tumorigenesis in this and possibly other clinically associated tumors of the human nervous system

Single-nucleotide variant in multiple copies of a deleted in azoospermia (DAZ) sequence - a human Y chromosome quantitative polymorphism.

Science.gov (United States)

Szmulewicz, Martin N; Ruiz, Luis M; Reategui, Erika P; Hussini, Saeed; Herrera, Rene J

2002-01-01

The evolution of the deleted in azoospermia (DAZ) gene family supports prevalent theories on the origin and development of sex chromosomes and sexual dimorphism. The ancestral DAZL gene in human chromosome 3 is known to be involved in germline development of both males and females. The available phylogenetic data suggest that some time after the divergence of the New World and Old World monkey lineages, the DAZL gene, which is found in all mammals, was copied to the Y chromosome of an ancestor to the Old World monkeys, but not New World monkeys. In modern man, the Y-linked DAZ gene complex is located on the distal part of the q arm. It is thought that after being copied to the Y chromosome, and after the divergence of the human and great ape lineages, the DAZ gene in the former underwent internal rearrangements. This included tandem duplications as well as a T > C transition altering an MboI restriction enzyme site in a duplicated sequence. In this study, we report on the ratios of MboI-/MboI+ variant sequences in individuals from seven worldwide human populations (Basque, Benin, Egypt, Formosa, Kungurtug, Oman and Rwanda) in the DAZ complex. The ratio of PCR MboI- and MboI+ amplicons can be used to characterize individuals and populations. Our results show a nonrandom distribution of MboI-/MboI+ sequence ratios in all populations examined, as well as significant differences in ratios between populations when compared pairwise. The multiple ratios imply that there have been more than one recent reorganization events at this locus. Considering the dynamic nature of this locus and its involvement in male fertility, we investigated the extent and distribution of this polymorphism. Copyright 2002 S. Karger AG, Basel

Y chromosome diversity, human expansion, drift, and cultural evolution.

Science.gov (United States)

Chiaroni, Jacques; Underhill, Peter A; Cavalli-Sforza, Luca L

2009-12-01

The relative importance of the roles of adaptation and chance in determining genetic diversity and evolution has received attention in the last 50 years, but our understanding is still incomplete. All statements about the relative effects of evolutionary factors, especially drift, need confirmation by strong demographic observations, some of which are easier to obtain in a species like ours. Earlier quantitative studies on a variety of data have shown that the amount of genetic differentiation in living human populations indicates that the role of positive (or directional) selection is modest. We observe geographic peculiarities with some Y chromosome mutants, most probably due to a drift-related phenomenon called the surfing effect. We also compare the overall genetic diversity in Y chromosome DNA data with that of other chromosomes and their expectations under drift and natural selection, as well as the rate of fall of diversity within populations known as the serial founder effect during the recent "Out of Africa" expansion of modern humans to the whole world. All these observations are difficult to explain without accepting a major relative role for drift in the course of human expansions. The increasing role of human creativity and the fast diffusion of inventions seem to have favored cultural solutions for many of the problems encountered in the expansion. We suggest that cultural evolution has been subrogating biologic evolution in providing natural selection advantages and reducing our dependence on genetic mutations, especially in the last phase of transition from food collection to food production.

Neuropeptide Y receptor genes on human chromosome 4q31-q32 map to conserved linkage groups on mouse chromosomes 3 and 8

Energy Technology Data Exchange (ETDEWEB)

Lutz, C.M.; Frankel, W.N. [Jackson Lab., Bar Harbor, ME (United States); Richards, J.E. [Univ. of Michigan Medical School, Ann Arbor, MI (United States)] [and others

1997-05-01

Npy1r and Npy2r, the genes encoding mouse type 1 and type 2 neuropeptide Y receptors, have been mapped by interspecific backcross analysis. Previous studies have localized the human genes encoding these receptors to chromosome 4q31-q32. We have now assigned Npy1r and Npy2r to conserved linkage groups on mouse Chr 8 and Chr 3, respectively, which correspond to the distal region of human chromosome 4q. Using yeast artificial chromosomes, we have estimated the distance between the human genes to be approximately 6 cM. Although ancient tandem duplication events may account for some closely spaced G-protein-coupled receptor genes, the large genetic distance between the human type 1 and type 2 neuropeptide Y receptor genes raises questions about whether this mechanism accounts for their proximity. 20 refs., 1 fig.

A role for Aurora C in the chromosomal passenger complex during human preimplantation embryo development

NARCIS (Netherlands)

Santos, Margarida Avo; van de Werken, Christine; de Vries, Marieke; Jahr, Holger; Vromans, Martijn J. M.; Laven, Joop S. E.; Fauser, Bart C.; Kops, Geert J.; Lens, Susanne M.; Baart, Esther B.

BACKGROUND: Human embryos generated by IVF demonstrate a high incidence of chromosomal segregation errors during the cleavage divisions. To analyse underlying molecular mechanisms, we investigated the behaviour of the chromosomal passenger complex (CPC) in human oocytes and embryos. This important

The Sequence and Analysis of Duplication Rich Human Chromosome 16

Science.gov (United States)

Martin, Joel; Han, Cliff; Gordon, Laurie A.; Terry, Astrid; Prabhakar, Shyam; She, Xinwei; Xie, Gary; Hellsten, Uffe; Man Chan, Yee; Altherr, Michael; Couronne, Olivier; Aerts, Andrea; Bajorek, Eva; Black, Stacey; Blumer, Heather; Branscomb, Elbert; Brown, Nancy C.; Bruno, William J.; Buckingham, Judith M.; Callen, David F.; Campbell, Connie S.; Campbell, Mary L.; Campbell, Evelyn W.; Caoile, Chenier; Challacombe, Jean F.; Chasteen, Leslie A.; Chertkov, Olga; Chi, Han C.; Christensen, Mari; Clark, Lynn M.; Cohn, Judith D.; Denys, Mirian; Detter, John C.; Dickson, Mark; Dimitrijevic-Bussod, Mira; Escobar, Julio; Fawcett, Joseph J.; Flowers, Dave; Fotopulos, Dea; Glavina, Tijana; Gomez, Maria; Gonzales, Eidelyn; Goodstein, David; Goodwin, Lynne A.; Grady, Deborah L.; Grigoriev, Igor; Groza, Matthew; Hammon, Nancy; Hawkins, Trevor; Haydu, Lauren; Hildebrand, Carl E.; Huang, Wayne; Israni, Sanjay; Jett, Jamie; Jewett, Phillip E.; Kadner, Kristen; Kimball, Heather; Kobayashi, Arthur; Krawczyk, Marie-Claude; Leyba, Tina; Longmire, Jonathan L.; Lopez, Frederick; Lou, Yunian; Lowry, Steve; Ludeman, Thom; Mark, Graham A.; Mcmurray, Kimberly L.; Meincke, Linda J.; Morgan, Jenna; Moyzis, Robert K.; Mundt, Mark O.; Munk, A. Christine; Nandkeshwar, Richard D.; Pitluck, Sam; Pollard, Martin; Predki, Paul; Parson-Quintana, Beverly; Ramirez, Lucia; Rash, Sam; Retterer, James; Ricke, Darryl O.; Robinson, Donna L.; Rodriguez, Alex; Salamov, Asaf; Saunders, Elizabeth H.; Scott, Duncan; Shough, Timothy; Stallings, Raymond L.; Stalvey, Malinda; Sutherland, Robert D.; Tapia, Roxanne; Tesmer, Judith G.; Thayer, Nina; Thompson, Linda S.; Tice, Hope; Torney, David C.; Tran-Gyamfi, Mary; Tsai, Ming; Ulanovsky, Levy E.; Ustaszewska, Anna; Vo, Nu; White, P. Scott; Williams, Albert L.; Wills, Patricia L.; Wu, Jung-Rung; Wu, Kevin; Yang, Joan; DeJong, Pieter; Bruce, David; Doggett, Norman; Deaven, Larry; Schmutz, Jeremy; Grimwood, Jane; Richardson, Paul; et al.

2004-01-01

We report here the 78,884,754 base pairs of finished human chromosome 16 sequence, representing over 99.9 percent of its euchromatin. Manual annotation revealed 880 protein coding genes confirmed by 1,637 aligned transcripts, 19 tRNA genes, 341 pseudogenes and 3 RNA pseudogenes. These genes include metallothionein, cadherin and iroquois gene families, as well as the disease genes for polycystic kidney disease and acute myelomonocytic leukemia. Several large-scale structural polymorphisms spanning hundreds of kilobasepairs were identified and result in gene content differences across humans. One of the unique features of chromosome 16 is its high level of segmental duplication, ranked among the highest of the human autosomes. While the segmental duplications are enriched in the relatively gene poor pericentromere of the p-arm, some are involved in recent gene duplication and conversion events which are likely to have had an impact on the evolution of primates and human disease susceptibility.

The sequence and analysis of duplication rich human chromosome 16

Energy Technology Data Exchange (ETDEWEB)

Martin, Joel; Han, Cliff; Gordon, Laurie A.; Terry, Astrid; Prabhakar, Shyam; She, Xinwei; Xie, Gary; Hellsten, Uffe; Man Chan, Yee; Altherr, Michael; Couronne, Olivier; Aerts, Andrea; Bajorek, Eva; Black, Stacey; Blumer, Heather; Branscomb, Elbert; Brown, Nancy C.; Bruno, William J.; Buckingham, Judith M.; Callen, David F.; Campbell, Connie S.; Campbell, Mary L.; Campbell, Evelyn W.; Caoile, Chenier; Challacombe, Jean F.; Chasteen, Leslie A.; Chertkov, Olga; Chi, Han C.; Christensen, Mari; Clark, Lynn M.; Cohn, Judith D.; Denys, Mirian; Detter, John C.; Dickson, Mark; Dimitrijevic-Bussod, Mira; Escobar, Julio; Fawcett, Joseph J.; Flowers, Dave; Fotopulos, Dea; Glavina, Tijana; Gomez, Maria; Gonzales, Eidelyn; Goodstein, David; Goodwin, Lynne A.; Grady, Deborah L.; Grigoriev, Igor; Groza, Matthew; Hammon, Nancy; Hawkins, Trevor; Haydu, Lauren; Hildebrand, Carl E.; Huang, Wayne; Israni, Sanjay; Jett, Jamie; Jewett, Phillip E.; Kadner, Kristen; Kimball, Heather; Kobayashi, Arthur; Krawczyk, Marie-Claude; Leyba, Tina; Longmire, Jonathan L.; Lopez, Frederick; Lou, Yunian; Lowry, Steve; Ludeman, Thom; Mark, Graham A.; Mcmurray, Kimberly L.; Meincke, Linda J.; Morgan, Jenna; Moyzis, Robert K.; Mundt, Mark O.; Munk, A. Christine; Nandkeshwar, Richard D.; Pitluck, Sam; Pollard, Martin; Predki, Paul; Parson-Quintana, Beverly; Ramirez, Lucia; Rash, Sam; Retterer, James; Ricke, Darryl O.; Robinson, Donna L.; Rodriguez, Alex; Salamov, Asaf; Saunders, Elizabeth H.; Scott, Duncan; Shough, Timothy; Stallings, Raymond L.; Stalvey, Malinda; Sutherland, Robert D.; Tapia, Roxanne; Tesmer, Judith G.; Thayer, Nina; Thompson, Linda S.; Tice, Hope; Torney, David C.; Tran-Gyamfi, Mary; Tsai, Ming; Ulanovsky, Levy E.; Ustaszewska, Anna; Vo, Nu; White, P. Scott; Williams, Albert L.; Wills, Patricia L.; Wu, Jung-Rung; Wu, Kevin; Yang, Joan; DeJong, Pieter; Bruce, David; Doggett, Norman; Deaven, Larry; Schmutz, Jeremy; Grimwood, Jane; Richardson, Paul; et al.

2004-08-01

We report here the 78,884,754 base pairs of finished human chromosome 16 sequence, representing over 99.9 percent of its euchromatin. Manual annotation revealed 880 protein coding genes confirmed by 1,637 aligned transcripts, 19 tRNA genes, 341 pseudogenes and 3 RNA pseudogenes. These genes include metallothionein, cadherin and iroquois gene families, as well as the disease genes for polycystic kidney disease and acute myelomonocytic leukemia. Several large-scale structural polymorphisms spanning hundreds of kilobasepairs were identified and result in gene content differences across humans. One of the unique features of chromosome 16 is its high level of segmental duplication, ranked among the highest of the human autosomes. While the segmental duplications are enriched in the relatively gene poor pericentromere of the p-arm, some are involved in recent gene duplication and conversion events which are likely to have had an impact on the evolution of primates and human disease susceptibility.

Identification of human chromosome 22 transcribed sequences with ORF expressed sequence tags

Science.gov (United States)

de Souza, Sandro J.; Camargo, Anamaria A.; Briones, Marcelo R. S.; Costa, Fernando F.; Nagai, Maria Aparecida; Verjovski-Almeida, Sergio; Zago, Marco A.; Andrade, Luis Eduardo C.; Carrer, Helaine; El-Dorry, Hamza F. A.; Espreafico, Enilza M.; Habr-Gama, Angelita; Giannella-Neto, Daniel; Goldman, Gustavo H.; Gruber, Arthur; Hackel, Christine; Kimura, Edna T.; Maciel, Rui M. B.; Marie, Suely K. N.; Martins, Elizabeth A. L.; Nóbrega, Marina P.; Paçó-Larson, Maria Luisa; Pardini, Maria Inês M. C.; Pereira, Gonçalo G.; Pesquero, João Bosco; Rodrigues, Vanderlei; Rogatto, Silvia R.; da Silva, Ismael D. C. G.; Sogayar, Mari C.; de Fátima Sonati, Maria; Tajara, Eloiza H.; Valentini, Sandro R.; Acencio, Marcio; Alberto, Fernando L.; Amaral, Maria Elisabete J.; Aneas, Ivy; Bengtson, Mário Henrique; Carraro, Dirce M.; Carvalho, Alex F.; Carvalho, Lúcia Helena; Cerutti, Janete M.; Corrêa, Maria Lucia C.; Costa, Maria Cristina R.; Curcio, Cyntia; Gushiken, Tsieko; Ho, Paulo L.; Kimura, Elza; Leite, Luciana C. C.; Maia, Gustavo; Majumder, Paromita; Marins, Mozart; Matsukuma, Adriana; Melo, Analy S. A.; Mestriner, Carlos Alberto; Miracca, Elisabete C.; Miranda, Daniela C.; Nascimento, Ana Lucia T. O.; Nóbrega, Francisco G.; Ojopi, Élida P. B.; Pandolfi, José Rodrigo C.; Pessoa, Luciana Gilbert; Rahal, Paula; Rainho, Claudia A.; da Ro's, Nancy; de Sá, Renata G.; Sales, Magaly M.; da Silva, Neusa P.; Silva, Tereza C.; da Silva, Wilson; Simão, Daniel F.; Sousa, Josane F.; Stecconi, Daniella; Tsukumo, Fernando; Valente, Valéria; Zalcberg, Heloisa; Brentani, Ricardo R.; Reis, Luis F. L.; Dias-Neto, Emmanuel; Simpson, Andrew J. G.

2000-01-01

Transcribed sequences in the human genome can be identified with confidence only by alignment with sequences derived from cDNAs synthesized from naturally occurring mRNAs. We constructed a set of 250,000 cDNAs that represent partial expressed gene sequences and that are biased toward the central coding regions of the resulting transcripts. They are termed ORF expressed sequence tags (ORESTES). The 250,000 ORESTES were assembled into 81,429 contigs. Of these, 1,181 (1.45%) were found to match sequences in chromosome 22 with at least one ORESTES contig for 162 (65.6%) of the 247 known genes, for 67 (44.6%) of the 150 related genes, and for 45 of the 148 (30.4%) EST-predicted genes on this chromosome. Using a set of stringent criteria to validate our sequences, we identified a further 219 previously unannotated transcribed sequences on chromosome 22. Of these, 171 were in fact also defined by EST or full length cDNA sequences available in GenBank but not utilized in the initial annotation of the first human chromosome sequence. Thus despite representing less than 15% of all expressed human sequences in the public databases at the time of the present analysis, ORESTES sequences defined 48 transcribed sequences on chromosome 22 not defined by other sequences. All of the transcribed sequences defined by ORESTES coincided with DNA regions predicted as encoding exons by genscan. (http://genes.mit.edu/GENSCAN.html). PMID:11070084

Molecular cytogenetics: A novel approach for measuring chromosome translocations in individuals years after exposure to low levels of ionizing radiation

International Nuclear Information System (INIS)

Lucas, J.N.; Straume, T.

1992-04-01

Chromosome painting was developed in our laboratory to facilitate rapid and accurate detection of chromosome translocations in human cells. Chromosome painting is the selective staining of one or more chromosomes by fluorescence in situ hybridization (FISH) using whole chromosome probes. This method permits essentially uniform hybridization and staining along the entire lengths of targeted chromosomes. Staining all other chromosomes a different color makes interchromosomal exchange aberrations readily apparent as bicolored chromosomes. Here we present a brief discussion of this methodology and recent results from studies in our laboratory

Chromosome-Centric Human Proteome Project Allies with Developmental Biology: A Case Study of the Role of Y Chromosome Genes in Organ Development.

Science.gov (United States)

Meyfour, Anna; Pooyan, Paria; Pahlavan, Sara; Rezaei-Tavirani, Mostafa; Gourabi, Hamid; Baharvand, Hossein; Salekdeh, Ghasem Hosseini

2017-12-01

One of the main goals of Chromosome-Centric Human Proteome Project is to identify protein evidence for missing proteins (MPs). Here, we present a case study of the role of Y chromosome genes in organ development and how to overcome the challenges facing MPs identification by employing human pluripotent stem cell differentiation into cells of different organs yielding unprecedented biological insight into adult silenced proteins. Y chromosome is a male-specific sex chromosome which escapes meiotic recombination. From an evolutionary perspective, Y chromosome has preserved 3% of ancestral genes compared to 98% preservation of the X chromosome based on Ohno's law. Male specific region of Y chromosome (MSY) contains genes that contribute to central dogma and govern the expression of various targets throughout the genome. One of the most well-known functions of MSY genes is to decide the male-specific characteristics including sex, testis formation, and spermatogenesis, which are majorly formed by ampliconic gene families. Beyond its role in sex-specific gonad development, MSY genes in coexpression with their X counterparts, as single copy and broadly expressed genes, inhibit haplolethality and play a key role in embryogenesis. The role of X-Y related gene mutations in the development of hereditary syndromes suggests an essential contribution of sex chromosome genes to development. MSY genes, solely and independent of their X counterparts and/or in association with sex hormones, have a considerable impact on organ development. In this Review, we present major recent findings on the contribution of MSY genes to gonad formation, spermatogenesis, and the brain, heart, and kidney development and discuss how Y chromosome proteome project may exploit developmental biology to find missing proteins.

Evaluation of rate of unstable chromosomal changes in human blood irradiated by X-rays: establishment of dose-response curve

International Nuclear Information System (INIS)

Mendonça, J.C.G.; Mendes, M.E.; Melo, A.M.M.A.; Silva, L.M.; Andrade, A.M.G.; Hwang, S.F.; Lima, F.F.

2017-01-01

Since the discovery of ionizing radiation, and consequently of its properties, there has been an increasing in its use, which in turn has raised concerns about the biological damage that it could cause in exposed individuals. As a result, cytogenetic dosimetry has emerged: a method that can be used as a complement or, in the absence of physical dosimetry, relating the frequency of chromosomal changes found in the blood of the exposed individual and the dose absorbed through dose-response calibration curves. This work aimed to verify the frequencies of the unstable chromosomal changes in human blood lymphocytes irradiated by X-rays of 250 kVp with different absorbed doses and later establish the dose-response calibration curves. The irradiation was performed at the CRCN-NE/CNEN-PE, Brazil metrology service on a PANTAK X-ray machine, model HF 320. The blood samples had their lymphocytes cultured in culture media and, after the processing, the metaphases were obtained. The chromosomal alterations analyzed were chromosomes dicentric, ring and isolated actinic fragments. There was an increase in frequencies of all chromosomal changes with increased absorbed dose. The calibration curves of dicentric and dicentric + rings presented good adjustments with the values of the coefficients Y = 0.0013 + 0.0271D + 0.0556D 2 (X 2 = 10.36 / GL = 6) and Y = 0.0013 + 0.0263D + 0.0640D 2 (X 2 = 7.43 / GL = 6), respectively. The establishment of these curves enables the Laboratory of Biological Dosimetry of the CRCN/NE/CNEN-PE to estimate the dose absorbed by occupationally exposed individuals and in cases of radiological accidents

Dysregulation of gene expression in the artificial human trisomy cells of chromosome 8 associated with transformed cell phenotypes.

Directory of Open Access Journals (Sweden)

Hisakatsu Nawata

Full Text Available A change in chromosome number, known as aneuploidy, is a common characteristic of cancer. Aneuploidy disrupts gene expression in human cancer cells and immortalized human epithelial cells, but not in normal human cells. However, the relationship between aneuploidy and cancer remains unclear. To study the effects of aneuploidy in normal human cells, we generated artificial cells of human primary fibroblast having three chromosome 8 (trisomy 8 cells by using microcell-mediated chromosome transfer technique. In addition to decreased proliferation, the trisomy 8 cells lost contact inhibition and reproliferated after exhibiting senescence-like characteristics that are typical of transformed cells. Furthermore, the trisomy 8 cells exhibited chromosome instability, and the overall gene expression profile based on microarray analyses was significantly different from that of diploid human primary fibroblasts. Our data suggest that aneuploidy, even a single chromosome gain, can be introduced into normal human cells and causes, in some cases, a partial cancer phenotype due to a disruption in overall gene expression.

X-Chromosomal short tandem repeat loci in the Turkish population ...

African Journals Online (AJOL)

In this study, we aimed to demonstrate the importance and utility of polymorphic short tandem repeat (STR) found on the human X chromosome and to provide the first allelic frequency data of X-STR (X chromosomal) loci in the Turkish population. Blood samples were taken from unrelated individuals (135 males and 129 ...

Chromosomal aberrations in humans induced by urban air pollution: influence of DNA repair and polymorphisms of glutathione S-transferase M1 and N-acetyltransferase 2

DEFF Research Database (Denmark)

Knudsen, Lisbeth E.; Norppa, H; Gamborg, M O

1999-01-01

We have studied the influence of individual susceptibility factors on the genotoxic effects of urban air pollution in 106 nonsmoking bus drivers and 101 postal workers in the Copenhagen metropolitan area. We used the frequency of chromosomal aberrations in peripheral blood lymphocytes as a biomar......We have studied the influence of individual susceptibility factors on the genotoxic effects of urban air pollution in 106 nonsmoking bus drivers and 101 postal workers in the Copenhagen metropolitan area. We used the frequency of chromosomal aberrations in peripheral blood lymphocytes...... that long-term exposure to urban air pollution (with traffic as the main contributor) induces chromosome damage in human somatic cells. Low DNA repair capacity and GSTM1 and NAT2 variants associated with reduced detoxification ability increase susceptibility to such damage. The effect of the GSTM1 genotype......, which was observed only in the bus drivers, appears to be associated with air pollution, whereas the NAT2 genotype effect, which affected all subjects, may influence the individual response to some other common exposure or the baseline level of chromosomal aberrations....

Y-chromosome evolution: emerging insights into processes of Y-chromosome degeneration.

Science.gov (United States)

Bachtrog, Doris

2013-02-01

The human Y chromosome is intriguing not only because it harbours the master-switch gene that determines gender but also because of its unusual evolutionary history. The Y chromosome evolved from an autosome, and its evolution has been characterized by massive gene decay. Recent whole-genome and transcriptome analyses of Y chromosomes in humans and other primates, in Drosophila species and in plants have shed light on the current gene content of the Y chromosome, its origins and its long-term fate. Furthermore, comparative analysis of young and old Y chromosomes has given further insights into the evolutionary and molecular forces triggering Y-chromosome degeneration and into the evolutionary destiny of the Y chromosome.

A high density of human communication-associated genes in chromosome 7q31-q36: differential expression in human and non-human primate cortices.

Science.gov (United States)

Schneider, E; Jensen, L R; Farcas, R; Kondova, I; Bontrop, R E; Navarro, B; Fuchs, E; Kuss, A W; Haaf, T

2012-01-01

The human brain is distinguished by its remarkable size, high energy consumption, and cognitive abilities compared to all other mammals and non-human primates. However, little is known about what has accelerated brain evolution in the human lineage. One possible explanation is that the appearance of advanced communication skills and language has been a driving force of human brain development. The phenotypic adaptations in brain structure and function which occurred on the way to modern humans may be associated with specific molecular signatures in today's human genome and/or transcriptome. Genes that have been linked to language, reading, and/or autism spectrum disorders are prime candidates when searching for genes for human-specific communication abilities. The database and genome-wide expression analyses we present here revealed a clustering of such communication-associated genes (COAG) on human chromosomes X and 7, in particular chromosome 7q31-q36. Compared to the rest of the genome, we found a high number of COAG to be differentially expressed in the cortices of humans and non-human primates (chimpanzee, baboon, and/or marmoset). The role of X-linked genes for the development of human-specific cognitive abilities is well known. We now propose that chromosome 7q31-q36 also represents a hot spot for the evolution of human-specific communication abilities. Selective pressure on the T cell receptor beta locus on chromosome 7q34, which plays a pivotal role in the immune system, could have led to rapid dissemination of positive gene variants in hitchhiking COAG. Copyright © 2012 S. Karger AG, Basel.

Early embryonic chromosome instability results in stable mosaic pattern in human tissues.

Directory of Open Access Journals (Sweden)

Hasmik Mkrtchyan

Full Text Available The discovery of copy number variations (CNV in the human genome opened new perspectives on the study of the genetic causes of inherited disorders and the aetiology of common diseases. Here, a single-cell-level investigation of CNV in different human tissues led us to uncover the phenomenon of mitotically derived genomic mosaicism, which is stable in different cell types of one individual. The CNV mosaic ratios were different between the 10 individuals studied. However, they were stable in the T lymphocytes, immortalized B lymphoblastoid cells, and skin fibroblasts analyzed in each individual. Because these cell types have a common origin in the connective tissues, we suggest that mitotic changes in CNV regions may happen early during embryonic development and occur only once, after which the stable mosaic ratio is maintained throughout the differentiated tissues. This concept is further supported by a unique study of immortalized B lymphoblastoid cell lines obtained with 20 year difference from two subjects. We provide the first evidence of somatic mosaicism for CNV, with stable variation ratios in different cell types of one individual leading to the hypothesis of early embryonic chromosome instability resulting in stable mosaic pattern in human tissues. This concept has the potential to open new perspectives in personalized genetic diagnostics and can explain genetic phenomena like diminished penetrance in autosomal dominant diseases. We propose that further genomic studies should focus on the single-cell level, to better understand the aetiology of aging and diseases mediated by somatic mutations.

Three-dimensional maps of all chromosomes in human male fibroblast nuclei and prometaphase rosettes.

Directory of Open Access Journals (Sweden)

Andreas Bolzer

2005-05-01

Full Text Available Studies of higher-order chromatin arrangements are an essential part of ongoing attempts to explore changes in epigenome structure and their functional implications during development and cell differentiation. However, the extent and cell-type-specificity of three-dimensional (3D chromosome arrangements has remained controversial. In order to overcome technical limitations of previous studies, we have developed tools that allow the quantitative 3D positional mapping of all chromosomes simultaneously. We present unequivocal evidence for a probabilistic 3D order of prometaphase chromosomes, as well as of chromosome territories (CTs in nuclei of quiescent (G0 and cycling (early S-phase human diploid fibroblasts (46, XY. Radial distance measurements showed a probabilistic, highly nonrandom correlation with chromosome size: small chromosomes-independently of their gene density-were distributed significantly closer to the center of the nucleus or prometaphase rosette, while large chromosomes were located closer to the nuclear or rosette rim. This arrangement was independently confirmed in both human fibroblast and amniotic fluid cell nuclei. Notably, these cell types exhibit flat-ellipsoidal cell nuclei, in contrast to the spherical nuclei of lymphocytes and several other human cell types, for which we and others previously demonstrated gene-density-correlated radial 3D CT arrangements. Modeling of 3D CT arrangements suggests that cell-type-specific differences in radial CT arrangements are not solely due to geometrical constraints that result from nuclear shape differences. We also found gene-density-correlated arrangements of higher-order chromatin shared by all human cell types studied so far. Chromatin domains, which are gene-poor, form a layer beneath the nuclear envelope, while gene-dense chromatin is enriched in the nuclear interior. We discuss the possible functional implications of this finding.

A First Generation Comparative Chromosome Map between Guinea Pig (Cavia porcellus) and Humans.

Science.gov (United States)

Romanenko, Svetlana A; Perelman, Polina L; Trifonov, Vladimir A; Serdyukova, Natalia A; Li, Tangliang; Fu, Beiyuan; O'Brien, Patricia C M; Ng, Bee L; Nie, Wenhui; Liehr, Thomas; Stanyon, Roscoe; Graphodatsky, Alexander S; Yang, Fengtang

2015-01-01

The domesticated guinea pig, Cavia porcellus (Hystricomorpha, Rodentia), is an important laboratory species and a model for a number of human diseases. Nevertheless, genomic tools for this species are lacking; even its karyotype is poorly characterized. The guinea pig belongs to Hystricomorpha, a widespread and important group of rodents; so far the chromosomes of guinea pigs have not been compared with that of other hystricomorph species or with any other mammals. We generated full sets of chromosome-specific painting probes for the guinea pig by flow sorting and microdissection, and for the first time, mapped the chromosomal homologies between guinea pig and human by reciprocal chromosome painting. Our data demonstrate that the guinea pig karyotype has undergone extensive rearrangements: 78 synteny-conserved human autosomal segments were delimited in the guinea pig genome. The high rate of genome evolution in the guinea pig may explain why the HSA7/16 and HSA16/19 associations presumed ancestral for eutherians and the three syntenic associations (HSA1/10, 3/19, and 9/11) considered ancestral for rodents were not found in C. porcellus. The comparative chromosome map presented here is a starting point for further development of physical and genetic maps of the guinea pig as well as an aid for genome assembly assignment to specific chromosomes. Furthermore, the comparative mapping will allow a transfer of gene map data from other species. The probes developed here provide a genomic toolkit, which will make the guinea pig a key species to unravel the evolutionary biology of the Hystricomorph rodents.

Damage of chromosoms under irradiation of human blood lymphocytes and development of bystander effect.

Science.gov (United States)

Shemetun, O V

2016-12-01

the research the distribution of radiation induced damages among chromosomes and their bands in irra diated in vitro human blood lymphocytes and in unirradiated bystander cells.Material and methods of research: cultivation of human peripheral blood lymphocytes by semi micromethod D.A. Hungerford, modeling of radiation induced bystander effect in mixed cultures consisting of irradiated in vitro and non irradiated blood lymphocytes from persons of different gender, GTG staining of metaphase chromosomes and their cytogenetic analysis. Break points in chromosomes under the formation of aberrations were identified in exposed in vitro human peripheral blood lymphocytes in doses 0.25 Gy (95 breaks in 1248 cells) and 1.0 Gy (227 breaks in 726 cells) and in non irradiated bystander cells under their joint cultivation with irradiated in vitro human lymphocytes (51 breaks in 1137 cells at irradiation of adjacent populations of lymphocytes in dose 0.25 Gy and 75 breaks in 1321 cells at irradiation of adjacent population of lymphocytes in a dose 1.0 Gy). The distribution of injuries among the chromo somes and their bands was investigated. in radiation exposed in vitro human peripheral blood lymphocytes as well as in bystander cells the fre quency of damaged bands and number of breaks which localized in them exceeded the control value (p chromosomes were damaged according to their relative length. Location of bands with increasing number of breaks coincided with the «hot spots» of chromosome damage following irradiation and fragile sites. More sensitive to damage were G negative euchromatin chromosome bands, in which were localized 82 88 % breaks. Damageability of telomeric regions in the irradiated cells had no significant difference from the control, while in bystander cells was lower than control value (p < 0.05). O. V. Shemetun.

Three-Dimensional Organization of Chromosome Territories and the Human Cell Nucleus

NARCIS (Netherlands)

T.A. Knoch (Tobias)

1999-01-01

textabstractTo study the three-dimensional organization of chromosome territories and the human interphase cell nucleus we developed models, which could be compared to experiments. Despite the successful linear sequencing of the human genome its 3D-organization is widely unknown. Using Monte

Level of heat shock proteins decreases in individuals carrying B-chromosomes in the grasshopper Eyprepocnemis plorans

DEFF Research Database (Denmark)

Teruel, M; Sørensen, Jesper Givskov; Loeschcke, Volker

2010-01-01

We analyzed the effect of B-chromosome presence on expression level of heat shock protein 70 (Hsp70) in cerebral ganglion and gonad in both males and females of the grasshopper Eyprepocnemis plorans. Two natural Spanish populations, Salobreña (Granada) and Torrox (Málaga) were assayed, the former...... harbouring a neutralized (non-driving) B-chromosome (B2) and the latter a parasitic (driving) B-chromosome (B24). The analysis was performed by Western blotting, immunostaining and densitometric measuring expression level of the Hsp70 family in adult individuals. The results showed that Hsp70 levels...

Frequencies of X-ray and fast neutron induced chromosome translocations in human peripheral blood lymphocytes as detected by in situ hybridization using chromosome specific DNA libraries

International Nuclear Information System (INIS)

Natarajan, A.T.; Darroudi, F.; Vermeulen, S.; Wiegant, J.

1992-01-01

DNA libraries of six human chromosomes were used to detect translocations in human lymphocytes induced by different doses of X-rays and fast neutrons. Results show that with X-rays, one can detect about 1.5 to 2.0 fold more translocations in comparison to dicentrics, whereas following fast neutron irradiation, the difference between these two classes of aberrations are significantly different at high doses. In addition, triple fluorescent in situ hybridization technique was used to study the frequencies of radiation-induced translocations involving a specific chromosome. Chromosome number 1 was found to be involved in translocations more frequently than chromosomes number 2, 3, 4, 8 and X. (author). 10 refs., 1 fig., 2 tabs

Protannotator: a semiautomated pipeline for chromosome-wise functional annotation of the "missing" human proteome.

Science.gov (United States)

Islam, Mohammad T; Garg, Gagan; Hancock, William S; Risk, Brian A; Baker, Mark S; Ranganathan, Shoba

2014-01-03

The chromosome-centric human proteome project (C-HPP) aims to define the complete set of proteins encoded in each human chromosome. The neXtProt database (September 2013) lists 20,128 proteins for the human proteome, of which 3831 human proteins (∼19%) are considered "missing" according to the standard metrics table (released September 27, 2013). In support of the C-HPP initiative, we have extended the annotation strategy developed for human chromosome 7 "missing" proteins into a semiautomated pipeline to functionally annotate the "missing" human proteome. This pipeline integrates a suite of bioinformatics analysis and annotation software tools to identify homologues and map putative functional signatures, gene ontology, and biochemical pathways. From sequential BLAST searches, we have primarily identified homologues from reviewed nonhuman mammalian proteins with protein evidence for 1271 (33.2%) "missing" proteins, followed by 703 (18.4%) homologues from reviewed nonhuman mammalian proteins and subsequently 564 (14.7%) homologues from reviewed human proteins. Functional annotations for 1945 (50.8%) "missing" proteins were also determined. To accelerate the identification of "missing" proteins from proteomics studies, we generated proteotypic peptides in silico. Matching these proteotypic peptides to ENCODE proteogenomic data resulted in proteomic evidence for 107 (2.8%) of the 3831 "missing proteins, while evidence from a recent membrane proteomic study supported the existence for another 15 "missing" proteins. The chromosome-wise functional annotation of all "missing" proteins is freely available to the scientific community through our web server (http://biolinfo.org/protannotator).

Repression of hTERT transcription by the introduction of chromosome 3 into human oral squamous cell carcinoma

Energy Technology Data Exchange (ETDEWEB)

Nishio, Sachiyo [Division of Oral and Maxillofacial Biopathological Surgery, Faculty of Medicine, Tottori University, 86 Nishi-cho, Yonago, Tottori, 683-8503 (Japan); Department of Biomedical Science, Institute of Regenerative Medicine and Biofunction, Graduate School of Medical Science, Tottori University, Yonago, Tottori, 683-8503 (Japan); Ohira, Takahito; Sunamura, Naohiro [Department of Biomedical Science, Institute of Regenerative Medicine and Biofunction, Graduate School of Medical Science, Tottori University, Yonago, Tottori, 683-8503 (Japan); Oshimura, Mitsuo [Chromosome Engineering Research Center, Tottori University, Yonago, Tottori, 683-8503 (Japan); Ryoke, Kazuo [Division of Oral and Maxillofacial Biopathological Surgery, Faculty of Medicine, Tottori University, 86 Nishi-cho, Yonago, Tottori, 683-8503 (Japan); Kugoh, Hiroyuki, E-mail: kugoh@med.tottori-u.ac.jp [Department of Biomedical Science, Institute of Regenerative Medicine and Biofunction, Graduate School of Medical Science, Tottori University, Yonago, Tottori, 683-8503 (Japan); Chromosome Engineering Research Center, Tottori University, Yonago, Tottori, 683-8503 (Japan)

2015-10-30

Telomerase is a ribonucleoprotein enzyme that maintains telomere length. Telomerase activity is primarily attributed to the expression of telomerase reverse transcriptase (TERT). It has been reported that introduction of an intact human chromosome 3 into the human oral squamous cell carcinoma cell line HSC3 suppresses the tumorigenicity of these cells. However, the mechanisms that regulate tumorigenicity have not been elucidated. To determine whether this reduction in tumorigenicity was accompanied by a reduction in telomerase activity, we investigated the transcriptional activation of TERT in HSC3 microcell hybrid clones with an introduced human chromosome 3 (HSC3#3). HSC#3 cells showed inhibition of hTERT transcription compared to that of the parental HSC3 cells. Furthermore, cell fusion experiments showed that hybrids of HSC3 cells and cells of the RCC23 renal carcinoma cell line, which also exhibits suppression of TERT transcription by the introduction of human chromosome 3, also displayed suppressed TERT transcription. These results suggested that human chromosome 3 may carry functionally distinct, additional TERT repressor genes. - Highlights: • hTERT mRNA expression level decreased in the chromosome 3 introduced HSC3 clones. • hTERT mRNA expression level was tend to suppressed in HSC3 and RCC23 hybrid cells. • We provide evidence that human chromosome 3 carries at least two distinct hTERT regulatory factors.

Repression of hTERT transcription by the introduction of chromosome 3 into human oral squamous cell carcinoma

International Nuclear Information System (INIS)

Nishio, Sachiyo; Ohira, Takahito; Sunamura, Naohiro; Oshimura, Mitsuo; Ryoke, Kazuo; Kugoh, Hiroyuki

2015-01-01

Telomerase is a ribonucleoprotein enzyme that maintains telomere length. Telomerase activity is primarily attributed to the expression of telomerase reverse transcriptase (TERT). It has been reported that introduction of an intact human chromosome 3 into the human oral squamous cell carcinoma cell line HSC3 suppresses the tumorigenicity of these cells. However, the mechanisms that regulate tumorigenicity have not been elucidated. To determine whether this reduction in tumorigenicity was accompanied by a reduction in telomerase activity, we investigated the transcriptional activation of TERT in HSC3 microcell hybrid clones with an introduced human chromosome 3 (HSC3#3). HSC#3 cells showed inhibition of hTERT transcription compared to that of the parental HSC3 cells. Furthermore, cell fusion experiments showed that hybrids of HSC3 cells and cells of the RCC23 renal carcinoma cell line, which also exhibits suppression of TERT transcription by the introduction of human chromosome 3, also displayed suppressed TERT transcription. These results suggested that human chromosome 3 may carry functionally distinct, additional TERT repressor genes. - Highlights: • hTERT mRNA expression level decreased in the chromosome 3 introduced HSC3 clones. • hTERT mRNA expression level was tend to suppressed in HSC3 and RCC23 hybrid cells. • We provide evidence that human chromosome 3 carries at least two distinct hTERT regulatory factors.

A revised root for the human Y chromosomal phylogenetic tree: the origin of patrilineal diversity in Africa.

Science.gov (United States)

Cruciani, Fulvio; Trombetta, Beniamino; Massaia, Andrea; Destro-Bisol, Giovanni; Sellitto, Daniele; Scozzari, Rosaria

2011-06-10

To shed light on the structure of the basal backbone of the human Y chromosome phylogeny, we sequenced about 200 kb of the male-specific region of the human Y chromosome (MSY) from each of seven Y chromosomes belonging to clades A1, A2, A3, and BT. We detected 146 biallelic variant sites through this analysis. We used these variants to construct a patrilineal tree, without taking into account any previously reported information regarding the phylogenetic relationships among the seven Y chromosomes here analyzed. There are several key changes at the basal nodes as compared with the most recent reference Y chromosome tree. A different position of the root was determined, with important implications for the origin of human Y chromosome diversity. An estimate of 142 KY was obtained for the coalescence time of the revised MSY tree, which is earlier than that obtained in previous studies and easier to reconcile with plausible scenarios of modern human origin. The number of deep branchings leading to African-specific clades has doubled, further strengthening the MSY-based evidence for a modern human origin in the African continent. An analysis of 2204 African DNA samples showed that the deepest clades of the revised MSY phylogeny are currently found in central and northwest Africa, opening new perspectives on early human presence in the continent. Copyright © 2011 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

Cytogenetic evaluation of Fansidar on human lymphocyte chromosomes in vitro.

Science.gov (United States)

Praveen, Nuzhat; Saifi, Muheet Alam; Shadab, G G H A

2011-01-01

Fansidar is a fixed combination of two antimalarial agents a diaminopyrimidine (Pyrimethamine) and a sulphonamide (Sulphadoxine) in the ratio 1:20- that have been used extensively worldwide for the treatment of Chloroquine resistant Plasmodium falciparum malaria, toxoplasmosis and Pneumocystis carinii pneumonia in patients with the acquired immunodeficiency syndrome. This study examined the effect of Fansidar on chromosomes in human lymphocyte culture. Fansidar was added to peripheral blood lymphocyte cultures in vitro at four different concentrations: 5,15, 25 and 50 microl in the ratio 1:20, 3:60, 5:100 and 10:200 microg ml(-1). Result shows that this drug induces moderate increase in the frequency of gaps, breaks and rearrangements. Therefore it can be concluded that Fansidar has moderate clastogenic effect on human chromosomes in vitro.

