The complete sequence of human chromosome 5

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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).

[The effect of 3-aminobenzamide on the mitotic cycle of Chinese hamster cells cultured on a medium with 5-bromodeoxyuridine following ionizing radiation action].

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Kirillova, T V; Rozanov, Iu M; Spivak, I M

1992-01-01

A specific inhibitor of poly(ADP-ribose)polymerase-3-aminobenzamide (6 mM) has been shown to: 1) reduce survival of non-irradiated CHO-K1 cells, cultivated in medium containing 5-bromodeoxyuridine (10 mkM, BDU cells), and increase their radiosensitivity; 2) induce G2 delay in BDU cells while progressing through the cell cycle as analysed by the DNA flow cytometry; 3) increase to a great degree G2 delay in X-irradiated BDU cells. 3-Aminobenzamide is primarily effective when it is present during the first or two first cell cycles after the initial addition of BDU. The above data confirm the involvement, presumably an indirect one, of ADP-ribosylation in the DNA repair through affecting the chromatin structure.

Physical Mapping of Bread Wheat Chromosome 5A: An Integrated Approach

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Delfina Barabaschi

2015-11-01

Full Text Available The huge size, redundancy, and highly repetitive nature of the bread wheat [ (L.] genome, makes it among the most difficult species to be sequenced. To overcome these limitations, a strategy based on the separation of individual chromosomes or chromosome arms and the subsequent production of physical maps was established within the frame of the International Wheat Genome Sequence Consortium (IWGSC. A total of 95,812 bacterial artificial chromosome (BAC clones of short-arm chromosome 5A (5AS and long-arm chromosome 5A (5AL arm-specific BAC libraries were fingerprinted and assembled into contigs by complementary analytical approaches based on the FingerPrinted Contig (FPC and Linear Topological Contig (LTC tools. Combined anchoring approaches based on polymerase chain reaction (PCR marker screening, microarray, and sequence homology searches applied to several genomic tools (i.e., genetic maps, deletion bin map, neighbor maps, BAC end sequences (BESs, genome zipper, and chromosome survey sequences allowed the development of a high-quality physical map with an anchored physical coverage of 75% for 5AS and 53% for 5AL with high portions (64 and 48%, respectively of contigs ordered along the chromosome. In the genome of grasses, [ (L. Beauv.], rice ( L., and sorghum [ (L. Moench] homologs of genes on wheat chromosome 5A were separated into syntenic blocks on different chromosomes as a result of translocations and inversions during evolution. The physical map presented represents an essential resource for fine genetic mapping and map-based cloning of agronomically relevant traits and a reference for the 5A sequencing projects.

Frequencies of chromosomal aberrations and sister chromatid exchanges in the benthic worm Neanthes arenaceodentata exposed to ionizing radiation

International Nuclear Information System (INIS)

Harrison, F.L.; Rice, D.W. Jr.; Moore, D.H.

1984-07-01

Traditional bioassays are unsuitable for assessing sublethal effects from ocean disposal of low-level radioactive waste because mortality and phenotypic responses are not anticipated. We compared the usefulness of chromosomal aberration and sister chromatid exchange (SCE) induction as measures of low-level radiation effects in a sediment-dwelling marine worm, Neanthes arenaceodentata. The SCEs, in contrast to chromosomal aberrations, do not alter the overall chromosome morphology and in mammalian cells appear to be a more sensitive indicator of DNA alterations caused by environmental mutagens. Newly hatched larvae were exposed to two radiation-exposure regimes of either x rays at a high dose rate of 0.7 Gy (70 rad)/min for as long as 5.5 min or to 60 Co gamma rays at a low dose rate of from 4.8 x 10 -5 to 1.2 x 10 -1 Gy (0.0048 to 12 rad)/h for 24 h. After irradiation, the larvae were exposed to 3 x 10 -5 M bromodeoxyuridine (BrdUrd) for 28 h (x-ray-irradiated larvae) or for 54 h ( 60 Co-irradiated larvae). Larval cells were examined for the proportion of cells in first, second, and third or greater division. Frequencies of chromosomal aberrations and SCEs were determined in first and second division cells, respectively. Results from x-ray irradiation indicated that dose-related increases occur in chromosome and chromatid deletions, but a dose of equal or greater 2 Gy (equal to or greater than 200 rad) was required to observe a significant increase. Worm larvae receiving 60 Co irradiation showed elevated SCE frequencies with a significant increase of 0.6 Gy (60 rad). We suggest that both SCEs and chromosomal aberrations may be useful for measuring effects on genetic material induced by radiation. 56 references, 7 figures, 9 tables

The structure of chromosom 5 in interphase-nucleii of HeLa-cells

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Claussen, Jan

2010-01-01

In order to examine the structure of chromosoms during the interphase HeLa-cells were synchronised and preperated. In further steps visulaised we the chromosom5 with help of multicour-banding. It could be showed that the chromosom 5 has a similar structure during the interphase as a metaphase-chromosom.

A familial Cri-du-Chat/5p deletion syndrome resulted from rare maternal complex chromosomal rearrangements (CCRs and/or possible chromosome 5p chromothripsis.

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Heng Gu

Full Text Available Cri-du-Chat syndrome (MIM 123450 is a chromosomal syndrome characterized by the characteristic features, including cat-like cry and chromosome 5p deletions. We report a family with five individuals showing chromosomal rearrangements involving 5p, resulting from rare maternal complex chromosomal rearrangements (CCRs, diagnosed post- and pre-natally by comprehensive molecular and cytogenetic analyses. Two probands, including a 4½-year-old brother and his 2½-year- old sister, showed no diagnostic cat cry during infancy, but presented with developmental delay, dysmorphic and autistic features. Both patients had an interstitial deletion del(5(p13.3p15.33 spanning ≈ 26.22 Mb. The phenotypically normal mother had de novo CCRs involving 11 breakpoints and three chromosomes: ins(11;5 (q23;p14.1p15.31,ins(21;5(q21;p13.3p14.1,ins(21;5(q21;p15.31p15.33,inv(7(p22q32dn. In addition to these two children, she had three first-trimester miscarriages, two terminations due to the identification of the 5p deletion and one delivery of a phenotypically normal daughter. The unaffected daughter had the maternal ins(11;5 identified prenatally and an identical maternal allele haplotype of 5p. Array CGH did not detect any copy number changes in the mother, and revealed three interstitial deletions within 5p15.33-p13.3, in the unaffected daughter, likely products of the maternal insertions ins(21;5. Chromothripsis has been recently reported as a mechanism drives germline CCRs in pediatric patients with congenital defects. We postulate that the unique CCRs in the phenotypically normal mother could resulted from chromosome 5p chromothripsis, that further resulted in the interstitial 5p deletions in the unaffected daughter. Further high resolution sequencing based analysis is needed to determine whether chromothripsis is also present as a germline structural variation in phenotypically normal individuals in this family.

Replication labeling patterns and chromosome territories typical of mammalian nuclei are conserved in the early metazoan Hydra.

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Alexandrova, Olga; Solovei, Irina; Cremer, Thomas; David, Charles N

2003-12-01

To investigate the evolutionary conservation of higher order nuclear architecture previously described for mammalian cells we have analyzed the nuclear architecture of the simple polyp Hydra. These diploblastic organisms have large nuclei (8-10 microm) containing about 3x10(9) bp of DNA organized in 15 chromosome pairs. They belong to the earliest metazoan phylum and are separated from mammals by at least 600 million years. Single and double pulse labeling with halogenated nucleotides (bromodeoxyuridine, iododeoxyuridine and chlorodeoxyuridine) revealed striking similarities to the known sequence of replication labeling patterns in mammalian nuclei. These patterns reflect a persistent nuclear arrangement of early, mid-, and late replicating chromatin foci that could be identified during all stages of interphase over at least 5-10 cell generations. Segregation of labeled chromatids led after several cell divisions to nuclei with single or a few labeled chromosome territories. In such nuclei distinct clusters of labeled chromatin foci were separated by extended nuclear areas with non-labeled chromatin, which is typical of a territorial arrangement of interphase chromosomes. Our results indicate the conservation of fundamental features of higher order chromatin arrangements throughout the evolution of metazoan animals and suggest the existence of conserved mechanism(s) controlling this architecture.

Leukemia-related clonal chromosome aberrations observed in A-bomb survivors. Deletion in chromosome 5 and inversion in chromosome 14

International Nuclear Information System (INIS)

Ohtaki, Kazuo

1999-01-01

Chromosome aberrations were analyzed by G differentiation staining method on about 5,400 peripheral lymphocytes of 168 A-bomb survivors, of whom 143 had been exposed to mean DS86 dose of 2.05 Gy (exposed group) and of 25, 0 Gy (control) and results concerning clonal growth of abnormal cells were described in this paper. G band analysis of the aberrations in T-lymphocytes revealed that frequency of translocation in the exposed group increased to 17 times of the control and deletion, 5 times. Deletion in chromosome 5 where tumor-suppressor gene was present, [del(5q-)], was found in about 30% of total deletions. Since patients of myelodysplasia syndrome and acute myelogenic leukemia had the deletion in more than 50%, growth of cells possessing it was suggestive of the progression of pre-leukemic step. Frequency of inversion in chromosome 14, inv(14)(q11q32), was as high as 80% of total 118 inversions of T-ALL (T-acute lymphocyte leukemia) and T-CLL (T-chronic LL) types in the exposed group. Therefore, the inversion also can be a pre-leukemic step. However, it was suggested that these aberrations were not sufficient for crisis of the disease, which required other factors.(K.H.)

Fragile sites, dysfunctional telomere and chromosome fusions: What is 5S rDNA role?

Science.gov (United States)

Barros, Alain Victor; Wolski, Michele Andressa Vier; Nogaroto, Viviane; Almeida, Mara Cristina; Moreira-Filho, Orlando; Vicari, Marcelo Ricardo

2017-04-15

Repetitive DNA regions are known as fragile chromosomal sites which present a high flexibility and low stability. Our focus was characterize fragile sites in 5S rDNA regions. The Ancistrus sp. species shows a diploid number of 50 and an indicative Robertsonian fusion at chromosomal pair 1. Two sequences of 5S rDNA were identified: 5S.1 rDNA and 5S.2 rDNA. The first sequence gathers the necessary structures to gene expression and shows a functional secondary structure prediction. Otherwise, the 5S.2 rDNA sequence does not contain the upstream sequences that are required to expression, furthermore its structure prediction reveals a nonfunctional ribosomal RNA. The chromosomal mapping revealed several 5S.1 and 5S.2 rDNA clusters. In addition, the 5S.2 rDNA clusters were found in acrocentric and metacentric chromosomes proximal regions. The pair 1 5S.2 rDNA cluster is co-located with interstitial telomeric sites (ITS). Our results indicate that its clusters are hotspots to chromosomal breaks. During the meiotic prophase bouquet arrangement, double strand breaks (DSBs) at proximal 5S.2 rDNA of acrocentric chromosomes could lead to homologous and non-homologous repair mechanisms as Robertsonian fusions. Still, ITS sites provides chromosomal instability, resulting in telomeric recombination via TRF2 shelterin protein and a series of breakage-fusion-bridge cycles. Our proposal is that 5S rDNA derived sequences, act as chromosomal fragile sites in association with some chromosomal rearrangements of Loricariidae. Copyright © 2017 Elsevier B.V. All rights reserved.

Discrimination of chromosome by autoradiography

International Nuclear Information System (INIS)

Masubuchi, Masanori

1975-01-01

This paper describes discrimination of chromosome by autoradiography. In this method, the difference in DNA synthetic phase between each chromosome was used as a standard, and the used chromosome was in metaphase, as morphological characteristics were markedly in this phase. Cell cycle and autoradiography with 3 H-thymidine were also examined. In order to discriminate chromosome by autoradiography, it was effective to utilize the labelled pattern in late DNA synthetic phase, where asynchronous replication of chromosome appeared most obviously. DNA synthesis in chromosome was examined in each DNA synthetic phase by culturing the chromosome after the treatment with 3 H-thymidine and altering the time to prepare chromosome specimen. Discrimination of chromosome in plants and animals by autoradiography was also mentioned. It was noticed as a structural and functional discrimination of chromosome to observe amino acid uptake into chromosome protein and to utilize the difference in labelled pattern between the sites of chromosome. (K. Serizawa)

Interleukin 3 gene is located on human chromosome 5 and is deleted in myeloid leukemias with a deletion of 5q

International Nuclear Information System (INIS)

Le Beau, M.M.; Epstein, N.D.; O'Brien, S.J.; Nienhuis, A.W.; Yang, Y.C.; Clark, S.C.; Rowley, J.D.

1987-01-01

The gene IL-3 encodes interleukin 3, a hematopoietic colony-stimulating factor (CSF) that is capable of supporting the proliferation of a broad range of hematopoietic cell types. By using somatic cell hybrids and in situ chromosomal hybridization, the authors localized this gene to human chromosome 5 at bands q23-31, a chromosomal region that is frequently deleted [del(5q)] in patients with myeloid disorders. By in situ hybridization, IL-3 was found to be deleted in the 5q-chromosome of one patient with refractory anemia who had a del(5)(q15q33.3), of three patients with refractory anemia (two patients) or acute nonlymphocytic leukemia (ANLL) de novo who had a similar distal breakpoint [del(5)(q13q33.3)], and of a fifth patient, with therapy-related ANLL, who had a similar distal breakpoint in band q33[del(5)(q14q33.3)]. Southern blot analysis of somatic cell hybrids retaining the normal or the deleted chromosome 5 from two patients with the refractory anemia 5q- syndrome indicated that IL-3 sequences were absent from the hybrids retaining the deleted chromosome 5 but not from hybrids that had a cytologically normal chromosome 5. Thus, a small segment of chromosome 5 contains IL-3, GM-CSF, CSF-1, and FMS. The findings and earlier results indicating that GM-CSF, CSF-1, and FMS were deleted in the 5q- chromosome, suggest that loss of IL-3 or of other CSF genes may play an important role in the pathogenesis of hematologic disorders associated with a del(5q)

Comparison of the chromosome maps around a resistance hot spot on chromosome 5 of potato and tomato using BAC-FISH painting.

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Achenbach, Ute C; Tang, Xiaomin; Ballvora, Agim; de Jong, Hans; Gebhardt, Christiane

2010-02-01

Potato chromosome 5 harbours numerous genes for important qualitative and quantitative traits, such as resistance to the root cyst nematode Globodera pallida and the late blight fungus, Phytophthora infestans. The genes make up part of a "hot spot" for resistances to various pathogens covering a genetic map length of 3 cM between markers GP21 and GP179. We established the physical size and position of this region on chromosome 5 in potato and tomato using fluorescence in situ hybridization (FISH) on pachytene chromosomes. Five potato bacterial artificial chromosome (BAC) clones with the genetically anchored markers GP21, R1-contig (proximal end), CosA, GP179, and StPto were selected, labeled with different fluorophores, and hybridized in a five-colour FISH experiment. Our results showed the location of the BAC clones in the middle of the long arm of chromosome 5 in both potato and tomato. Based on chromosome measurements, we estimate the physical size of the GP21-GP179 interval at 0.85 Mb and 1.2 Mb in potato and tomato, respectively. The GP21-GP179 interval is part of a genome segment known to have inverted map positions between potato and tomato.

Utilisation de l'essai comete et du biomarqueur gamma-H2AX pour detecter les dommages induits a l'ADN cellulaire par le 5-bromodeoxyuridine post-irradiation

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La Madeleine, Carole

Ce memoire est presente a la Faculte de medecine et des sciences de la sante de l'Universite de Sherbrooke en vue de l'obtention du grade de maitre es sciences (M.Sc.) en radiobiologie (2009). Un jury a revise les informations contenues dans ce memoire. Il etait compose de professeurs de la Faculte de medecine et des sciences de la sante soit : Darel Hunting PhD, directeur de recherche (departement de medecine nucleaire et radiobiologie), Leon Sanche PhD, directeur de recherche (departement de medecine nucleaire et radiobiologie), Richard Wagner PhD, membre du programme (departement de medecine nucleaire et radiobiologie) et Guylain Boissonneault PhD, membre exterieur au programme (departement de biochimie). Le 5-bromodeoxyuridine (BrdU), un analogue halogene de la thymidine reconnu depuis les annees 60 comme etant un excellent radiosensibilisateur. L'hypothese la plus repandue au sujet de l'effet radio sensibilisant du BrdU est qu'il augmente le nombre de cassures simple et double brin lorsqu'il est incorpore dans l'ADN de la cellule et expose aux radiations ionisantes. Toutefois, de nouvelles recherches semblent remettre en question les observations precedentes. Ces dernieres etudes ont confirme que le BrdU est un bon radiosensibilisateur, car il augmente les dommages radio-induits dans l'ADN. Mais, c'est en etant incorpore dans une region simple brin que le BrdU radiosensibilise l'ADN. Ces recherches ont egalement revele pour la premiere fois un nouveau type de dommages produits lors de l'irradiation de l'ADN contenant du BrdU : les dimeres interbrins. Le but de ces travaux de recherche est de determiner si la presence de bromodeoxyuridine dans l'ADN augmente l'induction de bris simple et / ou double brin chez les cellules irradiees en utilisant de nouvelles techniques plus sensibles et specifiques que celles utilisees auparavant. Pour ce faire, les essais cometes et la detection des foci H2AX phosphorylee pourraient permettre d'etablir les effets engendres par

Critical target and dose and dose-rate responses for the induction of chromosomal instability by ionizing radiation

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Limoli, C. L.; Corcoran, J. J.; Milligan, J. R.; Ward, J. F.; Morgan, W. F.

1999-01-01

To investigate the critical target, dose response and dose-rate response for the induction of chromosomal instability by ionizing radiation, bromodeoxyuridine (BrdU)-substituted and unsubstituted GM10115 cells were exposed to a range of doses (0.1-10 Gy) and different dose rates (0.092-17.45 Gy min(-1)). The status of chromosomal stability was determined by fluorescence in situ hybridization approximately 20 generations after irradiation in clonal populations derived from single progenitor cells surviving acute exposure. Overall, nearly 700 individual clones representing over 140,000 metaphases were analyzed. In cells unsubstituted with BrdU, a dose response was found, where the probability of observing delayed chromosomal instability in any given clone was 3% per gray of X rays. For cells substituted with 25-66% BrdU, however, a dose response was observed only at low doses (1.0 Gy), the incidence of chromosomal instability leveled off. There was an increase in the frequency and complexity of chromosomal instability per unit dose compared to cells unsubstituted with BrdU. The frequency of chromosomal instability appeared to saturate around approximately 30%, an effect which occurred at much lower doses in the presence of BrdU. Changing the gamma-ray dose rate by a factor of 190 (0.092 to 17.45 Gy min(-1)) produced no significant differences in the frequency of chromosomal instability. The enhancement of chromosomal instability promoted by the presence of the BrdU argues that DNA comprises at least one of the critical targets important for the induction of this end point of genomic instability.

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

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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.

Effects of radiation on frequency of chromosomal aberrations and sister chromatid exchange in the benthic worm Neanthes arenaceodentata

International Nuclear Information System (INIS)

Harrison, F.L.; Rice, D.W. Jr.; Moore, D.H.; Varela, M.

1983-04-01

Traditional bioassays are unsuitable for assessing sublethal effects of low levels of radioactivity because mortality and phenotypic responses are not anticipated. We compared the usefulness of chromosomal aberration (CA) and sister chromatid exchange (SCE) induction as measures of low-level radiation effects in a sediment-dwelling marine worm, Neanthes arenaceodentata. Newly hatched larvae were exposed to two radiation exposure regimes. Groups of 100 larvae were exposed to either x rays delivered at high dose rates (0.7 Gy min -1 ) or to 60 Co gamma rays delivered at low dose rates (4.8 X 10 -5 to 1.2 X 10 -1 Gy h -1 ). After irradiation, the larvae were exposed to 3 X 10 -5 M bromodeoxyuridine (BrdUrd) for 28 h (x-ray-irradiated larvae) or for 54 h ( 60 Co-irradiated larvae). Slides of larval cells were prepared for observation of CAs and SCEs. Frequencies of CAs were determined in first division cells; frequencies of SCEs were determined in second division cells. Results from x-ray irradiation indicated that dose-related increases occur in chromosome and chromatid deletions, but an x-ray dose greater than or equal to 2 Gy was required to observe a significant increase. Worm larvae receiving 60 Co irradiation showed elevated SCE frequencies; a significant increase in SCE frequency was observed at 0.6 Gy. 49 references, 2 figures

Features of the organization of bread wheat chromosome 5BS based on physical mapping.

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Salina, Elena A; Nesterov, Mikhail A; Frenkel, Zeev; Kiseleva, Antonina A; Timonova, Ekaterina M; Magni, Federica; Vrána, Jan; Šafář, Jan; Šimková, Hana; Doležel, Jaroslav; Korol, Abraham; Sergeeva, Ekaterina M

2018-02-09

The IWGSC strategy for construction of the reference sequence of the bread wheat genome is based on first obtaining physical maps of the individual chromosomes. Our aim is to develop and use the physical map for analysis of the organization of the short arm of wheat chromosome 5B (5BS) which bears a number of agronomically important genes, including genes conferring resistance to fungal diseases. A physical map of the 5BS arm (290 Mbp) was constructed using restriction fingerprinting and LTC software for contig assembly of 43,776 BAC clones. The resulting physical map covered ~ 99% of the 5BS chromosome arm (111 scaffolds, N50 = 3.078 Mb). SSR, ISBP and zipper markers were employed for anchoring the BAC clones, and from these 722 novel markers were developed based on previously obtained data from partial sequencing of 5BS. The markers were mapped using a set of Chinese Spring (CS) deletion lines, and F2 and RICL populations from a cross of CS and CS-5B dicoccoides. Three approaches have been used for anchoring BAC contigs on the 5BS chromosome, including clone-by-clone screening of BACs, GenomeZipper analysis, and comparison of BAC-fingerprints with in silico fingerprinting of 5B pseudomolecules of T. dicoccoides. These approaches allowed us to reach a high level of BAC contig anchoring: 96% of 5BS BAC contigs were located on 5BS. An interesting pattern was revealed in the distribution of contigs along the chromosome. Short contigs (200-999 kb) containing markers for the regions interrupted by tandem repeats, were mainly localized to the 5BS subtelomeric block; whereas the distribution of larger 1000-3500 kb contigs along the chromosome better correlated with the distribution of the regions syntenic to rice, Brachypodium, and sorghum, as detected by the Zipper approach. The high fingerprinting quality, LTC software and large number of BAC clones selected by the informative markers in screening of the 43,776 clones allowed us to significantly increase the

Higher 5-hydroxymethylcytosine identifies immortal DNA strand chromosomes in asymmetrically self-renewing distributed stem cells.

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Huh, Yang Hoon; Cohen, Justin; Sherley, James L

2013-10-15

Immortal strands are the targeted chromosomal DNA strands of nonrandom sister chromatid segregation, a mitotic chromosome segregation pattern unique to asymmetrically self-renewing distributed stem cells (DSCs). By nonrandom segregation, immortal DNA strands become the oldest DNA strands in asymmetrically self-renewing DSCs. Nonrandom segregation of immortal DNA strands may limit DSC mutagenesis, preserve DSC fate, and contribute to DSC aging. The mechanisms responsible for specification and maintenance of immortal DNA strands are unknown. To discover clues to these mechanisms, we investigated the 5-methylcytosine and 5-hydroxymethylcytosine (5hmC) content on chromosomes in mouse hair follicle DSCs during nonrandom segregation. Although 5-methylcytosine content did not differ significantly, the relative content of 5hmC was significantly higher in chromosomes containing immortal DNA strands than in opposed mitotic chromosomes containing younger mortal DNA strands. The difference in relative 5hmC content was caused by the loss of 5hmC from mortal chromosomes. These findings implicate higher 5hmC as a specific molecular determinant of immortal DNA strand chromosomes. Because 5hmC is an intermediate during DNA demethylation, we propose a ten-eleven translocase enzyme mechanism for both the specification and maintenance of nonrandomly segregated immortal DNA strands. The proposed mechanism reveals a means by which DSCs "know" the generational age of immortal DNA strands. The mechanism is supported by molecular expression data and accounts for the selection of newly replicated DNA strands when nonrandom segregation is initiated. These mechanistic insights also provide a possible basis for another characteristic property of immortal DNA strands, their guanine ribonucleotide dependency.

Metaphase chromosome and nucleoid differences between CHO-K1 and its radiosensitive derivative xrs-5

International Nuclear Information System (INIS)

Schwartz, J.L.; Stephens, J.; Vaughan, A.T.M.

1992-05-01

The Chinese hamster ovary (CHO) cell line xrs-5 is a radiation-sensitive mutant isolated from CHO-K1 cells. The radiation sensitivity is associated with a defect in DNA double-strand break rejoining. Chromatin structure also appears altered in xrs-5 cells compared to the parental CHO-K1 cells. Metaphase chromosomes from xrs-5 are more condensed in appearance than CHO-K1 chromosomes. The overcondensed look is not the result of colcemid sensitivity. Electron microscopy studies suggest that xrs-5 metaphase chromosomes have larger loops of chromatin extending out from the chromosome core. There are also differences between CHO-K1 and xrs-5 cells in the size and fluorescence pattern of ethidium bromide-stained nucleoid preparations. These results suggest that there is a fundamental difference between CHO-K1 and xrs-5 in either the organization of the supercoiled loops of DNA attached to the nuclear matrix or in the nature of the proteins that attach the DNA to the matrix. These alterations in chromosome structure may underlie, in part, the radiation sensitivity of xrs-5 cells

Metaphase chromosome and nucleoid differences between CHO-K1 and its radiosensitive derivative xrs-5

International Nuclear Information System (INIS)

Schwartz, J.L.; Stephens, J.; Vaughan, A.T.M.

1993-01-01

The Chinese hamster ovary (CHO) cell line xrs-5 is a radiation-sensitive mutant isolated from CHO-K1 cells. The radiosensitivity is associated with a defect in DNA double-strand break rejoining. Chromatin structure also appears altered in xrs-5 cells compared with the parental CHO-K1 cells. Metaphase chromosomes form xrs-5 are more condensed in appearance than CHO-K1 chromosomes. The overcondensed look is not the result of colcemid sensitivity. Electron microscopy studies suggest that xrs-5 metaphase chromosomes have larger loops of chromatin extending out from the chromosome core. There are also differences between CHO-K1 and xrs-5 cells in the size and fluorescence pattern of ethidium bromide-stained nucleoid preparations. These results suggest that there is a fundamental difference between CHO-K1 and xrs-5 in either the organization of the supercoiled loops of DNA attached to the nuclear matrix or in the nature of the proteins that attach the DNA to the matrix. These alterations in chromosome structure may underlie, in part the radiation sensitivity of xrs-5 cells. (Author)

Destabilized SMC5/6 complex leads to chromosome breakage syndrome with severe lung disease

Science.gov (United States)

van der Crabben, Saskia N.; Hennus, Marije P.; McGregor, Grant A.; Ritter, Deborah I.; Nagamani, Sandesh C.S.; Wells, Owen S.; Harakalova, Magdalena; Chinn, Ivan K.; Alt, Aaron; Vondrova, Lucie; Hochstenbach, Ron; van Montfrans, Joris M.; Terheggen-Lagro, Suzanne W.; van Lieshout, Stef; van Roosmalen, Markus J.; Renkens, Ivo; Duran, Karen; Nijman, Isaac J.; Kloosterman, Wigard P.; Hennekam, Eric; van Hasselt, Peter M.; Wheeler, David A.; Palecek, Jan J.; Lehmann, Alan R.; Oliver, Antony W.; Pearl, Laurence H.; Plon, Sharon E.; Murray, Johanne M.

2016-01-01

The structural maintenance of chromosomes (SMC) family of proteins supports mitotic proliferation, meiosis, and DNA repair to control genomic stability. Impairments in chromosome maintenance are linked to rare chromosome breakage disorders. Here, we have identified a chromosome breakage syndrome associated with severe lung disease in early childhood. Four children from two unrelated kindreds died of severe pulmonary disease during infancy following viral pneumonia with evidence of combined T and B cell immunodeficiency. Whole exome sequencing revealed biallelic missense mutations in the NSMCE3 (also known as NDNL2) gene, which encodes a subunit of the SMC5/6 complex that is essential for DNA damage response and chromosome segregation. The NSMCE3 mutations disrupted interactions within the SMC5/6 complex, leading to destabilization of the complex. Patient cells showed chromosome rearrangements, micronuclei, sensitivity to replication stress and DNA damage, and defective homologous recombination. This work associates missense mutations in NSMCE3 with an autosomal recessive chromosome breakage syndrome that leads to defective T and B cell function and acute respiratory distress syndrome in early childhood. PMID:27427983

Cryptorchidism due to chromosome 5q inversion duplication.

Science.gov (United States)

Dutta, M K; Gundgurthi, A; Garg, M K; Pakhetr, R

2013-12-01

We present a 15 year old boy who was born out of a non consanguineous marriage, and presented with bilateral cryptorchidism, mental retardation, facial dysmorphism, hypergonadotrophic hypogonadism with failure of anatomical and biochemical localisation of testes. Karyotype analysis showed 46 XY with inverted duplication on chromosome 5q22-31.

Fibroadenoma in Beckwith-Wiedemann syndrome with paternal uniparental disomy of chromosome 11p15.5.

Science.gov (United States)

Takama, Yuichi; Kubota, Akio; Nakayama, Masahiro; Higashimoto, Ken; Jozaki, Kosuke; Soejima, Hidenobu

2014-12-01

Herein is described a case of breast fibroadenomas in a 16-year-old girl with Beckwith-Wiedemann syndrome (BWS) and uniparental disomy (UPD) of chromosome 11p15.5. She was clinically diagnosed with BWS and direct closure was performed for an omphalocele at birth. Subtotal and 90% pancreatectomy were performed for nesidioblastosis at the ages 2 months and 8 years, respectively. Bilateral multiple breast fibroadenomas were noted at the age of 16 and 17 years. In this case, paternal UPD of chromosome 11p15.5 was identified on microsatellite marker analysis. The relevant imprinted chromosomal region in BWS is 11p15.5, and UPD of chromosome 11p15 is a risk factor for BWS-associated tumorigenicity. Chromosome 11p15.5 consists of imprinting domains of IGF2, the expression of which is associated with the tumorigenesis of various breast cancers. This case suggests that fibroadenomas occurred in association with BWS. © 2014 Japan Pediatric Society.

Phylogeny of horse chromosome 5q in the genus Equus and centromere repositioning.

Science.gov (United States)

Piras, F M; Nergadze, S G; Poletto, V; Cerutti, F; Ryder, O A; Leeb, T; Raimondi, E; Giulotto, E

2009-01-01

Horses, asses and zebras belong to the genus Equus and are the only extant species of the family Equidae in the order Perissodactyla. In a previous work we demonstrated that a key factor in the rapid karyotypic evolution of this genus was evolutionary centromere repositioning, that is, the shift of the centromeric function to a new position without alteration of the order of markers along the chromosome. In search of previously undiscovered evolutionarily new centromeres, we traced the phylogeny of horse chromosome 5, analyzing the order of BAC markers, derived from a horse genomic library, in 7 Equus species (E. caballus, E. hemionus onager, E. kiang, E. asinus, E. grevyi, E. burchelli and E. zebra hartmannae). This analysis showed that repositioned centromeres are present in E. asinus (domestic donkey, EAS) chromosome 16 and in E. burchelli (Burchell's zebra, EBU) chromosome 17, confirming that centromere repositioning is a strikingly frequent phenomenon in this genus. The observation that the neocentromeres in EAS16 and EBU17 are in the same chromosomal position suggests that they may derive from the same event and therefore, E. asinus and E. burchelli may be more closely related than previously proposed; alternatively, 2 centromere repositioning events, involving the same chromosomal region, may have occurred independently in different lineages, pointing to the possible existence of hot spots for neocentromere formation. Our comparative analysis also showed that, while E. caballus chromosome 5 seems to represent the ancestral configuration, centric fission followed by independent fusion events gave rise to 3 different submetacentric chromosomes in other Equus lineages. (c) 2009 S. Karger AG, Basel.

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.

The 5S rDNA in two Abracris grasshoppers (Ommatolampidinae: Acrididae): molecular and chromosomal organization.

Science.gov (United States)

Bueno, Danilo; Palacios-Gimenez, Octavio Manuel; Martí, Dardo Andrea; Mariguela, Tatiane Casagrande; Cabral-de-Mello, Diogo Cavalcanti

2016-08-01

The 5S ribosomal DNA (rDNA) sequences are subject of dynamic evolution at chromosomal and molecular levels, evolving through concerted and/or birth-and-death fashion. Among grasshoppers, the chromosomal location for this sequence was established for some species, but little molecular information was obtained to infer evolutionary patterns. Here, we integrated data from chromosomal and nucleotide sequence analysis for 5S rDNA in two Abracris species aiming to identify evolutionary dynamics. For both species, two arrays were identified, a larger sequence (named type-I) that consisted of the entire 5S rDNA gene plus NTS (non-transcribed spacer) and a smaller (named type-II) with truncated 5S rDNA gene plus short NTS that was considered a pseudogene. For type-I sequences, the gene corresponding region contained the internal control region and poly-T motif and the NTS presented partial transposable elements. Between the species, nucleotide differences for type-I were noticed, while type-II was identical, suggesting pseudogenization in a common ancestor. At chromosomal point to view, the type-II was placed in one bivalent, while type-I occurred in multiple copies in distinct chromosomes. In Abracris, the evolution of 5S rDNA was apparently influenced by the chromosomal distribution of clusters (single or multiple location), resulting in a mixed mechanism integrating concerted and birth-and-death evolution depending on the unit.

Linkage and QTL mapping for Sus scrofa chromosome 5

Czech Academy of Sciences Publication Activity Database

Lee, S. S.; Chen, Y.; Moran, C.; Stratil, Antonín; Reiner, G.; Bartenschlager, H.; Moser, G.; Geldermann, H.

2003-01-01

Roč. 120, č. 1 (2003), s. 38-44 ISSN 0931-2668 R&D Projects: GA ČR GA523/97/1305 Institutional research plan: CEZ:AV0Z5045916 Keywords : chromosome 5 Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 0.634, year: 2003

An enzyme-linked immunosorbent assay for bromodeoxyuridine incorporation using fixed microcultures

International Nuclear Information System (INIS)

Muir, D.; Varon, S.; Manthorpe, M.

1990-01-01

We report a quantitative method by which a single microculture can be examined for cell morphology; cell number; DNA synthesis; and expression of cell antigens. This method first involves measuring by enzyme-linked immunosorbent assay (ELISA) the total bromodeoxyuridine (BrdU) incorporation into DNA by monolayer microcultures. The BrdU-ELISA measurement was followed by simultaneous immunostaining for BrdU-positive nuclei and for a cytoplasmic antigen. The method was applied to the measurement of mitogen-induced proliferation of rat sciatic nerve Schwann cell and cerebral astroglia microcultures. The ELISA measurement of BrdU incorporation compares favorably with measurements of tritiated thymidine incorporation and offers the additional advantages that the same microculture can subsequently be examined for cell number, for cell morphology, and for the percentage of cells having BrdU-labeled nuclei and other antigens

An enzyme-linked immunosorbent assay for bromodeoxyuridine incorporation using fixed microcultures

Energy Technology Data Exchange (ETDEWEB)

Muir, D.; Varon, S.; Manthorpe, M. (Univ. of California, San Diego, La Jolla (USA))

1990-03-01

We report a quantitative method by which a single microculture can be examined for cell morphology; cell number; DNA synthesis; and expression of cell antigens. This method first involves measuring by enzyme-linked immunosorbent assay (ELISA) the total bromodeoxyuridine (BrdU) incorporation into DNA by monolayer microcultures. The BrdU-ELISA measurement was followed by simultaneous immunostaining for BrdU-positive nuclei and for a cytoplasmic antigen. The method was applied to the measurement of mitogen-induced proliferation of rat sciatic nerve Schwann cell and cerebral astroglia microcultures. The ELISA measurement of BrdU incorporation compares favorably with measurements of tritiated thymidine incorporation and offers the additional advantages that the same microculture can subsequently be examined for cell number, for cell morphology, and for the percentage of cells having BrdU-labeled nuclei and other antigens.

The chromosomal constitution of fish hybrid lineage revealed by 5S rDNA FISH.

Science.gov (United States)

Zhang, Chun; Ye, Lihai; Chen, Yiyi; Xiao, Jun; Wu, Yanhong; Tao, Min; Xiao, Yamei; Liu, Shaojun

2015-12-03

The establishment of the bisexual fertile fish hybrid lineage including the allodiploid and allotetraploid hybrids, from interspecific hybridization of red crucian carp (Carassius auratus red var. 2n = 100, 2n = AA) (♀) × common carp (Cyprinus carpio L. 2n = 100, 2n = BB) (♂), provided a good platform to investigate genetic relationship between the parents and their hybrid progenies. The chromosomal inheritance of diploid and allotetraploid hybrid progenies in successive generations, was studied by applying 5S rDNA fluorescence in situ hybridization. Signals of 5S rDNA distinguished the chromosomal constitution of common carp (B-genome) from red crucian carp (A-genome), in which two strong signals were observed on the first submetacentric chromosome, while no major signal was found in common carp. After fish hybridization, one strong signal of 5S rDNA was detected in the same locus on the chromosome of diploid hybrids. As expected, two strong signals were observed in 4nF3 tetraploid hybrids offspring and it is worth mentioning that two strong signals were detected in a separating bivalent of a primary spermatocyte in 4nF3. Furthermore, the mitosis of heterozygous chromosomes was shown normal and stable with blastular tissue histological studies. We revealed that 5S rDNA signal can be applied to discern A-genome from B-genome, and that 5S rDNA bearing chromosomes can be stably passed down in successive generations. Our work provided a significant method in fish breeding and this is important for studies in fish evolutionary biology.

Studies with bromodeoxyuridine in head and neck cancer and accelerated radiotherapy

International Nuclear Information System (INIS)

Wilson, George D.; Dische, Stanley; Saunders, Michele I.

1995-01-01

Using bromodeoxyuridine (BrdUrd), tumour cell proliferation was assessed, by flow cytometric (FCM) and immunohistochemical methods, in patients treated by the CHART regime of radiotherapy. Of 115 cases studied, data were complete in 90 using both methods. No cell kinetic-related parameter predicted the outcome of patients treated by CHART, in keeping with the view that, with this regime, cellular proliferation had been minimised as a cause of failure. Histological evaluation of the labelling index (LI) revealed a trend for higher LI is in diploid tumours (16.2%) than in aneuploid (13.8%), contrasting to that found by FCM (5.0 and 9.3% respectively). When the T pot was calculated using a combination of histology LI and FCM T S , diploid tumours showed more rapid proliferation (T pot 1.8 days) than aneuploid tumours (T pot 3.2 days); this finding was significant (p < 0.02). A novel parameter, termed proliferation pattern, unique to these studies with BrdUrd in vivo, was assessed. Both proliferation pattern and histological grading had predictive power to discriminate the outcome in univariate analysis (p = < 0.031 and 0.037, respectively). In a Cox multivariate analysis, proliferation pattern was the more important predictor. The studies reported highlight the extra information that can be gained from combining immunohistochemistry with flow cytometry to study the cellular proliferation of human tumours

Distamycin A/DAPI bands and the effects of 5-azacytidine on the chromosomes of the chimpanzee, Pan troglodytes.

Science.gov (United States)

Schmid, M; Haaf, T

1984-01-01

The chromosomes of the chimpanzee were stained with distamycin A/DAPI, which labels specific C-bands. Bright distamycin A/DAPI fluorescence was found in the heterochromatic regions of chromosomes 6, 11, 14 to 16, 18 to 20, and 23 and the Y. Lymphocyte cultures from chimpanzees were treated with low doses of 5-azacytidine during the last hours of culture. This cytosine analog induces highly distinct undercondensations in 28 heterochromatic regions of 19 chromosomes. These 5-azacytidine-sensitive regions are predominantly located in the terminal C-bands of the chromosomes. In vitro treatment with 5-azacytidine also preserves into the metaphase stage somatic pairings between the 5-azacytidine-sensitive heterochromatic regions in interphase nuclei. The homologies and differences regarding the chromosomal localization of distamycin A/DAPI-bright C-bands, 5-azacytidine-sensitive heterochromatin, 5-methylcytosine-rich DNA sequences, and satellite DNAs in the chimpanzee and man are discussed.

A case of refractory anemia with chromosomal abnormality (5q-) in Nagasaki atomic bomb survivor

International Nuclear Information System (INIS)

Kusano, Miyuki; Ikeda, Shuichi; Tomonaga, Yu; Sadamori, Naoki; Matsunaga, Masako

1978-01-01

Although assumed to be almost free from the effect of A-bomb radiation on the basis of the estimated dose, this case had progressive anemia with a specific manifestation and disclosed a clone with chromosomal abnormality (5q - ). In pure leukemia, a clone of abnormal chromosome is considered exactly that of leukemia. However, the presence of clones with chromosomal abnormality which are found in polycythemia vera or myelofibrosis do not always denote the leukemic changes. There is no established theory as to the significance of the clones with chromosomal abnormality in refractory anemia. Thus the interpretation of chromosomal abnormality in blood diseases is very difficult. Therefore analysis of chromosomes will be made actively in leukemia and related diseases as well as refractory anemia and preleukemia, and those will be compared in detail to search the relation between on occurrence of leukemia and chromosomal abnormality and also that between chromosomal abnormality and exposure to radiation. (Ueda, J.)

Fine organization of genomic regions tagged to the 5S rDNA locus of the bread wheat 5B chromosome.

Science.gov (United States)

Sergeeva, Ekaterina M; Shcherban, Andrey B; Adonina, Irina G; Nesterov, Michail A; Beletsky, Alexey V; Rakitin, Andrey L; Mardanov, Andrey V; Ravin, Nikolai V; Salina, Elena A

2017-11-14

The multigene family encoding the 5S rRNA, one of the most important structurally-functional part of the large ribosomal subunit, is an obligate component of all eukaryotic genomes. 5S rDNA has long been a favored target for cytological and phylogenetic studies due to the inherent peculiarities of its structural organization, such as the tandem arrays of repetitive units and their high interspecific divergence. The complex polyploid nature of the genome of bread wheat, Triticum aestivum, and the technically difficult task of sequencing clusters of tandem repeats mean that the detailed organization of extended genomic regions containing 5S rRNA genes remains unclear. This is despite the recent progress made in wheat genomic sequencing. Using pyrosequencing of BAC clones, in this work we studied the organization of two distinct 5S rDNA-tagged regions of the 5BS chromosome of bread wheat. Three BAC-clones containing 5S rDNA were identified in the 5BS chromosome-specific BAC-library of Triticum aestivum. Using the results of pyrosequencing and assembling, we obtained six 5S rDNA- containing contigs with a total length of 140,417 bp, and two sets (pools) of individual 5S rDNA sequences belonging to separate, but closely located genomic regions on the 5BS chromosome. Both regions are characterized by the presence of approximately 70-80 copies of 5S rDNA, however, they are completely different in their structural organization. The first region contained highly diverged short-type 5S rDNA units that were disrupted by multiple insertions of transposable elements. The second region contained the more conserved long-type 5S rDNA, organized as a single tandem array. FISH using probes specific to both 5S rDNA unit types showed differences in the distribution and intensity of signals on the chromosomes of polyploid wheat species and their diploid progenitors. A detailed structural organization of two closely located 5S rDNA-tagged genomic regions on the 5BS chromosome of bread

Molecular organization and chromosomal localization of 5S rDNA in Amazonian Engystomops (Anura, Leiuperidae).

Science.gov (United States)

Rodrigues, Débora Silva; Rivera, Miryan; Lourenço, Luciana Bolsoni

2012-03-20

For anurans, knowledge of 5S rDNA is scarce. For Engystomops species, chromosomal homeologies are difficult to recognize due to the high level of inter- and intraspecific cytogenetic variation. In an attempt to better compare the karyotypes of the Amazonian species Engystomops freibergi and Engystomops petersi, and to extend the knowledge of 5S rDNA organization in anurans, the 5S rDNA sequences of Amazonian Engystomops species were isolated, characterized, and mapped. Two types of 5S rDNA, which were readily differentiated by their NTS (non-transcribed spacer) sizes and compositions, were isolated from specimens of E. freibergi from Brazil and E. petersi from two Ecuadorian localities (Puyo and Yasuní). In the E. freibergi karyotypes, the entire type I 5S rDNA repeating unit hybridized to the pericentromeric region of 3p, whereas the entire type II 5S rDNA repeating unit mapped to the distal region of 6q, suggesting a differential localization of these sequences. The type I NTS probe clearly detected the 3p pericentromeric region in the karyotypes of E. freibergi and E. petersi from Puyo and the 5p pericentromeric region in the karyotype of E. petersi from Yasuní, but no distal or interstitial signals were observed. Interestingly, this probe also detected many centromeric regions in the three karyotypes, suggesting the presence of a satellite DNA family derived from 5S rDNA. The type II NTS probe detected only distal 6q regions in the three karyotypes, corroborating the differential distribution of the two types of 5S rDNA. Because the 5S rDNA types found in Engystomops are related to those of Physalaemus with respect to their nucleotide sequences and chromosomal locations, their origin likely preceded the evolutionary divergence of these genera. In addition, our data indicated homeology between Chromosome 5 in E. petersi from Yasuní and Chromosomes 3 in E. freibergi and E. petersi from Puyo. In addition, the chromosomal location of the type II 5S r

Macrophage-induced cytostasis: kinetic analysis of bromodeoxyuridine-pulsed cells

International Nuclear Information System (INIS)

Stevenson, A.P.; Crissman, H.A.; Stewart, C.C.

1985-01-01

The effect of tumoricidal macrophages on the cell cycle progression of six different cell lines was studied using an anti-bromodeoxyuridine (BrdUrd) monoclonal antibody to follow the traverse of BrdUrd-labeled cells. Exponentially growing cultured mammalian cells, from six different cell lines, were prepulsed with BrdUrd before exposure to tumoricidal macrophages. The cultured cells were then analyzed as a function of time for DNA content (by propidium iodide staining) and for BrdUrd incorporation (using a fluoresceini-sothiocyanate [FITC]-conjugated anti-BrdUrd monoclonal antibody). The position of the cells in cycle and the progression of the BrdUrd-labeled cohort was followed using flow cytometry. The cell lines examined were: Colon 26; BALB/c-3T3, ST3T3 (a spontaneously transformed, tumorigenic clone of 3T3), WCHE5 (a clone of whole Chinese hamster embryo cells), RIF (a radiation-induced fibrosarcoma), and A101D (a human melanoma). The bivariate distributions showed that for all six cell lines the BrdUrd-labeled cohort in the control cultures progressed around the cell cycle during the first 12 h of culture, as the cells exponentially increased. In contrast, when each cell line was incubated with tumoricidal macrophages, the BrdUrd-labeled cohort did not progress through cell cycle but remained in S phase throughout the 12-h culture period. There was also no evidence for progression of cells out of G 1 . The data show that cells were arrested in every phase of cell cycle. This study suggests that cytostasis, as manifested by the termination of progression in all phases of the cell cycle, is a universal phenomenon induced by tumoricidal macrophages. 20 references, 4 figures

Continuous intravenous infusions of bromodeoxyuridine as a clinical radiosensitizer

International Nuclear Information System (INIS)

Kinsella, T.J.; Mitchell, J.B.; Russo, A.; Aiken, M.; Morstyn, G.; Hsu, S.M.; Rowland, J.; Glatstein, E.

1984-01-01

Twelve patients were treated with continuous intravenous (24-hour) infusions of bromodeoxyuridine (BUdR) at 650 or 1000 mg/m2/d for up to two weeks. Myelosuppression, especially thrombocytopenia, was the major systemic toxicity and limited the infusion period to nine to 14 days. However, bone marrow recovery occurred within seven to ten days, allowing for a second infusion in most patients. Local toxicity (within the radiation field) was minimal, with the exception of one of four patients, who underwent abdominal irradiation. Pharmacology studies revealed a steady-state arterial plasma level of 6 x 10(-7) mol/L and 1 x 10(-6) mol/L during infusion of 650 and 1000 mg/m2/d, respectively. In vivo BUdR uptake into normal bone marrow was evaluated in two patients by comparison of preinfusion and postinfusion in vitro radiation survival curves of marrow CFUc with enhancement ratios (D0-pre/D0-post) of 1.8 (with 650 mg/m2/d) and 2.5 (with 1000 mg/m2/d). In vivo BUdR incorporation into normal skin and tumor cells using an anti-BUdR monoclonal antibody and immunohistochemistry was demonstrated in biopsies from three patients revealing substantially less cellular incorporation into normal skin (less than 10%) compared with tumor (up to 50% to 70%). The authors conclude that local and systemic toxicity of continuous infusion of BUdR at 1000 mg/m2/d for approximately two weeks is tolerable. The observed normal tissue toxicity is comparable with previous clinical experience with intermittent (12 hours every day for two weeks) infusions of BUdR. Theoretically, a constant infusion should allow for greater incorporation of BUdR into cycling tumor cells and thus, for further enhancement of radiosensitization

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

Plantago lagopus B Chromosome Is Enriched in 5S rDNA-Derived Satellite DNA

Czech Academy of Sciences Publication Activity Database

Kumke, K.; Macas, Jiří; Fuchs, J.; Altschmied, L.; Kour, J.; Dhar, M.K.; Houben, A.

2016-01-01

Roč. 148, č. 1 (2016), s. 68-73 ISSN 1424-8581 R&D Projects: GA ČR GBP501/12/G090 Institutional support: RVO:60077344 Keywords : Polymorhpic A chromosome segment * Satellite repeat * Supernumerary chromosome * 5S rDNA Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.354, year: 2016

Aneuploids of wheat and chromosomal localization of genes

African Journals Online (AJOL)

Administrator

2011-06-22

Jun 22, 2011 ... chromosome location of such genes is critical for effective utilization and subsequent manipulation. Further, chromosomal localization will lead to the identification of ... Various cytogenetic stocks and techniques have been previously reported useful in localizing genes on wheat chromosomes. The objective ...

E. S. R. studies of halogenated pyrimidines in. gamma. -irradiated alkaline glasses. [Halogenated uracil bases; bromouridine; bromodeoxyuridine

Energy Technology Data Exchange (ETDEWEB)

Simpson, L D; Zimbrick, J D [Kansas Univ., Lawrence (USA)

1975-11-01

The reactions of mobile electrons (e/sup -//sub m/) and oxygen radical anions (O./sup -/) with halogenated bases and nucleosides have been studied in ..gamma..-irradiated alkaline glasses by e.s.r. and specific halogen-ion electrode techniques. It was shown that electrons react with halogenated uracil bases (XUr where X = Cl, Br, I but not F) by dissociative electron attachment to form uracil-5-yl radicals (U.) and halogen anions. The relative rates of reaction of e/sup -//sub m/ with XUr decreased in the sequence BrUr > ClUr > FUr > IUr. Thermal annealing studies carried out on U. in H/sub 2/O and D/sub 2/O matrices supported the hypothesis that U. in H/sub 2/O hydrates across the 5-6 double bond in the temperature region 135/sup 0/ to 155/sup 0/ K, and deuterates to a much smaller extent in D/sub 2/O at temperatures above 155/sup 0/ K. Studies on bromouridine and bromodeoxyuridine suggested that e/sup -/sub(m) reacts with the base moieties to form U. type radicals which abstract H. from the sugar moieties of adjacent nucleosides.

Mosaic maternal uniparental disomy of chromosome 15 in Prader-Willi syndrome: utility of genome-wide SNP array.