Techniques for imaging human metaphase chromosomes in liquid conditions by atomic force microscopy

Energy Technology Data Exchange (ETDEWEB)

Ushiki, Tatsuo; Hoshi, Osamu [Division of Microscopic Anatomy and Bio-imaging, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata 951-8510 (Japan); Shigeno, Masatsugu [SII NanoTechnology Incorporated, RBM Tsukiji Building, Shintomi 2-15-5, Chuo-ku, Tokyo 104-0041 (Japan)], E-mail: t-ushiki@med.niigata-u.ac.jp

2008-09-24

The purpose of this study was to obtain three-dimensional images of wet chromosomes by atomic force microscopy (AFM) in liquid conditions. Human metaphase chromosomes-obtained either by chromosome spreads or by an isolation technique-were observed in a dynamic mode by AFM in a buffer solution. Under suitable operating conditions with a soft triangular cantilever (with the spring constant of 0.08-0.4 N m{sup -1}), clear images of fixed chromosomes in the chromosome spread were obtained by AFM. For imaging isolated chromosomes with the height of more than 400 nm, a cantilever with a high aspect ratio probing tip was required. The combination of a Q-control system and the sampling intelligent scan (SIS) system in dynamic force mode AFM was useful for obtaining high-quality images of the isolated chromosomes, in which globular or cord-like structures about 50 nm thick were clearly observed on the surface of each chromatid.

Human Artificial Chromosomes with Alpha Satellite-Based De Novo Centromeres Show Increased Frequency of Nondisjunction and Anaphase Lag

OpenAIRE

Rudd, M. Katharine; Mays, Robert W.; Schwartz, Stuart; Willard, Huntington F.

2003-01-01

Human artificial chromosomes have been used to model requirements for human chromosome segregation and to explore the nature of sequences competent for centromere function. Normal human centromeres require specialized chromatin that consists of alpha satellite DNA complexed with epigenetically modified histones and centromere-specific proteins. While several types of alpha satellite DNA have been used to assemble de novo centromeres in artificial chromosome assays, the extent to which they fu...

Aneuploidy in immortalized human mesenchymal stem cells with non-random loss of chromosome 13 in culture.

Science.gov (United States)

Takeuchi, Masao; Takeuchi, Kikuko; Ozawa, Yutaka; Kohara, Akihiro; Mizusawa, Hiroshi

2009-01-01

Aneuploidy (an abnormal number of chromosomes) is commonly observed in most human cancer cells, highlighting the need to examine chromosomal instability in tumorigenesis. Previously, the immortalized human mesenchymal stem cell line UE6E7T-3 was shown to undergo a preferential loss of one copy of chromosome 13 after prolonged culture. Here, the loss of chromosome 13 was found to be caused by chromosome missegregation during mitosis, which involved unequal segregation, exclusion of the misaligned chromosome 13 on the metaphase plate, and trapping of chromosome 13 in the midbody region, as observed by fluorescence in situ hybridization. Near-diploid aneuploidy, not tetraploidy, was the direct result. The loss of chromosome 13 was non-random, and was detected by analysis of microsatellites and single nucleotide polymorphism-based loss of heterozygosity (LOH). Of the five microsatellite loci on chromosome 13, four loci showed microsatellite instability at an early stage in culture, and LOH was apparent at a late stage in culture. These results suggest that the microsatellite mutations cause changes in centromere integrity provoking loss of this chromosome in the UE6E7T-3 cell line. Thus, these results support the use of this cell line as a useful model for understanding the mechanism of aneuploid formation in cell cultures.

Efficient identification of Y chromosome sequences in the human and Drosophila genomes

Science.gov (United States)

Carvalho, Antonio Bernardo; Clark, Andrew G.

2013-01-01

Notwithstanding their biological importance, Y chromosomes remain poorly known in most species. A major obstacle to their study is the identification of Y chromosome sequences; due to its high content of repetitive DNA, in most genome projects, the Y chromosome sequence is fragmented into a large number of small, unmapped scaffolds. Identification of Y-linked genes among these fragments has yielded important insights about the origin and evolution of Y chromosomes, but the process is labor intensive, restricting studies to a small number of species. Apart from these fragmentary assemblies, in a few mammalian species, the euchromatic sequence of the Y is essentially complete, owing to painstaking BAC mapping and sequencing. Here we use female short-read sequencing and k-mer comparison to identify Y-linked sequences in two very different genomes, Drosophila virilis and human. Using this method, essentially all D. virilis scaffolds were unambiguously classified as Y-linked or not Y-linked. We found 800 new scaffolds (totaling 8.5 Mbp), and four new genes in the Y chromosome of D. virilis, including JYalpha, a gene involved in hybrid male sterility. Our results also strongly support the preponderance of gene gains over gene losses in the evolution of the Drosophila Y. In the intensively studied human genome, used here as a positive control, we recovered all previously known genes or gene families, plus a small amount (283 kb) of new, unfinished sequence. Hence, this method works in large and complex genomes and can be applied to any species with sex chromosomes. PMID:23921660

Efficient identification of Y chromosome sequences in the human and Drosophila genomes.

Science.gov (United States)

Carvalho, Antonio Bernardo; Clark, Andrew G

2013-11-01

Notwithstanding their biological importance, Y chromosomes remain poorly known in most species. A major obstacle to their study is the identification of Y chromosome sequences; due to its high content of repetitive DNA, in most genome projects, the Y chromosome sequence is fragmented into a large number of small, unmapped scaffolds. Identification of Y-linked genes among these fragments has yielded important insights about the origin and evolution of Y chromosomes, but the process is labor intensive, restricting studies to a small number of species. Apart from these fragmentary assemblies, in a few mammalian species, the euchromatic sequence of the Y is essentially complete, owing to painstaking BAC mapping and sequencing. Here we use female short-read sequencing and k-mer comparison to identify Y-linked sequences in two very different genomes, Drosophila virilis and human. Using this method, essentially all D. virilis scaffolds were unambiguously classified as Y-linked or not Y-linked. We found 800 new scaffolds (totaling 8.5 Mbp), and four new genes in the Y chromosome of D. virilis, including JYalpha, a gene involved in hybrid male sterility. Our results also strongly support the preponderance of gene gains over gene losses in the evolution of the Drosophila Y. In the intensively studied human genome, used here as a positive control, we recovered all previously known genes or gene families, plus a small amount (283 kb) of new, unfinished sequence. Hence, this method works in large and complex genomes and can be applied to any species with sex chromosomes.

Chromosomal abnormalities in human glioblastomas: gain in chromosome 7p correlating with loss in chromosome 10q.

Science.gov (United States)

Inda, María del Mar; Fan, Xing; Muñoz, Jorge; Perot, Christine; Fauvet, Didier; Danglot, Giselle; Palacio, Ana; Madero, Pilar; Zazpe, Idoya; Portillo, Eduardo; Tuñón, Teresa; Martínez-Peñuela, José María; Alfaro, Jorge; Eiras, José; Bernheim, Alain; Castresana, Javier S

2003-01-01

Various genomic alterations have been detected in glioblastoma. Chromosome 7p, with the epidermal growth factor receptor locus, together with chromosome 10q, with the phosphatase and tensin homologue deleted in chromosome 10 and deleted in malignant brain tumors-1 loci, and chromosome 9p, with the cyclin-dependent kinase inhibitor 2A locus, are among the most frequently damaged chromosomal regions in glioblastoma. In this study, we evaluated the genetic status of 32 glioblastomas by comparative genomic hybridization; the sensitivity of comparative genomic hybridization versus differential polymerase chain reaction to detect deletions at the phosphatase and tensin homologue deleted in chromosome 10, deleted in malignant brain tumors-1, and cyclin-dependent kinase inhibitor 2A loci and amplifications at the cyclin-dependent kinase 4 locus; the frequency of genetic lesions (gain or loss) at 16 different selected loci (including oncogenes, tumor-suppressor genes, and proliferation markers) mapping on 13 different chromosomes; and the possible existence of a statistical association between any pair of molecular markers studied, to subdivide the glioblastoma entity molecularly. Comparative genomic hybridization showed that the most frequent region of gain was chromosome 7p, whereas the most frequent losses occurred on chromosomes 10q and 13q. The only statistically significant association was found for 7p gain and 10q loss. Copyright 2002 Wiley-Liss, Inc.

Yleaf: Software for Human Y-Chromosomal Haplogroup Inference from Next-Generation Sequencing Data.

Science.gov (United States)

Ralf, Arwin; Montiel González, Diego; Zhong, Kaiyin; Kayser, Manfred

2018-05-01

Next-generation sequencing (NGS) technologies offer immense possibilities given the large genomic data they simultaneously deliver. The human Y-chromosome serves as good example how NGS benefits various applications in evolution, anthropology, genealogy, and forensics. Prior to NGS, the Y-chromosome phylogenetic tree consisted of a few hundred branches, based on NGS data, it now contains many thousands. The complexity of both, Y tree and NGS data provide challenges for haplogroup assignment. For effective analysis and interpretation of Y-chromosome NGS data, we present Yleaf, a publically available, automated, user-friendly software for high-resolution Y-chromosome haplogroup inference independently of library and sequencing methods.

Unique signatures of natural background radiation on human Y chromosomes from Kerala, India.

Directory of Open Access Journals (Sweden)

Sanjay Premi

Full Text Available The most frequently observed major consequences of ionizing radiation are chromosomal lesions and cancers, although the entire genome may be affected. Owing to its haploid status and absence of recombination, the human Y chromosome is an ideal candidate to be assessed for possible genetic alterations induced by ionizing radiation. We studied the human Y chromosome in 390 males from the South Indian state of Kerala, where the level of natural background radiation (NBR is ten-fold higher than the worldwide average, and that from 790 unexposed males as control.We observed random microdeletions in the Azoospermia factor (AZF a, b and c regions in >90%, and tandem duplication and copy number polymorphism (CNP of 11 different Y-linked genes in about 80% of males exposed to NBR. The autosomal homologues of Y-linked CDY genes largely remained unaffected. Multiple polymorphic copies of the Y-linked genes showing single Y-specific signals suggested their tandem duplication. Some exposed males showed unilocus duplication of DAZ genes resulting in six copies. Notably, in the AZFa region, approximately 25% of exposed males showed deletion of the DBY gene, whereas flanking genes USP9Y and UTY remained unaffected. All these alterations were detected in blood samples but not in the germline (sperm samples.Exposure to high levels of NBR correlated with several interstitial polymorphisms of the human Y chromosome. CNPs and enhanced transcription of the SRY gene after duplication are envisaged to compensate for the loss of Y chromosome in some cells. The aforesaid changes, confined to peripheral blood lymphocytes, suggest a possible innate mechanism protecting the germline DNA from the NBR. Genome analysis of a larger population focusing on greater numbers of genes may provide new insights into the mechanisms and risks of the resultant genetic damages. The present work demonstrates unique signatures of NBR on human Y chromosomes from Kerala, India.

Loss of heterozygosity on the X chromosome in human breast cancer.

Science.gov (United States)

Loupart, M L; Adams, S; Armour, J A; Walker, R; Brammar, W; Varley, J

1995-08-01

The analysis of loss of heterozygosity (LOH) in tumours can be a powerful tool for mapping the sites of tumour suppressor genes in the human genome. A panel of breast cancer patients was assembled as pairs of tumour and lymphocyte DNA samples and LOH studies carried out by Southern hybridisation with polymorphic loci mapping to the X chromosome with appropriate controls. Deletion mapping revealed a high frequency of small regionalised deletions, defining at least three independent regions, one of which is particularly well mapped to a 500 kb stretch of DNA in the distal portion of the pseudoautosomal region of Xp. A second region has been identified within the pseudoautosomal region close to the pseudoautosomal boundary, and there is a third discrete site of loss on distal Xq. Perturbations of sequences at these regions represent independent events in a number of patients. This study represents the first detailed analysis of LOH on the X chromosome in human breast tumours, the results of which indicate that at least three regions of this chromosome are involved in the disease.

Developing de novo human artificial chromosomes in embryonic stem cells using HSV-1 amplicon technology.

Science.gov (United States)

Moralli, Daniela; Monaco, Zoia L

2015-02-01

De novo artificial chromosomes expressing genes have been generated in human embryonic stem cells (hESc) and are maintained following differentiation into other cell types. Human artificial chromosomes (HAC) are small, functional, extrachromosomal elements, which behave as normal chromosomes in human cells. De novo HAC are generated following delivery of alpha satellite DNA into target cells. HAC are characterized by high levels of mitotic stability and are used as models to study centromere formation and chromosome organisation. They are successful and effective as gene expression vectors since they remain autonomous and can accommodate larger genes and regulatory regions for long-term expression studies in cells unlike other viral gene delivery vectors currently used. Transferring the essential DNA sequences for HAC formation intact across the cell membrane has been challenging for a number of years. A highly efficient delivery system based on HSV-1 amplicons has been used to target DNA directly to the ES cell nucleus and HAC stably generated in human embryonic stem cells (hESc) at high frequency. HAC were detected using an improved protocol for hESc chromosome harvesting, which consistently produced high-quality metaphase spreads that could routinely detect HAC in hESc. In tumour cells, the input DNA often integrated in the host chromosomes, but in the host ES genome, it remained intact. The hESc containing the HAC formed embryoid bodies, generated teratoma in mice, and differentiated into neuronal cells where the HAC were maintained. The HAC structure and chromatin composition was similar to the endogenous hESc chromosomes. This review will discuss the technological advances in HAC vector delivery using HSV-1 amplicons and the improvements in the identification of de novo HAC in hESc.

Mutational landscape of the human Y chromosome-linked genes ...

Indian Academy of Sciences (India)

Mutational landscape of the human Y chromosome-linked genes and loci in patients with hypogonadism. Deepali Pathak, Sandeep Kumar Yadav, Leena Rawal and Sher Ali. J. Genet. 94, 677–687. Table 1. Details showing age, sex, karyotype, clinical features and diagnosis results of the patients with H. Hormone profile.

Establishment of a molecular genetic map of distal mouse chromosome 1: further definition of a conserved linkage group syntenic with human chromosome 1q.

Science.gov (United States)

Seldin, M F; Morse, H C; LeBoeuf, R C; Steinberg, A D

1988-01-01

A linkage map of distal mouse chromosome 1 was constructed by restriction fragment length polymorphism analysis of DNAs from seven sets of recombinant inbred (RI) strains. The data obtained with seven probes on Southern hybridization combined with data from previous studies suggest the gene order Cfh, Pep-3/Ren-1,2, Ly-5, Lamb-2, At-3, Apoa-2/Ly-17,Spna-1. These results confirm and extend analyses of a large linkage group which includes genes present on a 20-30 cM span of mouse chromosome 1 and those localized to human chromosome 1q21-32. Moreover, the data indicate similar relative positions of human and mouse complement receptor-related genes REN, CD45, LAMB2, AT3, APOA2, and SPTA. These results suggest that mouse gene analyses may help in detailed mapping of human genes within such a syntenic group.

Evaluation of chromosome aberration frequency instable in individual groups residents at the municipality of Monte Alegre, Para, Brazil, exposed to radon

International Nuclear Information System (INIS)

Yunes, Samira Nogarol

2010-01-01

The municipality of Monte Alegre is a region that presents natural radiation high due to the presence of the radionuclide uranium ( 238 U) in its soil, which through its decay gives rise to element Rn, a gas. The radioactivity of the rocks has become a problem for the population of Monte Alegre, from the moment when the radioactive material began to be used in the construction of houses and paving of streets. Among all bio markers related to environmental exposures and its biological effects, the chromosomal aberrations are considered good bio markers as predictors of the risk of cancer. Studies suggest that the frequency of chromosomal aberrations may be related to the genetic instability individual and/or exposure to ionizing radiation. Our work aimed to evaluate the frequency of chromosomal aberrations in individuals in the region of high natural radioactivity in Monte Alegre-PA. As well as to correlate the cytogenetic analysis made in this study with the results of analysis of frequency of polymorphisms of genes of DNA repair carried out in another study that resulted in other dissertation. In accordance with the distribution of the data obtained in characterizing environmental radiological and in the calculation of dose, were chosen residents of homes with more and less exposure to radiation. The samples of peripheral blood of 85 individuals of the resident population of the region of Monte Alegre - PA were collected and examine provided two slides for individual was performed to verify the quality of the sample. Through this evaluation we decide that 33% of the material collected, or is, samples of 28 individuals were in suitable conditions for analysis of the frequency of chromosomal aberrations. After the collections lymphocytes present in the sample were cultivated in accordance with the methodology proposed for obtaining of cells in metaphase. were analyzed 6,177 metaphases of 28 individuals among which were found dicentric chromosomes 4 and 19 fragments

Genetic and chromosomal effects of ionizing radiation

International Nuclear Information System (INIS)

Anon.

1981-01-01

The genetic and chromosomal effects of ionizing radiations deal with those effects in the descendants of the individuals irradiated. The information base concerning genetic and chromosomal injury to humans from radiation is less adequate than is the information base for cancer and leukemia. As a result, it is not possible to make the kinds of quantitative estimates that have been made for carcinogenesis in previous chapters of this book. The chapter includes a detailed explanation of various types of genetic injuries such as chromosomal diseases, x-linked diseases, autosomal dominant diseases, recessive diseases, and irregularly inherited diseases. Quantitative estimates of mutation rates and incidences are given based on atomic bomb survivors data

Transfection of normal human and Chinese hamster DNA corrects diepoxybutane-induced chromosomal hypersensitivity of Fanconi anemia fibroblasts

International Nuclear Information System (INIS)

Shaham, M.; Adler, B.; Ganguly, S.; Chaganti, R.S.K.

1987-01-01

Cultured cells from individuals affected with Fanconi anemia (FA) exhibit spontaneous chromosome breakage and hypersensitivity to the cell killing and clastogenic effects of the difunctional alkylating agent diepoxybutane (DEB). The authors report here the correction of both of these DEB-hypersensitivity phenotypes of FA cells achieved by cotransfection of normal placental of Chinese hamster lung cell DNA and the plasmid pSV2-neo-SVgpt. Transfectants were selected for clonogenic survival after treatment with DEB at a dose of 5 μgml. At this dose of DEB, the clonogenicity of normal fibroblasts was reduced to 50% and that of FA fibroblasts was reduced to zero. DEB-resistant (DEB/sup r/) colonies selected in this system exhibited a normal response to DEB-induced chromosome breakage and resistance to repeated DEB treatment. The neo and gpt sequences were detected by Southern blot analysis of DNA from one of four DEB/sup r/ colonies independently derived from transfection of human DNA and one of three DEB/sup r/ colonies independently derived from transfection of Chinese hamster DNA. The results demonstrate that DNA sequences that complement the two hallmark cellular phenotypes (cellular and chromosomal hypersensitivity to alkylating agents) of FA are present in human as well as Chinese hamster DNA. The cloning of these genes using transfection strategies can be expected to enable molecular characterization of FA

An integrated physical map of 210 markers assigned to the short arm of human chromosome 11

NARCIS (Netherlands)

Redeker, E.; Hoovers, J. M.; Alders, M.; van Moorsel, C. J.; Ivens, A. C.; Gregory, S.; Kalikin, L.; Bliek, J.; de Galan, L.; van den Bogaard, R.; Visser, J.; van der Voort, R.; Feinberg, A. P.; Little, P. F. R.; Westerveld, A.; Mannens, M.

1994-01-01

Using a panel of patient cell lines with chromosomal breakpoints, we constructed a physical map for the short arm of human chromosome 11. We focused on 11p15, a chromosome band harboring at least 25 known genes and associated with the Beckwith-Wiedemann syndrome, several childhood tumors, and

Three-Dimensional Organization of Chromosome Territories and the Human Interphase Cell Nucleus

NARCIS (Netherlands)

T.A. Knoch (Tobias); C. Münkel (Christian); J. Langowski (Jörg)

1998-01-01

textabstractTo study the three-dimensional organization of chromosome territories and the human interphase cell nucleus we developed models which could be compared to experiments. Despite the successful linear sequencing of the human genome its 3D-organization is widely unknown. Using Monte

Mapping of the human APOB gene to chromosome 2p and demonstration of a two-allele restriction fragment length polymorphism

International Nuclear Information System (INIS)

Huang, L.; Miller, D.A.; Bruns, G.A.P.; Breslow, J.L.

1986-01-01

ApoB is a large glycoprotein with an apparent molecular mass of 550 kDa on NaDodSO 4 /PAGE. Recently, apoB cDNA clones have been isolated from an expression library made with mRNA from a human hepatoma cell line. These clones, which were all 1.5-1.6 kilobases (kb) long and corresponded to the 3' end of apoB mRNA, were used to demonstrate that hepatic apoB mRNA is ≅ 22 kb long. In the current report, a probe derived from one of these cDNA clones, pB8, was used for in situ hybridization experiments to map the human gene for apoB, APOB, to the distal half of the short arm of chromosome 2. This probe was also used to analyze somatic cell hybrids and, in agreement with the in situ hybridization studies, concordancy was demonstrated with chromosome 2. In addition, two hybrids with chromosome 2 translocations that contain only the short arm reacted with the pB8 probe. A third hybrid with a complex rearrangement of chromosome 2, which deleted an interstitial region and the tip of the short arm of chromosome 2, did not react. These data indicate that APOB maps to either 2p21-p23 or 2p24-pter. In further studies, DNA from normal individuals, digested with the restriction endonuclease EcoRI and subjected to Southern blot analysis with the pB8 probe, revealed a two-allele restriction fragment length polymorphism (RFLP). The mapping studies provide the means for understanding the relationship of the APOB locus to others in the human genome, whereas the demonstration of an APOB RFLP increases their ability to assess the role of this locus in determining plasma lipoprotein levels

Molecular analysis of the distribution of chromosomal breakpoints: characterization of a 'hot' region for breaks in human chromosome 11

International Nuclear Information System (INIS)

Vannais, D.B.; Hirai, Y.; Cologne, J.B.; Waldren, C.A.; Ueno, A.

2003-01-01

Full text: Ionizing radiation randomly damages DNA and chromosomes whereas subsequent chromosome breaks are non-random. Assuming, as an ideal and naive but useful proposition, that breaks are equally likely anywhere in the chromosome and that a deletion always occurs between two breaks, the frequency of fragments would decrease linearly with increasing fragment size. This simple distribution is not, however, observed. To shed light on the 'real' situation of break formation we mapped breakpoints in the human chromosome no. 11 of 353 independent CD59- mutants isolated from human/hamster hybrid AL cells exposed to radiations (high and low dose-rate gamma rays, high LET carbon or nitrogen ions, protons) or chemicals (arsenic or irradiated, mutagenic histidine) or unexposed. The number of breaks per unit length of DNA differed significantly in different regions of chromosome 11.The highest level of breaks (140/mbp) were in the 0.8 mbp segment between CD59 and Catalase (CAT). Finer mapping of break points was carried out using 26 PCR primer pairs spread across this interval in 15 independent mutants. In two mutants, the break point was in a 107 bp fragment; in the other 13 the breaks were in a single 35 mbp fragment, but not all were at exactly the same site; 4 of 13 occurred in 3 different 3 mbp sub-segments. We are sequencing these fragments to look for such features as repeats: 'colder' regions like that between CD59 and WT will also be analyzed. But, since at least some breaks occurred at different sites and the frequency and distribution of breaks was about the same for all treatments, our we postulate that hot (and cold spots) may be due more to structural features or specific repair than to sequence or type of damage

Chromosomal locations of members of a family of novel endogenous human retroviral genomes

International Nuclear Information System (INIS)

Horn, T.M.; Huebner, K.; Croce, C.; Callahan, R.

1986-01-01

Human cellular DNA contains two distinguishable families of retroviral related sequences. One family shares extensive nucleotide sequence homology with infectious mammalian type C retroviral genomes. The other family contains major regions of homology with the pol genes of infectious type A and B and avian type C and D retroviral genomes. Analysis of the human recombinant clone HLM-2 has shown that the pol gene in the latter family is located within an endogenous proviral genome. The authors show that the proviral genome in HLM-2 and the related recombinant clone HLM-25 are located, respectively, on human chromosomes 1 and 5. Other related proviral genomes are located on chromosomes 7, 8, 11, 14, and 17

Effect of borax on immune cell proliferation and sister chromatid exchange in human chromosomes.

Science.gov (United States)

Pongsavee, Malinee

2009-10-30

Borax is used as a food additive. It becomes toxic when accumulated in the body. It causes vomiting, fatigue and renal failure. The heparinized blood samples from 40 healthy men were studied for the impact of borax toxicity on immune cell proliferation (lymphocyte proliferation) and sister chromatid exchange in human chromosomes. The MTT assay and Sister Chromatid Exchange (SCE) technic were used in this experiment with the borax concentrations of 0.1, 0.15, 0.2, 0.3 and 0.6 mg/ml. It showed that the immune cell proliferation (lymphocyte proliferation) was decreased when the concentrations of borax increased. The borax concentration of 0.6 mg/ml had the most effectiveness to the lymphocyte proliferation and had the highest cytotoxicity index (CI). The borax concentrations of 0.15, 0.2, 0.3 and 0.6 mg/ml significantly induced sister chromatid exchange in human chromosomes (P Borax had effects on immune cell proliferation (lymphocyte proliferation) and induced sister chromatid exchange in human chromosomes. Toxicity of borax may lead to cellular toxicity and genetic defect in human.

Chromosomal changes in cultured human epithelial cells transformed by low- and high-LET radiation

Energy Technology Data Exchange (ETDEWEB)

Yang, Tracy Chui-hsu; Craise, L.M; Prioleau, J.C.; Stampfer, M.R.; Rhim, J.S.

1990-11-01

For a better assessment of radiation risk in space, an understanding of the responses of human cells, especially the epithelial cells, to low- and high-LET radiation is essential. In our laboratory, we have successfully developed techniques to study the neoplastic transformation of two human epithelial cell systems by ionizing radiation. These cell systems are human mammary epithelial cells (H184B5) and human epidermal keratinocytes (HEK). Both cell lines are immortal, anchorage dependent for growth, and nontumorigenic in athymic nude nice. Neoplastic transformation was achieved by irradiation cells successively. Our results showed that radiogenic cell transformation is a multistep process and that a single exposure of ionizing radiation can cause only one step of transformation. It requires, therefore, multihits to make human epithelial cells fully tumorigenic. Using a simple karyotyping method, we did chromosome analysis with cells cloned at various stages of transformation. We found no consistent large terminal deletion of chromosomes in radiation-induced transformants. Some changes of total number of chromosomes, however, were observed in the transformed cells. These transformants provide an unique opportunity for further genetic studies at a molecular level. 15 refs., 9 figs., 2 tabs.

Chromosomal changes in cultured human epithelial cells transformed by low- and high-LET radiation

International Nuclear Information System (INIS)

Yang, Tracy Chui-hsu; Craise, L.M; Prioleau, J.C.; Stampfer, M.R.; Rhim, J.S.

1990-11-01

For a better assessment of radiation risk in space, an understanding of the responses of human cells, especially the epithelial cells, to low- and high-LET radiation is essential. In our laboratory, we have successfully developed techniques to study the neoplastic transformation of two human epithelial cell systems by ionizing radiation. These cell systems are human mammary epithelial cells (H184B5) and human epidermal keratinocytes (HEK). Both cell lines are immortal, anchorage dependent for growth, and nontumorigenic in athymic nude nice. Neoplastic transformation was achieved by irradiation cells successively. Our results showed that radiogenic cell transformation is a multistep process and that a single exposure of ionizing radiation can cause only one step of transformation. It requires, therefore, multihits to make human epithelial cells fully tumorigenic. Using a simple karyotyping method, we did chromosome analysis with cells cloned at various stages of transformation. We found no consistent large terminal deletion of chromosomes in radiation-induced transformants. Some changes of total number of chromosomes, however, were observed in the transformed cells. These transformants provide an unique opportunity for further genetic studies at a molecular level. 15 refs., 9 figs., 2 tabs

Effects of alpha-particles on survival and chromosomal aberrations in human mammary epithelial cells

Science.gov (United States)

Durante, M.; Grossi, G. F.; Gialanella, G.; Pugliese, M.; Nappo, M.; Yang, T. C.

1995-01-01

We have studied the radiation responses of a human mammary epithelial cell line, H184B5 F5-1 M/10. This cell line was derived from primary mammary cells after treatment with chemicals and heavy ions. The F5-1 M/10 cells are immortal, density-inhibited in growth, and non-tumorigenic in athymic nude mice and represent an in vitro model of the human epithelium for radiation studies. Because epithelial cells are the target of alpha-particles emitted from radon daughters, we concentrated our studies on the efficiency of alpha-particles. Confluent cultures of M/10 cells were exposed to accelerated alpha-particles [beam energy incident at the cell monolayer = 3.85 MeV, incident linear energy transfer (LET) in cell = 109 keV/microns] and, for comparison, to 80 kVp x-rays. The following endpoints were studied: (1) survival, (2) chromosome aberrations at the first postirradiation mitosis, and (3) chromosome alterations at later passages following irradiation. The survival curve was exponential for alpha-particles (D0 = 0.73 +/- 0.04 Gy), while a shoulder was observed for x-rays (alpha/beta = 2.9 Gy; D0 = 2.5 Gy, extrapolation number 1.6). The relative biological effectiveness (RBE) of high-LET alpha-particles for human epithelial cell killing was 3.3 at 37% survival. Dose-response curves for the induction of chromosome aberrations were linear for alpha-particles and linearquadratic for x-rays. The RBE for the induction of chromosome aberrations varied with the type of aberration scored and was high (about 5) for chromosome breaks and low (about 2) for chromosome exchanges.(ABSTRACT TRUNCATED AT 250 WORDS).

Effect of estradiol on radiation-induced chromosome aberrations in human lymphocytes

International Nuclear Information System (INIS)

Kanda, Reiko; Hayata, Isamu

1999-01-01

As a part of studies on physiological factors that affect radiosensitivity, we examined the in vitro effect of estradiol (E2) on the yield of radiation-induced chromosome aberrations in human peripheral lymphocytes. Lymphocytes were cultured for 3 days in the medium containing E2 at 0-100000 ng/ml. On the second day, they were irradiated by X-rays at 3 Gy, and then 2% phytohemagglutinin and 0.05 μg/ml colcemid were added to the medium. After further 48 h, mitotic indices and the yields of chromosome aberrations were examined at various E2 concentrations. E2 treatment at concentrations above 1000 ng/ml resulted in dose-related inhibition of mitosis. Repeated experiments showed that the yield of dicentrics plus centric rings in the culture containing E2 at 100 ng/ml was significantly higher than the yields at 0 ng/ml. Similarly, the yield of total chromosome breaks in the culture containing E2 at 100 ng/ml was significantly higher than that at 1 ng/ml. This study provides the direct evidence in human that radiosensitivity may vary in relation to hormonal conditions. (author)

Active role of a human genomic insert in replication of a yeast artificial chromosome.

Science.gov (United States)

van Brabant, A J; Fangman, W L; Brewer, B J

1999-06-01

Yeast artificial chromosomes (YACs) are a common tool for cloning eukaryotic DNA. The manner by which large pieces of foreign DNA are assimilated by yeast cells into a functional chromosome is poorly understood, as is the reason why some of them are stably maintained and some are not. We examined the replication of a stable YAC containing a 240-kb insert of DNA from the human T-cell receptor beta locus. The human insert contains multiple sites that serve as origins of replication. The activity of these origins appears to require the yeast ARS consensus sequence and, as with yeast origins, additional flanking sequences. In addition, the origins in the human insert exhibit a spacing, a range of activation efficiencies, and a variation in times of activation during S phase similar to those found for normal yeast chromosomes. We propose that an appropriate combination of replication origin density, activation times, and initiation efficiencies is necessary for the successful maintenance of YAC inserts.

Energy homeostasis targets chromosomal reconfiguration of the human GH1 locus.

Science.gov (United States)

Vakili, Hana; Jin, Yan; Cattini, Peter A

2014-11-01

Levels of pituitary growth hormone (GH), a metabolic homeostatic factor with strong lipolytic activity, are decreased in obese individuals. GH declines prior to the onset of weight gain in response to excess caloric intake and hyperinsulinemia; however, the mechanism by which GH is reduced is not clear. We used transgenic mice expressing the human GH (hGH) gene, GH1, to assess the effect of high caloric intake on expression as well as the local chromosome structure of the intact GH1 locus. Animals exposed to 3 days of high caloric intake exhibited hyperinsulinemia without hyperglycemia and a decrease in both hGH synthesis and secretion, but no difference in endogenous production of murine GH. Efficient GH1 expression requires a long-range intrachromosomal interaction between remote enhancer sequences and the proximal promoter region through "looping" of intervening chromatin. High caloric intake disrupted this interaction and decreased both histone H3/H4 hyperacetylation and RNA polymerase II occupancy at the GH1 promoter. Incorporation of physical activity muted the effects of excess caloric intake on insulin levels, GH1 promoter hyperacetylation, chromosomal architecture, and expression. These results indicate that energy homeostasis alters postnatal hGH synthesis through dynamic changes in the 3-dimensional chromatin structure of the GH1 locus, including structures required for cell type specificity during development.

Report on the Second International Workshop on Human Chromosome 9

Energy Technology Data Exchange (ETDEWEB)

Kwiatkowski, D.J. [Brigham and Women`s Hospital, Boston, MA (United States); Armour, J. [Univ. of Leicester (England). Dept. of Genetics; Bale, A.E. [Yale Univ., New Haven, CT (United States). Dept. of Genetics] [and others

1993-12-31

The Second International Workshop on Human Chromosome 9 was held in Chatham, Massachusetts on April 18--20, 1993. Fifty-three abstracts were received and the data presented on posters. The purpose of the meeting was to bring together all interested investigators working on the map of chromosome 9, many of whom had disease-specific interests. After a brief presentation of interests and highlighted results, the meeting broke up into the following subgroups for production of consensus maps: 9p; 9cen-q32; 9q32 ter. A global mapping group also met. Reports of each of these working groups is presented in the summary.

Radiobiological application of atomic force microscopy. Analysis on human chromosomes in culture medium

International Nuclear Information System (INIS)

Watanabe, Makoto; Kinjo, Yasuhito

1995-01-01

We have proposed a 'Heterogeneous Chromatin Target Model' on the regulating mechanisms involved in chromosome mutation due to ionizing radiations. The heterogeneity of chromatin is derived from the highly condensed organization of chromatin segments that consist of hypersensitive and fragile sites in the fluctuating assembly of nucleosome clusters (superbeads). The above consideration is going to be subjected to a new experimental approach applying the atomic force microscope (AFM), one of the most promising members of a family of scanning probe microscope (SPM). The AFM can be operated in liquid as well as in air. A living specimen can be examined without any preparative procedures (for instance, fixation, staining, vecuum evaporation and so on). Micromanipulation of the isolated chromosome is also possible by the precise positional control of a cantilever on the nanometer scale. In the present report, the mitotic metaphase chromosomes released from living cells (human lymphocytes RPMI) were spread on the clean surface of distilled water filled in a trough. The spread surface film, in which the chromosomes were embedded, was picked up and adhered tightly on a specimen substrate made of silicon. The whole-mounted chromosome were submerged in a solution of culture medium and observed within a liquid immersion cell for AFM. We used an AFM system, SPA-300 made by Seiko Instruments. The particulate chromatin segments of nucleosome clusters (superbeads) were clearly observed within mitotic human chromosomes in a living hydrated condition. These findings support the heterogeneity of chromatin target in a living cell. (author)

Different radiosensitization effects of the halogenated compounds on the human chromosome in vitro

International Nuclear Information System (INIS)

Kang, Y.S.

1976-01-01

Unscheduled DNA synthesis and chromosome aberrations were compared following X- or UV-irradiation or methyl methanesulfonate treatment in cultures of HeLa S 3 or KB cells or human and rabbit lymphocytes. The sensitization by incorporation of the halouridines BUdR and IUdR was also investigated. Unscheduled DNA synthesis occurred in two established cell lines after irradiation with 0 to 10 kR of X-rays. The rate of unscheduled synthesis was dose dependent and differed for the two cell lines. The unscheduled synthesis was not correlated with the modal chromosome number nor with the number of aberrations produced. UV-irradiated rabbit lymphocytes exhibited unscheduled DNA synthesis which saturated after a dose of 250 ergs/mm 2 . In contrast the incorporation of BUdR or IUdR eliminated this saturation and caused an increasing effect with increasing dose up to 1000 ergs/mm 2 . The degree of sensitization varied between the two halo-uridines, BUdR being more effective at high doses while IUdR was a more potent sensitizer at low doses. Chromosome aberrations were not directly related to unscheduled DNA synthesis but were sensitized by halo-uridine incorporation. In this case IUdR was more potent than BUdR at all doses studied. Methyl methanesulfonate was an effective producer of chromosome aberration in human lymphocytes of both the chromosome and chromatid type. Prior incorporation of BUdR or IUdR did not increase the total aberration produced but did increase the number of chromosome type aberration at the expense of the chromatid type

An Allometric Analysis of Sex and Sex Chromosome Dosage Effects on Subcortical Anatomy in Humans

Science.gov (United States)

Clasen, Liv; Giedd, Jay N.; Blumenthal, Jonathan; Lerch, Jason P.; Chakravarty, M. Mallar; Raznahan, Armin

2016-01-01

Structural neuroimaging of humans with typical and atypical sex-chromosome complements has established the marked influence of both Yand X-/Y-chromosome dosage on total brain volume (TBV) and identified potential cortical substrates for the psychiatric phenotypes associated with sex-chromosome aneuploidy (SCA). Here, in a cohort of 354 humans with varying karyotypes (XX, XY, XXX, XXY, XYY, XXYY, XXXXY), we investigate sex and SCA effects on subcortical size and shape; focusing on the striatum, pallidum and thalamus. We find large effect-size differences in the volume and shape of all three structures as a function of sex and SCA. We correct for TBV effects with a novel allometric method harnessing normative scaling rules for subcortical size and shape in humans, which we derive here for the first time. We show that all three subcortical volumes scale sublinearly with TBV among healthy humans, mirroring known relationships between subcortical volume and TBV among species. Traditional TBV correction methods assume linear scaling and can therefore invert or exaggerate sex and SCA effects on subcortical anatomy. Allometric analysis restricts sex-differences to: (1) greater pallidal volume (PV) in males, and (2) relative caudate head expansion and ventral striatum contraction in females. Allometric analysis of SCA reveals that supernumerary X- and Y-chromosomes both cause disproportionate reductions in PV, and coordinated deformations of striatopallidal shape. Our study provides a novel understanding of sex and sex-chromosome dosage effects on subcortical organization, using an allometric approach that can be generalized to other basic and clinical structural neuroimaging settings. SIGNIFICANCE STATEMENT Sex and sex-chromosome dosage (SCD) are known to modulate human brain size and cortical anatomy, but very little is known regarding their impact on subcortical structures that work with the cortex to subserve a range of behaviors in health and disease. Moreover

Early embryonic failure: Expression and imprinted status of candidate genes on human chromosome 21

Energy Technology Data Exchange (ETDEWEB)

Sherman, L.S.; Bennett, P.R.; Moore, G.E. [Queen Charlotte`s and Chelsea Hospital, London (United Kingdom)

1994-09-01

Two cases of maternal uniparental (hetero)disomy for human chromosome 21 (mUPD21) have been identified in a systematic search for UPD in 23 cases of early embryonic failure (EEF). Bi-parental origin of the other chromosome pairs was confirmed using specific VNTR probes or dinucleotide repeat analysis. Both maternally and paternally derived isochromosomes 21q have previously been identified in two individuals with normal phenotypes. Full UPD21 has a different mechanism of origin than uniparental isochromosome 21q and its effect on imprinted genes and phenotypic outcome will therefore not necessarily be the same. EEF associated with mUPD21 suggests that developmentally important genes on HSA 21 may be imprinted such that they are only expressed from either the maternally or paternally derived alleles. We have searched for monoallelic expression of candidate genes on HSA 21 in human pregnancy (CBS, IFNAR, COL6A1) using intragenic DNA polymorphisms. These genes were chosen either because their murine homologues lie in imprinted regions or because they are potentially important in embryogenesis. Once imprinted candidate genes have been identified, their methylation status and expression in normal, early embryonic failure and uniparental disomy 21 pregnancies will be studied. At the same time, a larger number of cases of EEF are being examined to further investigate the incidence of UPD21 in this group.

Chromosome segregation regulation in human zygotes : Altered mitotic histone phosphorylation dynamics underlying centromeric targeting of the chromosomal passenger complex

NARCIS (Netherlands)

Van De Werken, C.; Avo Santos, M.; Laven, J. S E; Eleveld, C.; Fauser, B. C J M; Lens, S. M A; Baart, E. B.

2015-01-01

STUDY QUESTION Are the kinase feedback loops that regulate activation and centromeric targeting of the chromosomal passenger complex (CPC), functional during mitosis in human embryos? SUMMARY ANSWER Investigation of the regulatory kinase pathways involved in centromeric CPC targeting revealed normal

Dose Assessment using Chromosome Aberration Analyses in Human Peripheral Blood Lymphocytes

Energy Technology Data Exchange (ETDEWEB)

Ryu, Tae Ho; Kim, Jin-Hong; Kim, Jin Kyu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2015-10-15

The healthy five donors were recruited to establish the dose-response calibration curve for chromosomal aberrations by ionizing radiation exposure. Our cytogenetic results revealed that the mean frequency of chromosome aberration increased with increasing radiation dose. In this study, dicentric assay and CBMN assay were compared considering the sensitivity and accuracy of dose estimation. Therefore, these chromosome aberration analyses will be the foundation for biological dosimetric analysis with additional research methods such as translocation and PCC assay. The conventional analysis of dicentric chromosomes in HPBL was suggested by Bender and Gooch in 1962. This assay has been for many years, the golden standard and the most specific method for ionizing radiation damage. The dicentric assay technique in HPBL has been shown as the most sensitive biological method and reliable bio-indicator of quantifying the radiation dose. In contrast, the micronucleus assay has advantages over the dicentric assay since it is rapid and requires less specialized expertise, and accordingly it can be applied to monitor a big population. The cytokinesis-block micronucleus (CBMN) assay is a suitable method for micronuceli measurement in cultured human as well as mammalian cells. The aim of our study was to establish the dose response curve of radiation-induced chromosome aberrations in HPBL by analyzing the frequency of dicentrics and micronuclei.

New sequence-based data on the relative DNA contents of chromosomes in the normal male and female human diploid genomes for radiation molecular cytogenetics

Directory of Open Access Journals (Sweden)

Repin Mikhail V

2009-06-01

Full Text Available Abstract Background The objective of this work is to obtain the correct relative DNA contents of chromosomes in the normal male and female human diploid genomes for the use at FISH analysis of radiation-induced chromosome aberrations. Results The relative DNA contents of chromosomes in the male and female human diploid genomes have been calculated from the publicly available international Human Genome Project data. New sequence-based data on the relative DNA contents of human chromosomes were compared with the data recommended by the International Atomic Energy Agency in 2001. The differences in the values of the relative DNA contents of chromosomes obtained by using different approaches for 15 human chromosomes, mainly for large chromosomes, were below 2%. For the chromosomes 13, 17, 20 and 22 the differences were above 5%. Conclusion New sequence-based data on the relative DNA contents of chromosomes in the normal male and female human diploid genomes were obtained. This approach, based on the genome sequence, can be recommended for the use in radiation molecular cytogenetics.