Science.gov (United States)

Izumi, Kosuke; Santani, Avni B; Deardorff, Matthew A; Feret, Holly A; Tischler, Tanya; Thiel, Brian D; Mulchandani, Surabhi; Stolle, Catherine A; Spinner, Nancy B; Zackai, Elaine H; Conlin, Laura K

2013-01-01

Prader-Willi syndrome is caused by the loss of paternal gene expression on 15q11.2-q13.2, and one of the mechanisms resulting in Prader-Willi syndrome phenotype is maternal uniparental disomy of chromosome 15. Various mechanisms including trisomy rescue, monosomy rescue, and post fertilization errors can lead to uniparental disomy, and its mechanism can be inferred from the pattern of uniparental hetero and isodisomy. Detection of a mosaic cell line provides a unique opportunity to understand the mechanism of uniparental disomy; however, mosaic uniparental disomy is a rare finding in patients with Prader-Willi syndrome. We report on two infants with Prader-Willi syndrome caused by mosaic maternal uniparental disomy 15. Patient 1 has mosaic uniparental isodisomy of the entire chromosome 15, and Patient 2 has mosaic uniparental mixed iso/heterodisomy 15. Genome-wide single-nucleotide polymorphism array was able to demonstrate the presence of chromosomally normal cell line in the Patient 1 and trisomic cell line in Patient 2, and provide the evidence that post-fertilization error and trisomy rescue as a mechanism of uniparental disomy in each case, respectively. Given its ability of detecting small percent mosaicism as well as its capability of identifying the loss of heterozygosity of chromosomal regions, genome-wide single-nucleotide polymorphism array should be utilized as an adjunct to the standard methylation analysis in the evaluation of Prader-Willi syndrome. Copyright © 2012 Wiley Periodicals, Inc.

Resolving complex chromosome structures during meiosis: versatile deployment of Smc5/6

NARCIS (Netherlands)

Verver, Dideke E.; Hwang, Grace H.; Jordan, Philip W.; Hamer, Geert

2016-01-01

The Smc5/6 complex, along with cohesin and condensin, is a member of the structural maintenance of chromosome (SMC) family, large ring-like protein complexes that are essential for chromatin structure and function. Thanks to numerous studies of the mitotic cell cycle, Smc5/6 has been implicated to

Karyotype characterization of Crotalaria juncea (L. by chromosome banding and physical mapping of 18S-5.8S-26S and 5S rRNA gene sites

Directory of Open Access Journals (Sweden)

Mateus Mondin

2007-01-01

Full Text Available The chromosomes of Crotalaria juncea, a legume of agronomic interest with a 2n = 16 karyotype composed of metacentric chromosomes, were analyzed using several cytogenetic techniques. C-banding revealed heterochromatic regions around the centromeres in all chromosomes and adjacent to the secondary constriction on the chromosome 1 short arm. Fluorescent staining with the GC-specific chromomycin A3 (CMA highlighted these heterochromatic regions and a tiny site on the chromosome 1 long arm while the AT-specific stain 4'-6-diamidino-2-phenylindole (DAPI induced a reversed pattern. Staining with CMA combined with AT-specific distamycin A (DA counterstaining quenched the pericentromeric regions of all chromosomes, but enhanced fluorescence was observed at the heterochromatic regions around the secondary constriction and on the long arms of chromosomes 1 and 4. Fluorescence in situ hybridization (FISH revealed 18S-5.8S-26S rRNA gene sites (45S rDNA on chromosomes 1 and 4, and one 5S rDNA locus on chromosome 1. All the rDNA sites were co-located with the positive-CMA/DA bands, suggesting they were very rich in GC. Silver staining revealed signals at the main 45S rDNA locus on chromosome 1 and, in some cells, chromosome 4 was labeled. Two small nucleoli were detected in a few interphase cells, suggesting that the minor site on chromosome 4 could be active at some stages of the cell cycle.

Resolving complex chromosome structures during meiosis: versatile deployment of Smc5/6.

Science.gov (United States)

Verver, Dideke E; Hwang, Grace H; Jordan, Philip W; Hamer, Geert

2016-03-01

The Smc5/6 complex, along with cohesin and condensin, is a member of the structural maintenance of chromosome (SMC) family, large ring-like protein complexes that are essential for chromatin structure and function. Thanks to numerous studies of the mitotic cell cycle, Smc5/6 has been implicated to have roles in homologous recombination, restart of stalled replication forks, maintenance of ribosomal DNA (rDNA) and heterochromatin, telomerase-independent telomere elongation, and regulation of chromosome topology. The nature of these functions implies that the Smc5/6 complex also contributes to the profound chromatin changes, including meiotic recombination, that characterize meiosis. Only recently, studies in diverse model organisms have focused on the potential meiotic roles of the Smc5/6 complex. Indeed, Smc5/6 appears to be essential for meiotic recombination. However, due to both the complexity of the process of meiosis and the versatility of the Smc5/6 complex, many additional meiotic functions have been described. In this review, we provide a clear overview of the multiple functions found so far for the Smc5/6 complex in meiosis. Additionally, we compare these meiotic functions with the known mitotic functions in an attempt to find a common denominator and thereby create clarity in the field of Smc5/6 research.

Persistence of chromosomal abnormalities additional to the Philadelphia chromosome after Philadelphia chromosome disappearance during imatinib therapy for chronic myeloid leukemia.

Science.gov (United States)

Zaccaria, Alfonso; Valenti, Anna Maria; Donti, Emilio; Gozzetti, Alessandro; Ronconi, Sonia; Spedicato, Francesco

2007-04-01

Five Philadelphia chromosome positive (Ph+) chronic myeloid leukemia (CML) patients with additional chromosome abnormalities at diagnosis have been followed during Imatinib therapy. In all, the Ph chromosome disappeared, while the 5 cases, additional abnormalities [dup(1); del(5), +8 (2 patients) and +14] persisted in the subsequent studies, performed over a period of 11 to 49 months, either alone or together with a karyotypically normal cell population. This finding is consistent with a secondary origin of the Ph chromosome in these patients. It is still to early to evaluate the possible prognostic value of these additional abnormalities.

Wagner vitreoretinal degeneration with genetic linkage refinement on chromosome 5q13-q14.

Science.gov (United States)

Zech, J C; Morlé, L; Vincent, P; Alloisio, N; Bozon, M; Gonnet, C; Milazzo, S; Grange, J D; Trepsat, C; Godet, J; Plauchu, H

1999-05-01

It has been previously described that Wagner disease is linked to chromosome 5q13-q14. This study was carried out to describe the ophthalmological aspects and report the results of genetic linkage analysis in a large pedigree affected by Wagner disease. Fourty members of one same family agreed to be examined. Twenty patients presented vitreoretinal degeneration in both eyes without any extra-ocular abnormalities. In young patients, visual acuity was usually normal after correction of frequent mild myopia. Presenile cataracts progressed by the third decade and required removal for visual rehabilitation. The primary disorder involved an abnormal vitreous. A few avascular vitreous bands were usually the only optical feature in the mostly empty vitreous cavity. A circumferential vitreous condensation formed in contact with the retina on many spots. Less common retinal findings included retinal detachment, abnormal retinal pigmentation, progressive atrophy of the RPE simulating choroideremia and lattice degeneration. Genetic analysis revealed a highly significant linkage (lod score >5.0) between the disease and 10 markers of the chromosome 5q13-q14 region. Two recombination events allowed us to refine the linked interval to 20 cM between the D5S650 and D5S618 markers. Ophthalmological aspects of Wagner's disease appear to progress with age. Regular ophthalmological examination is important for detecting retinal abnormalities. The gene involved in Wagner's disease lies in a 20 cM interval on chromosome 5q13-q14.

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

Ultraviolet and chemical induced DNA repair in human cells assayed by bromodeoxyuridine photolysis or cytosine arabinoside arrest

International Nuclear Information System (INIS)

Regan, J.D.; Dunn, W.C.

1979-01-01

The bromodeoxyuridine photolysis assay of DNA damage in human cells permits an estimate of both the number of repaired regions in the DNA and the size of the average repaired region - the patch size. The antineoplastic agent arabinofuranosyl cytosine (ara-C) can also be employed to assay the magnitude of repair since this agent appears to block rejoining of single-strand incisions made in the DNA during the initial step of repair. Thus, the number of incisions can be accumulated. The ara-C effect is dependent on the presence of hydroxyurea. Both assays can be employed for the study of physical or chemical DNA damages. Results comparing these assays are presented

Chromosomally Encoded mcr-5 in Colistin non-susceptible Pseudomonas aeruginosa.

Science.gov (United States)

Snesrud, Erik; Maybank, Rosslyn; Kwak, Yoon I; Jones, Anthony R; Hinkle, Mary K; Mc Gann, Patrick

2018-05-29

Whole genome sequencing (WGS) of historical Pseudomonas aeruginosa clinical isolates identified a chromosomal copy of mcr-5 within a Tn 3 -like transposon in P. aeruginosa MRSN 12280. The isolate was non-susceptible to colistin by broth microdilution and genome analysis revealed no mutations known to confer colistin resistance. To the best of our knowledge, this is the first report of mcr in colistin non-susceptible P. aeruginosa .

Acción de la 5'azacitidina en cromosomas de células linfocitarias de bovinos 5'azacytidine effect in bovine lymphocytes chromosomes

Directory of Open Access Journals (Sweden)

Silvia Llambí

2008-01-01

Full Text Available La azacitidina (5-azaC es una sustancia que actúa inhibiendo la metilación del ADN, es utilizada en experiencias de clonación, transgénesis por transferencia nuclear y estudios de fragilidad cromosómica. Se ha observado la manifestación de diversas patologías en animales domésticos nacidos de experiencias de clonación. Ellas estarían asociadas a una inexacta reprogramación nuclear relacionada con fenómenos epigenéticos de metilación del ADN. En el presente trabajo se realizó una curva de inducción con diferentes concentraciones finales de 5-azaC (0 uM, 5 uM, 10 uM, 20 uM, 50 uM y 70 uM con el objetivo de estudiar los efectos sobre la estructura cromosómica en cultivos linfocitarios bovinos. Se utilizó la técnica de macrocultivo para análisis cromosómico a partir de sangre de un bovino macho (Bos taurus, Holstein Friesian. Se analizó un total de 50 placas metafásicas por tubo de cultivo y se encontraron diferencias significativas (pAzacytidine (5-azaC is a substance that inhibits the metilation of DNA, being used in cloning experiments, nuclear transference transgenesis and in chromosomal fragility studies. The manifestation of diverse pathologies has been observed in domestic animals born from cloning experiments. These would be associated to an incorrect nuclear reprogramation related to epigenetic metilation phenomena of the DNA. In the present work an induction curve with different final concentrations of 5-azaC (0 uM, 5 uM, 10 uM, 20 uM, 50 uM and 70 uM were carried out, with the objective of studying the effects on chromosome structure in bovine lymphocyte cultures. The macroculture technique was used for chromosomic analysis, from a blood sample of a male bovine (Bos taurus, Holstein Friesian. A total of 50 metaphases were analyzed from each culture. Significative differences (p<0.01 were found regarding the break points of chromosome X in the control culture with respect to the culture with higher concentration of 5

Mapping of 5q35 chromosomal rearrangements within a genomically unstable region

DEFF Research Database (Denmark)

Buysse, Karen; Crepel, An; Menten, Björn

2008-01-01

these rearrangements. METHODS: We analysed a series of patients with breakpoints clustering within chromosome band 5q35. Using high density arrays and subsequent quantitative polymerase chain reaction (qPCR), we characterised the breakpoints of four interstitial deletions (including one associated with an unbalanced...

Modeling Chromosomes

Science.gov (United States)

Robertson, Carol

2016-01-01

Learning about chromosomes is standard fare in biology classrooms today. However, students may find it difficult to understand the relationships among the "genome", "chromosomes", "genes", a "gene locus", and "alleles". In the simple activity described in this article, which follows the 5E approach…

Clinical Utility of Array Comparative Genomic Hybridization for Detection of Chromosomal Abnormalities in Pediatric Acute Lymphoblastic Leukemia

Science.gov (United States)

Rabin, Karen R.; Man, Tsz-Kwong; Yu, Alexander; Folsom, Matthew R.; Zhao, Yi-Jue; Rao, Pulivarthi H.; Plon, Sharon E.; Naeem, Rizwan C.

2014-01-01

Background Accurate detection of recurrent chromosomal abnormalities is critical to assign patients to risk-based therapeutic regimens for pediatric acute lymphoblastic leukemia (ALL). Procedure We investigated the utility of array comparative genomic hybridization (aCGH) for detection of chromosomal abnormalities compared to standard clinical evaluation with karyotype and fluorescent in-situ hybridization (FISH). Fifty pediatric ALL diagnostic bone marrows were analyzed by bacterial artificial chromosome (BAC) array, and findings compared to standard clinical evaluation. Results Sensitivity of aCGH was 79% to detect karyotypic findings other than balanced translocations, which cannot be detected by aCGH because they involve no copy number change. aCGH also missed abnormalities occurring in subclones constituting less than 25% of cells. aCGH detected 44 additional abnormalities undetected or misidentified by karyotype, 21 subsequently validated by FISH, including abnormalities in 4 of 10 cases with uninformative cytogenetics. aCGH detected concurrent terminal deletions of both 9p and 20q in three cases, in two of which the 20q deletion was undetected by karyotype. A narrow region of loss at 7p21 was detected in two cases. Conclusions An array with increased BAC density over regions important in ALL, combined with PCR for fusion products of balanced translocations, could minimize labor- and time-intensive cytogenetic assays and provide key prognostic information in the approximately 35% of cases with uninformative cytogenetics. PMID:18253961

Cerebellar and brainstem hypoplasia in a child with a partial monosomy for the short arm of chromosome 5 and partial trisomy for the short arm of chromosome 10

NARCIS (Netherlands)

Arts, W F M; Hofstee, Y; Drejer, G F; Beverstock, G C; Oosterwijk, J C

A child with hypoplasia of the cerebellum and brainstem in association with an unbalanced translocation, resulting in a partial deletion of the short arm of chromosome 5 and a partial trisomy of the short arm of chromosome 10, is described. A balanced translocation was present in his mother and

The incidence of chromosome abnormalities in neonates with structural heart disease.

Science.gov (United States)

Dykes, John C; Al-mousily, Mohammad F; Abuchaibe, Eda-Cristina; Silva, Jennifer N; Zadinsky, Jennifer; Duarte, Daniel; Welch, Elizabeth

2016-04-01

This study was conducted to determine the prevalence of chromosomal anomalies in newborns with structural heart disease admitted to the cardiac intensive care unit (CICU) at Nicklaus Children's Hospital (NCH). A retrospective review identified newborns age 30 days or less admitted to NCH CICU between 2004 and 2010. Patients with structural heart disease who required admission to our CICU and received karyotype or karyotype and fluorescent in situ hybridization (FISH) testing were included in the study. All patients were examined for the presence of dysmorphic features. Four hundred and eighty-two patients met the criteria for the study; 405 (84%) received both karyotype and FISH. Chromosome abnormalities were present in 86 (17.8%) patients. Syndromes accounted for 20 (5.1%) of those with normal chromosomes. Dysmorphic features were seen in 79.1% of patients with abnormal chromosomes and 25.5% of those with normal chromosomes. All patients with syndromes were dysmorphic. Race and gender did not significantly affect the incidence of genetic abnormalities. Chromosome abnormalities, including syndromes, are prevalent in newborns with congenital heart disease. Further research is needed to evaluate the utility of cytogenetic screening in all children with congenital heart disease. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

An Overview on Prenatal Screening for Chromosomal Aberrations.

Science.gov (United States)

Hixson, Lucas; Goel, Srishti; Schuber, Paul; Faltas, Vanessa; Lee, Jessica; Narayakkadan, Anjali; Leung, Ho; Osborne, Jim

2015-10-01

This article is a review of current and emerging methods used for prenatal detection of chromosomal aneuploidies. Chromosomal anomalies in the developing fetus can occur in any pregnancy and lead to death prior to or shortly after birth or to costly lifelong disabilities. Early detection of fetal chromosomal aneuploidies, an atypical number of certain chromosomes, can help parents evaluate their pregnancy options. Current diagnostic methods include maternal serum sampling or nuchal translucency testing, which are minimally invasive diagnostics, but lack sensitivity and specificity. The gold standard, karyotyping, requires amniocentesis or chorionic villus sampling, which are highly invasive and can cause abortions. In addition, many of these methods have long turnaround times, which can cause anxiety in mothers. Next-generation sequencing of fetal DNA in maternal blood enables minimally invasive, sensitive, and reasonably rapid analysis of fetal chromosomal anomalies and can be of clinical utility to parents. This review covers traditional methods and next-generation sequencing techniques for diagnosing aneuploidies in terms of clinical utility, technological characteristics, and market potential. © 2015 Society for Laboratory Automation and Screening.

Chromosome identification by new molecular markers and genomic in situ hybridization in the Triticum-Secale-Thinopyrum trigeneric hybrids.

Science.gov (United States)

Dai, Yi; Duan, Yamei; Chi, Dawn; Liu, Huiping; Huang, Shuai; Cao, Wenguang; Gao, Yong; Fedak, George; Chen, Jianmin

2017-08-01

It is very important to use chromosome-specific markers for identifying alien chromosomes in advanced generations of distant hybridization. The chromosome-specific markers of rye and Thinopyrum elongatum, as well as genomic in situ hybridization, were used to identify the alien chromosomes in eight lines that were derived from the crossing between Triticum trititrigia (AABBEE) and triticale (AABBRR). The results showed that four lines contained all rye chromosomes but no Th. elongatum chromosomes. The line RE36-1 contained all of the rye chromosomes except for chromosome 2R. The lines RE33-2 and RE62-1 contained all rye chromosomes and 1E and 5E translocated chromosome, respectively. The line RE24-4 contained 12 rye chromosomes plus a 7E chromosome or 12 rye chromosomes plus one R-E translocated chromosome. Chromosome identification in the above lines was consistent using chromosome-specific markers and genomic in situ hybridization. These chromosome-specific markers provide useful tools for detecting alien chromosomes in trigeneric hybrids, and these lines could be utilized as valuable germplasm in wheat improvement.

Molecular and cytogenetic characterization of the 5DS-5BS chromosome translocation conditioning soft kernel texture in durum wheat

Science.gov (United States)

Cultivar ‘Soft Svevo’, a new non-GMO soft durum cultivar with soft kernel texture, was developed through a 5DS(5BS) chromosomal translocation from event. cv. Chinese Spring, and subsequently used to create new soft durum germplasm. The development of Soft Svevo featured the Ph1b-mediated homoeologou...

24 CFR 5.632 - Utility reimbursements.

Science.gov (United States)

2010-04-01

... Section 8 Project-Based Assistance Family Payment § 5.632 Utility reimbursements. (a) Applicability. This... the utility supplier to pay the utility bill on behalf of the family. If the PHA elects to pay the utility supplier, the PHA must notify the family of the amount paid to the utility supplier. (3) In the...

Non-Random Distribution of 5S rDNA Sites and Its Association with 45S rDNA in Plant Chromosomes.

Science.gov (United States)

Roa, Fernando; Guerra, Marcelo

2015-01-01

5S and 45S rDNA sites are the best mapped chromosome regions in eukaryotic chromosomes. In this work, a database was built gathering information about the position and number of 5S rDNA sites in 784 plant species, aiming to identify patterns of distribution along the chromosomes and its correlation with the position of 45S rDNA sites. Data revealed that in most karyotypes (54.5%, including polyploids) two 5S rDNA sites (a single pair) are present, with 58.7% of all sites occurring in the short arm, mainly in the proximal region. In karyotypes of angiosperms with only 1 pair of sites (single sites) they are mostly found in the proximal region (52.0%), whereas in karyotypes with multiple sites the location varies according to the average chromosome size. Karyotypes with multiple sites and small chromosomes (6 µm) more commonly show terminal or interstitial sites. In species with holokinetic chromosomes, the modal value of sites per karyotype was also 2, but they were found mainly in a terminal position. Adjacent 5S and 45S rDNA sites were often found in the short arm, reflecting the preferential distribution of both sites in this arm. The high frequency of genera with at least 1 species with adjacent 5S and 45S sites reveals that this association appeared several times during angiosperm evolution, but it has been maintained only rarely as the dominant array in plant genera. © 2015 S. Karger AG, Basel.

Chromosomal homologies among vampire bats revealed by chromosome painting (phyllostomidae, chiroptera).

Science.gov (United States)

Sotero-Caio, C G; Pieczarka, J C; Nagamachi, C Y; Gomes, A J B; Lira, T C; O'Brien, P C M; Ferguson-Smith, M A; Souza, M J; Santos, N

2011-01-01

Substantial effort has been made to elucidate karyotypic evolution of phyllostomid bats, mostly through comparisons of G-banding patterns. However, due to the limited number of G-bands in respective karyotypes and to the similarity of non-homologous bands, an accurate evolutionary history of chromosome segments remains questionable. This is the case for vampire bats (Desmodontinae). Despite several proposed homologies, banding data have not yet provided a detailed understanding of the chromosomal changes within vampire genera. We examined karyotype differentiation of the 3 species within this subfamily using whole chromosomal probes from Phyllostomus hastatus (Phyllostominae) and Carollia brevicauda (Carolliinae). Painting probes of P. hastatus respectively detected 22, 21 and 23 conserved segments in Diphylla ecaudata, Diaemus youngi, and Desmodus rotundus karyotypes, whereas 27, 27 and 28 were respectively detectedwith C. brevicauda paints. Based on the evolutionary relationships proposed by morphological and molecular data, we present probable chromosomal synapomorphies for vampire bats and propose chromosomes that were present in the common ancestor of the 5 genera analyzed. Karyotype comparisons allowed us to relate a number of conserved chromosomal segments among the 5 species, providing a broader database for understanding karyotype evolution in the family. 2010 S. Karger AG, Basel.

Tritiated uracil, tritiated thymidine, and bromodeoxyuridine induced mutations in eucaryotic cells

International Nuclear Information System (INIS)

Burki, H.J.; Moustacchi, E.; Cleaver, J.E.

1979-02-01

The induction of gene conversion at the ARG-4 locus in strain BZ34 of Saccharomyces cerevisiae was examined after the cells incorporated y- 3 H uracil under optimum growth conditions for 16 hours, and then received damage at 4 0 C from tritium decays at very low dose rates of 1.4 to 27.6 tritium decays per hour. The results were compared to the results of gene conversion induced by 60 Co. The induction of resistance to 6TG in Chinese hamster ovary (CHO) cells has been studied after incorporation of 3 H-methyl thymidine, 6- 3 H-thymidine, and bromodeoxyuridine under several experimental conditions. The induction of mutations by incorporated 6- 3 H-thymidine is about three times as effective as the induction of mutations by tritiated-methyl thymidine. These results suggest that the determination of the RBE for tritium decays in model eucaryotic systems like yeast and cultured Chinese hamster cells will be influenced by the precise experimental conditions employed. In particular, experiments with mammalian cells will be affected by hot times for mutagenesis in the cell cycle and hot positions within the DNA in the nucleus, and also by the position of tritium decay within the DNA-incorporated molecule

SMC5/6 is required for the formation of segregation-competent bivalent chromosomes during meiosis I in mouse oocytes.

Science.gov (United States)

Hwang, Grace; Sun, Fengyun; O'Brien, Marilyn; Eppig, John J; Handel, Mary Ann; Jordan, Philip W

2017-05-01

SMC complexes include three major classes: cohesin, condensin and SMC5/6. However, the localization pattern and genetic requirements for the SMC5/6 complex during mammalian oogenesis have not previously been examined. In mouse oocytes, the SMC5/6 complex is enriched at the pericentromeric heterochromatin, and also localizes along chromosome arms during meiosis. The infertility phenotypes of females with a Zp3-Cre -driven conditional knockout (cKO) of Smc5 demonstrated that maternally expressed SMC5 protein is essential for early embryogenesis. Interestingly, protein levels of SMC5/6 complex components in oocytes decline as wild-type females age. When SMC5/6 complexes were completely absent in oocytes during meiotic resumption, homologous chromosomes failed to segregate accurately during meiosis I. Despite what appears to be an inability to resolve concatenation between chromosomes during meiosis, localization of topoisomerase IIα to bivalents was not affected; however, localization of condensin along the chromosome axes was perturbed. Taken together, these data demonstrate that the SMC5/6 complex is essential for the formation of segregation-competent bivalents during meiosis I, and findings suggest that age-dependent depletion of the SMC5/6 complex in oocytes could contribute to increased incidence of oocyte aneuploidy and spontaneous abortion in aging females. © 2017. Published by The Company of Biologists Ltd.

Long-range epigenetic silencing of chromosome 5q31 protocadherins is involved in early and late stages of colorectal tumorigenesis through modulation of oncogenic pathways

DEFF Research Database (Denmark)

Dallosso, A R; Øster, Bodil; Greenhough, A

2012-01-01

Loss of tumour suppressor gene function can occur as a result of epigenetic silencing of large chromosomal regions, referred to as long-range epigenetic silencing (LRES), and genome-wide analyses have revealed that LRES is present in many cancer types. Here we utilize Illumina Beadchip methylation...... array analysis to identify LRES across 800 kb of chromosome 5q31 in colorectal adenomas and carcinomas (n=34) relative to normal colonic epithelial DNA (n=6). This region encompasses 53 individual protocadherin (PCDH) genes divided among three gene clusters. Hypermethylation within these gene clusters......–polymerase chain reaction showed that PCDHGC3 is the highest expressed PCDH in normal colonic epithelium, and that there was a strong reciprocal relationship between PCDHGC3 methylation and expression in carcinomas (R=−0.84). PCDH LRES patterns are reflected in colorectal tumour cell lines; adenoma cell lines...

The Utility of Lymphocyte Premature Chromosome Condensation Analysis for Biological Dosimetry Following Accidental Overexposure to Ionising Radiation

International Nuclear Information System (INIS)

Chambrette, V.; Laval, F.; Voisin, P.

1999-01-01

Premature chromosome condensation (PCC) appears to have a possible utility for biological dosimetry purposes. The PCC technique may be adapted for cases of suspicion of overexposure where sampling is performed at least one day after an accident. For this purpose, human blood samples were exposed in vitro to 60 Co (0.5 Gy.min -1 ) up to 4 Gy and the PCC technique was performed after 24 h, 48 h, and 72 h of DNA repair at 37 deg. C. Analysis of excess PCC fragments distribution showed an overdispersion and the dose-effect relationship was best characterised by linear regression. Radiation-induced damage was reduced to 32% between the first and the second day of repair and to 42% the following day. Statistical precision of the dose was found to be dependent on the irradiation dose and on the number of cells examined. The necessity to establish dose-response relationships after different periods of DNA repair is demonstrated, and the use of PCC excess fragments yield as a bioindicator should take this fact into account. (author)

Chromosomal Locations of 5S and 45S rDNA in Gossypium Genus and Its Phylogenetic Implications Revealed by FISH.

Science.gov (United States)

Gan, Yimei; Liu, Fang; Chen, Dan; Wu, Qiong; Qin, Qin; Wang, Chunying; Li, Shaohui; Zhang, Xiangdi; Wang, Yuhong; Wang, Kunbo

2013-01-01

We investigated the locations of 5S and 45S rDNA in Gossypium diploid A, B, D, E, F, G genomes and tetraploid genome (AD) using multi-probe fluorescent in situ hybridization (FISH) for evolution analysis in Gossypium genus. The rDNA numbers and sizes, and synteny relationships between 5S and 45S were revealed using 5S and 45S as double-probe for all species, and the rDNA-bearing chromosomes were identified for A, D and AD genomes with one more probe that is single-chromosome-specific BAC clone from G. hirsutum (A1D1). Two to four 45S and one 5S loci were found in diploid-species except two 5S loci in G. incanum (E4), the same as that in tetraploid species. The 45S on the 7th and 9th chromosomes and the 5S on the 9th chromosomes seemed to be conserved in A, D and AD genomes. In the species of B, E, F and G genomes, the rDNA numbers, sizes, and synteny relationships were first reported in this paper. The rDNA pattern agrees with previously reported phylogenetic history with some disagreements. Combined with the whole-genome sequencing data from G. raimondii (D5) and the conserved cotton karyotype, it is suggested that the expansion, decrease and transposition of rDNA other than chromosome rearrangements might occur during the Gossypium evolution.

Prevention of 5-fluorouracil-caused growth inhibition in Sordaria fimicola.

Science.gov (United States)

Schoen, H F; Berech, J

1977-02-01

Growth (dry weight accumulation) of Sordaria fimicola in standing liquid culture (sucrose-nitrate-salts-vitamins) is inhibited by the presence of 5 muM 5-fluorouracil in the medium. This inhibition is completely prevented by uracil, deoxyuridine, and 5-bromouracil, partly prevented (40 to 90% of growth observed without 5-fluorouracil) by uridine, thymidine, and 5-bromodeoxyuridine, and slightly prevented by trifluorothymine, cytosine, cytidine, deoxycytidine, and 5-methylcytosine (all at 0.5 to 1 mM). Thymidine and thymine riboside were without any apparent effect. Growth is also inhibited by 0.2 mM 6-azauracil, and this inhibition was completely prevented by uracil and uridine, partly prevented by deoxyuridine, 5-bromouracil, cytidine, and 5-methylcytosine, and slightly prevented by thymine, thymidine, 5-bromodeoxyuridine, cytosine, and deoxycytidine. The data suggest that the observed inhibition of growth by 5-fluorouracil is due to inhibition of both ribonucleic acid and deoxyribonucleic acid synthesis. The data also allow inferences concerning pyrimidine interconversions in S. fimicola; i.e., thymine can be anabolized to thymidylic acid without first being demethylated, although demethylation appears to occur also.

Molecular mapping of chromosomes 17 and X

Energy Technology Data Exchange (ETDEWEB)

Barker, D.F.

1991-01-15

Progress toward the construction of high density genetic maps of chromosomes 17 and X has been made by isolating and characterizing a relatively large set of polymorphic probes for each chromosome and using these probes to construct genetic maps. We have mapped the same polymorphic probes against a series of chromosome breakpoints on X and 17. The probes could be assigned to over 30 physical intervals on the X chromosome and 7 intervals on 17. In many cases, this process resulted in improved characterization of the relative locations of the breakpoints with respect to each other and the definition of new physical intervals. The strategy for isolation of the polymorphic clones utilized chromosome specific libraries of 1--15 kb segments from each of the two chromosomes. From these libraries, clones were screened for those detecting restriction fragment length polymorphisms. The markers were further characterized, the chromosomal assignments confirmed and in most cases segments of the original probes were subcloned into plasmids to produce probes with improved signal to noise ratios for use in the genetic marker studies. The linkage studies utilize the CEPH reference families and other well-characterized families in our collection which have been used for genetic disease linkage work. Preliminary maps and maps of portions of specific regions of 17 and X are provided. We have nearly completed a map of the 1 megabase Mycoplasma arthritidis genome by applying these techniques to a lambda phage library of its genome. We have found bit mapping to be an efficient means to organize a contiguous set of overlapping clones from a larger genome.

Assignment of CSF-1 to 5q33.1: evidence for clustering of genes regulating hematopoiesis and for their involvement in the deletion of the long arm of chromosome 5 in myeloid disorders

International Nuclear Information System (INIS)

Pettenati, M.J.; Le Beau, M.M.; Lemons, R.S.; Shima, E.A.; Kawasaki, E.S.; Larson, R.A.; Sherr, C.J.; Diaz, M.O.; Rowley, J.D.

1987-01-01

The CSF-1 gene encodes a hematopoietic colony-stimulating factor (CSF) that promotes growth, differentiation, and survival of mononuclear phagocytes. By using somatic cell hybrids and in situ hybridization, the authors localized this gene to human chromosome 5 at bands q31 to q35, a chromosomal region that is frequently deleted [del(5q)] in patients with myeloid disorders. By in situ hybridization, the CSF-1 gene was found to be deleted in the 5q- chromosome of a patient with refractory anemia who had a del(5) (q15q33.3) and in that of a second patient with acute nonlymphocytic leukemia de novo who had a similar distal breakpoint [del(5)(q13q33.3)]. The gene was present in the deleted chromosome of a third patient, with therapy-related acute nonlymphocytic leukemia, who had a more proximal breakpoint in band q33 [del(5)(q22q33.1)]. Hybridization of the CSF-1 probe to metaphase cells of a fourth patient, with acute nonlymphocytic leukemia de novo, who had a rearrangement of chromosomes 5 and 21 resulted in labeling of the breakpoint junctions of both rearranged chromosomes; this suggested that CSF-1 is located at 5q33.1. Thus, a small segment of chromosome 5 contains GM-CSF (the gene encoding the granulocyte-macrophage CSF), CSF-1, and FMS, which encodes the CSF-1 receptor, in that order from the centromere; this cluster of genes may be involved in the altered hematopoiesis associated with a deletion of 5q

[THE INFLUENCE OF THE PREPARATION PRETREATMENT ON IN SITU DETECTION OF 5-METHYLCYTOSINE IN METAPHASE CHROMOSOMES AND IN INTERPHASE NUCLEI].

Science.gov (United States)

Grudinina, N A; Sasina, L K; Noniashvili, E M; Neronova, E G; Pavlinova, L I; Suchkova, I O; Sofronov, G A; Patkin, E L

2015-01-01

Qualitative and quantitate analysis of DNA methylation in situ at the level of cells, chromosomes and chromosomal domains is extremely important for the diagnosis and treatment of various diseases, the study of ageing and the consequences of environmental impacts. An important question arises, whether the revealed in situ methylation pattern reflects DNA methylation per se and (or) availability of the DNA for antibodies, which in turn depends on the peculiarities of chromatin structure and chromosome condensation. These events can lead to an incorrect evaluation of the actual pattern of DNA methylation. To avoid this shortcoming as far as possible, we have modified the most widely used method of revealing 5-methylcytosine in situ with monoclonal antibodies. Here we have shown that the detection of DNA methylation staining of chromosomes including C-heterochromatin, chromosomal arms and sister chromatids is drastically dependent on pretreatment of chromosomal preparations for immunocytochemical study using fluorescent antibodies. Using undifferentiated stem cells of mouse embryonal carcinoma line F9, it has been found that change in preparations storage results in a sharp fluorescence decrease up to complete disappearance of the signal in centromeric heterochromatin. With the help of the method described in the work, we have first revealed the asymmetry of sister chromatids methylation in metaphase chromosomes of F9 cell and lymphocytes of human periphery blood. This may lead to asymmetry of transcriptional signature of daughter cells after division. The proposed here modification of 5-methylcytosine detection in situ provides a more complete characterization of methylation of chromosomes and chromosomal domains, compared to previously published methods.

The SMC-5/6 Complex and the HIM-6 (BLM Helicase Synergistically Promote Meiotic Recombination Intermediate Processing and Chromosome Maturation during Caenorhabditis elegans Meiosis.

Directory of Open Access Journals (Sweden)

Ye Hong

2016-03-01

Full Text Available Meiotic recombination is essential for the repair of programmed double strand breaks (DSBs to generate crossovers (COs during meiosis. The efficient processing of meiotic recombination intermediates not only needs various resolvases but also requires proper meiotic chromosome structure. The Smc5/6 complex belongs to the structural maintenance of chromosome (SMC family and is closely related to cohesin and condensin. Although the Smc5/6 complex has been implicated in the processing of recombination intermediates during meiosis, it is not known how Smc5/6 controls meiotic DSB repair. Here, using Caenorhabditis elegans we show that the SMC-5/6 complex acts synergistically with HIM-6, an ortholog of the human Bloom syndrome helicase (BLM during meiotic recombination. The concerted action of the SMC-5/6 complex and HIM-6 is important for processing recombination intermediates, CO regulation and bivalent maturation. Careful examination of meiotic chromosomal morphology reveals an accumulation of inter-chromosomal bridges in smc-5; him-6 double mutants, leading to compromised chromosome segregation during meiotic cell divisions. Interestingly, we found that the lethality of smc-5; him-6 can be rescued by loss of the conserved BRCA1 ortholog BRC-1. Furthermore, the combined deletion of smc-5 and him-6 leads to an irregular distribution of condensin and to chromosome decondensation defects reminiscent of condensin depletion. Lethality conferred by condensin depletion can also be rescued by BRC-1 depletion. Our results suggest that SMC-5/6 and HIM-6 can synergistically regulate recombination intermediate metabolism and suppress ectopic recombination by controlling chromosome architecture during meiosis.

The SMC-5/6 Complex and the HIM-6 (BLM) Helicase Synergistically Promote Meiotic Recombination Intermediate Processing and Chromosome Maturation during Caenorhabditis elegans Meiosis.

Science.gov (United States)

Hong, Ye; Sonneville, Remi; Agostinho, Ana; Meier, Bettina; Wang, Bin; Blow, J Julian; Gartner, Anton

2016-03-01

Meiotic recombination is essential for the repair of programmed double strand breaks (DSBs) to generate crossovers (COs) during meiosis. The efficient processing of meiotic recombination intermediates not only needs various resolvases but also requires proper meiotic chromosome structure. The Smc5/6 complex belongs to the structural maintenance of chromosome (SMC) family and is closely related to cohesin and condensin. Although the Smc5/6 complex has been implicated in the processing of recombination intermediates during meiosis, it is not known how Smc5/6 controls meiotic DSB repair. Here, using Caenorhabditis elegans we show that the SMC-5/6 complex acts synergistically with HIM-6, an ortholog of the human Bloom syndrome helicase (BLM) during meiotic recombination. The concerted action of the SMC-5/6 complex and HIM-6 is important for processing recombination intermediates, CO regulation and bivalent maturation. Careful examination of meiotic chromosomal morphology reveals an accumulation of inter-chromosomal bridges in smc-5; him-6 double mutants, leading to compromised chromosome segregation during meiotic cell divisions. Interestingly, we found that the lethality of smc-5; him-6 can be rescued by loss of the conserved BRCA1 ortholog BRC-1. Furthermore, the combined deletion of smc-5 and him-6 leads to an irregular distribution of condensin and to chromosome decondensation defects reminiscent of condensin depletion. Lethality conferred by condensin depletion can also be rescued by BRC-1 depletion. Our results suggest that SMC-5/6 and HIM-6 can synergistically regulate recombination intermediate metabolism and suppress ectopic recombination by controlling chromosome architecture during meiosis.

Comparative chromosomal localization of 45S and 5S rDNAs and implications for genome evolution in Cucumis.

Science.gov (United States)

Zhang, Zhen-Tao; Yang, Shu-Qiong; Li, Zi-Ang; Zhang, Yun-Xia; Wang, Yun-Zhu; Cheng, Chun-Yan; Li, Ji; Chen, Jin-Feng; Lou, Qun-Feng

2016-07-01

Ribosomal DNAs are useful cytogenetic markers for chromosome analysis. Studies investigating site numbers and distributions of rDNAs have provided important information for elucidating genome organization and chromosomal relationships of many species by fluorescence in situ hybridization. But relevant studies are scarce for species of the genus Cucumis, especially in wild species. In the present study, FISH was conducted to investigate the organization of 45S and 5S rDNA among 20 Cucumis accessions, including cultivars and wild accessions. Our results showed that the number of 45S rDNA sites varied from one to five pairs in different accessions, and most of these sites are located at the terminal regions of chromosomes. Interestingly, up to five pairs of 45S rDNA sites were observed in C. sativus var. sativus, the species which has the lowest chromosome number, i.e., 2n = 14. Only one pair of 5S rDNA sites was detected in all accessions, except for C. heptadactylus, C. sp, and C. spp that had two pairs of 5S rDNA sites. The distributions of 5S rDNA sites showed more variation than 45S rDNA sites. The phylogenetic analysis in this study showed that 45S and 5S rDNA have contrasting evolutionary patterns. We find that 5S rDNA has a polyploidization-related tendency towards the terminal location from an interstitial location but maintains a conserved site number, whereas the 45S rDNA showed a trend of increasing site number but a relatively conserved location.

In situ hybridization of iodinated 5S and 18/25S RNA to Vicia faba metaphase chromosomes

International Nuclear Information System (INIS)

Schubert, I.; Baeumlein, H.; Wobus, U.

1978-01-01

In vitro labelled 125 I ribosomal RNA fractions (18/25S and 5S) were in situ hybridized to metaphase chromosomes of a reconstructed karyotype of Vicia faba (characterized by two translocations and one pericentric inversion, each being present homozygously). The sites of 18S and 25S RNA were found to be confined to the nucleolus organizing secondary constriction. Two loci of 5S RNA were recognized on the satellite of nucleolus bearing chromosome. Possible correlations between the location of ribosomal genes, heterochromatic G-bands and clusters of mutagen induced chromatid aberrations are discussed. (author)

Destabilized SMC5/6 complex leads to chromosome breakage syndrome with severe lung disease

NARCIS (Netherlands)

van der Crabben, Saskia N; Hennus, Marije P; McGregor, Grant A; Ritter, Deborah I; Nagamani, Sandesh C S; Wells, Owen S; Harakalova, Magdalena; Chinn, Ivan K; Alt, Aaron; Vondrova, Lucie; Hochstenbach, Ron; van Montfrans, Joris M; Terheggen-Lagro, Suzanne W; van Lieshout, Stef; van Roosmalen, Markus J; Renkens, Ivo; Duran, Karen; Nijman, Isaäc J.; Kloosterman, Wigard P; Hennekam, Eric; Orange, Jordan S; van Hasselt, Peter M; Wheeler, David A; Palecek, Jan J; Lehmann, Alan R; Oliver, Antony W; Pearl, Laurence H; Plon, Sharon E; Murray, Johanne M; van Haaften, Gijs

The structural maintenance of chromosomes (SMC) family of proteins supports mitotic proliferation, meiosis, and DNA repair to control genomic stability. Impairments in chromosome maintenance are linked to rare chromosome breakage disorders. Here, we have identified a chromosome breakage syndrome

Utilization of deletion bins to anchor and order sequences along the wheat 7B chromosome.

Science.gov (United States)

Belova, Tatiana; Grønvold, Lars; Kumar, Ajay; Kianian, Shahryar; He, Xinyao; Lillemo, Morten; Springer, Nathan M; Lien, Sigbjørn; Olsen, Odd-Arne; Sandve, Simen R

2014-09-01

A total of 3,671 sequence contigs and scaffolds were mapped to deletion bins on wheat chromosome 7B providing a foundation for developing high-resolution integrated physical map for this chromosome. Bread wheat (Triticum aestivum L.) has a large, complex and highly repetitive genome which is challenging to assemble into high quality pseudo-chromosomes. As part of the international effort to sequence the hexaploid bread wheat genome by the international wheat genome sequencing consortium (IWGSC) we are focused on assembling a reference sequence for chromosome 7B. The successful completion of the reference chromosome sequence is highly dependent on the integration of genetic and physical maps. To aid the integration of these two types of maps, we have constructed a high-density deletion bin map of chromosome 7B. Using the 270 K Nimblegen comparative genomic hybridization (CGH) array on a set of cv. Chinese spring deletion lines, a total of 3,671 sequence contigs and scaffolds (~7.8 % of chromosome 7B physical length) were mapped into nine deletion bins. Our method of genotyping deletions on chromosome 7B relied on a model-based clustering algorithm (Mclust) to accurately predict the presence or absence of a given genomic sequence in a deletion line. The bin mapping results were validated using three different approaches, viz. (a) PCR-based amplification of randomly selected bin mapped sequences (b) comparison with previously mapped ESTs and (c) comparison with a 7B genetic map developed in the present study. Validation of the bin mapping results suggested a high accuracy of the assignment of 7B sequence contigs and scaffolds to the 7B deletion bins.

Isolation of a cosmid sublibrary for a region of chromosome 12 frequently amplified in human cancers using a complex chromosome microdissection probe

Energy Technology Data Exchange (ETDEWEB)

Elkahloun, A.G.; Meltzer, P.S.; Guan, Xin-Yuan [National Institutes of Health, Bethesda, MD (United States)] [and others

1996-02-01

Chromosome-specific cosmid libraries are in extremely useful resource for positional cloning projects. Once a particular region of interest has been identified, it would be of value to have an approach for isolating chromosome band-specific cosmids that could be assembled into a sublibrary for rapid screening. We constructed a region-specific sublibrary of 700 cosmids by screening a chromosome 12-specific cosmid library with a complex probe generated by degenerate oligonucleotide-primed PCR of a microdissected homogeneously staining region containing sequences amplified from chromosome 12q13-q15. Based on fluorescence in situ hybridization, approximately 60% of the cosmids in the sublibrary were derived from the microdissected region. To demonstrate further the utility of the sublibrary, a 150-kb contig containing the SAS and CDK4 genes was constructed, as well as several additional contigs between CDK4 and MDM2. This study demonstrates the possibility of utilizing probes generated by microdissection for assembling band-specific libraries that are amendable to rapid screening with multiple markers.

High-resolution gene maps of horse chromosomes 14 and 21: additional insights into evolution and rearrangements of HSA5 homologs in mammals.

Science.gov (United States)

Goh, Glenda; Raudsepp, Terje; Durkin, Keith; Wagner, Michelle L; Schäffer, Alejandro A; Agarwala, Richa; Tozaki, Teruaki; Mickelson, James R; Chowdhary, Bhanu P

2007-01-01

High-resolution physically ordered gene maps for equine homologs of human chromosome 5 (HSA5), viz., horse chromosomes 14 and 21 (ECA14 and ECA21), were generated by adding 179 new loci (131 gene-specific and 48 microsatellites) to the existing maps of the two chromosomes. The loci were mapped primarily by genotyping on a 5000-rad horse x hamster radiation hybrid panel, of which 28 were mapped by fluorescence in situ hybridization. The approximately fivefold increase in the number of mapped markers on the two chromosomes improves the average resolution of the map to 1 marker/0.9 Mb. The improved resolution is vital for rapid chromosomal localization of traits of interest on these chromosomes and for facilitating candidate gene searches. The comparative gene mapping data on ECA14 and ECA21 finely align the chromosomes to sequence/gene maps of a range of evolutionarily distantly related species. It also demonstrates that compared to ECA14, the ECA21 segment corresponding to HSA5 is a more conserved region because of preserved gene order in a larger number of and more diverse species. Further, comparison of ECA14 and the distal three-quarters region of ECA21 with corresponding chromosomal segments in 50 species belonging to 11 mammalian orders provides a broad overview of the evolution of these segments in individual orders from the putative ancestral chromosomal configuration. Of particular interest is the identification and precise demarcation of equid/Perissodactyl-specific features that for the first time clearly distinguish the origins of ECA14 and ECA21 from similar-looking status in the Cetartiodactyls.

Influence of inhibitors of poly(ADP-ribose) polymerase on DNA repair, chromosomal alterations, and mutations

Energy Technology Data Exchange (ETDEWEB)

Natarajan, A.T.; van Zeeland, A.A.; Zwanenburg, T.S.

1983-01-01

The influence of inhibitors of poly(ADP-ribose) polymerase such as 3-aminobenzamide (3AB) and benzamide (B) on the spontaneously occurring as well as mutagen induced chromosomal aberrations, sister chromatid exchanges (SCEs) and point mutations has been studied. In addition, the influence of 3AB on DNA repair was measured following treatment with physical and chemical mutagens. Post treatment of X-irradiated mammalian cells with 3AB increases the frequencies of induced chromosomal aberrations by a factor of 2 to 3. 3AB, when present in the medium containing bromodeoxyuridine(BrdUrd) during two cell cycles, increases the frequencies of SCEs in Chinese hamster ovary cells (CHO) in a concentration dependent manner leading to about a 10-fold increase at 10 mM concentration. The extent of increase in the frequencies of SCEs due to 1 mM 3AB in several human cell lines has been studied, including those derived from patients suffering from genetic diseases such as ataxia telangiectasia (A-T), Fanconi's anemia (FA), and Huntington's chorea. None of these syndromes showed any increased response when compared to normal cells. 3AB, however, increased the frequencies of spontaneously occurring chromosomal aberrations in A-T and FA cells. 3AB does not influence the frequencies of SCEs induced by UV or mitomycin C (MMC) in CHO cells. However, it increases the frequencies of SCEs induced by ethyl methanesulfonate (EMS) and methyl methanesulfonate (MMS). Under the conditions in which 3AB increases the frequencies of spontaneously occurring as well as induced SCEs, it does not increase the frequencies of point mutations in hypoxanthine-guanine phosphoribosyltransferase (HGPRT) locus. 3AB does not influence the amount of repair replication following dimethylsulphate (DMS) treatment of human fibroblasts, or UV irradiated human lymphocytes.

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

Genetic and radiation hybrid mapping of the hyperekplexia region on chromosome 5q

Energy Technology Data Exchange (ETDEWEB)

Ryan, S.G.; O' Connell, P. (Univ. of Texas Health Science Center, San Antonio (United States)); Dixon, M.J. (Univ. of Manchester (United Kingdom)); Nigro, M.A. (Wayne State Univ., Detroit, MI (United States)); Kelts, K.A. (Black Hills Neurology, Rapid City, SD (United States)); Markand, O.N. (Indiana Univ., Indianopolis (United States)); Shiang, R.; Wasmuth, J.J. (Univ. of California, Irvine (United States)); Terry, J.C.

1992-12-01

Hyperekplexia, or startle disease (STHE), is an autosomal dominant neurologic disorder characterized by muscular rigidity of central nervous system origin, particularly in the neonatal period, and by an exaggerated startle response to sudden, unexpected acoustic or tactile stimuli. STHE responds dramatically to the benzodiazepine drug clonazepam, which acts at gamma-aminobutyric acid type A (GABA-A) receptors. The STHE locus (STHE) was recently assigned to chromosome 5q, on the basis of tight linkage to the colony-stimulating factor 1-receptor (CSF1-R) locus in a single large family. The authors performed linkage analysis in the original and three additional STHE pedigrees with eight chromosome 5q microsatellite markers and placed several of the most closely linked markers on an existing radiation hybrid (RH) map of the region. The results provide strong evidence for genetic locus homogeneity and assign STHE to a 5.9-cM interval defined by CSF1-R and D5S379, which are separated by an RH map distance of 74 centirays (roughly 2.2-3.7 Mb). Two polymorphic markers (D5S119 and D5S209) lie within this region, but they could not be ordered with respect to STHE. RH mapping eliminated the candidate genes GABRA1 and GABRG2, which encode GABA-A receptor components, by showing that they are telomeric to the target region. 45 refs., 4 figs., 4 tabs.

Paternal uniparental isodisomy of chromosome 11p15.5 within the pancreas causes isolated hyperinsulinaemic hypoglycaemia

Directory of Open Access Journals (Sweden)

Sarah E Flanagan

2011-11-01

Full Text Available BackgroundLoss of function mutations in the genes encoding the pancreatic β-cell ATP-sensitive potassium (KATP channel are identified in approximately 80% of patients with diazoxide-unresponsive hyperinsulinaemic-hypoglycaemia (HH. For a small number of patients HH can occur as part of a multisystem disease such as Beckwith-Wiedemann syndrome (BWS. In approximately 20% of patients, BWS results from chromosome 11 paternal uniparental disomy (UPD, which causes dysregulation of imprinted growth regulation genes at 11p15.5. There is a considerable range in the clinical features and phenotypic severity associated with BWS which is likely to be due to somatic mosaicism. The cause of HH in these patients is not known.Research Design and methodsWe undertook microsatellite analysis of 12 markers spanning chromosome 11p in two patients with severe HH and diffuse disease requiring a pancreatectomy. In both patients mutations in the KATP channel genes had not been identified. ResultsWe identified segmental paternal UPD in DNA extracted from pancreatic tissue in both patients. UPD was not observed in DNA extracted from the patient’s leukocytes or buccal samples. In both cases the UPD encompassed the differentially methylated region at chromosome 11p15.5. Despite this neither patient had any further features of BWS.ConclusionsPaternal UPD of the chromosome 11p15.5 differentially methylated region limited to the pancreatic tissue may represent a novel cause of isolated diazoxide unresponsive HH. Loss of heterozygosity studies should therefore be considered in all patients with severe HH who have undergone pancreatic surgery when KATP channel mutation(s have not been identified.

X-ray sensitization of chromatids with unifilarly and bifilarly substituted DNA

International Nuclear Information System (INIS)

Wolff, S.

1981-01-01

When cells are grown for two rounds of DNA replication in the presence of the thymidine analogue 5-bromodeoxyuridine, chromosomes containing one chromatid with unifilarly substituted DNA and one with bifilarly substituted DNA are found. These can be distinguished by harlequin staining techniques that stain one chromatid dark and one light. When the degree of substitution is 60% or greater, 3 times as many X-ray-induced chromatid breaks are produced as in unsubstituted chromatids. This represents maximal sensitization. The unifilarly substituted (dark) chromatid is as sensitive as its bifilarly substituted (light) sister chromatid. If cells are grown in low concentrations of 5-bromodeoxyuridine (BrdUrd), then the amount of substitution is less and the bifilarly substituted chromatic is more sensitive than the unifilarly substituted one. When large numbers of cells are grown in very low concentrations of BrdUrd, the analogue is almost completely depleted during the first round of replication leading to harlequin chromosomes containing one unsubstituted (dark) and one unifilarly substituted (light) chromatid. Under these conditions a maximal sensitization between light-staining and dark-staining chromatids can occur. This can be confused with the differential sensitivity between unifilarly and bifilarly substituted chromatids. The apparent discrepant results obtained by different investigators are most likely caused by the use of very low levels of BrdUrd in some of the experiments. (orig.)

Highly Efficient Transfer of Chromosomes to a Broad Range of Target Cells Using Chinese Hamster Ovary Cells Expressing Murine Leukemia Virus-Derived Envelope Proteins.

Directory of Open Access Journals (Sweden)

Teruhiko Suzuki

Full Text Available Microcell-mediated chromosome transfer (MMCT is an essential step for introducing chromosomes from donor cells to recipient cells. MMCT allows not only for genetic/epigenetic analysis of specific chromosomes, but also for utilization of human and mouse artificial chromosomes (HACs/MACs as gene delivery vectors. Although the scientific demand for genome scale analyses is increasing, the poor transfer efficiency of the current method has hampered the application of chromosome engineering technology. Here, we developed a highly efficient chromosome transfer method, called retro-MMCT, which is based on Chinese hamster ovary cells expressing envelope proteins derived from ecotropic or amphotropic murine leukemia viruses. Using this method, we transferred MACs to NIH3T3 cells with 26.5 times greater efficiency than that obtained using the conventional MMCT method. Retro-MMCT was applicable to a variety of recipient cells, including embryonic stem cells. Moreover, retro-MMCT enabled efficient transfer of MAC to recipient cells derived from humans, monkeys, mice, rats, and rabbits. These results demonstrate the utility of retro-MMCT for the efficient transfer of chromosomes to various types of target cell.

Chromosome behaviour in Rhoeo spathacea var. variegata.

Science.gov (United States)

Lin, Y J

1980-01-01

Rhoeo spathacea var. variegata is unusual in that its twelve chromosomes are arranged in a ring at meiosis. The order of the chromosomes has been established, and each chromosome arm has been designated a letter in accordance with the segmental interchange theory. Chromosomes are often irregularly orientated at metaphase I. Chromosomes at anaphase I are generally distributed equally (6-6, 58.75%) although not necessarily balanced. Due to adjacent distribution, 7-5 distribution at anaphase I was frequently observed (24.17%), and due to lagging, 6-1-5 and 5-2-5 distributions were also observed (10.83% and 3.33% respectively). Three types of abnormal distribution, 8-4, 7-1-4 and 6-2-4 were observed very infrequently (2.92% total), and their possible origins are discussed. Irregularities, such as adjacent distribution and lagging, undoubtedly reduce the fertility of the plant because of the resulting unbalanced gametes.

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...

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 ...

5-bp Classical Satellite DNA Loci from Chromosome-1 Instability in Cervical Neoplasia Detected by DNA Breakage Detection/Fluorescence in Situ Hybridization (DBD-FISH

Directory of Open Access Journals (Sweden)

Jaime Gosálvez

2013-02-01

Full Text Available We aimed to evaluate the association between the progressive stages of cervical neoplasia and DNA damage in 5-bp classical satellite DNA sequences from chromosome-1 in cervical epithelium and in peripheral blood lymphocytes using DNA breakage detection/fluorescence in situ hybridization (DBD-FISH. A hospital-based unmatched case-control study was conducted in 2011 with a sample of 30 women grouped according to disease stage and selected according to histological diagnosis; 10 with low-grade squamous intraepithelial lesions (LG-SIL, 10 with high-grade SIL (HG-SIL, and 10 with no cervical lesions, from the Unidad Medica de Alta Especialidad of The Mexican Social Security Institute, IMSS, Mexico. Specific chromosome damage levels in 5-bp classical satellite DNA sequences from chromosome-1 were evaluated in cervical epithelium and peripheral blood lymphocytes using the DBD-FISH technique. Whole-genome DNA hybridization was used as a reference for the level of damage. Results of Kruskal-Wallis test showed a significant increase according to neoplastic development in both tissues. The instability of 5-bp classical satellite DNA sequences from chromosome-1 was evidenced using chromosome-orientation FISH. In conclusion, we suggest that the progression to malignant transformation involves an increase in the instability of 5-bp classical satellite DNA sequences from chromosome-1.

5-bp Classical Satellite DNA Loci from Chromosome-1 Instability in Cervical Neoplasia Detected by DNA Breakage Detection/Fluorescence in Situ Hybridization (DBD-FISH).

Science.gov (United States)

Cortés-Gutiérrez, Elva I; Ortíz-Hernández, Brenda L; Dávila-Rodríguez, Martha I; Cerda-Flores, Ricardo M; Fernández, José Luis; López-Fernández, Carmen; Gosálvez, Jaime

2013-02-19

We aimed to evaluate the association between the progressive stages of cervical neoplasia and DNA damage in 5-bp classical satellite DNA sequences from chromosome-1 in cervical epithelium and in peripheral blood lymphocytes using DNA breakage detection/fluorescence in situ hybridization (DBD-FISH). A hospital-based unmatched case-control study was conducted in 2011 with a sample of 30 women grouped according to disease stage and selected according to histological diagnosis; 10 with low-grade squamous intraepithelial lesions (LG-SIL), 10 with high-grade SIL (HG-SIL), and 10 with no cervical lesions, from the Unidad Medica de Alta Especialidad of The Mexican Social Security Institute, IMSS, Mexico. Specific chromosome damage levels in 5-bp classical satellite DNA sequences from chromosome-1 were evaluated in cervical epithelium and peripheral blood lymphocytes using the DBD-FISH technique. Whole-genome DNA hybridization was used as a reference for the level of damage. Results of Kruskal-Wallis test showed a significant increase according to neoplastic development in both tissues. The instability of 5-bp classical satellite DNA sequences from chromosome-1 was evidenced using chromosome-orientation FISH. In conclusion, we suggest that the progression to malignant transformation involves an increase in the instability of 5-bp classical satellite DNA sequences from chromosome-1.

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

Molecular mapping of chromosomes 17 and X. Progress report

Energy Technology Data Exchange (ETDEWEB)

Barker, D.F.

1991-01-15

Progress toward the construction of high density genetic maps of chromosomes 17 and X has been made by isolating and characterizing a relatively large set of polymorphic probes for each chromosome and using these probes to construct genetic maps. We have mapped the same polymorphic probes against a series of chromosome breakpoints on X and 17. The probes could be assigned to over 30 physical intervals on the X chromosome and 7 intervals on 17. In many cases, this process resulted in improved characterization of the relative locations of the breakpoints with respect to each other and the definition of new physical intervals. The strategy for isolation of the polymorphic clones utilized chromosome specific libraries of 1--15 kb segments from each of the two chromosomes. From these libraries, clones were screened for those detecting restriction fragment length polymorphisms. The markers were further characterized, the chromosomal assignments confirmed and in most cases segments of the original probes were subcloned into plasmids to produce probes with improved signal to noise ratios for use in the genetic marker studies. The linkage studies utilize the CEPH reference families and other well-characterized families in our collection which have been used for genetic disease linkage work. Preliminary maps and maps of portions of specific regions of 17 and X are provided. We have nearly completed a map of the 1 megabase Mycoplasma arthritidis genome by applying these techniques to a lambda phage library of its genome. We have found bit mapping to be an efficient means to organize a contiguous set of overlapping@ clones from a larger genome.

Production of alien chromosome additions and their utility in plant genetics

NARCIS (Netherlands)

Chang, S.B.; Jong, de J.H.S.G.M.

2005-01-01

Breeding programs aiming at transferring desirable genes from one species to another through interspecific hybridization and backcrossings often produce monosomic and disomic additions as intermediate crossing products. Such aneuploids contain alien chromosomes added to the complements of the

Chromosomal aberrations in bone marrow of continuously irradiated rats

Energy Technology Data Exchange (ETDEWEB)

Chlebosky, O; Praslicka, M; Chlebovska, K [Univerzita P.J. Safarika, Kosice (Czechoslovakia). Prirodovedecka Fakulta

1975-01-01

Research on chromosomal aberrations of the bone marrow in continuously irradiated rats showed that chromosomal aberrations are a highly sensitive indicator of radiation injury. An increase in the chromosomal aberration frequency was already found on the 5th day at daily doses of 0.5 R, i.e. a 12% increase at a total dose of 25 R. In the steady-state stage at daily doses of 0.5; 1; 2.5 R, the number of chromosomal aberrations stabilized at values of about 20%; at daily doses of 5 and 10 R at values of 30.=., at daily doses of 53 R at 45%, at a daily dose of 82.5 R, the number of chromosomal aberrations increased to 55%.

An improved method for chromosome counting in maize.

Science.gov (United States)

Kato, A

1997-09-01

An improved method for counting chromosomes in maize (Zea mays L.) is presented. Application of cold treatment (5C, 24 hr), heat treatment (42 C, 5 min) and a second cold treatment (5C, 24 hr) to root tips before fixation increased the number of condensed and dispersed countable metaphase chromosome figures. Fixed root tips were prepared by the enzymatic maceration-air drying method and preparations were stained with acetic orcein. Under favorable conditions, one preparation with 50-100 countable chromosome figures could be obtained in diploid maize using this method. Conditions affecting the dispersion of the chromosomes are described. This technique is especially useful for determining the somatic chromosome number in triploid and tetraploid maize lines.

Chromosome reduction in Eleocharis maculosa (Cyperaceae).

Science.gov (United States)

da Silva, C R M; González-Elizondo, M S; Laforga Vanzela, A L

2008-01-01

Chromosome numbers in Cyperaceae lower than the typical basic number x = 5 have been described for only three species: Rhynchospora tenuis (n = 2), Fimbristylis umbellaris (n = 3) and Eleocharis subarticulata (n = 3). Eleocharis maculosa is recorded here as the fourth species of Cyperaceae that has a chromosome number lower than 2n = 10, with 2n = 8, 7 and 6. The karyotype differentiation in E. maculosa was studied using conventional staining (mitosis and meiosis), FISH with 45S and 5S rDNA and telomere probes. The results allow us to determine which chromosomes of the chromosome race with 2n = 10 fused to form the remaining reduced numbers, as well as to understand how the symploidy and translocation mechanisms were important in karyotype differentiation and the formation of chromosome races in Eleocharis. Copyright 2008 S. Karger AG, Basel.

Appearance and evolution of the specific chromosomal rearrangements associated with malignant transformation of mouse m5S cells

International Nuclear Information System (INIS)

Kodama, S.; Okumura, Y.; Komatsu, K.; Sasaki, M.S.

1991-01-01

Chromosomal alterations were studied during the acquisition of malignant phenotypes in two karyotypically distinct cells isolated from transformed foci induced by x-irradiation in mouse m5S cells. Because the transformants, despite foci origin, showed low ability to grow in agar, they were cultured in vitro with serial transfer schedules to allow further cell generations and assayed for anchorage independence (AI) at each passage level. The AI frequency increased with the cell doubling numbers. Chromosome analysis showed that a focus was one cell origin, but the transformants showed karyotypic instability during cell proliferation, giving rise to the rearrangements clustered in the distal region of the specific chromosomes. These rearrangements appeared to be directed toward the acquisition of malignant phenotypes. Analysis of the types and sites of rearrangements indicated that a mechanism exists that induces frequent rearrangements of the specific region of a chromosome during the process of transformation into the malignant state

Elimination of nonspecific radioactivity from [76Br]bromide in PET study with [76Br]bromodeoxyuridine

International Nuclear Information System (INIS)

Li Lu; Bergstroem, Mats; Fasth, Karl-Johan; Wu Feng; Eriksson, Barbro; Laangstroem, Bengt

1999-01-01

[ 76 Br]Bromodeoxyuridine ([ 76 Br]BrdU) might allow a determination of proliferation in vivo using positron emission tomography (PET), but only with consideration of organ nonspecific radioactivity constituted by [ 76 Br]bromide. A first study assessed the potential of diuretics to eliminate [ 76 Br]bromide. [ 76 Br]Bromide was injected in the vein of rats and different diuretic combinations were given. Urine was collected and radioactivity measured. Torasemide plus sodium chloride gave better 76 Br elimination than the other diuretics. In a second experiment, rats were given [ 76 Br]BrdU. After the radioactivity injection, the rats of the treatment group were given torasemide plus NaCl. At 44 h after the radioactivity injection, the radioactivity concentration and the fraction incorporated into DNA were measured in different organs. Using diuretics, the elimination of [ 76 Br]bromide was increased. The radioactivity decreased 30-50% in most of the organs but the highest radioactivity uptake was found in the organs with more active DNA synthesis. This method may facilitate the use of [ 76 Br]BrdU as a tracer for DNA synthesis using PET

Microdissection and molecular manipulation of single chromosomes in woody fruit trees with small chromosomes using pomelo (Citrus grandis) as a model. I. Construction of single chromosomal DNA libraries.

Science.gov (United States)

Huang, D; Wu, W; Zhou, Y; Hu, Z; Lu, L

2004-05-01

Construction of single chromosomal DNA libraries by means of chromosome microdissection and microcloning will be useful for genomic research, especially for those species that have not been extensively studied genetically. Application of the technology of microdissection and microcloning to woody fruit plants has not been reported hitherto, largely due to the generally small sizes of metaphase chromosomes and the difficulty of chromosome preparation. The present study was performed to establish a method for single chromosome microdissection and microcloning in woody fruit species using pomelo as a model. The standard karyotype of a pomelo cultivar ( Citrus grandis cv. Guanxi) was established based on 20 prometaphase photomicrographs. According to the standard karyotype, chromosome 1 was identified and isolated with fine glass microneedles controlled by a micromanipulator. DNA fragments ranging from 0.3 kb to 2 kb were acquired from the isolated single chromosome 1 via two rounds of PCR mediated by Sau3A linker adaptors and then cloned into T-easy vectors to generate a DNA library of chromosome 1. Approximately 30,000 recombinant clones were obtained. Evaluation based on 108 randomly selected clones showed that the sizes of the cloned inserts varied from 0.5 kb to 1.5 kb with an average of 860 bp. Our research suggests that microdissection and microcloning of single small chromosomes in woody plants is feasible.

Chromosomal mapping of H3 histone and 5S rRNA genes in eight species of Astyanax (Pisces, Characiformes) with different diploid numbers: syntenic conservation of repetitive genes.

Science.gov (United States)

Piscor, Diovani; Parise-Maltempi, Patricia Pasquali

2016-03-01

The genus Astyanax is widely distributed from the southern United States to northern Patagonia, Argentina. While cytogenetic studies have been performed for this genus, little is known about the histone gene families. The aim of this study was to examine the chromosomal relationships among the different species of Astyanax. The chromosomal locations of the 5S rRNA and H3 histone genes were determined in A. abramis, A. asuncionensis, A. altiparanae, A. bockmanni, A. eigenmanniorum, A. mexicanus (all 2n = 50), A. fasciatus (2n = 46), and A. schubarti (2n = 36). All eight species exhibited H3 histone clusters on two chromosome pairs. In six species (A. abramis, A. asuncionensis, A. altiparanae, A. bockmanni, A. eigenmanniorum, and A. fasciatus), syntenic clusters of H3 histone and 5S rDNA were observed on metacentric (m) or submetacentric (sm) chromosomes. In seven species, clusters of 5S rDNA sequences were located on one or two chromosome pairs. In A. mexicanus, 5S rDNA clusters were located on four chromosome pairs. This study demonstrates that H3 histone clusters are conserved on two chromosome pairs in the genus Astyanax, and specific chromosomal features may contribute to the genomic organization of the H3 histone and 5S rRNA genes.

Chromosomal instability and double minute chromosomes in a breast cancer patient

International Nuclear Information System (INIS)

Lalic, H.; Radosevic-Stasic, B.

2004-01-01

Cytogenetic analysis was performed in peripheral blood lymphocytes (PBL) of a woman with ductal breast carcinoma, who as a hospital employee was exposed professionally for 15 years to low doses of ionizing radiation. The most important finding after the chemotherapy in combination with radiotherapy was the presence of double minutes (DM) chromosomes, in combination with other chromosomal abnormalities (on 200 scored metaphases were found 2 chromatid breaks, 10 dicentrics, 11 acentric fragments, 2 gaps, and 3 double min chromosomes). In a repeated analysis (after 6 months), DM chromosomes were still present. To rule out the possibility that the patient was overexposed to ionizing radiation at work, her blood test was compared with a group of coworkers as well as with a group of professionally unexposed people. The data rejected this possibility, but the retroactive analysis showed that the patient even at the time of employment had a moderately increased number of chromosomal aberrations (3.5%) consisting of 3 isochromatids and 4 gaps, suggesting that her initial genomic instability enhanced the later development. The finding of a continuous presence of rare DM chromosomes in her PBL (4 and 10 months after radio-chemotherapy) was considered as an indicator of additional risk, which might have some prognostic significance. (author)

Fine genetic structure of the 2D3-2F5 region of the X-chromosome of Drosophila melanogaster

International Nuclear Information System (INIS)

Gvozdev, V.A.; Gostimsky, S.A.; Gerasimova, T.I.; Dubrovskaya, E.S.; Braslavskaya, O.Yu.

1975-01-01

97 lethal and semilethal mutations were induced by ethyl methanesulfonate, nitrosomethyl urea and γ-irradiation in the 2D3-F5 region of the X-chromosome of D. melanogaster. Approximately 1 per cent of the tested X-chromosomes carried a lethal in the 2D3-2F5 region. The mutation frequencies per band of DNA content in this region and the whole X-chromosome are equal. Complementation analysis revealed at least 10 functionally independent essential loci in this region including about 10 bands. The data presented in this study support the one band - one gene hypothesis. The Pgd locus coding for 6-phosphogluconate dehydrogenase (6PGD) is mapped in the 2D3 (or 2D4) band. Isolation of 11 lethal or semilethal point mutations with null or reduced 6PGD acticity shows that the Pgd locus is a vital one. (orig.) [de

The Utility of Chromosomal Microarray Analysis in Developmental and Behavioral Pediatrics

Science.gov (United States)

Beaudet, Arthur L.

2013-01-01

Chromosomal microarray analysis (CMA) has emerged as a powerful new tool to identify genomic abnormalities associated with a wide range of developmental disabilities including congenital malformations, cognitive impairment, and behavioral abnormalities. CMA includes array comparative genomic hybridization (CGH) and single nucleotide polymorphism…

Development of T. aestivum L.-H. californicum alien chromosome lines and assignment of homoeologous groups of Hordeum californicum chromosomes.

Science.gov (United States)

Fang, Yuhui; Yuan, Jingya; Wang, Zhangjun; Wang, Haiyan; Xiao, Jin; Yang, Zhixi; Zhang, Ruiqi; Qi, Zengjun; Xu, Weigang; Hu, Lin; Wang, Xiu-E

2014-08-20

Hordeum californicum (2n = 2x = 14, HH) is resistant to several wheat diseases and tolerant to lower nitrogen. In this study, a molecular karyotype of H. californicum chromosomes in the Triticum aestivum L. cv. Chinese Spring (CS)-H. californicum amphidiploid (2n = 6x = 56, AABBDDHH) was established. By genomic in situ hybridization (GISH) and multicolor fluorescent in situ hybridization (FISH) using repetitive DNA clones (pTa71, pTa794 and pSc119.2) as probes, the H. californicum chromosomes could be differentiated from each other and from the wheat chromosomes unequivocally. Based on molecular karyotype and marker analyses, 12 wheat-alien chromosome lines, including four disomic addition lines (DAH1, DAH3, DAH5 and DAH6), five telosomic addition lines (MtH7L, MtH1S, MtH1L, DtH6S and DtH6L), one multiple addition line involving H. californicum chromosome H2, one disomic substitution line (DSH4) and one translocation line (TH7S/1BL), were identified from the progenies derived from the crosses of CS-H. californicum amphidiploid with common wheat varieties. A total of 482 EST (expressed sequence tag) or SSR (simple sequence repeat) markers specific for individual H. californicum chromosomes were identified, and 47, 50, 45, 49, 21, 51 and 40 markers were assigned to chromosomes H1, H2, H3, H4, H5, H6 and H7, respectively. According to the chromosome allocation of these markers, chromosomes H2, H3, H4, H5, and H7 of H. californicum have relationship with wheat homoeologous groups 5, 2, 6, 3, and 1, and hence could be designated as 5H(c), 2H(c), 6H(c), 3H(c) and 1H(c), respectively. The chromosomes H1 and H6 were designated as 7H(c) and 4H(c), respectively, by referring to SSR markers located on rye chromosomes. Copyright © 2014 Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, and Genetics Society of China. Published by Elsevier Ltd. All rights reserved.

Coupling amplified DNA from flow-sorted chromosomes to high-density SNP mapping in barley

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Bartoš Jan

2008-06-01

Full Text Available Abstract Background Flow cytometry facilitates sorting of single chromosomes and chromosome arms which can be used for targeted genome analysis. However, the recovery of microgram amounts of DNA needed for some assays requires sorting of millions of chromosomes which is laborious and time consuming. Yet, many genomic applications such as development of genetic maps or physical mapping do not require large DNA fragments. In such cases time-consuming de novo sorting can be minimized by utilizing whole-genome amplification. Results Here we report a protocol optimized in barley including amplification of DNA from only ten thousand chromosomes, which can be isolated in less than one hour. Flow-sorted chromosomes were treated with proteinase K and amplified using Phi29 multiple displacement amplification (MDA. Overnight amplification in a 20-microlitre reaction produced 3.7 – 5.7 micrograms DNA with a majority of products between 5 and 30 kb. To determine the purity of sorted fractions and potential amplification bias we used quantitative PCR for specific genes on each chromosome. To extend the analysis to a whole genome level we performed an oligonucleotide pool assay (OPA for interrogation of 1524 loci, of which 1153 loci had known genetic map positions. Analysis of unamplified genomic DNA of barley cv. Akcent using this OPA resulted in 1426 markers with present calls. Comparison with three replicates of amplified genomic DNA revealed >99% concordance. DNA samples from amplified chromosome 1H and a fraction containing chromosomes 2H – 7H were examined. In addition to loci with known map positions, 349 loci with unknown map positions were included. Based on this analysis 40 new loci were mapped to 1H. Conclusion The results indicate a significant potential of using this approach for physical mapping. Moreover, the study showed that multiple displacement amplification of flow-sorted chromosomes is highly efficient and representative which

UTILIZATION OF 5Es' CONSTRUCTIVIST APPROACH FOR ...

African Journals Online (AJOL)

Global Journal

learning, the effective utilization of which can enhance biology teaching and learning. This paper focused on how ... KEYWORDS: Utilization, 5Es Constructivist approach, difficult concepts, Biology. ... gives hope to the development of the deep.

Phenotypic consequences of a mosaic marker chromosome identified by fluorescence in situ hybridization (FISH) as being derived from chromosome 16

Energy Technology Data Exchange (ETDEWEB)

Ray, J.H.; Zhou, X.; Pletcher, B.A. [Cornell Univ. Medical College, Manhasset, NY (United States)] [and others

1994-09-01

De novo marker chromosomes are detected in 1 in 2500 amniotic fluid samples and are associated with a 10-15% risk for phenotypic abnormality. FISH can be utilized as a research tool to identify the origins of marker chromosomes. The phenotypic consequences of a marker chromosome derived from the short arm of chromosome 16 are described. A 26-year-old woman underwent amniocentesis at 28 weeks gestation because of a prenatally diagnosed tetralogy of Fallot. Follow-up ultrasounds also showed ventriculomegaly and cleft lip and palate. 32 of 45 cells had the karyotype 47,XY,+mar; the remaining cells were 46,XY. The de novo marker chromosome was C-band positive and non-satellited and failed to stain with distamycin A/DAPI. At birth the ultrasound findings were confirmed and dysmorphic features and cryptorchidism were noted. Although a newborn blood sample contained only normal cells, mosaicism was confirmed in 2 skin biopsies. FISH using whole-chromosome painting and alpha-satellite DNA probes showed that the marker chromosome had originated from chromosome 16. As proximal 16q is distamycin A/DAPI positive, the marker is apparently derived from proximal 16p. At 15 months of age, this child is hypotonic, globally delayed and is gavage-fed. His physical examination is significant for microbrachycephaly, a round face, sparse scalp hair, ocular hypertelorism, exotropia, a flat, wide nasal bridge and tip, mild micrognathia, and tapered fingers with lymphedema of hands and feet. Inguinal hernias have been repaired. His features are consistent with those described for patients trisomic for most or all of the short arm of chromosome 16. Marker chromosomes derived from the short arm of chromosome 16 appear to have phenotypic consequences. As the origin of more marker chromosomes are identified using FISH, their karyotype/phenotype correlations will become more apparent, which will permit more accurate genetic counseling.

Linkage group-chromosome correlations in Sordaria macrospora: Chromosome identification by three dimensional reconstruction of their synaptonemal complex.

Science.gov (United States)

Zickler, D; Leblon, G; Haedens, V; Collard, A; Thuriaux, P

1984-01-01

Reconstruction of serially sectioned zygotene and pachytene nuclei has allowed, by measuring the lengths of synaptonemal complexes, an assignment of the 7 linkage (LG) groups to the 7 chromosomes in the fungus Sordaria macrospora. The 7 LG have been established using 19 mutants showing low second division segregation frequencies. Eight chromosomal rearrangements mapped on the 7 LG were used to identify the chromosomes involved. The following one to one assignment of the 7 LG to specific chromosomes was obtained: LG a: chromosome (chr) 1, LG b: chr5, LG c: chr6, LG d: chr7, LG e: chr4, LG f: chr3 and LG g: chr2 (the chromosome carrying the nucleolus organizer region).

Gonadal sex chromosome complement in individuals with sex chromosomal and/or gonadal disorders

Energy Technology Data Exchange (ETDEWEB)

Bridge, J.A.; Sanger, W.G.; Seemayer, T. [Univ. of Nebraska Medical Center, Omaha, NE (United States)] [and others

1994-09-01

Gonadal abnormalities are characteristically seen in patients with sex chromosomal aneuploidy. Morphologically these abnormalities can be variable and are hypothesized to be dependent on the sex chromosomal consititution of the gonad (independent of the chromosomal complement of other tissues, such as peripheral blood lymphocytes). In this study, the gonadal sex chromosome complement was evaluated for potential mosaicism and correlated with the histopathology from 5 patients with known sex chromosomal and/or gonadal disorders. FISH techniques using X and Y chromosome specific probes were performed on nuclei extracted from paraffin embedded tissue. Gonadal tissue obtained from case 1 (a true hemaphroditic newborn) consisted of ovotestes and epididymis (left side) and ovary with fallopian tube (right side). Cytogenetic and FISH studies performed on blood, ovotestes and ovary revealed an XX complement. Cytogenetic analysis of blood from case 2, a 4-year-old with suspected Turner syndrome revealed 45,X/46,X,del(Y)(q11.21). FISH analysis of the resected gonads (histologically = immature testes) confirmed an X/XY mosaic complement. Histologically, the gonadal tissue was testicular. Severe autolysis prohibited successful analysis in the 2 remaining cases. In summary, molecular cytogenetic evaluation of gonadal tissue from individuals with sex chromosomal and/or gonadal disorders did not reveal tissue-specific anomalies which could account for differences observed pathologically.

Chromosome

Science.gov (United States)

... St Louis, MO: Elsevier; 2017:chap 69. Taber's Medical Dictionary Online. Chromosome. www.tabers.com/tabersonline/view/Tabers-Dictionary/753321/all/chromosome?q=Chromosome&ti=0 . Accessed June 11, 2017.

Intrinsic bent DNA sites in the chromosomal replication origin of Xylella fastidiosa 9a5c

Directory of Open Access Journals (Sweden)

F. Gimenes

2008-04-01

Full Text Available The features of the nucleotide sequences in both replication and promoter regions have been investigated in many organisms. Intrinsically bent DNA sites associated with transcription have been described in several prokaryotic organisms. The aim of the present study was to investigate intrinsic bent DNA sites in the segment that holds the chromosomal replication origin, oriC, of Xylella fastidiosa 9a5c. Electrophoretic behavior analyses, as well as in silico analyses of both the 2-D projection and helical parameters, were performed. The chromosomal segment analyzed contains the initial sequence of the rpmH gene, an intergenic region, the dnaA gene, the oriC sequence, and the 5' partial sequence of the dnaN gene. The analysis revealed fragments with reduced electrophoretic mobility, which indicates the presence of curved DNA segments. The analysis of the helical parameter ENDS ratio revealed three bent DNA sites (b1, b2, and b3 located in the rpmH-dnaA intergenic region, the dnaA gene, and the oriC 5' end, respectively. The chromosomal segment of X. fastidiosa analyzed here is rich in phased AT tracts and in CAnT motifs. The 2-D projection indicated a segment whose structure was determined by the cumulative effect of all bent DNA sites. Further, the in silico analysis of the three different bacterial oriC sequences indicated similar negative roll and twist >34.00° values. The DnaA box sequences, and other motifs in them, may be associated with the intrinsic DNA curvature.

Flow Analysis and Sorting of Plant Chromosomes

Czech Academy of Sciences Publication Activity Database

Vrána, Jan; Cápal, Petr; Šimková, Hana; Karafiátová, Miroslava; Čížková, Jana; Doležel, Jaroslav

2016-01-01

Roč. 78, Oct 10 (2016), 5.3.1-5.3.43 ISSN 1934-9300 R&D Projects: GA MŠk(CZ) LO1204 Institutional support: RVO:61389030 Keywords : cell cycle synchronization * chromosome genomics * chromosome isolation Subject RIV: EB - Genetics ; Molecular Biology

High degree of sex chromosome differentiation in stickleback fishes

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Shimada Yukinori

2011-09-01

Full Text Available Abstract Background Studies of closely related species with different sex chromosome systems can provide insights into the processes of sex chromosome differentiation and evolution. To investigate the potential utility of molecular markers in studying sex chromosome differentiation at early stages of their divergence, we examined the levels and patterns of genetic differentiation between sex chromosomes in nine-spined (Pungitius pungitius and three-spined sticklebacks (Gasterosteus aculeatus using microsatellite markers. Results A set of novel microsatellite markers spanning the entire length of the sex chromosomes were developed for nine-spined sticklebacks using the sequenced genomes of other fish species. Sex-specific patterns of genetic variability and male-specific alleles were identified at most of these loci, indicating a high degree of differentiation between the X and Y chromosomes in nine-spined sticklebacks. In three-spined sticklebacks, male-specific alleles were detected at some loci confined to two chromosomal regions. In addition, male-specific null alleles were identified at several other loci, implying the absence of Y chromosomal alleles at these loci. Overall, male-specific alleles and null alleles were found over a region spanning 81% of the sex chromosomes in three-spined sticklebacks. Conclusions High levels but distinct patterns of sex chromosome differentiation were uncovered in the stickleback species that diverged 13 million years ago. Our results suggest that the Y chromosome is highly degenerate in three-spined sticklebacks, but not in nine-spined sticklebacks. In general, the results demonstrate that microsatellites can be useful in identifying the degree and patterns of sex chromosome differentiation in species at initial stages of sex chromosome evolution.

Process for assembly and transformation into Saccharomyces cerevisiae of a synthetic yeast artificial chromosome containing a multigene cassette to express enzymes that enhance xylose utilization designed for an automated pla

Science.gov (United States)

A yeast artificial chromosome (YAC) containing a multigene cassette for expression of enzymes that enhance xylose utilization (xylose isomerase [XI] and xylulokinase [XKS]) was constructed and transformed into Saccharomyces cerevisiae to demonstrate feasibility as a stable protein expression system ...

Chromosomal aberrations in benign prostatic hyperplasia patients

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Muammer Altok

2016-01-01

Full Text Available Purpose: To investigate the chromosomal changes in patients with benign prostatic hyperplasia (BPH. Materials and Methods: A total of 54 patients diagnosed with clinical BPH underwent transurethral prostate resection to address their primary urological problem. All patients were evaluated by use of a comprehensive medical history and rectal digital examination. The preoperative evaluation also included serum prostate-specific antigen (PSA measurement and ultrasonographic measurement of prostate volume. Prostate cancer was detected in one patient, who was then excluded from the study. We performed conventional cytogenetic analyses of short-term cultures of 53 peripheral blood samples obtained from the BPH patients. Results: The mean (±standard deviation age of the 53 patients was 67.8±9.4 years. The mean PSA value of the patients was 5.8±7.0 ng/mL. The mean prostate volume was 53.6±22.9 mL. Chromosomal abnormalities were noted in 5 of the 53 cases (9.4%. Loss of the Y chromosome was the most frequent chromosomal abnormality and was observed in three patients (5.7%. There was no statistically significant relationship among age, PSA, prostate volume, and chromosomal changes. Conclusions: Loss of the Y chromosome was the main chromosomal abnormality found in our study. However, this coexistence did not reach a significant level. Our study concluded that loss of the Y chromosome cannot be considered relevant for the diagnosis of BPH as it is for prostate cancer. Because BPH usually occurs in aging men, loss of the Y chromosome in BPH patients may instead be related to the aging process.

Chromosome polymorphism in a population of ceratitis capitata

International Nuclear Information System (INIS)

Lifschitz, E.

1987-08-01

A morphological chromosomal polymorphism along with the observation of B chromosomes in a natural population of Ceratitis capitata is reported. A variability affecting the centromere size of chromosome 3 is described. The observed B chromosome is minute, heterochromatic and telocentric. The B chromosome was found in the male and female germ cells and it exhibited, in the males, intra-individual numerical variation with OB and IB cells, which suggested a mitotic instability. It was also found, in both sexes, in somatic cells (cerebral ganglia tissue). Only males transmitted the B chromosomes to the progeny. The high rate of transmission suggested a differential utilization of the sperm carrying the B chromosomes or a preferential segregation into secondary spermatocytes. Previously reported linkage relationship between a pupal esterase gene (Est-1) and a pupa colour mutant (nig) has been extended to a line carrying a Y-chromosome (Y,B) shorter than the one previously studied (Y,A). Furthermore, an elaborate crossing scheme has been devised in order to estimate the recombination distances between these two genes and a third one affecting pupal length (lp-1). It is concluded that all three genes are in the same linkage group but Est-1 is far from the other two. In turn, nig and lp-1 are separated by 14.9 map units. It is confirmed that genetic recombination does not regularly occur at high frequency in the male and this frequency is not increased by the varying length of the Y-chromosome. Refs, figs, tabs

Production and repair of chromosome damage in an X-ray sensitive CHO mutant visualized and analysed in interphase using the technique of premature chromosome condensation

International Nuclear Information System (INIS)

Iliakis, G.E.; Pantelias, G.E.

1990-01-01

Production of chromosome damage per unit of absorbed radiation dose was in xrs-5 cells larger by a factor of 2.6 than in CHO cells (5.2 breaks per cell per Gy). Changes in chromatin structure, associated with the radiation-sensitive pheno-type of xrs-5 cells, that increase the probability of conversion of a DNA double-strand break (dsb) to a chromosome break are invoked to explain this. Repair of chromosome breaks as measured in plateau-phase G 1 cells was deficient in xrs-5 cells and the number of residual chromosome breaks practically identical to the number of lethal lesions calculated from survival data, suggesting that non-repaired chromosome breaks are likely to be manifestations of lethal events in the cell. The yield of ring chromosomes scored after a few hours of repair was higher by a factor of three in xrs-5 compared with CHO cells. (author)

Replicon sizes in mammalian cells as estimated by an x-ray plus bromodeoxyuridine photolysis method

International Nuclear Information System (INIS)

Kapp, L.N.; Painter, R.B.

1978-01-01

A new method is described for estimating replicon sizes in mammalian cells. Cultures were pulse labeled with [ 3 H]thymidine ([ 3 H]TdR) and bromodeoxyuridine (BrDUrd) for up to 1 h. The lengths of the resulting labeled regions of DNA, L/sub obs/, were estimated by a technique wherein the change in molecular weight of nascent DNA strands, induced by 313 nm light, is measured by velocity sedimentation in alkaline sucrose gradients. If cells are exposed to 1,000 rads of x rays immediately before pulse labeling, initiation of replicon operation is blocked, although chain elongation proceeds almost normally. Under these conditions L/sub obs/ continues to increase only until operating replicons have completed their replication. This value for L/sub obs/ then remains constant as long as the block to initiation remains and represents an estimate for the average size of replicons operating in the cells before x irradiation. For human diploid fibroblasts and human HeLa cells this estimated average size is approximately 17 μM, whereas for Chinese hamster ovary cells, the average replicon size is about 42 μM

Prevalence of chromosomal abnormalities and Y chromosome microdeletion among men with severe semen abnormalities and its correlation with successful sperm retrieval

Directory of Open Access Journals (Sweden)

Mariano Mascarenhas

2016-01-01

Full Text Available AIM: To estimate the prevalence of chromosomal abnormalities and Y chromosome microdeletion among men with azoospermia and severe oligozoospermia and its correlation with successful surgical sperm retrieval. SETTING AND DESIGN: A prospective study in a tertiary level infertility unit. MATERIALS AND METHODS: In a prospective observation study, men with azoospermia and severe oligozoospermia (concentration <5 million/ml attending the infertility center underwent genetic screening. Peripheral blood karyotype was done by Giemsa banding. Y chromosome microdeletion study was performed by a multiplex polymerase chain reaction. RESULTS: The study group consisted of 220 men, 133 of whom had azoospermia and 87 had severe oligozoospermia. Overall, 21/220 (9.5% men had chromosomal abnormalities and 13/220 (5.9% men had Y chromosome microdeletions. Chromosomal abnormalities were seen in 14.3% (19/133 of azoospermic men and Y chromosome microdeletions in 8.3% (11/133. Of the 87 men with severe oligozoospermia, chromosomal abnormalities and Y chromosome microdeletions were each seen in 2.3% (2/87. Testicular sperm aspiration was done in 13 men and was successful in only one, who had a deletion of azoospermia factor c. CONCLUSIONS: Our study found a fairly high prevalence of genetic abnormality in men with severe semen abnormalities and a correlation of genetic abnormalities with surgical sperm retrieval outcomes. These findings support the need for genetic screening of these men prior to embarking on surgical sperm retrieval and assisted reproductive technology intracytoplasmic sperm injection.

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)

Immediate bromodeoxyuridine labelling of unseparated human bone marrow cells ex vivo is superior to labelling after routine laboratory processing

DEFF Research Database (Denmark)

Jensen, P O; Mortensen, B T; Christensen, I J

1998-01-01

It is important to evaluate the proliferation of bone marrow cells in several disease conditions and during treatment of patients with for example cytokines. Labelling with bromodeoxyuridine (BrdUrd), immunocytochemical staining with anti-BrdUrd antibody and analysis by flow cytometry provides...... a reliable and reproducible technique for estimation of the fraction of cells that incorporated BrdUrd into DNA during S-phase. We have compared immediate BrdUrd labelling of unseparated bone marrow cells with the previously used labelling in the laboratory after routine separation of the mononuclear cells....... Bone marrow aspirates from seven lymphoma patients without bone marrow involvement were studied with these two methods. We found higher BrdUrd labelling indices (LI) in the mononuclear cells, when cells were labelled immediately. A large variation in LI was found between patients. Our results suggest...

Chromosome condensation and radiation-induced G2 arrest studied by the induction of premature chromosome condensation following cell fusion

International Nuclear Information System (INIS)

Mitchell, J.B.; Bedford, J.S.

1978-01-01

When mitotic and interphase cells are fused together, the chromosomes of the interphase cell sometimes condense prematurely. The phenomenon of premature chromosome condensation (PCC) was utilized in investigating the problem of whether the chromosomes of cells suffering a radiation-induced G 2 delay are capable of condensation. Colcemide-arrested mitotic cells were fused with synchronized G 2 cells, and with irradiated cells suffering a G 2 delay. The frequency of PCC in mitotic X G 2 binucleate cells was determined. This was compared to the PCC frequency in an unirradiated synchronized population rich in G 2 cells after fusion with mitotic cells. Flash-labelling with 3 HTdR and autoradiography allowed S-phase cells to be eliminated. The frequency of G 2 PCCs was not significantly different for the irradiated G 2 -delayed or unirradiated cells. From these results it was concluded that the chromosomes of cells suffering a G 2 arrest are capable of condensation, although the involvement of the condensation process in radiation-induced G 2 delay could not be ruled out. (author)

Dahl (S x R congenic strain analysis confirms and defines a chromosome 5 female-specific blood pressure quantitative trait locus to <7 Mbp.

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Victoria L M Herrera

Full Text Available The detection of multiple sex-specific blood pressure (BP quantitative trait loci (QTLs in independent total genome analyses of F2 (Dahl S x R-intercross male and female rat cohorts confirms clinical observations of sex-specific disease cause and response to treatment among hypertensive patients, and mandate the identification of sex-specific hypertension genes/mechanisms. We developed and studied two congenic strains, S.R5A and S.R5B introgressing Dahl R-chromosome 5 segments into Dahl S chromosome 5 region spanning putative BP-f1 and BP-f2 QTLs. Radiotelemetric non-stressed 24-hour BP analysis at four weeks post-high salt diet (8% NaCl challenge, identified only S.R5B congenic rats with lower SBP (-26.5 mmHg, P = 0.002, DBP (-23.7 mmHg, P = 0.004 and MAP (-25.1 mmHg, P = 0.002 compared with Dahl S female controls at four months of age confirming BP-f1 but not BP-f2 QTL on rat chromosome 5. The S.R5B congenic segment did not affect pulse pressure and relative heart weight indicating that the gene underlying BP-f1 does not influence arterial stiffness and cardiac hypertrophy. The results of our congenic analysis narrowed BP-f1 to chromosome 5 coordinates 134.9-141.5 Mbp setting up the basis for further fine mapping of BP-f1 and eventual identification of the specific gene variant accounting for BP-f1 effect on blood pressure.

Dahl (S x R) congenic strain analysis confirms and defines a chromosome 5 female-specific blood pressure quantitative trait locus to <7 Mbp.

Science.gov (United States)

Herrera, Victoria L M; Pasion, Khristine A; Moran, Ann Marie; Ruiz-Opazo, Nelson

2012-01-01

The detection of multiple sex-specific blood pressure (BP) quantitative trait loci (QTLs) in independent total genome analyses of F2 (Dahl S x R)-intercross male and female rat cohorts confirms clinical observations of sex-specific disease cause and response to treatment among hypertensive patients, and mandate the identification of sex-specific hypertension genes/mechanisms. We developed and studied two congenic strains, S.R5A and S.R5B introgressing Dahl R-chromosome 5 segments into Dahl S chromosome 5 region spanning putative BP-f1 and BP-f2 QTLs. Radiotelemetric non-stressed 24-hour BP analysis at four weeks post-high salt diet (8% NaCl) challenge, identified only S.R5B congenic rats with lower SBP (-26.5 mmHg, P = 0.002), DBP (-23.7 mmHg, P = 0.004) and MAP (-25.1 mmHg, P = 0.002) compared with Dahl S female controls at four months of age confirming BP-f1 but not BP-f2 QTL on rat chromosome 5. The S.R5B congenic segment did not affect pulse pressure and relative heart weight indicating that the gene underlying BP-f1 does not influence arterial stiffness and cardiac hypertrophy. The results of our congenic analysis narrowed BP-f1 to chromosome 5 coordinates 134.9-141.5 Mbp setting up the basis for further fine mapping of BP-f1 and eventual identification of the specific gene variant accounting for BP-f1 effect on blood pressure.

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

Loss of heterozygosity on chromosome 11p15.5 and relapse in hepatoblastomas.

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Chitragar, S; Iyer, V K; Agarwala, S; Gupta, S D; Sharma, A; Wari, M N

2011-01-01

IGF2 is a tumor suppressor gene at locus 11p15. Many hepatoblastomas have loss of heterozygosity (LOH) at this locus. Earlier studies have not demonstrated any association between LOH and prognosis. Aim of the study was to evaluate the prognostic significance of LOH at 11p15.5 in hepatoblastomas. DNA was isolated from normal liver and tumor tissue in 20 patients with hepatoblastoma. PCR was performed and cases were classified as LOH present, absent or non-informative. Patients' follow-up data was analyzed using Fischer's exact test and Kaplan-Meier survival analysis for relapse-free survival (RFS) in relation to LOH. Ethical clearance was obtained from the institutional ethics board. All cases were informative for at least one microsatellite marker used. 4 of the 20 cases (20%) had LOH at 11p15.5. One patient died in the immediate postoperative period. 5 of 19 patients relapsed (26%). Of 4 patients who had LOH, 3 (75%) relapsed, the time to relapse being 7, 7 and 9 months, respectively. Of the 15 cases without LOH, 2 (13.3%) relapsed. 4 patients had mixed epithelial and mesenchymal histology; 3 of them had LOH. The 2 groups with and without LOH were well matched. The RFS for patients with LOH (n=4) was 13% (mean survival time [MST]: 8.7 months; 95CI 6.7-10.7), while the RFS for cases without LOH (n=15) was 75% (MST: 100.7 months; 95CI 74.5-126.8). Mixed epithelial and mesenchymal histology is more frequently associated with LOH on chromosome 11p15.5 than pure epithelial histology. LOH on chromosome 11p15.5 is associated with a significantly increased incidence of relapse and a significantly shorter relapse-free survival in patients with hepatoblastoma. The risk of relapse is higher and the RFS lower both in standard-risk and high-risk patients with hepatoblastoma if they demonstrate the presence of LOH at 11p15.5. © Georg Thieme Verlag KG Stuttgart · New York.

Mapping of novel powdery mildew resistance gene(s) from Agropyron cristatum chromosome 2P.

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Li, Huanhuan; Jiang, Bo; Wang, Jingchang; Lu, Yuqing; Zhang, Jinpeng; Pan, Cuili; Yang, Xinming; Li, Xiuquan; Liu, Weihua; Li, Lihui

2017-01-01

A physical map of Agropyron cristatum 2P chromosome was constructed for the first time and the novel powdery mildew resistance gene(s) from chromosome 2P was(were) also mapped. Agropyron cristatum (L.) Gaertn. (2n = 28, PPPP), a wild relative of common wheat, is highly resistant to powdery mildew. Previous studies showed that wheat-A. cristatum 2P disomic addition line II-9-3 displayed high resistance to powdery mildew, and the resistance was attributable to A. cristatum chromosome 2P. To utilize and physically map the powdery mildew resistance gene(s), 15 wheat-A. cristatum 2P translocation lines and three A. cristatum 2P deletion lines with different chromosomal segment sizes, obtained from II-9-3 using 60 Co-γ ray irradiation, were characterized using cytogenetic and molecular marker analysis. A. cristatum 2P chromosomal segments in the translocations were translocated to different wheat chromosomes, including 1A, 4A, 5A, 6A, 7A, 1B, 2B, 3B, 7B, 3D, 4D, and 6D. A physical map of the 2P chromosome was constructed with 82 STS markers, consisting of nine bins with 34 markers on 2PS and eight bins with 48 markers on 2PL. The BC 1 F 2 populations of seven wheat-A. cristatum 2P translocation lines (2PT-3, 2PT-4, 2PT-5, 2PT-6, 2PT-8, 2PT-9, and 2PT-10) were developed by self-pollination, tested with powdery mildew and genotyped with 2P-specific STS markers. From these results, the gene(s) conferring powdery mildew resistance was(were) located on 2PL bin FL 0.66-0.86 and 19 2P-specific markers were identified in this bin. Moreover, two new powdery mildew-resistant translocation lines (2PT-4 and 2PT-5) with small 2PL chromosome segments were obtained. The newly developed wheat lines with powdery mildew resistance and the closely linked molecular markers will be valuable for wheat disease breeding in the future.

Study of radiation-induced chromosomal aberrations

International Nuclear Information System (INIS)

Wolfring, E.

2004-06-01

A method for determining chromosomal aberrations was established for the purpose of examining the relative biological effectiveness (RBE) of photon radiation with respect to mammary epithelium cells. Cells were exposed to 25 kV X-radiation and to 200 kV X-radiation for comparison and the resulting concentrations of chromosomal aberrations were compared. The RBE M value for radiation-induced fragmentation was found to be 4.2 ± 2.4, while the RBE M value for radiation-induced generation of dicentric chromosomes was found to be 0.5 ± 0.5. In addition to the evaluation of chromosomal aberrations the number of cell cycles undergone by the cells was monitored by means of BrDU staining. As expected, the proportion of cells which underwent more than one cell cycle following exposure to 5 Gy was very low in both cases, amounting to 1.9% (25 kV) and 3.2 (200 kV). Non-radiated cells yielded control values of 26.0% and 12.6%, suggesting variations in external conditions from day to day

Deficiência mental e malformações em criança com translocações cromossomicas 5/13 Mental retardation and malformation in a child with 5/13 chromosome translocation

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Valeriana Moura Ribeiro

1976-06-01

Full Text Available Os autores registram um caso raro de retardo mental e malformações físicas em paciente com anormalidades cromossômicas. A análise cromossômica do paciente revelou cariótipo aparentemente equilibrado. Entretanto, são consideradas as possibilidades de que nos eventos de quebra e rejunção dos cromossomos, tenha ocorrido perda de alguns genes para 5p e/ou 13q; mutação gênica ou, ainda, efeito de posições dos segmentos cromossômicos rearranjados.An unusual case of mental retardation and physical malformations with chromosome abnormalities in a 9 year old boy is reported. Chromosomal analy- sis showed either breakage and delation from some gens to 5p and/or 13q; genic mutation or, perhaps, efect of position in re-adjusted chromosomic segments.

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

Modifying effect of 5-fluoro-2-deoxyuridine and thymidine at G1 phase on radiation and chemically induced chromosome rearrangement

International Nuclear Information System (INIS)

Azatyan, R.A.; Voskanyan, A.Z.; Avakyan, V.A.; Akif'ev, A.P.