Students as "Humans Chromosomes" in Role-Playing Mitosis and Meiosis

Science.gov (United States)

Chinnici, Joseph P.; Yue, Joyce W.; Torres, Kieron M.

2004-01-01

Students often find it challenging to understand mitosis and meiosis and determine their processes. To develop an easier way to understand these terms, students are asked to role-play mitosis and meiosis and students themselves act as human chromosomes, which help students to learn differences between mitosis and meiosis.

Cloning and chromosomal localization of the three human syntrophin genes

Energy Technology Data Exchange (ETDEWEB)

Feener, C.A.; Anderson, M.D.S.; Selig, S. [Children`s Hospital, Boston, MA (United States)] [and others

1994-09-01

Dystrophin, the protein product the Duchenne muscular dystrophy locus, is normally found to be associated with a complex of proteins. Among these dystrophin-associated proteins are the syntrophins, a group of 59 kDa membrane-associated proteins. When the syntrophins are purified based upon their association with dystrophin, they have been shown previously to form two distinct groups, the acidic ({alpha}) and basic ({beta}) forms. Based on peptide and rodent cDNA sequences, three separate syntrophin genes have been cloned and characterized from human tissues. The predicted amino acid sequences from these cDNA reveal that these proteins are related but are distinct with respect to charge, as predicted from their biochemistry. The family consists of one acidic ({alpha}-syntrophin, analogous to mouse syntrophin-1) and two basic ({beta}{sub 1}-syntrophin; and {beta}{sub 2}-syntrophin, analogous to mouse syntrophin-2) genes. Each of the three genes are widely expressed in a variety of human tissues, but the relative abundance of the three are unique with respect to each other. {alpha}-syntrophin is expressed primarily in skeletal muscle and heart as a single transcript. {beta}{sub 1}-syntrophin is expressed widely in up to five distinct transcript sizes, and is most abundant in brain. The human chromosomal locations of the three syntrophins are currently being mapped. {beta}{sub 1}-syntrophin maps to chromosome 8q23-24 and {beta}{sub 2}-syntrophin to chromosome 16. The {alpha}-syntrophin gene will be mapped accordingly. Although all three genes are candidates for neuromuscular diseases, the predominant expression of {alpha}-syntrophin in skeletal muscle and heart makes it a strong candidate to be involved in a neuromuscular disease.

Localization of the homolog of a mouse craniofacial mutant to human chromosome 18q11 and evaluation of linkage to human CLP and CPO

Energy Technology Data Exchange (ETDEWEB)

Griffith, A.J.; Burgess, D.L.; Kohrman, D.C.; Yu, J. [Univ. of Michigan, Ann Arbor, MI (United States)] [and others

1996-06-15

The transgene-induced mutation 9257 and the spontaneous mutation twirler cause craniofacial and inner ear malformations and are located on mouse chromosome 18 near the ataxia locus ax. To map the human homolog of 9257, a probe from the transgene insertion site was used to screen a human genomic library. Analysis of a cross-hybridizing human clone identified a 3-kb conserved sequence block that does not appear to contain protein coding sequence. Analysis of somatic cell hybrid panels assigned the human locus to 18q11. The polymorphic microsatellite markers D18S1001 and D18S1002 were isolated from the human locus and mapped by linkage analysis using the CEPH pedigrees. The 9257 locus maps close to the centromeres of human chromosome 18q and mouse chromosome 18 at the proximal end of a conserved linkage group. To evaluate the role of this locus in human craniofacial disorders, linkage to D18S1002 was tested in 11 families with autosomal dominant nonsyndromic cleft lip and palate and 3 families with autosomal dominant cleft palate only. Obligatory recombinants were observed in 8 of the families, and negative lod scores from the other families indicated that these disorders are not linked to the chromosome 18 loci. 23 refs., 4 figs., 2 tabs.

Clonal chromosomal and genomic instability during human multipotent mesenchymal stromal cells long-term culture.

Directory of Open Access Journals (Sweden)

Victoria Nikitina

Full Text Available Spontaneous mutagenesis often leads to appearance of genetic changes in cells. Although human multipotent mesenchymal stromal cells (hMSC are considered as genetically stable, there is a risk of genomic and structural chromosome instability and, therefore, side effects of cell therapy associated with long-term effects. In this study, the karyotype, genetic variability and clone formation analyses have been carried out in the long-term culture MSC from human gingival mucosa.The immunophenotype of MSC has been examined using flow cytofluorometry and short tandem repeat (STR analysis has been carried out for authentication. The karyotype has been examined using GTG staining and mFISH, while the assessment of the aneuploidy 8 frequency has been performed using centromere specific chromosome FISH probes in interphase cells.The immunophenotype and STR loci combination did not change during the process of cultivation. From passage 23 the proliferative activity of cultured MSCs was significantly reduced. From passage 12 of cultivation, clones of cells with stable chromosome aberrations have been identified and the biggest of these (12% are tetrasomy of chromosome 8. The random genetic and structural chromosomal aberrations and the spontaneous level of chromosomal aberrations in the hMSC long-term cultures were also described.The spectrum of spontaneous chromosomal aberrations in MSC long-term cultivation has been described. Clonal chromosomal aberrations have been identified. A clone of cells with tetrasomy 8 has been detected in passage 12 and has reached the maximum size by passage 18 before and decreased along with the reduction of proliferative activity of cell line by passage 26. At later passages, the MSC line exhibited a set of cells with structural variants of the karyotype with a preponderance of normal diploid cells. The results of our study strongly suggest a need for rigorous genetic analyses of the clone formation in cultured MSCs before

Conserved chromosomal positions of dual domains of the ets protooncogene in cats, mice, and humans

International Nuclear Information System (INIS)

Watson, D.K.; McWilliams-Smith, M.J.; Kozak, C.

1986-01-01

The mammalian protooncogene homologue of the avian v-ets sequence from the E26 retrovirus consists of two sequentially distinct domains located on different chromosomes. Using somatic cell hybrid panels, the authors have mapped the mammalian homologue of the 5' v-ets-domain to chromosome 11 (ETS1) in man, to chromosome 9 (ets-1) in mouse, and to chromosome D1 (ETS1) in the domestic cat. The mammalian homologue of the 3' v-ets domain was similarly mapped to human chromosome 21 (ETS2), to mouse chromosome 16 (Ets-2), and to feline chromosome C2 (ETS2). Both protooncogenes fell in syntenic groups of homologous linked loci that were conserved among the three species. The occurrence of two distinct functional protooncogenes and their conservation of linkage positions in the three mammalian orders indicate that these two genes have been separate since before the evolutionary divergence of mammals

Effect of borax on immune cell proliferation and sister chromatid exchange in human chromosomes

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Pongsavee Malinee

2009-10-01

Full Text Available Abstract Background Borax is used as a food additive. It becomes toxic when accumulated in the body. It causes vomiting, fatigue and renal failure. Methods The heparinized blood samples from 40 healthy men were studied for the impact of borax toxicity on immune cell proliferation (lymphocyte proliferation and sister chromatid exchange in human chromosomes. The MTT assay and Sister Chromatid Exchange (SCE technic were used in this experiment with the borax concentrations of 0.1, 0.15, 0.2, 0.3 and 0.6 mg/ml. Results It showed that the immune cell proliferation (lymphocyte proliferation was decreased when the concentrations of borax increased. The borax concentration of 0.6 mg/ml had the most effectiveness to the lymphocyte proliferation and had the highest cytotoxicity index (CI. The borax concentrations of 0.15, 0.2, 0.3 and 0.6 mg/ml significantly induced sister chromatid exchange in human chromosomes (P Conclusion Borax had effects on immune cell proliferation (lymphocyte proliferation and induced sister chromatid exchange in human chromosomes. Toxicity of borax may lead to cellular toxicity and genetic defect in human.

Computational simulation of chromosome breaks in human liver

International Nuclear Information System (INIS)

Yang Jianshe; Li Wenjian; Jin Xiaodong

2006-01-01

An easy method was established for computing chromosome breaks in cells exposed to heavily charged particles. The cell chromosome break value by 12 C +6 ions was theoretically calculated, and was tested with experimental data of chromosome breaks by using a premature chromosome condensation technique. The theoretical chromosome break value agreed well with the experimental data. The higher relative biological effectiveness of the heavy ions was closely correlated to its physical characteristics. In addition, the chromosome break value can be predicted off line. (authors)

Protective Effect of Curcumin on γ - radiation Induced Chromosome Aberrations in Human Blood Lymphocytes

International Nuclear Information System (INIS)

AlSuhaibani, E.S

2008-01-01

The present work is aimed at evaluating the radioprotective effect of curcumin on γ radiation induced genetic toxicity. The DNA damage was analyzed by the frequencies of chromosome aberrations assay. Human lymphocytes were treated in vitro with 5.0 γg/ml of curcumin for 30 min at 37 degree C then exposed to 1, 2 and 4 Gy gamma-radiation. The lymphocytes which were pre-treated with curcumin exhibited a significant decrease in the frequency of chromosome aberration at 1 and 2 Gy radiation-induced chromosome damage as compared with the irradiated cells which did not receive the curcumin pretreatment. Thus, pretreatment with curcumin gives protection to lymphocytes against γ-radiation induced chromosome aberration at certain doses. (author)

Chromosomal instability can be induced by the formation of breakage-prone chromosome rearrangement junctions

International Nuclear Information System (INIS)

Allen, R.N.; Ritter, L.; Moore, S.R.; Grosovsky, A.J.

2003-01-01

Full text: Studies in our lab have led to the hypothesis that chromosomal rearrangements can generate novel breakage-prone sites, resulting in chromosomal instability acting predominantly in cis. For example, specific breakage of large blocks of centromeric region heterochromatin on chromosome 16q by treatment with 2,6-diaminopurine (DAP) is associated with repeated rearrangement of chromosome 16q during outgrowth of DAP-treated clones, thereby establishing a link between the initial site of damage and the occurrence of persistent chromosomal instability. Similarly, karyotypic analysis of gamma ray induced instability demonstrated that chromosomal rearrangements in sub-clones were significantly clustered near the site of previously identified chromosomal rearrangement junctions in unstable parental clones. This study investigates the hypothesis that integration of transfected sequences into host chromosomes could create breakage-prone junction regions and persistent genomic instability without exposure to DNA-damage agents. These junctions may mimic the unstable chromosomal rearrangements induced by DAP or radiation, and thus provide a test of the broader hypothesis that instability can to some extent be attributed to the formation of novel chromosomal breakage hot spots. These experiments were performed using human-hamster hybrid AL cells containing a single human chromosome 11, which was used to monitor instability in a chromosomal painting assay. AL cells were transfected with a 2.5 Kb fragment containing multiple copies of the 180 bp human alpha heterochromatic repeat, which resulted in chromosomal instability in 41% of the transfected clones. Parallel exposure to gamma-radiation resulted in a similar level of chromosomal instability, although control transfections with plasmid alone did not lead to karyotypic instability. Chromosomal instability induced by integration of alpha heterochromatic repeats was also frequently associated with delayed reproductive

Use of M-FISH analysis of α-particle-induced chromosome aberrations for the assessment of chromosomal breakpoint distribution and complex aberration formation

International Nuclear Information System (INIS)

Anderson, R.M.; Sumption, N.D.; Papworth, D.G.; Goodhead, D.T.

2003-01-01

Double strand breaks (dsb) of varying complexity are an important class of damage induced after exposure to ionising radiation and are considered to be the critical lesion for the formation of radiation-induced chromosome aberrations. Assuming the basic principles of the 'Breakage and Reunion' theory, dsb represent 'breakage' and aberrations are produced from the illegitimate repair (reunion) of the resulting dsb free-'ends'. Numerous questions relate to this process, in particular, (1) do chromosomal breakpoint 'hot-spots' that represent sensitive sites for breakage and/or regions of preferential repair/mis-repair, exist? (2) Considering that individual chromosomes and chromosome regions occupy discrete territories in the interphase nucleus, could rearrangements between specific chromosomes reflect domain organisation at the time of damage? (3) Assuming the topological constraints imposed on chromatin are not dramatically influenced by the presence of dsb, then how do multiple 'ends' from different chromosomes proximally associate for mis-repair as complex chromosome aberrations? To address these questions, we have analysed the chromosome aberrations induced in peripheral blood lymphocytes after exposure to 0.5 Gy α -particles (mean of 1 α -particle/cell) using the technique of M-FISH. This technique 'paints' all the human chromosomes (excluding homologues) uniquely, allowing chromosomal mis-repair to be visualised as differential colour-junctions and in addition, enhanced DAPI banding enables gross breakpoint assignation of these colour junctions. To test for non-randomness, we are comparing the frequency of occurrence of breakpoints obtained up to now with the F98 glioma model our knowledbased on chromosome length. Similarly, the involvement of each chromosome relative to other chromosomes within individual rearrangements can be determined by assuming the volume of chromosome domains is also proportional to their length. The current data to be presented will

Chromosome Connections: Compelling Clues to Common Ancestry

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Flammer, Larry

2013-01-01

Students compare banding patterns on hominid chromosomes and see striking evidence of their common ancestry. To test this, human chromosome no. 2 is matched with two shorter chimpanzee chromosomes, leading to the hypothesis that human chromosome 2 resulted from the fusion of the two shorter chromosomes. Students test that hypothesis by looking for…

Chromosomal Aberrations in Canine Gliomas Define Candidate Genes and Common Pathways in Dogs and Humans

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York, Dan; Higgins, Robert J.; LeCouteur, Richard A.; Joshi, Nikhil; Bannasch, Danika

2016-01-01

Spontaneous gliomas in dogs occur at a frequency similar to that in humans and may provide a translational model for therapeutic development and comparative biological investigations. Copy number alterations in 38 canine gliomas, including diffuse astrocytomas, glioblastomas, oligodendrogliomas, and mixed oligoastrocytomas, were defined using an Illumina 170K single nucleotide polymorphism array. Highly recurrent alterations were seen in up to 85% of some tumor types, most notably involving chromosomes 13, 22, and 38, and gliomas clustered into 2 major groups consisting of high-grade IV astrocytomas, or oligodendrogliomas and other tumors. Tumor types were characterized by specific broad and focal chromosomal events including focal loss of the INK4A/B locus in glioblastoma and loss of the RB1 gene and amplification of the PDGFRA gene in oligodendrogliomas. Genes associated with the 3 critical pathways in human high-grade gliomas (TP53, RB1, and RTK/RAS/PI3K) were frequently associated with canine aberrations. Analysis of oligodendrogliomas revealed regions of chromosomal losses syntenic to human 1p involving tumor suppressor genes, such as CDKN2C, as well as genes associated with apoptosis, autophagy, and response to chemotherapy and radiation. Analysis of high frequency chromosomal aberrations with respect to human orthologues may provide insight into both novel and common pathways in gliomagenesis and response to therapy. PMID:27251041

A scale invariant clustering of genes on human chromosome 7

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Kendal Wayne S

2004-01-01

Full Text Available Abstract Background Vertebrate genes often appear to cluster within the background of nontranscribed genomic DNA. Here an analysis of the physical distribution of gene structures on human chromosome 7 was performed to confirm the presence of clustering, and to elucidate possible underlying statistical and biological mechanisms. Results Clustering of genes was confirmed by virtue of a variance of the number of genes per unit physical length that exceeded the respective mean. Further evidence for clustering came from a power function relationship between the variance and mean that possessed an exponent of 1.51. This power function implied that the spatial distribution of genes on chromosome 7 was scale invariant, and that the underlying statistical distribution had a Poisson-gamma (PG form. A PG distribution for the spatial scattering of genes was validated by stringent comparisons of both the predicted variance to mean power function and its cumulative distribution function to data derived from chromosome 7. Conclusion The PG distribution was consistent with at least two different biological models: In the microrearrangement model, the number of genes per unit length of chromosome represented the contribution of a random number of smaller chromosomal segments that had originated by random breakage and reconstruction of more primitive chromosomes. Each of these smaller segments would have necessarily contained (on average a gamma distributed number of genes. In the gene cluster model, genes would be scattered randomly to begin with. Over evolutionary timescales, tandem duplication, mutation, insertion, deletion and rearrangement could act at these gene sites through a stochastic birth death and immigration process to yield a PG distribution. On the basis of the gene position data alone it was not possible to identify the biological model which best explained the observed clustering. However, the underlying PG statistical model implicated neutral

Mapping of the human NMDA receptor subunit (NMDAR1) and the proposed NMDA receptor glutamate-binding subunit (NMDARA1) to chromosomes 9q34.3 and chromosome 8, respectively

DEFF Research Database (Denmark)

Collins, C; Duff, C; Duncan, A M

1993-01-01

to human chromosome 8 using a somatic cell hybrid panel. Because the gene causing HD has been localized to chromosome 4p16.3, the chromosome assignments reported here are inconsistent with either of these genes playing a causative role in the molecular pathology of HD. However, it is noteworthy......A role for the N-methyl-D-aspartate (NMDA) receptor in the molecular pathology underlying Huntington disease (HD) has been proposed on the basis of neurochemical studies in HD and the ability of the NMDA receptor to mediate neuronal cell death. The molecular cloning of the human NMDA receptor...

Chromosome heteromorphisms in the Japanese, 3

International Nuclear Information System (INIS)

Sofuni, Toshio; Awa, A.A.

1982-12-01

The type and frequency of chromosome variants detected by the C-staining method were ascertained in 1,857 individuals residing in Hiroshima. The most frequent heteromorphic variant was the total inversion of the C-band in chromosome 9 found in 27 individuals (1.45%). The total inversion of the C-band in chromosome 1 was not seen in this sample, but the partial inversion of the C-band in chromosome 1 was found in 18 persons (0.97%). Partial inversion was also detected in the C-band in chromosome 9 in 22 individuals (1.18%). In chromosome 16, neither total nor partial inversion of the C-band was observed in the present study. The frequencies of chromosomes 1, 9, and 16 with a very large C-band were 0.70%, 0.22%, and 0.54%, respectively. Aside from these (1, 9, and 16) a very large C-band was found occasionally in chromosomes 4, 5, 6, 11, 12, 14, and 15, and an unusual insertion of the Y chromosome was observed. A total of 128 C-band variants (6.89%) was found in the 1,857 Hiroshima residents. (author)

Qualitative and quantitative expression status of the human chromosome 20 genes in cancer tissues and the representative cell lines.

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Wang, Quanhui; Wen, Bo; Yan, Guangrong; Wei, Junying; Xie, Liqi; Xu, Shaohang; Jiang, Dahai; Wang, Tingyou; Lin, Liang; Zi, Jin; Zhang, Ju; Zhou, Ruo; Zhao, Haiyi; Ren, Zhe; Qu, Nengrong; Lou, Xiaomin; Sun, Haidan; Du, Chaoqin; Chen, Chuangbin; Zhang, Shenyan; Tan, Fengji; Xian, Youqi; Gao, Zhibo; He, Minghui; Chen, Longyun; Zhao, Xiaohang; Xu, Ping; Zhu, Yunping; Yin, Xingfeng; Shen, Huali; Zhang, Yang; Jiang, Jing; Zhang, Chengpu; Li, Liwei; Chang, Cheng; Ma, Jie; Yan, Guoquan; Yao, Jun; Lu, Haojie; Ying, Wantao; Zhong, Fan; He, Qing-Yu; Liu, Siqi

2013-01-04

Under the guidance of the Chromosome-centric Human Proteome Project (C-HPP), (1, 2) we conducted a systematic survey of the expression status of genes located at human chromosome 20 (Chr.20) in three cancer tissues, gastric, colon, and liver carcinoma, and their representative cell lines. We have globally profiled proteomes in these samples with combined technology of LC-MS/MS and acquired the corresponding mRNA information upon RNA-seq and RNAchip. In total, 323 unique proteins were identified, covering 60% of the coding genes (323/547) in Chr.20. With regards to qualitative information of proteomics, we overall evaluated the correlation of the identified Chr.20 proteins with target genes of transcription factors or of microRNA, conserved genes and cancer-related genes. As for quantitative information, the expression abundances of Chr.20 genes were found to be almost consistent in both tissues and cell lines of mRNA in all individual chromosome regions, whereas those of Chr.20 proteins in cells are different from tissues, especially in the region of 20q13.33. Furthermore, the abundances of Chr.20 proteins were hierarchically evaluated according to tissue- or cancer-related distribution. The analysis revealed several cancer-related proteins in Chr.20 are tissue- or cell-type dependent. With integration of all the acquired data, for the first time we established a solid database of the Chr.20 proteome.

Regional assignment of seven genes on chromosome 1 of man by use of man-Chinese hamster somatic cell hybrids. I. Results obtained after hybridization of human cells carrying reciprocal translocations involving chromosome 1.

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Jongsma, A P; Burgerhout, W G

1977-01-01

Regional localization studies of genes coding for human PGD, PPH1, PGM1, UGPP, GuK1, Pep-C, and FH, which have been assigned to chromosome 1, were performed with man-Chinese hamster somatic cell hybrids, Informative hybrids that retained fragments of the human chromosome 1 were produced by fusion of hamster cells with human cells carrying reciprocal translocations involving chromosome 1. Analysis of the hybrids that retained one of the translocation chromosomes or de novo rearrangements involving the human 1 revealed the following gene positions: PGD and PPH1 in 1pter leads to 1p32, PGM1 in 1p32 leads to 1p22, UGPP and GuK1 in 1q21 leads to 1q42, FH in 1qter leads to 1q42, and Pep-C probably in 1q42.

Pericentric Inversion of Human Chromosome 9 Epidemiology Study in Czech Males and Females.

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Šípek, A; Panczak, A; Mihalová, R; Hrčková, L; Suttrová, E; Sobotka, V; Lonský, P; Kaspříková, N; Gregor, V

2015-01-01

Pericentric inversion of human chromosome 9 [inv(9)] is a relatively common cytogenetic finding. It is largely considered a clinically insignificant variant of the normal human karyotype. However, numerous studies have suggested its possible association with certain pathologies, e.g., infertility, habitual abortions or schizophrenia. We analysed the incidence of inv(9) and the spectrum of clinical indications for karyotyping among inv(9) carriers in three medical genetics departments in Prague. In their cytogenetic databases, among 26,597 total records we identified 421 (1.6 %) cases of inv(9) without any concurrent cytogenetic pathology. This study represents the world's largest epidemiological study on inv(9) to date. The incidence of inv(9) calculated in this way from diagnostic laboratory data does not differ from the incidence of inv(9) in three specific populationbased samples of healthy individuals (N = 4,166) karyotyped for preventive (amniocentesis for advanced maternal age, gamete donation) or legal reasons (children awaiting adoption). The most frequent clinical indication in inv(9) carriers was "idiopathic reproductive failure" - 37.1 %. The spectra and percentages of indications in individuals with inv(9) were further statistically evaluated for one of the departments (N = 170) by comparing individuals with inv(9) to a control group of 661 individuals with normal karyotypes without this inversion. The proportion of clinical referrals for "idiopathic reproductive failure" among inv(9) cases remains higher than in controls, but the difference is not statistically significant for both genders combined. Analysis in separated genders showed that the incidence of "idiopathic reproductive failure" could differ among inv(9) female and male carriers.

Human Chromosome 21: Mapping of the chromosomes and cloning of cDNAs

Energy Technology Data Exchange (ETDEWEB)

Antonarakis, S.E.

1991-09-01

The objective of the research funded by DOE grant DE-FG02-89ER60857 from 6/15/89 to 8/31/91 was to contribute to the physical mapping of human chromosome 21 (HC21) by cloning large fragments of DNA into Yeast Artificial Chromosomes (YACs) and identify YACs that map on HC21. A total of 54 sequence tagged sites (STS) have been developed and mapped in our laboratory to HC21 and can be used as initial reference points for YAC identification and construction of overlapping clones. A small YAC library was constructed which is HC21 specific. DNA from somatic cell hybrid WAV17 or from flow-sorted HC21 was partially digested with EcoRI, ligated into vectors PJS97, PJS98, and YACs have been obtained with average size insert of more than 300 kb. This library has been deposited in D. Patterson's lab for the Joint YAC screening effort. Additional YAC libraries from ICI Pharmaceuticals or from Los Alamos National Laboratories have been screened with several STS and positive YACs have been identified. Work in progress includes screening of YAC libraries in order to construct overlapping clones, characterization of the cloning ends of YACs, characterization of additional STS and cloning of HC21 specific cDNAs. 15 refs., 2 figs., 5 tabs.

Inter-chromosomal heterogeneity in the formation of radiation induced chromosomal aberrations

International Nuclear Information System (INIS)

Natarajan, A.T.; Vermeulen, S.; Boei, J.J.W.A.

1997-01-01

It is generally assumed that radiation induced chromosomal lesions are distributed randomly and repaired randomly among the genome. Recent studies using fluorescent in situ hybridization (FISH) and chromosome specific DNA libraries indicate that some chromosomes are more sensitive for radiation induced aberration formation than others. Chromosome No. 4 in human and chromosome No. 8 in Chinese hamster have been found to involve more in exchange aberrations than others, when calculated on the basis of their DNA content. Painting with arm specific chromosome libraries indicate that the frequencies of radiation induced intra-chromosome exchanges (i.e., between the arms of a chromosome, such as centric rings and inversions) are far in excess than one would expect on the basis of the frequencies of observed inter-chromosomal exchanges. The possible factors leading to the observed heterogeneity will be discussed

Analysis of the conservation of synteny between Fugu and human chromosome 12

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Koop Ben F

2003-07-01

Full Text Available Abstract Background The pufferfish Fugu rubripes (Fugu with its compact genome is increasingly recognized as an important vertebrate model for comparative genomic studies. In particular, large regions of conserved synteny between human and Fugu genomes indicate its utility to identify disease-causing genes. The human chromosome 12p12 is frequently deleted in various hematological malignancies and solid tumors, but the actual tumor suppressor gene remains unidentified. Results We investigated approximately 200 kb of the genomic region surrounding the ETV6 locus in Fugu (fETV6 in order to find conserved functional features, such as genes or regulatory regions, that could give insight into the nature of the genes targeted by deletions in human cancer cells. Seven genes were identified near the fETV6 locus. We found that the synteny with human chromosome 12 was conserved, but extensive genomic rearrangements occurred between the Fugu and human ETV6 loci. Conclusion This comparative analysis led to the identification of previously uncharacterized genes in the human genome and some potentially important regulatory sequences as well. This is a good indication that the analysis of the compact Fugu genome will be valuable to identify functional features that have been conserved throughout the evolution of vertebrates.

Cell killing and chromosomal aberration induced by heavy-ion beams in cultured human tumor cells

International Nuclear Information System (INIS)

Takakura, K.; Funada, A.; Mohri, M.; Lee, R.; Aoki, M.; Furusawa, Y.; Gotoh, E.

2003-01-01

Full text: To clarify the relation between cell death and chromosomal aberration in cultured human tumor cells irradaited with heavy-ion beams. The analyses were carried out on the basis of the linear energy transfer (LET) values of heavy ion beams as radiation source. Exponentially growing human tumor cells, Human Salivary Gland Tumor cells (HSG cells), were irradiated with various high energy heavy ions, such as 13 keV/micrometer carbon (C) ions as low LET charged particle radiation source, 120 keV/ micrometer carbon (C) ions and 440 keV/micrometer iron (Fe) ions as high LET charged particle radiation sources.The cell death was analysed by the colony formation method, and the chromosomal aberration and its repairing kinetics was analysed by prematurely chromosome condensation method (PCC method) using calyculin A. Chromatid-type breaks, isochromatid breaks and exchanges were scored for the samples from the cells keeping with various incubation time after irradiation. The LET dependence of the cell death was similar to that of the chromosome exchange formation after 12 hours incubation. A maximum peak was around 120 keV/micrometer. However it was not similar to the LET dependence of isochromatid breaks or chromatid breaks after 12 hours incubation. These results suggest that the exchanges formed in chromosome after irradiation should be one of essential causes to lead the cell death. The different quality of induced chromosome damage between high-LET and low-LET radiation was also shown. About 89 % and 88 % chromatid breaks induced by X rays and 13 keV/micrometer C ions were rejoined within 12 hours of post-irradiation, though only 71% and 58 % of chromatid breaks induced by 120 keV/micrometer C ions and 440 keV/micrometer Fe ions were rejoined within 12 hours of post-irradiation

Cytogenetic and molecular genetic characterization of immortalized human ovarian surface epithelial cell lines: consistent loss of chromosome 13 and amplification of chromosome 20.

Science.gov (United States)

Jin, Yuesheng; Zhang, Hao; Tsao, Sai Wah; Jin, Charlotte; Lv, Mei; Strömbeck, Bodil; Wiegant, Joop; Wan, Thomas Shek Kong; Yuen, Po Wing; Kwong, Yok-Lam

2004-01-01

This study aimed at identifying the genetic events involved in immortalization of ovarian epithelial cells, which might be important steps in ovarian carcinogenesis. The genetic profiles of five human ovarian surface epithelial (HOSE) cell lines immortalized by retroviral transfection of the human papillomavirus (HPV) E6/E7 genes were thoroughly characterized by chromosome banding and fluorescence in situ hybridization (FISH), at various passages pre- and post-crisis. In pre-crisis, most cells had simple, non-clonal karyotypic changes. Telomere association was the commonest aberration, suggesting that tolermase dysfunction might be an important genetic event leading to cellular crisis. After immortalization post-crisis, however, the karyotypic patterns were non-random. Loss of genetic materials was a characteristic feature. The commonest numerical aberrations were -13, -14, -16, -17, -18, and +5. Among them, loss of chromosome 13 was common change observed in all lines. The only recurrent structural aberration was homogeneously staining regions (hsr) observed in three lines. FISH and combined binary ratio labeling (COBRA)-FISH showed in two cases that the hsrs were derived from chromosome 20. Clonal evolution was observed in four of the lines. In one line, hsr was the only change shared by all subclones, suggesting that it might be a primary event in cell immortalization. The results of the present study suggested that loss of chromosome 13 and the amplification of chromosome 20 might be early genetic events involved in ovarian cell immortalization, and might be useful targets for the study of genomic aberrations in ovarian carcinogenesis.

Human X chromosome inactivation and reactivation: implications for cell reprogramming and disease.

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Cantone, Irene; Fisher, Amanda G

2017-11-05

X-chromosome inactivation (XCI) is an exemplar of epigenetic regulation that is set up as pluripotent cells differentiate. Once established, XCI is stably propagated, but can be reversed in vivo or by pluripotent reprogramming in vitro Although reprogramming provides a useful model for inactive X (Xi) reactivation in mouse, the relative instability and heterogeneity of human embryonic stem (ES) cells and induced pluripotent stem cells hampers comparable progress in human. Here we review studies aimed at reactivating the human Xi using different reprogramming strategies. We outline our recent results using mouse ES cells to reprogramme female human fibroblasts by cell-cell fusion. We show that pluripotent reprogramming induces widespread and rapid chromatin remodelling in which the human Xi loses XIST and H3K27m3 enrichment and selected Xi genes become reactivated, ahead of mitotic division. Using RNA sequencing to map the extent of human Xi reactivation, and chromatin-modifying drugs to potentiate reactivation, we outline how this approach could be used to better design strategies to re-express human X-linked loci. As cell fusion induces the expression of human pluripotency genes that represent both the 'primed' and 'naive' states, this approach may also offer a fresh opportunity to segregate human pluripotent states with distinct Xi expression profiles, using single-cell-based approaches.This article is part of the themed issue 'X-chromosome inactivation: a tribute to Mary Lyon'. © 2017 The Author(s).

Cytogenetic biological dosimetry in radiological protection: chromosome aberration analysis in human lymphocyties

International Nuclear Information System (INIS)

Campos, I.M.A. de.

1988-01-01

The effects of ionizing radiation on chromosomes have been know for several decades and dose effect relationships are also fairly well established for several doses and dose rates. Apart from its biological significance, the interpretation of chromosome aberration frequency associated with human exposure to radiation plays an important role in dose assessment, particularly in cases where exposure is though to have occurred but no physical dose monitoring system was present. Based on the cytogenetic data obtained from seven cases of exposure to radiation the aberration frequency have been fitted to the quadratic function Y= αD + βD 2 as the dose response curves from literature. The dose equivalent estimate by frequency of chromosomic aberration found here was compared with 60 Co and 192 Ir already published curves obtained at almost similar dose rate together with some hematological data. (author) [pt

European gene mapping project (EUROGEM) : Breakpoint panels for human chromosomes based on the CEPH reference families

NARCIS (Netherlands)

Attwood, J; Bryant, SP; Bains, R; Povey, R; Povey, S; Rebello, M; Kapsetaki, M; Moschonas, NK; Grzeschik, KH; Otto, M; Dixon, M; Sudworth, HE; Kooy, RF; Wright, A; Teague, P; Terrenato, L; Vergnaud, G; Monfouilloux, S; Weissenbach, J; Alibert, O; Dib, C; Faure, S; Bakker, E; Pearson, NM; Vossen, RHAM; Gal, A; MuellerMyhsok, B; Cann, HM; Spurr, NK

Meiotic breakpoint panels for human chromosomes 2, 3, 4, 5, 6, 7, 8, 9, 10, 13, 14, 15, 17; 18, 20 and X were constructed from genotypes from the CEPH reference families. Each recombinant chromosome included has a breakpoint well-supported with reference to defined quantitative criteria. The panels

Gamma-ray mutagenesis studies in a new human-hamster hybrid, A(L)CD59(+/-), which has two human chromosomes 11 but is hemizygous for the CD59 gene

Science.gov (United States)

Kraemer, S. M.; Vannais, D. B.; Kronenberg, A.; Ueno, A.; Waldren, C. A.; Chatterjee, A. (Principal Investigator)

2001-01-01

Kraemer, S. M., Vannais, D. B., Kronenberg, A., Ueno, A. and Waldren, C. A. Gamma-Ray Mutagenesis Studies in a New Human-Hamster Hybrid, A(L)CD59(+/-), which has Two Human Chromosomes 11 but is Hemizygous for the CD59 Gene. Radiat. Res. 156, 10-19 (2001).We have developed a human-CHO hybrid cell line, named A(L)CD59(+/-), which has two copies of human chromosome 11 but is hemizygous for the CD59 gene and the CD59 cell surface antigen that it encodes. Our previous studies used the A(L) and A(L)C hybrids that respectively contain one or two sets of CHO chromosomes plus a single copy of human chromosome 11. The CD59 gene at 11p13.5 and the CD59 antigen encoded by it are the principal markers used in our mutagenesis studies. The hybrid A(L)CD59(+/-) contains two copies of human chromosome 11, only one of which carries the CD59 gene. The incidence of CD59 (-) mutants (formerly called S1(-)) induced by (137)Cs gamma rays is about fivefold greater in A(L)CD59(+/-) cells than in A(L) cells. Evidence is presented that this increase in mutant yield is due to the increased induction of certain classes of large chromosomal mutations that are lethal to A(L) cells but are tolerated in the A(L)CD59(+/-) hybrid. In addition, significantly more of the CD59 (-) mutants induced by (137)Cs gamma rays in A(L)CD59(+/-) cells display chromosomal instability than in A(L) cells. On the other hand, the yield of gamma-ray-induced CD59 (-) mutants in A(L)CD59(+/-) cells is half that of the A(L)C hybrid, which also tolerates very large mutations but has only one copy of human chromosome 11. We interpret the difference in mutability as evidence that repair processes involving the homologous chromosomes 11 play a role in determining mutant yields. The A(L)CD59(+/-) hybrid provides a useful new tool for quantifying mutagenesis and shedding light on mechanisms of genetic instability and mutagenesis.

HACking the centromere chromatin code: insights from human artificial chromosomes.

Science.gov (United States)

Bergmann, Jan H; Martins, Nuno M C; Larionov, Vladimir; Masumoto, Hiroshi; Earnshaw, William C

2012-07-01

The centromere is a specialized chromosomal region that serves as the assembly site of the kinetochore. At the centromere, CENP-A nucleosomes form part of a chromatin landscape termed centrochromatin. This chromatin environment conveys epigenetic marks regulating kinetochore formation. Recent work sheds light on the intricate relationship between centrochromatin state, the CENP-A assembly pathway and the maintenance of centromere function. Here, we review the emerging picture of how chromatin affects mammalian kinetochore formation. We place particular emphasis on data obtained from Human Artificial Chromosome (HAC) biology and the targeted engineering of centrochromatin using synthetic HACs. We discuss implications of these findings, which indicate that a delicate balance of histone modifications and chromatin state dictates both de novo centromere formation and the maintenance of centromere identity in dividing cell populations.

Radiation-induced genomic instability driven by de novo chromosomal rearrangement hot spots

International Nuclear Information System (INIS)

Grosovsky, A.J.; Allen, R.N.; Moore, S.R.

2003-01-01

Genomic instability has become generally recognized as a critical contributor to tumor progression by generating the necessary number of genetic alterations required for expression of a clinically significant malignancy. Our study of chromosomal instability investigates the hypothesis that chromosomal rearrangements can generate novel breakage-prone sites, resulting in instability acting predominantly in cis. Here we present an analysis of the karyotypic distribution of instability associated chromosomal rearrangements in TK6 and derivative human lymphoblasts. Karyotypic analysis performed on a total of 455 independent clones included 183 rearrangements distributed among 100 separate unstable clones. The results demonstrate that the breakpoints of chromosomal rearrangements in unstable clones are non-randomly distributed throughout the genome. This pattern is statistically significant, and incompatible with expectations for random breakage associated with loss or alteration of a trans-acting factor. Furthermore, specific chromosomal breakage hot spots associated with instability have been identified; these occur in several independent unstable clones and are often repeatedly broken and rejoined during the outgrowth of an individual clone. In complimentary studies, genomic instability was generated without any exposure to a DNA-damaging agent, but rather by transfection with alpha heterochromatin DNA. In a prospective analysis, human-hamster hybrid AL cells containing a single human chromosome 11 were transfected with heterochromatic alpha DNA repeats and clones were analyzed by chromosome 11 painting. Transfection with alpha DNA was associated with karyotypic heterogeneity in 40% of clones examined; control transfections with plasmid alone did not lead to karyotypic heterogeneity

Convergence and divergence of tumor-suppressor and proto-oncogenes in chimpanzee from human chromosome 17

Energy Technology Data Exchange (ETDEWEB)

Verma, R.S.; Ramesh, K.H. [Long Island College Hospital, Brooklyn, NY (United States)

1994-09-01

Due to the emergence of molecular technology, the phylogenetic evolution of the human genome via apes has become a saltatory even. In the present investigation, cosmid probes for P53, Charcot-Marie-Tooth [CMTIA], HER-2/NEU and myeloperoxidase [MPO] were used. Probes mapping to these genetic loci are well-defined on human chromosome 17 [HSA 17]. We localized these genes on chimpanzee [Pan troglodyte] chromosomes by FISH technique employing two different cell lines. Our results indicate that chimpanzee chromosome 19 [PTR 19] differs from HSA 17 by a pericentric inversion. The P53 gene assigned to HSA 17p13.1 is localized on PTR 19p15 and the MPO sequence of HSA 17q21.3-23 hybridized to PTR 19q23. Perplexing enough, HER-2/NEU assigned to HSA 17q11.2 localized to PTR 19p12. Obviously, there is convergence of P53 and MPO regions and distinctive divergence of HER-2/NEU and CMT1A regions of human and chimpanzee. This investigation has demonstrated the pronounced genetic shuffling which occurred during the origin of HSA 17. Molecular markers should serve as evolutionary punctuations in defining the precise sequence of genetic events that led to the evolution of other chromosomes whose genomic synteny, although similar, have surprisingly evolved through different mechanisms.

High-speed AFM of human chromosomes in liquid

Energy Technology Data Exchange (ETDEWEB)

Picco, L M; Dunton, P G; Ulcinas, A; Engledew, D J; Miles, M J [H H Wills Physics Laboratory and IRC in Nanotechnology, University of Bristol, Tyndall Avenue, Bristol BS8 1TL (United Kingdom); Hoshi, O; Ushiki, T [Division of Microscopic Anatomy and Bio-Imaging, Department of Cellular Function, Niigata University Graduate School of Medical and Dental Sciences, Asahimachi-Dori 1, Niigata, 951-8150 (Japan)], E-mail: m.j.miles@bristol.ac.uk

2008-09-24

Further developments of the previously reported high-speed contact-mode AFM are described. The technique is applied to the imaging of human chromosomes at video rate both in air and in water. These are the largest structures to have been imaged with high-speed AFM and the first imaging in liquid to be reported. A possible mechanism that allows such high-speed contact-mode imaging without significant damage to the sample is discussed in the context of the velocity dependence of the measured lateral force on the AFM tip.

High-resolution YAC-cosmid-STS map of human chromosome 13.

Science.gov (United States)

Cayanis, E; Russo, J J; Kalachikov, S; Ye, X; Park, S H; Sunjevaric, I; Bonaldo, M F; Lawton, L; Venkatraj, V S; Schon, E; Soares, M B; Rothstein, R; Warburton, D; Edelman, I S; Zhang, P; Efstratiadis, A; Fischer, S G

1998-01-01

We have assembled a high-resolution physical map of human chromosome 13 DNA (approximately 114 Mb) from hybridization, PCR, and FISH mapping data using a specifically designed set of computer programs. Although the mapping of 13p is limited, 13q (approximately 98 Mb) is covered by an almost continuous contig of 736 YACs aligned to 597 contigs of cosmids. Of a total of 10,789 cosmids initially selected from a chromosome 13-specific cosmid library (16,896 colonies) using inter-Alu PCR probes from the YACs and probes for markers mapped to chromosome 13, 511 were assembled in contigs that were established from cross-hybridization relationships between the cosmids. The 13q YAC-cosmid map was annotated with 655 sequence tagged sites (STSs) with an average spacing of 1 STS per 150 kb. This set of STSs, each identified by a D number and cytogenetic location, includes database markers (198), expressed sequence tags (93), and STSs generated by sequencing of the ends of cosmid inserts (364). Additional annotation has been provided by positioning 197 cosmids mapped by FISH on 13q. The final (comprehensive) map, a list of STS primers, and raw data used in map assembly are available at our Web site (genome1.ccc.columbia.edu/ approximately genome/) and can serve as a resource to facilitate accurate localization of additional markers, provide substrates for sequencing, and assist in the discovery of chromosome 13 genes associated with hereditary diseases.

Genealogical and evolutionary inference with the human Y chromosome.