1978-01-01

The yield of structural chromosome mutations induced in Crepis capillaris seeds by X-rays and nitrogen mustard was studied as a function of treatment (at G 1 phase) with an inhibitor of unscheduled DNA synthesis, 5-fluoro-2-deoxyuridine (FdU), and its antagonist, thymidine. Air-dry seeds were irradiated at 10 krad and immediately placed in aqueous solutions of FdU, thymidine, or FdU + thymidine. Ionizing radiation induced only chromosome exchanges in the seeds. When EdU was used, the number of chromosome exchanges was the same although the fraction of simple and isolocus deletions was significantly greater than additive. The effect of FdU was manifested only after 10-hour incubation of the cells. Thymidine alone did not appreciably alter the frequency of radiation-induced aberrations. At the same time, the FdU + thymidine combination decreased the mutation yield i.e. was protective. Frequencies of the chromosome aberration in this experiment were the same as in the control

Fission yeast strains with circular chromosomes require the 9-1-1 checkpoint complex for the viability in response to the anti-cancer drug 5-fluorodeoxyuridine.

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Hossain Mohammad Shamim

Full Text Available Thymidine kinase converts 5-fluorodeoxyuridine to 5-fluorodeoxyuridine monophosphate, which causes disruption of deoxynucleotide triphosphate ratios. The fission yeast Schizosaccharomyces pombe does not express endogenous thymidine kinase but 5-fluorodeoxyuridine inhibits growth when exogenous thymidine kinase is expressed. Unexpectedly, we found that 5-fluorodeoxyuridine causes S phase arrest even without thymidine kinase expression. DNA damage checkpoint proteins such as the 9-1-1 complex were required for viability in the presence of 5-fluorodeoxyuridine. We also found that strains with circular chromosomes, due to loss of pot1+, which have higher levels of replication stress, were more sensitive to loss of the 9-1-1 complex in the presence of 5-fluorodeoxyuridine. Thus, our results suggest that strains carrying circular chromosomes exhibit a greater dependence on DNA damage checkpoints to ensure viability in the presence of 5-fluorodeoxyuridine compared to stains that have linear chromosomes.

Fission yeast strains with circular chromosomes require the 9-1-1 checkpoint complex for the viability in response to the anti-cancer drug 5-fluorodeoxyuridine.

Science.gov (United States)

Shamim, Hossain Mohammad; Minami, Yukako; Tanaka, Daiki; Ukimori, Shinobu; Murray, Johanne M; Ueno, Masaru

2017-01-01

Thymidine kinase converts 5-fluorodeoxyuridine to 5-fluorodeoxyuridine monophosphate, which causes disruption of deoxynucleotide triphosphate ratios. The fission yeast Schizosaccharomyces pombe does not express endogenous thymidine kinase but 5-fluorodeoxyuridine inhibits growth when exogenous thymidine kinase is expressed. Unexpectedly, we found that 5-fluorodeoxyuridine causes S phase arrest even without thymidine kinase expression. DNA damage checkpoint proteins such as the 9-1-1 complex were required for viability in the presence of 5-fluorodeoxyuridine. We also found that strains with circular chromosomes, due to loss of pot1+, which have higher levels of replication stress, were more sensitive to loss of the 9-1-1 complex in the presence of 5-fluorodeoxyuridine. Thus, our results suggest that strains carrying circular chromosomes exhibit a greater dependence on DNA damage checkpoints to ensure viability in the presence of 5-fluorodeoxyuridine compared to stains that have linear chromosomes.

Imaginal discs--a new source of chromosomes for genome mapping of the yellow fever mosquito Aedes aegypti.

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Maria V Sharakhova

2011-10-01

Full Text Available The mosquito Aedes aegypti is the primary global vector for dengue and yellow fever viruses. Sequencing of the Ae. aegypti genome has stimulated research in vector biology and insect genomics. However, the current genome assembly is highly fragmented with only ~31% of the genome being assigned to chromosomes. A lack of a reliable source of chromosomes for physical mapping has been a major impediment to improving the genome assembly of Ae. aegypti.In this study we demonstrate the utility of mitotic chromosomes from imaginal discs of 4(th instar larva for cytogenetic studies of Ae. aegypti. High numbers of mitotic divisions on each slide preparation, large sizes, and reproducible banding patterns of the individual chromosomes simplify cytogenetic procedures. Based on the banding structure of the chromosomes, we have developed idiograms for each of the three Ae. aegypti chromosomes and placed 10 BAC clones and a 18S rDNA probe to precise chromosomal positions.The study identified imaginal discs of 4(th instar larva as a superior source of mitotic chromosomes for Ae. aegypti. The proposed approach allows precise mapping of DNA probes to the chromosomal positions and can be utilized for obtaining a high-quality genome assembly of the yellow fever mosquito.

Features of the organization of bread wheat chromosome 5BS based on physical mapping

Czech Academy of Sciences Publication Activity Database

Salina, E.A.; Nesterov, V.; Frenkel, Z.; Kiseleva, V. I.; Timonova, E. M.; Magni, F.; Vrána, Jan; Šafář, Jan; Šimková, Hana; Doležel, Jaroslav; Korol, A.; Sergeeva, E.M.

2018-01-01

Roč. 19, FEB 9 (2018), č. článku 80. ISSN 1471-2164 R&D Projects: GA ČR GBP501/12/G090; GA MŠk(CZ) LO1204 Institutional support: RVO:61389030 Keywords : Chromosome 5BS * Genetic markers * Hexaploid wheat * Physical mapping * Sequencing * Synteny * Triticum aestivum Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Genetics and heredity (medical genetics to be 3) Impact factor: 3.729, year: 2016

5meCpG epigenetic marks neighboring a primate-conserved core promoter short tandem repeat indicate X-chromosome inactivation.

Science.gov (United States)

Machado, Filipe Brum; Machado, Fabricio Brum; Faria, Milena Amendro; Lovatel, Viviane Lamim; Alves da Silva, Antonio Francisco; Radic, Claudia Pamela; De Brasi, Carlos Daniel; Rios, Álvaro Fabricio Lopes; de Sousa Lopes, Susana Marina Chuva; da Silveira, Leonardo Serafim; Ruiz-Miranda, Carlos Ramon; Ramos, Ester Silveira; Medina-Acosta, Enrique

2014-01-01

X-chromosome inactivation (XCI) is the epigenetic transcriptional silencing of an X-chromosome during the early stages of embryonic development in female eutherian mammals. XCI assures monoallelic expression in each cell and compensation for dosage-sensitive X-linked genes between females (XX) and males (XY). DNA methylation at the carbon-5 position of the cytosine pyrimidine ring in the context of a CpG dinucleotide sequence (5meCpG) in promoter regions is a key epigenetic marker for transcriptional gene silencing. Using computational analysis, we revealed an extragenic tandem GAAA repeat 230-bp from the landmark CpG island of the human X-linked retinitis pigmentosa 2 RP2 promoter whose 5meCpG status correlates with XCI. We used this RP2 onshore tandem GAAA repeat to develop an allele-specific 5meCpG-based PCR assay that is highly concordant with the human androgen receptor (AR) exonic tandem CAG repeat-based standard HUMARA assay in discriminating active (Xa) from inactive (Xi) X-chromosomes. The RP2 onshore tandem GAAA repeat contains neutral features that are lacking in the AR disease-linked tandem CAG repeat, is highly polymorphic (heterozygosity rates approximately 0.8) and shows minimal variation in the Xa/Xi ratio. The combined informativeness of RP2/AR is approximately 0.97, and this assay excels at determining the 5meCpG status of alleles at the Xp (RP2) and Xq (AR) chromosome arms in a single reaction. These findings are relevant and directly translatable to nonhuman primate models of XCI in which the AR CAG-repeat is monomorphic. We conducted the RP2 onshore tandem GAAA repeat assay in the naturally occurring chimeric New World monkey marmoset (Callitrichidae) and found it to be informative. The RP2 onshore tandem GAAA repeat will facilitate studies on the variable phenotypic expression of dominant and recessive X-linked diseases, epigenetic changes in twins, the physiology of aging hematopoiesis, the pathogenesis of age-related hematopoietic

5meCpG epigenetic marks neighboring a primate-conserved core promoter short tandem repeat indicate X-chromosome inactivation.

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Filipe Brum Machado

Full Text Available X-chromosome inactivation (XCI is the epigenetic transcriptional silencing of an X-chromosome during the early stages of embryonic development in female eutherian mammals. XCI assures monoallelic expression in each cell and compensation for dosage-sensitive X-linked genes between females (XX and males (XY. DNA methylation at the carbon-5 position of the cytosine pyrimidine ring in the context of a CpG dinucleotide sequence (5meCpG in promoter regions is a key epigenetic marker for transcriptional gene silencing. Using computational analysis, we revealed an extragenic tandem GAAA repeat 230-bp from the landmark CpG island of the human X-linked retinitis pigmentosa 2 RP2 promoter whose 5meCpG status correlates with XCI. We used this RP2 onshore tandem GAAA repeat to develop an allele-specific 5meCpG-based PCR assay that is highly concordant with the human androgen receptor (AR exonic tandem CAG repeat-based standard HUMARA assay in discriminating active (Xa from inactive (Xi X-chromosomes. The RP2 onshore tandem GAAA repeat contains neutral features that are lacking in the AR disease-linked tandem CAG repeat, is highly polymorphic (heterozygosity rates approximately 0.8 and shows minimal variation in the Xa/Xi ratio. The combined informativeness of RP2/AR is approximately 0.97, and this assay excels at determining the 5meCpG status of alleles at the Xp (RP2 and Xq (AR chromosome arms in a single reaction. These findings are relevant and directly translatable to nonhuman primate models of XCI in which the AR CAG-repeat is monomorphic. We conducted the RP2 onshore tandem GAAA repeat assay in the naturally occurring chimeric New World monkey marmoset (Callitrichidae and found it to be informative. The RP2 onshore tandem GAAA repeat will facilitate studies on the variable phenotypic expression of dominant and recessive X-linked diseases, epigenetic changes in twins, the physiology of aging hematopoiesis, the pathogenesis of age-related hematopoietic

Frequencies of chromosome aberration on radiation workers

International Nuclear Information System (INIS)

Yanti Lusiyanti; Zubaidah Alatas

2016-01-01

Radiation exposure of the body can cause damage to the genetic material in cells (cytogenetic) in the form of changes in the structure or chromosomal aberrations in peripheral blood lymphocytes. Chromosomal aberrations can be unstable as dicentric and ring chromosomes, and is stable as translocation. Dicentric chromosome is the gold standard biomarker due to radiation exposure, and chromosome translocation is a biomarker for retrospective biodosimetry. The aim of this studi is to conduct examination of chromosomal aberrations in the radiation worker to determine the potential damage of cell that may arise due to occupational radiation exposure. The examination have been carried out on blood samples from 55 radiation workers in the range of 5-30 year of service. Chromosome aberration frequency measurement starts with blood sampling, culturing, harvesting, slide preparations, and lymphocyte chromosome staining with Giemsa and painting with Fluorescence In Situ Hybridization (FISH) technique. The results showed that chromosomal translocations are not found in blood samples radiation workers and dicentric chromosomes found only on 2 blood samples of radiation workers with a frequency of 0.001/cell. The frequency of chromosomal aberrations in the blood cells such workers within normal limits and this means that the workers have been implemented a radiation safety aspects very well. (author)

Radiation induced chromosome aberrations and interphase DNA geometry

International Nuclear Information System (INIS)

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

1995-01-01

Ionizing radiation induces DNA double strand breaks (DSBs) and their interaction and illegitimate recombination produces chromosome aberrations. Stable chromosome aberrations comprise inter-chromosomal events (translocations) and intra-chromosomal events (inversions). Assuming DSBs induction and interaction is completely random and neglecting proximity effects, the expected ratio of translocations to inversions is F=86, based on chromosome arm lengths. We analyzed the number of translocations and inversions using G-banding, in 16 lymphocyte cultures from blood samples acutely irradiated with γ-rays (dose range: 0.5Gy-3Gy). Our results give 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 an extra probability of interaction. 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. We assume a DSBs interaction probability function with cut-off length = 1 μ. We propose that large spread in F data could be due to temporal variation in overlapping and spatial chromosome confinement. (author). 14 refs

Chromosomal localization of the human diazepam binding inhibitor gene

International Nuclear Information System (INIS)

DeBernardi, M.A.; Crowe, R.R.; Mocchetti, I.; Shows, T.B.; Eddy, R.L.; Costa, E.

1988-01-01

The authors have used in situ chromosome hybridization and human-mouse somatic cell hybrids to map the gene(s) for human diazepam binding inhibitor (DBI), an endogenous putative modulator of the γ-aminobutyric acid receptor acting at the allosteric regulatory center of this receptor that includes the benzodiazepine recognition site. In 784 chromosome spreads hybridized with human DBI cDNA, the distribution of 1,476 labeled sites revealed a significant clustering of autoradiographic grains (11.3% of total label) on the long arm of chromosome 2 (2q). Furthermore, 63.5% of the grains found on 2q were located on 2q12-21, suggesting regional mapping of DBI gene(s) to this segment. Secondary hybridization signals were frequently observed on other chromosomes and they were statistically significant mainly for chromosomes 5, 6, 11, and 14. In addition, DNA from 32 human-mouse cell hybrids was digested with BamHI and probed with human DBI cDNA. A 3.5-kilobase band, which probably represents the human DBI gene, was assigned to chromosome 2. Four higher molecular weight bands, also detected in BamHI digests, could not be unequivocally assigned. A chromosome 2 location was excluded for the 27-, 13-, and 10-kilobase bands. These results assign a human DBI gene to chromosome 2 (2q12-21) and indicate that three of the four homologous sequences detected by the human DBI probe are located on three other chromosomes

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

Meiotic double-strand breaks at the interface of chromosome movement, chromosome remodeling, and reductional division

Science.gov (United States)

Storlazzi, Aurora; Tessé, Sophie; Gargano, Silvana; James, Françoise; Kleckner, Nancy; Zickler, Denise

2003-01-01

Chromosomal processes related to formation and function of meiotic chiasmata have been analyzed in Sordaria macrospora. Double-strand breaks (DSBs), programmed or γ-rays-induced, are found to promote four major events beyond recombination and accompanying synaptonemal complex formation: (1) juxtaposition of homologs from long-distance interactions to close presynaptic coalignment at midleptotene; (2) structural destabilization of chromosomes at leptotene/zygotene, including sister axis separation and fracturing, as revealed in a mutant altered in the conserved, axis-associated cohesin-related protein Spo76/Pds5p; (3) exit from the bouquet stage, with accompanying global chromosome movements, at zygotene/pachytene (bouquet stage exit is further found to be a cell-wide regulatory transition and DSB transesterase Spo11p is suggested to have a new noncatalytic role in this transition); (4) normal occurrence of both meiotic divisions, including normal sister separation. Functional interactions between DSBs and the spo76-1 mutation suggest that Spo76/Pds5p opposes local destabilization of axes at developing chiasma sites and raise the possibility of a regulatory mechanism that directly monitors the presence of chiasmata at metaphase I. Local chromosome remodeling at DSB sites appears to trigger an entire cascade of chromosome movements, morphogenetic changes, and regulatory effects that are superimposed upon a foundation of DSB-independent processes. PMID:14563680

Rumex acetosa Y chromosomes: constitutive or facultative heterochromatin?

Science.gov (United States)

Mosiołek, Magdalena; Pasierbek, Paweł; Malarz, Janusz; Moś, Maria; Joachimiak, Andrzej J

2005-01-01

Condensed Y chromosomes in Rumex acetosa L. root-tip nuclei were studied using 5-azaC treatment and immunohistochemical detection of methylated histones. Although Y chromosomes were decondensed within root meristem in vivo, they became condensed and heteropycnotic in roots cultured in vitro. 5-azacytidine (5-azaC) treatment of cultured roots caused transitional dispersion of their Y chromosome bodies, but 7 days after removal of the drug from the culture medium, Y heterochromatin recondensed and again became visible. The response of Rumex sex chromatin to 5-azaC was compared with that of condensed segments of pericentromeric heterochromatin in Rhoeo spathacea (Sw.) Steam roots. It was shown that Rhoeo chromocentres, composed of AT-rich constitutive heterochromatin, did not undergo decondensation after 5-azaC treatment. The Y-bodies observed within male nuclei of R. acetosa were globally enriched with H3 histone, demethylated at lysine 4 and methylated at lysine 9. This is the first report of histone tail-modification in condensed sex chromatin in plants. Our results suggest that the interphase condensation of Y chromosomes in Rumex is facultative rather than constitutive. Furthermore, the observed response of Y-bodies to 5-azaC may result indirectly from demethylation and the subsequent altered expression of unknown genes controlling tissue-specific Y-inactivation as opposed to the global demethylation of Y-chromosome DNA.

Molecular analysis of human complement component C5: localization of the structural gene to chromosome 9

International Nuclear Information System (INIS)

Wetsel, R.A.; Lemons, R.S.; Le Beau, M.M.; Barnum, S.R.; Noack, D.; Tack, B.F.

1988-01-01

A human C5 clone (pC5HG2) was isolated from a cDNA library constructed from Hep G2 mRNA. he DNA sequence showed that the pC5HG2 insert was comprised of 3309 base pairs of pro-C5 coding sequence and 404 base pairs of 3'-untranslated sequence. The derived amino acid sequence contained the entire coding sequence of the C5 α-chain, the β-α-chain junction region, and 100 amino acids (approximately 50%) of the β-chain. Protein sequences of four C5 tryptic peptides were aligned exactly to this sequence and demonstrated that C5 synthesized and secreted by Hep G2 cells is probably identical with plasma-derived C5. Coding sequence alignment of the human C5 sequences with those of murine C5 indicated that 80% of the nucleotides and 79% of the amino acids were placed identically in the two species. Amino acid sequence alignment of the homologous family members C3, C4, and α 2 -macroglobulin with that of C5 demonstrated 27%, 25%, and 19% identity, respectively. As was found in murine C5, the corresponding thiol ester region of human C5 contained several conserved amino acids, but the critical cysteine and glutamine residues which give rise to the intramolecular thiol ester bond in C3, C4, and α 2 -macroglobulin were absent in C5, having been replaced by serine and alanine, respectively. With the use of a panel of hamster-human somatic cell hybrids, the C5 gene was mapped to human chromosome 9. In situ chromosomal hybridization studies employing metaphase cells further localized the gene to bands 9q32-34, with the largest cluster of grains at 9q34.1

Fetal chromosome analysis: screening for chromosome disease?

DEFF Research Database (Denmark)

Philip, J; Tabor, Ann; Bang, J

1983-01-01

The aim of the study was to investigate the rationale of the current indications for fetal chromosome analysis. 5372 women had 5423 amniocentesis performed, this group constituting a consecutive sample at the chromosome laboratory, Rigshospitalet, Copenhagen from March 1973 to September 1980 (Group...... A + B). Pregnant women 35 years of age, women who previously had a chromosomally abnormal child, families with translocation carriers or other heritable chromosomal disease, families where the father was 50 years or more and women in families with a history of Down's syndrome (group A), were compared...... to women having amniocentesis, although considered not to have any increased risk of fetal chromosome abnormality (1390 pregnancies, group B). They were also compared with 750 consecutive pregnancies in women 25-34 years of age, in whom all heritable diseases were excluded (group C). The risk of unbalanced...

A simple chromosomal marker can reliably distinguishes Poncirus from Citrus species.

Science.gov (United States)

Brasileiro-Vidal, A C; Dos Santos-Serejo, J A; Soares Filho, W Dos S; Guerra, M

2007-03-01

Several chromosome types have been recognized in Citrus and related genera by chromomycin A(3 )(CMA) banding patterns and fluorescent in situ hybridization (FISH). They can be used to characterize cultivars and species or as markers in hybridization and backcrossing experiments. In the present work, characterization of six cultivars of P. trifoliata ("Barnes", "Fawcett", "Flying Dragon", "Pomeroy", "Rubidoux", "USDA") and one P. trifoliata x C. limonia hybrid was performed by sequential analyses of CMA banding and FISH using 5S and 45S rDNA as probes. All six cultivars showed a similar CMA(+) banding pattern with the karyotype formula 4B + 8D + 6F. The capital letters indicate chromosomal types: B, a chromosome with one telomeric and one proximal band; D, with only one telomeric band; F, without bands. In situ hybridization labeling was also similar among cultivars. Three chromosome pairs displayed a closely linked set of 5S and 45S rDNA sites, two of them co-located with the proximal band of the B type chromosomes (B/5S-45S) and the third one co-located with the terminal band of a D pair (D/5S-45S). The B/5S-45S chromosome has never been found in any citrus accessions investigated so far. Therefore, this B chromosome can be used as a marker to recognize the intergeneric Poncirus x Citrus hybrids. The intergeneric hybrid analyzed here displayed the karyotype formula 4B + 8D + 6F, with two chromosome types B/5S-45S and two D/5S-45S. The karyotype formula and the presence of two B/5S-45S chromosomes clearly indicate that the plant investigated is a symmetric hybrid. It also demonstrates the suitability of karyotype analyses to differentiate zygotic embryos or somatic cell fusions involving trifoliate orange germplasm.

BCR translocation to derivative chromosome 2, a new case of chronic myeloid leukemia with complex variant translocation and Philadelphia chromosome

International Nuclear Information System (INIS)

Al-Achkar, W.; Wafa, A.; Al-Medani, S.

2011-01-01

The well-known typical fusion gene BCR/ABL can be observed in connection with a complex translocation event in only 5-8% of cases with chronic myeloid leukemia (CML). Herein we report an exceptional CML case with complex chromosomal aberrations not observed before, translocated BCR to the derivative chromosome 2 [der(2)], additional to involving a four chromosomes translocation implying chromosomal regions such as 1p32 and 2q21 besides 9q34 and 22q11.2. Which were characterized by molecular cytogenetics. (author)

[Utility of chromosome banding with ALU I enzyme for identifying methylated areas in breast cancer].

Science.gov (United States)

Rojas-Atencio, Alicia; Yamarte, Leonard; Urdaneta, Karelis; Soto-Alvarez, Marisol; Alvarez Nava, Francisco; Cañizalez, Jenny; Quintero, Maribel; Atencio, Raquel; González, Richard

2012-12-01

Cancer is a group of disorders characterized by uncontrolled cell growth which is produced by two successive events: increased cell proliferation (tumor or neoplasia) and the invasive capacity of these cells (metastasis). DNA methylation is an epigenetic process which has been involved as an important pathogenic factor of cancer. DNA methylation participates in the regulation of gene expression, directly, by preventing the union of transcription factors, and indirectly, by promoting the "closed" structure of the chromatine. The objectives of this study were to identify hypermethyled chromosomal regions through the use of restriction Alu I endonuclease, and to relate cytogenetically these regions with tumor suppressive gene loci. Sixty peripheral blood samples of females with breast cancer were analyzed. Cell cultures were performed and cytogenetic spreads, previously digested with Alu I enzyme, were stained with Giemsa. Chromosomal centromeric and not centromeric regions were stained in 37% of cases. About 96% of stained hypermethyled chromosomal regions (1q, 2q, 6q) were linked with methylated genes associated with breast cancer. In addition, centromeric regions in chromosomes 3, 4, 8, 13, 14, 15 and 17, usually unstained, were found positive to digestion with Alu I enzime and Giemsa staining. We suggest the importance of this technique for the global visualization of the genome which can find methylated genes related to breast cancer, and thus lead to a specific therapy, and therefore a better therapeutic response.

Chromosome abnormalities in atomic bomb survivors

Energy Technology Data Exchange (ETDEWEB)

Tomonaga, Y [Nagasaki Univ. (Japan). School of Medicine

1976-09-01

Chromosome abnormalities in bone marrow cells were recognized in 6 cases which consisted of one case of chronic myelogenous leukemia, two cases of acute myelogenous leukemia, one case of sideroblastic anemia, and two cases of myelodysplasis. Frequency of stable type chromosome abnormalities in bone marrow cells was investigated in 45 atomic bomb survivors without hematologic disorders and 15 controls. It was 1.4% (15 cases) in the group exposed to atomic bomb within 1 km from the hypocenter, which was significantly higher as compared with 0.1% (15 cases) in the group exposed to atomic bomb over 2.5 km from the hypocenter and 0.2% in normal controls. Examination of chromosome was also made on 2 of 3 cases which were the seconds born of female with high chromosome abnormality, who was exposed to within 1 km from the hypocenter, and healthy male exposed 3 km from the hypocenter. These two cases showed chromosome of normal male type, and balanced translocation was not recognized. There was not a significant difference in chromosome abnormalities between the seconds of atomic bomb survivors and controls.

Neocentromeres Provide Chromosome Segregation Accuracy and Centromere Clustering to Multiple Loci along a Candida albicans Chromosome.

Directory of Open Access Journals (Sweden)

Laura S Burrack

2016-09-01

Full Text Available Assembly of kinetochore complexes, involving greater than one hundred proteins, is essential for chromosome segregation and genome stability. Neocentromeres, or new centromeres, occur when kinetochores assemble de novo, at DNA loci not previously associated with kinetochore proteins, and they restore chromosome segregation to chromosomes lacking a functional centromere. Neocentromeres have been observed in a number of diseases and may play an evolutionary role in adaptation or speciation. However, the consequences of neocentromere formation on chromosome missegregation rates, gene expression, and three-dimensional (3D nuclear structure are not well understood. Here, we used Candida albicans, an organism with small, epigenetically-inherited centromeres, as a model system to study the functions of twenty different neocentromere loci along a single chromosome, chromosome 5. Comparison of neocentromere properties relative to native centromere functions revealed that all twenty neocentromeres mediated chromosome segregation, albeit to different degrees. Some neocentromeres also caused reduced levels of transcription from genes found within the neocentromere region. Furthermore, like native centromeres, neocentromeres clustered in 3D with active/functional centromeres, indicating that formation of a new centromere mediates the reorganization of 3D nuclear architecture. This demonstrates that centromere clustering depends on epigenetically defined function and not on the primary DNA sequence, and that neocentromere function is independent of its distance from the native centromere position. Together, the results show that a neocentromere can form at many loci along a chromosome and can support the assembly of a functional kinetochore that exhibits native centromere functions including chromosome segregation accuracy and centromere clustering within the nucleus.

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.

Rumex acetosa Y chromosomes: constitutive or facultative heterochromatin?

Directory of Open Access Journals (Sweden)

Andrzej J. Joachimiak

2011-08-01

Full Text Available Condensed Y chromosomes in Rumex acetosa L. root-tip nuclei were studied using 5-azaC treatment and immunohistochemical detection of methylated histones. Although Y chromosomes were decondensed within root meristem in vivo, they became condensed and heteropycnotic in roots cultured in vitro. 5-azacytidine (5-azaC treatment of cultured roots caused transitional dispersion of their Y chromosome bodies, but 7 days after removal of the drug from the culture medium, Y heterochromatin recondensed and again became visible. The response of Rumex sex chromatin to 5-azaC was compared with that of condensed segments of pericentromeric heterochromatin in Rhoeo spathacea (Sw. Stearn roots. It was shown that Rhoeo chromocentres, composed of AT-rich constitutive heterochromatin, did not undergo decondensation after 5-azaC treatment. The Y-bodies observed within male nuclei of R. acetosa were globally enriched with H3 histone, demethylated at lysine 4 and methylated at lysine 9. This is the first report of histone tail-modification in condensed sex chromatin in plants. Our results suggest that the interphase condensation of Y chromosomes in Rumex is facultative rather than constitutive. Furthermore, the observed response of Y-bodies to 5-azaC may result indirectly from demethylation and the subsequent altered expression of unknown genes controlling tissue-specific Y-inactivation as opposed to the global demethylation of Y-chromosome DNA.

One in Four Individuals of African-American Ancestry Harbors a 5.5kb Deletion at chromosome 11q13.1

Science.gov (United States)

Zainabadi, Kayvan; Jain, Anuja V.; Donovan, Frank X.; Elashoff, David; Rao, Nagesh P.; Murty, Vundavalli V.; Chandrasekharappa, Settara C.; Srivatsan, Eri S.

2014-01-01

Cloning and sequencing of 5.5kb deletion at chromosome 11q13.1 from the HeLa cells, tumorigenic hybrids and two fibroblast cell lines has revealed homologous recombination between AluSx and AluY resulting in the deletion of intervening sequences. Long-range PCR of the 5.5kb sequence in 494 normal lymphocyte samples showed heterozygous deletion in 28.3% of African- American ancestry samples but only in 4.8% of Caucasian samples (pdeletion occurs in 27% of YRI (Yoruba – West African) population but none in non-African populations. The HapMap analysis further identified strong linkage disequilibrium between 5 single nucleotide polymorphisms and the 5.5kb deletion in the people of African ancestry. Computational analysis of 175kb sequence surrounding the deletion site revealed enhanced flexibility, low thermodynamic stability, high repetitiveness, and stable stem-loop/hairpin secondary structures that are hallmarks of common fragile sites. PMID:24412158

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.

Exceptional Complex Chromosomal Rearrangements in Three Generations

Directory of Open Access Journals (Sweden)

Hannie Kartapradja

2015-01-01

Full Text Available We report an exceptional complex chromosomal rearrangement (CCR found in three individuals in a family that involves 4 chromosomes with 5 breakpoints. The CCR was ascertained in a phenotypically abnormal newborn with additional chromosomal material on the short arm of chromosome 4. Maternal karyotyping indicated that the mother carried an apparently balanced CCR involving chromosomes 4, 6, 11, and 18. Maternal transmission of the derivative chromosome 4 resulted in partial trisomy for chromosomes 6q and 18q and a partial monosomy of chromosome 4p in the proband. Further family studies found that the maternal grandmother carried the same apparently balanced CCR as the proband’s mother, which was confirmed using the whole chromosome painting (WCP FISH. High resolution whole genome microarray analysis of DNA from the proband’s mother found no evidence for copy number imbalance in the vicinity of the CCR translocation breakpoints, or elsewhere in the genome, providing evidence that the mother’s and grandmother’s CCRs were balanced at a molecular level. This structural rearrangement can be categorized as an exceptional CCR due to its complexity and is a rare example of an exceptional CCR being transmitted in balanced and/or unbalanced form across three generations.

Heterozygous effects of irradiated chromosomes on viability in Drosophila melanogaster

International Nuclear Information System (INIS)

Simmons, M.J.

1976-01-01

Two large experiments were conducted in order to evaluate the heterozygous effects of irradiated chromosomes on viability. Mutations were accumulated on several hundred second chromosomes by delivering doses of 2,500R over either two or four generations for total x-ray exposures of 5,000R or 10,000R. Chromosomes treated with 5,000R were screened for lethals after the first treatment, and surviving nonlethals were used to generate families of fully treated chromosomes. The members of these families shared the effects of the first irradiation, but differed with respect to those of the second. The chromosomes treated with 10,000R were not grouped into families since mutations were accumulated independently on each chromosome in that experiment. Heterozygous effects on viability of the irradiated chromosomes were tested in both isogenic (homozygous) and nonisogenic (heterozygous) genetic backgrounds. In conjunction with these tests, homozygous viabilities were determined by the marked-inversion technique. This permitted a separation of the irradiated chromosomes into those which were drastic when made homozygous and those which were not. The results indicate that drastic chromosomes have deleterious effects in heterozygous condition, since viability was reduced by 2 to 4 percent in tests performed with the 10,000R chromosomes, and by 1 percent in those involving the 5,000R material. Within a series of tests, the effects were more pronounced when the genetic background was homozygous. These results suggest that the mutants induced by high doses of x-rays are principally drastic ones which show deleterious effects on viability in heterozygous condition

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

Eosinophilic fasciitis associated with hypereosinophilia, abnormal bone-marrow karyotype and inversion of chromosome 5.

Science.gov (United States)

Ferguson, J S; Bosworth, J; Min, T; Mercieca, J; Holden, C A

2014-03-01

We report the case of a male patient presenting with eosinophilia, pulmonary oedema and eosinophilic fasciitis (EF). He had the classic clinical appearance and magnetic resonance imaging of EF. Cytogenetic analysis of the bone marrow revealed a previously undescribed pericentric inversion of chromosome 5. Overall, the presentation was consistent with a diagnosis of chronic eosinophilic leukaemia, not otherwise specified (CEL-NOS). Dermatologists should consult a haematologist in cases of EF, in order to rule out possible haematological malignancies. © 2013 British Association of Dermatologists.

Mitotic chromosome structure

International Nuclear Information System (INIS)

Heermann, Dieter W.

2012-01-01

Mounting evidence is compiling linking the physical organizational structure of chromosomes and the nuclear structure to biological function. At the base of the physical organizational structure of both is the concept of loop formation. This implies that physical proximity within chromosomes is provided for otherwise distal genomic regions and thus hierarchically organizing the chromosomes. Together with entropy many experimental observations can be explained with these two concepts. Among the observations that can be explained are the measured physical extent of the chromosomes, their shape, mechanical behavior, the segregation into territories (chromosomal and territories within chromosomes), the results from chromosome conformation capture experiments, as well as linking gene expression to structural organization.

Mitotic chromosome structure

Energy Technology Data Exchange (ETDEWEB)

Heermann, Dieter W., E-mail: heermann@tphys.uni-heidelberg.de

2012-07-15

Mounting evidence is compiling linking the physical organizational structure of chromosomes and the nuclear structure to biological function. At the base of the physical organizational structure of both is the concept of loop formation. This implies that physical proximity within chromosomes is provided for otherwise distal genomic regions and thus hierarchically organizing the chromosomes. Together with entropy many experimental observations can be explained with these two concepts. Among the observations that can be explained are the measured physical extent of the chromosomes, their shape, mechanical behavior, the segregation into territories (chromosomal and territories within chromosomes), the results from chromosome conformation capture experiments, as well as linking gene expression to structural organization.

Numerical chromosome errors in day 7 somatic nuclear blastocysts

DEFF Research Database (Denmark)

Booth, Paul J; Viuff, Dorthe; Tan, Shijian J

2003-01-01

Day 7 bovine somatic nuclear transfer (NT) embryos reconstructed from granulosa cells were examined for numerical chromosome aberrations as a potential cause of the high embryonic and fetal loss observed in such embryos after transfer. The NT embryos were reconstructed using a zona-free manipulat......Day 7 bovine somatic nuclear transfer (NT) embryos reconstructed from granulosa cells were examined for numerical chromosome aberrations as a potential cause of the high embryonic and fetal loss observed in such embryos after transfer. The NT embryos were reconstructed using a zona...... families, consisting of 112 blastocysts reconstructed from five different primary granulosa cell cultures, were examined. Overall, the mean chromosome complement within embryos was 86.9 +/- 3.7% (mean +/- SEM) diploid, 2.6 +/- 0.5% triploid, 10.0 +/- 3.1% tetraploid, and 0.5 +/- 0.2% pentaploid or greater......; the vast majority (>75%) of the abnormal nuclei were tetraploid. Completely diploid and mixoploid embryos represented 22.1 +/- 4.5% and 73.7 +/- 5.5%, respectively, of all clones. Six totally polyploid blastocysts, containing or=5N chromosome complements, respectively) between two clone families were...

Chromosome End Repair and Genome Stability in Plasmodium falciparum

Directory of Open Access Journals (Sweden)

Susannah F. Calhoun

2017-08-01

Full Text Available The human malaria parasite Plasmodium falciparum replicates within circulating red blood cells, where it is subjected to conditions that frequently cause DNA damage. The repair of DNA double-stranded breaks (DSBs is thought to rely almost exclusively on homologous recombination (HR, due to a lack of efficient nonhomologous end joining. However, given that the parasite is haploid during this stage of its life cycle, the mechanisms involved in maintaining genome stability are poorly understood. Of particular interest are the subtelomeric regions of the chromosomes, which contain the majority of the multicopy variant antigen-encoding genes responsible for virulence and disease severity. Here, we show that parasites utilize a competitive balance between de novo telomere addition, also called “telomere healing,” and HR to stabilize chromosome ends. Products of both repair pathways were observed in response to DSBs that occurred spontaneously during routine in vitro culture or resulted from experimentally induced DSBs, demonstrating that both pathways are active in repairing DSBs within subtelomeric regions and that the pathway utilized was determined by the DNA sequences immediately surrounding the break. In combination, these two repair pathways enable parasites to efficiently maintain chromosome stability while also contributing to the generation of genetic diversity.

Philadelphia chromosome-positive adult acute leukemia with monosomy of chromosome number seven: a subgroup with poor response to therapy.

Science.gov (United States)

Maddox, A M; Keating, M J; Trujillo, J; Cork, A; Youness, E; Ahearn, M J; McCredie, K B; Freireich, E J

1983-01-01

Thirty-four adult patients were seen at the University of Texas M. D. Anderson Hospital and Tumor Institute at Houston, Texas between 1969 and 1980 with acute leukemia (AL) and a deleted G-group chromosome that was shown by Giemsa banding to be a Philadelphia (Ph1) chromosome t(9;22) in 21 patients. Fourteen had the Ph1 chromosome as the sole abnormality, 12 had the Ph1 chromosome and loss of one chromosome of the C-group (identified by Giemsa banding analysis as number 7 in eight patients), while eight had the Ph1 chromosome and other changes. These three groups were similar in sex, age distribution and hematologic parameters. The median age of 40 was lower than usually seen in AL. The distribution of the morphologic subtypes was similar to that seen at this institution, with 50% being acute myeloblastic, 12% acute myelomonocytic, 20% lymphoblastic and 18% acute undifferentiated. The complete remission rate with chemotherapy was low: 25% in the Ph1 +/- 7, 50% in the Ph1 +/other group and 43% in the Ph1 +/other group. Median survival time was 8 months for the Ph1 +/- 7 group, 5.5 months for the Ph1 +/other group and 9.0 months for the Ph1 +/alone group. These patients with Ph1 + AL had higher white blood cell counts, increased extramedullary disease and poorer responses to therapy than usual for patients with AL. The deletion of chromosome 7 and the acquisition of the Ph1 chromosome identifies a group of patients with characteristics similar to all the patients with Ph1 + AL but a poor response to therapy and short remission duration.

Chromosomal aberrations and micronuclei frequencies in Bulgarian control population

International Nuclear Information System (INIS)

Popova, I.; Hadjidekova, V.; Hristova, R.; Atanasova, P.

2004-01-01

The aim of this investigation is to represent the frequency of spontaneous chromosomal damages in peripheral blood lymphocytes of Bulgarian control population. Material and methods: The investigated group includes persons belonging to both sexes and different ages. Each of them is interviewed of their social and health status. Sixteen persons are examined using the chromosomal aberrations analysis and forty-five with micronucleus test. The frequency of chromosomal aberrations varied between 0 - 2.4 % and the mean value is 1.00 %. The frequency of cells with micronuclei varied between 4.5 - 24.5 % and the mean value 12,9 %. Further work on the investigation of spontaneous frequency of chromosomal damages is in progress. (authors)

MLL/WDR5 Complex Regulates Kif2A Localization to Ensure Chromosome Congression and Proper Spindle Assembly during Mitosis.

Science.gov (United States)

Ali, Aamir; Veeranki, Sailaja Naga; Chinchole, Akash; Tyagi, Shweta

2017-06-19

Mixed-lineage leukemia (MLL), along with multisubunit (WDR5, RbBP5, ASH2L, and DPY30) complex catalyzes the trimethylation of H3K4, leading to gene activation. Here, we characterize a chromatin-independent role for MLL during mitosis. MLL and WDR5 localize to the mitotic spindle apparatus, and loss of function of MLL complex by RNAi results in defects in chromosome congression and compromised spindle formation. We report interaction of MLL complex with several kinesin and dynein motors. We further show that the MLL complex associates with Kif2A, a member of the Kinesin-13 family of microtubule depolymerase, and regulates the spindle localization of Kif2A during mitosis. We have identified a conserved WDR5 interaction (Win) motif, so far unique to the MLL family, in Kif2A. The Win motif of Kif2A engages in direct interactions with WDR5 for its spindle localization. Our findings highlight a non-canonical mitotic function of MLL complex, which may have a direct impact on chromosomal stability, frequently compromised in cancer. Copyright © 2017 Elsevier Inc. All rights reserved.

Chromosome abnormalities in atomic bomb survivors

International Nuclear Information System (INIS)

Tomonaga, Yu

1976-01-01

Chromosome abnormalities in bone marrow cells were recognized in 6 cases which consisted of one case of chronic myelogenous leukemia, two cases of acute myelogenous leukemia, one case of sideroblastic anemia, and two cases of myelodysplasis. Frequency of stable type chromosome abnormalities in bone marrow cells was investigated in 45 atomic bomb survivors without hematologic disorders and 15 controls. It was 1.4% (15 cases) in the group exposed to atomic bomb within 1 km from the hypocenter, which was significantly higher as compared with 0.1% (15 cases) in the group exposed to atomic bomb over 2.5 km from the hypocenter and 0.2% in normal controls. Examination of chromosome was also made on 2 of 3 cases which were the seconds born of female with high chromosome abnormality, who was exposed to within 1 km from the hypocenter, and healthy male exposed 3 km from the hypocenter. These two cases showed chromosome of normal male type, and balanced translocation was not recognized. There was not a significant difference in chromosome abnormalities between the seconds of atomic bomb survivors and controls. (Kanao, N.)

[Origin and morphological features of small supernumerary marker chromosomes in Turner syndrome].

Science.gov (United States)

Liu, Nan; Tong, Tong; Chen, Yue; Chen, Yanling; Cai, Chunquan

2018-02-10

OBJECTIVE To explore the origin and morphological features of small supernumerary marker chromosomes (sSMCs) in Turner syndrome. METHODS For 5 cases of Turner syndrome with a sSMC identified by conventional G-banding, dual-color fluorescence in situ hybridization (FISH) was applied to explore their origin and morphological features. RESULTS Among the 5 cases, 3 have derived from the X chromosome, which included 2 ring chromosomes and 1 centric minute. For the 2 sSMCs derived from the Y chromosome, 1 was ring or isodicentric chromosome, while the other was an isodicentric chromosome. CONCLUSION The sSMCs found in Turner syndrome have almost all derived from sex chromosomes. The majority of sSMCs derived from the X chromosome will form ring chromosomes, while a minority will form centric minute. While most sSMC derived from Y chromosome may exist as isodicentric chromosomes, and a small number may exist as rings. For Turner syndrome patients with sSMCs, dual-color FISH may be used to delineate their origins to facilitate genetic counseling and selection of clinical regime.

Sequencing chromosome 5D of Aegilops tauschii and comparison with its allopolyploid descendant bread wheat (Triticum aestivum)

Czech Academy of Sciences Publication Activity Database

Akpinar, B. A.; Lucas, S. J.; Vrána, Jan; Doležel, Jaroslav; Budak, H.

2015-01-01

Roč. 13, č. 6 (2015), s. 740-752 ISSN 1467-7644 R&D Projects: GA ČR GBP501/12/G090; GA MŠk(CZ) LO1204 Institutional support: RVO:61389030 Keywords : D genome donor of wheat * chromosome 5D * comparative genomics Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 6.090, year: 2015

HTR1A a novel type 1 diabetes susceptibility gene on chromosome 5p13-q13

DEFF Research Database (Denmark)

Asad, Samina; Nikamo, Pernilla; Gyllenberg, Alexandra

2012-01-01

We have previously performed a genome-wide linkage study in Scandinavian Type 1 diabetes (T1D) families. In the Swedish families, we detected suggestive linkage (LOD≤2.2) to the chromosome 5p13-q13 region. The aim of our study was to investigate the linked region in search for possible T1D...

Chromosomal aberration

International Nuclear Information System (INIS)

Ishii, Yutaka

1988-01-01

Chromosomal aberrations are classified into two types, chromosome-type and chromatid-type. Chromosom-type aberrations include terminal deletion, dicentric, ring and interstitial deletion, and chromatid-type aberrations include achromatic lesion, chromatid deletion, isochromatid deletion and chromatid exchange. Clastogens which induce chromosomal aberration are divided into ''S-dependent'' agents and ''S-independent''. It might mean whether they can induce double strand breaks independent of the S phase or not. Double strand breaks may be the ultimate lesions to induce chromosomal aberrations. Caffeine added even in the G 2 phase appeared to modify the frequency of chromatid aberrations induced by X-rays and mitomycin C. Those might suggest that the G 2 phase involves in the chromatid aberration formation. The double strand breaks might be repaired by ''G 2 repair system'', the error of which might yield breakage types of chromatid aberrations and the by-pass of which might yield chromatid exchanges. Chromosome-type aberrations might be formed in the G 1 phase. (author)

Elimination of nonspecific radioactivity from [{sup 76}Br]bromide in PET study with [{sup 76}Br]bromodeoxyuridine

Energy Technology Data Exchange (ETDEWEB)

Li Lu; Bergstroem, Mats E-mail: Mats.Bergstroem@pet.uu.se; Fasth, Karl-Johan; Wu Feng; Eriksson, Barbro; Laangstroem, Bengt

1999-10-01

[{sup 76}Br]Bromodeoxyuridine ([{sup 76}Br]BrdU) might allow a determination of proliferation in vivo using positron emission tomography (PET), but only with consideration of organ nonspecific radioactivity constituted by [{sup 76}Br]bromide. A first study assessed the potential of diuretics to eliminate [{sup 76}Br]bromide. [{sup 76}Br]Bromide was injected in the vein of rats and different diuretic combinations were given. Urine was collected and radioactivity measured. Torasemide plus sodium chloride gave better {sup 76}Br elimination than the other diuretics. In a second experiment, rats were given [{sup 76}Br]BrdU. After the radioactivity injection, the rats of the treatment group were given torasemide plus NaCl. At 44 h after the radioactivity injection, the radioactivity concentration and the fraction incorporated into DNA were measured in different organs. Using diuretics, the elimination of [{sup 76}Br]bromide was increased. The radioactivity decreased 30-50% in most of the organs but the highest radioactivity uptake was found in the organs with more active DNA synthesis. This method may facilitate the use of [{sup 76}Br]BrdU as a tracer for DNA synthesis using PET.

Tumour radiosensitization with the halogenated pyrimidines 5'-bromo-and 5'-iododeoxyuridine

International Nuclear Information System (INIS)

Epstein, A.H.; Cook, J.A.; Goffman, T.; Glatstein, E.

1993-01-01

The authors review studies of the use of iododeoxyuridine (IdUrd) and bromodeoxyuridine as radiosensitizers and attempt to correlate the clinical outcome for patients treated with radiation and IdUrd with the extent of halogenated pyrimidine cellular uptake and incorporation. (U.K.)

Functional Identification of the Plasmodium Centromere and Generation of a Plasmodium Artificial Chromosome

OpenAIRE

Iwanaga, Shiroh; Khan, Shahid M.; Kaneko, Izumi; Christodoulou, Zoe; Newbold, Chris; Yuda, Masao; Janse, Chris J.; Waters, Andrew P.

2010-01-01

Summary The artificial chromosome represents a useful tool for gene transfer, both as cloning vectors and in chromosome biology research. To generate a Plasmodium artificial chromosome (PAC), we had to first functionally identify and characterize the parasite's centromere. A putative centromere (pbcen5) was cloned from chromosome 5 of the rodent parasite P. berghei based on a Plasmodium gene-synteny map. Plasmids containing pbcen5 were stably maintained in parasites during a blood-stage infec...

Opposite replication polarities of transcribed and nontranscribed histone H5 genes

International Nuclear Information System (INIS)

Trempe, J.P.; Lindstrom, Y.I.; Leffak, M.

1988-01-01

The authors used an in vitro nuclear runoff replication assay to analyze the direction of replication of the active and inactive histone H5 genes in avian cells. In embryonic erythrocytes the transcribed histone H5 gene displayed sensitivity to endogenous nuclease cleavage. In contrast, this gene was insensitive to endogenous nuclease digestion under the same conditions in nuclei of the lymphoblastoid cell line MSB-1, and histone H5 gene transcripts were not detectable by dot-blot analysis of MSB-1 cell RNA. When nuclei were isolated from embryonic erythrocyctes and incubated with bromodeoxyuridine triphosphate, runoff replication from endogenous nuclease cleavage sites led to a relative enrichment for fragments near the 3' end of the histone H5 gene in the density-labeled DNA. In nuclei of MSB-1 cells or chicken embryo fibroblasts, however, runoff replication from restriction enzyme-cut sites (or induced endogenous nuclease-cut sites in MSB-1 nuclei) led to a relative enrichment for fragments near the 5' end of the H5 gene in dense DNA. Based on the enhanced incorporation of bromodeoxyuridine into origin-distal regions of DNA during the in vitro runoff replication assay, the authors conclude that the active histone H5 gene in embryonic erythrocytes is preferentially replicated in the transcriptional direction from an origin in the 5'-flanking DNA, whereas its inactive counterparts in MSB-1 cells and chicken embryo fibroblasts are preferentially replicated in the opposite direction

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.

Development of a quantitative pachytene chromosome map and its unification with somatic chromosome and linkage maps of rice (Oryza sativa L.).

Science.gov (United States)

Ohmido, Nobuko; Iwata, Aiko; Kato, Seiji; Wako, Toshiyuki; Fukui, Kiichi

2018-01-01

A quantitative pachytene chromosome map of rice (Oryza sativa L.) was developed using imaging methods. The map depicts not only distribution patterns of chromomeres specific to pachytene chromosomes, but also the higher order information of chromosomal structures, such as heterochromatin (condensed regions), euchromatin (decondensed regions), the primary constrictions (centromeres), and the secondary constriction (nucleolar organizing regions, NOR). These features were image analyzed and quantitatively mapped onto the map by Chromosome Image Analyzing System ver. 4.0 (CHIAS IV). Correlation between H3K9me2, an epigenetic marker and formation and/or maintenance of heterochromatin, thus was, clearly visualized. Then the pachytene chromosome map was unified with the existing somatic chromosome and linkage maps by physically mapping common DNA markers among them, such as a rice A genome specific tandem repeat sequence (TrsA), 5S and 45S ribosomal RNA genes, five bacterial artificial chromosome (BAC) clones, four P1 bacteriophage artificial chromosome (PAC) clones using multicolor fluorescence in situ hybridization (FISH). Detailed comparison between the locations of the DNA probes on the pachytene chromosomes using multicolor FISH, and the linkage map enabled determination of the chromosome number and short/long arms of individual pachytene chromosomes using the chromosome number and arm assignment designated for the linkage map. As a result, the quantitative pachytene chromosome map was unified with two other major rice chromosome maps representing somatic prometaphase chromosomes and genetic linkages. In conclusion, the unification of the three rice maps serves as an indispensable basic information, not only for an in-depth comparison between genetic and chromosomal data, but also for practical breeding programs.

Radiation induced wheat-rye chromosomal translocations in triticale. Optimizing the dose using fluorescence in situ hybridization

International Nuclear Information System (INIS)

Ahmad, F.; Comeau, A.; Chen, Q.; Collin, J.; St-Pierre, C.A.

2000-01-01

Fluorescent in situ hybridization (FISH) was utilized to monitor the level of ionizing radiation ( 60 Co source) in their ability to cause intra- and intergeneric chromosomal aberrations in triticale seeds. Seeds were irradiated with 0, 20, 50, 100, 200, 300, 400, 500 and 1000 Gy doses. The root growth of irradiated seeds was greatly inhibited at 200 Gy and above. Various types of aberrations including wheat-rye, wheat-wheat, rye-rye, wheat-rye-wheat, rye-wheat-rye translocations and acentric fragments with or without translocations were observed. There was a consistent increase in proportion of aberrations per cell with an increase in radiation dose. It was concluded that for an optimal level of chromosomal translocation and least number of acentric fragments, a 20 Gy dose was quite sufficient for inducing a desirable level of wheat-rye chromosomal translocations. The excellent efficiency and importance of utilizing FISH in such studies of alien-introgression via chromosomal translocations are discussed. (author)

Radiation induced wheat-rye chromosomal translocations in triticale. Optimizing the dose using fluorescence in situ hybridization

Energy Technology Data Exchange (ETDEWEB)

Ahmad, F. [Brandon Univ., Manitoba (Canada); Comeau, A.; Chen, Q.; Collin, J.; St-Pierre, C.A.