Science.gov (United States)

Stumpf, M P; Goldstein, D B

2001-03-02

Population genetics has emerged as a powerful tool for unraveling human history. In addition to the study of mitochondrial and autosomal DNA, attention has recently focused on Y-chromosome variation. Ambiguities and inaccuracies in data analysis, however, pose an important obstacle to further development of the field. Here we review the methods available for genealogical inference using Y-chromosome data. Approaches can be divided into those that do and those that do not use an explicit population model in genealogical inference. We describe the strengths and weaknesses of these model-based and model-free approaches, as well as difficulties associated with the mutation process that affect both methods. In the case of genealogical inference using microsatellite loci, we use coalescent simulations to show that relatively simple generalizations of the mutation process can greatly increase the accuracy of genealogical inference. Because model-free and model-based approaches have different biases and limitations, we conclude that there is considerable benefit in the continued use of both types of approaches.

Analyses of prevalence and polymorphisms of six replication-competent and chromosomally assigned porcine endogenous retroviruses in individual pigs and pig subspecies

International Nuclear Information System (INIS)

Niebert, Marcus; Toenjes, Ralf R.

2003-01-01

As porcine endogenous retroviruses (PERV) productively infect human cells in vitro, they pose a serious risk in xenotransplantation and xenogeneic cell therapies. We have analyzed the prevalence of six well-characterized full-length PERV, five of them being replication-competent and four of them being chromosomally assigned (J. Virol. 75 (2001) 5465; J. Virol. 76 (2002) 2714). These analyses revealed a heterogeneous distribution of PERV among individuals and, as no PERV is present in every pig, it seems feasible to generate pigs free of functional PERV by conventional breeding. Conversely, as PERV are polymorphic, single proviruses may have escaped detection and this kind of assay must be performed for every herd used in xenotransplantation or xenogeneic cell therapies. In addition, specific proviruses show internal point mutations which significantly affect their replicational capacities. As there are two different types of PERV LTR structures showing varying levels of transcriptional capacity (J. Virol. 75 (2001) 6933), an analysis of 21 distinct chromosomal locations revealed that PERV which harbor highly active LTRs with repeat elements in U3 are dominant

Computer-assisted detection of chromosomal aberrations for the purpose of establishing a biological dosimeter

International Nuclear Information System (INIS)

Ueberreiter, B.

1982-01-01

Using a special high-resolution microscopy apparatus, digital light microscope images of human chromosomes were generated, and specific image processing algorithms were developed. The pattern recognition process for computer-assisted detection of specific, radiation-induced chromosomal aberrations comprises three steps: First, the orientation of the segmented objects is defined and corrected. For date reduction purposes, the individual chromosomes are reduced to a few basic types containing typical information. After a linear transformation step, the characteristic parameters thus derived form a parameter vector for statistical classification. The method was well suited for distinguishing normal chromosomes from chromosomal aberrations. 94% of the objects were identified correctly. To achieve even higher accuracy, quality standards were set by which suspectedly misclassified objects can be re-investigated in dialog by the human observer. Implementation of the program system for parameter extraction on a fast polyprocessor system opens up a realistic chance of reducing the computing time for dose estimates to about one hour. (orig./MG) [de

The use of unstable chromosome aberrations and micronuclei in the individual biomonitoring: a comparative study

International Nuclear Information System (INIS)

Fernandes, Thiago de Salazar e

2005-02-01

Biodosimetry is based on the investigation of radioinduced biological effects in order to correlate them with the absorbed dose. The quantification of unstable chromosome aberrations and micronuclei, in peripheral blood lymphocytes, are two methods commonly used in biodosimetry. In this context, the aim of this research was to compare these methods in the biomonitoring of health care professionals occupationally exposed to ionizing radiation. In parallel, the technique of C-banding was evaluated for quality control of unstable chromosome aberrations analyses. Thus, samples of peripheral blood from health care professionals of three hospitals from Recife (Brazil) were collected, and the lymphocytes cultures were carried out based on the cytogenetic classical technique. It was pointed out that analysis of micronuclei is faster than the unstable chromosome aberrations ones, which suggests the use of the former in preliminary evaluation in cases of suspected accidental exposure. C-banding technique was efficient, as confirmatory test, in the identification of dicentrics and rings during the analyses of unstable chromosome aberrations, being able to be applied in the quality control in biodosimetry. The comparison between the individual work conditions with the frequencies of unstable aberrations and micronuclei obtained from cytogenetic analysis, resulted in the change of behavior of the professionals involved in this research, with a better observance of the radioprotection standards. (author)

Analysis of 62 hybrid assembled human Y chromosomes exposes rapid structural changes and high rates of gene conversion

DEFF Research Database (Denmark)

Gonzalez-Izarzugaza, Jose Maria; Skov, Laurits; Maretty, Lasse

2017-01-01

The human Y-chromosome does not recombine across its male-specific part and is therefore an excellent marker of human migrations. It also plays an important role in male fertility. However, its evolution is difficult to fully understand because of repetitive sequences, inverted repeats and the po......The human Y-chromosome does not recombine across its male-specific part and is therefore an excellent marker of human migrations. It also plays an important role in male fertility. However, its evolution is difficult to fully understand because of repetitive sequences, inverted repeats...... and the potentially large role of gene conversion. Here we perform an evolutionary analysis of 62 Y-chromosomes of Danish descent sequenced using a wide range of library insert sizes and high coverage, thus allowing large regions of these chromosomes to be well assembled. These include 17 father-son pairs, which we...... use to validate variation calling. Using a recent method that can integrate variants based on both mapping and de novo assembly, we genotype 10898 SNVs and 2903 indels (max length of 27241 bp) in our sample and show by father-son concordance and experimental validation that the non-recurrent SNP...

Persistence of X-ray-induced chromosomal rearrangements in long-term cultures of human diploid fibroblasts

International Nuclear Information System (INIS)

Kano, Y.; Little, J.B.

1984-01-01

As part of a long-term study of mechanisms of human cell neoplastic transformation, the authors have examined the change in the frequencies of X-ray-induced chromosome rearrangements in density-inhibited human foreskin fibroblasts as a function of subculture time. In nonproliferating cells, the frequency of chromosomal aberrations declined within 24 to 48 hr but still remained at a relatively high level up to 43 days after irradiation. Aberrations disappeared rapidly, however, when the cells were allowed to proliferate, indicating that these lesions are lethal to dividing cells. The frequency of induced translocations, as determined by analysis of G-banded karyotypes, was dose dependent and remained stable up to 20 mean population doublings after irradiation. When subculture of density-inhibited cultures was delayed for 4 hr after irradiation (confluent holding), the frequency of chromosomal aberrations in the first mitosis declined, whereas the translocation frequencies at later passage were elevated as compared with cells subcultured immediately. This correlates with the reported increase in the frequency of transformation under similar conditions. These findings support the hypothesis that chromosomal rearrangements induced by DNA damage may be involved in the initiation of cancer

Painting of fourth and chromosome-wide regulation of the 4th chromosome in Drosophila melanogaster.

Science.gov (United States)

Johansson, Anna-Mia; Stenberg, Per; Bernhardsson, Carolina; Larsson, Jan

2007-05-02

Drosophila melanogaster exhibits two expression-regulating systems that target whole, specific chromosomes: the dosage compensation system whereby the male-specific lethal complex doubles transcription of genes on the male X-chromosome and the chromosome 4-specific protein Painting of fourth, POF. POF is the first example of an autosome-specific protein and its presence raises the question of the universality of chromosome-specific regulation. Here we show that POF and heterochromatin protein 1 (HP1) are involved in the global regulation of the 4th chromosome. Contrary to previous conclusions, Pof is not essential for survival of diplo-4th karyotype flies. However, Pof is essential for survival of haplo-4th individuals and expression of chromosome 4 genes in diplo-4th individuals is decreased in the absence of Pof. Mapping of POF using chromatin immunoprecipitation suggested that it binds within genes. Furthermore, we show that POF binding is dependent on heterochromatin and that POF and HP1 bind interdependently to the 4th chromosome. We propose a balancing mechanism involving POF and HP1 that provides a feedback system for fine-tuning expression status of genes on the 4th chromosome.

Three-dimensional visualization of a human chromosome using coherent x-ray diffraction

International Nuclear Information System (INIS)

Nishino, Yoshinori; Ishikawa, Tetsuya; Takahashi, Yukio; Imamoto, Naoko; Maeshima, Kazuhiro

2010-01-01

We succeeded in observing a human chromosome in two- and three-dimensions using x-ray diffraction microscopy. X-ray diffraction microscopy is a lens-less imaging technique utilizing coherent x-ray diffraction, and can overcome various limitations in conventional lens-based x-ray microscopy. Biological applications of the method have been limited to 2D observation, and 3D observation has been long waited. We found that the reconstructed chromosome images contain high-density axial structure, which has not been observed under unstained or unlabeled conditions. The result experimentally demonstrates the effectiveness of x-ray diffraction microscopy in observing internal structures of unstained biological samples with high image contrast. (author)

Chromosome locations of genes encoding human signal transduction adapter proteins, Nck (NCK), Shc (SHC1), and Grb2 (GRB2)

DEFF Research Database (Denmark)

Huebner, K; Kastury, K; Druck, T

1994-01-01

"adapter" proteins, which are involved in transducing signals from receptor tyrosine kinases to downstream signal recipients such as ras, because adaptor protein genes could also, logically, serve as targets of mutation, rearrangement, or other aberration in disease. Therefore, DNAs from panels of rodent-human......Abnormalities due to chromosomal aberration or point mutation in gene products of growth factor receptors or in ras gene products, which lie on the same signaling pathway, can cause disease in animals and humans. Thus, it can be important to determine chromosomal map positions of genes encoding...... hybrids carrying defined complements of human chromosomes were assayed for the presence of the cognate genes for NCK, SHC, and GRB2, three SH2 or SH2/SH3 (Src homology 2 and 3) domain-containing adapter proteins. Additionally, NCK and SHC genes were more narrowly localized by chromosomal in situ...

The effects of severe mixed environmental pollution on human chromosomes.

Science.gov (United States)

Katsantoni, A; Nakou, S; Antoniadou-Koumatou, I; Côté, G B

1986-01-01

Cytogenetic studies were conducted on healthy young mothers, shortly after child birth, in two residential areas each with an approximate population of 20,000, situated about 25 km from Athens, Greece. One of the areas, Elefsis, is subject to severe mixed industrial pollution, and the other, Koropi, is relatively free of pollution. Chromosomal aberrations were investigated in 16 women from each area in 72 hour lymphocyte cultures treated with gentian violet to enhance any chromosomal instability induced by the pollution. The women were of a comparable socioeconomic level, aged between 20 and 31 years, and with no history of factors associated with mutagenesis. Venous blood samples were taken from the two groups and processed concurrently. The slides were coded and examined independently by two observers, who were unaware of the source of the samples. A total of 100 cells was examined on each sample. The two observers obtained highly comparable results. Women from Elefsis had an average of 0.42 anomalies per cell and those from Koropi had 0.39. The absence of a statistically significant difference between the two groups clearly shows that the severe mixed environmental pollution of Elefsis has no significant visible effect on human chromosomes in most residents. However, two Elefsis women had abnormal results and could be at risk. Their presence is not sufficient to raise significantly their group's average, but the induction by pollution of an increased rate of chromosomal anomalies in only a few people at risk could account for the known association between urban residence and cancer mortality. PMID:3783622

Chromosomal mutations and chromosome loss measured in a new human-hamster hybrid cell line, ALC: studies with colcemid, ultraviolet irradiation, and 137Cs gamma-rays

Science.gov (United States)

Kraemer, S. M.; Waldren, C. A.; Chatterjee, A. (Principal Investigator)

1997-01-01

Small mutations, megabase deletions, and aneuploidy are involved in carcinogenesis and genetic defects, so it is important to be able to quantify these mutations and understand mechanisms of their creation. We have previously quantified a spectrum of mutations, including megabase deletions, in human chromosome 11, the sole human chromosome in a hamster-human hybrid cell line AL. S1- mutants have lost expression of a human cell surface antigen, S1, which is encoded by the M1C1 gene at 11p13 so that mutants can be detected via a complement-mediated cytotoxicity assay in which S1+ cells are killed and S1- cells survive. But loss of genes located on the tip of the short arm of 11 (11p15.5) is lethal to the AL hybrid, so that mutants that have lost the entire chromosome 11 die and escape detection. To circumvent this, we fused AL with Chinese hamster ovary (CHO) cells to produce a new hybrid, ALC, in which the requirement for maintaining 11p15.5 is relieved, allowing us to detect mutations events involving loss of 11p15.5. We evaluated the usefulness of this hybrid by conducting mutagenesis studies with colcemid, 137Cs gamma-radiation and UV 254 nm light. Colcemid induced 1000 more S1- mutants per unit dose in ALC than in AL; the increase for UV 254 nm light was only two-fold; and the increase for 137Cs gamma-rays was 12-fold. The increase in S1- mutant fraction in ALC cells treated with colcemid and 137Cs gamma-rays were largely due to chromosome loss and 11p deletions often containing a breakpoint within the centromeric region.

Cytogenetic evaluation of human glial tumors: correlation of overexpression of epidermal growth factor receptor (EGFB) with abnormalities of chromosome 7

International Nuclear Information System (INIS)

Bell, C.W.

1987-01-01

Chromosome banding analysis of human glial tumors were performed using G- and Q-banding techniques in an attempt to establish recurring sites of chromosome change. Results revealed a nonrandom karyotypic profile including aneuploidy and considerable variation in chromosome number (range 40 → 200). All tumors examined displayed numerical abnormalities, with the most common numeric change being a gain of chromosome 7. An attempt was then made to correlate the observed chromosome 7 changes with activation of the cellular proto-oncogene c-erb-B, whose produce is the epidermal growth factor receptor (EGFR). Six human glial tumors were analyzed for 125 I-EGF binding, EGFR gene copy number, EGFR gene rearrangement, mRNA expression, and karyotypic profile. Saturation analysis at 4 0 C revealed significant numbers of EGFR's in all 6 tumors. Southern blotting analysis utilizing cDNA probes for the EGFR failed to demonstrate significant amplification or structural rearrangement of the EFGR gene. The results suggest that overexpression of the EGFR may be related to an alternative mechanism, other than gene amplification and elevated mRNA levels, such as the regulation of receptor biosynthesis and degradation. In summary, findings indicate that alterations of chromosome 7 are the most prevalent chromosomal change in human glial tumors, and that these alterations may lead to overexpression of the protooncogene c-erb-B

Gene expression, nucleotide composition and codon usage bias of genes associated with human Y chromosome.

Science.gov (United States)

Choudhury, Monisha Nath; Uddin, Arif; Chakraborty, Supriyo

2017-06-01

Analysis of codon usage pattern is important to understand the genetic and evolutionary characteristics of genomes. We have used bioinformatic approaches to analyze the codon usage bias (CUB) of the genes located in human Y chromosome. Codon bias index (CBI) indicated that the overall extent of codon usage bias was low. The relative synonymous codon usage (RSCU) analysis suggested that approximately half of the codons out of 59 synonymous codons were most frequently used, and possessed a T or G at the third codon position. The codon usage pattern was different in different genes as revealed from correspondence analysis (COA). A significant correlation between effective number of codons (ENC) and various GC contents suggests that both mutation pressure and natural selection affect the codon usage pattern of genes located in human Y chromosome. In addition, Y-linked genes have significant difference in GC contents at the second and third codon positions, expression level, and codon usage pattern of some codons like the SPANX genes in X chromosome.

Rearrangement of a common cellular DNA domain on chromosome 4 in human primary liver tumors

International Nuclear Information System (INIS)

Pasquinelli, C.; Garreau, F.; Bougueleret, L.; Cariani, E.; Thiers, V.; Croissant, O.; Hadchouel, M.; Tiollais, P.; Brechot, C.; Grzeschik, K.H.

1988-01-01

Hepatitis B virus (HBV) DNA integration has been shown to occur frequently in human hepatocellular carcinomas. The authors have investigated whether common cellular DNA domains might be rearranged, possibly by HBV integration, in human primary liver tumors. Unique cellular DNA sequences adjacent to an HBV integration site were isolated from a patient with hepatitis B surface antigen-positive hepatocellular carcinoma. These probes detected rearrangement of this cellular region of chromosomal DNA in 3 of 50 additional primary liver tumors studied. Of these three tumor samples, two contained HBV DNA, without an apparent link between the viral DNA and the rearranged allele; HBV DNA sequences were not detected in the third tumor sample. By use of a panel of somatic cell hybrids, these unique cellular DNA sequences were shown to be located on chromosome 4. Therefore, this region of chromosomal DNA might be implicated in the formation of different tumors at one step of liver cell transformation, possible related to HBV integration

Descriptive evaluation of chromosome aberrations in blood lymphocytes due to gamma-irradiation

International Nuclear Information System (INIS)

Medina III, F.S.; Gregorio, J.S.; Vinoya, P.C.; Panlaque, C.A.

1983-01-01

To induce and evaluate the effect of radiation among Filipinos, frequencies and types of ν-ray induced chromosome aberrations were studied with peripheral lymphocytes from 19 donors. Peripheral blood samples were irradiated at 0 Gray, 500 mGy, 1 Gy, 2 Gy, 3 Gy and 4 Gy. Irradiated blood samples were cultured by the same standard technique as that commonly used for human blood lymphocytes. Our observations showed that irradiation causes chromosomal aberration similar to effects observed in Caucasians. Our study confirm that irradiation causes an increase of the chromosome aberrations types normally found in the control (gaps, chromatid breaks and chromosome fragments) and can induce aberrations which are rarely observed in non-exposed individual (deletions, translocations, polycentrics, rings, and despiralizations). (author)

Neurocognitive Outcomes of Individuals with a Sex Chromosome Trisomy: XXX, XYY, or XXY--A Systematic Review

Science.gov (United States)

Leggett, Victoria; Jacobs, Patricia; Nation, Kate; Scerif, Gaia; Bishop, Dorothy V. M.

2010-01-01

Aim: To review systematically the neurodevelopmental characteristics of individuals with sex chromosome trisomies (SCTs). Method: A bibliographic search identified English-language articles on SCTs. The focus was on studies unbiased by clinical referral, with power of at least 0.69 to detect an effect size of 1.0. Results: We identified 35…

Colocalization of coregulated genes: a steered molecular dynamics study of human chromosome 19.

Directory of Open Access Journals (Sweden)

Marco Di Stefano

Full Text Available The connection between chromatin nuclear organization and gene activity is vividly illustrated by the observation that transcriptional coregulation of certain genes appears to be directly influenced by their spatial proximity. This fact poses the more general question of whether it is at all feasible that the numerous genes that are coregulated on a given chromosome, especially those at large genomic distances, might become proximate inside the nucleus. This problem is studied here using steered molecular dynamics simulations in order to enforce the colocalization of thousands of knowledge-based gene sequences on a model for the gene-rich human chromosome 19. Remarkably, it is found that most (≈ 88% gene pairs can be brought simultaneously into contact. This is made possible by the low degree of intra-chromosome entanglement and the large number of cliques in the gene coregulatory network. A clique is a set of genes coregulated all together as a group. The constrained conformations for the model chromosome 19 are further shown to be organized in spatial macrodomains that are similar to those inferred from recent HiC measurements. The findings indicate that gene coregulation and colocalization are largely compatible and that this relationship can be exploited to draft the overall spatial organization of the chromosome in vivo. The more general validity and implications of these findings could be investigated by applying to other eukaryotic chromosomes the general and transferable computational strategy introduced here.

Suppression of topoisomerase IIα expression and function in human cells decreases chromosomal radiosensitivity

International Nuclear Information System (INIS)

Terry, Samantha Y.A.; Riches, Andrew C.; Bryant, Peter E.

2009-01-01

The mechanism behind chromatid break formation is as yet unclear, although it is known that DNA double-strand breaks (DSBs) are the initiating lesions. Chromatid breaks formed in cells in the G2-phase of the cell-cycle disappear ('rejoin') as a function of time between radiation exposure and cell fixation. However, the kinetics of disappearance of chromatid breaks does not correspond to those of DSB rejoining, leading us to seek alternative models. We have proposed that chromatid breaks could be formed indirectly from DSB and that the mechanism involves topoisomerase IIα. In support of this hypothesis we have recently shown that frequencies of radiation-induced chromatid breaks are lower in two variant human promyelocytic leukaemic cell lines with reduced topoisomerase IIα expression. Here we report that suppression of topoisomerase IIα in human hTERT-RPE1 cells, either by its abrogation using specific siRNA or by inhibition of its catalytic activity with the inhibitor ICRF-193, causes a reduction in frequency of chromatid breaks in radiation-exposed cells. The findings support our hypothesis for the involvement of topoisomerase IIα in the formation of radiation-induced chromatid breaks, and could help explain inter-individual variation in human chromosomal radiosensitivity; elevation of which has been linked with cancer susceptibility.

Use of a human chromosome 11 radiation hybrid panel to map markers at 11q13

International Nuclear Information System (INIS)

Withers, D.; Richard, C. III; Meeker, T.C.; Maurer, S.; Evans, G.; Myers, R.M.; Cox, D.R.

1990-01-01

A human/hamster hybrid cell line containing human chromosome 11 was X-irradiated and 102-independent derivative lines were recovered. These 'radiation hybrids' contain random fragments of human chromosome 11. This radiation hybrid panel was used to score the retention of markers at band 11q13. Statistical analysis of marker co-retention patterns in the radiation hybrid panel permits a preliminary ordering and mapping of the markers used. The best order for six scored markers is: proximal - CD5 - CD20 - PGA - HST - BCL1 - SEA - distal. Additional markers are currently being scored. The six 11q13 markers above are spread over approximately 10-12 mB of DNA. The mapping data has implications for the identification of the bcl-1 gene. bcl-1 is the site of chromosome breakage in translocations associated with B lymphocytic malignancy. bcl-1 markers map at least 4 Mb away from any of four genes previously hypothesized to be activated by such translocations, thereby making them unlikely candidates for activation

Protocol for chromosome-specific probe construction using PRINS, micromanipulation and DOP-PCR techniques

Directory of Open Access Journals (Sweden)

PAULO Z. PASSAMANI

2017-12-01

Full Text Available ABSTRACT Chromosome-specific probes have been widely used in molecular cytogenetics, being obtained with different methods. In this study, a reproducible protocol for construction of chromosome-specific probes is proposed which associates in situ amplification (PRINS, micromanipulation and degenerate oligonucleotide-primed PCR (DOP-PCR. Human lymphocyte cultures were used to obtain metaphases from male and female individuals. The chromosomes were amplified via PRINS, and subcentromeric fragments of the X chromosome were microdissected using microneedles coupled to a phase contrast microscope. The fragments were amplified by DOP-PCR and labeled with tetramethyl-rhodamine-5-dUTP. The probes were used in fluorescent in situ hybridization (FISH procedure to highlight these specific regions in the metaphases. The results show one fluorescent red spot in male and two in female X chromosomes and interphase nuclei.

Cloning of the cDNA for a human homologue of the Drosophila white gene and mapping to chromosome 21q22.3.

OpenAIRE

Chen, H.; Rossier, C.; Lalioti, M. D.; Lynn, A.; Chakravarti, A.; Perrin, G.; Antonarakis, S. E.

1996-01-01

In an effort to contribute to the transcript map of human chromosome 21 and the understanding of the pathophysiology of trisomy 21, we have used exon trapping to identify fragments of chromosome 21 genes. Two trapped exons, from pools of chromosome 21-specific cosmids, showed homology to the Drosophila white (w) gene. We subsequently cloned the corresponding cDNA for a human homologue of the Drosophila w gene (hW) from human retina and fetal brain cDNA libraries. The gene belongs to the ATP-b...

Human female meiosis revised: new insights into the mechanisms of chromosome segregation and aneuploidies from advanced genomics and time-lapse imaging.

Science.gov (United States)

Capalbo, Antonio; Hoffmann, Eva R; Cimadomo, Danilo; Ubaldi, Filippo Maria; Rienzi, Laura

2017-11-01

The unbalanced transmission of chromosomes in human gametes and early preimplantation embryos causes aneuploidy, which is a major cause of infertility and pregnancy failure. A baseline of 20% of human oocytes are estimated to be aneuploid and this increases exponentially from 30 to 35 years, reaching on average 80% by 42 years. As a result, reproductive senescence in human females is predominantly determined by the accelerated decline in genetic quality of oocytes from 30 years of age. Understanding mechanisms of chromosome segregation and aneuploidies in the female germline is a crucial step towards the development of new diagnostic approaches and, possibly, for the development of therapeutic targets and molecules. Here, we have reviewed emerging mechanisms that may drive human aneuploidy, in particular the maternal age effect. We conducted a systematic search in PubMed Central of the primary literature from 1990 through 2016 following the PRISMA guidelines, using MeSH terms related to human aneuploidy. For model organism research, we conducted a literature review based on references in human oocytes manuscripts and general reviews related to chromosome segregation in meiosis and mitosis. Advances in genomic and imaging technologies are allowing unprecedented insight into chromosome segregation in human oocytes. This includes the identification of a novel chromosome segregation error, termed reverse segregation, as well as sister kinetochore configurations that were not predicted based on murine models. Elucidation of mechanisms that result in errors in chromosome segregation in meiosis may lead to therapeutic developments that could improve reproductive outcomes by reducing aneuploidy. © The Author 2017. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Culture of human oocytes with granulocyte-macrophage colony-stimulating factor has no effect on embryonic chromosomal constitution

DEFF Research Database (Denmark)

Agerholm, Inge; Loft, Anne; Hald, Finn

2010-01-01

-vitro culture of human embryos in the presence of 2 ng/ml GM-CSF resulted in 34.8% (8/23) uniformly normal embryos. Culture without 2 ng/ml GM-CSF resulted in 33.3% (9/27) uniformly normal embryos. A trend towards a higher number of TQE in the test group was observed; however, due to lack of TQE in the control...... women donating 86 oocytes. The primary endpoint was to investigate the chromosomal constitution of human embryos (fluorescence in-situ hybridization analysis for chromosomes 13, 16, 18, 21, 22, X and Y) cultured with or without GM-CSF. The secondary endpoints were number of top-quality embryos (TQE......) and number of normally developed embryos evaluated morphologically on day 3. The cytogenetic analyses demonstrated non-inferiority and therefore the chromosomal constitution of human embryos cultured in vitro in the presence of 2 ng/ml GM-CSF was no worse than the control group cultured without GM-CSF. In...

Culture of human oocytes with granulocyte-macrophage colony-stimulating factor has no effect on embryonic chromosomal constitution

DEFF Research Database (Denmark)

Agerholm, Inge; Loft, Anne; Hald, Finn

2010-01-01

women donating 86 oocytes. The primary endpoint was to investigate the chromosomal constitution of human embryos (fluorescence in-situ hybridization analysis for chromosomes 13, 16, 18, 21, 22, X and Y) cultured with or without GM-CSF. The secondary endpoints were number of top-quality embryos (TQE......) and number of normally developed embryos evaluated morphologically on day 3. The cytogenetic analyses demonstrated non-inferiority and therefore the chromosomal constitution of human embryos cultured in vitro in the presence of 2 ng/ml GM-CSF was no worse than the control group cultured without GM-CSF. In......-vitro culture of human embryos in the presence of 2 ng/ml GM-CSF resulted in 34.8% (8/23) uniformly normal embryos. Culture without 2 ng/ml GM-CSF resulted in 33.3% (9/27) uniformly normal embryos. A trend towards a higher number of TQE in the test group was observed; however, due to lack of TQE in the control...

Antarctic skuas recognize individual humans.

Science.gov (United States)

Lee, Won Young; Han, Yeong-Deok; Lee, Sang-Im; Jablonski, Piotr G; Jung, Jin-Woo; Kim, Jeong-Hoon

2016-07-01

Recent findings report that wild animals can recognize individual humans. To explain how the animals distinguish humans, two hypotheses are proposed. The high cognitive abilities hypothesis implies that pre-existing high intelligence enabled animals to acquire such abilities. The pre-exposure to stimuli hypothesis suggests that frequent encounters with humans promote the acquisition of discriminatory abilities in these species. Here, we examine individual human recognition abilities in a wild Antarctic species, the brown skua (Stercorarius antarcticus), which lives away from typical human settlements and was only recently exposed to humans due to activities at Antarctic stations. We found that, as nest visits were repeated, the skua parents responded at further distances and were more likely to attack the nest intruder. Also, we demonstrated that seven out of seven breeding pairs of skuas selectively responded to a human nest intruder with aggression and ignored a neutral human who had not previously approached the nest. The results indicate that Antarctic skuas, a species that typically inhabited in human-free areas, are able to recognize individual humans who disturbed their nests. Our findings generally support the high cognitive abilities hypothesis, but this ability can be acquired during a relatively short period in the life of an individual as a result of interactions between individual birds and humans.

Neurocognitive outcomes of individuals with a sex chromosome trisomy: XXX, XYY, or XXY: a systematic review*

Science.gov (United States)

LEGGETT, VICTORIA; JACOBS, PATRICIA; NATION, KATE; SCERIF, GAIA; BISHOP, DOROTHY V M

2010-01-01

Aim To review systematically the neurodevelopmental characteristics of individuals with sex chromosome trisomies (SCTs). Method A bibliographic search identified English-language articles on SCTs. The focus was on studies unbiased by clinical referral, with power of at least 0.69 to detect an effect size of 1.0. Results We identified 35 articles on five neonatally identified samples that had adequate power for our review. An additional 11 studies were included where cases had been identified for reasons other than neurodevelopmental concerns. Individuals with an additional X chromosome had mean IQs that were within broadly normal limits but lower than the respective comparison groups, with verbal IQ most affected. Cognitive outcomes were poorest for females with XXX. Males with XYY had normal-range IQs, but all three SCT groups (XXX, XXY, and XYY) had marked difficulties in speech and language, motor skills, and educational achievement. Nevertheless, most adults with SCTs lived independently. Less evidence was available for brain structure and for attention, social, and psychiatric outcomes. Within each group there was much variation. Interpretation Individuals with SCTs are at risk of cognitive and behavioural difficulties. However, the evidence base is slender, and further research is needed to ascertain the nature, severity, and causes of these difficulties in unselected samples. PMID:20059514

Neurocognitive outcomes of individuals with a sex chromosome trisomy: XXX, XYY, or XXY: a systematic review.

Science.gov (United States)

Leggett, Victoria; Jacobs, Patricia; Nation, Kate; Scerif, Gaia; Bishop, Dorothy V M

2010-02-01

To review systematically the neurodevelopmental characteristics of individuals with sex chromosome trisomies (SCTs). A bibliographic search identified English-language articles on SCTs. The focus was on studies unbiased by clinical referral, with power of at least 0.69 to detect an effect size of 1.0. We identified 35 articles on five neonatally identified samples that had adequate power for our review. An additional 11 studies were included where cases had been identified for reasons other than neurodevelopmental concerns. Individuals with an additional X chromosome had mean IQs that were within broadly normal limits but lower than the respective comparison groups, with verbal IQ most affected. Cognitive outcomes were poorest for females with XXX. Males with XYY had normal-range IQs, but all three SCT groups (XXX, XXY, and XYY) had marked difficulties in speech and language, motor skills, and educational achievement. Nevertheless, most adults with SCTs lived independently. Less evidence was available for brain structure and for attention, social, and psychiatric outcomes. Within each group there was much variation. Individuals with SCTs are at risk of cognitive and behavioural difficulties. However, the evidence base is slender, and further research is needed to ascertain the nature, severity, and causes of these difficulties in unselected samples.

Telomere dysfunction and chromosome instability

Energy Technology Data Exchange (ETDEWEB)

Murnane, John P., E-mail: jmurnane@radonc.ucsf.edu [Department of Radiation Oncology, University of California San Francisco, 2340 Sutter Street, San Francisco, CA 94143-1331 (United States)

2012-02-01

The ends of chromosomes are composed of a short repeat sequence and associated proteins that together form a cap, called a telomere, that keeps the ends from appearing as double-strand breaks (DSBs) and prevents chromosome fusion. The loss of telomeric repeat sequences or deficiencies in telomeric proteins can result in chromosome fusion and lead to chromosome instability. The similarity between chromosome rearrangements resulting from telomere loss and those found in cancer cells implicates telomere loss as an important mechanism for the chromosome instability contributing to human cancer. Telomere loss in cancer cells can occur through gradual shortening due to insufficient telomerase, the protein that maintains telomeres. However, cancer cells often have a high rate of spontaneous telomere loss despite the expression of telomerase, which has been proposed to result from a combination of oncogene-mediated replication stress and a deficiency in DSB repair in telomeric regions. Chromosome fusion in mammalian cells primarily involves nonhomologous end joining (NHEJ), which is the major form of DSB repair. Chromosome fusion initiates chromosome instability involving breakage-fusion-bridge (B/F/B) cycles, in which dicentric chromosomes form bridges and break as the cell attempts to divide, repeating the process in subsequent cell cycles. Fusion between sister chromatids results in large inverted repeats on the end of the chromosome, which amplify further following additional B/F/B cycles. B/F/B cycles continue until the chromosome acquires a new telomere, most often by translocation of the end of another chromosome. The instability is not confined to a chromosome that loses its telomere, because the instability is transferred to the chromosome donating a translocation. Moreover, the amplified regions are unstable and form extrachromosomal DNA that can reintegrate at new locations. Knowledge concerning the factors promoting telomere loss and its consequences is

Allelic imbalance on chromosome 1 in human breast cancer. I. Minisatellite and RFLP analysis.

Science.gov (United States)

Loupart, M L; Armour, J; Walker, R; Adams, S; Brammar, W; Varley, J

1995-01-01

In order to characterise the role of chromosome 1 more fully in breast cancer, polymorphic markers mapping along the length of the whole chromosome were used to assess a panel of 71 tumour-lymphocyte pairs for allelic imbalance. Complex patterns of alterations were established that are consistent with cytogenetic data in the literature. Deletion mapping of individuals with loss of heterozygosity identified five independent smallest common regions of deletion, two of which are novel. There are also three discrete regions showing a gain in copy number of one homologue. The two arms of the chromosome may be subject to different events; the short arm primarily undergoes interstitial deletions, whereas the long arm is subject to whole arm events (as both gains and losses) as well as regional deletions.

Paternal isodisomy of chromosome 6 in association with a maternal supernumerary marker chromosome (6)

Energy Technology Data Exchange (ETDEWEB)

James, R.S.; Crolla, J.A.; Sitch, F.L. [Salisbury District Hospital, Wiltshire (United Kingdom)] [and others

1994-09-01

Uniparental disomy may arise by a number of different mechanisms of aneuploidy correction. A population that has been identified as being at increased risk of aneuploidy are those individuals bearing supernumerary marker chromosomes (SMCs). There have been a number of cases reported of trisomy 21 in association with bi-satellited marker chromosomes have described two individuals with small inv dup (15) markers. One had paternal isodisomy of chromosome 15 and Angelman syndrome. The other had maternal heterodisomy (15) and Prader-Willi syndrome. At the Wessex Regional Genetics Laboratory we have conducted a search for uniparental disomy of the normal homologues of the chromosomes from which SMCs originated. Our study population consists of 39 probands with SMCs originating from a number of different autosomes, including 17 with SMCs of chromosome 15 origin. Using PCR amplification of microsatellite repeat sequences located distal to the regions included in the SMCs we have determined the parental origin of the two normal homologues in each case. We have identified paternal isodisomy of chromosome 6 in a female child with a supernumerary marker ring chromosome 6 in approximately 70% of peripheral blood lymphocytes. The marker was found to be of maternal origin. This is the second case of paternal isodisomy of chromosome 6 to be reported, and the first in association with a SMC resulting in a partial trisomy for a portion of the short arm of chromosome 6. In spite of this, the patient appears to be functioning appropriately for her age.

Radiation-induced chromosome aberrations and cell killing in normal human fibroblasts and ataxia telangiectasia fibroblasts

International Nuclear Information System (INIS)

Kawata, T.; Saito, M.; Uno, T.; Ito, H.; Shigematsu, N.

2003-01-01

Full text: When cells are held in a non-dividing state (G0) after irradiation, an enhanced survival can be observed compared to that of immediate plating. A change of survival depending on post irradiation condition is known to be repair of potentially lethal damage (RPLD). The effects of confluent holding recovery (24-h incubation following irradiation) on chromosome aberrations in normal human fibroblasts (AG1522) and ataxia telangiectasia fibroblasts (GM02052C) were examined. A chemical-induced premature chromosome condensation (PCC) technique with fluorescent in situ hybridization (FISH) was applied to study chromosome aberrations in G2 and M-phase. Results from cell survival showed that the capacity for potentially lethal damage repair was normal in AG1522 cells but very little in GM02052C cells. The frequency of chromosome aberrations in AG1522 cells decreased when cells were allowed to repair for 24-h. Especially complex type exchanges were found to decrease markedly at high doses (4Gy and 6Gy). However, the frequency of chromosome aberrations including complex type exchanges showed little decrease in GM02052C cells. Confluent holding can effectively reduce chromosome aberrations, especially complex type exchanges in normal cells

Sequence and expression analysis of gaps in human chromosome 20

DEFF Research Database (Denmark)

Minocherhomji, Sheroy; Seemann, Stefan; Mang, Yuan

2012-01-01

/or overlap disease-associated loci, including the DLGAP4 locus. In this study, we sequenced ~99% of all three unfinished gaps on human chr 20, determined their complete genomic sizes and assessed epigenetic profiles using a combination of Sanger sequencing, mate pair paired-end high-throughput sequencing......The finished human genome-assemblies comprise several hundred un-sequenced euchromatic gaps, which may be rich in long polypurine/polypyrimidine stretches. Human chromosome 20 (chr 20) currently has three unfinished gaps remaining on its q-arm. All three gaps are within gene-dense regions and...... and chromatin, methylation and expression analyses. We found histone 3 trimethylated at Lysine 27 to be distributed across all three gaps in immortalized B-lymphocytes. In one gap, five novel CpG islands were predominantly hypermethylated in genomic DNA from peripheral blood lymphocytes and human cerebellum...

Generation of meiomaps of genome-wide recombination and chromosome segregation in human oocytes

DEFF Research Database (Denmark)

Ottolini, Christian S; Capalbo, Antonio; Newnham, Louise

2016-01-01

We have developed a protocol for the generation of genome-wide maps (meiomaps) of recombination and chromosome segregation for the three products of human female meiosis: the first and second polar bodies (PB1 and PB2) and the corresponding oocyte. PB1 is biopsied and the oocyte is artificially......-nucleotide polymorphisms (SNPs) genome-wide by microarray. Informative maternal heterozygous SNPs are phased using a haploid PB2 or oocyte as a reference. A simple algorithm is then used to identify the maternal haplotypes for each chromosome, in all of the products of meiosis for each oocyte. This allows mapping...

Risk of cancer in an occupationally exposed cohort with increased level of chromosomal aberrations.

Science.gov (United States)

Smerhovsky, Z; Landa, K; Rössner, P; Brabec, M; Zudova, Z; Hola, N; Pokorna, Z; Mareckova, J; Hurychova, D

2001-01-01

We used cytogenetic analysis to carry out a cohort study in which the major objective was to test the association between frequency of chromosomal aberrations and subsequent risk of cancer. In spite of the extensive use of the cytogenetic analysis of human peripheral blood lymphocytes in biomonitoring of exposure to various mutagens and carcinogens on an ecologic level, the long-term effects of an increased frequency of chromosomal aberrations in individuals are still uncertain. Few epidemiologic studies have addressed this issue, and a moderate risk of cancer in individuals with an elevated frequency of chromosomal aberrations has been observed. In the present study, we analyzed data on 8,962 cytogenetic tests and 3,973 subjects. We found a significant and strong association between the frequency of chromosomal aberrations and cancer incidence in a group of miners exposed to radon, where a 1% increase in frequency of chromosomal aberrations was followed by a 64% increase in risk of cancer (p < 0.000). In contrast, the collected data are inadequate for a critical evaluation of the association with exposure to other chemicals. PMID:11171523

Genomic instability after targeted irradiation of human lymphocytes: Evidence for inter-individual differences under bystander conditions

International Nuclear Information System (INIS)

Kadhim, Munira A.; Lee, Ryonfa; Moore, Stephen R.; Macdonald, Denise A.; Chapman, Kim L.; Patel, Gaurang; Prise, Kevin M.

2010-01-01

Environmental 222 radon exposure is a human health concern, and many studies demonstrate that very low doses of high LET α-particle irradiation initiate deleterious genetic consequences in both irradiated and non-irradiated bystander cells. One consequence, radiation-induced genomic instability (RIGI), is a hallmark of tumorigenesis and is often assessed by measuring delayed chromosomal aberrations. We utilised a technique that facilitates transient immobilization of primary lymphocytes for targeted microbeam irradiation and have reported that environmentally relevant doses, e.g. a single 3 He 2+ particle traversal to a single cell, are sufficient to induce RIGI. Herein we sought to determine differences in radiation response in lymphocytes isolated from five healthy male donors. Primary lymphocytes were irradiated with a single particle per cell nucleus. We found evidence for inter-individual variation in radiation response (RIGI, measured as delayed chromosome aberrations). Although this was not highly significant, it was possibly masked by high levels of intra-individual variation. While there are many studies showing a link between genetic predisposition and RIGI, there are few studies linking genetic background with bystander effects in normal human lymphocytes. In an attempt to investigate inter-individual variation in the induction of bystander effects, primary lymphocytes were irradiated with a single particle under conditions where fractions of the population were traversed. We showed a marked genotype-dependent bystander response in one donor after exposure to 15% of the population. The findings may also be regarded as a radiation-induced genotype-dependent bystander effect triggering an instability phenotype.

Genomic instability after targeted irradiation of human lymphocytes: Evidence for inter-individual differences under bystander conditions

Energy Technology Data Exchange (ETDEWEB)

Kadhim, Munira A., E-mail: mkadhim@brookes.ac.uk [School of Life Sciences, Oxford Brookes University, Oxford OX3 0BP (United Kingdom); Lee, Ryonfa [Biophysics, GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Planckstrasse 1, D-64291 Darmstadt (Germany); Moore, Stephen R.; Macdonald, Denise A. [Radiation and Genome Stability Unit, Medical Research Council, Harwell, Oxfordshire OX11 0RD (United Kingdom); Chapman, Kim L. [School of Life Sciences, Oxford Brookes University, Oxford OX3 0BP (United Kingdom); Patel, Gaurang; Prise, Kevin M. [Centre for Cancer Research and Cell Biology, Queen' s University Belfast, Belfast BT9 7BL (United Kingdom)

2010-06-01

Environmental {sup 222}radon exposure is a human health concern, and many studies demonstrate that very low doses of high LET {alpha}-particle irradiation initiate deleterious genetic consequences in both irradiated and non-irradiated bystander cells. One consequence, radiation-induced genomic instability (RIGI), is a hallmark of tumorigenesis and is often assessed by measuring delayed chromosomal aberrations. We utilised a technique that facilitates transient immobilization of primary lymphocytes for targeted microbeam irradiation and have reported that environmentally relevant doses, e.g. a single {sup 3}He{sup 2+} particle traversal to a single cell, are sufficient to induce RIGI. Herein we sought to determine differences in radiation response in lymphocytes isolated from five healthy male donors. Primary lymphocytes were irradiated with a single particle per cell nucleus. We found evidence for inter-individual variation in radiation response (RIGI, measured as delayed chromosome aberrations). Although this was not highly significant, it was possibly masked by high levels of intra-individual variation. While there are many studies showing a link between genetic predisposition and RIGI, there are few studies linking genetic background with bystander effects in normal human lymphocytes. In an attempt to investigate inter-individual variation in the induction of bystander effects, primary lymphocytes were irradiated with a single particle under conditions where fractions of the population were traversed. We showed a marked genotype-dependent bystander response in one donor after exposure to 15% of the population. The findings may also be regarded as a radiation-induced genotype-dependent bystander effect triggering an instability phenotype.

Linking Y-chromosomal short tandem repeat loci to human male impulsive aggression.

Science.gov (United States)

Yang, Chun; Ba, Huajie; Cao, Yin; Dong, Guoying; Zhang, Shuyou; Gao, Zhiqin; Zhao, Hanqing; Zhou, Xianju

2017-11-01

Men are more susceptible to impulsive behavior than women. Epidemiological studies revealed that the impulsive aggressive behavior is affected by genetic factors, and the male-specific Y chromosome plays an important role in this behavior. In this study, we investigated the association between the impulsive aggressive behavior and Y-chromosomal short tandem repeats (Y-STRs) loci. The collected biologic samples from 271 offenders with impulsive aggressive behavior and 492 healthy individuals without impulsive aggressive behavior were amplified by PowerPlex R Y23 PCR System and the resultant products were separated by electrophoresis and further genotyped. Then, comparisons in allele and haplotype frequencies of the selected 22 Y-STRs were made in the two groups. Our results showed that there were significant differences in allele frequencies at DYS448 and DYS456 between offenders and controls ( p  impulsive aggression. However, the DYS448-DYS456-22-15 is less related to impulsive aggression. Our results suggest a link between Y-chromosomal allele types and male impulsive aggression.

Tissue-specific expression of the human laminin alpha5-chain, and mapping of the gene to human chromosome 20q13.2-13.3 and to distal mouse chromosome 2 near the locus for the ragged (Ra) mutation

DEFF Research Database (Denmark)

Durkin, M E; Loechel, F; Mattei, M G

1997-01-01

, heart, lung, skeletal muscle, kidney, and pancreas. The human laminin alpha5-chain gene (LAMA5) was assigned to chromosome 20q13.2-q13.3 by in situ hybridization, and the mouse gene (Lama5) was mapped by linkage analysis to a syntonic region of distal chromosome 2, close to the locus for the ragged (Ra...

Correlation of chromosome patterns in human leukemic cells with exposure to chemicals and/or radiation. Progress report, January 1-July 31, 1986

International Nuclear Information System (INIS)

Rowley, J.D.

1986-08-01

Two genes for colony stimulating factors (CSF) has been mapped on chromosome five of humans. These CSFs are a family of glycoproteins that are required for the growth and maturation of myeloid progenetor cells in vitro. They are classified according to their cell specificity; thus, M-CSF (CSF-1) and G-CSF primarily stimulate cells committed to the macrophage and granulocyte lineages, respectively. Recently, the genes for both of these factors have been cloned and probes for the clonal genes were used to map their location on normal human chromosomes. Localization of CSF-1 was performed by in situ hybridization of the probe pST-CSF-17 to normal human metaphase chromosomes. This resulted in specific labeling only of chromosome 5. 8 refs., 4 figs., 2 tabs

Characterization of cDNAs encoding human leukosialin and localization of the leukosialin gene to chromosome 16

International Nuclear Information System (INIS)

Pallant, A.; Eskenazi, A.; Frelinger, J.G.; Mattei, M.G.; Fournier, R.E.K.; Carlsson, S.R.; Fukuda, M.

1989-01-01

The authors describe the isolation and characterization of cDNA clones encoding human leukosialin, a major sialoglycoprotein of human leukocytes. Leukosialin is very closely related or identical to the sialophorin molecule, which is involved in T-cell proliferation and whose expression is altered in Wiskott-Aldrich syndrome (WAS), an X-chromosome-linked immunodeficiency disease. Using a rabbit antiserum to leukosialin, a cDNA clone was isolated from a λgt11 cDNA library constructed from human peripheral blood cells. The λgt11 clone was used to isolate longer cDNA clones that correspond to the entire coding sequence of leukosialin. DNA sequence analysis reveals three domains in the predicted mature protein. The extracellular domain is enriched for Ser, Thr, and Pro and contains four contiguous 18-amino acid repeats. The transmembrane and intracellular domains of the human leukosialin molecule are highly homologous to the rat W3/13 molecule. RNA gel blot analysis reveals two polyadenylylated species of 2.3 and 8 kilobases. Southern blot analysis suggests that human leukosialin is a single-copy gene. Analysis of monochromosomal cell hybrids indicates that the leukosialin gene is not X chromosome linked and in situ hybridization shows leukosialin is located on chromosome 16. These findings demonstrate that the primary mutation in WAS is not a defect in the structural gene for leukosialin

Stabilization of chromosomes by DNA intercalators for flow karyotyping and identification by banding of isolated chromosomes

NARCIS (Netherlands)

Aten, J. A.; Buys, C. H.; van der Veen, A. Y.; Mesa, J. R.; Yu, L. C.; Gray, J. W.; Osinga, J.; Stap, J.

1987-01-01

A number of structurally unrelated DNA intercalators have been studied as stabilizers of mitotic chromosomes during isolation from rodent and human metaphase cells. Seven out of the nine intercalators tested were found to be useful as chromosome stabilizing agents. Chromosome suspensions prepared in

A Quest for Missing Proteins : update 2015 on Chromosome-Centric Human Proteome Project

NARCIS (Netherlands)

Horvatovich, Péter; Lundberg, Emma K; Chen, Yu-Ju; Sung, Ting-Yi; He, Fuchu; Nice, Edouard C; Goode, Robert J A; Yu, Simon; Ranganathan, Shoba; Baker, Mark S; Domont, Gilberto B; Velasquez, Erika; Li, Dong; Liu, Siqi; Wang, Quanhui; He, Qing-Yu; Menon, Rajasree; Guan, Yuanfang; Corrales, Fernando Jose; Segura, Victor; Casal, José Ignacio; Pascual-Montano, Alberto; Albar, Juan Pablo; Fuentes, Manuel; Gonzalez-Gonzalez, Maria; Diez, Paula; Ibarrola, Nieves; Degano, Rosa M; Mohammed, Yassene; Borchers, Christoph H; Urbani, Andrea; Soggiu, Alessio; Yamamoto, Tadashi; Archakov, Alexander I; Ponomarenko, Elena; Lisitsa, Andrey V; Lichti, Cheryl F; Mostovenko, Ekaterina; Kroes, Roger A; Rezeli, Melinda; Vegvari, Akos; Fehniger, Thomas E; Bischoff, Rainer; Vizcaíno, Juan Antonio; Deutsch, Eric W; Lane, Lydie; Nilsson, Carol L; Marko-Varga, György; Omenn, Gilbert S; Jeong, Seul-Ki; Cho, Jin-Young; Paik, Young-Ki; Hancock, William S

2015-01-01

This paper summarizes the recent activities of the Chromosome-Centric Human Proteome Project (C-HPP) consortium, which develops new technologies to identify yet-to-be annotated proteins (termed "missing proteins") in biological samples that lack sufficient experimental evidence at the protein level

Low level dose induced chromosome aberrations in human blood lymphocytes

International Nuclear Information System (INIS)

Pohl-Rueling, J.

1992-01-01

Unstable structural aberrations in chromosomes of human blood lymphocytes cannot be used as biological dosemeters in the low dose range, when extrapolating from high doses using a linear dose response, as required by the original formula of the dual radiation action theory. A survey is given of experimental dose-response curves of chromosome aberrations, obtained in investigations not only by this institute, in cooperation with many other laboratories, but also by various authors in different areas of the world. The results are not compatible with the predicted linear dose relationships at in vivo dose ranges up to 30 mGy.y -1 . The aberration frequencies rise sharply with dose within the normal environmental exposure up to about twice that level. At higher doses, aberration frequencies increase less rapidly and reach a plateau. Some in vitro experiments of various authors with higher doses of low LET radiations, up to about 400 mGy have found dose responses with steps. (author)

Comparative Genomic Hybridization of Human Malignant Gliomas Reveals Multiple Amplification Sites and Nonrandom Chromosomal Gains and Losses

Science.gov (United States)

Schròck, Evelin; Thiel, Gundula; Lozanova, Tanka; du Manoir, Stanislas; Meffert, Marie-Christine; Jauch, Anna; Speicher, Michael R.; Nürnberg, Peter; Vogel, Siegfried; Janisch, Werner; Donis-Keller, Helen; Ried, Thomas; Witkowski, Regine; Cremer, Thomas

1994-01-01

Nine human malignant gliomas (2 astrocytomas grade III and 7 glioblastomas) were analyzed using comparative genomic hybridization (CGH). In addition to the amplification of the EGFR gene at 7p12 in 4 of 9 cases, six new amplification sites were mapped to 1q32, 4q12, 7q21.1, 7q21.2-3, 12p, and 22q12. Nonrandom chromosomal gains and losses were identified with overrepresentation of chromosome 7 and underrepresentation of chromosome 10 as the most frequent events (1 of 2 astrocytomas, 7 of 7 glioblastomas). Gain of a part or the whole chromosome 19 and losses of chromosome bands 9pter-23 and 22q13 were detected each in five cases. Loss of chromosome band 17p13 and gain of chromosome 20 were revealed each in three cases. The validity of the CGH data was confirmed using interphase cytogenetics with YAC clones, chromosome painting in tumor metaphase spreads, and DNA fingerprinting. A comparison of CGH data with the results of chromosome banding analyses indicates that metaphase spreads accessible in primary tumor cell cultures may not represent the clones predominant in the tumor tissue ImagesFigure 1Figure 4Figure 6 PMID:8203461

[Familial febrile convulsions is supposed to link to human chromosome 19p13.3].

Science.gov (United States)

Qi, Y; Lü, J; Wu, X

2001-01-10

To localize the familial febrile convulsion (FC) genes on human chromosomes. For 63 FC pedigrees, tetranucleotide repeat markers D19S253 D19S395 and D19S591 on the short arm of chromosome 19, as well as dinucleotide repeat markers D8S84 and D8S85 on the long arm of chromosome 8 were genotyped. Transmission disequilibrium test (TDT) and Lod score calculation were carried out. The data were processed by PPAP software package. All the alleles in every locus of FC probands and normal controls were in Hardy-Weinburg balance. Transmission disequilibrium was found on D8S84, D19S395 and D19S591 in FC families. chi(2) values were 4.0, 5.124 and 7.364 separately. Each P value was < 0.05, and significantly meaningful. The two-point Lod scores between D8S84 and FC, D8S85 and FC, D19S253 and FC, D19S395 and FC, D19S591 and FC are 0.00002, 0.000017, 0.58, 1.53 and 1.42 respectively. The multi-point Lod score among markers on chromosome 8q and FC was 0.88, while Lod score among markers on chromosome 19p and FC reached 2.78. The results by both the non-parameter (TDT) and parameter (Lod score) methods were consistant on a whole. FC is linked with chromosome region 19p13.3, but not with chromosome 8q.

Cell cycle phase of nondividing cells in aging human cell cultures determined by DNA content and chromosomal constitution

International Nuclear Information System (INIS)

Yanishevsky, R.M.

1975-01-01

Human diploid cell cultures, strain WI-38, have a finite proliferative capacity and have been proposed as a model of biological aging. To identify the cell cycle phase of the nondividing cells, cultures of various ages were exposed to 3 Hdt for 48 hours to label dividing cells, then the cycle phase was identified for individual cells by one of two methods, and finally, the proliferative status of the same cells was scored by autoradiographic evidence of 3 HdT uptake. The methods to identify the cycle phase were: determination of DNA strain content by Feulgen scanning cytophotometry, and determination of chromosome constitution by the technique of premature chromosome condensation (PCC). Preliminary experiments showed the effect of continuous exposure to various levels of 3 HdT on cell growth. High levels of 3 HdT inhibited cell cycle traverse: the cell number and labeling index curves reached a plateau; the cell volume increased; the cells accumulated with 4C DNA contents and it appeared that they blocked in G 2 phase. This pattern is consistent with a radiation effect. (U.S.)

Comparative mapping of DNA probes derived from the V{sub k} immunoglobulin gene regions on human and great ape chromosomes by fluorescence in situ hybridization

Energy Technology Data Exchange (ETDEWEB)

Arnold, N.; Wienberg, J.; Ermert, K. [Universitaet Muenchen (Germany)] [and others

1995-03-01

Fluorescence in situ hybridization (FISH) of cosmid clones of human V{sub K} gene regions to human and primate chromosomes contributed to the dating of chromosome reorganizations in evolution. A clone from the K locus at 2p11-p12 (cos 106) hybridized to the assumed homologous chromosome bands in the chimpanzees Pan troglodytes (PTR) and P. paniscus (PPA), the Gorilla gorilla (GGO), and the orangutan Pongo Pygmaeus (PPY). Human and both chimpanzees differed from gorilla and orangutan by the mapping of cos 170, a clone derived from chromosome 2cen-q11.2; the transposition of this orphon to the other side of the centromere can, therefore, be dated after the human/chimpanzee and gorilla divergence. Hybridization to homologous bands was also found with a cosmid clone containing a V{sub K}I orphon located on chromosome 1 (cos 115, main signal at 1q31-q32), although the probe is not fully unique. Also, a clone derived from the orphon V{sub K} region on chromosome 22q11 (cos 121) hybridized to the homologous bands in the great apes. This indicates that the orphons on human chromosomes 1 and 22 had been translocated early in primate evolution. 18 refs., 2 figs.

Biodosimetry of ionizing radiation by selective painting of prematurely condensed chromosomes in human lymphocytes

Science.gov (United States)

Durante, M.; George, K.; Yang, T. C.

1997-01-01

Painting of interphase chromosomes can be useful for biodosimetric purposes in particular cases such as radiation therapy, accidental exposure to very high radiation doses and exposure to densely ionizing radiation, for example during space missions. Biodosimetry of charged-particle radiation is analyzed in the present paper. Target cells were human peripheral blood lymphocytes irradiated in vitro with gamma rays, protons and iron ions. After exposure, lymphocytes were incubated for different times to allow repair of radiation-induced damage and then fused to mitotic hamster cells to promote premature condensation in the interphase chromosomes. Chromosome spreads were then hybridized with whole-chromosome DNA probes labeled with fluorescent stains. Dose-response curves for the induction of chromatin fragments shortly after exposure, as well as the kinetics of rejoining and misrejoining, were not markedly dependent on linear energy transfer. However, after exposure to heavy ions, more aberrations were scored in the interphase cells after incubation for repair than in metaphase samples harvested at the first postirradiation mitosis. On the other hand, no significant differences were observed in the two samples after exposure to sparsely ionizing radiation. These results suggest that interphase chromosome painting can be a useful tool for biodosimetry of particle radiation.

Human sperm sex chromosome disomy and sperm DNA damage assessed by the neutral comet assay.

Science.gov (United States)

McAuliffe, M E; Williams, P L; Korrick, S A; Dadd, R; Marchetti, F; Martenies, S E; Perry, M J

2014-10-10

Is there an association between human sperm sex chromosome disomy and sperm DNA damage? An increase in human sperm XY disomy was associated with higher comet extent; however, there was no other consistent association of sex chromosome disomies with DNA damage. There is limited published research on the association between sex chromosome disomy and sperm DNA damage and the findings are not consistent across studies. We conducted a cross-sectional study of 190 men (25% ever smoker, 75% never smoker) from subfertile couples presenting at the Massachusetts General Hospital Fertility Clinic from January 2000 to May 2003. Multiprobe fluorescence in situ hybridization for chromosomes X, Y and 18 was used to determine XX, YY, XY and total sex chromosome disomy in sperm nuclei using an automated scoring method. The neutral comet assay was used to measure sperm DNA damage, as reflected by comet extent, percentage DNA in the comet tail, and tail distributed moment. Univariate and multiple linear regression models were constructed with sex chromosome disomy (separate models for each of the four disomic conditions) as the independent variable, and DNA damage parameters (separate models for each measure of DNA damage) as the dependent variable. Men with current or past smoking history had significantly greater comet extent (µm: regression coefficients with 95% CI) [XX18: 15.17 (1.98, 28.36); YY18: 14.68 (1.50, 27.86); XY18: 15.41 (2.37, 28.45); Total Sex Chromosome Disomy: 15.23 (2.09, 28.38)], and tail distributed moment [XX18: 3.01 (0.30, 5.72); YY18: 2.95 (0.24, 5.67); XY18: 3.04 (0.36, 5.72); Total Sex Chromosome Disomy: 3.10 (0.31, 5.71)] than men who had never smoked. In regression models adjusted for age and smoking, there was a positive association between XY disomy and comet extent. For an increase in XY disomy from 0.56 to 1.47% (representing the 25th to 75th percentile), there was a mean increase of 5.08 µm in comet extent. No other statistically significant

Generation of an approximately 2.4 Mb human X centromere-based minichromosome by targeted telomere-associated chromosome fragmentation in DT40.

Science.gov (United States)

Mills, W; Critcher, R; Lee, C; Farr, C J

1999-05-01

A linear mammalian artificial chromosome (MAC) will require at least three types of functional element: a centromere, two telomeres and origins of replication. As yet, our understanding of these elements, as well as many other aspects of structure and organization which may be critical for a fully functional mammalian chromosome, remains poor. As a way of defining these various requirements, minichromosome reagents are being developed and analysed. Approaches for minichromosome generation fall into two broad categories: de novo assembly from candidate DNA sequences, or the fragmentation of an existing chromosome to reduce it to a minimal size. Here we describe the generation of a human minichromosome using the latter, top-down, approach. A human X chromosome, present in a DT40-human microcell hybrid, has been manipulated using homologous recombination and the targeted seeding of a de novo telomere. This strategy has generated a linear approximately 2.4 Mb human X centromere-based minichromosome capped by two artificially seeded telomeres: one immediately flanking the centromeric alpha-satellite DNA and the other targeted to the zinc finger gene ZXDA in Xp11.21. The chromosome retains an alpha-satellite domain of approximately 1. 8 Mb, a small array of gamma-satellite repeat ( approximately 40 kb) and approximately 400 kb of Xp proximal DNA sequence. The mitotic stability of this minichromosome has been examined, both in DT40 and following transfer into hamster and human cell lines. In all three backgrounds, the minichromosome is retained efficiently, but in the human and hamster microcell hybrids its copy number is poorly regulated. This approach of engineering well-defined chromosome reagents will allow key questions in MAC development (such as whether a lower size limit exists) to be addressed. In addition, the 2.4 Mb minichromosome described here has potential to be developed as a vector for gene delivery.

Gold nanoparticle-assisted primer walking for closing the human chromosomal gap

DEFF Research Database (Denmark)

Li, H; Shi, B; Li, X

2013-01-01

The finished sequence of the human genome still contains 260 euchromatic gaps. All the PCR-based genome walking techniques used to close gaps have common limitations, such as low efficiency and low specificity. We herein describe a strategy to solve this problem by employing gold nanoparticles (Au......NPs) to improve the efficiency in primer walking amplification. We used this strategy to close a gap in human chromosome 5 containing a DNA stretch composed of the 12SAT repeat. The obtained gap sequence is highly conserved among several mammalian genomes. The demonstrated AuNP-assisted primer walking strategy...

Chromosomal evolution and phylogenetic analyses in Tayassu ...

Indian Academy of Sciences (India)

Chromosome preparation and karyotype description. The material analysed consists of chromosome preparations of the tayassuid species T. pecari (three individuals) and. P. tajacu (four individuals) and were made from short-term lymphocyte cultures of whole blood samples using standard protocols (Chaves et al. 2002).

[Architecture of the X chromosome, expression of LIM kinase 1, and recombination in the agnostic mutants of Drosophila: a model of human Williams syndrome].

Science.gov (United States)

Savvateeva-Popova, E V; Peresleni, A I; Sharagina, L M; Medvedeva, A V; Korochkina, S E; Grigor'eva, I V; Diuzhikova, N A; Popov, A V; Baricheva, E M; Karagodin, D; Heisenberg, M

2004-06-01

As the Human Genome and Drosophila Genome Projects were completed, it became clear that functions of human disease-associated genes may be elucidated by studying the phenotypic expression of mutations affecting their structural or functional homologs in Drosophila. Genomic diseases were identified as a new class of human disorders. Their cause is recombination, which takes place at gene-flanking duplicons to generate chromosome aberrations such as deletions, duplications, inversions, and translocations. The resulting imbalance of the dosage of developmentally important genes arises at a frequency of 10(-3) (higher than the mutation rate of individual genes) and leads to syndromes with multiple manifestations, including cognitive defects. Genomic DNA fragments were cloned from the Drosophila melanogaster agnostic locus, whose mutations impair learning ability and memory. As a result, the locus was exactly localized in X-chromosome region 11A containing the LIM kinase 1 (LIMK1) gene (CG1848), which is conserved among many species. Hemizygosity for the LIMK1 gene, which is caused by recombination at neighboring extended repeats, underlies cognitive disorders in human Williams syndrome. LIMK1 is a component of the integrin signaling cascade, which regulates the functions of the actin cytoskeleton, synaptogenesis, and morphogenesis in the developing brain. Immunofluorescence analysis revealed LIMK1 in all subdomains of the central complex and the visual system of Drosophila melanogaster. Like in the human genome, the D. melanogaster region is flanked by numerous repeats, which were detected by molecular genetic methods and analysis of ectopic chromosome pairing. The repeats determined a higher rate of spontaneous and induced recombination. including unequal crossing over, in the agnostic gene region. Hence, the agnostic locus was considered as the first D. melanogaster model suitable for studying the genetic defect associated with Williams syndrome in human.

Effects of radiation and porphyrin on mitosis and chromosomes in human hematopoietic cell lines

International Nuclear Information System (INIS)

Tan, J.C.; Huang, C.C.; Fiel, R.J.

1976-01-01

The effect on mitosis of a human hematopoietic cell line RPMI-1788 treated with a metal chelate (Zn ++ ) of meso-tetra (p-carboxyphenyl) porphine (Zn-TCPP) alone at various concentrations or in combination with gamma-irradiation at various doses were studied. The results showed that both Zn-TCPP and radiation were effective in interfering with normal mitosis and that the effect of radiation was relatively more effective. Data also suggest interacting effects between Zn-TCPP and gamma-irradiation. At low doses of radiation, Zn-TCPP potentiated the effect of radiation. The reverse seemed to be true at a high dose of radiation. The effects of two porphyrins (Zn-TCPP and hematoporphyrin) and radiation on chromosomes were also studied. Chromosomal aberrations characteristic of radiation were observed. The porphyrins were found not to be effective chromosome-breaking agents under the experimental conditions tested

Chromosome aberrations in peripheral blood lymphocytes of individuals living in high level natural radiation areas of Ramsar, Iran: final results

International Nuclear Information System (INIS)

Zakeri, F.; Haeri, S.A.; Rajabpour, M.R.; Ahmadpour, M.J.; Kanda, R.; Hayata, I.; Nakamura, S.; Sugahara, T.

2010-01-01

The absorbed radiation dose of each individual in the HLNRA and the control area was estimated from the dose measured by an electronic pocket dosimeter (EPDTM) for one day and an optically stimulated luminescence dosimeter (OSLD) for one month. The accumulated doses per year and whole life in all individuals were estimated by both types of dosimeters. Using chromosomal aberrations as the main endpoint to assess the dose-effect relationship in residents of HLNRA, no positive correlation was found between the frequency of dicentric and centric ring aberrations and the cumulative dose of the inhabitants. These results as well as the earlier studies clearly show that individuals residing in HLNRAS of Ramsar have an increased frequency of detectable abnormalities in unstable aberrations. Due to some difficulties, the shape of the dose response has yet to be determined. In this paper, the methodologies applied and the results obtained from the most recent chromosome aberration studies in HLNRAS of Ramsar will be reviewed and discussed in order to conclude results and better understand such effects in particular in individuals of very HLNRAS of Ramsar. (author)

Origin of amphibian and avian chromosomes by fission, fusion, and retention of ancestral chromosomes

Science.gov (United States)

Voss, Stephen R.; Kump, D. Kevin; Putta, Srikrishna; Pauly, Nathan; Reynolds, Anna; Henry, Rema J.; Basa, Saritha; Walker, John A.; Smith, Jeramiah J.

2011-01-01

Amphibian genomes differ greatly in DNA content and chromosome size, morphology, and number. Investigations of this diversity are needed to identify mechanisms that have shaped the evolution of vertebrate genomes. We used comparative mapping to investigate the organization of genes in the Mexican axolotl (Ambystoma mexicanum), a species that presents relatively few chromosomes (n = 14) and a gigantic genome (>20 pg/N). We show extensive conservation of synteny between Ambystoma, chicken, and human, and a positive correlation between the length of conserved segments and genome size. Ambystoma segments are estimated to be four to 51 times longer than homologous human and chicken segments. Strikingly, genes demarking the structures of 28 chicken chromosomes are ordered among linkage groups defining the Ambystoma genome, and we show that these same chromosomal segments are also conserved in a distantly related anuran amphibian (Xenopus tropicalis). Using linkage relationships from the amphibian maps, we predict that three chicken chromosomes originated by fusion, nine to 14 originated by fission, and 12–17 evolved directly from ancestral tetrapod chromosomes. We further show that some ancestral segments were fused prior to the divergence of salamanders and anurans, while others fused independently and randomly as chromosome numbers were reduced in lineages leading to Ambystoma and Xenopus. The maintenance of gene order relationships between chromosomal segments that have greatly expanded and contracted in salamander and chicken genomes, respectively, suggests selection to maintain synteny relationships and/or extremely low rates of chromosomal rearrangement. Overall, the results demonstrate the value of data from diverse, amphibian genomes in studies of vertebrate genome evolution. PMID:21482624

Detection of chromosomal instability in α-irradiated and bystander human fibroblasts

International Nuclear Information System (INIS)

Ponnaiya, Brian; Jenkins-Baker, Gloria; Bigelow, Alan; Marino, Stephen; Geard, Charles R.

2004-01-01

There is increasing evidence biological responses to ionizing radiation are not confined to those cells that are directly hit, but may be seen in the progeny at subsequent generations (genomic instability) and in non-irradiated neighbors of irradiated cells (bystander effects). These so called non-targeted phenomena would have significant contributions to radiation-induced carcinogenesis, especially at low doses where only a limited number of cells in a population are directed hit. Here we present data using a co-culturing protocol examining chromosomal instability in α-irradiated and bystander human fibroblasts BJ1-htert. At the first cell division following exposure to 0.1 and 1 Gy α-particles, irradiated populations demonstrated a dose dependent increase in chromosome-type aberrations. At this time bystander BJ1-htert populations demonstrated elevated chromatid-type aberrations when compared to controls. Irradiated and bystander populations were also analyzed for chromosomal aberrations as a function of time post-irradiation. When considered over 25 doublings, all irradiated and bystander populations had significantly higher frequencies of chromatid aberrations when compared to controls (2-3-fold over controls) and were not dependent on dose. The results presented here support the link between the radiation-induced phenomena of genomic instability and the bystander effect

Chromosome translocations measured by fluorescence in-situ hybridization: A promising biomarker

International Nuclear Information System (INIS)

Lucas, J.N.; Straume, T.

1995-10-01

A biomarker for exposure and risk assessment would be most useful if it employs an endpoint that is highly quantitative, is stable with time, and is relevant to human risk. Recent advances in chromosome staining using fluorescence in situ hybridization (FISH) facilitate fast and reliable measurement of reciprocal translocations, a kind of DNA damage linked to both prior exposure and risk. In contrast to other biomarkers available, the frequency of reciprocal translocations in individuals exposed to whole-body radiation is stable with time post exposure, has a rather small inter-individual variability, and can be measured accurately at the low levels. Here, the authors discuss results from their studies demonstrating that chromosome painting can be used to reconstruct radiation dose for workers exposed within the dose limits, for individuals exposed a long time ago, and even for those who have been diagnosed with leukemia but not yet undergone therapy

The use of premature chromosome condensation to study in interphase cells the influence of environmental factors on human genetic material

Directory of Open Access Journals (Sweden)

Vasiliki I. Hatzi

2006-01-01

Full Text Available Nowadays, there is a constantly increasing concern regarding the mutagenic and carcinogenic potential of a variety of harmful environmental factors to which humans are exposed in their natural and anthropogenic environment. These factors exert their hazardous potential in humans' personal (diet, smoking, pharmaceuticals, cosmetics and occupational environment that constitute part of the anthropogenic environment. It is well known that genetic damage due to these factors has dramatic implications for human health. Since most of the environmental genotoxic factors induce arrest or delay in cell cycle progression, the conventional analysis of chromosomes at metaphase may underestimate their genotoxic potential. Premature Chromosome Condensation (PCC induced either by means of cell fusion or specific chemicals, enables the microscopic visualization of interphase chromosomes whose morphology depends on the cell cycle stage, as well as the analysis of structural and numerical aberrations at the G1 and G2 phases of the cell cycle. The PCC has been successfully used in problems involving cell cycle analysis, diagnosis and prognosis of human leukaemia, assessment of interphase chromosome malformations resulting from exposure to radiation or chemicals, as well as elucidation of the mechanisms underlying the conversion of DNA damage into chromosomal damage. In this report, particular emphasis is given to the advantages of the PCC methodology used as an alternative to conventional metaphase analysis in answering questions in the fields of radiobiology, biological dosimetry, toxicogenetics, clinical cytogenetics and experimental therapeutics.

On-line sorting of human chromosomes by centromeric index, and identification of sorted populations by GTG-banding and fluorescent in situ hybridization

NARCIS (Netherlands)

Boschman, G. A.; Rens, W.; Manders, E.; van Oven, C.; Barendsen, G. W.; Aten, J. A.

1990-01-01

Using slit-scan flow cytometry, the shape of human metaphase chromosomes, as expressed in their centromeric index (CI), and the DNA content of the chromosomes have been used as parameters in bivariate flow karyotyping. The resolution of the DNA vs CI flow karyogram of the larger chromosomes up to

Rise, fall and resurrection of chromosome territories: a historical perspective. Part I. The rise of chromosome territories

OpenAIRE

T Cremer; C Cremer

2009-01-01

It is now generally accepted that chromosomes in the cell nucleus are organized in distinct domains, first called chromosome territories in 1909 by the great cytologist Theodor Boveri. Yet, even today chromosomes have remained enigmatic individuals, whose structures, arrangements and functions in cycling and post-mitotic cells still need to be explored in full detail. Whereas numerous recent reviews describe present evidence for a dynamic architecture of chromosome territories and discuss the...

Individual and combined effects of ochratoxin A and citrinin on viability and DNA fragmentation in cultured Vero cells and on chromosome aberrations in mice bone marrow cells

International Nuclear Information System (INIS)

Bouslimi, Amel; Bouaziz, Chayma; Ayed-Boussema, Imen; Hassen, Wafa; Bacha, Hassen

2008-01-01

Ochratoxin A (OTA) and citrinin (CTN) are two common contaminant mycotoxins which can occur jointly in a wide range of food commodities. Both mycotoxins have several toxic effects but share a significant nephrotoxic and carcinogenic potential since OTA and CTN were reported to be responsible for naturally occurring human and animal kidney diseases and tumors. Considering the concomitant production of OTA and CTN, it is very likely that humans and animals are always exposed to the mixture rather than to individual compounds. Therefore, the aim of the present study was to investigate, in vivo and in vitro, whether DNA damage is enhanced by combination of both mycotoxins as compared to their effect separately. To this end, we have assessed their effects individually or combined on cell proliferation and DNA fragmentation in cultured Vero cells and in vivo by monitoring the induction of chromosome aberrations. Our results clearly showed that cultured renal cells respond to OTA and CTN exposure by a moderate and weak inhibition of cell proliferation, respectively. However, when combined, they exert a significant increase in inhibition of cell viability. Similar results were found for the investigated genotoxicity endpoints (DNA fragmentation and chromosome aberrations). Altogether, our study showed that OTA and CTN combination effects are clearly synergistic. The synergistic induction of DNA damage observed with OTA and CTN taken concomitantly could be relevant to explain the molecular basis of the renal diseases and tumorogenesis induced by naturally occurring mycotoxins

The Biological Effectiveness of Four Energies of Neon Ions for the Induction of Chromosome Damage in Human Lymphocytes

Science.gov (United States)

George, Kerry; Hada, Megumi; Cucinotta, F. A.

2011-01-01

Chromosomal aberrations were measured in human peripheral blood lymphocytes after in vitro exposure to neon ions at energies of 64, 89, 142, or 267. The corresponding LET values for these energies of neon ranged from 38-103 keV/micrometers and doses delivered were in the 10 to 80 cGy range. Chromosome exchanges were assessed in metaphase and G2 phase cells at first division after exposure using fluorescence in situ hybridization (FISH) with whole chromosome probes and dose response curves were generated for different types of chromosomal exchanges. The yields of total chromosome exchanges were similar for the 64, 89, and 142 MeV exposures, whereas the 267 MeV/u neon with LET of 38 keV/micrometers produced about half as many exchanges per unit dose. The induction of complex type chromosome exchanges (exchanges involving three or more breaks and two or more chromosomes) showed a clear LET dependence for all energies. The ratio of simple to complex type exchanges increased with LET from 18 to 51%. The relative biological effectiveness (RBE) was estimated from the initial slope of the dose response curve for chromosome damage with respect to gamma-rays. The RBE(sub max) values for total chromosome exchanges for the 64 MeV/u was around 30.

Effect of mobile phone station on micronucleus frequency and chromosomal aberrations in human blood cells.

Science.gov (United States)

Yildirim, M S; Yildirim, A; Zamani, A G; Okudan, N

2010-01-01

The use of mobile telephones has rapidly increased worldwide as well as the number of mobile phone base stations that lead to rise low level radiofrequency emissions which may in turn have possible harm for human health. The national radiation protection board has published the known effects of radio waves exposure on humans living close to mobile phone base stations. However, several studies have claimed that the base station has detrimental effects on different tissues. In this study, we aimed to evaluate the effects of mobile phone base stations on the micronucleus (MN) frequency and chromosomal aberrations on blood in people who were living around mobile phone base stations and healthy controls. Frequency of MN and chromosomal aberrations in study and control groups was 8.96 +/- 3.51 and 6.97 +/- 1.52 (p: 0.16); 0.36 +/- 0.31 and 0.75 +/- 0.61 (p: 0.07), respectively. Our results show that there was not a significant difference of MN frequency and chromosomal aberrations between the two study groups. The results claim that cellular phones and their base stations do not produce important carcinogenic changes.

The genomic distribution of intraspecific and interspecific sequence divergence of human segmental duplications relative to human/chimpanzee chromosomal rearrangements

Directory of Open Access Journals (Sweden)

Eichler Evan E

2008-08-01

Full Text Available Abstract Background It has been suggested that chromosomal rearrangements harbor the molecular footprint of the biological phenomena which they induce, in the form, for instance, of changes in the sequence divergence rates of linked genes. So far, all the studies of these potential associations have focused on the relationship between structural changes and the rates of evolution of single-copy DNA and have tried to exclude segmental duplications (SDs. This is paradoxical, since SDs are one of the primary forces driving the evolution of structure and function in our genomes and have been linked not only with novel genes acquiring new functions, but also with overall higher DNA sequence divergence and major chromosomal rearrangements. Results Here we take the opposite view and focus on SDs. We analyze several of the features of SDs, including the rates of intraspecific divergence between paralogous copies of human SDs and of interspecific divergence between human SDs and chimpanzee DNA. We study how divergence measures relate to chromosomal rearrangements, while considering other factors that affect evolutionary rates in single copy DNA. Conclusion We find that interspecific SD divergence behaves similarly to divergence of single-copy DNA. In contrast, old and recent paralogous copies of SDs do present different patterns of intraspecific divergence. Also, we show that some relatively recent SDs accumulate in regions that carry inversions in sister lineages.

DNA Catenation Maintains Structure of Human Metaphase Chromosomes

DEFF Research Database (Denmark)

L. V. Bauer, David; Marie, Rodolphe; Rasmussen, Kristian Hagsted

2012-01-01

Mitotic chromosome structure is pivotal to cell division but difficult to observe in fine detail using conventional methods. DNA catenation has been implicated in both sister chromatid cohesion and chromosome condensation, but has never been observed directly. We have used a lab-on-a-chip microfl...

Chromosome-specific DNA Repeat Probes

Energy Technology Data Exchange (ETDEWEB)

Baumgartner, Adolf; Weier, Jingly Fung; Weier, Heinz-Ulrich G.

2006-03-16

In research as well as in clinical applications, fluorescence in situ hybridization (FISH) has gained increasing popularity as a highly sensitive technique to study cytogenetic changes. Today, hundreds of commercially available DNA probes serve the basic needs of the biomedical research community. Widespread applications, however, are often limited by the lack of appropriately labeled, specific nucleic acid probes. We describe two approaches for an expeditious preparation of chromosome-specific DNAs and the subsequent probe labeling with reporter molecules of choice. The described techniques allow the preparation of highly specific DNA repeat probes suitable for enumeration of chromosomes in interphase cell nuclei or tissue sections. In addition, there is no need for chromosome enrichment by flow cytometry and sorting or molecular cloning. Our PCR-based method uses either bacterial artificial chromosomes or human genomic DNA as templates with {alpha}-satellite-specific primers. Here we demonstrate the production of fluorochrome-labeled DNA repeat probes specific for human chromosomes 17 and 18 in just a few days without the need for highly specialized equipment and without the limitation to only a few fluorochrome labels.

Chromosomal instability mediated by non-B DNA: cruciform conformation and not DNA sequence is responsible for recurrent translocation in humans.

Science.gov (United States)

Inagaki, Hidehito; Ohye, Tamae; Kogo, Hiroshi; Kato, Takema; Bolor, Hasbaira; Taniguchi, Mariko; Shaikh, Tamim H; Emanuel, Beverly S; Kurahashi, Hiroki

2009-02-01

Chromosomal aberrations have been thought to be random events. However, recent findings introduce a new paradigm in which certain DNA segments have the potential to adopt unusual conformations that lead to genomic instability and nonrandom chromosomal rearrangement. One of the best-studied examples is the palindromic AT-rich repeat (PATRR), which induces recurrent constitutional translocations in humans. Here, we established a plasmid-based model that promotes frequent intermolecular rearrangements between two PATRRs in HEK293 cells. In this model system, the proportion of PATRR plasmid that extrudes a cruciform structure correlates to the levels of rearrangement. Our data suggest that PATRR-mediated translocations are attributable to unusual DNA conformations that confer a common pathway for chromosomal rearrangements in humans.

Using 3-color chromosome painting to decide between chromosome aberration models

International Nuclear Information System (INIS)

Lucas, J.N.; Sachs, R.K.

1993-01-01

Ionizing radiation produces chromosome aberrations when DNA double strand breaks (DSB) interact pairwise. For more than 30 years there have been two main, competing theories of such binary DSB interactions. The classical theory asserts that an unrepaired DSB makes two ends which separate, with each end subsequently able to join any similar (non-telomeric) end. The exchange theory asserts that the two DSB ends remain associated until repair or a reciprocal chromosome exchange involving a second DSB occurs. The authors conducted an experiment to test these models, using 3-color chromosome painting. After in vitro irradiation of resting human lymphocytes, they observed cells with three-color triplets at first metaphase: three derivative chromosomes having permuted colors, as if three broken chromosomes had played musical chairs. On the exchange model in its standard form such 3-color triplets cannot occur. On the classical model the expected frequency can be calculated. They report data and computer calculations which exclude the exchange model and favor the classical model

Chromosomal abnormalities in a psychiatric population

Energy Technology Data Exchange (ETDEWEB)

Lewis, K.E.; Lubetsky, M.J.; Wenger, S.L.; Steele, M.W. [Univ. of Pittsburgh Medical Center, PA (United States)

1995-02-27

Over a 3.5 year period of time, 345 patients hospitalized for psychiatric problems were evaluated cytogenetically. The patient population included 76% males and 94% children with a mean age of 12 years. The criteria for testing was an undiagnosed etiology for mental retardation and/or autism. Cytogenetic studies identified 11, or 3%, with abnormal karyotypes, including 4 fragile X positive individuals (2 males, 2 females), and 8 with chromosomal aneuploidy, rearrangements, or deletions. While individuals with chromosomal abnormalities do not demonstrate specific behavioral, psychiatric, or developmental problems relative to other psychiatric patients, our results demonstrate the need for an increased awareness to order chromosomal analysis and fragile X testing in those individuals who have combinations of behavioral/psychiatric, learning, communication, or cognitive disturbance. 5 refs., 1 fig., 2 tabs.

Persistence of Breakage in Specific Chromosome Bands 6 Years after Acute Exposure to Oil.

Directory of Open Access Journals (Sweden)

Alexandra Francés

251 breakpoints in exposed individuals were identified, showing a non-uniform distribution in the human ideogram. Ten chromosome bands were found to be especially prone to breakage through both statistical methods. By comparing these bands with those observed in certain exposed individuals who had already participated the previous study, it was found in both studies that four bands (2q21, 3q27, 5q31 and 17p11.2 are particularly sensitive to breakage. Additionally, the dysfunction in DNA repair mechanisms was not significantly higher in oil-exposed individuals than in non-exposed individuals.The sample size and the possibility of some kind of selection bias should be considered. Genotoxic results cannot be extrapolated to the high number of individuals who participated occasionally in clean-up tasks.Our findings show the existence of at least four target bands (2q21, 3q27, 5q31 and 17p11.2 with a greater propensity to break over time after an acute exposure to oil. The breaks in these bands, which are commonly involved in hematological cancer, may explain the increase of cancer risk reported in chronically benzene-exposed individuals. In addition, a more efficiency of the DNA repair mechanisms has been detected six years after in fishermen who were highly exposed to the oil spill. To date, only this study, performed by our group on the previous and present genotoxic effects, has analyzed the chromosomal regions affected by breakage after an acute oil exposure.

Chromosome aberrations in human lymphocytes exposed to tritiated water in vitro

International Nuclear Information System (INIS)

Bocian, E.; Ziemba-zak, B.; Rosiek, O.; Sablinski, J.