2000-03-01

Fluorescent in situ hybridization (FISH) was utilized to monitor the level of ionizing radiation ({sup 60}Co source) in their ability to cause intra- and intergeneric chromosomal aberrations in triticale seeds. Seeds were irradiated with 0, 20, 50, 100, 200, 300, 400, 500 and 1000 Gy doses. The root growth of irradiated seeds was greatly inhibited at 200 Gy and above. Various types of aberrations including wheat-rye, wheat-wheat, rye-rye, wheat-rye-wheat, rye-wheat-rye translocations and acentric fragments with or without translocations were observed. There was a consistent increase in proportion of aberrations per cell with an increase in radiation dose. It was concluded that for an optimal level of chromosomal translocation and least number of acentric fragments, a 20 Gy dose was quite sufficient for inducing a desirable level of wheat-rye chromosomal translocations. The excellent efficiency and importance of utilizing FISH in such studies of alien-introgression via chromosomal translocations are discussed. (author)

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.

Prenatal chromosomal microarray analysis in fetuses with congenital heart disease: a prospective cohort study.

Science.gov (United States)

Wang, Yan; Cao, Li; Liang, Dong; Meng, Lulu; Wu, Yun; Qiao, Fengchang; Ji, Xiuqing; Luo, Chunyu; Zhang, Jingjing; Xu, Tianhui; Yu, Bin; Wang, Leilei; Wang, Ting; Pan, Qiong; Ma, Dingyuan; Hu, Ping; Xu, Zhengfeng

2018-02-01

Currently, chromosomal microarray analysis is considered the first-tier test in pediatric care and prenatal diagnosis. However, the diagnostic yield of chromosomal microarray analysis for prenatal diagnosis of congenital heart disease has not been evaluated based on a large cohort. Our aim was to evaluate the clinical utility of chromosomal microarray as the first-tier test for chromosomal abnormalities in fetuses with congenital heart disease. In this prospective study, 602 prenatal cases of congenital heart disease were investigated using single nucleotide polymorphism array over a 5-year period. Overall, pathogenic chromosomal abnormalities were identified in 125 (20.8%) of 602 prenatal cases of congenital heart disease, with 52.0% of them being numerical chromosomal abnormalities. The detection rates of likely pathogenic copy number variations and variants of uncertain significance were 1.3% and 6.0%, respectively. The detection rate of pathogenic chromosomal abnormalities in congenital heart disease plus additional structural anomalies (48.9% vs 14.3%, P congenital heart disease group. Additionally, the detection rate in congenital heart disease with additional structural anomalies group was significantly higher than that in congenital heart disease with soft markers group (48.9% vs 19.8%, P congenital heart disease with additional structural anomalies and congenital heart disease with intrauterine growth retardation groups (48.9% vs 50.0%), congenital heart disease with soft markers and congenital heart disease with intrauterine growth retardation groups (19.8% vs 50.0%), or congenital heart disease with soft markers and isolated congenital heart disease groups (19.8% vs 14.3%). The detection rate in fetuses with congenital heart disease plus mild ventriculomegaly was significantly higher than in those with other types of soft markers (50.0% vs 15.6%, P congenital heart disease in clinical practice. Copyright © 2017 Elsevier Inc. All rights reserved.

Cytogenetic and genetic studies of radiation-induced chromosome damage in mouse oocytes. Part 1. Numerical and structural chromosome anomalies in metaphase II oocytes, pre- and post-implantation embryos

International Nuclear Information System (INIS)

Tease, Charles; Fisher, Graham

1996-01-01

The incidences of X-ray induced numerical and structural chromosome anomalies were screened in a range of developmental stages from metaphase II oocytes through to post-implantation embryos. Following 1 Gy of acute X-rays to immediately preovulatory stage oocytes, the rate of hyperploidy (chromosome gain) was found to be elevated over levels in unirradiated controls, at metaphase II, in 1-cell and 3.5 day pre-implantation embryos but not in 8.5 day post-implantation foetuses. In the latter, however, the frequency of mosaicism was significantly increased. A similar response of an increase in mosaicism but not in hyperploidy in 8.5 day post-implantation embryos was also found after irradiation of dictyate stage oocytes with 4 Gy of acute X-rays. Significantly elevated frequencies of structural chromosome anomalies were present in metaphase II oocytes and pre-implantation embryonic stages, but could not be detected in block-stained chromosome preparations from 8.5 day post-implantation foetuses. However, analysis of chromosome preparations after G-banding showed that almost 14% of 14.5 day foetuses carried a chromosome rearrangement after 1 Gy of X-rays to immediately preovulatory stage oocytes. Overall, our data indicate that the presence of radiation-induced chromosome gains are incompatible with embryonic survival but that a proportion of embryos with structural chromosome damage develop past mid-gestation. These latter embryos are therefore potentially capable of contributing to the genetic burden of the next generation

Slit scan flow cytometry of isolated chromosomes following fluorescence hybridization: an approach of online screening for specific chromosomes and chromosome translocations

NARCIS (Netherlands)

Hausmann, M.; Dudin, G.; Aten, J. A.; Heilig, R.; Diaz, E.; Cremer, C.

1991-01-01

The recently developed methods of non radioactive in situ hybridization of chromosomes offer new aspects for chromosome analysis. Fluorescent labelling of hybridized chromosomes or chromosomal subregions allows to facilitate considerably the detection of specific chromosomal abnormalities. For many

Evolutionary rate of a gene affected by chromosomal position.

Science.gov (United States)

Perry, J; Ashworth, A

1999-09-09

Genes evolve at different rates depending on the strength of selective pressure to maintain their function. Chromosomal position can also have an influence [1] [2]. The pseudoautosomal region (PAR) of mammalian sex chromosomes is a small region of sequence identity that is the site of an obligatory pairing and recombination event between the X and Y chromosomes during male meiosis [3] [4] [5] [6]. During female meiosis, X chromosomes can pair and recombine along their entire length. Recombination in the PAR is therefore approximately 10 times greater in male meiosis compared with female meiosis [4] [5] [6]. The gene Fxy (also known as MID1 [7]) spans the pseudoautosomal boundary (PAB) in the laboratory mouse (Mus musculus domesticus, C57BL/6) such that the 5' three exons of the gene are located on the X chromosome but the seven exons encoding the carboxy-terminal two-thirds of the protein are located within the PAR and are therefore present on both the X and Y chromosomes [8]. In humans [7] [9], the rat, and the wild mouse species Mus spretus, the gene is entirely X-unique. Here, we report that the rate of sequence divergence of the 3' end of the Fxy gene is much higher (estimated at 170-fold higher for synonymous sites) when pseudoautosomal (present on both the X and Y chromosomes) than when X-unique. Thus, chromosomal position can directly affect the rate of evolution of a gene. This finding also provides support for the suggestion that regions of the genome with a high recombination frequency, such as the PAR, may have an intrinsically elevated rate of sequence divergence.

Overexpression of eIF-5A2 in mice causes accelerated organismal aging by increasing chromosome instability

Directory of Open Access Journals (Sweden)

Chen Leilei

2011-05-01

Full Text Available Abstract Background Amplification of 3q26 is one of the most frequent genetic alterations in many human malignancies. Recently, we isolated a novel oncogene eIF-5A2 within the 3q26 region. Functional study has demonstrated the oncogenic role of eIF-5A2 in the initiation and progression of human cancers. In the present study, we aim to investigate the physiological and pathological effect of eIF-5A2 in an eIF-5A2 transgenic mouse model. Methods An eIF-5A2 transgenic mouse model was generated using human eIF-5A2 cDNA. The eIF-5A2 transgenic mice were characterized by histological and immunohistochemistry analyses. The aging phenotypes were further characterized by wound healing, bone X-ray imaging and calcification analysis. Mouse embryo fibroblasts (MEF were isolated to further investigate molecular mechanism of eIF-5A2 in aging. Results Instead of resulting in spontaneous tumor formation, overexpression of eIF-5A2 accelerated the aging process in adult transgenic mice. This included decreased growth rate and body weight, shortened life span, kyphosis, osteoporosis, delay of wound healing and ossification. Investigation of the correlation between cellular senescence and aging showed that cellular senescence is not required for the aging phenotypes in eIF-5A2 mice. Interestingly, we found that activation of eIF-5A2 repressed p19 level and therefore destabilized p53 in transgenic mouse embryo fibroblast (MEF cells. This subsequently allowed for the accumulation of chromosomal instability, such as errors in cell dividing during metaphase and anaphase. Additionally, a significantly increase in number of aneuploidy cells (p Conclusion These observations suggest that eIF-5A2 mouse models could accelerate organismal aging by increasing chromosome instability.

Absence of methylation of a CpG-rich region at the 5' end of the MIC2 gene on the active X, the inactive X, and the Y chromosome

International Nuclear Information System (INIS)

Goodfellow, P.J.; Mondello, C.; Darling, S.M.; Pym, B.; Little, P.; Goodfellow, P.N.

1988-01-01

The authors have identified and characterized a Hpa II tiny fragment (HTF) island associated with the promoter region of the pseudoautosomal gene MIC2. The MIC2 HTF island is unmethylated on both the active and inactive X chromosome and is similarly unmethylated on the Y chromosome. Unlike the majority of genes borne on the X chromosome, MIC2 fails to undergo X chromosome inactivation. HTF islands associated with X chromosome-liked genes that are inactivated are highly methylated on the inactive or transcriptionally silent homologue. The failure of MIC2 to undergo X chromosome inactivation correlates with the lack of methylation of HTF island at the 5' end of the gene. These results provide further evidence that DNA methylation plays an important role in the phenomenon of X chromosome inactivation

Meiotic Chromosome Analysis of the Giant Water Bug, Lethocerus indicus

Science.gov (United States)

Wisoram, Wijit; Saengthong, Pradit; Ngernsiri, Lertluk

2013-01-01

The giant water bug, Lethocerus indicus (Lepeletier and Serville) (Heteroptera: Belostomatidae), a native species of Southeast Asia, is one of the largest insects belonging to suborder Heteroptera. In this study, the meiotic chromosome of L. indicus was studied in insect samples collected from Thailand, Myanmar, Loas, and Cambodia. Testicular cells stained with lacto-acetic orcein, Giemsa, DAPI, and silver nitrate were analyzed. The results revealed that the chromosome complement of L. indicus was 2n = 22A + neo-XY + 2m, which differed from that of previous reports. Each individual male contained testicular cells with three univalent patterns. The frequency of cells containing neo-XY chromosome univalent (∼5%) was a bit higher than that of cells with autosomal univalents (∼3%). Some cells (∼0.5%) had both sex chromosome univalents and a pair of autosomal univalents. None of the m-chromosome univalents were observed during prophase I. In addition, this report presents clear evidence about the existence of m-chromosomes in Belostomatidae. PMID:23895100

Chromosomal abnormality in patients with secondary amenorrhea.

Science.gov (United States)

Safai, Akbar; Vasei, Mohammad; Attaranzadeh, Armin; Azad, Fariborz; Tabibi, Narjes

2012-04-01

Secondary amenorrhea is a condition in which there is cessation of menses after at least one menstruation. It is a symptom of different diseases, such as hormonal disturbances which range from pituitary to ovarian origin, as well as chromosomal abnormalities. Knowledge of the distinct cause of secondary amenorrhea is of tremendous benefit for the management and monitoring of patients. In this study, we determine the chromosomal abnormalities in patients with secondary amenorrhea in Southwest Iran. We selected 94 patients with secondary amenorrhea who referred to our Cytogenetic Ward from 2004 until 2009. For karyotyping, peripheral blood lymphocyte cultures were set up by conventional technique. In this study, 5.3% (n=5) of patients with secondary amenorrhea presented with chromosomal abnormalities, of which all contained an X element. The chromosomal abnormalities were: i) 45, X (n=1); ii) 47, XXX (n=1); iii) 45, X [13]/ 45, Xi(X)q[17] (n=1);  iv) 45, X[12]/46,X,+mar[12] (n=1); and v) 46,X,del(Xq)(q23q28) (n=1). Our study revealed that some causes of secondary amenorrhea could be due to chromosomal abnormalities. Therefore, cytogenetic studies should be important tests in the evaluation of patients with secondary amenorrhea.

Comparing and transforming PROMIS utility values to the EQ-5D.

Science.gov (United States)

Hartman, John D; Craig, Benjamin M

2018-03-01

Summarizing patient-reported outcomes (PROs) on a quality-adjusted life year (QALY) scale is an essential component to any economic evaluation comparing alternative medical treatments. While multiple studies have compared PRO items and instruments based on their psychometric properties, no study has compared the preference-based summary of the EQ-5D-3L and Patient Reported Outcomes Measurement Information System (PROMIS-29) instruments. As part of this comparison, a major aim of this manuscript is to transform PROMIS-29 utility values to an EQ-5D-3L scale. A nationally representative survey of 2623 US adults completed the 29-item PROMIS health profile instrument (PROMIS-29) and the 3-level version of the EQ-5D instrument (EQ-5D-3L). Their responses were summarized on a health utility scale using published estimates. Using regression analysis, PROMIS-29 and EQ-5D-3L utility weights were compared with each other as well as with self-reported general health. PROMIS-29 utility weights were much lower than the EQ-5D-3L weights. However, a correlation coefficient of 0.769 between the utility values of the two instruments suggests that the main discordance is simply a difference in scale between the measures. It is also possible to map PROMIS-29 utility weights onto an EQ-5D-3L scale. EQ-5D-3L losses equal .1784 × (PROMIS-29 Losses) .7286 . The published estimates of the PROMIS-29 produce lower utility values than many other health instruments. Mapping the PROMIS-29 estimates to an EQ-5D-3L scale alleviates this issue and allows for a more straightforward comparison between the PROMIS-29 and other common health instruments.

Truncated ALK derived from chromosomal translocation t(2;5)(p23;q35) binds to the SH3 domain of p85-PI3K.

Science.gov (United States)

Polgar, Doris; Leisser, Christina; Maier, Susanne; Strasser, Stephan; Rüger, Beate; Dettke, Markus; Khorchide, Maya; Simonitsch, Ingrid; Cerni, Christa; Krupitza, Georg

2005-02-15

The chromosomal translocation t(2;5)(p23;q35) is associated with "Anaplastic large cell lymphomas" (ALCL), a Non Hodgkin Lymphoma occurring in childhood. The fusion of the tyrosine kinase gene-ALK (anaplastic lymphoma kinase) on chromosome 2p23 to the NPM (nucleophosmin/B23) gene on chromosome 5q35 results in a 80 kDa chimeric protein, which activates the "survival" kinase PI3K. However, the binding mechanism between truncated ALK and PI3K is poorly understood. Therefore, we attempted to elucidate the molecular interaction between ALK and the regulatory p85 subunit of PI3K. Here we provide evidence that the truncated ALK homodimer binds to the SH3 domain of p85. This finding may be useful for the development of a new target-specific intervention.

Assignment of the 5HT7 receptor gene (HTR7) to chromosome 10q and exclusion of genetic linkage with Tourette syndrome

Energy Technology Data Exchange (ETDEWEB)

Gelernter, J.; Rao, P.A.; Pauls, D.L. [Yale Univ. School of Medicine, West Haven, CT (United States)] [and others

1995-03-20

A novel serotonin receptor designated 5HT7 (genetic locus HTR7) was cloned in 1993. This receptor has interesting properties related to ligand affinity and CNS distribution that render HTR7 a very interesting candidate gene for neuropsychiatric disorders. We mapped this gene, first by physical methods and then by genetic linkage. First, we made a tentative assignment to chromosome 10, based on hybridization of an HTR7 probe to a Southern blot of DNA from somatic cell hybrids. We then identified a genetic polymorphism at the HTR7 locus. We identified one extended pedigree where the polymorphism segregated. Using the LEPED computer program for pairwise linkage analysis, we confirmed the assignment of the gene to chromosome 10, specifically 10q21-q24, based on a lod score of 5.37 at 0% recombination between HTR7 and D10S20 (a chromosome 10 reference marker). Finally, we excluded genetic linkage between this locus and Tourette syndrome under a reasonable set of assumptions. 15 refs., 1 fig., 1 tab.

Unprecedented large inverted repeats at the replication terminus of circular bacterial chromosomes suggest a novel mode of chromosome rescue

Science.gov (United States)

El Kafsi, Hela; Loux, Valentin; Mariadassou, Mahendra; Blin, Camille; Chiapello, Hélène; Abraham, Anne-Laure; Maguin, Emmanuelle; van de Guchte, Maarten

2017-01-01

The first Lactobacillus delbrueckii ssp. bulgaricus genome sequence revealed the presence of a very large inverted repeat (IR), a DNA sequence arrangement which thus far seemed inconceivable in a non-manipulated circular bacterial chromosome, at the replication terminus. This intriguing observation prompted us to investigate if similar IRs could be found in other bacteria. IRs with sizes varying from 38 to 76 kbp were found at the replication terminus of all 5 L. delbrueckii ssp. bulgaricus chromosomes analysed, but in none of 1373 other chromosomes. They represent the first naturally occurring very large IRs detected in circular bacterial genomes. A comparison of the L. bulgaricus replication terminus regions and the corresponding regions without IR in 5 L. delbrueckii ssp. lactis genomes leads us to propose a model for the formation and evolution of the IRs. The DNA sequence data are consistent with a novel model of chromosome rescue after premature replication termination or irreversible chromosome damage near the replication terminus, involving mechanisms analogous to those proposed in the formation of very large IRs in human cancer cells. We postulate that the L. delbrueckii ssp. bulgaricus-specific IRs in different strains derive from a single ancestral IR of at least 93 kbp. PMID:28281695

DNA amount of X and B chromosomes in the grasshoppers Eyprepocnemis plorans and Locusta migratoria.

Science.gov (United States)

Ruiz-Ruano, F J; Ruiz-Estévez, M; Rodríguez-Pérez, J; López-Pino, J L; Cabrero, J; Camacho, J P M

2011-01-01

We analyzed the DNA amount in X and B chromosomes of 2 XX/X0 grasshopper species (Eyprepocnemis plorans and Locusta migratoria), by means of Feulgen image analysis densitometry (FIAD), using previous estimates in L. migratoria as standard (5.89 pg). We first analyzed spermatids of 0B males and found a bimodal distribution of integrated optical densities (IODs), suggesting that one peak corresponded to +X and the other to -X spermatids. The difference between the 2 peaks corresponded to the X chromosome DNA amount, which was 1.28 pg in E. plorans and 0.80 pg in L. migratoria. In addition, the +X peak in E. plorans gave an estimate of the C-value in this species (10.39 pg). We next analyzed diplotene cells from 1B males in E. plorans and +B males in L. migratoria (a species where Bs are mitotically unstable and no integer B number can be defined for an individual) and measured B chromosome IOD relative to X chromosome IOD, within the same cell, taking advantage of the similar degree of condensation for both positively heteropycnotic chromosomes at this meiotic stage. From this proportion, we estimated the DNA amount for 3 different B chromosome variants found in individuals from 3 E. plorans Spanish populations (0.54 pg for B1 from Saladares, 0.51 pg for B2 from Salobreña and 0.64 for B24 from Torrox). Likewise, we estimated the DNA amount of the B chromosome in L. migratoria to be 0.15 pg. To automate measurements, we wrote a GPL3 licensed Python program (pyFIA). We discuss the utility of the present approach for estimating X and B chromosome DNA amount in a variety of situations, and the meaning of the DNA amount estimates for X and B chromosomes in these 2 species. Copyright © 2011 S. Karger AG, Basel.

Chromosomal Abnormalities Associated With Omphalocele

Directory of Open Access Journals (Sweden)

Chih-Ping Chen

2007-03-01

Full Text Available Fetuses with omphalocele have an increased risk for chromosomal abnormalities. The risk varies with maternal age, gestational age at diagnosis, association with umbilical cord cysts, complexity of associated anomalies, and the contents of omphalocele. There is considerable evidence that genetics contributes to the etiology of omphalocele. This article provides an overview of chromosomal abnormalities associated with omphalocele and a comprehensive review of associated full aneuploidy such as trisomy 18, trisomy 13, triploidy, trisomy 21, 45,X, 47,XXY, and 47,XXX, partial aneuploidy such as dup(3q, dup(11p, inv(11, dup(1q, del(1q, dup(4q, dup(5p, dup(6q, del(9p, dup(15q, dup(17q, Pallister-Killian syndrome with mosaic tetrasomy 12p and Miller-Dieker lissencephaly syndrome with deletion of 17p13.3, and uniparental disomy (UPD such as UPD 11 and UPD 14. Omphalocele is a prominent marker for chromosomal abnormalities. Perinatal identification of omphalocele should alert chromosomal abnormalities and familial unbalanced translocations, and prompt thorough cytogenetic investigations and genetic counseling.

8987Array-Chromosome - RMOS | LSDB Archive [Life Science Database Archive metadata

Lifescience Database Archive (English)

Full Text Available List Contact us RMOS 8987Array-Chromosome Data detail Data name 8987Array-Chromosome DOI 10.18908/lsdba.nbdc...00194-008 Description of data contents Position information of the clone of Rice8987 Array (f_array) on chromoso...mes Data file File name: rmos_8987array_chromosome.csv.zip File URL: ftp://ftp.biosciencedbc.jp/archive/...rmos/LATEST/rmos_8987array_chromosome.csv.zip File size: 96.5 KB Simple search UR...L http://togodb.biosciencedbc.jp/togodb/view/rmos_8987array_chromosome#en Data acquisition method - Data ana

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

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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.

Admixture mapping of 15,280 African Americans identifies obesity susceptibility loci on chromosomes 5 and X.

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Ching-Yu Cheng

2009-05-01

Full Text Available The prevalence of obesity (body mass index (BMI > or =30 kg/m(2 is higher in African Americans than in European Americans, even after adjustment for socioeconomic factors, suggesting that genetic factors may explain some of the difference. To identify genetic loci influencing BMI, we carried out a pooled analysis of genome-wide admixture mapping scans in 15,280 African Americans from 14 epidemiologic studies. Samples were genotyped at a median of 1,411 ancestry-informative markers. After adjusting for age, sex, and study, BMI was analyzed both as a dichotomized (top 20% versus bottom 20% and a continuous trait. We found that a higher percentage of European ancestry was significantly correlated with lower BMI (rho = -0.042, P = 1.6x10(-7. In the dichotomized analysis, we detected two loci on chromosome X as associated with increased African ancestry: the first at Xq25 (locus-specific LOD = 5.94; genome-wide score = 3.22; case-control Z = -3.94; and the second at Xq13.1 (locus-specific LOD = 2.22; case-control Z = -4.62. Quantitative analysis identified a third locus at 5q13.3 where higher BMI was highly significantly associated with greater European ancestry (locus-specific LOD = 6.27; genome-wide score = 3.46. Further mapping studies with dense sets of markers will be necessary to identify the alleles in these regions of chromosomes X and 5 that may be associated with variation in BMI.

Resolution and evolution of the duck-billed platypus karyotype with an X1Y1X2Y2X3Y3X4Y4X5Y5 male sex chromosome constitution.

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Rens, Willem; Grützner, Frank; O'brien, Patricia C M; Fairclough, Helen; Graves, Jennifer A M; Ferguson-Smith, Malcolm A

2004-11-16

The platypus (2n = 52) has a complex karyotype that has been controversial over the last three decades. The presence of unpaired chromosomes and an unknown sex-determining system especially has defied attempts at conventional analysis. This article reports on the preparation of chromosome-specific probes from flow-sorted chromosomes and their application in the identification and classification of all platypus chromosomes. This work reveals that the male karyotype has 21 pairs of chromosomes and 10 unpaired chromosomes (E1-E10), which are linked by short regions of homology to form a multivalent chain in meiosis. The female karyotype differs in that five of these unpaired elements (E1, E3, E5, E7, and E9) are each present in duplicate, whereas the remaining five unpaired elements (E2, E4, E6, E8, and E10) are absent. This finding indicates that sex is determined by the alternate segregation of the chain of 10 during spermatogenesis so that equal numbers of sperm bear either one of the two groups of five elements, i.e., five X and five Y chromosomes. Chromosome painting reveals that these X and Y chromosomes contain pairing (XY shared) and differential (X- or Y-specific) segments. Y differential regions must contain male-determining genes, and X differential regions should be dosage-compensated in the female. Two models for the evolution of the sex-determining system are presented. The resolution of the longstanding debate over the platypus karyotype is an important step toward the understanding of mechanisms of sex determination, dosage compensation, and karyotype evolution.

Molecular evolution of a Y chromosome to autosome gene duplication in Drosophila.

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Dyer, Kelly A; White, Brooke E; Bray, Michael J; Piqué, Daniel G; Betancourt, Andrea J

2011-03-01

In contrast to the rest of the genome, the Y chromosome is restricted to males and lacks recombination. As a result, Y chromosomes are unable to respond efficiently to selection, and newly formed Y chromosomes degenerate until few genes remain. The rapid loss of genes from newly formed Y chromosomes has been well studied, but gene loss from highly degenerate Y chromosomes has only recently received attention. Here, we identify and characterize a Y to autosome duplication of the male fertility gene kl-5 that occurred during the evolution of the testacea group species of Drosophila. The duplication was likely DNA based, as other Y-linked genes remain on the Y chromosome, the locations of introns are conserved, and expression analyses suggest that regulatory elements remain linked. Genetic mapping reveals that the autosomal copy of kl-5 resides on the dot chromosome, a tiny autosome with strongly suppressed recombination. Molecular evolutionary analyses show that autosomal copies of kl-5 have reduced polymorphism and little recombination. Importantly, the rate of protein evolution of kl-5 has increased significantly in lineages where it is on the dot versus Y linked. Further analyses suggest this pattern is a consequence of relaxed purifying selection, rather than adaptive evolution. Thus, although the initial fixation of the kl-5 duplication may have been advantageous, slightly deleterious mutations have accumulated in the dot-linked copies of kl-5 faster than in the Y-linked copies. Because the dot chromosome contains seven times more genes than the Y and is exposed to selection in both males and females, these results suggest that the dot suffers the deleterious effects of genetic linkage to more selective targets compared with the Y chromosome. Thus, a highly degenerate Y chromosome may not be the worst environment in the genome, as is generally thought, but may in fact be protected from the accumulation of deleterious mutations relative to other nonrecombining

Chromosomal insertion of the entire Escherichia coli lactose operon, into two strains of Pseudomonas, using a modified mini-Tn5 delivery system

DEFF Research Database (Denmark)

Hansen, L. H.; Sørensen, S. J.; Jensen, Lars Bogø

1997-01-01

A 12-kb PstI fragment including the entire E. coli lactose operon (lacIPOZYA) was inserted in one copy into the chromosome of Pseudomonas putida, Pseudomonas fluorescens and an E. coli strain with lac(-) phenotype. This was made possible by improvements of an already existing mini-Tn5 transposon...... flanked by NotI sites needed in the mini-Tn5 delivery system; (b) the generation of E. coli nonlysogenic strains expressing the pi protein thus being capable of maintaining and delivering R6K-based mini-Tn5 vectors to other E. coli strains; (c) the successful insertion of the E. coli lactose operon...... into the P. fluorescens chromosome giving P. fluorescens the ability to grow on lactose; (d) evidence from Southern blotting that contradicts the assumption that the mini-Tn5 delivery system always creates one-copy inserts. These improvements allow insertion of large DNA fragments encoding highly expressed...

Environmental Exposure of Sperm Sex-Chromosomes: A Gender Selection Technique.

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Oyeyipo, Ibukun P; van der Linde, Michelle; du Plessis, Stefan S

2017-10-01

Preconceptual sex selection is still a highly debatable process whereby X- and Y-chromosome-bearing spermatozoa are isolated prior to fertilization of the oocyte. Although various separation techniques are available, none can guarantee 100% accuracy. The aim of this study was to separate X- and Y-chromosome-bearing spermatozoa using methods based on the viability difference between the X- and Y-chromosome-bearing spermatozoa. A total of 18 experimental semen samples were used, written consent was obtained from all donors and results were analysed in a blinded fashion. Spermatozoa were exposed to different pH values (5.5, 6.5, 7.5, 8.5, and 9.5), increased temperatures (37°C, 41°C, and 45°C) and ROS level (50 μM, 750 μM, and 1,000 μM). The live and dead cell separation was done through a modified swim-up technique. Changes in the sex-chromosome ratio of samples were established by double-label fluorescent in situ hybridization (FISH) before and after processing. The results indicated successful enrichment of Xchromosome-bearing spermatozoa upon incubation in acidic media, increased temperatures, and elevated H 2 O 2 . This study demonstrated the potential role for exploring the physiological differences between X-and Y-chromosome-bearing spermatozoa in the development of preconceptual gender selection.

Chromosomal Mapping of Repetitive DNAs in the Grasshopper Abracris flavolineata Reveal Possible Ancestry of the B Chromosome and H3 Histone Spreading

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Bueno, Danilo; Palacios-Gimenez, Octavio Manuel; Cabral-de-Mello, Diogo Cavalcanti

2013-01-01

Supernumerary chromosomes (B chromosomes) occur in approximately 15% of eukaryote species. Although these chromosomes have been extensively studied, knowledge concerning their specific molecular composition is lacking in most cases. The accumulation of repetitive DNAs is one remarkable characteristic of B chromosomes, and the occurrence of distinct types of multigene families, satellite DNAs and some transposable elements have been reported. Here, we describe the organization of repetitive DNAs in the A complement and B chromosome system in the grasshopper species Abracris flavolineata using classical cytogenetic techniques and FISH analysis using probes for five multigene families, telomeric repeats and repetitive C0t-1 DNA fractions. The 18S rRNA and H3 histone multigene families are highly variable and well distributed in A. flavolineata chromosomes, which contrasts with the conservation of U snRNA genes and less variable distribution of 5S rDNA sequences. The H3 histone gene was an extensively distributed with clusters occurring in all chromosomes. Repetitive DNAs were concentrated in C-positive regions, including the pericentromeric region and small chromosomal arms, with some occurrence in C-negative regions, but abundance was low in the B chromosome. Finally, the first demonstration of the U2 snRNA gene in B chromosomes in A. flavolineata may shed light on its possible origin. These results provide new information regarding chromosomal variability for repetitive DNAs in grasshoppers and the specific molecular composition of B chromosomes. PMID:23826099

Tumour radiosensitization with the halogenated pyrimidines 5'-bromo-and 5'-iododeoxyuridine

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Epstein, A.H.; Cook, J.A.; Goffman, T. (National Cancer Inst., Bethesda, MD (United States)); Glatstein, E. (Texas Univ., Dallas, TX (United States). Southwestern Medical Center)

1993-02-01

The authors review studies of the use of iododeoxyuridine (IdUrd) and bromodeoxyuridine as radiosensitizers and attempt to correlate the clinical outcome for patients treated with radiation and IdUrd with the extent of halogenated pyrimidine cellular uptake and incorporation. (U.K.).

Meiotic chromosomal translocations in male mice induced by X-irradiation

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Savkovic, N.; Pecevski; Vuksanovic, L.; Radivojevic, D.; Alavantic, D.

1983-01-01

The dose-response curve for reciprocal translocations induced by acute exposure of spermatogonial stem cells to X-rays in treated mice and their F-1 sons was examined. Male mice were totally irradiated with doses of 1Gy;5x1Gy and 5Gy. The obtained results show that frequency of the chromosomal translocations in directly treated animals is dose dependent. The percentage of animals irradiated with 1Gy which had the chromosomal translocations was 60, while this percentage in animals irradiated with single and fractionated dose of 5Gy was 100. The frequency of chromosomal translocations varies from 1.5% to 8.0%. Multivalent configurations in F-1 males were observed after exposure to 5Gy only. The incidence of F-1 translocated males was 17.5%.

Vibrio chromosome-specific families

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Lukjancenko, Oksana; Ussery, David

2014-01-01

We have compared chromosome-specific genes in a set of 18 finished Vibrio genomes, and, in addition, also calculated the pan- and core-genomes from a data set of more than 250 draft Vibrio genome sequences. These genomes come from 9 known species and 2 unknown species. Within the finished...... chromosomes, we find a core set of 1269 encoded protein families for chromosome 1, and a core of 252 encoded protein families for chromosome 2. Many of these core proteins are also found in the draft genomes (although which chromosome they are located on is unknown.) Of the chromosome specific core protein...... families, 1169 and 153 are uniquely found in chromosomes 1 and 2, respectively. Gene ontology (GO) terms for each of the protein families were determined, and the different sets for each chromosome were compared. A total of 363 different "Molecular Function" GO categories were found for chromosome 1...

Clinical effect of increasing doses of lenalidomide in high-risk myelodysplastic syndrome and acute myeloid leukemia with chromosome 5 abnormalities

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Möllgård, Lars; Saft, Leonie; Treppendahl, Marianne Bach

2011-01-01

Patients with chromosome 5 abnormalities and high-risk myelodysplastic syndromes or acute myeloid leukemia have a poor outcome. We hypothesized that increasing doses of lenalidomide may benefit this group of patients by inhibiting the tumor clone, as assessed by fluorescence in situ hybridization...

The significance of chromosome deletions in atomic-bomb survivors

International Nuclear Information System (INIS)

Tanaka, Kimio; Shigeta, Chiharu; Oguma, Nobuo; Kamada, Nanao; Deng, Z.; Niimi, Masanobu; Aisaka, Tadaichi.

1986-01-01

In 39 A-bomb survivors 40 years after exposure at ≤ 1,000 m from ground zero, the frequency and features of chromosome deletions in peripheral lymphocytes were examined using a differential staining technique. Simultaneously, in vitro irradiation experiment with Cf-252 was made to infer chromosome aberrations occuring immediately after exposure. Californium-252 with 100 rad induced dicentric and ring chromosomes in 40 % of the cells and acentric fragments in 44 %. Among the A-bomb survivors, chromosome aberrations were observed in 651 (21 %) of the total 3,136 cells. There were 146 cells with deletions (22 % of abnormal cells; 5 % of the total cells), and 10 cells with acentric fragment (0.3 % of the total cells). The figure for deletions was far higher than that reported in the literature. A large number of deletions were seen in chromosomes no.4, no.21, and no.22, and a few deletions in chromosomes no.7 and no.20. Significance of chromosome deletions is discussed. (Namekawa, K.)

Prognostic significance of equivocal human epidermal growth factor receptor 2 results and clinical utility of alternative chromosome 17 genes in patients with invasive breast cancer: A cohort study.

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Sneige, Nour; Hess, Kenneth R; Multani, Asha S; Gong, Yun; Ibrahim, Nuhad K

2017-04-01

The 2013 testing guidelines for determining the human epidermal growth factor receptor 2 (HER2) status include new cutoff points for the HER2/chromosome enumeration probe 17 (CEP17) ratio and the average HER2 copy number per cell, and they recommend using a reflex test with alternative chromosome 17 probes (Ch17Ps) to resolve equivocal HER2 results. This study sought to determine the clinical utility of alternative Ch17Ps in equivocal cases and the effects of equivocal results and/or a change in the HER2 status on patients' outcomes. The University of Texas MD Anderson Cancer Center database of HER2 dual-probe fluorescence in situ hybridization results from 2000 to 2010 was searched for cases of invasive breast cancer with HER2/CEP17 ratios Cancer 2017;123:1115-1123. © 2016 American Cancer Society. © 2016 American Cancer Society.

Giemsa C-banding of Barley Chromosomes. IV. Chromosomal Constitution of Autotetraploid Barley

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Linde-Laursen, Ib

1984-01-01

The progeny of an autotetraploid barley plant (C1) consisted of 45 tetraploids and 33 aneuploids. Giemsa C-banding was used to identify each of the chromosomes in 20 euploid and 31 aneuploid C2--seedlings, and in 11 C3--offspring of aneuploid C2--plants. The euploid C2--seedlings all had four...... homologues of each of the chromosomes. The aneuploid C2--seedlings were fairly equally distributed on hypo-and hyperploids, and on the seven chromosome groups. This suggests that a particular chromosome is lost or gained at random in gametes and embryos. The 11 C3--seedlings comprised seven true euploids......, one seedling with 2n=28 having an extra chromosome 6 and missing one chromosome 3, and three seedlings with 2n=29. The chromosomal composition of aneuploid C3--seedlings did not reflect that of their aneuploid C2--parents with respect to missing or extra chromosomes. Two hypohexaploid C2--seedlings...

Folic acid deficiency increases chromosomal instability, chromosome 21 aneuploidy and sensitivity to radiation-induced micronuclei

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Beetstra, Sasja; Thomas, Philip; Salisbury, Carolyn; Turner, Julie; Fenech, Michael

2005-01-01

Folic acid deficiency can lead to uracil incorporation into DNA, hypomethylation of DNA, inefficient DNA repair and increase chromosome malsegregation and breakage. Because ionising radiation increases demand for efficient DNA repair and also causes chromosome breaks we hypothesised that folic acid deficiency may increase sensitivity to radiation-induced chromosome breakage. We tested this hypothesis by using the cytokinesis-block micronucleus assay in 10 day WIL2-NS cell cultures at four different folic acid concentrations (0.2, 2, 20, and 200 nM) that span the 'normal' physiological range in humans. The study showed a significant dose-dependent increase in frequency of binucleated cells with micronuclei and/or nucleoplasmic bridges with decreasing folic acid concentration (P < 0.0001, P = 0.028, respectively). These biomarkers of chromosomal instability were also increased in cells irradiated (1.5 Gy γ-rays) on day 9 relative to un-irradiated controls (P < 0.05). Folic acid deficiency and γ-irradiation were shown to have a significant interactive effect on frequency of cells containing micronuclei (two-way ANOVA, interaction P 0.0039) such that the frequency of radiation-induced micronucleated cells (i.e. after subtracting base-line frequency of un-irradiated controls) increased with decreasing folic acid concentration (P-trend < 0.0001). Aneuploidy of chromosome 21, apoptosis and necrosis were increased by folic acid deficiency but not by ionising radiation. The results of this study show that folate status has an important impact on chromosomal stability and is an important modifying factor of cellular sensitivity to radiation-induced genome damage

Mapping of rDNA on the chromosomes of Eleusine species by fluorescence in situ hybridization.

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Bisht, M S; Mukai, Y

2000-12-01

Mapping of rDNA sites on the chromosomes of four diploid and two tetraploid species of Eleusine has provided valuable information on genome relationship between the species. Presence of 18S-5.8S-26S rDNA on the largest pair of the chromosomes, location of 5S rDNA at four sites on two pairs of chromosomes and presence of 18S-5.8S-26S and 5S rDNA at same location on one pair of chromosomes have clearly differentiated E. multiflora from rest of the species of Eleusine. The two tetraploid species, E. coracana and E. africana have the same number of 18S-5.8S-26S and 5S rDNA sites and located at similar position on the chromosomes. Diploid species, E. indica, E. floccifolia and E. tristachya have the same 18S-5.8S-26S sites and location on the chromosomes which also resembled with the two pairs of 18S-5.8S-26S rDNA locations in tetraploid species, E. coracana and E. africana. The 5S rDNA sites on chromosomes of E. indica and E. floccifolia were also comparable to the 5S rDNA sites of E. africana and E. coracana. The similarity of the rDNA sites and their location on chromosomes in the three diploid and two polyploid species also supports the view that genome donors to tetraploid species may be from these diploid species.

Online performance evaluation of RAID 5 using CPU utilization

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Jin, Hai; Yang, Hua; Zhang, Jiangling

1998-09-01

Redundant arrays of independent disks (RAID) technology is the efficient way to solve the bottleneck problem between CPU processing ability and I/O subsystem. For the system point of view, the most important metric of on line performance is the utilization of CPU. This paper first employs the way to calculate the CPU utilization of system connected with RAID level 5 using statistic average method. From the simulation results of CPU utilization of system connected with RAID level 5 subsystem can we see that using multiple disks as an array to access data in parallel is the efficient way to enhance the on-line performance of disk storage system. USing high-end disk drivers to compose the disk array is the key to enhance the on-line performance of system.

Intra-chromosomal aberrations observed after high-LET radiation exposure in vivo using a state-of-the-art cytogenetic technique

International Nuclear Information System (INIS)

Mitchell, C.R.; Geard, C.R.; Brenner, D.J.; Hande, P.; Azizova, T.V.; Burak, L.E.; Khokhryakov, V.F.; Vasienko, E.K.

2003-01-01

Multicolor banding fluorescence in situ hybridization (mBAND) was used to investigate the presence of stable intra-chromosomal aberrations in chromosomes 1, 2 and 5 in a population of individuals exposed previously to low and/or high-LET radiation. Peripheral blood lymphocytes were taken from healthy Russian nuclear workers occupationally exposed to plutonium α -particles, γ -rays or both at the Mayak complex from 1949 onwards. Metaphase spreads were produced and chromosomes hybridized with mBAND probes and scored for intra-chromosomal aberrations including inversions and deletions. A large difference between the intra-chromosomal aberration frequencies for the high-plutonium (∼1.1 Gy) and the high- γ exposed (∼1.5 Gy) individuals was observed in all three chromosomes studied (chromosome 1: 1.9 ± 0.5 % (n=7) vs. 0.1 ± 0.1% (n=5); chromosome 2: 1.7 ± 0.4% (n=7) vs. 0 [0 -0.3]% (n=6); chromosome 5: 3.7 ± 0.5 % (n=11) vs. 0.1 ± 0.1 % (n=11) (high-plutonium vs. high-γ exposure)). Controls (n=5) showed very few or no intra-chromosomal aberrations. Significantly fewer aberrations were observed in chromosomes 1 and 2 compared with chromosome 5, studied previously in this cohort, suggesting that intra-chromosomal changes involving chromosomes 1 and 2 may be more lethal to the cell than those involving chromosome 5. The dramatic differences in yields of intra-chromosomal aberrations in high-plutonium exposure relative to low may provide a means of discrimination to estimate both the dose and type of previous radiation exposure in populations

Chromosome aberrations in space-exposed seeds of Allium cepa L

International Nuclear Information System (INIS)

Wang, S.

1994-01-01

Onion (Allium cepa L.) seeds c.v. Patti King were packed in sealed canisters and launched into space orbit about 296 km above earth by the space shuttle Challenger in April 1984. After more than five years exposure to space, the seeds were retrieved by the space shuttle Columbia and returned to earth in January, 1990. Somatic chromosomes at anaphase and telophase stages were analyzed and cells with normal or abnormal chromosome separations were recorded. Space-exposed and control seeds showed an average of 10.9% and 2.8% chromosome aberrations, respectively. Seeds contained in the two exterior layers of the canister had 16.5 to 18.5% chromosome aberration. The results indicated that irradiation in space would be a direct cause for chromosome aberrations in onion seeds. Analysis of seed germination rate and vigor were also determined. The average germination rate for space-exposed and control seeds were 53.3% and 19.8%, respectively. Possible reasons for the results obtained are discussed [it

Yield of chromosomal aberrations and recoil particle range in Chineses hamster fibroblasts exposed to 8.5 to 500 keV neutrons

International Nuclear Information System (INIS)

Sturelid, S.; Bergman, R.

1976-01-01

Induction of chromatid aberrations in S-phase Chinese hamster fibroblasts has been studied for irradiation by 60 Co gamma rays and neutrons of average energy 8.5, 45, 83, 200 and 500 keV. At 10 per cent aberration level the relative biological afficiency varied between 2.2 +- 0.6 (at 8.5 keV) and a maximum of 47 +- 9 (at 200 keV). The neutron generated recoils have short range in comparison to chromosomal dimensions. The strong variation with neutron energy is therefore not necessarily reflecting variations in the average linear energy transfer. Good agreement between experimental and predicted response was obtained when effects ascribed to range were considered. A critical volume within which primary lesions should occur in order to make chromosomal aberrations probable was derived. The corresponding site radius was estimated to be 1-3 μm. (author)

Localization of the endpoints of deletions in the 5' region of the Duchenne gene using a sequence isolated by chromosome jumping

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Kenwrick, S J; Smith, T J; England, S; Collins, F; Davies, K E

1988-02-25

The authors have used chromosome jumping technology to move from within a large intron sequence in the Duchenne muscular dystrophy (DMD) gene to a region adjacent to exons of the gene. The single copy jump clone, HH1, was used to characterize deletions in patients previously shown to be deleted for DNA markers in the 5' end of the gene. 12 out of 15 such patients have breakpoints which lie between HH1 and the genomic locus J-47. Thus the vast majority of the deletions in these patients have proximal breakpoints in a similar region distal to the 5'end of the gene. HH1 was mapped with respect to the X;1 translocation in a DMD female and was shown to lie at least 80 kb from the starting point of the chromosome jump, HIP25.

Targeted tandem duplication of a large chromosomal segment in Aspergillus oryzae.

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Takahashi, Tadashi; Sato, Atsushi; Ogawa, Masahiro; Hanya, Yoshiki; Oguma, Tetsuya

2014-08-01

We describe here the first successful construction of a targeted tandem duplication of a large chromosomal segment in Aspergillus oryzae. The targeted tandem chromosomal duplication was achieved by using strains that had a 5'-deleted pyrG upstream of the region targeted for tandem chromosomal duplication and a 3'-deleted pyrG downstream of the target region. Consequently,strains bearing a 210-kb targeted tandem chromosomal duplication near the centromeric region of chromosome 8 and strains bearing a targeted tandem chromosomal duplication of a 700-kb region of chromosome 2 were successfully constructed. The strains bearing the tandem chromosomal duplication were efficiently obtained from the regenerated protoplast of the parental strains. However, the generation of the chromosomal duplication did not depend on the introduction of double-stranded breaks(DSBs) by I-SceI. The chromosomal duplications of these strains were stably maintained after five generations of culture under nonselective conditions. The strains bearing the tandem chromosomal duplication in the 700-kb region of chromosome 2 showed highly increased protease activity in solid-state culture, indicating that the duplication of large chromosomal segments could be a useful new breeding technology and gene analysis method.

The Y chromosome of the Atelidae family (Platyrrhini): study by chromosome microdissection.

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Gifalli-Iughetti, C; Koiffmann, C P

2009-01-01

In order to study the intergeneric variability of the Y chromosome, we describe the hybridization of the Y chromosome of Brachytelesarachnoides, obtained by microdissection, to metaphases of Atelesbelzebuthmarginatus, Lagothrixlagothricha, and Alouatta male specimens. Brachytelesarachnoides (Atelinae) has 62 chromosomes and a very small Y chromosome. Our results showed that the Brachytelesarachnoides Y chromosome probe hybridized to Lagothrixlagothricha metaphases yielding one hybridization signal on only the tiny Y chromosome, and when hybridized with Atelesbelzebuthmarginatus metaphases it yielded one hybridization signal on two thirds of the small acrocentric Y chromosome. However, no hybridization signal was observed in Alouatta metaphases (subfamily Alouattinae), a closely related genus in the Atelidae family. Furthermore, our data support a close phylogenetic relationship among Brachyteles, Ateles, and Lagothrix and their placement in the Atelinae subfamily, but exclude Alouatta from this group indicating its placement as basal to this group. Copyright 2009 S. Karger AG, Basel.

Chromosome painting in the manatee supports Afrotheria and Paenungulata

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Zori Roberto T

2007-01-01

Full Text Available Abstract Background Sirenia (manatees, dugongs and Stellar's sea cow have no evolutionary relationship with other marine mammals, despite similarities in adaptations and body shape. Recent phylogenomic results place Sirenia in Afrotheria and with elephants and rock hyraxes in Paenungulata. Sirenia and Hyracoidea are the two afrotherian orders as yet unstudied by comparative molecular cytogenetics. Here we report on the chromosome painting of the Florida manatee. Results The human autosomal and X chromosome paints delimited a total of 44 homologous segments in the manatee genome. The synteny of nine of the 22 human autosomal chromosomes (4, 5, 6, 9, 11, 14, 17, 18 and 20 and the X chromosome were found intact in the manatee. The syntenies of other human chromosomes were disrupted in the manatee genome into two to five segments. The hybridization pattern revealed that 20 (15 unique associations of human chromosome segments are found in the manatee genome: 1/15, 1/19, 2/3 (twice, 3/7 (twice, 3/13, 3/21, 5/21, 7/16, 8/22, 10/12 (twice, 11/20, 12/22 (three times, 14/15, 16/19 and 18/19. Conclusion There are five derived chromosome traits that strongly link elephants with manatees in Tethytheria and give implicit support to Paenungulata: the associations 2/3, 3/13, 8/22, 18/19 and the loss of the ancestral eutherian 4/8 association. It would be useful to test these conclusions with chromosome painting in hyraxes. The manatee chromosome painting data confirm that the associations 1/19 and 5/21 phylogenetically link afrotherian species and show that Afrotheria is a natural clade. The association 10/12/22 is also ubiquitous in Afrotheria (clade I, present in Laurasiatheria (clade IV, only partially present in Xenarthra (10/12, clade II and absent in Euarchontoglires (clade III. If Afrotheria is basal to eutherians, this association could be part of the ancestral eutherian karyotype. If afrotherians are not at the root of the eutherian tree, then the 10

Rab5 GTPase controls chromosome alignment through Lamin disassembly and relocation of the NuMA-like protein Mud to the poles during mitosis

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Capalbo, Luisa; D'Avino, Pier Paolo; Archambault, Vincent; Glover, David M.

2011-01-01

The small GTPase Rab5 is a conserved regulator of membrane trafficking; it regulates the formation of early endosomes, their transport along microtubules, and the fusion to the target organelles. Although several members of the endocytic pathway were recently implicated in spindle organization, it is unclear whether Rab5 has any role during mitosis. Here, we describe that Rab5 is required for proper chromosome alignment during Drosophila mitoses. We also found that Rab5 associated in vivo with nuclear Lamin and mushroom body defect (Mud), the Drosophila counterpart of nuclear mitotic apparatus protein (NuMA). Consistent with this finding, Rab5 was required for the disassembly of the nuclear envelope at mitotic entry and the accumulation of Mud at the spindle poles. Furthermore, Mud depletion caused chromosome misalignment defects that resembled the defects of Rab5 RNAi cells, and double-knockdown experiments indicated that the two proteins function in a linear pathway. Our results indicate a role for Rab5 in mitosis and reinforce the emerging view of the contributions made by cell membrane dynamics to spindle function. PMID:21987826

Micromechanics of human mitotic chromosomes

International Nuclear Information System (INIS)

Sun, Mingxuan; Kawamura, Ryo; Marko, John F

2011-01-01

Eukaryote cells dramatically reorganize their long chromosomal DNAs to facilitate their physical segregation during mitosis. The internal organization of folded mitotic chromosomes remains a basic mystery of cell biology; its understanding would likely shed light on how chromosomes are separated from one another as well as into chromosome structure between cell divisions. We report biophysical experiments on single mitotic chromosomes from human cells, where we combine micromanipulation, nano-Newton-scale force measurement and biochemical treatments to study chromosome connectivity and topology. Results are in accord with previous experiments on amphibian chromosomes and support the 'chromatin network' model of mitotic chromosome structure. Prospects for studies of chromosome-organizing proteins using siRNA expression knockdowns, as well as for differential studies of chromosomes with and without mutations associated with genetic diseases, are also discussed

A large-scale chromosome-specific SNP discovery guideline.