1978-01-01

The induction of chromosome aberrations in human peripheral blood lymphocytes by tritiated water or 180 kV X-rays in vitro was studied. Lymphocytes were exposed to various concentrations of HTO for 2 h or for 53 h. Chromosome and chromatid type aberrations were scored during the first mitotic division after stimulation with phytohaemagglutinin. For the analysis of the dose-response relationship the data were fitted by the method of least-squares to different models. After acute exposure to tritium β-rays and X-rays, the dicentrics + centric rings and terminal + interstitial deletions gave the best fit to the linear-quadratic function. However, data for these types of aberrations after 53 h exposure to HTO gave equally good fit to the linear and linear-quadratic functions. The best description of the dose-response relationship for chromatid aberrations is given by the linear model. In the system studied the RBE of tritium β-rays as compared to 180 KV X-rays was 1.17+-0.02. (Auth.)

Report of the first international workshop on human chromosome 14 mapping 1993

Energy Technology Data Exchange (ETDEWEB)

Cox, D.W.

1995-06-01

The first International Workshop on Human Chromosome 14 mapping was held at Novotel in Toronto, Canada on June 9-12, 1993. There were 23 participants from nine countries. The goals of the workshop were to compile physical maps and a consensus linkage map, to consolidate available data on disease loci, to catalogue and facilitate distribution of resources and to encourage new collaborations and data sharing.

Relative biological effectiveness of tritiated water on human chromosomes of lymphocytes and bone marrow cells

International Nuclear Information System (INIS)

Tanaka, Kimio; Sawada, Shozo; Kamada, Nanao

1992-01-01

One of the major toxic effluent from nuclear power industries is tritiated water (HTO), which is released into the environment in large quantities. Low dose radiation effects and dose rate effects of HTO on human lymphocytes and bone marrow cells are not well studied. The present study was performed to investigate dose-response relationship for chromosome aberration frequencies in the human lymphocytes and bone marrow cells, by HTO in-vitro exposure at low dose ranges of 0.1 to 1 Gy. Go lymphocytes and bone marrow cells were incubated for 10 - 150 minutes with HTO at 2 cGy/min. Also 60 Co γ and 137 Cs γ rays were used as controls. Dicentric chromosomes were scored in 1,000 to 2,000 cells of each experimental series. The RBE values of HTO at low dose range for the induction of dicentric chromosomes and chromatid type aberrations were 2.7 in lymphocytes and approximately 3.8 in bone marrow cells with respect to 60 Co γ ray, respectively. Also lymphocytes were chronically exposed to HTO for 24 to 72 hrs at lower dose rates (0.2 and 0.05 cGy/min). The yields of dicentrics and rings decreased with the reduction in the dose rate of HTO, presenting a clear dose rate effects of HTO. These results provide an useful information for the assessment for health risk in humans exposed to low concentration level to HTO. (author)

Sex, rebellion and decadence: the scandalous evolutionary history of the human Y chromosome.

Science.gov (United States)

Navarro-Costa, Paulo

2012-12-01

It can be argued that the Y chromosome brings some of the spirit of rock&roll to our genome. Equal parts degenerate and sex-driven, the Y has boldly rebelled against sexual recombination, one of the sacred pillars of evolution. In evolutionary terms this chromosome also seems to have adopted another of rock&roll's mottos: living fast. Yet, it appears to have refused to die young. In this manuscript the Y chromosome will be analyzed from the intersection between structural, evolutionary and functional biology. Such integrative approach will present the Y as a highly specialized product of a series of remarkable evolutionary processes. These led to the establishment of a sex-specific genomic niche that is maintained by a complex balance between selective pressure and the genetic diversity introduced by intrachromosomal recombination. Central to this equilibrium is the "polish or perish" dilemma faced by the male-specific Y genes: either they are polished by the acquisition of male-related functions or they perish via the accumulation of inactivating mutations. Thus, understanding to what extent the idiosyncrasies of Y recombination may impact this chromosome's role in sex determination and male germline functions should be regarded as essential for added clinical insight into several male infertility phenotypes. This article is part of a Special Issue entitled: Molecular Genetics of Human Reproductive Failure. Copyright © 2012 Elsevier B.V. All rights reserved.

Chromosomal damages and mutagenesis in mammalian and human cells induced by ionizing radiations with different LET

International Nuclear Information System (INIS)

Govorun, R.D.

1997-01-01

On the basis of literature and proper data the inference was made about essential role of structural chromosomal (and gene) damages in spontaneous and radiation-induced mutagenesis of mammalian and human cells on HPRT-loci. The evidences of increasing role of these damages in the mutagenesis after the influence of ionizing radiations with high LET are adduced. The consequences of HPRT-gene damages have been examined hypothetically. The geterogeneity of mutant subclones on their cytogenetical properties were revealed experimentally. The data reflect a phenomenon of the reproductive chromosomal instability in many generations of mutant cell. The mutagenesis of mammalian cells is also accompanied by the impairment of chromosome integrity with high probability as a stage of appropriate genome reorganization because of changed vital conditions

Long-range autocorrelations of CpG islands in the human genome.

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Benjamin Koester

Full Text Available In this paper, we use a statistical estimator developed in astrophysics to study the distribution and organization of features of the human genome. Using the human reference sequence we quantify the global distribution of CpG islands (CGI in each chromosome and demonstrate that the organization of the CGI across a chromosome is non-random, exhibits surprisingly long range correlations (10 Mb and varies significantly among chromosomes. These correlations of CGI summarize functional properties of the genome that are not captured when considering variation in any particular separate (and local feature. The demonstration of the proposed methods to quantify the organization of CGI in the human genome forms the basis of future studies. The most illuminating of these will assess the potential impact on phenotypic variation of inter-individual variation in the organization of the functional features of the genome within and among chromosomes, and among individuals for particular chromosomes.

Epigenetic basis of neuronal plasticity: Association with R/G-band boundaries on human chromosomes

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Yoshihisa Watanabe

2016-09-01

Full Text Available Epigenetic mechanisms have been suggested to have roles in neuroplasticity, in particular with regard to learning and memory formation, and in a range of neural diseases. In addition to epigenetic marks, the human genome also contains large-scale compartmentalized structures that might also influence neuroplasticity and neural disease. These structures result from variations in the amounts of GC% and in the timing of DNA replication and give rise to longitudinal differentiation (light and dark bands along chromosomes after the appropriate staining. Here we describe our current understanding of the biological importance of the boundaries between these light and dark bands (the so-called R/G boundaries. We propose that the R/G-band boundaries on human chromosomes can be altered by epigenetic mechanisms, and that these changes may affect neuroplasticity, which is important to memory and learning, and may also have a role in the development of neural diseases associated with genomic instability.

Induction of chromosomal aberrations in human lymphocytes by fission neutrons

International Nuclear Information System (INIS)

Silva, Marcia Augusta da; Coelho, Paulo Rogerio Pinto; Bartolini, Paolo; Okazaki, Kayo

2009-01-01

Chromosome aberrations induced by sparsely ionizing radiation (low-LET) are well known and cytogenetic analyses of irradiated human lymphocytes have been widely applied to biological dosimetry. However, much less is known about chromosome aberrations induced by densely ionizing radiation (high LET), such as that of alpha particles or neutrons. Such particles induce DNA strand breaks, as well as chromosome breakage and rearrangements of high complexity. This damage is more localized and less efficiently repaired than after X- or γ-ray irradiation. This preferential production of complex aberrations by densely ionizing radiation is related to the unique energy deposition patterns, which produces highly localized multiple DNA damage at the chromosomal level. A better knowledge of the interactions between different types of radiation and cellular DNA is of importance, not only from the radiobiological viewpoint but also for dosimetric and therapeutic purposes. The objective of the present study was to analyse the cytogenetic effects of fission neutrons on peripheral blood lymphocytes in order to evaluate structural and numerical aberrations and number of cells in the different mitotic cycles. So, blood samples from five healthy donors, 22-25 years old, of both sexes, were irradiated in the Research Reactor IEA-R1 of our Institute (IPEN/CNEN-SP) with thermal and fast neutrons at doses of 0.2; 0.3; 0.5 and 1.0 Gy. The γ contribution to the total absorbed dose was about 30%. These doses were monitored by thermoluminescent dosemeters: LiF-600 (for neutrons) and LiF-700 (for γ-rays). The data concerning structural aberrations were evaluated with regard to three parameters: percentage of cells with aberrations, number of aberrations/cell and number of dicentric/cell. The cytogenetic results showed an increase in the three parameters after irradiation with neutrons, as a function of radiation dose. Apparently, there was no influence of neutrons on the kinetics of cellular

Regulated expression of genes inserted at the human chromosomal β-globin locus by homologous recombination

International Nuclear Information System (INIS)

Nandi, A.K.; Roginski, R.S.; Gregg, R.G.; Smithies, O.; Skoultchi, A.I.

1988-01-01

The authors have examined the effect of the site of integration on the expression of cloned genes introduced into cultured erythroid cells. Smithies et al. reported the targeted integration of DNA into the human β-globin locus on chromosome 11 in a mouse erythroleukemia-human cell hybrid. These hybrid cells can undergo erythroid differentiation leading to greatly increased mouse and human β-globin synthesis. By transfection of these hybrid cells with a plasmid carrying a modified human β-globin gene and a foreign gene composed of the coding sequence of the bacterial neomycin-resistance gene linked to simian virus 40 transcription signals (SVneo), cells were obtained in which the two genes are integrated at the β-globin locus on human chromosome 11 or at random sites. When they examined the response of the integrated genes to cell differentation, they found that the genes inserted at the β-globin locus were induced during differentiation, whereas randomly positioned copies were not induced. Even the foreign SVneo gene was inducible when it had been integrated at the β-globin locus. The results show that genes introduced at the β-globin locus acquire some of the regulatory properties of globin genes during erythroid differentiation

Implications for x-chromosome regulation from studies of human x-chromosome DNA

International Nuclear Information System (INIS)

Wolf, S.F.; Migeon, B.R.

1983-01-01

It is clear that there must be multiple events involved in the regulation of the mammalian X chromosome. The initial event, occurring about the time of implantation results in inactivation of all but a single X chromosome in diploid cells. A popular working hypothesis is that DNA modification, such as methylation or sequence rearrangement, might be responsible for maintenance of the inactive state. Methylation is particularly attractive, since the preference for methylating half-methylated sites might result in perpetuation of the differentiated state. In this paper we discuss several facets of our studies of X inactivation; specifically, our general strategy, studies of X DNA methylation, and studies of loci that escape inactivation. 47 references, 8 figures, 2 tables

Induction of chromosomal aberrations in human primary fibroblasts and immortalized cancer cells exposed to extremely-low-frequency electromagnetic fields

International Nuclear Information System (INIS)

Seyyedi, S. S.; Mozdarani, H.; Rezaei Tavirani, M.; Heydari, S.

2010-01-01

Rapidly increasing possibilities of exposure to environmental extremely low-frequency electromagnetic fields have become a topic of worldwide investigation. Epidemiological and laboratory studies suggest that exposure to extremely low-frequency electromagnetic fields may increase cancer risk therefore assessment of chromosomal damage in various cell lines might be of predictive value for future risk estimation. Materials and Methods: Primary cultures of fibroblasts from human skin biopsy were exposed to continuous extremely low-frequency electromagnetic fields (3, 50 and 60 Hz, sinusoidal, 3h, and 4 m T). Also immortalized cell lines, SW480, MCF-7 and 1321N1 were exposed to continuous extremely low-frequency electromagnetic fields (50 Hz, sinusoidal, 3 h, 4 m T). Metaphase plates Were prepared according to standard methods and stained in 5% Giemsa solution. Chromosomal aberrations of both chromosome and chromatid types were scored to evaluate the effects of extremely low-frequency electromagnetic fields on primary or established cell lines. Results: Results indicate that by increasing the frequency of extremely low-frequency electromagnetic fields, chromosomal aberrations were increased up to 7-fold above background levels in primary human fibroblast cells. In addition, continuous exposure to a 50 Hz electromagnetic field led to a significant increase in chromosomal aberrations in SW480, MCF-7 and 1321N1 cell lines compared to sham control. Conclusion: Results obtained indicate that extremely low-frequency electromagnetic fields has the potential for induction of chromosomal aberrations in all cell types.

Synteny of human chromosomes 14 and 15 in the platyrrhines (Primates, Platyrrhini)

Science.gov (United States)

2009-01-01

In order to study the intra- and interspecific variability of the 14/15 association in Platyrrhini, we analyzed 15 species from 13 genera, including species that had not been described yet. The DNA libraries of human chromosomes 14 and 15 were hybridized to metaphases of Alouatta guariba clamitans, A. caraya, A. sara, Ateles paniscus chamek, Lagothrix lagothricha, Brachyteles arachnoides, Saguinus midas midas, Leontopithecus chrysomelas, Callimico goeldii, Callithrix sp., Cebus apella, Aotus nigriceps, Cacajao melanocephalus,Chiropotes satanas and Callicebus caligatus. The 14/15 hybridization pattern was present in 13 species, but not in Alouatta sara that showed a 14/15/14 pattern and Aotus nigriceps that showed a 15/14/15/14 pattern. In the majority of the species, the HSA 14 homologue retained synteny for the entire chromosome, whereas the HSA 15 homologue displayed fragmented segments. Within primates, the New World monkeys represent the taxon with the highest variability in chromosome number (2n = 16 to 62). The presence of the HSA 14/15 association in all species and subspecies studied herein confirms that this association is the ancestral condition for platyrrhines and that this association has been retained in most platyrrhines, despite the occurrence of extensive inter- and intrachromosomal rearrangements in this infraorder of Primates. PMID:21637455

Synteny of human chromosomes 14 and 15 in the platyrrhines (Primates, Platyrrhini

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Cristiani Gifalli-Iughetti

2009-01-01

Full Text Available In order to study the intra- and interspecific variability of the 14/15 association in Platyrrhini, we analyzed 15 species from 13 genera, including species that had not been described yet. The DNA libraries of human chromosomes 14 and 15 were hybridized to metaphases of Alouatta guariba clamitans, A. caraya, A. sara, Ateles paniscus chamek, Lagothrix lagothricha, Brachyteles arachnoides, Saguinus midas midas, Leontopithecus chrysomelas, Callimico goeldii, Callithrix sp., Cebus apella, Aotus nigriceps, Cacajao melanocephalus, Chiropotes satanas and Callicebus caligatus. The 14/15 hybridization pattern was present in 13 species, but not in Alouatta sara that showed a 14/15/14 pattern and Aotus nigriceps that showed a 15/14/15/14 pattern. In the majority of the species, the HSA 14 homologue retained synteny for the entire chromosome, whereas the HSA 15 homologue displayed fragmented segments. Within primates, the New World monkeys represent the taxon with the highest variability in chromosome number (2n = 16 to 62. The presence of the HSA 14/15 association in all species and subspecies studied herein confirms that this association is the ancestral condition for platyrrhines and that this association has been retained in most platyrrhines, despite the occurrence of extensive inter- and intrachromosomal rearrangements in this infraorder of Primates.

Synteny of human chromosomes 14 and 15 in the platyrrhines (Primates, Platyrrhini).

Science.gov (United States)

Gifalli-Iughetti, Cristiani; Koiffmann, Célia P

2009-10-01

In order to study the intra- and interspecific variability of the 14/15 association in Platyrrhini, we analyzed 15 species from 13 genera, including species that had not been described yet. The DNA libraries of human chromosomes 14 and 15 were hybridized to metaphases of Alouatta guariba clamitans, A. caraya, A. sara, Ateles paniscus chamek, Lagothrix lagothricha, Brachyteles arachnoides, Saguinus midas midas, Leontopithecus chrysomelas, Callimico goeldii, Callithrix sp., Cebus apella, Aotus nigriceps, Cacajao melanocephalus,Chiropotes satanas and Callicebus caligatus. The 14/15 hybridization pattern was present in 13 species, but not in Alouatta sara that showed a 14/15/14 pattern and Aotus nigriceps that showed a 15/14/15/14 pattern. In the majority of the species, the HSA 14 homologue retained synteny for the entire chromosome, whereas the HSA 15 homologue displayed fragmented segments. Within primates, the New World monkeys represent the taxon with the highest variability in chromosome number (2n = 16 to 62). The presence of the HSA 14/15 association in all species and subspecies studied herein confirms that this association is the ancestral condition for platyrrhines and that this association has been retained in most platyrrhines, despite the occurrence of extensive inter- and intrachromosomal rearrangements in this infraorder of Primates.

Computational Analysis of G-Quadruplex Forming Sequences across Chromosomes Reveals High Density Patterns Near the Terminal Ends.

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Julia H Chariker

Full Text Available G-quadruplex structures (G4 are found throughout the human genome and are known to play a regulatory role in a variety of molecular processes. Structurally, they have many configurations and can form from one or more DNA strands. At the gene level, they regulate gene expression and protein synthesis. In this paper, chromosomal-level patterns of distribution are analyzed on the human genome to identify high-level distribution patterns potentially related to global functional processes. Here we show unique high density banding patterns on individual chromosomes that are highly correlated, appearing in a mirror pattern, across forward and reverse DNA strands. The highest density of G4 sequences occurs within four megabases of one end of most chromosomes and contains G4 motifs that bind with zinc finger proteins. These findings suggest that G4 may play a role in global chromosomal processes such as those found in meiosis.

Nucleotide, cytogenetic and expression impact of the human chromosome 8p23.1 inversion polymorphism.

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Bosch, Nina; Morell, Marta; Ponsa, Immaculada; Mercader, Josep Maria; Armengol, Lluís; Estivill, Xavier

2009-12-14

The human chromosome 8p23.1 region contains a 3.8-4.5 Mb segment which can be found in different orientations (defined as genomic inversion) among individuals. The identification of single nucleotide polymorphisms (SNPs) tightly linked to the genomic orientation of a given region should be useful to indirectly evaluate the genotypes of large genomic orientations in the individuals. We have identified 16 SNPs, which are in linkage disequilibrium (LD) with the 8p23.1 inversion as detected by fluorescent in situ hybridization (FISH). The variability of the 8p23.1 orientation in 150 HapMap samples was predicted using this set of SNPs and was verified by FISH in a subset of samples. Four genes (NEIL2, MSRA, CTSB and BLK) were found differentially expressed (pinversion occurred. Moreover, an impact of 8p23.1 inversion on gene expression levels cannot be ruled out, since four genes from this region have statistically significant different expression levels depending on the inversion status. FISH results in lymphoblastoid cell lines suggest the presence of mosaicism regarding the 8p23.1 inversion.

Human MLH1 suppresses the insertion of telomeric sequences at intra-chromosomal sites in telomerase-expressing cells

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Jia, Pingping; Chastain, Megan; Zou, Ying; Her, Chengtao

2017-01-01

Abstract Aberrant formation of interstitial telomeric sequences (ITSs) promotes genome instabilities. However, it is unclear how aberrant ITS formation is suppressed in human cells. Here, we report that MLH1, a key protein involved in mismatch repair (MMR), suppresses telomeric sequence insertion (TSI) at intra-chromosomal regions. The frequency of TSI can be elevated by double-strand break (DSB) inducer and abolished by ATM/ATR inhibition. Suppression of TSI requires MLH1 recruitment to DSBs, indicating that MLH1's role in DSB response/repair is important for suppressing TSI. Moreover, TSI requires telomerase activity but is independent of the functional status of p53 and Rb. Lastly, we show that TSI is associated with chromosome instabilities including chromosome loss, micronuclei formation and chromosome breakage that are further elevated by replication stress. Our studies uncover a novel link between MLH1, telomerase, telomere and genome stability. PMID:28180301

Human tissue factor: cDNA sequence and chromosome localization of the gene

International Nuclear Information System (INIS)

Scarpati, E.M.; Wen, D.; Broze, G.J. Jr.; Miletich, J.P.; Flandermeyer, R.R.; Siegel, N.R.; Sadler, J.E.

1987-01-01

A human placenta cDNA library in λgt11 was screened for the expression of tissue factor antigens with rabbit polyclonal anti-human tissue factor immunoglobulin G. Among 4 million recombinant clones screened, one positive, λHTF8, expressed a protein that shared epitopes with authentic human brain tissue factor. The 1.1-kilobase cDNA insert of λHTF8 encoded a peptide that contained the amino-terminal protein sequence of human brain tissue factor. Northern blotting identified a major mRNA species of 2.2 kilobases and a minor species of ∼ 3.2 kilobases in poly(A) + RNA of placenta. Only 2.2-kilobase mRNA was detected in human brain and in the human monocytic U937 cell line. In U937 cells, the quantity of tissue factor mRNA was increased several fold by exposure of the cells to phorbol 12-myristate 13-acetate. Additional cDNA clones were selected by hybridization with the cDNA insert of λHTF8. These overlapping isolates span 2177 base pairs of the tissue factor cDNA sequence that includes a 5'-noncoding region of 75 base pairs, an open reading frame of 885 base pairs, a stop codon, a 3'-noncoding region of 1141 base pairs, and a poly(a) tail. The open reading frame encodes a 33-kilodalton protein of 295 amino acids. The predicted sequence includes a signal peptide of 32 or 34 amino acids, a probable extracellular factor VII binding domain of 217 or 219 amino acids, a transmembrane segment of 23 acids, and a cytoplasmic tail of 21 amino acids. There are three potential glycosylation sites with the sequence Asn-X-Thr/Ser. The 3'-noncoding region contains an inverted Alu family repetitive sequence. The tissue factor gene was localized to chromosome 1 by hybridization of the cDNA insert of λHTF8 to flow-sorted human chromosomes

Inherited chromosomally integrated human herpesvirus 6 as a predisposing risk factor for the development of angina pectoris.

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Gravel, Annie; Dubuc, Isabelle; Morissette, Guillaume; Sedlak, Ruth H; Jerome, Keith R; Flamand, Louis

2015-06-30

Inherited chromosomally integrated human herpesvirus-6 (iciHHV-6) results in the germ-line transmission of the HHV-6 genome. Every somatic cell of iciHHV-6+ individuals contains the HHV-6 genome integrated in the telomere of chromosomes. Whether having iciHHV-6 predisposes humans to diseases remains undefined. DNA from 19,597 participants between 40 and 69 years of age were analyzed by quantitative PCR (qPCR) for the presence of iciHHV-6. Telomere lengths were determined by qPCR. Medical records, hematological, biochemical, and anthropometric measurements and telomere lengths were compared between iciHHV-6+ and iciHHV-6- subjects. The prevalence of iciHHV-6 was 0.58%. Two-way ANOVA with a Holm-Bonferroni correction was used to determine the effects of iciHHV6, sex, and their interaction on continuous outcomes. Two-way logistic regression with a Holm-Bonferroni correction was used to determine the effects of iciHHV6, sex, and their interaction on disease prevalence. Of 50 diseases monitored, a single one, angina pectoris, is significantly elevated (3.3×) in iciHHV-6+ individuals relative to iciHHV-6- subjects (P = 0.017; 95% CI, 1.73-6.35). When adjusted for potential confounding factors (age, body mass index, percent body fat, and systolic blood pressure), the prevalence of angina remained three times greater in iciHHV-6+ subjects (P = 0.015; 95%CI, 1.23-7.15). Analyses of telomere lengths between iciHHV-6- without angina, iciHHV-6- with angina, and iciHHV-6+ with angina indicate that iciHHV-6+ with angina have shorter telomeres than age-matched iciHHV-6- subjects (P = 0.006). Our study represents, to our knowledge, the first large-scale analysis of disease association with iciHHV-6. Our results are consistent with iciHHV-6 representing a risk factor for the development of angina.

Fluorescence in situ hybridization on human metaphase chromosomes detected by near-field scanning optical microscopy

NARCIS (Netherlands)

Moers, M.H.P.; Moers, M.H.P.; Kalle, W.H.J.; Kalle, W.H.J.; Ruiter, A.G.T.; Wiegant, J.C.A.G.; Raap, A.K.; Greve, Jan; de Grooth, B.G.; van Hulst, N.F.

1996-01-01

Fluorescence in situ hybridization o­n human metaphase chromosomes is detected by near-field scanning optical microscopy. This combination of cytochemical and scanning probe techniques enables the localization and identification of several fluorescently labelled genomic DNA fragments o­n a single

Intergenic DNA sequences from the human X chromosome reveal high rates of global gene flow

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Wall Jeffrey D

2008-11-01

Full Text Available Abstract Background Despite intensive efforts devoted to collecting human polymorphism data, little is known about the role of gene flow in the ancestry of human populations. This is partly because most analyses have applied one of two simple models of population structure, the island model or the splitting model, which make unrealistic biological assumptions. Results Here, we analyze 98-kb of DNA sequence from 20 independently evolving intergenic regions on the X chromosome in a sample of 90 humans from six globally diverse populations. We employ an isolation-with-migration (IM model, which assumes that populations split and subsequently exchange migrants, to independently estimate effective population sizes and migration rates. While the maximum effective size of modern humans is estimated at ~10,000, individual populations vary substantially in size, with African populations tending to be larger (2,300–9,000 than non-African populations (300–3,300. We estimate mean rates of bidirectional gene flow at 4.8 × 10-4/generation. Bidirectional migration rates are ~5-fold higher among non-African populations (1.5 × 10-3 than among African populations (2.7 × 10-4. Interestingly, because effective sizes and migration rates are inversely related in African and non-African populations, population migration rates are similar within Africa and Eurasia (e.g., global mean Nm = 2.4. Conclusion We conclude that gene flow has played an important role in structuring global human populations and that migration rates should be incorporated as critical parameters in models of human demography.

Deletion of DXZ4 on the human inactive X chromosome alters higher-order genome architecture.

Science.gov (United States)

Darrow, Emily M; Huntley, Miriam H; Dudchenko, Olga; Stamenova, Elena K; Durand, Neva C; Sun, Zhuo; Huang, Su-Chen; Sanborn, Adrian L; Machol, Ido; Shamim, Muhammad; Seberg, Andrew P; Lander, Eric S; Chadwick, Brian P; Aiden, Erez Lieberman

2016-08-02

During interphase, the inactive X chromosome (Xi) is largely transcriptionally silent and adopts an unusual 3D configuration known as the "Barr body." Despite the importance of X chromosome inactivation, little is known about this 3D conformation. We recently showed that in humans the Xi chromosome exhibits three structural features, two of which are not shared by other chromosomes. First, like the chromosomes of many species, Xi forms compartments. Second, Xi is partitioned into two huge intervals, called "superdomains," such that pairs of loci in the same superdomain tend to colocalize. The boundary between the superdomains lies near DXZ4, a macrosatellite repeat whose Xi allele extensively binds the protein CCCTC-binding factor. Third, Xi exhibits extremely large loops, up to 77 megabases long, called "superloops." DXZ4 lies at the anchor of several superloops. Here, we combine 3D mapping, microscopy, and genome editing to study the structure of Xi, focusing on the role of DXZ4 We show that superloops and superdomains are conserved across eutherian mammals. By analyzing ligation events involving three or more loci, we demonstrate that DXZ4 and other superloop anchors tend to colocate simultaneously. Finally, we show that deleting DXZ4 on Xi leads to the disappearance of superdomains and superloops, changes in compartmentalization patterns, and changes in the distribution of chromatin marks. Thus, DXZ4 is essential for proper Xi packaging.

A molecular deletion of distal chromosome 4p in two families with a satellited chromosome 4 lacking the Wolf-Hirschhorn syndrome phenotype.

Science.gov (United States)

Estabrooks, L L; Lamb, A N; Kirkman, H N; Callanan, N P; Rao, K W

1992-11-01

We report two families with a satellited chromosome 4 short arm (4ps). Satellites and stalks normally occur on the short arms of acrocentric chromosomes; however, the literature cites several reports of satellited nonacrocentric chromosomes, which presumably result from a translocation with an acrocentric chromosome. This is the first report of 4ps chromosomes. Our families are remarkable in that both unaffected and affected individuals carry the 4ps chromosome. The phenotypes observed in affected individuals, although dissimilar, were sufficient to encourage a search for a deletion of chromosome 4p. By Southern blot analysis and fluorescence in situ hybridization, a deletion of material mapping approximately 150 kb from chromosome 4pter was discovered. This deletion is notable because it does not result in the Wolf-Hirschhorn syndrome and can result in an apparently normal phenotype. We speculate that homology between subterminal repeat sequences on 4p and sequences on the acrocentric short arms may explain the origin of the rearrangement and that position effect may play a role in the expression of the abnormal phenotype.

Biological effects of tritiated water in low concentration of human lymphocyte chromosome

International Nuclear Information System (INIS)

Tanaka, K.; Kamada, N.; Sawaeda, S.

1992-01-01

This study was undertaken to investigate the dose-response relationship of tritiated water (HTO) for chromosome aberration in the human lymphocytes, at low dose in vitro exposure ranging from 0.1-1 Gy. The Relative Biological Effectiveness values of HTO with respect to 60 Co gamma ray at a dose rate of 2 cGy/min(15 mCi/ml), at low dose range for the induction of dicentric and centric ring chromosomes were 2.7 in lymphocytes. Also lymphocytes were chronically exposed to HTO for 67 to 80 hrs at different lower dose rates (0.5 and 0.02 cGy/min). There was a 77% decrease in the yields of dicentrics and centric rings, at the dose rate of 0.02cGy/min of HTO, presenting a clear dose rate effect of HTO. The RBE value of HTO relative to 137 Cs gamma ray was 2.0 at the dose rate of 0.02cGy/min(0.15mCi/ml). This suggests that a higher dose rate of HTO exposure has a higher risk and a decrease of RBE value at low dose rate. These results provide useful information for the assessment of health risks in humans specially exposed to low concentration of HTO. (author). 6 refs., 2 figs

The use of unstable chromosome aberrations and micronuclei in the individual biomonitoring: a comparative study; Emprego das aberracoes cromossomicas instaveis e micronucleos no biomonitoramento individual: estudo comparativo

Energy Technology Data Exchange (ETDEWEB)

Fernandes, Thiago de Salazar e

2005-02-15

Biodosimetry is based on the investigation of radioinduced biological effects in order to correlate them with the absorbed dose. The quantification of unstable chromosome aberrations and micronuclei, in peripheral blood lymphocytes, are two methods commonly used in biodosimetry. In this context, the aim of this research was to compare these methods in the biomonitoring of health care professionals occupationally exposed to ionizing radiation. In parallel, the technique of C-banding was evaluated for quality control of unstable chromosome aberrations analyses. Thus, samples of peripheral blood from health care professionals of three hospitals from Recife (Brazil) were collected, and the lymphocytes cultures were carried out based on the cytogenetic classical technique. It was pointed out that analysis of micronuclei is faster than the unstable chromosome aberrations ones, which suggests the use of the former in preliminary evaluation in cases of suspected accidental exposure. C-banding technique was efficient, as confirmatory test, in the identification of dicentrics and rings during the analyses of unstable chromosome aberrations, being able to be applied in the quality control in biodosimetry. The comparison between the individual work conditions with the frequencies of unstable aberrations and micronuclei obtained from cytogenetic analysis, resulted in the change of behavior of the professionals involved in this research, with a better observance of the radioprotection standards. (author)

Analysis of the frequency of unstable chromosome aberrations in human lymphocytes irradiated with 60Co

International Nuclear Information System (INIS)

Mendonca, Julyanne C.G.; Mendes, Mariana E.; Lima, Fabiana F.; Santos, Neide

2013-01-01

The aim of this study was to analyze the frequency of unstable chromosomal aberrations induced by gamma radiation from a 60 Co source at two different doses. Samples were obtained from a healthy donor and exposed to 60 Co source (Gammacel 220 ) located in the Department of Nuclear Energy of Pernambuco Federal University (DEN/UFPe/Brazil) with a rate of air Kerma to 3,277 Gy/h. Exposures resulted in absorbed dose 0.51 Gy and 0.77 Gy. Mitotic metaphases were obtained by culturing lymphocytes for chromosome analysis and the slides were stained with 5% Giemsa. Among the unstable chromosomal aberrations the dicentric chromosomes, ring chromosomes and acentric fragments were analyzed. To calculate the significance level the chi - square test was used, considering relevant differences between the frequencies when the value of p < 0.05. To calculate the significance level of the chi - square test was used, considering relevant differences between the frequencies when the value of p < 0.05. The results showed that there was significant difference of the frequencies of dicentric chromosomes (from 0.18 to 0.51 to 0.37 Gy to 0.77 Gy), however there was no statistically significant difference between the frequencies of acentric fragments ( 0.054 to 0, 51 Gy to 0.063 to 0.77 Gy) and ring chromosomes (0.001 to 0.51 Gy to 0.003 to 0.77 Gy). The low number of rings is found justified, considering that in irradiated human lymphocytes, its appearance is rare relative to dicentrics. The results confirm that dicentrics are the most reliable biomarkers in estimating dose after exposure to gamma radiation. These two points will make the calibration curve dose-response being built for Biological Dosimetry Laboratory of CRCN-NE/CNEN

Radiation exposure and chromosome abnormalities. Human cytogenetic studies at the National Institute of Radiological Sciences, Japan, 1963-1988

International Nuclear Information System (INIS)

Ishihara, T.; Kohno, S.; Minamihisamatsu, M.

1990-01-01

The results of human cytogenetic studies performed at the National Institute of Radiological Sciences (NIRS), Chiba, Japan for about 25 years are described. The studies were pursued primarily under two major projects: one involving people exposed to radiation under various conditions and the other involving patients with malignant diseases, especially leukemias. Whereas chromosome abnormalities in radiation-exposed people are excellent indicators of radiation exposure, their behavior in bone marrow provide useful information for a better understanding of chromosome abnormalities in leukemias and related disorders. The role of chromosome abnormalities in the genesis and development of leukemia and related disorders is considered, suggesting a view for future studies in this field

Chromosomal aberrations induced by low-dose γ-irradiation: Study of R-banded chromosomes of human lymphocytes

International Nuclear Information System (INIS)

Al-Achkar, W.; Lefrancois, D.; Aurias, A.

1991-01-01

The effect of low-dose (0-0.5 Gy) γ-radiations was studied on R-banded chromosomes from lymphocytes of healthy donors of various ages. In cells from newborns, an increase of chromosome damage roughly proportional to the dose was found. In lymphocytes from young adults chromosomal aberrations were not detected at doses of 0.05 and 0.1 Gy, and in lymphocytes from old adults not even at 0.2 Gy. The difficulty in detecting aberrations in lymphocytes from adults is largely due to a considerable background of chromosomal anomalies which should be borne in mind in dosimetry studies. The rate of induction largely depends on the types of rearrangements. One-break terminal deletions are efficiently induced at 0.1 and 0.2 Gy and are the best indicators of exposure at these doses. At 0.5 Gy, the frequencies of 2-break lesions, i.e., dicentrics and reciprocal translocations, increase, whereas the of deletions decreases. (author). 6 refs., 3 figs., 2 tabs

First-trimester maternal serum human thyroid-stimulating hormone in chromosomally normal and Down syndrome pregnancies

NARCIS (Netherlands)

Pratt, JJ; de Wolf, BTHM; Mantingh, A

Maternal serum human thyroid-stimulating hormone (TSH) levels were investigated in chromosomally normal and Down syndrome pregnancies to determine whether TSH can be used as a marker for Down syndrome in the first trimester. Measurements were conducted on stored serum samples collected from 23 Down

Are There Knots in Chromosomes?

Directory of Open Access Journals (Sweden)

Jonathan T. Siebert

2017-08-01

Full Text Available Recent developments have for the first time allowed the determination of three-dimensional structures of individual chromosomes and genomes in nuclei of single haploid mouse embryonic stem (ES cells based on Hi–C chromosome conformation contact data. Although these first structures have a relatively low resolution, they provide the first experimental data that can be used to study chromosome and intact genome folding. Here we further analyze these structures and provide the first evidence that G1 phase chromosomes are knotted, consistent with the fact that plots of contact probability vs sequence separation show a power law dependence that is intermediate between that of a fractal globule and an equilibrium structure.

Telomerase-mediated life-span extension of human primary fibroblasts by human artificial chromosome (HAC) vector

International Nuclear Information System (INIS)

Shitara, Shingo; Kakeda, Minoru; Nagata, Keiko; Hiratsuka, Masaharu; Sano, Akiko; Osawa, Kanako; Okazaki, Akiyo; Katoh, Motonobu; Kazuki, Yasuhiro; Oshimura, Mitsuo; Tomizuka, Kazuma

2008-01-01

Telomerase-mediated life-span extension enables the expansion of normal cells without malignant transformation, and thus has been thought to be useful in cell therapies. Currently, integrating vectors including the retrovirus are used for human telomerase reverse transcriptase (hTERT)-mediated expansion of normal cells; however, the use of these vectors potentially causes unexpected insertional mutagenesis and/or activation of oncogenes. Here, we established normal human fibroblast (hPF) clones retaining non-integrating human artificial chromosome (HAC) vectors harboring the hTERT expression cassette. In hTERT-HAC/hPF clones, we observed the telomerase activity and the suppression of senescent-associated SA-β-galactosidase activity. Furthermore, the hTERT-HAC/hPF clones continued growing beyond 120 days after cloning, whereas the hPF clones retaining the silent hTERT-HAC senesced within 70 days. Thus, hTERT-HAC-mediated episomal expression of hTERT allows the extension of the life-span of human primary cells, implying that gene delivery by non-integrating HAC vectors can be used to control cellular proliferative capacity of primary cultured cells

Peopling of the North Circumpolar Region--insights from Y chromosome STR and SNP typing of Greenlanders.

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Jill Katharina Olofsson

Full Text Available The human population in Greenland is characterized by migration events of Paleo- and Neo-Eskimos, as well as admixture with Europeans. In this study, the Y-chromosomal variation in male Greenlanders was investigated in detail by typing 73 Y-chromosomal single nucleotide polymorphisms (Y-SNPs and 17 Y-chromosomal short tandem repeats (Y-STRs. Approximately 40% of the analyzed Greenlandic Y chromosomes were of European origin (I-M170, R1a-M513 and R1b-M343. Y chromosomes of European origin were mainly found in individuals from the west and south coasts of Greenland, which is in agreement with the historic records of the geographic placements of European settlements in Greenland. Two Inuit Y-chromosomal lineages, Q-M3 (xM19, M194, L663, SA01 and L766 and Q-NWT01 (xM265 were found in 23% and 31% of the male Greenlanders, respectively. The time to the most recent common ancestor (TMRCA of the Q-M3 lineage of the Greenlanders was estimated to be between 4,400 and 10,900 years ago (y. a. using two different methods. This is in agreement with the theory that the North Circumpolar Region was populated via a second expansion of humans in the North American continent. The TMRCA of the Q-NWT01 (xM265 lineage in Greenland was estimated to be between 7,000 and 14,300 y. a. using two different methods, which is older than the previously reported TMRCA of this lineage in other Inuit populations. Our results indicate that Inuit individuals carrying the Q-NWT01 (xM265 lineage may have their origin in the northeastern parts of North America and could be descendants of the Dorset culture. This in turn points to the possibility that the current Inuit population in Greenland is comprised of individuals of both Thule and Dorset descent.

Isolation of probes specific to human chromosomal region 6p21 from immunoselected irradiation-fusion gene transfer hybrids

International Nuclear Information System (INIS)

Ragoussis, J.; Jones, T.A.; Sheer, D.; Shrimpton, A.E.; Goodfellow, P.N.; Trowsdale, J.; Ziegler, A.

1991-01-01

A hybrid cell line (R21/B1) containing a truncated human chromosome 6 (6pter-6q21) and a human Y chromosome on a hamster background was irradiated and fused to A23 (TK-) or W3GH (HPRT-) hamster cells. Clones containing expressed HLA class I genes (4/40) were selected using monoclonal antibodies. These clones were recloned and analyzed with a panel of probes from the HLA region. One hybrid (4G6) contained the entire HLA complex. Two other hybrids (4J4 and 4H2) contained only the HLA class I region, while the fourth hybrid (5P9) contained HLA class I and III genes in addition to other genes located in the 6p21 chromosomal region. In situ hybridization showed that the hybrid cells contained more than one fragment of human DNA. Alu and LINE PCR products were derived from these cells and compared to each other as well as to products from two somatic cell hybrids having the 6p21 region in common. The PCR fragments were then screened on conventional Southern blots of the somatic cell hybrids to select a panel of novel probes encompassing the 6p21 region. In addition, the origin of the human DNA fragments in hybrid 4J4 was determined by regional mapping of PCR products

The genome of Nectria haematococca: contribution of supernumerary chromosomes to gene expansion.

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Jeffrey J Coleman

2009-08-01

Full Text Available The ascomycetous fungus Nectria haematococca, (asexual name Fusarium solani, is a member of a group of >50 species known as the "Fusarium solani species complex". Members of this complex have diverse biological properties including the ability to cause disease on >100 genera of plants and opportunistic infections in humans. The current research analyzed the most extensively studied member of this complex, N. haematococca mating population VI (MPVI. Several genes controlling the ability of individual isolates of this species to colonize specific habitats are located on supernumerary chromosomes. Optical mapping revealed that the sequenced isolate has 17 chromosomes ranging from 530 kb to 6.52 Mb and that the physical size of the genome, 54.43 Mb, and the number of predicted genes, 15,707, are among the largest reported for ascomycetes. Two classes of genes have contributed to gene expansion: specific genes that are not found in other fungi including its closest sequenced relative, Fusarium graminearum; and genes that commonly occur as single copies in other fungi but are present as multiple copies in N. haematococca MPVI. Some of these additional genes appear to have resulted from gene duplication events, while others may have been acquired through horizontal gene transfer. The supernumerary nature of three chromosomes, 14, 15, and 17, was confirmed by their absence in pulsed field gel electrophoresis experiments of some isolates and by demonstrating that these isolates lacked chromosome-specific sequences found on the ends of these chromosomes. These supernumerary chromosomes contain more repeat sequences, are enriched in unique and duplicated genes, and have a lower G+C content in comparison to the other chromosomes. Although the origin(s of the extra genes and the supernumerary chromosomes is not known, the gene expansion and its large genome size are consistent with this species' diverse range of habitats. Furthermore, the presence of unique

The genome of Nectria haematococca: contribution of supernumerary chromosomes to gene expansion

Energy Technology Data Exchange (ETDEWEB)

Coleman, J.J.; Rounsley, S.D.; Rodriguez-Carres, M.; Kuo, A.; Wasmann, C.c.; Grimwood, J.; Schmutz, J.; Taga, M.; White, G.J.; Zhuo, S.; Schwartz, D.C.; Freitag, M.; Ma, L.-J.; Danchin, E.G.J.; Henrissat, B.; Cutinho, P.M.; Nelson, D.R.; Straney, D.; Napoli, C.A.; Baker, B.M.; Gribskov, M.; Rep, M.; Kroken, S.; Molnar, I.; Rensing, C.; Kennell, J.C.; Zamora, J.; Farman, M.L.; Selker, E.U.; Salamov, A.; Shapiro, H.; Pangilinan, J.; Lindquist, E.; Lamers, C.; Grigoriev, I.V.; Geiser, D.M.; Covert, S.F.; Temporini, S.; VanEtten, H.D.