Science.gov (United States)

Akpinar, Bala Ani; Lucas, Stuart; Budak, Hikmet

2017-01-01

Single-nucleotide polymorphisms (SNPs) are the most prevalent type of variation in genomes that are increasingly being used as molecular markers in diversity analyses, mapping and cloning of genes, and germplasm characterization. However, only a few studies reported large-scale SNP discovery in Aegilops tauschii, restricting their potential use as markers for the low-polymorphic D genome. Here, we report 68,592 SNPs found on the gene-related sequences of the 5D chromosome of Ae. tauschii genotype MvGB589 using genomic and transcriptomic sequences from seven Ae. tauschii accessions, including AL8/78, the only genotype for which a draft genome sequence is available at present. We also suggest a workflow to compare SNP positions in homologous regions on the 5D chromosome of Triticum aestivum, bread wheat, to mark single nucleotide variations between these closely related species. Overall, the identified SNPs define a density of 4.49 SNPs per kilobyte, among the highest reported for the genic regions of Ae. tauschii so far. To our knowledge, this study also presents the first chromosome-specific SNP catalog in Ae. tauschii that should facilitate the association of these SNPs with morphological traits on chromosome 5D to be ultimately targeted for wheat improvement.

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

Aplastic Anemia in Two Patients with Sex Chromosome Aneuploidies.

Science.gov (United States)

Rush, Eric T; Schaefer, G Bradley; Sanger, Warren G; Coccia, Peter F

2015-01-01

Sex chromosome aneuploidies range in incidence from rather common to exceedingly rare and have a variable phenotype. We report 2 patients with sex chromosome aneuploidies who developed severe aplastic anemia requiring treatment. The first patient had tetrasomy X (48,XXXX) and presented at 9 years of age, and the second patient had trisomy X (47,XXX) and presented at 5 years of age. Although aplastic anemia has been associated with other chromosomal abnormalities, sex chromosome abnormalities have not been traditionally considered a risk factor for this condition. A review of the literature reveals that at least one other patient with a sex chromosome aneuploidy (45,X) has suffered from aplastic anemia and that other autosomal chromosomal anomalies have been described. Despite the uncommon nature of each condition, it is possible that the apparent association is coincidental. A better understanding of the genetic causes of aplastic anemia remains important. © 2015 S. Karger AG, Basel.

Cloning of Bovine herpesvirus type 1 and type 5 as infectious bacterial artifical chromosomes

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Ackermann Mathias

2009-10-01

Full Text Available Abstract Background Bovine herpesviruses type 1 (BoHV1 and type 5 (BoHV5 are two closely related pathogens of cattle. The identity of the two viruses on the amino acid level averages 82%. Despite their high antigenetic similarities the two pathogens induce distinctive clinical signs. BoHV1 causes respiratory and genital tract infections while BoHV5 leads to severe encephalitis in calves. Findings The viral genomes of BoHV1 and BoHV5 were cloned as infectious bacterial artificial chromosomes (BACs. First, recombinant viruses carrying the genetic elements for propagation in bacteria were generated. Second, DNA from these recombinant viruses were transferred into prokaryotic cells. Third, DNA from these bacteria were transferred into eukaryotic cells. Progeny viruses from BAC transfections showed similar kinetics as their corresponding wild types. Conclusion The two viral genomes of BoHV1 and BoHV5 cloned as BACs are accessible to the tools of bacterial genetics. The ability to easily manipulate the viral genomes on a molecular level in future experiments will lead to a better understanding of the difference in pathogenesis induced by these two closely related bovine herpesviruses.

Interphase Chromosome Profiling: A Method for Conventional Banded Chromosome Analysis Using Interphase Nuclei.

Science.gov (United States)

Babu, Ramesh; Van Dyke, Daniel L; Dev, Vaithilingam G; Koduru, Prasad; Rao, Nagesh; Mitter, Navnit S; Liu, Mingya; Fuentes, Ernesto; Fuentes, Sarah; Papa, Stephen

2018-02-01

- Chromosome analysis on bone marrow or peripheral blood samples fails in a small proportion of attempts. A method that is more reliable, with similar or better resolution, would be a welcome addition to the armamentarium of the cytogenetics laboratory. - To develop a method similar to banded metaphase chromosome analysis that relies only on interphase nuclei. - To label multiple targets in an equidistant fashion along the entire length of each chromosome, including landmark subtelomere and centromere regions. Each label so generated by using cloned bacterial artificial chromosome probes is molecularly distinct with unique spectral characteristics, so the number and position of the labels can be tracked to identify chromosome abnormalities. - Interphase chromosome profiling (ICP) demonstrated results similar to conventional chromosome analysis and fluorescence in situ hybridization in 55 previously studied cases and obtained useful ICP chromosome analysis results on another 29 cases in which conventional methods failed. - ICP is a new and powerful method to karyotype peripheral blood and bone marrow aspirate preparations without reliance on metaphase chromosome preparations. It will be of particular value for cases with a failed conventional analysis or when a fast turnaround time is required.

Chromosome break points of T-lymphocytes from atomic bomb survivors

International Nuclear Information System (INIS)

Tanaka, Kimio; Kamada, Nanao; Kuramoto, Atsushi; Ohkita, Takeshi

1980-01-01

Chromosome break points of T-lymphocytes were investigated for 9 atomic bomb survivors estimated to be irradiated with 100 - 630 red. Chromosome aberration was found in 199 cells out of 678 cells investigated, with non-random distribution. The types of the chromosome aberration were, transfer: 56%, deficit: 38%, additional abnormality 3%, and reverse: 2%. High and low incidence of chromosome aberrations were observed at the chromosome numbers of 22, 21, and 13, and 11, 12, and 4, respectively. The aberration numbers per arm were high in 22q, 21q, and 18p and low in 11q, 5p, and 12q. For the distribution of aberration number within a chromosome, 50.7% was observed at the terminal portion and 73% was at the pale band appeared by Q-partial-stain method, suggesting the non-random distribution. The incidence of aberration number in 22q was statistically significant (P 1 chromosome in chronic myelocytic leukemia. The non-random distribution of chromosome break points seemed to reflect the selection effect since irradiation. (Nakanishi, T.)

Chromosomal divergence and evolutionary inferences in Rhodniini based on the chromosomal location of ribosomal genes

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Sebastian Pita

2013-05-01

Full Text Available In this study, we used fluorescence in situ hybridisation to determine the chromosomal location of 45S rDNA clusters in 10 species of the tribe Rhodniini (Hemiptera: Reduviidae: Triatominae. The results showed striking inter and intraspecific variability, with the location of the rDNA clusters restricted to sex chromosomes with two patterns: either on one (X chromosome or both sex chromosomes (X and Y chromosomes. This variation occurs within a genus that has an unchanging diploid chromosome number (2n = 22, including 20 autosomes and 2 sex chromosomes and a similar chromosome size and genomic DNA content, reflecting a genome dynamic not revealed by these chromosome traits. The rDNA variation in closely related species and the intraspecific polymorphism in Rhodnius ecuadoriensis suggested that the chromosomal position of rDNA clusters might be a useful marker to identify recently diverged species or populations. We discuss the ancestral position of ribosomal genes in the tribe Rhodniini and the possible mechanisms involved in the variation of the rDNA clusters, including the loss of rDNA loci on the Y chromosome, transposition and ectopic pairing. The last two processes involve chromosomal exchanges between both sex chromosomes, in contrast to the widely accepted idea that the achiasmatic sex chromosomes of Heteroptera do not interchange sequences.

DNA fingerprinting tags novel altered chromosomal regions and identifies the involvement of SOX5 in the progression of prostate cancer.

Science.gov (United States)

Ma, Stephanie; Chan, Yuen Piu; Woolcock, Bruce; Hu, Liang; Wong, Kai Yau; Ling, Ming Tat; Bainbridge, Terry; Webber, Douglas; Chan, Tim Hon Man; Guan, Xin-Yuan; Lam, Wan; Vielkind, Juergen; Chan, Kwok Wah

2009-05-15

Identification of genomic alterations associated with the progression of prostate cancer may facilitate the better understanding of the development of this highly variable disease. Matched normal, premalignant high-grade prostatic intraepithelial neoplasia and invasive prostate carcinoma cells were procured by laser capture microdissection (LCM) from human radical prostatectomy specimens. From these cells, comparative DNA fingerprints were generated by a modified PCR-based technique called scanning of microdissected archival lesion (SMAL)-PCR. Recurrent polymorphic fingerprint fragments were used in tagging altered chromosomal regions. Altered regions were found at cytobands 1p31.3, 1q44, 2p23.1, 3p26.3, 3q22.3, 4q22.3, 4q35.2, 5q23.2, 8q22.3, 8q24.13, 9q21.3, 9q22.32, 10q11.21, 11p13, 12p12.1, 13q12.1, 16q12.2 and 18q21.31. Candidate genes in the surrounding area that may possibly harbor mutations that change normal prostatic cells to progress into their tumor stages were proposed. Of these fragments, a 420 bp alteration, absent in all 26 normal samples screened, was observed in 2 tumors. This fragment was cloned, sequenced and localized to chromosome 12p12.1. Within this region, candidate gene sex determining region Y-box 5 (SOX5) was proposed. Further studies of SOX5 in cell lines, xenografts and human prostate specimens, at both the RNA and protein levels, found overexpression of the gene in tumors. This overexpression was then subsequently found by fluorescent in situ hybridization to be caused by amplification of the region. In conclusion, our results suggest LCM coupled with SMAL-PCR DNA fingerprinting is a useful method for the screening and identification of chromosomal regions and genes associated with cancer development. Further, overexpression of SOX5 is associated with prostate tumor progression and early development of distant metastasis. (c) 2008 Wiley-Liss, Inc.

Chromosomal instability in the progeny of irradiated parents

International Nuclear Information System (INIS)

Voro btsova, I.E.; Vorobyova, M.V.; Bogomazova, A.N.

1997-01-01

Genomic instability have been demonstrated in irradiated cells as the increased frequency of sporadic chromosome aberrations persisted over multiple generations of cell divisions. We found that chromosomal instability characterized as well the somatic cells of irradiated parents progeny. It means that radiation induced genomic instability can be transmitted via germ line cells. As a measure of instability the sensitivity of chromosomes to radiation was estimated. In animal experiments the irradiation of mature germ cells of male rats (dose - 4.5 Gy of X-rays) increase the frequency of chromosome aberrations induced by challenging irradiation in regenerating hepatocytes, in bone marrow cells and in fetal fibroblasts in the progeny of irradiated male rats. The chromosomal sensitivity of cultivated lymphocytes to in vitro irradiation (1.5 Gy of γ(rays 137 Cs) is increased in the children born parents undergone antitumor radiotherapy or worked as 'liquidators' of Chernobyl accident consequences before conception in comparison to the children of unexposed parents. The cytogenetic radiosensitivity of lymphocytes to irradiation in vitro is also increased in children evacuated from contaminated by radionuclides areas ('positive' control group). The increased spontaneous frequency of chromatid-type acentric was found in all group of children with irradiation history. The instability of genome of irradiated parents progeny seems could be the mechanism of these health effects. (authors)

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

Fetal chromosome analysis

DEFF Research Database (Denmark)

Philip, J; Tabor, A; Bang, J

1983-01-01

The aim of the study was to investigate the rationale of the current indications for fetal chromosome analysis. 5372 women had 5423 amniocentesis performed, this group constituting a consecutive sample at the chromosome laboratory, Rigshospitalet, Copenhagen from March 1973 to September 1980 (Group...... A + B). Pregnant women 35 years of age, women who previously had a chromosomally abnormal child, families with translocation carriers or other heritable chromosomal disease, families where the father was 50 years or more and women in families with a history of Down's syndrome (group A), were compared...... to women having amniocentesis, although considered not to have any increased risk of fetal chromosome abnormality (1390 pregnancies, group B). They were also compared with 750 consecutive pregnancies in women 25-34 years of age, in whom all heritable diseases were excluded (group C). The risk of unbalanced...

Microdissection and chromosome painting of the alien chromosome in an addition line of wheat-Thinopyrum intermedium

Science.gov (United States)

The chromosome painting is an efficient tool for chromosome research. However, plant chromosome painting is relatively underdeveloped. In this study, chromosome painting was developed and used to identify alien chromosomes in TAi-27, a wheat-Thinopyrum intermedium addition line, and chromosomes of...

Microdissection and chromosome painting of the alien chromosome in an addition line of wheat--Thinopyrum intermedium.

Science.gov (United States)

Deng, Chuanliang; Bai, Lili; Fu, Shulan; Yin, Weibo; Zhang, Yingxin; Chen, Yuhong; Wang, Richard R-C; Zhang, Xiangqi; Han, Fangpu; Hu, Zanmin

2013-01-01

In this study, chromosome painting was developed and used to identify alien chromosomes in TAi-27, a wheat--Thinopyrum intermedium addition line, and the chromosomes of the three different genomes of Th. Intermedium. The smallest alien chromosome of TAi-27 was microdissected and its DNA amplified by DOP-PCR was used as a probe to hybridize with metaphase chromosomes of TAi-27 and Th. intermedium. Results showed that hybridization signals were observed in all regions of a pair of the smallest alien chromosomes and the pericentromeric area of another pair of alien chromosomes in TAi-27, indicating that the probe from microdissected chromosome is species specific. In Th. intermedium, 14 chromosomes had wide and strong hybridization signals distributed mainly on the pericentromere area and 9 chromosomes with narrow and weak signals on the pericentromere area. The remaining chromosomes displayed a very weak or no signal. Sequential FISH/GISH on Th. intermedium chromosomes using the DNAs of microdissected chromosome, Pseudoroegneria spicata (St genome) and pDbH12 (a J(s) genome specific probe) as the probes indicated that the microdissected chromosome belonged to the St genome, three genomes (J(s) , J and St) in Th. intermedium could be distinguished, in which there is no hybridization signal on J genome that is similar to the genome of Th. bessarabicum. Our results showed that the smallest alien chromosomes may represent a truncated chromosome and the repetitive sequence distribution might be similar in different chromosomes within the St genome. However, the repetitive sequence distributions are different within the J(s) genome, within a single chromosome, and among different genomes in Th. intermedium. Our results suggested that chromosome painting could be feasible in some plants and useful in detecting chromosome variation and repetitive sequence distribution in different genomes of polyploidy plants, which is helpful for understanding the evolution of different

Microdissection and Chromosome Painting of the Alien Chromosome in an Addition Line of Wheat - Thinopyrum intermedium

Science.gov (United States)

Yin, Weibo; Zhang, Yingxin; Chen, Yuhong; Wang, Richard R.-C.; Zhang, Xiangqi; Han, Fangpu; Hu, Zanmin

2013-01-01

In this study, chromosome painting was developed and used to identify alien chromosomes in TAi-27, a wheat - Thinopyrum intermedium addition line, and the chromosomes of the three different genomes of Th. Intermedium. The smallest alien chromosome of TAi-27 was microdissected and its DNA amplified by DOP-PCR was used as a probe to hybridize with metaphase chromosomes of TAi-27 and Th . intermedium . Results showed that hybridization signals were observed in all regions of a pair of the smallest alien chromosomes and the pericentromeric area of another pair of alien chromosomes in TAi-27, indicating that the probe from microdissected chromosome is species specific. In Th . intermedium , 14 chromosomes had wide and strong hybridization signals distributed mainly on the pericentromere area and 9 chromosomes with narrow and weak signals on the pericentromere area. The remaining chromosomes displayed a very weak or no signal. Sequential FISH/GISH on Th . intermedium chromosomes using the DNAs of microdissected chromosome, Pseudoroegneria spicata (St genome) and pDbH12 (a Js genome specific probe) as the probes indicated that the microdissected chromosome belonged to the St genome, three genomes (Js, J and St) in Th . intermedium could be distinguished, in which there is no hybridization signal on J genome that is similar to the genome of Th . bessarabicum . Our results showed that the smallest alien chromosomes may represent a truncated chromosome and the repetitive sequence distribution might be similar in different chromosomes within the St genome. However, the repetitive sequence distributions are different within the Js genome, within a single chromosome, and among different genomes in Th . intermedium . Our results suggested that chromosome painting could be feasible in some plants and useful in detecting chromosome variation and repetitive sequence distribution in different genomes of polyploidy plants, which is helpful for understanding the evolution of different

Utilization during mitotic cell division of loci controlling meiotic recombination and disjunction in Drosophila melanogaster

International Nuclear Information System (INIS)

Baker, B.S.; Carpenter, A.T.C.; Ripoll, P.

1978-01-01

To inquire whether the loci identified by recombination-defective and disjunction-defective meiotic mutants in Drosophila are also utilized during mitotic cell division, the effects of 18 meiotic mutants (representing 13 loci) on mitotic chromosome stability have been examined genetically. To do this, meiotic-mutant-bearing flies heterozygous for recessive somatic cell markers were examined for the frequencies and types of spontaneous clones expressing the cell markers. In such flies, marked clones can arise via mitotic recombination, mutation, chromosome breakage, nondisjunction or chromosome loss, and clones from these different origins can be distinguished. In addition, meiotic mutants at nine loci have been examined for their effects on sensitivity to killing by uv and x rays. Mutants at six of the seven recombination-defective loci examined (mei-9, mei-41, c(3)G, mei-W68, mei-S282, mei-352, mei-218) cause mitotic chromosome instability in both sexes, whereas mutants at one locus (mei-218) do not affect mitotic chromosome stability. Thus many of the loci utilized during meiotic recombination also function in the chromosomal economy of mitotic cells

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

Designing of plant artificial chromosome (PAC) by using the Chlorella smallest chromosome as a model system.

Science.gov (United States)

Noutoshi, Y; Arai, R; Fujie, M; Yamada, T

1997-01-01

As a model for plant-type chromosomes, we have been characterizing molecular organization of the Chlorella vulgaris C-169 chromosome I. To identify chromosome structural elements including the centromeric region and replication origins, we constructed a chromosome I specific cosmid library and aligned each cosmid clones to generate contigs. So far, more than 80% of the entire chromosome I has been covered. A complete clonal physical reconstitution of chromosome I provides information on the structure and genomic organization of plant genome. We propose our strategy to construct an artificial chromosome by assembling the functional chromosome structural elements identified on Chrorella chromosome I.

The prevalence of Y chromosome microdeletions in Pakistani infertile men

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Rubina Tabassum Siddiqui

2013-01-01

Full Text Available Background: Microdeletions of the azoospermia factor locus of the long arm of Y chromosome are an etiological factor of severe oligozoospermia or azoospermia. Objective: The aim of this study was to investigate the prevalence of Y-chromosome microdeletions in AZF region and their role in infertility in Pakistani population. Materials and Methods: The type of deletions in AZF locus were detected in infertile men (n=113 and the association of Y chromosome microdeletions with male infertility was assessed by including men (50 with normal karyotype and having children. Y chromosome microdeletions were detected by multiplex PCR using 10 sequence tagged sites namely sY81, sY130, sY141, sY142, sY155, sY157, sY160, sY182, sY231, and sY202 that covered all three regions of AZF. Results: Individuals with severe oligozoospermia showed 2.86% deletion frequency in AZFc region as compared to azoospermic males (5.5%. Conclusion: The results of our study showed that deletions in Y chromosome are not playing major part in male infertility. Moreover, multiplex-PCR strategy might preferably be employed for the detection of Y chromosome microdeletions allied to male infertility.

Localization of the endpoints of deletions in the 5' region of the Duchenne gene using a sequence isolated by chromosome jumping

Energy Technology Data Exchange (ETDEWEB)

Kenwrick, S.J.; Smith, T.J.; England, S.; Collins, F.; Davies, K.E.

1988-02-25

The authors have used chromosome jumping technology to move from within a large intron sequence in the Duchenne muscular dystrophy (DMD) gene to a region adjacent to exons of the gene. The single copy jump clone, HH1, was used to characterize deletions in patients previously shown to be deleted for DNA markers in the 5' end of the gene. 12 out of 15 such patients have breakpoints which lie between HH1 and the genomic locus J-47. Thus the vast majority of the deletions in these patients have proximal breakpoints in a similar region distal to the 5'end of the gene. HH1 was mapped with respect to the X;1 translocation in a DMD female and was shown to lie at least 80 kb from the starting point of the chromosome jump, HIP25.

Demarcation of informative chromosomes in tropical sweet corn inbred lines using microsatellite DNA markers

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Pedram Kashiani

2012-01-01

Full Text Available A study of genetic variation among 10 pairs of chromosomes extracted from 13 tropical sweet corn inbred lines, using 99 microsatellite markers, revealed a wide range of genetic diversity. Allelic richness and the number of effective alleles per chromosome ranged from 2.78 to 4.33 and 1.96 to 3.47, respectively, with respective mean values of 3.62 and 2.73. According to the Shannon's information index (I and Nei's gene diversity coefficient (Nei, Chromosome 10 was the most informative chromosome (I = 1.311 and Nei = 0.703, while Chromosome 2 possessed the least (I = 0.762 and Nei = 0.456. Based on linkage disequilibrium (LD measurements for loci less than 50 cM apart on the same chromosome, all loci on Chromosomes 1, 6 and 7 were in equilibrium. Even so, there was a high proportion of genetic variation in Chromosomes 4, 5, 8, 9 and 10, thereby revealing their appropriateness for use in the genetic diversity investigations among tropical sweet corn lines. Chromosome 4, with the highest number of loci in linkage disequilibrium, was considered the best for marker-phenotype association and QTL mapping, followed by Chromosomes 5, 8, 9 and 10.

Sex-chromosome anaphase movements in crane-fly spermatocytes are coordinated: ultraviolet microbeam irradiation of one kinetochore of one sex chromosome blocks the movements of both sex chromosomes

International Nuclear Information System (INIS)

Swedak, J.A.M.; Forer, A.

1987-01-01

Sex chromosomes in crane-fly spermatocytes move polewards at anaphase after the autosomes have reached the poles. We irradiated one kinetochore of one sex chromosome using an ultraviolet microbeam. When both sex chromosomes were normally oriented, irradiation of a single kinetochore permanently blocked movement of both sex chromosomes. Irradiation of non-kinetochore chromosomal regions or of spindle fibres did not block movement, or blocked movement only temporarily. We argue that ultraviolet irradiation of one kinetochore blocks movement of both sex chromosomes because of effects on a 'signal' system. Irradiation of one kinetochore of a maloriented sex chromosome did not block motion of either sex chromosome. However, irradiation of one kinetochore of a normally oriented sex chromosome permanently blocked motion of both that sex chromosome and the maloriented sex chromosome. Thus for the signal system to allow the sex chromosomes to move to the pole each sex chromosome must have one spindle fibre to each pole. (author)

Chromosomal Conditions

Science.gov (United States)

... and more. Stony Point, NY 10980 Close X Home > Complications & Loss > Birth defects & other health conditions > Chromosomal conditions Chromosomal conditions ... Disorders See also: Genetic counseling , Your family health history Last reviewed: February, 2013 ... labor & premature birth The newborn intensive care unit (NICU) Birth defects & ...

Electochemical detection of chromosome translocation

DEFF Research Database (Denmark)

Kwasny, Dorota; Dimaki, Maria; Silahtaroglu, Asli

2014-01-01

Cytogenetics is a study of the cell structure with a main focus on chromosomes content and their structure. Chromosome abnormalities, such as translocations may cause various genetic disorders and heametological malignancies. Chromosome translocations are structural rearrangements of two...... chromosomes that results in formation of derivative chromosomes with a mixed DNA sequence. The method currently used for their detection is Fluorescent In Situ Hybridization, which requires a use of expensive, fluorescently labeled probes that target the derivative chromosomes. We present here a double...... hybridization approach developed for label-free detection of the chromosome translocations. For specific translocation detection it is necessary to determine that the two DNA sequences forming a derivative chromosome are connected, which is achieved by two subsequent hybridization steps. The electrochemical...

Identification of supernumerary ring chromosome 1 mosaicism using fluorescence in situ hybridization.

Science.gov (United States)

Chen, H; Tuck-Muller, C M; Batista, D A; Wertelecki, W

1995-03-27

We report on a 15-year-old black boy with severe mental retardation, multiple congenital anomalies, and a supernumerary ring chromosome mosaicism. Fluorescence in situ hybridization with a chromosome 1 painting probe (pBS1) identified the ring as derived from chromosome 1. The karyotype was 46,XY/47,XY,+r(1)(p13q23). A review showed 8 reports of ring chromosome 1. In 5 cases, the patients had a non-supernumerary ring chromosome 1 resulting in partial monosomies of the short and/or long arm of chromosome 1. In 3 cases, the presence of a supernumerary ring resulted in partial trisomy of different segments of chromosome 1. In one of these cases the supernumerary ring was composed primarily of the centromere and the heterochromatic region of chromosome 1, resulting in normal phenotype. Our patient represents the third report of a supernumerary ring chromosome 1 resulting in abnormal phenotype.

Tyramide-FISH mapping of single genes for development of an integrated recombination and cytogenetic map of chromosome 5 of Allium cepa

Science.gov (United States)

Chromosome 5 of onion carries major quantitative trait loci (QTL) of interest to breeders that control dry-matter content, pungency and storability of bulbs, amounts and types of epicuticular waxes, and resistances to abiotic factors. SNPs, SSRs and RFLPs in expressed regions of the onion genome hav...

Additional chromosome abnormalities in chronic myeloid leukemia

Directory of Open Access Journals (Sweden)

Hui-Hua Hsiao

2011-02-01

Full Text Available The Philadelphia (Ph chromosome and/or Breakpoint cluster region-Abelson leukemia virus oncogene transcript are unique markers for chronic myeloid leukemia (CML. However, CML demonstrates heterogeneous presentations and outcomes. We analyzed the cytogenetic and molecular results of CML patients to evaluate their correlation with clinical presentations and outcome. A total of 84 newly diagnosed CML patients were enrolled in the study. Patients were treated according to disease status. Bone marrow samples were obtained to perform cytogenetic and molecular studies. Clinical presentations, treatment courses, and survival were reviewed retrospectively. Among 84 patients, 72 had chronic phase and 12 had accelerated phase CML. Cytogenetic study showed 69 (82.1% with the classic Ph chromosome, 6 (7.2% with a variant Ph chromosome, and 9 (10.7% with additional chromosome abnormalities. Fifty-four (64.3% cases harbored b3a2 transcripts, 29 (34.5% had b2a2 transcript, and 1 had e19a2 transcript. There was no difference in clinical presentations between different cytogenetic and molecular groups; however, additional chromosome abnormalities were significantly associated with the accelerated phase. Imatinib therapy was an effective treatment, as measured by cytogenetic response, when administered as first- and second-line therapy in chronic phase patients. Survival analysis showed that old age, additional chromosome abnormalities, high Sokal score, and no cytogenetic response in second-line therapy had a significant poor impact (p<0.05. In conclusion, we presented the cytogenetic and molecular pattern of CML patients and demonstrated that the additional chromosome abnormality was associated with poor outcome.

Microdissection and chromosome painting of the alien chromosome in an addition line of wheat--Thinopyrum intermedium.

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Chuanliang Deng

Full Text Available In this study, chromosome painting was developed and used to identify alien chromosomes in TAi-27, a wheat--Thinopyrum intermedium addition line, and the chromosomes of the three different genomes of Th. Intermedium. The smallest alien chromosome of TAi-27 was microdissected and its DNA amplified by DOP-PCR was used as a probe to hybridize with metaphase chromosomes of TAi-27 and Th. intermedium. Results showed that hybridization signals were observed in all regions of a pair of the smallest alien chromosomes and the pericentromeric area of another pair of alien chromosomes in TAi-27, indicating that the probe from microdissected chromosome is species specific. In Th. intermedium, 14 chromosomes had wide and strong hybridization signals distributed mainly on the pericentromere area and 9 chromosomes with narrow and weak signals on the pericentromere area. The remaining chromosomes displayed a very weak or no signal. Sequential FISH/GISH on Th. intermedium chromosomes using the DNAs of microdissected chromosome, Pseudoroegneria spicata (St genome and pDbH12 (a J(s genome specific probe as the probes indicated that the microdissected chromosome belonged to the St genome, three genomes (J(s , J and St in Th. intermedium could be distinguished, in which there is no hybridization signal on J genome that is similar to the genome of Th. bessarabicum. Our results showed that the smallest alien chromosomes may represent a truncated chromosome and the repetitive sequence distribution might be similar in different chromosomes within the St genome. However, the repetitive sequence distributions are different within the J(s genome, within a single chromosome, and among different genomes in Th. intermedium. Our results suggested that chromosome painting could be feasible in some plants and useful in detecting chromosome variation and repetitive sequence distribution in different genomes of polyploidy plants, which is helpful for understanding the evolution of

Three loci on mouse chromosome 5 and 10 modulate sex determination in XX Ods/+ mice.

Science.gov (United States)

Poirier, Christophe; Moran, Jennifer L; Kovanci, Ertug; Petit, Deborah C; Beier, David R; Bishop, Colin E

2007-07-01

In mouse, XY embryos are committed to the male sex determination pathway after the transient expression of the Y-linked Sry gene in the Sertoli cell lineage between 10.5 and 12.5 dpc. In the C57BL/6J strain, male sex determination program can be modulated by some autosomal genes. The C57BL/6J alleles at these autosomal loci can antagonize male sex determination in combination with specific Sry alleles. In this report, the authors have identified an effect of these C57BL/6J specific alleles in combination with a mutated Sox9 allele, Sox9(Ods). Authors report the mapping of three of these genetic loci on mouse chromosome 5 and 10 in a backcross of the Ods mutation to the C57BL/6J background. Our study confirms the importance of the strain C57BL/6J for the investigation of the genetic mechanisms that control sex determination.

Population genetic study of 34 X-Chromosome markers in 5 main ethnic groups of China.

Science.gov (United States)

Zhang, Suhua; Bian, Yingnan; Li, Li; Sun, Kuan; Wang, Zheng; Zhao, Qi; Zha, Lagabaiyila; Cai, Jifeng; Gao, Yuzhen; Ji, Chaoneng; Li, Chengtao

2015-12-04

As a multi-ethnic country, China has some indigenous population groups which vary in culture and social customs, perhaps as a result of geographic isolation and different traditions. However, upon close interactions and intermarriage, admixture of different gene pools among these ethnic groups may occur. In order to gain more insight on the genetic background of X-Chromosome from these ethnic groups, a set of X-markers (18 X-STRs and 16 X-Indels) was genotyped in 5 main ethnic groups of China (HAN, HUI, Uygur, Mongolian, Tibetan). Twenty-three private alleles were detected in HAN, Uygur, Tibetan and Mongolian. Significant differences (p population differentiation of HUI and Uygur. However, the HAN, Tibetan and Mongolian ethnic groups were closely clustered. Eighteen X-Indels exhibited in general congruent phylogenetic signal and similar cluster among the 5 ethnic groups compared with 16 X-STRs. Aforementioned results proved the genetic polymorphism and potential of the 34 X-markers in the 5 ethnic groups.

Pure chromosome-specific PCR libraries from single sorted chromosomes

NARCIS (Netherlands)

VanDevanter, D. R.; Choongkittaworn, N. M.; Dyer, K. A.; Aten, J. A.; Otto, P.; Behler, C.; Bryant, E. M.; Rabinovitch, P. S.

1994-01-01

Chromosome-specific DNA libraries can be very useful in molecular and cytogenetic genome mapping studies. We have developed a rapid and simple method for the generation of chromosome-specific DNA sequences that relies on polymerase chain reaction (PCR) amplification of a single flow-sorted

Small chromosomes among Danish Candida glabrata isolates originated through different mechanisms

DEFF Research Database (Denmark)

Ahmad, Khadija Mohamed; Ishchuk, Olena P.; Hellborg, Linda

2013-01-01

chromosomes, which were smaller than 0.5 Mb. Regarding the year, patient and hospital, these C. glabrata strains had independent origin and the analyzed small chromosomes were structurally not related to each other (i.e. they contained different sets of genes). We suggest that at least two mechanisms could...... exhibited mitotic instability, while the second type, which contained the corresponding genes in only one copy in the genome, was mitotically stable. Apparently, in patients C. glabrata chromosomes are frequently reshuffled resulting in new genetic configurations, including appearance of small chromosomes...

[Chromomeric organization of interphase chromosomes in Drosophila melanogaster].

Science.gov (United States)

Zhuimulev, I F; Beliaeva, E S; Zykova, T Iu; Semeshin, V F; Demakov, S A; Demakova, O V; Goncharov, F P; Khoroshko, V A; Boldyreva, L V; Kokoza, E B; Pokholkiova, G V

2013-01-01

As a result of treatment of bioinformatic data on the genome localization of structural proteins, histone modifications, DNase-hypersensitive regions, replication origins (taken from modENCODE) and their cytological localization to polytene chromosome structures, it is shown here that two types of interphase chromosomes -polytene chromosomes from salivary glands and from mitotically dividing cells cultures - demonstrate identical pictures of interband/band, i. e. the same localization and length on physical map and the same sets of proteins. In the interbands of both chromosome types we find the proteins that control initiation of transcription (RNA-polymerase II, transcription factors), replication (ORC2) as well as proteins modifying nucleosome structure (WDS, NURF) and proteins of insulators (BEAF). The nucleosome density and H1 histone concentration in the interbands are depleted; localization of DNase-hypersensitive regions corresponds strictly to the interbands. So, we conclude that both polytene and cell line interphase chromosomes are arranged according to general principle and polytene chromosomes represent precise model of interphase chromosomes. The interbands play a critical role in the initiation of transcription and replication. The interbands of interphase chromosomes are the sites of 5' parts of genes, while the 3' gene ends are located in the adjacent bands. The constancy of interbands decondensation results in the conclusion that the "interbands" genes are constantly active, i. e. they contain "house-keeping" genes. The large late replicating bands contain genes that do not have direct contact to the adjoining interbands are usually polygenic and contain tissue-specific genes.

The X chromosome in space.

Science.gov (United States)

Jégu, Teddy; Aeby, Eric; Lee, Jeannie T

2017-06-01

Extensive 3D folding is required to package a genome into the tiny nuclear space, and this packaging must be compatible with proper gene expression. Thus, in the well-hierarchized nucleus, chromosomes occupy discrete territories and adopt specific 3D organizational structures that facilitate interactions between regulatory elements for gene expression. The mammalian X chromosome exemplifies this structure-function relationship. Recent studies have shown that, upon X-chromosome inactivation, active and inactive X chromosomes localize to different subnuclear positions and adopt distinct chromosomal architectures that reflect their activity states. Here, we review the roles of long non-coding RNAs, chromosomal organizational structures and the subnuclear localization of chromosomes as they relate to X-linked gene expression.

Chromosomal Abnormalities Associated with Neural Tube Defects (I: Full Aneuploidy

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Chih-Ping Chen

2007-12-01

Full Text Available Fetuses with neural tube defects (NTDs carry a risk of chromosomal abnormalities. The risk varies with maternal age, gestational age at diagnosis, association with other structural abnormalities, and family history of chromosome aberrations. This article provides an overview of chromosomal abnormalities associated with NTDs in embryos, fetuses, and newborn patients, and a comprehensive review of numerical chromosomal abnormalities associated with NTDs, such as trisomy 18, trisomy 13, triploidy, trisomy 9, trisomy 2, trisomy 21, trisomy 7, trisomy 8, trisomy 14, trisomy 15, trisomy 16, trisomy 5 mosaicism, trisomy 11 mosaicism, trisomy 20 mosaicism, monosomy X, and tetraploidy. NTDs may be associated with aneuploidy. Perinatal identification of NTDs should alert one to the possibility of chromosomal abnormalities and prompt a thorough cytogenetic investigation and genetic counseling.

Mutation and DNA replication in Escherichia coli treated with low concentrations of N-methyl-N'-nitro-N-nitrosoguanidine

International Nuclear Information System (INIS)

Jimenez-Sanchez, A.; Cerda-Olmedo, E.

1975-01-01

N-Methyl-N'-nitro-N-nitrosoguanidine (nitrosoguanidine) causes an unexpectedly high frequency of closely linked double mutants because of its specificity for chromosome regions in replication. Low nitrosoguanidine concentrations (I μg/ml) in liquid cultures allow replication at the normal rate and are mutagenic. It was expected that mutations would be spread over the chromosome as it replicated, but a high frequency of closely linked double mutants was found. If a thymine auxotroph is grown in the presence of 5-bromodeoxyuridine (BUdR) and nitrosoguanidine and then exposed to 313-nm radiation (which destroys BUdR-substituted DNA), the mutation frequency is much higher among survivors than among non-irradiated cells. It is concluded that nitrosoguanidine inhibits DNA replication in a small fraction of the population and that mutations are induced in that same fraction. Nitrosoguanidine treatment leads to a high frequency of closely linked double mutants under all known conditions

Chromosome mapping of repetitive sequences in four Serrasalmidae species (Characiformes

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Leila Braga Ribeiro

2014-01-01

Full Text Available The Serrasalmidae family is composed of a number of commercially interesting species, mainly in the Amazon region where most of these fishes occur. In the present study, we investigated the genomic organization of the 18S and 5S rDNA and telomeric sequences in mitotic chromosomes of four species from the basal clade of the Serrasalmidae family: Colossoma macropomum, Mylossoma aureum, M. duriventre, and Piaractus mesopotamicus, in order to understand the chromosomal evolution in the family. All the species studied had diploid numbers 2n = 54 and exclusively biarmed chromosomes, but variations of the karyotypic formulas were observed. C-banding resulted in similar patterns among the analyzed species, with heterochromatic blocks mainly present in centromeric regions. The 18S rDNA mapping of C. macropomum and P. mesopotamicus revealed multiple sites of this gene; 5S rDNA sites were detected in two chromosome pairs in all species, although not all of them were homeologs. Hybridization with a telomeric probe revealed signals in the terminal portions of chromosomes in all the species and an interstitial signal was observed in one pair of C. macropomum.

New Y chromosomes and early stages of sex chromosome ...

Indian Academy of Sciences (India)

2010-09-06

Sep 6, 2010 ... chromosomes are evolutionary consequences of that func- tion. Given sufficient ... (for a review, see Charlesworth et al. 2005). ... In the present paper, I review sex deter- mination .... part had apparently been exchanged against the homologous ... age group III-Y chromosomes were successful while in well-.

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

Isodicentric chromosome 21: a novel aberration in acute myeloid leukemia.

Science.gov (United States)

Sankar, M; Tanaka, K; Arif, M; Shintani, T; Kumaravel, T S; Kyo, T; Dohy, H; Kamada, N

1998-11-01

We present here a 78-year-old female patient with acute myeloid leukemia (AML), French-American-British classification M2, exhibiting isodicentric chromosome 21, idic(21)(q22), at the time of diagnosis. The patient had three idic(21)(q22), besides the del(5)(q13q32), add(21)(q22), dic(21;22) (q22;q13), and +22. Fluorescence in situ hybridization studies with whole-chromosome painting and centromere-specific probes for chromosome 21 verified the diagnosis of idic(21)(q22). There were no distinct clinicohematological characteristics of AML with isodicentric 21. The patient was treated with remission-induction therapy followed by consolidation therapy. Two years later, the patient showed the disappearance of isodicentric 21 but retained del(5)(q13q32) and gained other chromosomal abnormalities, +add(17)(p11) and -16. To our knowledge, this is the first report of AML with acquired idic(21)(q22).

The influence of inhibitors on dimer removal and repair of single-strand breaks in normal and bromodeoxyuridine substituted DNA of HeLa cells

International Nuclear Information System (INIS)

Cornelis, J.J.

1978-01-01

The elimination of cyclobutane pyrimidine dimers from the nuclear DNA of ultraviolet irradiated HeLa cells has been examined by means of chromatography and immunoautoradiography. The extent and duration of the process was similar when dimers were assayed by both methods, proving that the antisera recognized pyrimidine dimers. The rate of dimer excision did not differ through the cell cycle with the exception of mitosis during which no dimers were removed. Dimer excision is a relatively fast process which is terminated within a few hours, but it leaves many dimers in the DNA. Excision is depressed by inhibitors of semiconservative DNA synthesis that affect the DNA precursor pool or DNA polymerases. Cells whose DNA is partly substituted with bromodeoxyuridine instead of thymidine, repair single-strand breaks and remove dimers at the same rate but to different extents. On the other hand, inhibitors limit repair of breaks and removal of dimers to the same degree suggesting that the repair of the two types of lesion is coordinated. (Auth.)

Localization to Chromosomes of Structural Genes for the Major Protease Inhibitors of Barley Grains

DEFF Research Database (Denmark)

Hejgaard, Jørn; Bjørn, S.E.; Nielsen, Gunnar Gissel

1984-01-01

Wheat-barley chromosome addition lines were compared by isoelectric focusing of protein extracts to identify chromosomes carrying loci for the major immunochemically distinct protease inhibitors of barley grains. Structural genes for the following inhibitors were localized: an inhibitor of both...... endogenous α-amylase 2 and subtilisin (ASI) on chromosome 2, two chymotrypsin/subtilisin inhibitors (CI-1 and CI-2) on chromosome 5 (long arm) and the major trypsin inhibitor (TI-1) on chromosome 3....

A Fine Physical Map of the Rice Chromosome 4

Science.gov (United States)

Zhao, Qiang; Zhang, Yu; Cheng, Zhukuan; Chen, Mingsheng; Wang, Shengyue; Feng, Qi; Huang, Yucheng; Li, Ying; Tang, Yesheng; Zhou, Bo; Chen, Zhehua; Yu, Shuliang; Zhu, Jingjie; Hu, Xin; Mu, Jie; Ying, Kai; Hao, Pei; Zhang, Lei; Lu, Yiqi; Zhang, Lei S.; Liu, Yilei; Yu, Zhen; Fan, Danlin; Weng, Qijun; Chen, Ling; Lu, Tingting; Liu, Xiaohui; Jia, Peixin; Sun, Tongguo; Wu, Yongrui; Zhang, Yujun; Lu, Ying; Li, Can; Wang, Rong; Lei, Haiyan; Li, Tao; Hu, Hao; Wu, Mei; Zhang, Runquan; Guan, Jianping; Zhu, Jia; Fu, Gang; Gu, Minghong; Hong, Guofan; Xue, Yongbiao; Wing, Rod; Jiang, Jiming; Han, Bin

2002-01-01

As part of an international effort to completely sequence the rice genome, we have produced a fine bacterial artificial chromosome (BAC)-based physical map of the Oryza sativa japonica Nipponbare chromosome 4 through an integration of 114 sequenced BAC clones from a taxonomically related subspecies O. sativa indica Guangluai 4 and 182 RFLP and 407 expressed sequence tag (EST) markers with the fingerprinted data of the Nipponbare genome. The map consists of 11 contigs with a total length of 34.5 Mb covering 94% of the estimated chromosome size (36.8 Mb). BAC clones corresponding to telomeres, as well as to the centromere position, were determined by BAC-pachytene chromosome fluorescence in situ hybridization (FISH). This gave rise to an estimated length ratio of 5.13 for the long arm and 2.9 for the short arm (on the basis of the physical map), which indicates that the short arm is a highly condensed one. The FISH analysis and physical mapping also showed that the short arm and the pericentromeric region of the long arm are rich in heterochromatin, which occupied 45% of the chromosome, indicating that this chromosome is likely very difficult to sequence. To our knowledge, this map provides the first example of a rapid and reliable physical mapping on the basis of the integration of the data from two taxonomically related subspecies. [The following individuals and institutions kindly provided reagents, samples, or unpublished information as indicated in the paper: S. McCouch, T. Sasaki, and Monsanto.] PMID:11997348

Deciphering neo-sex and B chromosome evolution by the draft genome of Drosophila albomicans

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Zhou Qi

2012-03-01

Full Text Available Abstract Background Drosophila albomicans is a unique model organism for studying both sex chromosome and B chromosome evolution. A pair of its autosomes comprising roughly 40% of the whole genome has fused to the ancient X and Y chromosomes only about 0.12 million years ago, thereby creating the youngest and most gene-rich neo-sex system reported to date. This species also possesses recently derived B chromosomes that show non-Mendelian inheritance and significantly influence fertility. Methods We sequenced male flies with B chromosomes at 124.5-fold genome coverage using next-generation sequencing. To characterize neo-Y specific changes and B chromosome sequences, we also sequenced inbred female flies derived from the same strain but without B's at 28.5-fold. Results We assembled a female genome and placed 53% of the sequence and 85% of the annotated proteins into specific chromosomes, by comparison with the 12 Drosophila genomes. Despite its very recent origin, the non-recombining neo-Y chromosome shows various signs of degeneration, including a significant enrichment of non-functional genes compared to the neo-X, and an excess of tandem duplications relative to other chromosomes. We also characterized a B-chromosome linked scaffold that contains an actively transcribed unit and shows sequence similarity to the subcentromeric regions of both the ancient X and the neo-X chromosome. Conclusions Our results provide novel insights into the very early stages of sex chromosome evolution and B chromosome origination, and suggest an unprecedented connection between the births of these two systems in D. albomicans.

New wheat-rye 5DS-4RS·4RL and 4RS-5DS·5DL translocation lines with powdery mildew resistance.

Science.gov (United States)

Fu, Shulan; Ren, Zhenglong; Chen, Xiaoming; Yan, Benju; Tan, Feiquan; Fu, Tihua; Tang, Zongxiang

2014-11-01

Powdery mildew is one of the serious diseases of wheat (Triticum aestivum L., 2 n = 6 × = 42, genomes AABBDD). Rye (Secale cereale L., 2 n = 2 × = 14, genome RR) offers a rich reservoir of powdery mildew resistant genes for wheat breeding program. However, extensive use of these resistant genes may render them susceptible to new pathogen races because of co-evolution of host and pathogen. Therefore, the continuous exploration of new powdery mildew resistant genes is important to wheat breeding program. In the present study, we identified several wheat-rye addition lines from the progeny of T. aestivum L. Mianyang11 × S. cereale L. Kustro, i.e., monosomic addition lines of the rye chromosomes 4R and 6R; a disomic addition line of 6R; and monotelosomic or ditelosomic addition lines of the long arms of rye chromosomes 4R (4 RL) and 6R (6 RL). All these lines displayed immunity to powdery mildew. Thus, we concluded that both the 4 RL and 6 RL arms of Kustro contain powdery mildew resistant genes. It is the first time to discover that 4 RL arm carries powdery mildew resistant gene. Additionally, wheat lines containing new wheat-rye translocation chromosomes were also obtained: these lines retained a short arm of wheat chromosome 5D (5 DS) on which rye chromosome 4R was fused through the short arm 4 RS (designated 5 DS-4 RS · 4 RL; 4 RL stands for the long arm of rye chromosome 4R); or they had an extra short arm of rye chromosome 4R (4 RS) that was attached to the short arm of wheat chromosome 5D (5 DS) (designated 4 RS-5 DS · 5 DL; 5 DL stands for the long arm of wheat chromosome 5D). These two translocation chromosomes could be transmitted to next generation stably, and the wheat lines containing 5 DS-4 RS · 4 RL chromosome also displayed immunity to powdery mildew. The materials obtained in this study can be used for wheat powdery mildew resistant breeding program.

Chromosome painting in plants.

NARCIS (Netherlands)

Schubert, I.; Fransz, P.F.; Fuchs, J.; Jong, de J.H.

2001-01-01

The current 'state-of-art' as to chromosome painting in plants is reviewed. We define different situations described as painting so far: i) Genomic in situ hybridisation (GISH) with total genomic DNA to distinguish alien chromosomes on the basis of divergent dispersed repeats, ii) 'Chromosomal in

Chromosome break points in T-lymphocytes from atomic bomb survivors

International Nuclear Information System (INIS)

Tanaka, Kimio; Kamada, Nanao; Ohkita, Takeshi; Kuramoto, Atsushi

1982-01-01

In 22 healthy A-bomb survivors who passed more than 30 years since receiving radiation, distribution of 592 chromosome break points found in T-lymphocytes of the peripheral blood was not proportional to the length, the arm length of chromosomes, nor the length of regions, but it was non-random on the chromosomes. High distribution of chromosome break points occurred in 11 regions: 22q1, 14q3, 5q3, 21q2, 6q2, 18p1, 13q3. The regions, 22q1, 14q3, 21q2, and 6q2, contained the chromosome break points which were frequently found in leukemic chromosomes. Some of the changes in nuclear-type observed in leukemic cells of A-bomb survivors were similar to those found in leukemic cells of non-exposed leukemic patients. In abnormal chromosomes of T-lymphocytes of healthy A-bomb survivors, no cells with abnormal nuclear types such as t(4;11), t(8;21), t(9;22), and t(15;17) which are seen in various types of leukemia were not found. However, cells with chromosome aberrations, 22q-, 14q+, and 6q-, were found to be 0.99%, 0.55%, and 0.25% respectively. On the basis of these results, implication of chromosome aberrations in developing cancer was discussed. (Ueda, J.)

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 utility of flow sorting to identify chromosomes carrying a single copy transgene in wheat

Czech Academy of Sciences Publication Activity Database

Cápal, Petr; Endo, Takashi R.; Vrána, Jan; Kubaláková, Marie; Karafiátová, Miroslava; Komínková, Eva; Mora-Ramirez, I.; Weschke, W.; Doležel, Jaroslav

2016-01-01

Roč. 12, APR 25 (2016), s. 24 ISSN 1746-4811 R&D Projects: GA MŠk(CZ) LO1204; GA ČR GBP501/12/G090 Institutional support: RVO:61389030 Keywords : Transgene localization * Flow cytometric sorting * Single chromosome amplification Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.510, year: 2016

Heterogeneity of chromosome 22 breakpoint in Philadelphia-positive (Ph+) acute lymphocytic leukemia

International Nuclear Information System (INIS)

Erikson, J.; Griffin, C.A.; Ar-Rushdi, A.

1986-01-01

In chronic myelogenous leukemias (CML) with the t(9;22)(q34;q11) chromosome translocation the breakpoints on chromosome 22 occur within a 5.8-kilobase segment of DNA referred to as breakpoint cluster region (bcr). The same cytogenetically indinstinguishable translocation occurs in approximately 10% of patients with acute lymphocytic leukemias (ALL). In this study the authors have investigated the chromosome breakpoints in several cases of ALL carrying the t(9;22) translocation. In three of five cases of ALL they found that the bcr region was not involved in the chromosome rearrangement and that the 22q11 chromosome breakpoints were proximal (5') to the bcr region at band 22q11. In addition, they observed normal size bcr and c-alb transcripts in an ALL cell line carrying the t(9;22) translocation. They conclude, therefore, that if c-alb is inappropriately expressed in ALL cells without bcr rearrangements, the genetic mechanism of activation must be different from that reported for CML

Chromosome painting in biological dosimetry: Semi-automatic system to score stable chromosome aberrations

International Nuclear Information System (INIS)

Garcia-Sagredo, J.M.; Vallcorba, I.; Sanchez-Hombre, M.C.; Ferro, M.T.; San Roman Cos-Gayon, C.; Santos, A.; Malpica, N.; Ortiz, C.

1997-01-01

From the beginning of the description of the procedure of chromosome painting by fluorescence in situ hybridization (FISH), it was thought its possible application to score induced chromosomal aberrations in radiation exposition. With chromosome painting it is possible to detect changes between chromosomes that has been validated in radiation exposition. Translocation scoring by FISH, contrarily to the unstable dicentrics, mainly detect stable chromosome aberrations that do not disappear, it allows the capability of quantify delayed acute expositions or chronic cumulative expositions. The large number of cells that have to be analyzed for high accuracy, specially when dealing with low radiation doses, makes it almost imperative to use an automatic analysis system. After validate translocation scoring by FISH in our, we have evaluated the ability and sensitivity to detect chromosomal aberrations by chromosome using different paint probes used, showing that any combination of paint probes can be used to score induced chromosomal aberrations. Our group has developed a FISH analysis that is currently being adapted for translocation scoring analysis. It includes systematic error correction and internal control probes. The performance tests carried out show that 9,000 cells can be analyzed in 10 hr. using a Sparc 4/370. Although with a faster computer, a higher throughput is expected, for large population screening or very low radiation doses, this performance still has to be improved. (author)

A strategy for generation and balancing of autosome: Y chromosome translocations.