2009-04-20

The ascomycetous fungus Nectria haematococca, (asexual name Fusarium solani), is a member of a group of .50 species known as the"Fusarium solani species complex". Members of this complex have diverse biological properties including the ability to cause disease on .100 genera of plants and opportunistic infections in humans. The current research analyzed the most extensively studied member of this complex, N. haematococca mating population VI (MPVI). Several genes controlling the ability of individual isolates of this species to colonize specific habitats are located on supernumerary chromosomes. Optical mapping revealed that the sequenced isolate has 17 chromosomes ranging from 530 kb to 6.52 Mb and that the physical size of the genome, 54.43 Mb, and the number of predicted genes, 15,707, are among the largest reported for ascomycetes. Two classes of genes have contributed to gene expansion: specific genes that are not found in other fungi including its closest sequenced relative, Fusarium graminearum; and genes that commonly occur as single copies in other fungi but are present as multiple copies in N. haematococca MPVI. Some of these additional genes appear to have resulted from gene duplication events, while others may have been acquired through horizontal gene transfer. The supernumerary nature of three chromosomes, 14, 15, and 17, was confirmed by their absence in pulsed field gel electrophoresis experiments of some isolates and by demonstrating that these isolates lacked chromosome-specific sequences found on the ends of these chromosomes. These supernumerary chromosomes contain more repeat sequences, are enriched in unique and duplicated genes, and have a lower G+C content in comparison to the other chromosomes. Although the origin(s) of the extra genes and the supernumerary chromosomes is not known, the gene expansion and its large genome size are consistent with this species' diverse range of habitats. Furthermore, the presence of unique genes on

The study of chromosome aberration yield in human lymphocytes as an indicator of radiation dose. 1. Techniques

International Nuclear Information System (INIS)

Purrott, R.J.; Lloyd, D.C.

1972-08-01

Estimates of exposure to ionizing radiation can be obtained by determining the yield of chromosome aberrations in cultured human lymphocytes. Chromosomes can only be conveniently examined during cell division. The lymphocytes, which do not normally divide whilst circulating, are stimulated to divide during a 48-hour culture period. Two types of culture technique are described, one of which employs a lymphocyte-enriched inoculum and the other which uses whole blood. After culture the cells are harvested, dispensed onto slides and prepared for microscopic examination. An account is also given of the analysis of various types of radiation-induced chromosome aberrations and of the construction of calibration curves for certain types and rates of radiation which are used to interpret the aberration yields in terms of dose. (author)

Cloning and sequencing of cDNA encoding human DNA topoisomerase II and localization of the gene to chromosome region 17q21-22

International Nuclear Information System (INIS)

Tsai-Pflugfelder, M.; Liu, L.F.; Liu, A.A.; Tewey, K.M.; Whang-Peng, J.; Knutsen, T.; Huebner, K.; Croce, C.M.; Wang, J.C.

1988-01-01

Two overlapping cDNA clones encoding human DNA topoisomerase II were identified by two independent methods. In one, a human cDNA library in phage λ was screened by hybridization with a mixed oligonucleotide probe encoding a stretch of seven amino acids found in yeast and Drosophila DNA topoisomerase II; in the other, a different human cDNA library in a λgt11 expression vector was screened for the expression of antigenic determinants that are recognized by rabbit antibodies specific to human DNA topoisomerase II. The entire coding sequences of the human DNA topoisomerase II gene were determined from these and several additional clones, identified through the use of the cloned human TOP2 gene sequences as probes. Hybridization between the cloned sequences and mRNA and genomic DNA indicates that the human enzyme is encoded by a single-copy gene. The location of the gene was mapped to chromosome 17q21-22 by in situ hybridization of a cloned fragment to metaphase chromosomes and by hybridization analysis with a panel of mouse-human hybrid cell lines, each retaining a subset of human chromosomes

Chromosomal instability induced by ionizing radiation

International Nuclear Information System (INIS)

Morgan, W.F.; Marder, B.A.; Day, J.P.

1995-01-01

There is accumulating evidence indicating genomic instability can manifest multiple generations after cellular exposure to DNA damaging agents. For instance, some cells surviving exposure to ionizing radiations show delayed reproductive cell death, delayed mutation and / or delayed chromosomal instability. Such instability, especially chromosome destabilization has been implicated in mutation, gene amplification, cellular transformation, and cell killing. To investigate chromosomal instability following DNA damage, we have used fluorescence in situ hybridization to detect chromosomal rearrangements in a human/hamster somatic hybrid cell line following exposure to ionizing radiation. Delayed chromosomal instability was detected when multiple populations of uniquely arranged metaphases were observed in clonal isolates raised from single cells. The relationship between delayed chromosomal destabilization and other endpoints of genomic instability, namely; delayed mutation and gene amplification will be discussed, as will the potential cytogenetic and molecular mechanisms contributing to delayed chromosomal instability

Introduction of a normal human chromosome 8 corrects abnormal phenotypes of Werner syndrome cells immortalized by expressing an hTERT gene

International Nuclear Information System (INIS)

Ariyoshi, Kentaro; Kodama, Seiji; Suzuki, Keiji; Goto, Makoto; Oshimura, Mitsuo; Ishizaki, Kanji; Watanabe, Masami

2009-01-01

Werner syndrome (WS) is an autosomal recessive disease characterized by premature aging and caused by mutations of the WRN gene mapped at 8p12. To examine functional complementation of WS phenotypes, we introduced a normal human chromosome 8 into a strain of WS fibroblasts (WS3RGB) immortalized by expressing a human telomerase reverse transcriptase subunit (hTERT) gene. Here, we demonstrate that the abnormal WS phenotypes including cellular sensitivities to 4-nitroquinoline-1-oxide (4NQO) and hydroxy urea (HU), and chromosomal radiosensitivity at G 2 phase are corrected by expression of the WRN gene mediated by introducing a chromosome 8. This indicates that those multiple abnormal WS phenotypes are derived from a primary, but not secondary, defect in the WRN gene. (author)

Types of structural chromosome aberrations and their incidences in human spermatozoa X-irradiated in vitro

Energy Technology Data Exchange (ETDEWEB)

Kamiguchi, Yujiroh; Tateno, Hiroyuki; Mikamo, Kazuya (Asahikawa Medical College (Japan). Department of Biological Sciences)

1990-02-01

The authors studied the effects of in vitro X-irradiation on human sperm chromosomes, using our interspecific in vitro fertilization system between human spermatozoa and zona-free hamster oocytes. 28 semen samples from 5 healthy men were exposed to 0.23, 0.45, 0.91 and 1.82 Gy of X-rays. Totals of 2098 and 2862 spermatozoa were karyotyped in the control and the irradiated groups, respectively. The indicence of spermatozoa with X-ray-induced structural chromosome aberrations (Y) increased linearly with increasing dosage (D), being best expressed by the equation, Y = 0.08 + 34.52 D. The incidence of breakage-type aberrations was moe than 9 times higher than that of exchange-type aberrations. Both of them showed linear dose-dependent increases, which were expressed by the regression lines, Y = -0.014 + 0.478 D and Y -0.010 + 0.057 D, respectively. The incidence of chromosome-ltype aberrations was about 6 times higher than that of chromatid-type aberrations. Their dose-dependent increases were expressed by the regression lines, Y = -0.015 + 0.462 D and Y = -0.006 + 0.079 D, respectively. These results are discussed in relation to the previous data obtained with {gamma}-rays. The repair mechanism of X-ray-induced sperm DNA lesions is also discussed. (author). 21 refs.; 4 figs.; 4 tabs.

Partial isodisomy for maternal chromosome 7 and short stature in an individual with a mutation at the COL1A2 locus

Energy Technology Data Exchange (ETDEWEB)

Spotila, L.D.; Sereda, L.; Prockop, D.J. (Jefferson Medical College, Philadelphia, PA (United States))

1992-12-01

Uniparental disomy for chromosome 7 has been described previously in two individuals with cystic fibrosis. Here, the authors describe a third case that was discovered because the proband was homozygous for a mutation in the COL1A2 gene for type I procollagen, although his mother was heterozygous and his father did not have the mutation. Phenotypically, the proband was similar to the two previously reported cases with uniparental disomy for chromosome 7, in that he was short in stature and growth retarded. Paternity was assessed with five polymorphic markers. Chromosome 7 inheritance in the proband was analyzed using 12 polymorphic markers distributed along the entire chromosome. Similar analysis of the proband's two brothers established the phase of the alleles at the various loci, assuming minimal recombination. The proband inherited only maternal alleles at five loci and was homozygous at all loci examined, except one. He was heterozygous for an RFLP at the IGBP-1 locus at 7p13-p12. The results suggest that the isodisomy was not complete because of a recombination event involving the proximal short arms of two maternal chromosomes. In addition, the phenotype of proportional dwarfism in the proband suggests imprinting of one or more growth-related genes on chromosome 7. 42 refs., 5 figs., 3 tabs.

Rejoining of x-ray induced chromosome breaks in human cells and its relationship to cellular repair

International Nuclear Information System (INIS)

Cornforth, M.N.

1985-01-01

A method was developed to improve the resolution for measuring breaks produced in interphase chromosomes by X-rays following the induction of premature chromosome condensation (PCC). It is based on the principle of 5-BrdU incorporation into the DNA of HeLa mitotic cells, which act as inducers of PCC when they are fused to diploid human fibroblasts. After a modified Fluorescence Plus Giemsa (FPG) protocol, the PCC stain intensely, while the mitotic inducer chromosomes stain faintly. The dose response for density inhibited (G 0 ) human cells was linear from 10.9 to 600 rad, with a slope of 0.06 breaks per cell per rad. Upon incubation at 37 0 C, half of the breaks disappeared in 2 hours. Following a dose of 600 rad the initial rate of break rejoining mirrored the rate of increase in survival from post-irradiation incubation, due to the repair of potentially lethal damage (PLD). The X-ray induced PCC rejoining characteristics from two ataxia telangiectasia (A-T) cell lines were compared to profiles obtained with normal cells. Both normal and A-T cells apparently sustained the same initial level of radiation damage, and both cell types rejoined breaks at the same rate. However, while normal cells eventually rejoined all but about 5% of the breaks produced by 600 rad, the A-T lines were left with 5-6 times the level of residual damage. These experiments demonstrate that progression of cells into S phase is not a necessary condition for the measured frequency of chromosome fragments observed in X-irradiated A-T cells

The human thyroglobulin gene: a polymorphic marker localized distal to C-MYC on chromosome 8 band q24

NARCIS (Netherlands)

Baas, F.; Bikker, H.; Geurts van Kessel, A.; Melsert, R.; Pearson, P. L.; de Vijlder, J. J.; van Ommen, G. J.

1985-01-01

The human thyroglobulin (Tg) gene is localized to chromosome 8 and regionally to band q24 as shown independently by both in situ hybridization techniques and Southern blot analysis of human-rodent somatic cell hybrids. Analysis of hybrids derived from a Burkitt lymphoma, with a translocation

Analysis of 62 hybrid assembled human Y chromosomes exposes rapid structural changes and high rates of gene conversion.

Directory of Open Access Journals (Sweden)

Laurits Skov

2017-08-01

Full Text Available The human Y-chromosome does not recombine across its male-specific part and is therefore an excellent marker of human migrations. It also plays an important role in male fertility. However, its evolution is difficult to fully understand because of repetitive sequences, inverted repeats and the potentially large role of gene conversion. Here we perform an evolutionary analysis of 62 Y-chromosomes of Danish descent sequenced using a wide range of library insert sizes and high coverage, thus allowing large regions of these chromosomes to be well assembled. These include 17 father-son pairs, which we use to validate variation calling. Using a recent method that can integrate variants based on both mapping and de novo assembly, we genotype 10898 SNVs and 2903 indels (max length of 27241 bp in our sample and show by father-son concordance and experimental validation that the non-recurrent SNP and indel variation on the Y chromosome tree is called very accurately. This includes variation called in a 0.9 Mb centromeric heterochromatic region, which is by far the most variable in the Y chromosome. Among the variation is also longer sequence-stretches not present in the reference genome but shared with the chimpanzee Y chromosome. We analyzed 2.7 Mb of large inverted repeats (palindromes for variation patterns among the two palindrome arms and identified 603 mutation and 416 gene conversions events. We find clear evidence for GC-biased gene conversion in the palindromes (and a balancing AT mutation bias, but irrespective of this, also a strong bias towards gene conversion towards the ancestral state, suggesting that palindromic gene conversion may alleviate Muller's ratchet. Finally, we also find a large number of large-scale gene duplications and deletions in the palindromic regions (at least 24 and find that such events can consist of complex combinations of simultaneous insertions and deletions of long stretches of the Y chromosome.

Human placental Na+, K+-ATPase α subunit: cDNA cloning, tissue expression, DNA polymorphism, and chromosomal localization

International Nuclear Information System (INIS)

Chehab, F.F.; Kan, Y.W.; Law, M.L.; Hartz, J.; Kao, F.T.; Blostein, R.

1987-01-01

A 2.2-kilobase clone comprising a major portion of the coding sequence of the Na + , K + -ATPase α subunit was cloned from human placenta and its sequence was identical to that encoding the α subunit of human kidney and HeLa cells. Transfer blot analysis of the mRNA products of the Na + , K + -ATPase gene from various human tissues and cell lines revealed only one band (≅ 4.7 kilobases) under low and high stringency washing conditions. The levels of expression in the tissues were intestine > placenta > liver > pancreas, and in the cell lines the levels were human erythroleukemia > butyrate-induced colon > colon > brain > HeLa cells. mRNA was undetectable in reticulocytes, consistent with the authors failure to detect positive clones in a size-selected ( > 2 kilobases) λgt11 reticulocyte cDNA library. DNA analysis revealed by a polymorphic EcoRI band and chromosome localization by flow sorting and in situ hybridization showed that the α subunit is on the short is on the short arm (band p11-p13) of chromosome 1

The Consequences of Chromosome Segregation Errors in Mitosis and Meiosis

Directory of Open Access Journals (Sweden)

Tamara Potapova

2017-02-01

Full Text Available Mistakes during cell division frequently generate changes in chromosome content, producing aneuploid or polyploid progeny cells. Polyploid cells may then undergo abnormal division to generate aneuploid cells. Chromosome segregation errors may also involve fragments of whole chromosomes. A major consequence of segregation defects is change in the relative dosage of products from genes located on the missegregated chromosomes. Abnormal expression of transcriptional regulators can also impact genes on the properly segregated chromosomes. The consequences of these perturbations in gene expression depend on the specific chromosomes affected and on the interplay of the aneuploid phenotype with the environment. Most often, these novel chromosome distributions are detrimental to the health and survival of the organism. However, in a changed environment, alterations in gene copy number may generate a more highly adapted phenotype. Chromosome segregation errors also have important implications in human health. They may promote drug resistance in pathogenic microorganisms. In cancer cells, they are a source for genetic and phenotypic variability that may select for populations with increased malignance and resistance to therapy. Lastly, chromosome segregation errors during gamete formation in meiosis are a primary cause of human birth defects and infertility. This review describes the consequences of mitotic and meiotic errors focusing on novel concepts and human health.

Chromosomal mechanisms in murine radiation acute myeloid leukemogenesis

International Nuclear Information System (INIS)

Bouffler, S.D.; Breckon, G.; Cox, R.

1996-01-01

Chromosome 2 abnormalities, particularly interstitial deletions, characterize murine radiation-induced acute myeloid leukaemias (AMLs). Here, G-band analyses in CBA/H mice of early (1-6 month) post 3 Gy X-radiation events in bone marrow cells in vivo and karyotype evolution in one unusual AML are presented. The early event analysis showed that all irradiated animals carry chromosome 2 abnormalities, that chromosome 2 abnormalities are more frequent than expected and that interstitial deletions are more common in chromosome 2 than in the remainder of the genome. On presentation AML case N122 carried a t(2; 11) terminal translocation which, with passaging, evolved into a del2(C3F3). Therefore two pathways in leukaemogenesis might exist, one deletion-driven, the other terminal tranlocation-driven involving interstitial genes and terminal genes respectively of chromosome 2. As all irradiated individuals carried chromosome 2 abnormalities, the formation of these aberrations does not determine individual leukaemogenic sensitivity as only 20-25% of animals would be expected to develop AML. Similar lines of argument suggest that chromosome 2 abnormalities are necessary but not sufficient for radiation leukaemogenesis in CBA/H nor are they rate limiting in leukaemogenesis. (Author)

Effect of caffeine posttreatment on X-ray-induced chromosomal aberrations in human blood lymphocytes in vitro

Energy Technology Data Exchange (ETDEWEB)

Natarajan, A T [Rijksuniversiteit Leiden (Netherlands). Dept. of Radiation Genetics and Chemical Mutagenesis; Cohen (J.A.) Inst. voor Radiopathologie en Stralenbescherming, Leiden (Netherlands)); Obe, G [Rijksuniversiteit Leiden (Netherlands). Dept. of Radiation Genetics and Chemical Mutagenesis; Cohen (J.A.) Inst. voor Radiopathologie en Stralenbescherming, Leiden (Netherlands); Freie Univ. Berlin (Germany, F.R.). Inst. fuer Genetik); Dulout, F N [Rijksuniversiteit Leiden (Netherlands). Dept. of Radiation Genetics and Chemical Mutagenesis; Instituto Multidisciplinario de Biologia Celular, La Plata (Argentinia))

1980-01-01

The potentiating effect of caffeine on X-ray-induced chromosomal aberrations in human blood lymphocytes has been investigated, with special reference to cell cycle stages (G0 and G2). Both quantitative and qualitative differences in the yield of chromosomal aberrations were detected in caffeine-posttreated cells, depending on the cell stage irradiated. The studies on caffeine potentiating effects on X-irradiated G0 lymphocytes from normal adults, newborns, Down syndrome patients, and an ataxia telangiectasia patient pointed to interindividual variations in the response to caffeine potentiation among normal probands and a very profound effect in ataxia cells.

Symmetrical exchanges between chromosomes induced by irradiation of human lymphocytes with fast neutrons and detected by repeated fluorescence in situ hybridisation

International Nuclear Information System (INIS)

Lukasova, E.; Kozubek, S.; Ryznar, L.; Mareckova, A.; Bartova, E.; Kozubek, M.; Skalnikova, M.; Kroha, V.

1998-01-01

The frequency was studied of exchange aberrations between chromosomes no. 1, 2, 3, 4, 6, 8, 9, 11, 12, 14, 18, and 22 in the first postirradiation mitosis of human lymphocytes irradiated with various doses of neutrons of a mean energy of 7 MeV. Seven repeated hybridizations were carried out. Seven different images were obtained for each mitosis, in which two specific chromosomes were distinguished from the others by red and green fluorescence. The successive images were compared, whereby the frequencies of exchange aberrations between the visualized chromosomes were found. The results show a higher frequency of exchanges between chromosomes 14/8, 14/18, 14/3, 8/3, 8/1, and 8/18. No exchange aberrations occurred between the upper of the chromosomes mentioned and chromosomes 9, 22, 4, or 12. The results suggest that chromosomes 1, 3, 8, 14, and 18 are located in mutual vicinity in the interphase nuclei of lymphocytes. This vicinity seems to be one of the reasons for the spontaneous reciprocal exchanges between chromosome 14 and the remaining chromosomes mentioned (1, 3, 8, 18), characteristic for the malignancy of B-lymphocytes in various types of non-Hodgkin lymphomas

HHV-6A/B Integration and the Pathogenesis Associated with the Reactivation of Chromosomally Integrated HHV-6A/B.

Science.gov (United States)

Collin, Vanessa; Flamand, Louis

2017-06-26

Unlike other human herpesviruses, human herpesvirus 6A and 6B (HHV-6A/B) infection can lead to integration of the viral genome in human chromosomes. When integration occurs in germinal cells, the integrated HHV-6A/B genome can be transmitted to 50% of descendants. Such individuals, carrying one copy of the HHV-6A/B genome in every cell, are referred to as having inherited chromosomally-integrated HHV-6A/B (iciHHV-6) and represent approximately 1% of the world's population. Interestingly, HHV-6A/B integrate their genomes in a specific region of the chromosomes known as telomeres. Telomeres are located at chromosomes' ends and play essential roles in chromosomal stability and the long-term proliferative potential of cells. Considering that the integrated HHV-6A/B genome is mostly intact without any gross rearrangements or deletions, integration is likely used for viral maintenance into host cells. Knowing the roles played by telomeres in cellular homeostasis, viral integration in such structure is not likely to be without consequences. At present, the mechanisms and factors involved in HHV-6A/B integration remain poorly defined. In this review, we detail the potential biological and medical impacts of HHV-6A/B integration as well as the possible chromosomal integration and viral excision processes.

Cancer risk in humans predicted by increased levels of chromosomal aberrations in lymphocytes: Nordic study group on the health risk of chromosome damage

DEFF Research Database (Denmark)

Hagmar, L; Brøgger, A; Hansteen, I L

1994-01-01

Cytogenetic assays in peripheral blood lymphocytes (PBL) have been used extensively to survey the exposure of humans to genotoxic agents. The conceptual basis for this has been the hypothesis that the extent of genetic damage in PBL reflects critical events for carcinogenic processes in target...... tissues. Until now, no follow-up studies have been performed to assess the predictive value of these methods for subsequent cancer risk. In an ongoing Nordic cohort study of cancer incidence, 3182 subjects were examined between 1970 and 1988 for chromosomal aberrations (CA), sister chromatid exchange.......0009) in CA strata with regard to subsequent cancer risk. The point estimates of the standardized incidence ratio in the three CA strata were 0.9, 0.7, and 2.1, respectively. Thus, an increased level of chromosome breakage appears to be a relevant biomarker of future cancer risk....

The effects of exposure to different clastogens on the pattern of chromosomal aberrations detected by FISH whole chromosome painting in occupationally exposed individuals

International Nuclear Information System (INIS)

Beskid, O.; Dusek, Z.; Solansky, I.; Sram, R.J.

2006-01-01

The pattern of chromosomal aberrations (CA) was studied by fluorescence in situ hybridization (FISH) technique (whole chromosomes 1 and 4 painting) in workers occupationally exposed to any of the four following conditions: acrylonitrile (ACN), ethyl benzene (EB), carcinogenic polycyclic aromatic hydrocarbons (c-PAHs), and irradiation in nuclear power plants (NPP), respectively. Decrease in the relative frequency of translocations was observed in EB group, and an increase in reciprocal translocations in ACN and NPP-exposed groups. An increase in a relative number of insertions was registered under all four conditions (significant at ACN, EB, c-PAHs, quasisignificant at NPP-exposed groups). Significant differences in the percentage of lymphocytes with aberrations on chromosome 1 (58.8 ± 32.7%, versus 73.8 ± 33.6% in the controls, P G /100) increased with age (P G /100 (P < 0.05), but did not affect the pattern of chromosomal aberrations. Our results seem to indicate that different carcinogens may induce a different pattern of chromosomal aberrations

Determination of hidden chromosome instability in persons suffered from the action of factors of the Chernobyl accident by the modified 'G2 bleomycin sensitivity assay'

International Nuclear Information System (INIS)

Dibs'kij, S.S.; Dibs'ka, O.B.; Pedan, L.P.; Pyilyins'ka, M.A.

2009-01-01

With the help of the modified 'G 2 -bleomycin sensitivity assay' the voluntary investigation of hidden chromosome instability in 53 persons with different radiation exposures had been fulfilled. In all examined groups, the individual levels of chromosome injuries under identical bleomycin exposure varied in a wide range and didn't depend on their initial values in intact cultures. Among control donors and individuals with low radiation exposure, ∼ 33 % hypertensive persons had been identified that can be considered as a genetically caused phenomenon. In patients recovered from acute radiation, 57.9 % persons expressed the hidden chromosome instability. The data obtained allow us to assume that high doses of ionizing radiation can modify the inherited susceptibility of human chromosomes to a mutagen exposure.

Transmission of clonal chromosomal abnormalities in human hematopoietic stem and progenitor cells surviving radiation exposure

Energy Technology Data Exchange (ETDEWEB)

Kraft, Daniela, E-mail: d.kraft@gsi.de [GSI Helmholtz Center for Heavy Ion Research, Department of Biophysics, Planckstr. 1, 64291 Darmstadt (Germany); Institute for Transfusion Medicine und Immunohematology, DRK-Blutspendedienst Baden-Wuerttemberg—Hessen, Johann Wolfgang Goethe-University Hospital, Sandhofstrasse 1, 60528 Frankfurt (Germany); Ritter, Sylvia, E-mail: s.ritter@gsi.de [GSI Helmholtz Center for Heavy Ion Research, Department of Biophysics, Planckstr. 1, 64291 Darmstadt (Germany); Durante, Marco, E-mail: m.durante@gsi.de [GSI Helmholtz Center for Heavy Ion Research, Department of Biophysics, Planckstr. 1, 64291 Darmstadt (Germany); Institute for Condensed Matter Physics, Physics Department, Technical University Darmstadt, Hochschulstraße 6-8, 64289 Darmstadt (Germany); Seifried, Erhard, E-mail: e.seifried@blutspende.de [Institute for Transfusion Medicine und Immunohematology, DRK-Blutspendedienst Baden-Wuerttemberg—Hessen, Johann Wolfgang Goethe-University Hospital, Sandhofstrasse 1, 60528 Frankfurt (Germany); Fournier, Claudia, E-mail: c.fournier@gsi.de [GSI Helmholtz Center for Heavy Ion Research, Department of Biophysics, Planckstr. 1, 64291 Darmstadt (Germany); Tonn, Torsten, E-mail: t.tonn@blutspende.de [Institute for Transfusion Medicine und Immunohematology, DRK-Blutspendedienst Baden-Wuerttemberg—Hessen, Johann Wolfgang Goethe-University Hospital, Sandhofstrasse 1, 60528 Frankfurt (Germany); Technische Universität Dresden, Med. Fakultät Carl Gustav Carus, Institute for Transfusion Medicine Dresden, German Red Cross Blood Donation Service North-East, Blasewitzer Straße 68/70, 01307 Dresden (Germany)

2015-07-15

Highlights: • Radiation induced formation and transmission of chromosomal aberrations were assessed. • Cytogenetic analysis was performed in human CD34+ HSPC by mFISH. • We report transmission of stable aberrations in irradiated, clonally expanded HSPC. • Unstable aberrations in clonally expanded HSPC occur independently of irradiation. • Carbon ions and X-rays bear a similar risk for propagation of cytogenetic changes. - Abstract: In radiation-induced acute myeloid leukemia (rAML), clonal chromosomal abnormalities are often observed in bone marrow cells of patients, suggesting that their formation is crucial in the development of the disease. Since rAML is considered to originate from hematopoietic stem and progenitor cells (HSPC), we investigated the frequency and spectrum of radiation-induced chromosomal abnormalities in human CD34{sup +} cells. We then measured stable chromosomal abnormalities, a possible biomarker of leukemia risk, in clonally expanded cell populations which were grown for 14 days in a 3D-matrix (CFU-assay). We compared two radiation qualities used in radiotherapy, sparsely ionizing X-rays and densely ionizing carbon ions (29 and 60–85 keV/μm, doses between 0.5 and 4 Gy). Only a negligible number of de novo arising, unstable aberrations (≤0.05 aberrations/cell, 97% breaks) were measured in the descendants of irradiated HSPC. However, stable aberrations were detected in colonies formed by irradiated HSPC. All cells of the affected colonies exhibited one or more identical aberrations, indicating their clonal origin. The majority of the clonal rearrangements (92%) were simple exchanges such as translocations (77%) and pericentric inversions (15%), which are known to contribute to the development of rAML. Carbon ions were more efficient in inducing cell killing (maximum of ∼30–35% apoptotic cells for 2 Gy carbon ions compared to ∼25% for X-rays) and chromosomal aberrations in the first cell-cycle after exposure (∼70% and �

Chromosomally Integrated Human Herpesvirus 6: Models of Viral Genome Release from the Telomere and Impacts on Human Health.

Science.gov (United States)

Wood, Michael L; Royle, Nicola J

2017-07-12

Human herpesvirus 6A and 6B, alongside some other herpesviruses, have the striking capacity to integrate into telomeres, the terminal repeated regions of chromosomes. The chromosomally integrated forms, ciHHV-6A and ciHHV-6B, are proposed to be a state of latency and it has been shown that they can both be inherited if integration occurs in the germ line. The first step in full viral reactivation must be the release of the integrated viral genome from the telomere and here we propose various models of this release involving transcription of the viral genome, replication fork collapse, and t-circle mediated release. In this review, we also discuss the relationship between ciHHV-6 and the telomere carrying the insertion, particularly how the presence and subsequent partial or complete release of the ciHHV-6 genome may affect telomere dynamics and the risk of disease.

Prediction for the occurrence of clonal chromosome aberrations in human blood lymphocytes

International Nuclear Information System (INIS)

Nakano, M.; Kadama, Y.; Ohtaki, K.; Itoh, M.; Awa, A.; Cologne, J.; Nakamura, N.

2003-01-01

Full text: Identical chromosome aberrations among multiple blood lymphocytes in a blood sample (clonal aberrations) are encountered occasionally during cytogenetic examination of radiation-exposed people. Clonal aberrations are found primarily among high-dose exposed people but no systematic surveys were ever conducted. Therefore, the underlying mechanism is unknown. Here we conducted a large-scale screening for detecting clonal aberrations using FISH followed by Q-banding. Examinations of 500 cells from each of 513 A-bomb survivors led us to detect 96 clones. The clonal cell fraction (Cf) varied from 0.6% to 20% among the 500 cells. As the number of clonal event was inversely proportional to Cf, we hypothesized that the progenitor cells vary extensively in the number of offspring that they can produce and relative number of progenitor cells decreases as the increase of treatment, while other genes such as DNA repair proteinsnumber of progenitor cells capable to form clones (Cf >=0.6%) to be 2 (1 to 3) in non-exposed individuals. The number increased to up to 7 among the high-dose exposed survivors. Further, our preliminary results for the origins of 10 clones indicated that both hematopoietic stem cells (HSCs) and mature T cells contributed to the clone formation roughly equally. Thus, the estimated number of 2 in non-exposed individuals is shared as one HSC and one mature T cells. The model could neatly explain the frequency of clones in two reports. Our model predicts that clonal aberrations are rarely found but clonal expansion of T lymphocytes occurs commonly. In fact, clonal expansions of non-aberrant cells are reported using TCR gene rearrangement patterns as a marker. We now understand the rough structure of lymphocyte pool in humans and can predict the probability of detecting a clone if the individual frequency of non-clonal translocations and the number of cells scored are given

Chromosomal aberrations induced by alpha particles

International Nuclear Information System (INIS)

Guerrero C, C.; Brena V, M.

2005-01-01

The chromosomal aberrations produced by the ionizing radiation are commonly used when it is necessary to establish the exposure dose of an individual, it is a study that is used like complement of the traditional physical systems and its application is only in cases in that there is doubt about what indicates the conventional dosimetry. The biological dosimetry is based on the frequency of aberrations in the chromosomes of the lymphocytes of the individual in study and the dose is calculated taking like reference to the dose-response curves previously generated In vitro. A case of apparent over-exposure to alpha particles to which is practiced analysis of chromosomal aberrations to settle down if in fact there was exposure and as much as possible, to determine the presumed dose is presented. (Author)

Dose response curve for prematurely condensed chromosome fragments of human lymphocytes after 60Co-γ ray exposure

International Nuclear Information System (INIS)

Gao Jinsheng; Zheng Siying; Bao Hong

1992-06-01

The dose-effect relationship of premature condensed chromosome fragments in human lymphocytes irradiated by 60 Co gamma ray was studied by PCC method (premature condensed chromosomes). In addition, The conventional cellular genetics method was also used in the study. The response curve of both methods can represented by two linear equations. The ratio of two slopes, K PCC /K M1 , is about 28. Comparing with conventional method, the PCC method has many advantages such as faster, simpler, more sensitive and accurate. The PCC method used in the studying of radiation damage is also discussed

Caffeine potentiates or protects against radiation-induced DNA and chromosomal damage in human lymphocytes depending on temperature and concentration

International Nuclear Information System (INIS)

Stoilov, L.M.; Mullenders, L.H.F.; Natarajan, A.T.

1994-01-01

The effect of caffeine on radiation-induced chromosomal aberrations and DNA strand breaks in unstimulated human lymphocytes was investigated. When present prior to and during the radiation exposure, caffeine treatment was found to cause either potentiation or protection against induction of chromosomal aberrations depending on the concentration and temperature. When the nucleoid sedimentation technique was applied, enhancement or reduction of radiation-induced DNA strand breaks by caffeine was also found to be dependent on temperature and caffeine concentration. It is proposed that caffeine, in addition to its suspected ability to influence DNA repair, can also influence the induction of DNA damage, leading to alterations in the yield of chromosomal aberrations

Caffeine potentiates or protects against radiation-induced DNA and chromosomal damage in human lymphocytes depending on temperature and concentration

Energy Technology Data Exchange (ETDEWEB)

Stoilov, L.M. (Department of Molecular Genetics, Institute of Genetics, Sofia (Bulgaria)); Mullenders, L.H.F.; Natarajan, A.T. (J.A. Cohen Institute, Interuniversity Research Institute for Radiopathology and Radiation Protection, Leiden (Netherlands))

1994-12-01

The effect of caffeine on radiation-induced chromosomal aberrations and DNA strand breaks in unstimulated human lymphocytes was investigated. When present prior to and during the radiation exposure, caffeine treatment was found to cause either potentiation or protection against induction of chromosomal aberrations depending on the concentration and temperature. When the nucleoid sedimentation technique was applied, enhancement or reduction of radiation-induced DNA strand breaks by caffeine was also found to be dependent on temperature and caffeine concentration. It is proposed that caffeine, in addition to its suspected ability to influence DNA repair, can also influence the induction of DNA damage, leading to alterations in the yield of chromosomal aberrations.

Satellite DNA-based artificial chromosomes for use in gene therapy.

Science.gov (United States)

Hadlaczky, G

2001-04-01

Satellite DNA-based artificial chromosomes (SATACs) can be made by induced de novo chromosome formation in cells of different mammalian species. These artificially generated accessory chromosomes are composed of predictable DNA sequences and they contain defined genetic information. Prototype human SATACs have been successfully constructed in different cell types from 'neutral' endogenous DNA sequences from the short arm of the human chromosome 15. SATACs have already passed a number of hurdles crucial to their further development as gene therapy vectors, including: large-scale purification; transfer of purified artificial chromosomes into different cells and embryos; generation of transgenic animals and germline transmission with purified SATACs; and the tissue-specific expression of a therapeutic gene from an artificial chromosome in the milk of transgenic animals.

Chromosome Banding in Amphibia. XXXVI. Multimorphic Sex Chromosomes and an Enigmatic Sex Determination in Eleutherodactylus johnstonei (Anura, Eleutherodactylidae).

Science.gov (United States)

Schmid, Michael; Steinlein, Claus

2018-01-01

A detailed cytogenetic study on the leaf litter frog Eleutherodactylus johnstonei from 14 different Caribbean islands and the mainlands of Venezuela and Guyana revealed the existence of multimorphic XY♂/XX♀ sex chromosomes 14. Their male sex determination and development depends either on the presence of 2 telocentric chromosomes 14 (XtYt), or on 1 submetacentric chromosome 14 (Xsm) plus 1 telocentric chromosome 14 (Yt), or on the presence of 2 submetacentric chromosomes 14 (XsmYsm). The female sex determination and development requires either the presence of 2 telocentric chromosomes 14 (XtXt) or 2 submetacentric chromosomes 14 (XsmXsm). In all individuals analyzed, the sex chromosomes 14 carry a prominent nucleolus organizer region in their long arms. An explanation is given for the origin of the (XtYt)♂, (XsmYt)♂, (XsmYsm)♂, (XtXt)♀, and (XsmXsm)♀ in the different populations of E. johnstonei. Furthermore, the present study gives detailed data on the chromosome banding patterns, in situ hybridization experiments, and the genome size of E. johnstonei. © 2018 S. Karger AG, Basel.

Chromosomal clustering of a human transcriptome reveals regulatory background

Directory of Open Access Journals (Sweden)

Purmann Antje

2005-09-01

Full Text Available Abstract Background There has been much evidence recently for a link between transcriptional regulation and chromosomal gene order, but the relationship between genomic organization, regulation and gene function in higher eukaryotes remains to be precisely defined. Results Here, we present evidence for organization of a large proportion of a human transcriptome into gene clusters throughout the genome, which are partly regulated by the same transcription factors, share biological functions and are characterized by non-housekeeping genes. This analysis was based on the cardiac transcriptome identified by our genome-wide array analysis of 55 human heart samples. We found 37% of these genes to be arranged mainly in adjacent pairs or triplets. A significant number of pairs of adjacent genes are putatively regulated by common transcription factors (p = 0.02. Furthermore, these gene pairs share a significant number of GO functional classification terms. We show that the human cardiac transcriptome is organized into many small clusters across the whole genome, rather than being concentrated in a few larger clusters. Conclusion Our findings suggest that genes expressed in concert are organized in a linear arrangement for coordinated regulation. Determining the relationship between gene arrangement, regulation and nuclear organization as well as gene function will have broad biological implications.

Chromosomal geometry in the interface from the frequency of the radiation induced chromosome aberrations

International Nuclear Information System (INIS)

Nasazzi, N.; Otero, D.; Di Giorgio, M.

1996-01-01

Ionizing radiation induces DNA double-strand breaks (DSBs) and their interaction and illegitimate recombination produces chromosomal aberrations. Stable chromosomal aberrations comprise inter-chromosomal events (translocations) and intra-chromosomal events (inversions). When DSBs induction and interaction is done at random, and the proximity effects are neglected, the expected relation between translocations and inversions is F=86, based on chromosome arm length. The number of translocations and inversions is analyzed by using G-banding in 16 lymphocytes cultures from blood samples acutely irradiated with γ-rays (dose range: 0,5 Gy - 3 Gy). The result obtained was: F=13,5, significantly smaller than F=86. Literature data show similar small F values, but strongly spread. The excess of inversions could be explained by a 'proximity effect', it means that more proximate DSBs have more interaction probability. Therefore, it is possible to postulate a special chromosome arrangement during irradiation and the subsequent interval. We propose a model where individual chromosomes show spherical confinement with some degree of overlapping and DSBs induction proportional to cross section. A DSBs interaction probability function with cut-off length= 1μ is assumed. According to our results, the confinement volume is ≅ 6.4% of the nuclear volume. Nevertheless, we presume that large spread in F data could be due to temporal variation in overlapping and spatial chromosomal confinement. (authors). 14 refs

Chromosomes, cancer and radiosensitivity

International Nuclear Information System (INIS)

Samouhos, E.

1983-01-01

Some specific chromosomal abnormalities are associated with certain cancers. The earliest description of such a specific association is the one of the Philadelphia chromosome and myelogenous leukemia (1960). Other congenital karyotype abnormalities are associated with specific cancers. Examples of these are Down's syndrome with leukemia and Klinefelter's syndrome with male breast cancer. Genetic diseases of increased chromosome breakage, or of defective chromosome repair, are associated with greatly increased cancer incidence. Three such diseases have been recognized: 1) Fanconi's anemia, associated with leukemias and lymphomas, 2) Bloom's syndrome, associated with acute leukemias and lymphosarcoma, and 3) ataxia telangiectasia, associated with Hodgkin's disease, leukemia, and lymphosarcomas. Ten percent of individuals with ataxia telangiectasia will develop one of these neoplasms. Individuals with certain of these syndromes display an unusually high radiosensitivity. Radiation therapy for cancers has been fatal in patients who received as low as 3000 rad. This remarkable radiosensitivity has been quantitated in cell cultures from such cases. Evidence suggests that the apparent sensitivity may reflect subnormal ability to repair radiation damage. The rapid proliferation of information in this field stems from the interdigitation of many disciplines and specialties, including cytogenetics, cell biology, molecular biology, epidemiology, radiobiology, and several others. This paper is intended for clinicians; it presents a structured analytic scheme for correlating and classifying this multidisciplinary information as it becomes available

Induction of anchorage-independent growth of human embryonic fibroblasts with a deletion in the short arm of chromosome 11 by human papillomavirus type 16 DNA

International Nuclear Information System (INIS)

Smits, H.L.; Raadsheer, E.; Rood, I.; Mehendale, S.; Slater, R.M.; van der Noordaa, J.; Ter Schegget, J.

1988-01-01

Human embryonic fibroblasts with a large deletion (11p11.11p15.1) in the short arm of one chromosome 11 (del-11 cells) appeared to be susceptible to transformation by early human papillomavirus type 16 (HPV-16) DNA, whereas diploid human embryonic fibroblasts were not. This difference in susceptibility might be explained by the absence of a tumor suppressor gene located within the deleted part on the short arm of chromosome 11. The presence of abundant viral early-gene transcripts in transformed cells suggests that transformation was induced by an elevated level of an HPV-16 early-gene product(s). The low transcriptional activity of HPV-16 in diploid cells may indicate that cellular genes affect viral transcription. Interruption of the HPV-16 E2 early open reading frame is probably required for high-level HPV-16 early-gene expression driven from the homologous enhancer-promoter region

Delayed cell death, giant cell formation and chromosome instability induced by X-irradiation in human embryo cells

International Nuclear Information System (INIS)

Roy, K.; Kodama, Seiji; Suzuki, Keiji; Watanabe, Masami

1999-01-01

We studied X-ray-induced delayed cell death, delayed giant cell formation and delayed chromosome aberrations in normal human embryo cells to explore the relationship between initial radiation damage and delayed effect appeared at 14 to 55 population doubling numbers (PDNs) after X-irradiation. The delayed effect was induced in the progeny of X-ray survivors in a dose-dependent manner and recovered with increasing PDNs after X-irradiation. Delayed plating for 24 h post-irradiation reduced both acute and delayed lethal damage, suggesting that potentially lethal damage repair (PLDR) can be effective for relieving the delayed cell death. The chromosome analysis revealed that most of the dicentrics (more than 90%) observed in the progeny of X-ray survivors were not accompanied with fragments, in contrast with those observed in the first mitosis after X-irradiation. The present results indicate that the potentiality of genetic instability is determined during the repair process of initial radiation damage and suggest that the mechanism for formation of delayed chromosome aberrations by radiation might be different from that of direct radiation-induced chromosome aberrations. (author)

High-resolution whole-genome sequencing reveals that specific chromatin domains from most human chromosomes associate with nucleoli.

Science.gov (United States)

van Koningsbruggen, Silvana; Gierlinski, Marek; Schofield, Pietá; Martin, David; Barton, Geoffey J; Ariyurek, Yavuz; den Dunnen, Johan T; Lamond, Angus I

2010-11-01

The nuclear space is mostly occupied by chromosome territories and nuclear bodies. Although this organization of chromosomes affects gene function, relatively little is known about the role of nuclear bodies in the organization of chromosomal regions. The nucleolus is the best-studied subnuclear structure and forms around the rRNA repeat gene clusters on the acrocentric chromosomes. In addition to rDNA, other chromatin sequences also surround the nucleolar surface and may even loop into the nucleolus. These additional nucleolar-associated domains (NADs) have not been well characterized. We present here a whole-genome, high-resolution analysis of chromatin endogenously associated with nucleoli. We have used a combination of three complementary approaches, namely fluorescence comparative genome hybridization, high-throughput deep DNA sequencing and photoactivation combined with time-lapse fluorescence microscopy. The data show that specific sequences from most human chromosomes, in addition to the rDNA repeat units, associate with nucleoli in a reproducible and heritable manner. NADs have in common a high density of AT-rich sequence elements, low gene density and a statistically significant enrichment in transcriptionally repressed genes. Unexpectedly, both the direct DNA sequencing and fluorescence photoactivation data show that certain chromatin loci can specifically associate with either the nucleolus, or the nuclear envelope.

Non-disjunction of chromosome 13

DEFF Research Database (Denmark)

Bugge, Merete; Collins, Andrew; Hertz, Jens Michael

2007-01-01

We performed a molecular study with 21 microsatellites on a sample of 82 trisomy 13 conceptuses, the largest number of cases studied to date. The parental origin was determined in every case and in 89% the extra chromosome 13 was of maternal origin with an almost equal number of maternal MI and MII...... recombination in both maternal MI and MII errors and the former is associated with a significant number of tetrads (33%) that are nullichiasmate, which do not appear to be a feature of normal chromosome 13 meiosis. This study supports the evidence for subtle chromosome-specific influences on the mechanisms...... that determine non-disjunction of human chromosomes, consistent with the diversity of findings for other trisomies. Udgivelsesdato: 2007-Aug-15...

Use of FISH-translocations analyses for retrospective biological dosimetry: How stable are stable chromosome aberrations?

International Nuclear Information System (INIS)

Darroudi, F.

2000-01-01

Chromosome aberrations, in particular dicentrics, in peripheral blood lymphocytes are used to estimate the absorbed dose immediately following a radiation accident. However, difficulties for dose estimation arise with old exposures, due to a decline of cells containing unstable dicentric aberrations. The fluorescence in situ hybridisation (FISH) technique employing chromosome specific DNA libraries to 'paint' individual human chromosomes has opened new perspectives for rapid and reliable detection of stable chromosome aberrations such as translocations. The inherent stability of translocations over cell generations has enabled them to be used as a biodosemeter. However, due to the limited life of circulating T-lymphocytes, a level of uncertainty exists on the long-term persistence of stable translocations. The objectives of the present work are to present the current state of knowledge on the stability of translocations detected by FISH. The following aspects have been considered; (1) experience so far of retrospective biological dosimetry in humans following accidental and occupational over-exposure, (2) animal studies using mice and monkeys, (3) the influence of subsequent cell divisions on the yield and persistence of translocations following in vitro irradiation of human lymphocytes, and (4) the needs for further work to standardise and validate the use of FISH as a biological dosemeter, and to investigate the influence of various parameters such as radiation quality, dose rate and the discrimination of sub-types of translocations on persistence. (author)

Structure and chromosomal localization of the human renal kallikrein gene

International Nuclear Information System (INIS)

Evans, B.A.; Yun, Z.X.; Close, J.A.

1988-01-01

Glandular kallikreins are a family of proteases encoded by a variable number of genes in different mammalian species. In all species examined, however, one particular kallikrein is functionally conserved in its capacity to release the vasoactive peptide, Lys-bradykinin, from low molecular weight kininogen. This kallikrein is found in the kidney, pancreas, and salivary gland, showing a unique pattern of tissue-specific expression relative to other members of the family. The authors have isolated a genomic clone carrying the human renal kallikrein gene and compared the nucleotide sequence of its promoter region with those of the mouse renal kallikrein gene and another mouse kallikrein gene expressed in a distinct cell type. They find four sequence elements conserved between renal kallikrein genes from the two species. They have also shown that the human gene is localized to 19q13, a position analogous to that of the kallikrein gene family on mouse chromosome 7

Chromosomal disorders and male infertility

Institute of Scientific and Technical Information of China (English)

Gary L Harton; Helen G Tempest

2012-01-01

infertility in humans is surprisingly common occurring in approximately 15％ of the population wishing to start a family.Despite this,the molecular and genetic factors underlying the cause of infertility remain largely undiscovered.Nevertheless,more and more genetic factors associated with infertility are being identified.This review will focus on our current understanding of the chromosomal basis of male infertility specifically:chromosomal aneuploidy,structural and numerical karyotype abnormalities and Y chromosomal microdeletions.Chromosomal aneuploidy is the leading cause of pregnancy loss and developmental disabilities in humans.Aneuploidy is predominantly maternal in origin,but concerns have been raised regarding the safety of intracytoplasmic sperm injection as infertile men have significantly higher levels of sperm aneuploidy compared to their fertile counterparts.Males with numerical or structural karyotype abnormalities are also at an increased risk of producing aneuploid sperm.Our current understanding of how sperm aneuploidy translates to embryo aneuploidy will be reviewed,as well as the application of preimplantation genetic diagnosis (PGD) in such cases.Clinical recommendations where possible will be made,as well as discussion of the use of emerging array technology in PGD and its potential applications in male infertility.

The alpha-spectrin gene is on chromosome 1 in mouse and man.

Science.gov (United States)

Huebner, K; Palumbo, A P; Isobe, M; Kozak, C A; Monaco, S; Rovera, G; Croce, C M; Curtis, P J

1985-06-01

By using alpha-spectrin cDNA clones of murine and human origin and somatic cell hybrids segregating either mouse or human chromosomes, the gene for alpha-spectrin has been mapped to chromosome 1 in both species. This assignment of the mouse alpha-spectrin gene to mouse chromosome 1 by DNA hybridization strengthens the previous identification of the alpha-spectrin locus in mouse with the sph locus, which previously was mapped by linkage analysis to mouse chromosome 1, distal to the Pep-3 locus. By in situ hybridization to human metaphase chromosomes, the human alpha-spectrin gene has been localized to 1q22-1q25; interestingly, the locus for a non-Rh-linked form of elliptocytosis has been provisionally mapped to band 1q2 by family linkage studies.

Styl RFLP recognized by a human IRBP cDNA localized to chromosome 10

Energy Technology Data Exchange (ETDEWEB)

Chin, K S; Mathew, C G.P.; Fong, S L; Bridges, C D; Ponder, B A.J.

1988-02-25

A 2184 bp cDNA (H.4 IRBP) encoding human interstitial retinol-biding protein isolated from a human retina cDNA library in lambdagt10 by screening with a bovine IRBP cDNA probe. Styl identifies a 2-allele polymorphism with bands at 2.3 kb (Cl) and 1.95 kb (C2) and invariant bands at 1.1, 1.0 and 0.8kb. Codominant segregation was observed in two informative families. The RFLP was mapped to chromosome 10 using somatic cell hybrids. In situ hybridization suggests regional assignments near p11.2 -q11.2 with a secondary site of hybridization at q24-25.

Cloning, expression, and chromosome mapping of human galectin-7

DEFF Research Database (Denmark)

Madsen, Peder; Rasmussen, H H; Flint, T

1995-01-01

The galectins are a family of beta-galactoside-binding proteins implicated in modulating cell-cell and cell-matrix interactions. Here we report the cloning and expression of a novel member of this family (galectin-7) that correspond to IEF (isoelectric focusing) 17 (12,700 Da; pI, 7.6) in the human...... keratinocyte protein data base, and that is strikingly down-regulated in SV40 transformed keratinocytes (K14). The cDNA was cloned from a lambda gt11 cDNA expression library using degenerated oligodeoxyribonucleotides back-translated from an IEF 17 peptide sequence. The protein encoded by the galectin-7 clone......14 keratinocytes imply a role in cell-cell and/or cell-matrix interactions necessary for normal growth control. The galectin-7 gene was mapped to chromosome 19. Udgivelsesdato: 1995-Mar-17...

Chromosome 11-linked determinant controls fetal globin expression and the fetal-to-adult globin switch

International Nuclear Information System (INIS)

Melis, M.; Demopulos, G.; Najfeld, V.; Zhang, J.W.; Brice, M.; Papayannopoulou, T.; Stamatoyannopoulos, G.

1987-01-01

Hybrids formed by fusing mouse erythroleukemia (MEL) cells with human fetal erythroid cells produce human fetal globin, but they switch to adult globin production as culture time advances. To obtain information on the chromosomal assignment of the elements that control γ-to-β switching, the authors analyzed the chromosomal composition of hybrids producing exclusively or predominantly human fetal globin and hybrids producing only adult human globin. No human chromosome was consistently present in hybrids expressing fetal globin and consistently absent in hybrids expressing adult globin. Subcloning experiments demonstrated identical chromosomal compositions in subclones displaying the fetal globin program and those that had switched to expression of the adult globin program. These data indicate that retention of only one human chromosome -- i.e., chromosome 11 -- is sufficient for expression of human fetal globin and the subsequent γ-to-β switch. The results suggest that the γ-to-β switch is controlled either cis to the β-globin locus of by a trans-acting mechanism, the genes of which reside on human chromosome 11

Chromosome Aberrations in Human Lymphocytes Irradiated with Ionizing Radiation

Energy Technology Data Exchange (ETDEWEB)

Ryu, Tae Ho; Kim, Jin Hong; Kim, Jin Kyu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2014-05-15

The purpose of the present experiment was to provide data on the dose-dependent production of chromosome aberrations such as dicentrics, centric rings, and excess acentrics. Radiation is one of the more dangerous clastogens in the environment. Ionizing radiation causes chromosome breakages and various cytogenetic aberrations in exposed cells. In an investigation into radiation emergencies, it is important to estimate the dose to exposed persons for several reasons. Physical dosimeters (e. g., film badges) may misrepresent the actual radiation dose and may not be available in a radiological accident or terrorism incident. Biological dosimetry is suitable for estimating the radiation dose during such accidents. The dicentric chromosome assay is very sensitive and a reliable bio-indicator in cases of accidental overexposure.

Chromosomal organization of adrenergic receptor genes

International Nuclear Information System (INIS)

Yang-Feng, T.L.; Xue, Feiyu; Zhong, Wuwei; Cotecchia, S.; Frielle, T.; Caron, M.G.; Lefkowitz, R.J.; Francke, U.

1990-01-01

The adrenergic receptors (ARs) (subtypes α 1 , α 2 , β 1 , and β 2 ) are a prototypic family of guanine nucleotide binding regulatory protein-coupled receptors that mediate the physiological effects of the hormone epinephrine and the neurotransmitter norepinephrine. The authors have previously assigned the genes for β 2 -and α 2 -AR to human chromosomes 5 and 10, respectively. By Southern analysis of somatic cell hybrids and in situ chromosomal hybridization, they have now mapped the α 1 -AR gene to chromosome 5q32→q34, the same position as β 2 -AR, and the β 1 -AR gene to chromosome 10q24→q26, the region where α 2 -AR, is located. In mouse, both α 2 -and β 1 -AR genes were assigned to chromosome 19, and the α 1 -AR locus was localized to chromosome 11. Pulsed field gel electrophoresis has shown that the α 1 -and β 2 -AR genes in humans are within 300 kilobases (kb) and the distance between the α 2 - and β 1 -AR genes is <225 kb. The proximity of these two pairs of AR genes and the sequence similarity that exists among all the ARs strongly suggest that they are evolutionarily related. Moreover, they likely arose from a common ancestral receptor gene and subsequently diverged through gene duplication and chromosomal duplication to perform their distinctive roles in mediation the physiological effects of catecholamines. The AR genes thus provide a paradigm for understanding the evolution of such structurally conserved yet functionally divergent families off receptor molecules

Chromosomes as well as chromosomal subdomains constitute distinct units in interphase nuclei

NARCIS (Netherlands)

Visser, A. E.; Aten, J. A.

1999-01-01

Fluorescence in situ hybridization has demonstrated that chromosomes form individual territories in interphase nuclei. However, this technique is not suitable to determine whether territories are mutually exclusive or interwoven. This notion, however, is essential for understanding functional

Rise, fall and resurrection of chromosome territories: a historical perspective. Part I. The rise of chromosome territories

Directory of Open Access Journals (Sweden)

T Cremer

2009-06-01

Full Text Available It is now generally accepted that chromosomes in the cell nucleus are organized in distinct domains, first called chromosome territories in 1909 by the great cytologist Theodor Boveri. Yet, even today chromosomes have remained enigmatic individuals, whose structures, arrangements and functions in cycling and post-mitotic cells still need to be explored in full detail. Whereas numerous recent reviews describe present evidence for a dynamic architecture of chromosome territories and discuss the potential significance within the functional compartmentalization of the nucleus, a comprehensive historical account of this important concept of nuclear organization was lacking so far. Here, we describe the early rise of chromosome territories within the context of the discovery of chromosomes and their fundamental role in heredity, covering a period from the 1870th to the early 20th century (part I, this volume. In part II (next volume we review the abandonment of the chromosome territory concept during the 1950th to 1980th and the compelling evidence, which led to its resurrection during the 1970th to 1980th.

Comparative Chromosome Map and Heterochromatin Features of the Gray Whale Karyotype (Cetacea).

Science.gov (United States)

Kulemzina, Anastasia I; Proskuryakova, Anastasia A; Beklemisheva, Violetta R; Lemskaya, Natalia A; Perelman, Polina L; Graphodatsky, Alexander S

2016-01-01

Cetacean karyotypes possess exceptionally stable diploid numbers and highly conserved chromosomes. To date, only toothed whales (Odontoceti) have been analyzed by comparative chromosome painting. Here, we studied the karyotype of a representative of baleen whales, the gray whale (Eschrichtius robustus, Mysticeti), by Zoo-FISH with dromedary camel and human chromosome-specific probes. We confirmed a high degree of karyotype conservation and found an identical order of syntenic segments in both branches of cetaceans. Yet, whale chromosomes harbor variable heterochromatic regions constituting up to a third of the genome due to the presence of several types of repeats. To investigate the cause of this variability, several classes of repeated DNA sequences were mapped onto chromosomes of whale species from both Mysticeti and Odontoceti. We uncovered extensive intrapopulation variability in the size of heterochromatic blocks present in homologous chromosomes among 3 individuals of the gray whale by 2-step differential chromosome staining. We show that some of the heteromorphisms observed in the gray whale karyotype are due to distinct amplification of a complex of common cetacean repeat and heavy satellite repeat on homologous autosomes. Furthermore, we demonstrate localization of the telomeric repeat in the heterochromatin of both gray and pilot whale (Globicephala melas, Odontoceti). Heterochromatic blocks in the pilot whale represent a composite of telomeric and common repeats, while heavy satellite repeat is lacking in the toothed whale consistent with previous studies. © 2016 S. Karger AG, Basel.

Assignment of FUT8 to chicken chromosome band 5q1.4 and to human chromosome 14q23.2-->q24.1 by in situ hybridization. Conserved and compared synteny between human and chicken

NARCIS (Netherlands)

Coullin, Ph.; Crooijmans, R.P.M.A.; Groenen, M.A.M.; Heilig, R.; Mollicone, R.; Oriol, R.; Candelier, J.J.

2002-01-01

The human FUT8 gene is implicated in crucial developmental stages and is overexpressed in some tumors and other malignant diseases. Based on three different experiments we have assigned the FUT8 gene to chromosome bands 14q23.2 --> q24.1 and not 14q24.3 as previously shown (Yamaguchi et al.,

The fate of chromosomal aberrations in 137Cs-exposed individuals in the Goiania radiation accident

International Nuclear Information System (INIS)

Ramalho, A.T.; Nascimento, A.C.

1991-01-01

Following the Goiania radiation accident, lymphocytes from 110 exposed or potentially exposed individuals were analyzed for the frequencies of chromosomal aberrations (dicentrics and centric rings) to estimate absorbed radiation dose. Dose estimates for 21 subjects exceeded 1.0 Gy, and for eight subjects they exceeded 4.0 Gy. Four of the subjects died. After the emergency period, a cytogenetic follow-up of 10 of the highest exposed patients was started. The results suggest that the average disappearance half-time of lymphocytes containing dicentric and centric rings was 130 d, which is shorter than the usually accepted value of 3 y reported in the literature

Development of a biological dosimeter for translocation scoring based on two-color fluorescence in situ hybridization of chromosome subsets

Energy Technology Data Exchange (ETDEWEB)

Popp, S; Cremer, T [Heidelberg Univ. (Germany). Inst. of Human Genetics and Anthropology

1992-03-01

Recently fluorescence in situ hybridization protocols have been developed which allow the paining of individual chromosomes using DNA-libraries from sorted human chromosomes. This approach has the particular advantage that radiation induced chromosome translocations can be easily detected, if chromosomes of distinctly different colors take part in the translocation event. To enhance the sensitivity of this approach two metaphase chromosome subsets A and B (A: chromosome 1, 2, 4, 8, 16; B: 3, 5, 9, 10, 13) were simultaneously painted in green and red color. Counterstaining of the chromosomes with DAPI resulted in a third subset which exhibited blue fluorescence only. Green-red, green-blue and red-blue translocation chromosomes could be easily detected after irradiation of lymphocyte cultures with {sup 137}Cs-{gamma}-rays. Analyses of painted chromosomes can be combined with conventional GTG-banding analyses. This new biological dosimeter should become useful to monitor both long term effects of single irradiation events and the cumulative effects of multiple or chronic irradiation exposure. In contrast to translocation scoring based on the analysis of banded chromosomes, this new approach has the particular advantage that a rapid, automated scoring of translocations can now be envisaged. (author).

The effect of caffeine posttreatment on X-ray-induced chromosomal aberrations in human blood lymphocytes in vitro

International Nuclear Information System (INIS)

Natarajan, A.T.; Obe, G.

1980-01-01

The potentiating effect of caffeine on X-ray-induced chromosomal aberrations in human blood lymphocytes has been investigated, with special reference to cell cycle stages (G0 and G2). Both quantitative and qualitative differences in the yield of chromosomal aberrations were detected in caffeine-posttreated cells, depending on the cell stage irradiated. The studies on caffeine potentiating effects on X-irradiated G0 lymphocytes from normal adults, newborns, Down syndrome patients, and an ataxia telangiectasia patient pointed to interindividual variations in the response to caffeine potentiation among normal probands and a very profound effect in ataxia cells. (orig.) [de

Integration sites of Epstein-Barr virus genome on chromosomes of human lymphoblastoid cell lines

Energy Technology Data Exchange (ETDEWEB)

Wuu, K.D.; Chen, Y.J.; Wang-Wuu, S. [Institute of Genetics, Taipei (Taiwan, Province of China)

1994-09-01

Epstein-Barr virus (EBV) is the pathogen of infectious mononucleosis. The viral genome is present in more than 95% of the African cases of Burkitt lymphoma and it is usually maintained in episomal form in the tumor cells. Viral integration has been described only for Nanalwa which is a Burkitt lymphoma cell line lacking episomes. In order to examine the role of EBV in the immortalization of human Blymphocytes, we investigated whether the EBV integration into the human genome is essential. If the integration does occur, we would like to know whether the integration is randomly distributed or whether the viral DNA integrates preferentially at certain sites. Fourteen in vitro immortalized human lymphoblastoid cell lines (LCLs) were examined by fluorescence in situ hybridization (FISH) with a biotinylated EBV BamHI w DNA fragment as probe. The episomal form of EBV DNA was found in all cells of these cell lines, while only about 65% of the cells have the integrated viral DNA. This might suggest that integration is not a pre-requisite for cell immortalization. Although all chromosomes, except Y, have been found with integrated viral genome, chromsomes 1 and 5 are the most frequent EBV DNA carrier (p<0.05). Nine chromosome bands, namely, 1p31, 1q31, 2q32, 3q13, 3q26, 5q14, 6q24, 7q31 and 12q21, are preferential targets for EBV integration (p<0.001). Eighty percent of the total 938 EBV hybridization signals were found to be at G-band-positive area. This suggests that the mechanism of EBV integration might be different from that of the retroviruses, which specifically integrate to G-band-negative areas. Thus, we conclude that the integration of EBV to host genome is non-random and it may have something to do with the structure of chromosome and DNA sequences.

Mechanisms of telomere loss and their consequences for chromosome instability

International Nuclear Information System (INIS)

Muraki, Keiko; Nyhan, Kristine; Han, Limei; Murnane, John P.

2012-01-01

The ends of chromosomes in mammals, called telomeres, are composed of a 6-bp repeat sequence, TTAGGG, which is added on by the enzyme telomerase. In combination with a protein complex called shelterin, these telomeric repeat sequences form a cap that protects the ends of chromosomes. Due to insufficient telomerase expression, telomeres shorten gradually with each cell division in human somatic cells, which limits the number of times they can divide. The extensive cell division involved in cancer cell progression therefore requires that cancer cells must acquire the ability to maintain telomeres, either through expression of telomerase, or through an alternative mechanism involving recombination. It is commonly thought that the source of many chromosome rearrangements in cancer cells is a result of the extensive telomere shortening that occurs prior to the expression of telomerase. However, despite the expression of telomerase, tumor cells can continue to show chromosome instability due to telomere loss. Dysfunctional telomeres in cancer cells can result from oncogene-induced replication stress, which results in double-strand breaks (DSBs) at fragile sites, including telomeres. DSBs near telomeres are especially prone to chromosome rearrangements, because telomeric regions are deficient in DSB repair. The deficiency in DSB repair near telomeres is also an important mechanism for ionizing radiation-induced replicative senescence in normal human cells. In addition, DSBs near telomeres can result in chromosome instability in mouse embryonic stem cells, suggesting that telomere loss can contribute to heritable chromosome rearrangements. Consistent with this possibility, telomeric regions in humans are highly heterogeneous, and chromosome rearrangements near telomeres are commonly involved in human genetic disease. Understanding the mechanisms of telomere loss will therefore provide important insights into both human cancer and genetic disease.

Mechanisms of telomere loss and their consequences for chromosome instability

Directory of Open Access Journals (Sweden)

Keiko eMuraki

2012-10-01

Full Text Available The ends of chromosomes in mammals, called telomeres, are composed of a 6 base pair repeat sequence, TTAGGG, which is added on by the enzyme telomerase. In combination with a protein complex called shelterin, these telomeric repeat sequences form a cap that protects the ends of chromosomes. Due to insufficient telomerase expression, telomeres shorten gradually with each cell division in human somatic cells, which limits the number of times they can divide. The extensive cell division involved in cancer cell progression therefore requires that cancer cells must acquire the ability to maintain telomeres, either through expression of telomerase, or through an alternative mechanism involving recombination. It is commonly thought that the source of many chromosome rearrangements in cancer cells is a result of the extensive telomere shortening that occurs prior to the expression of telomerase. However, despite the expression of telomerase, tumor cells can continue to show chromosome instability due to telomere loss. Dysfunctional telomeres in cancer cells can result from oncogene-induced replication stress, which results in double-strand breaks (DSBs at fragile sites, including telomeres. DSBs near telomeres are especially prone to chromosome rearrangements, because telomeric regions are deficient in DSB repair. The deficiency in DSB repair near telomeres is also an important mechanism for ionizing radiation-induced replicative senescence in normal human cells. In addition, DSBs near telomeres can result in chromosome instability in mouse embryonic stem cells, suggesting that telomere loss can contribute to heritable chromosome rearrangements. Consistent with this possibility, telomeric regions in humans are highly heterogeneous, and chromosome rearrangements near telomeres are commonly involved in human genetic disease. Understanding the mechanisms of telomere loss will therefore provide important insights into both human cancer and genetic disease.

Mechanisms of telomere loss and their consequences for chromosome instability

Energy Technology Data Exchange (ETDEWEB)

Muraki, Keiko; Nyhan, Kristine; Han, Limei; Murnane, John P., E-mail: jmurnane@radonc.ucsf.edu [Department of Radiation Oncology, University of California at San Francisco, San Francisco, CA (United States)

2012-10-04

The ends of chromosomes in mammals, called telomeres, are composed of a 6-bp repeat sequence, TTAGGG, which is added on by the enzyme telomerase. In combination with a protein complex called shelterin, these telomeric repeat sequences form a cap that protects the ends of chromosomes. Due to insufficient telomerase expression, telomeres shorten gradually with each cell division in human somatic cells, which limits the number of times they can divide. The extensive cell division involved in cancer cell progression therefore requires that cancer cells must acquire the ability to maintain telomeres, either through expression of telomerase, or through an alternative mechanism involving recombination. It is commonly thought that the source of many chromosome rearrangements in cancer cells is a result of the extensive telomere shortening that occurs prior to the expression of telomerase. However, despite the expression of telomerase, tumor cells can continue to show chromosome instability due to telomere loss. Dysfunctional telomeres in cancer cells can result from oncogene-induced replication stress, which results in double-strand breaks (DSBs) at fragile sites, including telomeres. DSBs near telomeres are especially prone to chromosome rearrangements, because telomeric regions are deficient in DSB repair. The deficiency in DSB repair near telomeres is also an important mechanism for ionizing radiation-induced replicative senescence in normal human cells. In addition, DSBs near telomeres can result in chromosome instability in mouse embryonic stem cells, suggesting that telomere loss can contribute to heritable chromosome rearrangements. Consistent with this possibility, telomeric regions in humans are highly heterogeneous, and chromosome rearrangements near telomeres are commonly involved in human genetic disease. Understanding the mechanisms of telomere loss will therefore provide important insights into both human cancer and genetic disease.

Chromosome condensation and segmentation

International Nuclear Information System (INIS)

Viegas-Pequignot, E.M.

1981-01-01

Some aspects of chromosome condensation in mammalians -humans especially- were studied by means of cytogenetic techniques of chromosome banding. Two further approaches were adopted: a study of normal condensation as early as prophase, and an analysis of chromosome segmentation induced by physical (temperature and γ-rays) or chemical agents (base analogues, antibiotics, ...) in order to show out the factors liable to affect condensation. Here 'segmentation' means an abnormal chromosome condensation appearing systematically and being reproducible. The study of normal condensation was made possible by the development of a technique based on cell synchronization by thymidine and giving prophasic and prometaphasic cells. Besides, the possibility of inducing R-banding segmentations on these cells by BrdU (5-bromodeoxyuridine) allowed a much finer analysis of karyotypes. Another technique was developed using 5-ACR (5-azacytidine), it allowed to induce a segmentation similar to the one obtained using BrdU and identify heterochromatic areas rich in G-C bases pairs [fr

Chromosomal aberrations and DNA damage in human populations exposed to the processing of electronics waste.

Science.gov (United States)

Liu, Qiang; Cao, Jia; Li, Ke Qiu; Miao, Xu Hong; Li, Guang; Fan, Fei Yue; Zhao, Yong Cheng

2009-05-01

It has been known that the pollutants of electronic wastes (E-wastes) can lead to severe pollution to the environment. It has been reported that about 50% to 80% of E-wastes from developed countries are exported to Asia and Africa. It has become a major global environmental problem to deal with 'E-wastes'. E-waste recycling has remained primitive in Jinghai, China. This not only produces enormous environmental pollution but also can bring about toxic or genotoxic effects on the human body, threatening the health of both current residents and future generations living in the local environment. The concentration of lead in the blood of children in the E-waste polluted area in China is higher than that of the control area. But little is known about the cytogenetic effect to human beings caused by the pollution of E-wastes. In the present study, experiments have been performed to investigate the genetics of permanent residents of three villages with numerous E-waste disposal sites and to analyze the harmful effects of exposure to E-wastes. In total, 171 villagers (exposed group) were randomly selected from permanent residents of three villages located in Jinghai County of Tianjin, China, where there has been massive disposal of E-wastes. Thirty villagers were selected from the neighboring towns without E-waste disposal sites to serve as controls. Chromosomal aberrations and cytokinesis blocking micronucleus were performed to detect the cytogenetic effect, dic + r (dicentric and ring chromosome), monomer, fragments (acentric fragments, minute chromosomes, and acentric rings), translocation, satellite, quadriradial, total aberrations, and micronuclear rate were scored for each subject. DNA damage was detected using comet assay; the DNA percentage in the comet tail (TDNA%), tail moment (TM), and Olive tail moment (OTM) were recorded to describe DNA damage to lymphocytes. The total chromosome aberration rates (5.50%) and micronuclear rates (16.99%) of the exposure group

Assessment of DNA damage and Chromosome aberration in human lymphocyte exposed to low dose radiation detected by FISH(Fluorescence In Situ Hybridization) and SCGE(Single Cell Gel Electrophoresis)

International Nuclear Information System (INIS)

Chung, Hai Won; Kim, Su Young; Kim, Byung Mo; Kim, Sun Jin; Ha, Sung Whan; Kim, Tae Hwan; Cho, Chul Koo

2000-01-01

Comparative study was performed for the assessment of DNA damage and Chromosomal aberration in human lymphocyte exposed to low dose radiation using Fluorescence In Situ Hybridization(FISH) and Single Cell Gel Electrophoresis(SCGE). Chromosomal aberrations in human lymphocyte exposed to radiation at doses of 5, 10, 30 and 50cGy were analysed with whole chromosome-specific probes by human chromosome 1, 2 and 4 according to PAINT system. FISH with chromosome-specific probe has been used to be a valid and rapid method for detection of chromosome rearrangements induced by low dose radiation. The frequencies of stable translocation per cell equivalents were 0.0116, 0.0375, 0.0407, 0.0727 and 0.0814 for 0, 5, 10, 30 and 50cGy, respectively, and those of dicentric were 0.00, 0.0125, 0.174, 0.0291 and 0.0407 respectively. Radiation induced DNA damage in human lymphocyte in a dose-dependent manner at low doses from 5cGy to 50cGy, which were analysed by single Cell Gel Electrophoresis(SCGE). From above results, FISH seemed to be useful for radiation biodosimetry by which the frequencies of stable aberrations in human lymphocyte can be observed more easily than by conventional method and SCGE also seemed to be sensitive method for detecting DNA damage by low dose radiation exposure, so that those methods will improve our technique to perform meaningful biodosimetry for radiation at low doses

Shelterin Protects Chromosome Ends by Compacting Telomeric Chromatin

Science.gov (United States)

Bandaria, Jigar N.; Qin, Peiwu; Berk, Veysel; Chu, Steven; Yildiz, Ahmet

2016-01-01

SUMMARY Telomeres, repetitive DNA sequences at chromosome ends, are shielded against the DNA damage response (DDR) by the shelterin complex. To understand how shelterin protects telomere ends, we investigated the structural organization of telomeric chromatin in human cells using super-resolution microscopy. We found that telomeres form compact globular structures through a complex network of interactions between shelterin subunits and telomeric DNA, and not by DNA methylation, histone deacetylation or histone trimethylation at telomeres and subtelomeric regions. Mutations that abrogate shelterin assembly or removal of individual subunits from telomeres cause up to a 10-fold increase in telomere volume. Decompacted telomeres become more accessible to telomere-associated proteins and accumulate DDR signals. Recompaction of telomeric chromatin using an orthogonal method displaces DDR signals from telomeres. These results reveal the chromatin remodeling activity of shelterin and demonstrate that shelterin-mediated compaction of telomeric chromatin provides robust protection of chromosome ends against the DDR machinery. PMID:26871633

Reflections and meditations upon complex chromosomal exchanges.

Science.gov (United States)

Savage, John R K

2002-12-01

The application of FISH chromosome painting techniques, especially the recent mFISH (and its equivalents) where all 23 human chromosome pairs can be distinguished, has demonstrated that many chromosome-type structural exchanges are much more complicated (involving more "break-rejoins" and arms) than has hitherto been assumed. It is clear that we have been greatly under-estimating the damage produced in chromatin by such agents as ionising radiation. This article gives a brief historical summary of observations leading up to this conclusion, and after outlining some of the problems surrounding the formation of complex chromosomes exchanges, speculates about possible solutions currently being proposed.

Global chromosomal structural instability in a subpopulation of starving Escherichia coli cells.

Directory of Open Access Journals (Sweden)

Dongxu Lin

2011-08-01

Full Text Available Copy-number variations (CNVs constitute very common differences between individual humans and possibly all genomes and may therefore be important fuel for evolution, yet how they form remains elusive. In starving Escherichia coli, gene amplification is induced by stress, controlled by the general stress response. Amplification has been detected only encompassing genes that confer a growth advantage when amplified. We studied the structure of stress-induced gene amplification in starving cells in the Lac assay in Escherichia coli by array comparative genomic hybridization (aCGH, with polymerase chain reaction (pcr and DNA sequencing to establish the structures generated. About 10% of 300 amplified isolates carried other chromosomal structural change in addition to amplification. Most of these were inversions and duplications associated with the amplification event. This complexity supports a mechanism similar to that seen in human non-recurrent copy number variants. We interpret these complex events in terms of repeated template switching during DNA replication. Importantly, we found a significant occurrence (6 out of 300 of chromosomal structural changes that were apparently not involved in the amplification event. These secondary changes were absent from 240 samples derived from starved cells not carrying amplification, suggesting that amplification happens in a differentiated subpopulation of stressed cells licensed for global chromosomal structural change and genomic instability. These data imply that chromosomal structural changes occur in bursts or showers of instability that may have the potential to drive rapid evolution.

Late-replicating X-chromosome: replication patterns in mammalian females

Directory of Open Access Journals (Sweden)

Tunin Karen

2002-01-01

Full Text Available The GTG-banding and 5-BrdU incorporation patterns of the late-replicating X-chromosome were studied in female dogs and cattle, and compared to human female patterns. The replication patterns of the short arm of the X-chromosomes did not show any difference between human, dog and cattle females. As to the long arm, some bands showed differences among the three studied species regarding the replication kinetics pattern. These differences were observed in a restricted region of the X-chromosome, delimited by Xq11 -> q25 in humans, by Xq1 -> q8 in dogs, and by Xq12 -> q32 in cattle. In an attempt to find out if these differences in the replication kinetics could be a reflection of differences in the localization of genes in that region of the X-chromosome, we used the probe for the human androgen receptor gene (AR localized at Xq12, which is in the region where we observed differences among the three studied species. We did not, however, observe hybridization signals. Our study goes on, using other human probes for genes located in the region Xq11 -> Xq25.

Characterization of human chromosome 22 : Cloning of breakpoints of the constitutional translocation t(11;22)(q23;q11) and detection of small constitutional delections by microarray CGH

OpenAIRE

Tapia Paez, Isabel

2003-01-01

Chromosome 22 is the second smallest human chromosome, composing approximately 1.5% of the genome. The short arm of this acrocentric chromosome harbors ribosomal genes and the long arm contains the protein coding genes. This chromosome is gene-rich in comparison to the majority of other chromosomes, containing approximately 600 so far characterized genes. Many of these are involved in the etiology of a wide spectrum of diseases such as congenital and psychiatric disorders as...

Induction of chromosomal instability in human lymphoblasts by low doses of γ-radiation

International Nuclear Information System (INIS)

Gibbons, C.F.; Grosovsky, A.J.

2003-01-01

Full text: Genomic instability is a hallmark of tumorigenic progression, and a similar phenotype is also observed in a high fraction (10 - 50%) of cells that survive exposure to ionizing radiation. In both cases unstable clones are characterized by non-clonal chromosomal rearrangements, which are indicative of a high rate of genetic change during the outgrowth of an unstable parental cell. We postulate that the remarkably high frequency of radiation-induced genomic instability is incompatible with a mutational mechanism for a specific gene, or even a large family of genes. Rather, we hypothesize that a major portion of instability is attributable to the formation of chromosomal rearrangement junction sequences that act as de novo chromosomal breakage hotspots. We further suggest that critical target sequences, which represent at least 10% of the genome and include repetitive DNA sequences such as those found in centromeric heterochromatin, can be involved in breakage and rearrangement hotspots that drive persistent genomic instability and karyotypic heterogeneity. Since chromosomal damage is induced even by low dose radiation exposure, we hypothesize that this phenotype can be efficiently induced at doses that are relevant to environmental, occupational, or medical exposure. In the present study, TK6 human B-lymphoblastoid cells were irradiated with 0, 10, 20 and 200cGy, in order to provide a set of data points for single, low dose exposures. Independent clones were analyzed karyotypically approximately 40 generations after radiation exposure. Preliminary results suggest that the fraction of clones exhibiting genomic instability after 20 cGy (0.16) is similar to and statistically indistinguishable from the fraction of unstable clones following 200 cGy (0.2) exposure. These findings support the hypothesis that instability following radiation, and perhaps also in cancer, primarily reflects non-mutational mechanisms

Hominoid chromosomal rearrangements on 17q map to complex regions of segmental duplication.

Science.gov (United States)

Cardone, Maria Francesca; Jiang, Zhaoshi; D'Addabbo, Pietro; Archidiacono, Nicoletta; Rocchi, Mariano; Eichler, Evan E; Ventura, Mario

2008-01-01

Chromosomal rearrangements, such as translocations and inversions, are recurrent phenomena during evolution, and both of them are involved in reproductive isolation and speciation. To better understand the molecular basis of chromosome rearrangements and their part in karyotype evolution, we have investigated the history of human chromosome 17 by comparative fluorescence in situ hybridization (FISH) and sequence analysis. Human bacterial artificial chromosome/p1 artificial chromosome probes spanning the length of chromosome 17 were used in FISH experiments on great apes, Old World monkeys and New World monkeys to study the evolutionary history of this chromosome. We observed that the macaque marker order represents the ancestral organization. Human, chimpanzee and gorilla homologous chromosomes differ by a paracentric inversion that occurred specifically in the Homo sapiens/Pan troglodytes/Gorilla gorilla ancestor. Detailed analyses of the paracentric inversion revealed that the breakpoints mapped to two regions syntenic to human 17q12/21 and 17q23, both rich in segmental duplications. Sequence analyses of the human and macaque organization suggest that the duplication events occurred in the catarrhine ancestor with the duplication blocks continuing to duplicate or undergo gene conversion during evolution of the hominoid lineage. We propose that the presence of these duplicons has mediated the inversion in the H. sapiens/P. troglodytes/G. gorilla ancestor. Recently, the same duplication blocks have been shown to be polymorphic in the human population and to be involved in triggering microdeletion and duplication in human. These results further support a model where genomic architecture has a direct role in both rearrangement involved in karyotype evolution and genomic instability in human.

Isolation of anonymous, polymorphic DNA fragments from human chromosome 22q12-qter

NARCIS (Netherlands)

J.P. Dumanski (Jan); A.H.M. Geurts van Kessel (Ad); M. Ruttledge (Martin); A. Wladis (Andreas); N. Sugawa (Noriaki); V.P. Collins (Peter); M. Nordenskjöld

1990-01-01

textabstractA series of 195 random chromosome 22-specific probes, equivalent to approximately 1% of the size of this chromosome, have been isolated from a chromosome 22-specific bacteriophage lambda genomic library. These probes were mapped to four different regions of chromosome 22 on a panel of

Loss of Y-chromosome does not correlate with age at onset of head and neck carcinoma: a case-control study

Energy Technology Data Exchange (ETDEWEB)

Silva Veiga, L.C. [Departamento de Genética, Instituto de Biociências, Universidade Estadual Paulista, Botucatu, SP (Brazil); Departamento de Clínica Médica, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil); Bérgamo, N.A. [Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, GO (Brazil); Reis, P.P. [Departamento de Cirurgia e Ortopedia, Faculdade de Medicina de Botucatu, Universidade Estadual Paulista, Botucatu, SP (Brazil); Kowalski, L.P. [Departamento de Cirurgia de Cabeça e Pescoço e Otorrinolaringologia, Hospital A.C. Camargo, São Paulo, SP (Brazil); Rogatto, S.R. [Laboratório NeoGene, Departamento de Urologia, Faculdade de Medicina de Botucatu, Universidade Estadual Paulista, Botucatu, SP (Brazil); Departamento de Pesquisa, Hospital A.C. Camargo,Fundação Antônio Prudente, São Paulo, SP (Brazil)

2012-01-20

Loss of Y-chromosome has been correlated with older age in males. Furthermore, current evidence indicates that Y-chromosome loss also occurs in several human tumors, including head and neck carcinomas. However, the association between Y nullisomy and the occurrence of neoplasias in elderly men has not been well established. In the present study, the association between Y-chromosome loss and head and neck carcinomas was evaluated by comparison to cells from peripheral blood lymphocytes and normal mucosa of cancer-free individuals matched for age using dual-color fluorescence in situ hybridization. Twenty-one patients ranging in age from 28 to 68 years were divided into five-year groups for comparison with 16 cancer-free individuals matched for age. The medical records of all patients were examined to obtain clinical and histopathological data. None of the patients had undergone radiotherapy or chemotherapy before surgery. In all groups, the frequency of Y-chromosome loss was higher among patients than among normal reference subjects (P < 0.0001) and was not age-dependent. These data suggest that Y-chromosome loss is a tumor-specific alteration not associated with advanced age in head and neck carcinomas.

Loss of Y-chromosome does not correlate with age at onset of head and neck carcinoma: a case-control study

International Nuclear Information System (INIS)

Silva Veiga, L.C.; Bérgamo, N.A.; Reis, P.P.; Kowalski, L.P.; Rogatto, S.R.

2012-01-01

Loss of Y-chromosome has been correlated with older age in males. Furthermore, current evidence indicates that Y-chromosome loss also occurs in several human tumors, including head and neck carcinomas. However, the association between Y nullisomy and the occurrence of neoplasias in elderly men has not been well established. In the present study, the association between Y-chromosome loss and head and neck carcinomas was evaluated by comparison to cells from peripheral blood lymphocytes and normal mucosa of cancer-free individuals matched for age using dual-color fluorescence in situ hybridization. Twenty-one patients ranging in age from 28 to 68 years were divided into five-year groups for comparison with 16 cancer-free individuals matched for age. The medical records of all patients were examined to obtain clinical and histopathological data. None of the patients had undergone radiotherapy or chemotherapy before surgery. In all groups, the frequency of Y-chromosome loss was higher among patients than among normal reference subjects (P < 0.0001) and was not age-dependent. These data suggest that Y-chromosome loss is a tumor-specific alteration not associated with advanced age in head and neck carcinomas

Chromosome mosaicism in hypomelanosis of Ito.

Science.gov (United States)

Ritter, C L; Steele, M W; Wenger, S L; Cohen, B A

1990-01-01

Our finding of chromosome mosaicism with a ring 22 in a retarded black boy with hypomelanosis of Ito prompted a review of this "syndrome." Most patients have a variety of non-dermal defects, particularly those affecting CNS function. Among karyotyped patients, most are chromosome mosaics of one sort or another. Hypomelanosis of Ito turns out to be a causable non-specific phenotype, i.e., a clinical marker for chromosome mosaicism of all different types in individuals with a dark enough skin to show lighter patches. Consequently, cytogenetic evaluation is indicated in all patients with this skin finding.

Chromosomes and irradiation: in vitro study of the action of X-rays on human lymphocytes