Science.gov (United States)

Joshi, Sonal S; Cheong, Han; Meller, Victoria H

2014-01-01

We describe a method for generation and maintenance of translocations that move large autosomal segments onto the Y chromosome. Using this strategy we produced ( 2;Y) translocations that relocate between 1.5 and 4.8 Mb of the 2nd chromosome.. All translocations were easily balanced over a male-specific lethal 1 (msl-1) mutant chromosome. Both halves of the translocation carry visible markers, as well as P-element ends that enable molecular confirmation. Halves of these translocations can be separated to produce offspring with duplications and with lethal second chromosome deficiencies . Such large deficiencies are otherwise tedious to generate and maintain.

Preliminary analysis of numerical chromosome abnormalities in reciprocal and Robertsonian translocation preimplantation genetic diagnosis cases with 24-chromosomal analysis with an aCGH/SNP microarray.

Science.gov (United States)

Xie, Yanxin; Xu, Yanwen; Wang, Jing; Miao, Benyu; Zeng, Yanhong; Ding, Chenhui; Gao, Jun; Zhou, Canquan

2018-01-01

The aim of this study was to determine whether an interchromosomal effect (ICE) occurred in embryos obtained from reciprocal translocation (rcp) and Robertsonian translocation (RT) carriers who were following a preimplantation genetic diagnosis (PGD) with whole chromosome screening with an aCGH and SNP microarray. We also analyzed the chromosomal numerical abnormalities in embryos with aneuploidy in parental chromosomes that were not involved with a translocation and balanced in involved parental translocation chromosomes. This retrospective study included 832 embryos obtained from rcp carriers and 382 embryos from RT carriers that were biopsied in 139 PGD cycles. The control group involved embryos obtained from age-matched patient karyotypes who were undergoing preimplantation genetic screening (PGS) with non-translocation, and 579 embryos were analyzed in the control group. A single blastomere at the cleavage stage or trophectoderm from a blastocyst was biopsied, and 24-chromosomal analysis with an aCGH/SNP microarray was conducted using the PGD/PGS protocols. Statistical analyses were implemented on the incidences of cumulative aneuploidy rates between the translocation carriers and the control group. Reliable results were obtained from 138 couples, among whom only one patient was a balanced rcp or RT translocation carrier, undergoing PGD testing in our center from January 2012 to June 2014. For day 3 embryos, the aneuploidy rates were 50.7% for rcp carriers and 49.1% for RT carriers, compared with the control group, with 44.8% at a maternal age < 36 years. When the maternal age was ≥ 36 years, the aneuploidy rates were increased to 61.1% for rcp carriers, 56.7% for RT carriers, and 60.3% for the control group. There were no significant differences. In day 5 embryos, the aneuploidy rates were 24.5% for rcp carriers and 34.9% for RT carriers, compared with the control group with 53.6% at a maternal age < 36 years. When the maternal age was ≥ 36�

Regional assignment of seven genes on chromosome 1 of man by use of man-Chinese hamster somatic cell hybrids. II. Results obtained after induction of breaks in chromosome 1 by X-irradiation.

Science.gov (United States)

Burgerhout, W G; Smit, S L; Jongsma, A P

1977-01-01

The position of genes coding for PGD, PPH1, UGPP, GuK1, PGM1, Pep-C, and FH on human chromosome 1 was investigated by analysis of karyotype and enzyme phenotypes in man-Chinese hamster somatic cell hybrids carrying aberrations involving chromosome 1. Suitable hybrid cell lines were obtained by X-irradiation of hybrid cells carrying an intact chromosome 1 and by fusion of human cells from a clonal population carrying a translocation involving chromosome 1 with Chinese hamster cells. The latter human cell population had been isolated following X-irradiation of primary Lesch-Nyhan fibroblasts. In addition, products of de novo chromosome breakage in the investigated hybrid lines were utilized. By integrating the results of these analyses with earlier findings in our laboratory, the following positions of genes are deduced: PGD and PPH1 in 1p36 leads to 1p34; PGM1 in 1p32; UGPP in 1q21 leads to 1q23; GuK1 in 1q31 leads to 1q42; Pep-C in 1q42; and FH in 1qter leads to 1q42.

Pleiotropic effect of chromosome 5A and the mvp mutation on the metabolite profile during cold acclimation and the vegetative/generative transition in wheat.

Science.gov (United States)

Juhász, Zsófia; Boldizsár, Ákos; Nagy, Tibor; Kocsy, Gábor; Marincs, Ferenc; Galiba, Gábor; Bánfalvi, Zsófia

2015-02-19

Wheat is the leading source of vegetable protein in the human diet, and metabolites are crucial for both plant development and human nutrition. The recent advances in metabolomics provided an opportunity to perform an untargeted metabolite analysis in this important crop. Wheat was characterised at the metabolite level during cold acclimation and transition from the vegetative to the generative phase. The relationship between these changes and chromosome 5A and the maintained vegetative phase (mvp) mutation was also investigated. Samples were taken from the shoots and crowns during four developmental stages: plants grown at 20/17°C, after cold treatment but still during the vegetative phase, at the double ridge and during spikelet formation. The levels of 47 compounds were identified by gas chromatography-mass spectrometry, of which 38 were annotated. The cold treatment, in general, increased the concentrations of osmolites but not in all lines and not equally in the shoots and crowns. The accumulation of proline was not associated with the vernalisation process or with frost tolerance. The mvp mutation and chromosome 5A substitutions altered the amounts of several metabolites compared to those of the Tm and CS, respectively, during each developmental stage. The Ch5A substitution resulted in more substantial changes at the metabolite level than did the Tsp5A substitution. While Ch5A mainly influenced the sugar concentrations, Tsp5A altered the level of tricarboxylic acid cycle intermediates during the vegetative/generative transition. A much higher trehalose, proline, glutamine, asparagine, and unidentified m/z 186 content was detected in crowns than in shoots that may contribute to the frost tolerance of crowns. Substantial influences of chromosome 5A and the mvp mutation on metabolism during four different developmental stages were demonstrated. The distinct and overlapping accumulation patterns of metabolites suggest the complex genetic regulation of metabolism

Chromosomal mutation by fission neutrons and X-rays in higher plants. A review on results of the joint research program utilizing Kinki University reactor

International Nuclear Information System (INIS)

Yonezawa, Yoshihiko

2010-01-01

We have studied the efficiency of fission neutrons from the nuclear reactor of Kinki University (UTR-KINKI) and X-rays to chromosomes of higher plants for over 20 years. In this review, we described the development of bio-dosimeter using hyper-sensibility of germinating onion roots for irradiation, the analysis of chromosome structure in Haplopappus gracilis (Asteraceae), with the special reference of latent centromeres and survived telomeres throughout chromosomal evolution, the experimental studies on the induction of chromosomal rearrangement in Zebrina pendula (Commelinaceae), the behavior of chromosome fragments with non-localized centromeres in Carex and Eleocharis (Cyperaceae), and the possibility as a bio-dosimeter of pollen mother cells of Tradescantia paludosa (Commelinaceae) for the detection of low-dose radiation. (author)

Drug-induced premature chromosome condensation (PCC) protocols: cytogenetic approaches in mitotic chromosome and interphase chromatin.

Science.gov (United States)

Gotoh, Eisuke

2015-01-01

Chromosome analysis is a fundamental technique which is used in wide areas of cytogenetic study including karyotyping species, hereditary diseases diagnosis, or chromosome biology study. Chromosomes are usually prepared from mitotic cells arrested by colcemid block protocol. However, obtaining mitotic chromosomes is often hampered under several circumstances. As a result, cytogenetic analysis will be sometimes difficult or even impossible in such cases. Premature chromosome condensation (PCC) (see Note 1) is an alternative method that has proved to be a unique and useful way in chromosome analysis. Former, PCC has been achieved following cell fusion method (cell-fusion PCC) mediated either by fusogenic viruses (e.g., Sendai virus) or cell fusion chemicals (e.g., polyethylene glycol), but the cell fusion PCC has several drawbacks. The novel drug-induced PCC using protein phosphatase inhibitors was introduced about 20 years ago. This method is much simpler and easier even than the conventional mitotic chromosome preparation protocol use with colcemid block and furthermore obtained PCC index (equivalent to mitotic index for metaphase chromosome) is usually much higher than colcemid block method. Moreover, this method allows the interphase chromatin to be condensed to visualize like mitotic chromosomes. Therefore drug-induced PCC has opened the way for chromosome analysis not only in metaphase chromosomes but also in interphase chromatin. The drug-induced PCC has thus proven the usefulness in cytogenetics and other cell biology fields. For this second edition version, updated modifications/changes are supplemented in Subheadings 2, 3, and 4, and a new section describing the application of PCC in chromosome science fields is added with citation of updated references.

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

Evidence for an asthma risk locus on chromosome Xp: a replication linkage study

DEFF Research Database (Denmark)

Brasch-Andersen, C; Møller, M U; Haagerup, A

2008-01-01

replication sample as used in the present study. The aim of the study was to replicate linkage to candidate regions for asthma in an independent Danish sample. METHODS: We performed a replication study investigating linkage to candidate regions for asthma on chromosomes 1p36.31-p36.21, 5q15-q23.2, 6p24.3-p22...... studies have been carried out the results are still conflicting and call for replication experiments. A Danish genome-wide scan has prior reported evidence for candidate regions for asthma susceptibility genes on chromosomes 1p, 5q, 6p, 12q and Xp. Linkage to chromosome 12q was later confirmed in the same.......3, and Xp22.31-p11.4 using additional markers in an independent set of 136 Danish asthmatic sib pair families. RESULTS: Nonparametric multipoint linkage analyses yielded suggestive evidence for linkage to asthma to chromosome Xp21.2 (MLS 2.92) but failed to replicate linkage to chromosomes 1p36.31-p36.21, 5...

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)

[Introduction of hexaploid of Chinese narcissus and analysis of its chromosome change].

Science.gov (United States)

Wang, Rui; Zhang, Ya Nan; Wang, Ya Ying; Tian, Hui Qiao

2007-06-01

Anthers of Chinese narcissus (Narcissus tazetta L. var chinesis Roem) were used as explants for callus induction and plant regeneration. About 80% anthers produced callus and 28% of the callus differentiated out bulbs, making a good experiment system of tissue culture of Chinese narcissus for further cellular and gene engineering. The 700 callus were treated by 0.5% colchicin for 5-6 days and then transformed into a MS medium containing 3 mg/L 6-BA to induce differentiation. 90 bulbs were obtained and 55 bulbs among them were checked the chromosome number from their root tips for three times. 29 bulbs (53%, 29/55) still kept triploidy and the most cells of root tips contained 30 chromosomes. 22 bulbs (40%, 22/55) displayed aneuploidy and the most cells of its root tips contained 10-50 chromosomes. 4 bulbs displayed hexaploidy and contained 60 chromosomes. After three months growing, the cells of root tips containing aneuploidy chromosomes disappeared, and the bulbs became triploidy. The chromosomes of 4 hexaploidy bulbs did not changed during three checks. The origin and disappearance of aneuploidy cells of Chinese narcissus after treated by colchicin were discussed.

Fish Karyome version 2.1: a chromosome database of fishes and other aquatic organisms.

Science.gov (United States)

Nagpure, Naresh Sahebrao; Pathak, Ajey Kumar; Pati, Rameshwar; Rashid, Iliyas; Sharma, Jyoti; Singh, Shri Prakash; Singh, Mahender; Sarkar, Uttam Kumar; Kushwaha, Basdeo; Kumar, Ravindra; Murali, S

2016-01-01

A voluminous information is available on karyological studies of fishes; however, limited efforts were made for compilation and curation of the available karyological data in a digital form. 'Fish Karyome' database was the preliminary attempt to compile and digitize the available karyological information on finfishes belonging to the Indian subcontinent. But the database had limitations since it covered data only on Indian finfishes with limited search options. Perceiving the feedbacks from the users and its utility in fish cytogenetic studies, the Fish Karyome database was upgraded by applying Linux, Apache, MySQL and PHP (pre hypertext processor) (LAMP) technologies. In the present version, the scope of the system was increased by compiling and curating the available chromosomal information over the globe on fishes and other aquatic organisms, such as echinoderms, molluscs and arthropods, especially of aquaculture importance. Thus, Fish Karyome version 2.1 presently covers 866 chromosomal records for 726 species supported with 253 published articles and the information is being updated regularly. The database provides information on chromosome number and morphology, sex chromosomes, chromosome banding, molecular cytogenetic markers, etc. supported by fish and karyotype images through interactive tools. It also enables the users to browse and view chromosomal information based on habitat, family, conservation status and chromosome number. The system also displays chromosome number in model organisms, protocol for chromosome preparation and allied techniques and glossary of cytogenetic terms. A data submission facility has also been provided through data submission panel. The database can serve as a unique and useful resource for cytogenetic characterization, sex determination, chromosomal mapping, cytotaxonomy, karyo-evolution and systematics of fishes. Database URL: http://mail.nbfgr.res.in/Fish_Karyome. © The Author(s) 2016. Published by Oxford University Press.

Mitotic chromosome condensation in vertebrates

International Nuclear Information System (INIS)

Vagnarelli, Paola

2012-01-01

Work from several laboratories over the past 10–15 years has revealed that, within the interphase nucleus, chromosomes are organized into spatially distinct territories [T. Cremer, C. Cremer, Chromosome territories, nuclear architecture and gene regulation in mammalian cells, Nat. Rev. Genet. 2 (2001) 292–301 and T. Cremer, M. Cremer, S. Dietzel, S. Muller, I. Solovei, S. Fakan, Chromosome territories—a functional nuclear landscape, Curr. Opin. Cell Biol. 18 (2006) 307–316]. The overall compaction level and intranuclear location varies as a function of gene density for both entire chromosomes [J.A. Croft, J.M. Bridger, S. Boyle, P. Perry, P. Teague,W.A. Bickmore, Differences in the localization and morphology of chromosomes in the human nucleus, J. Cell Biol. 145 (1999) 1119–1131] and specific chromosomal regions [N.L. Mahy, P.E. Perry, S. Gilchrist, R.A. Baldock, W.A. Bickmore, Spatial organization of active and inactive genes and noncoding DNA within chromosome territories, J. Cell Biol. 157 (2002) 579–589] (Fig. 1A, A'). In prophase, when cyclin B activity reaches a high threshold, chromosome condensation occurs followed by Nuclear Envelope Breakdown (NEB) [1]. At this point vertebrate chromosomes appear as compact structures harboring an attachment point for the spindle microtubules physically recognizable as a primary constriction where the two sister chromatids are held together. The transition from an unshaped interphase chromosome to the highly structured mitotic chromosome (compare Figs. 1A and B) has fascinated researchers for several decades now; however a definite picture of how this process is achieved and regulated is not yet in our hands and it will require more investigation to comprehend the complete process. From a biochemical point of view a vertebrate mitotic chromosomes is composed of DNA, histone proteins (60%) and non-histone proteins (40%) [6]. I will discuss below what is known to date on the contribution of these two different

Mitotic chromosome condensation in vertebrates

Energy Technology Data Exchange (ETDEWEB)

Vagnarelli, Paola, E-mail: P.Vagnarelli@ed.ac.uk

2012-07-15

Work from several laboratories over the past 10-15 years has revealed that, within the interphase nucleus, chromosomes are organized into spatially distinct territories [T. Cremer, C. Cremer, Chromosome territories, nuclear architecture and gene regulation in mammalian cells, Nat. Rev. Genet. 2 (2001) 292-301 and T. Cremer, M. Cremer, S. Dietzel, S. Muller, I. Solovei, S. Fakan, Chromosome territories-a functional nuclear landscape, Curr. Opin. Cell Biol. 18 (2006) 307-316]. The overall compaction level and intranuclear location varies as a function of gene density for both entire chromosomes [J.A. Croft, J.M. Bridger, S. Boyle, P. Perry, P. Teague,W.A. Bickmore, Differences in the localization and morphology of chromosomes in the human nucleus, J. Cell Biol. 145 (1999) 1119-1131] and specific chromosomal regions [N.L. Mahy, P.E. Perry, S. Gilchrist, R.A. Baldock, W.A. Bickmore, Spatial organization of active and inactive genes and noncoding DNA within chromosome territories, J. Cell Biol. 157 (2002) 579-589] (Fig. 1A, A'). In prophase, when cyclin B activity reaches a high threshold, chromosome condensation occurs followed by Nuclear Envelope Breakdown (NEB) [1]. At this point vertebrate chromosomes appear as compact structures harboring an attachment point for the spindle microtubules physically recognizable as a primary constriction where the two sister chromatids are held together. The transition from an unshaped interphase chromosome to the highly structured mitotic chromosome (compare Figs. 1A and B) has fascinated researchers for several decades now; however a definite picture of how this process is achieved and regulated is not yet in our hands and it will require more investigation to comprehend the complete process. From a biochemical point of view a vertebrate mitotic chromosomes is composed of DNA, histone proteins (60%) and non-histone proteins (40%) [6]. I will discuss below what is known to date on the contribution of these two different classes

Dissection of a locus on mouse chromosome 5 reveals arthritis promoting and inhibitory genes

DEFF Research Database (Denmark)

Lindvall, Therese; Karlsson, Jenny; Holmdahl, Rikard

2009-01-01

with Eae39 congenic- and sub-interval congenic mice, carrying RIIIS/J genes on the B10.RIII genetic background, revealed three loci within Eae39 that control disease and anti-collagen antibody titers. Two of the loci promoted disease and the third locus was protecting from collagen induced arthritis...... development. By further breeding of mice with small congenic fragments, we identified a 3.2 Megabasepair (Mbp) interval that regulates disease. CONCLUSIONS: Disease promoting- and protecting genes within the Eae39 locus on mouse chromosome 5, control susceptibility to collagen induced arthritis. A disease......-protecting locus in the telomeric part of Eae39 results in lower anti-collagen antibody responses. The study shows the importance of breeding sub-congenic mouse strains to reveal genetic effects on complex diseases....

CHROMOSOMAL MULTIPLICITY IN BURKHOLDERIA CEPACIA

Science.gov (United States)

We have used CHEF gel electrophoresis to screen preparations of large DNA from different Burkholderia cepacia isolates for the presence of DNA species corresponding to the linearized forms of the three chromosomes of 3.4,2.5, and 0.9 Mb identified in B. cepacia strain 17616. DNA ...

Addition of Aegilops U and M Chromosomes Affects Protein and Dietary Fiber Content of Wholemeal Wheat Flour

Directory of Open Access Journals (Sweden)

Marianna Rakszegi

2017-09-01

Full Text Available Cereal grain fiber is an important health-promoting component in the human diet. One option to improve dietary fiber content and composition in wheat is to introduce genes from its wild relatives Aegilops biuncialis and Aegilops geniculata. This study showed that the addition of chromosomes 2Ug, 4Ug, 5Ug, 7Ug, 2Mg, 5Mg, and 7Mg of Ae. geniculata and 3Ub, 2Mb, 3Mb, and 7Mb of Ae. biuncialis into bread wheat increased the seed protein content. Chromosomes 1Ug and 1Mg increased the proportion of polymeric glutenin proteins, while the addition of chromosomes 1Ub and 6Ub led to its decrease. Both Aegilops species had higher proportions of β-glucan compared to arabinoxylan (AX than wheat lines, and elevated β-glucan content was also observed in wheat chromosome addition lines 5U, 7U, and 7M. The AX content in wheat was increased by the addition of chromosomes 5Ug, 7Ug, and 1Ub while water-soluble AX was increased by the addition of chromosomes 5U, 5M, and 7M, and to a lesser extent by chromosomes 3, 4, 6Ug, and 2Mb. Chromosomes 5Ug and 7Mb also affected the structure of wheat AX, as shown by the pattern of oligosaccharides released by digestion with endoxylanase. These results will help to map genomic regions responsible for edible fiber content in Aegilops and will contribute to the efficient transfer of wild alleles in introgression breeding programs to obtain wheat varieties with improved health benefits.Key Message: Addition of Aegilops U- and M-genome chromosomes 5 and 7 improves seed protein and fiber content and composition in wheat.

Chromosomal rearrangement interferes with meiotic X chromosome inactivation

Czech Academy of Sciences Publication Activity Database

Homolka, David; Ivánek, Robert; Čapková, Jana; Jansa, Petr; Forejt, Jiří

2007-01-01

Roč. 17, č. 10 (2007), s. 1431-1437 ISSN 1088-9051 R&D Projects: GA MŠk(CZ) 1M0520; GA ČR GA301/06/1334; GA ČR GA301/07/1383 Grant - others:Howard Hughes Medical Institute(US) HHMI 55000306 Institutional research plan: CEZ:AV0Z50520514 Keywords : chromosomal translocations * meiotic X chromosome inactivation * spermatogenesis Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 11.224, year: 2007

Chromosome banding pattern retrieves an independent origin of 2n = 50 chromosome populations of Nannospalax xanthodon from Turkey

Czech Academy of Sciences Publication Activity Database

Arslan, A.; Zima, Jan

2015-01-01

Roč. 80, č. 5 (2015), s. 440-445 ISSN 1616-5047 Institutional support: RVO:68081766 Keywords : Karyotype * Chromosomal races * Mole rats * Anatolia Subject RIV: EG - Zoology Impact factor: 1.595, year: 2015

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.

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)

Analysis of the Ceratitis capitata y chromosome using in situ hybridization to mitotic chromosomes

International Nuclear Information System (INIS)

Willhoeft, U.; Franz, G.

1998-01-01

In Ceratitis capitata the Y chromosome is responsible for sex-determination. We used fluorescence in situ hybridization (FISH) for cytogenetic analysis of mitotic chromosomes. FISH with the wild-type strain EgyptII and two repetitive DNA probes enabled us to differentiate between the short and the long arm of the Y chromosome and gives a much better resolution than C-banding of mitotic chromosomes. We identified the Y-chromosomal breakpoints in Y-autosome translocations using FISH. Even more complex rearrangements i.e. deletions and insertions in some translocation strains were detected by this method. A strategy for mapping the primary sex determination factor in Ceratitis capitata by FISH is presented. (author)

Design and validation of a highly discriminatory 10-locus Y-chromosome STR multiplex system

KAUST Repository

D'Amato, Marí a Eugenia; Bajic, Vladimir B.; Davison, Sean P.

2011-01-01

The Y-chromosome STRs (short tandem repeat) markers are routinely utilized in the resolution of forensic casework related to sexual assault. For this, the forensic community has adopted a set of eleven (core) Y-STR that is incorporated in all

Chromosome 11q13.5 variant associated with childhood eczema: an effect supplementary to filaggrin mutations.

LENUS (Irish Health Repository)

O'Regan, Grainne M

2012-02-01

BACKGROUND: Atopic eczema is a common inflammatory skin disease with multifactorial etiology. The genetic basis is incompletely understood; however, loss of function mutations in the filaggrin gene (FLG) are the most significant and widely replicated genetic risk factor reported to date. The first genome-wide association study in atopic eczema recently identified 2 novel genetic variants in association with eczema susceptibility: a single nucleotide polymorphism on chromosome 11q13.5 (rs7927894) and a single nucleotide polymorphism (rs877776) within the gene encoding hornerin on chromosome 1q21. OBJECTIVE: To test the association of these 2 novel variants with pediatric eczema and to investigate their interaction with FLG null mutations. METHODS: Case-control study to investigate the association of rs7927894, rs877776 and the 4 most prevalent FLG null mutations with moderate-severe eczema in 511 Irish pediatric cases and 1000 Irish controls. Comprehensive testing for interaction between each of the loci was also performed. RESULTS: The association between rs7927894 and atopic eczema was replicated in this population (P = .0025, chi(2) test; odds ratio, 1.27; 95% CI, 1.09-1.49). The 4 most common FLG null variants were strongly associated with atopic eczema (P = 1.26 x 10(-50); combined odds ratio, 5.81; 95% CI, 4.51-7.49). Interestingly, the rs7927894 association was independent of the well-established FLG risk alleles and may be multiplicative in its effect. There was no significant association between rs877776 and pediatric eczema in this study. CONCLUSION: Single nucleotide polymorphism rs7927894 appears to mark a genuine eczema susceptibility locus that will require further elucidation through fine mapping and functional analysis.

Numerically abnormal chromosome constitutions in humans

Energy Technology Data Exchange (ETDEWEB)

NONE

1993-12-31

Chapter 24, discusses numerically abnormal chromosome constitutions in humans. This involves abnormalities of human chromosome number, including polyploidy (when the number of sets of chromosomes increases) and aneuploidy (when the number of individual normal chromosomes changes). Chapter sections discuss the following chromosomal abnormalities: human triploids, imprinting and uniparental disomy, human tetraploids, hydatidiform moles, anomalies caused by chromosomal imbalance, 13 trisomy (D{sub 1} trisomy, Patau syndrome), 21 trisomy (Down syndrome), 18 trisomy syndrome (Edwards syndrome), other autosomal aneuploidy syndromes, and spontaneous abortions. The chapter concludes with remarks on the nonrandom participation of chromosomes in trisomy. 69 refs., 3 figs., 4 tabs.

A simple strategy for subcloning and amplifying random multimegabase subchromosomal acentric DNA fragments as double minute chromosomes

International Nuclear Information System (INIS)

Hahn, P.J.; Giddings, L.; Lane, M.J.

1989-01-01

Restriction mapping of relatively large genomes (e.g. human) utilizing randomly generated DNA segments requires high mapping redundancy to successfully organize 'contigs' to represent the entire genome. The number of independent DNA segment maps required is dependent on the average size of a mapping segment; the larger the segment, the fewer required. The authors have developed a strategy for subcloning intact multimegabase subchromosomal fragments as double minute chromosomes. Such fragments could serve as primary mapping elements or as adjunct (linking) fragments to rapidly connect already existent contigs generated using yeast artificial chromosomes or cosmids. They present several lines of evidence supporting the viability of this approach. (1) X-ray treated EMT-6 mouse cells (7.5 Gr.) which are selected over several months with increasing levels of methotrexate (MTX) contain highly amplified circular DNA molecules (double minutes) which include the dihydrofolate reductase (DHFR) gene in a size range between 1,000 and 3,500 kilobases as determined by pulsed-field gel electrophoresis and these acentric chromosomal fragments have been stably maintained in culture for at least a year. (2) Preliminary data based on experiments involving fusion of X-irradiated Chinese Hamster Ovary (CH0 DG44) cells containing randomly inserted cotransfected Neomycin resistance and DHFR genes to mouse EMT-6 cells shows that the linked genes can be readily cotransferred as acentric subchromosomal fragment(s) suitable for gene amplification. (3) The studies of CHO cells with cell fusion transferred X-ray induced chromosomal fragments containing the natural CHO DHFR gene suggest that transferred chromosome fragments undergo gene amplification much more readily than nonfragmented endogenous DHFR genes

Clinical Utility of the DSM-5 Alternative Model of Personality Disorders

DEFF Research Database (Denmark)

Bach, Bo; Markon, Kristian; Simonsen, Erik

2015-01-01

In Section III, Emerging Measures and Models, DSM-5 presents an Alternative Model of Personality Disorders, which is an empirically based model of personality pathology measured with the Level of Personality Functioning Scale (LPFS) and the Personality Inventory for DSM-5 (PID-5). These novel...... instruments assess level of personality impairment and pathological traits. Objective. A number of studies have supported the psychometric qualities of the LPFS and the PID-5, but the utility of these instruments in clinical assessment and treatment has not been extensively evaluated. The goal of this study...... was to evaluate the clinical utility of this alternative model of personality disorders. Method. We administered the LPFS and the PID-5 to psychiatric outpatients diagnosed with personality disorders and other nonpsychotic disorders. The personality profiles of six characteristic patients were inspected...

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

Single-molecule sequencing and Hi-C-based proximity-guided assembly of amaranth (Amaranthus hypochondriacus) chromosomes provide insights into genome evolution

KAUST Repository

Lightfoot, D. J.; Jarvis, David Erwin; Ramaraj, T.; Lee, R.; Jellen, E. N.; Maughan, P. J.

2017-01-01

Background: Amaranth (Amaranthus hypochondriacus) was a food staple among the ancient civilizations of Central and South America that has recently received increased attention due to the high nutritional value of the seeds, with the potential to help alleviate malnutrition and food security concerns, particularly in arid and semiarid regions of the developing world. Here, we present a reference-quality assembly of the amaranth genome which will assist the agronomic development of the species.Results: Utilizing single-molecule, real-time sequencing (Pacific Biosciences) and chromatin interaction mapping (Hi-C) to close assembly gaps and scaffold contigs, respectively, we improved our previously reported Illumina-based assembly to produce a chromosome-scale assembly with a scaffold N50 of 24.4 Mb. The 16 largest scaffolds contain 98% of the assembly and likely represent the haploid chromosomes (n = 16). To demonstrate the accuracy and utility of this approach, we produced physical and genetic maps and identified candidate genes for the betalain pigmentation pathway. The chromosome-scale assembly facilitated a genome-wide syntenic comparison of amaranth with other Amaranthaceae species, revealing chromosome loss and fusion events in amaranth that explain the reduction from the ancestral haploid chromosome number (n = 18) for a tetraploid member of the Amaranthaceae. as major evolutionary events in the 2n = 32 amaranths and clearly establish the homoeologous relationship among most of the subgenome chromosomes, which will facilitate future investigations of intragenomic changes that occurred post polyploidization.

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

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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

MURCS Association with Partial Duplication of the Distal Long Chromosome 5 and Unilateral Ovarian Agenesis

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Anna Dabkowska-Huc

2013-01-01

Full Text Available A combination of the congenital abnormalities, Müllerian duct aplasia, renal aplasia, and cervicothoracic somite dysplasia, is defined as the MURCS association. Various genetic defects have been described in the MURCS association so far, yet the unambiguous molecular basis of these disorders has not been established. We report the case of an 18-year-old woman who presented with primary amenorrhea, right kidney, Arnold-Chiari malformation, and Klippel-Feil syndrome. In addition, the patient showed the following unusual features: right ovarian and Skenes gland agenesis, cubitus valgus with hyperextension and decreased range of motion at elbows, and facial changes. Moreover, the performed DNA analysis showed interstitial duplication in chromosome 5 (5q35.1. In the duplicated region, there are genes whose function is not well known. It is thought that they have an influence on the early stages of development and their joining in the later period can lead to neoplastic disorders, especially leukemias.

Molecular fundamentals of chromosomal mutagenesis

International Nuclear Information System (INIS)

Ganassi, E.Eh.; Zaichkina, S.I.; Malakhova, L.V.

1987-01-01

Precise quantitative correlation between the yield of chromosome structure damages and the yield of DNA damages is shown when comparing data on molecular and cytogenetic investigations carried out in cultural Mammalia cells. As the chromosome structure damage is to be connected with the damage of its carcass structure, then it is natural that DNA damage in loop regions is not to affect considerably the structure, while DNA damage lying on the loop base and connected with the chromosome carcass is to play a determining role in chromosomal mutagenesis. This DNA constitutes 1-2% from the total quantity of nuclear DNA. If one accepts that damages of these regions of DNA are ''hot'' points of chromosomal mutagenesis, then it becomes clear why 1-2% of preparation damages in a cell are realized in chromosome structural damages

Phenotypic variation within European carriers of the Y-chromosomal gr/gr deletion is independent of Y-chromosomal background

DEFF Research Database (Denmark)

Krausz, C; Giachini, C; Xue, Y

2008-01-01

of duplications and the Y-chromosomal haplogroup were characterised. Although the study had good power to detect factors that accounted for >or=5.5% of the variation in sperm concentration, no such factor was found. A negative effect of gr/gr deletions followed by b2/b4 duplication was found within...

Exchange of core chromosomes and horizontal transfer of lineage-specific chromosomes in Fusarium oxysporum

NARCIS (Netherlands)

Vlaardingerbroek, I.; Beerens, B.; Rose, L.; Fokkens, L.; Cornelissen, B.J.C.; Rep, M.

2016-01-01

Horizontal transfer of supernumerary or lineage-specific (LS) chromosomes has been described in a number of plant pathogenic filamentous fungi. So far it was not known whether transfer is restricted to chromosomes of certain size or properties, or whether 'core' chromosomes can also undergo

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

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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.

Chromosome Territories

OpenAIRE

Cremer, Thomas; Cremer, Marion

2010-01-01

Chromosome territories (CTs) constitute a major feature of nuclear architecture. In a brief statement, the possible contribution of nuclear architecture studies to the field of epigenomics is considered, followed by a historical account of the CT concept and the final compelling experimental evidence of a territorial organization of chromosomes in all eukaryotes studied to date. Present knowledge of nonrandom CT arrangements, of the internal CT architecture, and of structural interactions wit...

Recurrence risk in de novo structural chromosomal rearrangements.

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Röthlisberger, Benno; Kotzot, Dieter

2007-08-01

According to the textbook of Gardner and Sutherland [2004], the standard on genetic counseling for chromosome abnormalities, the recurrence risk of de novo structural or combined structural and numeric chromosome rearrangements is less than 0.5-2% and takes into account recurrence by chance, gonadal mosaicism, and somatic-gonadal mosaicism. However, these figures are roughly estimated and neither any systematic study nor exact or evidence-based risk calculations are available. To address this question, an extensive literature search was performed and surprisingly only 29 case reports of recurrence of de novo structural or combined structural and numeric chromosomal rearrangements were found. Thirteen of them were with a trisomy 21 due to an i(21q) replacing one normal chromosome 21. In eight of them low-level mosaicism in one of the parents was found either in fibroblasts or in blood or in both. As a consequence of the low number of cases and theoretical considerations (clinical consequences, mechanisms of formation, etc.), the recurrence risk should be reduced to less than 1% for a de novo i(21q) and to even less than 0.3% for all other de novo structural or combined structural and numeric chromosomal rearrangements. As the latter is lower than the commonly accepted risk of approximately 0.3% for indicating an invasive prenatal diagnosis and as the risk of abortion of a healthy fetus after chorionic villous sampling or amniocentesis is higher than approximately 0.5%, invasive prenatal investigation in most cases is not indicated and should only be performed if explicitly asked by the parents subsequent to appropriate genetic counseling. (c) 2007 Wiley-Liss, Inc.

Chromosomal Evolution in Chiroptera.

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Sotero-Caio, Cibele G; Baker, Robert J; Volleth, Marianne

2017-10-13

Chiroptera is the second largest order among mammals, with over 1300 species in 21 extant families. The group is extremely diverse in several aspects of its natural history, including dietary strategies, ecology, behavior and morphology. Bat genomes show ample chromosome diversity (from 2n = 14 to 62). As with other mammalian orders, Chiroptera is characterized by clades with low, moderate and extreme chromosomal change. In this article, we will discuss trends of karyotypic evolution within distinct bat lineages (especially Phyllostomidae, Hipposideridae and Rhinolophidae), focusing on two perspectives: evolution of genome architecture, modes of chromosomal evolution, and the use of chromosome data to resolve taxonomic problems.

Chromosomal Evolution in Chiroptera

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Cibele G. Sotero-Caio

2017-10-01

Full Text Available Chiroptera is the second largest order among mammals, with over 1300 species in 21 extant families. The group is extremely diverse in several aspects of its natural history, including dietary strategies, ecology, behavior and morphology. Bat genomes show ample chromosome diversity (from 2n = 14 to 62. As with other mammalian orders, Chiroptera is characterized by clades with low, moderate and extreme chromosomal change. In this article, we will discuss trends of karyotypic evolution within distinct bat lineages (especially Phyllostomidae, Hipposideridae and Rhinolophidae, focusing on two perspectives: evolution of genome architecture, modes of chromosomal evolution, and the use of chromosome data to resolve taxonomic problems.

GSK-3 inhibitors induce chromosome instability

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Staples Oliver D

2007-08-01

Full Text Available Abstract Background Several mechanisms operate during mitosis to ensure accurate chromosome segregation. However, during tumour evolution these mechanisms go awry resulting in chromosome instability. While several lines of evidence suggest that mutations in adenomatous polyposis coli (APC may promote chromosome instability, at least in colon cancer, the underlying mechanisms remain unclear. Here, we turn our attention to GSK-3 – a protein kinase, which in concert with APC, targets β-catenin for proteolysis – and ask whether GSK-3 is required for accurate chromosome segregation. Results To probe the role of GSK-3 in mitosis, we inhibited GSK-3 kinase activity in cells using a panel of small molecule inhibitors, including SB-415286, AR-A014418, 1-Azakenpaullone and CHIR99021. Analysis of synchronised HeLa cells shows that GSK-3 inhibitors do not prevent G1/S progression or cell division. They do, however, significantly delay mitotic exit, largely because inhibitor-treated cells have difficulty aligning all their chromosomes. Although bipolar spindles form and the majority of chromosomes biorient, one or more chromosomes often remain mono-oriented near the spindle poles. Despite a prolonged mitotic delay, anaphase frequently initiates without the last chromosome aligning, resulting in chromosome non-disjunction. To rule out the possibility of "off-target" effects, we also used RNA interference to selectively repress GSK-3β. Cells deficient for GSK-3β exhibit a similar chromosome alignment defect, with chromosomes clustered near the spindle poles. GSK-3β repression also results in cells accumulating micronuclei, a hallmark of chromosome missegregation. Conclusion Thus, not only do our observations indicate a role for GSK-3 in accurate chromosome segregation, but they also raise the possibility that, if used as therapeutic agents, GSK-3 inhibitors may induce unwanted side effects by inducing chromosome instability.

Most ultraviolet irradiation induced mutations in the nematode Caenorhabditis elegans are chromosomal rearrangements

International Nuclear Information System (INIS)

Stewart, H.I.; Rosenbluth, R.E.; Baillie, D.L.

1991-01-01

In this study the utility of 254-nm ultraviolet light (UV) as a magnetic tool in C.elegans is determined. It is demonstrated that irradiation of adult hermaphrodites provides a simple method for the induction of heritable chromosomal rearrangements. A screening protocol was employed that identifies either recessive lethal mutations in the 40 map unit region balanced by the translocation eT1(III;V), or unc-36(III) duplications. Mutations were recovered in 3% of the chromosomes screened after a dose of 120 J/m 2 . This rate resembles that for 1500 R γ-ray-induced mutations selected in a similar manner. The mutations were classified either as lethals [mapping to Linkage Group (LG)III or LGV] or as putative unc-36 duplications. In contrast to the majority of UV-induced mutations analysed in micro-organisms, a large fraction of the C.elegans UV-induced mutations were found to be not simple intragenic lesions, but deficiencies for more than one adjacent gene or more complex events. Preliminary evidence for this conclusion came from the high frequency of mutations that had a dominant effect causing reduced numbers of adult progeny. Subsequently 6 out of 9 analysed LGV mutations were found to be deficiencies. Other specific rearrangements also identified were: one translocation, sT5(II;III), and two unc-36 duplications, sDp8 and sDp9. It was concluded that UV irradiation can easily be used as an additional tool for the analysis of C.elegans chromosomes, and that C.elegans should prove to be a useful organism in which to study the mechanisms whereby UV acts as a mutagen in cells of complex eukaryotes. (author). 46 refs.; 5 figs.; 4 tabs

Karyotyping and in situ chromosomal localization of rDNA sites in black cumin Bunium persicum (Boiss B. Fedtsch,1915 (Apiaceae

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R. K. Chahota

2011-11-01

Full Text Available The fluorescent in situ hybridization (FISH technique has been applied to somatic chromosomes in the medicinally important species, Bunium persicum, to elucidate its karyotypes. The bicolour FISH technique involving 18S-5.8S-26S and 5S ribosomal RNA genes as probes was used to assign physical localization and measurement of rDNA sites on homologous pairs of chromosomes. The two 18S-5.8S-26S rRNA gene sites were at the terminal regions of the short arms of the chromosomes 1 and 2 involving NOR region of chromosome 1. The 5S rDNA sites were found on subtelomeric region of the long arm of the chromosome number 5 and at interstitial regions of the short arm of chromosome 7. Based on direct visual analysis of chromosome length, morphology and position of FISH signals, a pioneer attempt has been made to construct metaphase karyotype in B. persicum, an endangered medicinal plant of North Western Himalayas.

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...

Prevalence of chromosomal abnormalities in Sri Lankan women with primary amenorrhea.

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Samarakoon, Lasitha; Sirisena, Nirmala D; Wettasinghe, Kalum T; Kariyawasam, Kariyawasam Warnakulathanthrige Jayani C; Jayasekara, Rohan W; Dissanayake, Vajira H W

2013-05-01

Chromosomal abnormalities are implicated in the etiology of primary amenorrhea. The underlying chromosomal aberrations are varied and regional differences have been reported. The objective of this study is to describe the prevalence of various types of chromosomal abnormalities in Sri Lankan women with primary amenorrhea. Medical records of all patients diagnosed with primary amenorrhea referred for cytogenetic analysis to two genetic centers in Sri Lanka from January 2005 to December 2011 were reviewed. Chromosome culture and karyotyping was performed on peripheral blood samples obtained from each patient. Data were analyzed using standard descriptive statistics. Altogether 338 patients with primary amenorrhea were karyotyped and mean age at testing was 20.5 years. Numerical and structural chromosomal abnormalities were noted in 115 (34.0%) patients which included 45,X Turner syndrome (10.7%), Turner syndrome variants (13.9%), XY females (6.5%), 45,X/46,XY (0.9%), 46,XX/46,XY (0.6%), 47,XXX (0.3%), 47,XX,+ mar (0.3%), 46,X,i(X)(p10) (0.3%), 46,XX with SRY gene translocation on X chromosome (0.3%) and 46,XX,inv(7)(p10;q11.2) (0.3%). Short stature, absent secondary sexual characteristics, neck webbing, cubitus valgus and broad chest with widely spaced nipples were commonly seen in patients with Turner syndrome and variant forms. Neck webbing and absent secondary sexual characteristics were significantly associated with classical Turner syndrome than variant forms. A considerable proportion of women with primary amenorrhea had chromosomal abnormalities. Mean age at testing was late suggesting delay in referral for karyotyping. Early referral for cytogenetic evaluation is recommended for the identification of underlying chromosomal aberrations in women with primary amenorrhea. © 2012 The Authors. Journal of Obstetrics and Gynaecology Research © 2012 Japan Society of Obstetrics and Gynecology.

Somatic association of telocentric chromosomes carrying homologous centromeres in common wheat.

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Mello-Sampayo, T

1973-01-01

Measurements of distances between telocentric chromosomes, either homologous or representing the opposite arms of a metacentric chromosome (complementary telocentrics), were made at metaphase in root tip cells of common wheat carrying two homologous pairs of complementary telocentrics of chromosome 1 B or 6 B (double ditelosomic 1 B or 6 B). The aim was to elucidate the relative locations of the telocentric chromosomes within the cell. The data obtained strongly suggest that all four telocentrics of chromosome 1 B or 6 B are spacially and simultaneously co-associated. In plants carrying two complementary (6 B (S) and 6 B (L)) and a non-related (5 B (L)) telocentric, only the complementary chromosomes were found to be somatically associated. It is thought, therefore, that the somatic association of chromosomes may involve more than two chromosomes in the same association and, since complementary telocentrics are as much associated as homologous, that the homology between centromeres (probably the only homologous region that exists between complementary telocentrics) is a very important condition for somatic association of chromosomes. The spacial arrangement of chromosomes was studied at anaphase and prophase and the polar orientation of chromosomes at prophase was found to resemble anaphase orientation. This was taken as good evidence for the maintenance of the chromosome arrangement - the Rabl orientation - and of the peripheral location of the centromere and its association with the nuclear membrane. Within this general arrangement homologous telocentric chromosomes were frequently seen to have their centromeres associated or directed towards each other. The role of the centromere in somatic association as a spindle fibre attachment and chromosome binder is discussed. It is suggested that for non-homologous chromosomes to become associated in root tips, the only requirement needed should be the homology of centromeres such as exists between complementary

CRISPR/Cas9-induced transgene insertion and telomere-associated truncation of a single human chromosome for chromosome engineering in CHO and A9 cells.

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Uno, Narumi; Hiramatsu, Kei; Uno, Katsuhiro; Komoto, Shinya; Kazuki, Yasuhiro; Oshimura, Mitsuo

2017-10-06

Chromosome engineering techniques including gene insertion, telomere-associated truncation and microcell-mediated chromosome transfer (MMCT) are powerful tools for generation of humanised model animal, containing megabase-sized genomic fragments. However, these techniques require two cell lines: homologous recombination (HR)-proficient DT40 cells for chromosome modification, and CHO cells for transfer to recipient cells. Here we show an improved technique using a combination of CRISPR/Cas9-induced HR in CHO and mouse A9 cells without DT40 cells following MMCT to recipient cells. Transgene insertion was performed in CHO cells with the insertion of enhanced green fluorescence protein (EGFP) using CRISPR/Cas9 and a circular targeting vector containing two 3 kb HR arms. Telomere-associated truncation was performed in CHO cells using CRISPR/Cas9 and a linearised truncation vector containing a single 7 kb HR arm at the 5' end, a 1 kb artificial telomere at the 3' end. At least 11% and 6% of the targeting efficiency were achieved for transgene insertion and telomere-associated truncation, respectively. The transgene insertion was also confirmed in A9 cells (29%). The modified chromosomes were transferrable to other cells. Thus, this CHO and A9 cell-mediated chromosome engineering using the CRISPR/Cas9 for direct transfer of the modified chromosome is a rapid technique that will facilitate chromosome manipulation.

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....

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)

Construction of physical maps for the sex-specific regions of papaya sex chromosomes

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Na Jong-Kuk

2012-05-01

Full Text Available Abstract Background Papaya is a major fruit crop in tropical and subtropical regions worldwide. It is trioecious with three sex forms: male, female, and hermaphrodite. Sex determination is controlled by a pair of nascent sex chromosomes with two slightly different Y chromosomes, Y for male and Yh for hermaphrodite. The sex chromosome genotypes are XY (male, XYh (hermaphrodite, and XX (female. The papaya hermaphrodite-specific Yh chromosome region (HSY is pericentromeric and heterochromatic. Physical mapping of HSY and its X counterpart is essential for sequencing these regions and uncovering the early events of sex chromosome evolution and to identify the sex determination genes for crop improvement. Results A reiterate chromosome walking strategy was applied to construct the two physical maps with three bacterial artificial chromosome (BAC libraries. The HSY physical map consists of 68 overlapped BACs on the minimum tiling path, and covers all four HSY-specific Knobs. One gap remained in the region of Knob 1, the only knob structure shared between HSY and X, due to the lack of HSY-specific sequences. This gap was filled on the physical map of the HSY corresponding region in the X chromosome. The X physical map consists of 44 BACs on the minimum tiling path with one gap remaining in the middle, due to the nature of highly repetitive sequences. This gap was filled on the HSY physical map. The borders of the non-recombining HSY were defined genetically by fine mapping using 1460 F2 individuals. The genetically defined HSY spanned approximately 8.5 Mb, whereas its X counterpart extended about 5.4 Mb including a 900 Kb region containing the Knob 1 shared by the HSY and X. The 8.5 Mb HSY corresponds to 4.5 Mb of its X counterpart, showing 4 Mb (89% DNA sequence expansion. Conclusion The 89% increase of DNA sequence in HSY indicates rapid expansion of the Yh chromosome after genetic recombination was suppressed 2–3 million years ago. The

Chromosome End Repair and Genome Stability in Plasmodium falciparum.

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Calhoun, Susannah F; Reed, Jake; Alexander, Noah; Mason, Christopher E; Deitsch, Kirk W; Kirkman, Laura A

2017-08-08

The human malaria parasite Plasmodium falciparum replicates within circulating red blood cells, where it is subjected to conditions that frequently cause DNA damage. The repair of DNA double-stranded breaks (DSBs) is thought to rely almost exclusively on homologous recombination (HR), due to a lack of efficient nonhomologous end joining. However, given that the parasite is haploid during this stage of its life cycle, the mechanisms involved in maintaining genome stability are poorly understood. Of particular interest are the subtelomeric regions of the chromosomes, which contain the majority of the multicopy variant antigen-encoding genes responsible for virulence and disease severity. Here, we show that parasites utilize a competitive balance between de novo telomere addition, also called "telomere healing," and HR to stabilize chromosome ends. Products of both repair pathways were observed in response to DSBs that occurred spontaneously during routine in vitro culture or resulted from experimentally induced DSBs, demonstrating that both pathways are active in repairing DSBs within subtelomeric regions and that the pathway utilized was determined by the DNA sequences immediately surrounding the break. In combination, these two repair pathways enable parasites to efficiently maintain chromosome stability while also contributing to the generation of genetic diversity. IMPORTANCE Malaria is a major global health threat, causing approximately 430,000 deaths annually. This mosquito-transmitted disease is caused by Plasmodium parasites, with infection with the species Plasmodium falciparum being the most lethal. Mechanisms underlying DNA repair and maintenance of genome integrity in P. falciparum are not well understood and represent a gap in our understanding of how parasites survive the hostile environment of their vertebrate and insect hosts. Our work examines DNA repair in real time by using single-molecule real-time (SMRT) sequencing focused on the subtelomeric

Chromosome aberrations of bone marrow cells in heavily exposed atomic bomb survivors

International Nuclear Information System (INIS)

Tanaka, Kimio; Kamada, Nanao; Kuramoto, Atsushi; Ohkita, Takeshi

1986-01-01

Seven hundred and ten bone marrow cells from 13 A-bomb survivors, who were heavily exposed to atomic radiation, were examined using chromosome banding method. An average frequency of chromosome aberrations was 17 %. The most common structural abnormality was translocation (47 %), followed by complex aberrations involving three or more chromosomes (32 %). These abnormalities were frequently seen in A-bomb survivors exposed to estimated doses of 3.5 - 4.0 Gy. Eighty two percent of the structural aberrations were stable. Diploid cells were seen in 0.4 % and tetraploid cells were seen in 0.7 %. The frequency of breakpoint sites was high in chromosomes 1 and 17; while it was low in chromosomes 3, 6, 9, and 11. Abnormal clones were seen in one of the 13 survivors. Chromosome aberrations common to the bone marrow cells and peripheral lymphocytes were not seen in the same individual. (Namekawa, K.)

Increased number of sex chromosomes affects height in a nonlinear fashion: a study of 305 patients with sex chromosome aneuploidy

DEFF Research Database (Denmark)

Ottesen, Anne-Marie; Aksglaede, Lise; Garn, Inger

2010-01-01

Tall stature and eunuchoid body proportions characterize patients with 47,XXY Klinefelter syndrome, whereas patients with 45,X Turner syndrome are characterized by impaired growth. Growth is relatively well characterized in these two syndromes, while few studies describe the growth of patients wi......,XXXX (n = 13), and -1.0 (-3.5 to -0.8) in 49,XXXXX (n = 3). Height increased with an increasing number of extra X or Y chromosomes, except in males with five, and in females with four or five sex chromosomes, consistent with a nonlinear effect on height....

Chromosome analysis of arsenic affected cattle

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S. Shekhar

2014-10-01

Full Text Available Aim: The aim was to study the chromosome analysis of arsenic affected cattle. Materials and Methods: 27 female cattle (21 arsenic affected and 6 normal were selected for cytogenetical study. The blood samples were collected, incubated, and cultured using appropriate media and specific methods. The samples were analyzed for chromosome number and morphology, relative length of the chromosome, arm ratio, and centromere index of X chromosome and chromosomal abnormalities in arsenic affected cattle to that of normal ones. Results: The diploid number of metaphase chromosomes in arsenic affected cattle as well as in normal cattle were all 2n=60, 58 being autosomes and 2 being sex chromosomes. From the centromeric position, karyotyping studies revealed that all the 29 pair of autosomes was found to be acrocentric or telocentric, and the sex chromosomes (XX were submetacentric in both normal and arsenic affected cattle. The relative length of all the autosome pairs and sex chrosomosome pair was found to be higher in normal than that of arsenic affected cattle. The mean arm ratio of X-chromosome was higher in normal than that of arsenic affected cattle, but it is reverse in case of centromere index value of X-chromosome. There was no significant difference of arm ratio and centromere index of X-chromosomes between arsenic affected and normal cattle. No chromosomal abnormalities were found in arsenic affected cattle. Conclusion: The chromosome analysis of arsenic affected cattle in West Bengal reported for the first time in this present study which may serve as a guideline for future studies in other species. These reference values will also help in comparison of cytological studies of arsenic affected cattle to that of various toxicants.

Risk of chromosomal abnormalities in early spontaneous abortion after assisted reproductive technology: a meta-analysis.

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Jun-Zhen Qin

Full Text Available BACKGROUND: Studies on the risk of chromosomal abnormalities in early spontaneous abortion after assisted reproductive technology (ART are relatively controversial and insufficient. Thus, to obtain a more precise evaluation of the risk of embryonic chromosomal abnormalities in first-trimester miscarriage after ART, we performed a meta-analysis of all available case-control studies relating to the cytogenetic analysis of chromosomal abnormalities in first-trimester miscarriage after ART. METHODS: Literature search in the electronic databases MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials (CENTRAL based on the established strategy. Meta-regression, subgroup analysis, and Galbraith plots were conducted to explore the sources of heterogeneity. RESULTS: A total of 15 studies with 1,896 cases and 1,186 controls relevant to the risk of chromosomal abnormalities in first- trimester miscarriage after ART, and 8 studies with 601 cases and 602 controls evaluating frequency of chromosome anomaly for maternal age≥35 versus <35 were eligible for the meta-analysis. No statistical difference was found in risk of chromosomally abnormal miscarriage compared to natural conception and the different types of ART utilized, whereas the risk of fetal aneuploidy significantly increased with maternal age≥35 (OR 2.88, 95% CI: 1.74-4.77. CONCLUSIONS: ART treatment does not present an increased risk for chromosomal abnormalities occurring in a first trimester miscarriage, but incidence of fetal aneuploidy could increase significantly with advancing maternal age.

Initiation at closely spaced replication origins in a yeast chromosome.

Science.gov (United States)

Brewer, B J; Fangman, W L

1993-12-10

Replication of eukaryotic chromosomes involves initiation at origins spaced an average of 50 to 100 kilobase pairs. In yeast, potential origins can be recognized as autonomous replication sequences (ARSs) that allow maintenance of plasmids. However, there are more ARS elements than active chromosomal origins. The possibility was examined that close spacing of ARSs can lead to inactive origins. Two ARSs located 6.5 kilobase pairs apart can indeed interfere with each other. Replication is initiated from one or the other ARS with equal probability, but rarely (< 5%) from both ARSs on the same DNA molecule.

Confirmation of the reported association of clonal chromosomal mosaicism with an increased risk of incident hematologic cancer.

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Ursula M Schick

Full Text Available Chromosomal abnormalities provide clinical utility in the diagnosis and treatment of hematologic malignancies, and may be predictive of malignant transformation in individuals without apparent clinical presentation of a hematologic cancer. In an effort to confirm previous reports of an association between clonal mosaicism and incident hematologic cancer, we applied the anomDetectBAF algorithm to call chromosomal anomalies in genotype data from previously conducted Genome Wide Association Studies (GWAS. The genotypes were initially collected from DNA derived from peripheral blood of 12,176 participants in the Group Health electronic Medical Records and Genomics study (eMERGE and the Women's Health Initiative (WHI. We detected clonal mosaicism in 169 individuals (1.4% and large clonal mosaic events (>2 mb in 117 (1.0% individuals. Though only 9.5% of clonal mosaic carriers had an incident diagnosis of hematologic cancer (multiple myeloma, myelodysplastic syndrome, lymphoma, or leukemia, the carriers had a 5.5-fold increased risk (95% CI: 3.3-9.3; p-value = 7.5×10(-11 of developing these cancers subsequently. Carriers of large mosaic anomalies showed particularly pronounced risk of subsequent leukemia (HR = 19.2, 95% CI: 8.9-41.6; p-value = 7.3×10(-14. Thus we independently confirm the association between detectable clonal mosaicism and hematologic cancer found previously in two recent publications.

Heterochromatin diversity and its co-localization with 5S and 45S rDNA sites in chromosomes of four Maxillaria species (Orchidaceae)

OpenAIRE

Cabral, Juliano S.; Felix, Leonardo P.; Guerra, Marcelo

2006-01-01

We investigated four orchids of the genus Maxillaria (M. discolor, M. acicularis, M. notylioglossa and M. desvauxiana) in regard to the position of heterochromatin blocks as revealed using chromomycin A3 (CMA) and 4'-6-diamidino-2-phenylindole (DAPI) fluorochrome staining and 5S and 45S rDNA sites using fluorescence in situ hybridization (FISH). The species showed differences in chromosome number and a diversified pattern of CMA+ and DAPI+ bands, including heteromorphism for CMA+ bands. The 5...

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

Chromosomal Bands Affected by Acute Oil Exposure and DNA Repair Errors

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Zock, Jan-Paul; Giraldo, Jesús; Pozo-Rodríguez, Francisco; Espinosa, Ana; Rodríguez-Trigo, Gema; Verea, Hector; Castaño-Vinyals, Gemma; Gómez, Federico P.; Antó, Josep M.; Coll, Maria Dolors; Barberà, Joan Albert; Fuster, Carme

2013-01-01

Background In a previous study, we showed that individuals who had participated in oil clean-up tasks after the wreckage of the Prestige presented an increase of structural chromosomal alterations two years after the acute exposure had occurred. Other studies have also reported the presence of DNA damage during acute oil exposure, but little is known about the long term persistence of chromosomal alterations, which can be considered as a marker of cancer risk. Objectives We analyzed whether the breakpoints involved in chromosomal damage can help to assess the risk of cancer as well as to investigate their possible association with DNA repair efficiency. Methods Cytogenetic analyses were carried out on the same individuals of our previous study and DNA repair errors were assessed in cultures with aphidicolin. Results Three chromosomal bands, 2q21, 3q27 and 5q31, were most affected by acute oil exposure. The dysfunction in DNA repair mechanisms, expressed as chromosomal damage, was significantly higher in exposed-oil participants than in those not exposed (p= 0.016). Conclusion The present study shows that breaks in 2q21, 3q27 and 5q31 chromosomal bands, which are commonly involved in hematological cancer, could be considered useful genotoxic oil biomarkers. Moreover, breakages in these bands could induce chromosomal instability, which can explain the increased risk of cancer (leukemia and lymphomas) reported in chronically benzene-exposed individuals. In addition, it has been determined that the individuals who participated in clean-up of the oil spill presented an alteration of their DNA repair mechanisms two years after exposure. PMID:24303039

Estimation of EuroQol 5-Dimensions health status utility values in hereditary angioedema.

Science.gov (United States)

Aygören-Pürsün, Emel; Bygum, Anette; Beusterien, Kathleen; Hautamaki, Emily; Sisic, Zlatko; Boysen, Henrik B; Caballero, Teresa

2016-01-01

To estimate health status utility (preference) weights for hereditary angioedema (HAE) during an attack and between attacks using data from the Hereditary Angioedema Burden of Illness Study in Europe (HAE-BOIS-Europe) survey. Utility measures quantitatively describe the net impact of a condition on a patient's life; a score of 0.0 reflects death and 1.0 reflects full health. The HAE-BOIS-Europe was a cross-sectional survey conducted in Spain, Germany, and Denmark to assess the real-world experience of HAE from the patient perspective. Survey items that overlapped conceptually with the EuroQol 5-Dimensions (EQ-5D) domains (pain/discomfort, mobility, self-care, usual activities, and anxiety/depression) were manually crosswalked to the corresponding UK population-based EQ-5D utility weights. EQ-5D utilities were computed for each respondent in the HAE-BOIS-Europe survey for acute attacks and between attacks. Overall, a total of 111 HAE-BOIS-Europe participants completed all selected survey items and thus allowed for computation of EQ-5D-based utilities. The mean utilities for an HAE attack and between attacks were 0.44 and 0.72, respectively. Utilities for an acute attack were dependent on the severity of pain of the last attack (0.61 for no pain or mild pain, 0.47 for moderate pain, and 0.08 for severe pain). There were no significant differences across countries. Mean utilities derived from the study approach compare sensibly with other disease states for both acute attacks and between attacks. The impacts of HAE translate into substantial health status disutilities associated with acute attacks as well as between attacks, documenting that the detrimental effects of HAE are meaningful from the patient perspective. Results were consistent across countries with regard to pain severity and in comparison to similar disease states. The results can be used to raise awareness of HAE as a serious disease with wide-ranging personal and social impacts.

Clonal evolution through loss of chromosomes and subsequent polyploidization in chondrosarcoma.

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Linda Olsson

Full Text Available Near-haploid chromosome numbers have been found in less than 1% of cytogenetically reported tumors, but seem to be more common in certain neoplasms including the malignant cartilage-producing tumor chondrosarcoma. By a literature survey of published karyotypes from chondrosarcomas we could confirm that loss of chromosomes resulting in hyperhaploid-hypodiploid cells is common and that these cells may polyploidize. Sixteen chondrosarcomas were investigated by single nucleotide polymorphism (SNP array and the majority displayed SNP patterns indicative of a hyperhaploid-hypodiploid origin, with or without subsequent polyploidization. Except for chromosomes 5, 7, 19, 20 and 21, autosomal loss of heterozygosity was commonly found, resulting from chromosome loss and subsequent duplication of monosomic chromosomes giving rise to uniparental disomy. Additional gains, losses and rearrangements of genetic material, and even repeated rounds of polyploidization, may affect chondrosarcoma cells resulting in highly complex karyotypes. Loss of chromosomes and subsequent polyploidization was not restricted to a particular chondrosarcoma subtype and, although commonly found in chondrosarcoma, binucleated cells did not seem to be involved in these events.

Clonal evolution through loss of chromosomes and subsequent polyploidization in chondrosarcoma.

Science.gov (United States)

Olsson, Linda; Paulsson, Kajsa; Bovée, Judith V M G; Nord, Karolin H

2011-01-01

Near-haploid chromosome numbers have been found in less than 1% of cytogenetically reported tumors, but seem to be more common in certain neoplasms including the malignant cartilage-producing tumor chondrosarcoma. By a literature survey of published karyotypes from chondrosarcomas we could confirm that loss of chromosomes resulting in hyperhaploid-hypodiploid cells is common and that these cells may polyploidize. Sixteen chondrosarcomas were investigated by single nucleotide polymorphism (SNP) array and the majority displayed SNP patterns indicative of a hyperhaploid-hypodiploid origin, with or without subsequent polyploidization. Except for chromosomes 5, 7, 19, 20 and 21, autosomal loss of heterozygosity was commonly found, resulting from chromosome loss and subsequent duplication of monosomic chromosomes giving rise to uniparental disomy. Additional gains, losses and rearrangements of genetic material, and even repeated rounds of polyploidization, may affect chondrosarcoma cells resulting in highly complex karyotypes. Loss of chromosomes and subsequent polyploidization was not restricted to a particular chondrosarcoma subtype and, although commonly found in chondrosarcoma, binucleated cells did not seem to be involved in these events.

New chromosome characteristics of the monozoic tapeworm Caryophyllaeus laticeps (Cestoda, Caryophyllidea

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Bombarová M.

2015-12-01

Full Text Available The karyotype of a caryophyllidean tapeworm Caryophyllaeus laticeps (Pallas, 1781 from the freshwater bream Abramis brama (L. caught in the Slovak part of the River Tisa, was described and originally inspected for amount of heterochromatin and its chromosome localization. The chromosome set comprised nine metacentric and one submetacentric (No. 3 pairs (2n = 20. The chromosomes were up to 12.0 ± 2.5 μm long and the mean total length of haploid genome (TLC reached 80.6 μm that represents one of the highest yet recorded values among tapeworms. C-banding and staining with fl uorescent dyes DAPI and YOYO1 revealed a distinct banding pattern explicitly on chromosomes with centromeric bright heterochromatin bands present on all 10 chromosome pairs; no pair showed any interstitial heterochromatin. A complete course of spermatocyte meiosis and dynamics of nucleolus formation and degradation during meiotic division was described.

Semi-automatic laser beam microdissection of the Y chromosome and analysis of Y chromosome DNA in a dioecious plant, Silene latifolia

International Nuclear Information System (INIS)

Matsunaga, S.; Kawano, S.; Michimoto, T.; Higashiyama, T.; Nakao, S.; Sakai, A.; Kuroiwa, T.

1999-01-01

Silene latifolia has heteromorphic sex chromosomes, the X and Y chromosomes. The Y chromosome, which is thought to carry the male determining gene, was isolated by UV laser microdissection and amplified by degenerate oligonucleotide-primed PCR. In situ chromosome suppression of the amplified Y chromosome DNA in the presence of female genomic DNA as a competitor showed that the microdissected Y chromosome DNA did not specifically hybridize to the Y chromosome, but-hybridized to all chromosomes. This result suggests that the Y chromosome does not contain Y chromosome-enriched repetitive sequences. A repetitive sequence in the microdissected Y chromosome, RMY1, was isolated while screening repetitive sequences in the amplified Y chromosome. Part of the nucleotide sequence shared a similarity to that of X-43.1, which was isolated from microdissected X chromosomes. Since fluorescence in situ hybridization analysis with RMY1 demonstrated that RMY1 was localized at the ends of the chromosome, RMY1 may be a subtelomeric repetitive sequence. Regarding the sex chromosomes, RMY1 was detected at both ends of the X chromosome and at one end near the pseudoautosomal region of the Y chromosome. The different localization of RMY1 on the sex chromosomes provides a clue to the problem of how the sex chromosomes arose from autosomes

Chromosomal instability in women with primary ovarian insufficiency.

Science.gov (United States)

Katari, Sunita; Aarabi, Mahmoud; Kintigh, Angela; Mann, Susan; Yatsenko, Svetlana A; Sanfilippo, Joseph S; Zeleznik, Anthony J; Rajkovic, Aleksandar

2018-02-07

What is the prevalence of somatic chromosomal instability among women with idiopathic primary ovarian insufficiency (POI)? A subset of women with idiopathic POI may have functional impairment in DNA repair leading to chromosomal instability in their soma. The formation and repair of DNA double-strand breaks during meiotic recombination are fundamental processes of gametogenesis. Oocytes with compromised DNA integrity are susceptible to apoptosis which could trigger premature ovarian aging and accelerated wastage of the human follicle reserve. Genomewide association studies, as well as whole exome sequencing, have implicated multiple genes involved in DNA damage repair. However, the prevalence of defective DNA damage repair in the soma of women with POI is unknown. In total, 46 women with POI and 15 family members were evaluated for excessive mitomycin-C (MMC)-induced chromosome breakage. Healthy fertile females (n = 20) and two lymphoblastoid cell lines served as negative and as positive controls, respectively. We performed a pilot functional study utilizing MMC to assess chromosomal instability in the peripheral blood of participants. A high-resolution array comparative genomic hybridization (aCGH) was performed on 16 POI patients to identify copy number variations (CNVs) for a set of 341 targeted genes implicated in DNA repair. Array CGH revealed three POI patients (3/16, 18.8%) with pathogenic CNVs. Excessive chromosomal breakage suggestive of a constitutional deficiency in DNA repair was detected in one POI patient with the 16p12.3 duplication. In two patients with negative chromosome breakage analysis, aCGH detected a Xq28 deletion comprising the Centrin EF-hand Protein 2 (CETN2) and HAUS Augmin Like Complex Subunit 7 (HAUS7) genes essential for meiotic DNA repair, and a duplication in the 3p22.2 region comprising a part of the ATPase domain of the MutL Homolog 1 (MLH1) gene. Peripheral lymphocytes, used as a surrogate tissue to quantify induced chromosome

Chromosome survey for children of A-bomb survivors

International Nuclear Information System (INIS)

Awa, Akio

1992-01-01

To investigate chromosomes from children of A-bomb survivors, cytogenetic survey has been started in 1967 by the ABCC and completed in 1985 by the succeeding RERF. This paper is designed to overview the cytogenetic survey and to discuss the cytogenetic effects of A-bomb radiation. A cohort of 16,298 children of A-bomb survivors, which were collected from mortality survey population in 1974, was enrolled in this survey and was divided into two groups: the proximally exposed group (n=8,322, whose parents exposed to estimated doses of 0.01 Gy or more within 2,000 m from the hypocenter) and the distally exposed group (n=7,976, those exposed to 0.005 Gy or less far from 2,500 m or not in the city). Three chromosomal aberrations were identified: sex chromosome aberrations consisting mainly of XYY, XXY, and mosaic; structural abnormality of autosomes consisting mainly of translocation and inversion; and trisomy of autosomes. Overall, the incidence of chromosomal aberrations was higher in the distally exposed group (6.39%) than the proximally exposed group (5.17%). According to the type of chromosomal aberrations, the incidences of both sex chromosomes and structural abnormality of autosomes were slightly higher in the distally exposed group (0.30% and 0.34%) than the proximally exposed group (0.23% and 0.28%). Trisomy of autosomes was identified in only one child in the proximally exposed group. These findings failed to demonstrate the rationale for the cytogenetic effects of A-bomb radiation; however, cytogenetic risk of radiation has not been denied completely. (N.K.)

Integration profile and safety of an adenovirus hybrid-vector utilizing hyperactive sleeping beauty transposase for somatic integration.

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Wenli Zhang

Full Text Available We recently developed adenovirus/transposase hybrid-vectors utilizing the previously described hyperactive Sleeping Beauty (SB transposase HSB5 for somatic integration and we could show stabilized transgene expression in mice and a canine model for hemophilia B. However, the safety profile of these hybrid-vectors with respect to vector dose and genotoxicity remains to be investigated. Herein, we evaluated this hybrid-vector system in C57Bl/6 mice with escalating vector dose settings. We found that in all mice which received the hyperactive SB transposase, transgene expression levels were stabilized in a dose-dependent manner and that the highest vector dose was accompanied by fatalities in mice. To analyze potential genotoxic side-effects due to somatic integration into host chromosomes, we performed a genome-wide integration site analysis using linker-mediated PCR (LM-PCR and linear amplification-mediated PCR (LAM-PCR. Analysis of genomic DNA samples obtained from HSB5 treated female and male mice revealed a total of 1327 unique transposition events. Overall the chromosomal distribution pattern was close-to-random and we observed a random integration profile with respect to integration into gene and non-gene areas. Notably, when using the LM-PCR protocol, 27 extra-chromosomal integration events were identified, most likely caused by transposon excision and subsequent transposition into the delivered adenoviral vector genome. In total, this study provides a careful evaluation of the safety profile of adenovirus/Sleeping Beauty transposase hybrid-vectors. The obtained information will be useful when designing future preclinical studies utilizing hybrid-vectors in small and large animal models.

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

Unique mosaicism of structural chromosomal rearrangement: is chromosome 18 preferentially involved?

NARCIS (Netherlands)

Pater, J.M. de; Smeets, D.F.C.M.; Scheres, J.M.J.C.

2003-01-01

The mentally normal mother of a 4-year-old boy with del(18)(q21.3) syndrome was tested cytogenetically to study the possibility of an inherited structural rearrangement of chromosome 18. She was found to carry an unusual mosaicism involving chromosomes 18 and 21. Two unbalanced cell lines were seen

B chromosomes are associated with redistribution of genetic recombination towards lower recombination chromosomal regions in perennial ryegrass.

Science.gov (United States)

Harper, John; Phillips, Dylan; Thomas, Ann; Gasior, Dagmara; Evans, Caron; Powell, Wayne; King, Julie; King, Ian; Jenkins, Glyn; Armstead, Ian

2018-04-09

Supernumerary 'B' chromosomes are non-essential components of the genome present in a range of plant and animal species-including many grasses. Within diploid and polyploid ryegrass and fescue species, including the forage grass perennial ryegrass (Lolium perenne L.), the presence of B chromosomes has been reported as influencing both chromosome pairing and chiasma frequencies. In this study, the effects of the presence/absence of B chromosomes on genetic recombination has been investigated through generating DArT (Diversity Arrays Technology) marker genetic maps for six perennial ryegrass diploid populations, the pollen parents of which contained either two B or zero B chromosomes. Through genetic and cytological analyses of these progeny and their parents, we have identified that, while overall cytological estimates of chiasma frequencies were significantly lower in pollen mother cells with two B chromosomes as compared with zero B chromosomes, the recombination frequencies within some marker intervals were actually increased, particularly for marker intervals in lower recombination regions of chromosomes, namely pericentromeric regions. Thus, in perennial ryegrass, the presence of two B chromosomes redistributed patterns of meiotic recombination in pollen mother cells in ways which could increase the range of allelic variation available to plant breeders.

Chromosomal aneuploidies and copy number variations in posterior fossa abnormalities diagnosed by prenatal ultrasonography.

Science.gov (United States)

Lei, Ting; Feng, Jie-Ling; Xie, Ying-Jun; Xie, Hong-Ning; Zheng, Ju; Lin, Mei-Fang

2017-11-01

To explore the genetic aetiology of fetal posterior fossa abnormalities (PFAs). This study involved cases of PFAs that were identified by prenatal ultrasonographic screening and confirmed postnatally between January 2012 and January 2016. Conventional cytogenetic analyses and chromosomal microarray analysis were performed, and chromosomal aneuploidies and copy number variations (CNVs) were identified. Among 74 cases included in this study, 8 were of Blake's pouch cyst; 7, Dandy-Walker malformation; 11, vermian hypoplasia; 32, enlarged cisterna magna; and 16, cerebellar hypoplasia. The rates of nonbenign chromosomal aberrations (including chromosomal aneuploidies, pathogenic CNVs, and variants of unknown significance) were 2/8 (25.0%), 2/7 (28.5%), 8/11 (72.7%), 7/32 (21.9%), and 6/16 (37.5%), respectively. Cases were also classified as isolated PFAs (30/74), PFAs with other central nervous system (CNS) abnormalities (13/74), or PFAs with extra-CNS structural abnormalities (31/74). No fetuses with isolated PFAs or PFAs accompanied by other CNS abnormalities exhibited chromosomal aneuploidies or pathogenic CNVs. The rate of pathogenic chromosomal aberrations in the remaining fetuses was 17/31 (22.9%). The combined use of chromosomal microarray analysis and karyotype analysis might assist the prenatal diagnosis and management of PFAs, with extra-CNS structural abnormalities being detected by ultrasonography. © 2017 John Wiley & Sons, Ltd.

Biological dosimetry in radiation accidents. Dose-response curve by chromosomal aberrations analysis

International Nuclear Information System (INIS)

Hadjidekova, V.; Hristova, R.; Atanasova, P.; Popova, L.; Stainova, A.; Bulanova, M.; Georgieva, I.; Vukov, M.

2005-01-01

The aim of this paper is to obtain a dose-response relationship for chromosomal aberrations induced in human lymphocytes after in vitro irradiation. Peripheral blood samples of 7 different donors were used. The blood irradiation was done with Cs137 gamma-rays at different doses: 0.0, 0.05, 0.1, 0.25, 0.5, 0.75, 1.0, 1.5, 2.0 and 3.0 Gy. Lymphocyte cultures were established and maintain for 48 hours at 37 0 C in CO 2 incubator for chromosomal aberration analysis. The dose response relationship has been established based on dysenteric and ring chromosomes yield. The relationship can be described by the following equation: Y = 0.0274D + 0.0251 D 2 , where (Y) = dysenteric and ring chromosomes yield, (D) = radiation dose obtained. EXCEL software was established for calculation of the received dose by using this equation, as a whole body equivalent dose acute irradiation

HIM-8 binds to the X chromosome pairing center and mediates chromosome-specific meiotic synapsis.

Science.gov (United States)

Phillips, Carolyn M; Wong, Chihunt; Bhalla, Needhi; Carlton, Peter M; Weiser, Pinky; Meneely, Philip M; Dernburg, Abby F

2005-12-16

The him-8 gene is essential for proper meiotic segregation of the X chromosomes in C. elegans. Here we show that loss of him-8 function causes profound X chromosome-specific defects in homolog pairing and synapsis. him-8 encodes a C2H2 zinc-finger protein that is expressed during meiosis and concentrates at a site on the X chromosome known as the meiotic pairing center (PC). A role for HIM-8 in PC function is supported by genetic interactions between PC lesions and him-8 mutations. HIM-8 bound chromosome sites associate with the nuclear envelope (NE) throughout meiotic prophase. Surprisingly, a point mutation in him-8 that retains both chromosome binding and NE localization fails to stabilize pairing or promote synapsis. These observations indicate that stabilization of homolog pairing is an active process in which the tethering of chromosome sites to the NE may be necessary but is not sufficient.

HIM-8 binds to the X chromosome pairing center and mediates chromosome-specific meiotic synapsis

International Nuclear Information System (INIS)

Phillips, Carolyn M.; Wong, Chihunt; Bhalla, Needhi; Carlton, Peter M.; Weiser, Pinky; Meneely, Philip M.; Dernburg, Abby F.

2005-01-01

The him-8 gene is essential for proper meiotic segregation of the X chromosomes in C. elegans. Here we show that loss of him-8 function causes profound X-chromosome-specific defects in homolog pairing and synapsis.him-8 encodes a C2H2 zinc finger protein that is expressed during meiosis and concentrates at a site on the X chromosome known as themeiotic Pairing Center (PC). A role for HIM-8 in PC function is supported by genetic interactions between PC lesions and him-8 mutations. HIM-8-bound chromosome sites associate with the nuclear envelope (NE)throughout meiotic prophase. Surprisingly, a point mutation in him-8 that retains both chromosome binding and NE localization fails to stabilize pairing or promote synapsis. These observations indicate that stabilization of homolog pairing is an active process in which the tethering of chromosome sites to the NE may be necessary but is not sufficient

Statistics for X-chromosome associations.

Science.gov (United States)

Özbek, Umut; Lin, Hui-Min; Lin, Yan; Weeks, Daniel E; Chen, Wei; Shaffer, John R; Purcell, Shaun M; Feingold, Eleanor

2018-06-13

In a genome-wide association study (GWAS), association between genotype and phenotype at autosomal loci is generally tested by regression models. However, X-chromosome data are often excluded from published analyses of autosomes because of the difference between males and females in number of X chromosomes. Failure to analyze X-chromosome data at all is obviously less than ideal, and can lead to missed discoveries. Even when X-chromosome data are included, they are often analyzed with suboptimal statistics. Several mathematically sensible statistics for X-chromosome association have been proposed. The optimality of these statistics, however, is based on very specific simple genetic models. In addition, while previous simulation studies of these statistics have been informative, they have focused on single-marker tests and have not considered the types of error that occur even under the null hypothesis when the entire X chromosome is scanned. In this study, we comprehensively tested several X-chromosome association statistics using simulation studies that include the entire chromosome. We also considered a wide range of trait models for sex differences and phenotypic effects of X inactivation. We found that models that do not incorporate a sex effect can have large type I error in some cases. We also found that many of the best statistics perform well even when there are modest deviations, such as trait variance differences between the sexes or small sex differences in allele frequencies, from assumptions. © 2018 WILEY PERIODICALS, INC.

Chromosomal aberrations in Cynomolgus peripheral lymphocytes during and after fractionated whole-body γ-irradiation

International Nuclear Information System (INIS)

Guedeney, G.; Malarbet, J.L.; Doloy, M.T.

1989-01-01

Cynomolgus monkeys (Macaca fascicularis) were exposed to fractionated whole-body γ-irradiation at high and low dose rates for 4 or 5 weeks. The time-dependence of chromosomal aberrations was studied in relation to the number of lymphocytes during irradiation and after exposure for periods of up to about 600 days for chromosomal aberrations and 200 days for lymphocyte counts. Additivity of the daily effects on the number of chromosomal aberrations was observed during the exposures. Immediately after the end of the exposures the number of chromosomal aberrations decreased to reach low values. The disappearance of chromosomal aberrations seemed to be related to recovery of the lymphocyte counts. The data presented here emphasize the different kinetic patterns of chromosomal aberrations after fractionated and acute irradiation. (author)

Drosophila polytene chromosome bands formed by gene introns.

Science.gov (United States)

Zhimulev, I F; Boldyreva, L V; Demakova, O V; Poholkova, G V; Khoroshko, V A; Zykova, T Yu; Lavrov, S A; Belyaeva, E S

2016-01-01

Genetic organization of bands and interbands in polytene chromosomes has long remained a puzzle for geneticists. It has been recently demonstrated that interbands typically correspond to the 5'-ends of house-keeping genes, whereas adjacent loose bands tend to be composed of coding sequences of the genes. In the present work, we made one important step further and mapped two large introns of ubiquitously active genes on the polytene chromosome map. We show that alternative promoter regions of these genes map to interbands, whereas introns and coding sequences found between those promoters correspond to loose grey bands. Thus, a gene having its long intron "sandwiched" between to alternative promoters and a common coding sequence may occupy two interbands and one band in the context of polytene chromosomes. Loose, partially decompacted bands appear to host large introns.

Partial trisomy 5q resulting from chromosome 7 insertion: An expansion of the phenotype

Energy Technology Data Exchange (ETDEWEB)

Fries, M.H.; Reilly, P.A.; Williams, T.C. [Keesler Medical Center, MS (United States)] [and others

1994-09-01

Partial trisomy 5q has been categorized into three separate phenotypes; however, a distinctive phenotype has not been described for duplications spanning 5q23-q35. We report a case of partial trisomy 5q for this region as a result of a ins(7,5)(q31.3;q23.2q35.1)mat. The liveborn male infant was delivered by emergency cesarean section at 37 weeks after a pregnancy notable for oligohydramnios, with birth weight 1792 g (<3%). Postnatal course was marked by psychomotor delay, failure to thrive, and biopsy demonstrated neonatal giant cell hepatitis with a paucity of intrahepatic bile ducts. His appearance was remarkable for lack of subcutaneous fat, midline displaced hair whorl, bitemporal narrowing with frontal bossing, wide anterior fontanel, widow`s peak, protuberant eyes with periorbital and lid edema, short flat nasal bridge with broad flattened nasal tip, long smooth philtrum, wide mouth with thin lips, wide gingival ridges, micrognathia, posteriorly rotated low-set ears, hepatomegaly, flexion contractions of elbows, and generalized hypertonicity. Urine organic acids, oligosaccharide/mucopolysaccharide screen, and plasma amino acids were negative. GTG-banding on prometaphase chromosomes showed an unbalanced translocation involving chr. 7. This was identified as an insertion of chr. 5 (q23.2q35.1) into distal 7q after FISH using chr. 5 and chr. 7 painting probes. The infant`s mother carries the balanced insertional rearrangement: 46,XX,dir ins(7,5)(q31.3;q23.2q35.1). This phenotype overlaps that of previously described duplications with the addition of giant cell hepatitis, coarsened facial features, gingival thickening, and flexion contractures, suggestive of a yet undiagnosed storage disorder.

Bacterial Artificial Chromosome Libraries of Pulse Crops: Characteristics and Applications

OpenAIRE

Kangfu Yu

2012-01-01

Pulse crops are considered minor on a global scale despite their nutritional value for human consumption. Therefore, they are relatively less extensively studied in comparison with the major crops. The need to improve pulse crop production and quality will increase with the increasing global demand for food security and people's awareness of nutritious food. The improvement of pulse crops will require fully utilizing all their genetic resources. Bacterial artificial chromosome (BAC) libraries...

Chromosome Connections: Compelling Clues to Common Ancestry

Science.gov (United States)

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…

Robot system for preparing lymphocyte chromosome

International Nuclear Information System (INIS)

Hayata, Isamu; Furukawa, Akira; Yamamoto, Mikio; Sato, Koki; Tabuchi, Hiroyoshi; Okabe, Nobuo.

1992-01-01

Towards the automatization of the scoring of chromosome aberrations in radiation dosimetry with the emphasis on the improvement of biological preparations, the conventional culture and harvesting method was modified. Based on this modified method, a culture and harvest robotic system (CHROSY) for preparing lymphocyte chromosome was developed. The targeted points of the modification are as in the preparing lymphocyte chromosome was developed. The targeted points of the modification are as in the following. 1) Starting culture with purified lymphocytes in a fixed cell number. 2) Avoiding the loss of cells in changing the liquids following centrifugalization. 3) Keeping the quantity of the liquids to be applied to the treatments of cells fixed. 4) Building a system even a beginner can handle. System features are as follows. 1) Operation system: Handling robot having 5 degrees of freedom; a rotator incubator with an automatic sliding door; units for setting and removing pipette tips; a centrifuge equipped with a position adjuster and an automatic sliding door; two aluminium block baths; two nozzles as pipettes and aspirators connected to air pumps; a capping unit with a nozzle for CO 2 gas; a compressor; and an air manipulated syringe. 2) Control system; NEC PC-9801RX21 with CRT; and program written in Basic and Assembly languages on MS-DOS. It took this system 2 hours and 25 minutes to harvest 2 cultures. A fairly good chromosome slide was made from the sample harvested by CHROSY automatically. (author)

Utilizing a TLR5-Adjuvanted Cytomegalovirus as a Lentiviral Vaccine in the Nonhuman Primate Model for AIDS.

Directory of Open Access Journals (Sweden)

Jesse D Deere

Full Text Available Despite tremendous progress in our understanding of human immunodeficiency virus (HIV natural history and advances in HIV treatment, there is neither an approved vaccine nor a cure for infection. Here, we describe the development and characterization of a novel replicating vaccine vector utilizing Cytomegalovirus (CMV and a TLR5 adjuvant. After partial truncation of the central, immunodominant hypervariable domain, flagellin (fliC from Salmonella was cloned downstream of a codon optimized gag gene from simian immunodeficiency virus (SIV and transiently expressed in telomerized rhesus fibroblast (TeloRF cells in culture. Lysates generated from these transfected cells induced the tumor necrosis factor alpha (TNF-α, in a mouse macrophage cell line, in a TLR5-dependent manner. The Gag/FliC expression construct was cloned into a bacterial artificial chromosome encoding the rhesus CMV (RhCMV genome, and infectious RhCMV was generated following transfection of TeloRF cells. This virus stably expressed an SIV Gag/FliC fusion protein through four serial passages. Lysates generated from infected cells induced TNF-α in a TLR5-dependent manner. Western blot analysis of infected cell lysates verified expression of a Gag/FliC fusion protein using a SIV p27 capsid monoclonal antibody. Lastly, rhesus macaques inoculated with this novel RhCMV virus demonstrated increased inflammatory responses at the site of inoculation seven days post-infection when compared to the parental RhCMV. These results demonstrate that an artificially constructed replicating RhCMV expressing an SIV Gag/FliC fusion protein is capable of activating TLR5 in a macrophage cell line in vitro and induction of an altered inflammatory response in vivo. Ongoing animals studies are aimed at determining vaccine efficacy, including subsequent challenge with pathogenic SIV.

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).

Molecular diagnostic of the philadelphia chromosome

International Nuclear Information System (INIS)

Campos Rudin, M.; Cuenca Berger, P.; Gutierrez Espeleta, G.; Jimenez Cruz, G.; Montero Umana, C.; Vazquez Castillo, L.; Ramon Ortiz, M.

1998-01-01

The importance that has to confirm the presence or absence of the chromosome Philadelphia in the diagnostic and follow up of the patient affected with chronic myeloid leukemia and other leukemia. It is considered necessary to implement the molecular diagnostic in Costa Rica. They studied 32 patient affected by Chronic Myeloid Leukemia, 7 by other Myeloproliferative Chronic Disorders and 2 by Myelodysplastic Syndrome. It utilized the sound Trans probe-1 (Oncogene Science, Inc), which was marked with radioactivity ( 32 P) or chemiluminescence (digoxigenin). Of the 32 cases affected by L mc, in 28 it was possible to carry out the molecular analysis detecting the characteristic translocation of the chromosome Philadelphia among the Mbcr/c-ABL genes in 21 (75%) of the patients, in 7 (25%) the rearrangement was not found. In seven of the nine affected by other sufferings it was possible to obtain results, 3 that turned out to be positive for the rearrangement among Mbcr/c-ABL and 4 normal. In all the cases, they obtained results marking the sound with radioactivity. However, they tested the marks with digoxigenin in seven of the patients, as an methodological alternative for the laboratories that lacks the requirements to work with radiation. The results obtained were identical. (S. Grainger) [es

Karyotype evolution in Rhinolophus bats (Rhinolophidae, Chiroptera) illuminated by cross-species chromosome painting and G-banding comparison.

Science.gov (United States)

Mao, Xiuguang; Nie, Wenhui; Wang, Jinhuan; Su, Weiting; Ao, Lei; Feng, Qing; Wang, Yingxiang; Volleth, Marianne; Yang, Fengtang

2007-01-01

Rhinolophus (Rhinolophidae) is the second most speciose genus in Chiroptera and has extensively diversified diploid chromosome numbers (from 2n = 28 to 62). In spite of many attempts to explore the karyotypic evolution of this genus, most studies have been based on conventional Giemsa staining rather than G-banding. Here we have made a whole set of chromosome-specific painting probes from flow-sorted chromosomes of Aselliscus stoliczkanus (Hipposideridae). These probes have been utilized to establish the first genome-wide homology maps among six Rhinolophus species with four different diploid chromosome numbers (2n = 36, 44, 58, and 62) and three species from other families: Rousettus leschenaulti (2n = 36, Pteropodidae), Hipposideros larvatus (2n = 32, Hipposideridae), and Myotis altarium (2n = 44, Vespertilionidae) by fluorescence in situ hybridization. To facilitate integration with published maps, human paints were also hybridized to A. stoliczkanus chromosomes. Our painting results substantiate the wide occurrence of whole-chromosome arm conservation in Rhinolophus bats and suggest that Robertsonian translocations of different combinations account for their karyotype differences. Parsimony analysis using chromosomal characters has provided some new insights into the Rhinolophus ancestral karyotype and phylogenetic relationships among these Rhinolophus species so far studied. In addition to Robertsonian translocations, our results suggest that whole-arm (reciprocal) translocations involving multiple non-homologous chromosomes as well could have been involved in the karyotypic evolution within Rhinolophus, in particular those bats with low and medium diploid numbers.

Meiotic inheritance of a fungal supernumerary chromosome and its effect on sexual fertility in Nectria haematococca.

Science.gov (United States)

Garmaroodi, Hamid S; Taga, Masatoki

2015-10-01

PDA1-conditionally dispensable chromosome (CDC) of Nectria haematococca MP VI has long served as a model of supernumerary chromosomes in plant pathogenic fungi because of pathogenicity-related genes located on it. In our previous study, we showed the dosage effects of PDA1-CDC on pathogenicity and homoserine utilization by exploiting tagged PDA1-CDC with a marker gene. CDC content of mating partners and progenies analyzed by PCR, PFGE combined with Southern analysis and chromosome painting via FISH. In this study, we analyzed mode of meiotic inheritance of PDA1-CDC in several mating patterns with regard to CDC content and found a correlation between CDC content of parental strains with fertility of crosses. The results showed non-Mendelian inheritance of this chromosome followed by duplication or loss of the CDC in haploid genome through meiosis that probably were due to premature centromere division, not by nondisjunction as reported for the supernumerary chromosomes in other species. Correlation of CDC with fertility is the first time to be examined in fungi in this study. Copyright © 2015 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

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.

Comparative physical mapping between wheat chromosome arm 2BL and rice chromosome 4.

Science.gov (United States)

Lee, Tong Geon; Lee, Yong Jin; Kim, Dae Yeon; Seo, Yong Weon

2010-12-01

Physical maps of chromosomes provide a framework for organizing and integrating diverse genetic information. DNA microarrays are a valuable technique for physical mapping and can also be used to facilitate the discovery of single feature polymorphisms (SFPs). Wheat chromosome arm 2BL was physically mapped using a Wheat Genome Array onto near-isogenic lines (NILs) with the aid of wheat-rice synteny and mapped wheat EST information. Using high variance probe set (HVP) analysis, 314 HVPs constituting genes present on 2BL were identified. The 314 HVPs were grouped into 3 categories: HVPs that match only rice chromosome 4 (298 HVPs), those that match only wheat ESTs mapped on 2BL (1), and those that match both rice chromosome 4 and wheat ESTs mapped on 2BL (15). All HVPs were converted into gene sets, which represented either unique rice gene models or mapped wheat ESTs that matched identified HVPs. Comparative physical maps were constructed for 16 wheat gene sets and 271 rice gene sets. Of the 271 rice gene sets, 257 were mapped to the 18-35 Mb regions on rice chromosome 4. Based on HVP analysis and sequence similarity between the gene models in the rice chromosomes and mapped wheat ESTs, the outermost rice gene model that limits the translocation breakpoint to orthologous regions was identified.

Requirement of mitoses for the reversal of X-inactivation in cell hybrids between murine embryonal carcinoma cells and normal female thymocytes

International Nuclear Information System (INIS)

Takagi, N.

1988-01-01

By means of a 5-bromodeoxyuridine (BrdU) incorporation and acridine orange fluorescence staining method the authors studied reactivation of the inactivated X chromosome (X i ) in newly formed cell hybrids between the near-diploid HPRT-deficient OTF9-63 murine embryonal carcinoma cell (ECC) with an XO sex chromosome constitution and the normal female mouse thymocyte. Synchronization of the late replicating S chromosome in such hybrid cells, indicative of reactivation, was found for the first time on Day 3, and the frequency of reactivation was attained 90% on Day 5. Inhibition of cell cycle progression either by methylglyoxal bis(guanylhydrazone) dihydrochloride, an inhibitor of polyamine metabolism, or by isoleucine-deficient medium after cell fusion delayed reactivation of the X i , which implied that the number of cell division cycles traversed by individual cells rather than the length of time after cell fusion is critical for the reactivation. Double-labeling experiments using [ 3 H]thymidine and BrdU indicated that hybrid cells had undergone three or four mitoses before reactivation of the X i . Most probably reactivation of the X i is consequent to reversion of the thymocyte genome to an undifferentiated state under the influence of OTF9 genome. DNA demethylation or dilution of X i -specific factors by mitoses may be involved in this process

Requirement of mitoses for the reversal of X-inactivation in cell hybrids between murine embryonal carcinoma cells and normal female thymocytes

Energy Technology Data Exchange (ETDEWEB)

Takagi, N. (Hokkaido Univ., Sapporo (Japan))

1988-04-01

By means of a 5-bromodeoxyuridine (BrdU) incorporation and acridine orange fluorescence staining method the authors studied reactivation of the inactivated X chromosome (X{sub i}) in newly formed cell hybrids between the near-diploid HPRT-deficient OTF9-63 murine embryonal carcinoma cell (ECC) with an XO sex chromosome constitution and the normal female mouse thymocyte. Synchronization of the late replicating S chromosome in such hybrid cells, indicative of reactivation, was found for the first time on Day 3, and the frequency of reactivation was attained 90% on Day 5. Inhibition of cell cycle progression either by methylglyoxal bis(guanylhydrazone) dihydrochloride, an inhibitor of polyamine metabolism, or by isoleucine-deficient medium after cell fusion delayed reactivation of the X{sub i}, which implied that the number of cell division cycles traversed by individual cells rather than the length of time after cell fusion is critical for the reactivation. Double-labeling experiments using ({sup 3}H)thymidine and BrdU indicated that hybrid cells had undergone three or four mitoses before reactivation of the X{sub i}. Most probably reactivation of the X{sub i} is consequent to reversion of the thymocyte genome to an undifferentiated state under the influence of OTF9 genome. DNA demethylation or dilution of X{sub i}-specific factors by mitoses may be involved in this process.

A Rare De novo Complex Chromosomal Rearrangement (CCR) Involving Four Chromosomes in An Oligo-asthenosperm Infertile Man.

Science.gov (United States)

Asia, Saba; Vaziri Nasab, Hamed; Sabbaghian, Marjan; Kalantari, Hamid; Zari Moradi, Shabnam; Gourabi, Hamid; Mohseni Meybodi, Anahita

2014-01-01

Complex chromosomal rearrangements (CCRs) are rare events involving more than two chromosomes and over two breakpoints. They are usually associated with infertility or sub fertility in male carriers. Here we report a novel case of a CCR in a 30-year-old oligoasthenosperm man with a history of varicocelectomy, normal testes size and normal endocrinology profile referred for chromosome analysis to the Genetics unit of Royan Reproductive Biomedicine Research Center. Chromosomal analysis was performed using peripheral blood lymphocyte cultures and analyzed by GTG banding. Additional tests such as C-banding and multicolor fluorescence in situ hybridization (FISH) procedure for each of the involved chromosomes were performed to determine the patterns of the segregations. Y chromosome microdeletions in the azoospermia factor (AZF) region were analyzed with multiplex polymerase chain reaction. To identify the history and origin of this CCR, all the family members were analyzed. No micro deletion in Y chromosome was detected. The same de novo reciprocal exchange was also found in his monozygous twin brother. The other siblings and parents were normal. CCRs are associated with male infertility as a result of spermatogenic disruption due to complex meiotic configurations and the production of chromosomally abnormal sperms. These chromosomal rearrangements might have an influence on decreasing the number of sperms.

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.

Long-term cytogenetic effects of antineoplastic treatment in relation to secondary leukemia

International Nuclear Information System (INIS)

Genuardi, M.; Zollino, M.; Serra, A.; Leone, G.; Mancini, R.; Mango, G.; Neri, G.

1988-01-01

Chromosome translocations are consistently present in leukemias and lymphomas and are likely to represent primary events in the development of these neoplasias. A study of conditions that predispose to leukemia could shed some light on the origin of these translocations and therefore help in clarifying their exact role in the process of neoplastic transformation. Based on this assumption, we studied a group of individuals treated with radiochemotherapy for previous lymphoma and who were at increased risk of developing a secondary leukemia. The group comprised 14 Hodgkin's disease patients, 11 non-Hodgkin's lymphoma patients, and 13 controls. The patients were in remission and had been off therapy for at least 6 months. Chromosomes were studied from phytohemagglutinin (PHA)-stimulated peripheral lymphocytes and from bone marrow cells by the direct method and after short-term cultures (72 hours). The latter were also exposed to 5-bromodeoxyuridine (BrdU). Metaphases were scored for chromosome breaks, gaps, and other rearrangements. The percentage of gaps and breaks was significantly higher in patients than in controls. The difference was induced by BrdU and was apparent in bone marrow cells, but not in peripheral lymphocytes. We conclude that individuals exposed to the action of mutagenic agents (radiochemotherapy) have an increased chromosome instability that could be related to their increased risk of developing a secondary leukemia

Chromosome damage in Chinese hamster cells produced by 125I-UdR at the site of its incorporation

International Nuclear Information System (INIS)

Hughes, W.L.; Weinblatt, A.C.; Prensky, W.

1978-01-01

Metaphase chromosomal aberrations were produced by 125 I-labeled iododeoxyuridine ( 125 I-UdR) incorporated into Chinese hamster Don cells at the end of the S-period of the cell cycle. Chromosome damage and the number of autoradiographic silver grains were recorded for whole cells, for chromosome pairs 4 and 5 and for the X and the Y chromosomes. The X and the Y chromosomes, which label late in S, were at least twice as heavily labeled as chromosome pairs 4 and 5 - two readily recognizable autosomes of similar size. The incidence of chromosome damage was at least six times that which would have been expected from equivalent doses of X-rays and the incidence of damage was directly related to the number of silver grains over each chromosome. It is estimated that it takes four to ten disintegrations to produce a visible chromosome aberration. The finding that chromosome damage is localized at the site of the 125 I decay is most readily explained by the high flux of low energy Auger electrons occurring at the site of the decay of the incorporated 125 I atom. (Auth.)

Mapping of the serotonin 5-HT{sub 1D{alpha}} autoreceptor gene (HTR1D) on chromosome 1 using a silent polymorphism in the coding region

Energy Technology Data Exchange (ETDEWEB)

Ozaki, N.; Lappalainen, J.; Linnoila, M. [National Institute on Alcohol Abuse and Alcoholism, Rockville, MD (United States)] [and others

1995-04-24

Serotonin (5-HT){sub ID} receptors are 5-HT release-regulating autoreceptors in the human brain. Abnormalities in brain 5-HT function have been hypothesized in the pathophysiology of various psychiatric disorders, including obsessive-compulsive disorder, autism, mood disorders, eating disorders, impulsive violent behavior, and alcoholism. Thus, mutations occurring in 5-HT autoreceptors may cause or increase the vulnerability to any of these conditions. 5-HT{sub 1D{alpha}} and 5-HT{sub 1D{Beta}} subtypes have been previously localized to chromosomes 1p36.3-p34.3 and 6q13, respectively, using rodent-human hybrids and in situ localization. In this communication, we report the detection of a 5-HT{sub 1D{alpha}} receptor gene polymorphism by single strand conformation polymorphism (SSCP) analysis of the coding sequence. The polymorphism was used for fine scale linkage mapping of 5-HT{sub 1D{alpha}} on chromosome 1. This polymorphism should also be useful for linkage studies in populations and in families. Our analysis also demonstrates that functionally significant coding sequence variants of the 5-HT{sub 1D{alpha}} are probably not abundant either among alcoholics or in the general population. 14 refs., 1 fig., 1 tab.

Localization of the panhypopituitary dwarf mutation (df) on mouse chromosome 11 in an intersubspecific backcross.

Science.gov (United States)

Buckwalter, M S; Katz, R W; Camper, S A

1991-07-01

Ames dwarf (df) is an autosomal recessive mutation characterized by severe dwarfism and infertility. This mutation provides a mouse model for panhypopituitarism. The dwarf phenotype results from failure in the differentiation of the cells which produce growth hormone, prolactin, and thyroid stimulating hormone. Using the backcross (DF/B-df/df X CASA/Rk) X DF/B-df/df, we confirmed the assignment of df to mouse chromosome 11 and demonstrated recombination between df and the growth hormone gene. This backcross is an invaluable resource for screening candidate genes for the df mutation. The df locus maps to less than 1 cM distal to Pad-1 (0.85 +/- 0.85 cM). Two new genes localized on mouse chromosome 11, Rpo2-1, and Edp-1, map to a region of conserved synteny with human chromosome 17. The localization of the alpha 1 adrenergic receptor, Adra-1, extends a known region of synteny conservation between mouse chromosome 11 and human chromosome 5, and suggests that a human counterpart to df would map to human chromosome 5.

HPV type-related chromosomal profiles in high-grade cervical intraepithelial neoplasia

Directory of Open Access Journals (Sweden)

Bierkens Mariska

2012-01-01

Full Text Available Abstract Background The development of cervical cancer and its high-grade precursor lesions (Cervical Intraepithelial Neoplasia grade 2/3 [CIN2/3] result from a persistent infection with high-risk human papillomavirus (hrHPV types and the accumulation of (epigenetic host cell aberrations. Epidemiological studies have demonstrated variable CIN2/3 and cancer risks between different hrHPV types. Recent genomic profiling studies revealed substantial heterogeneity in the chromosomal aberrations detected in morphologically indistinguishable CIN2/3 suggestive of varying cancer risk. The current study aimed to investigate whether CIN2/3 with different hrHPV types vary with respect to their chromosomal profiles, both in terms of the number of aberrations and chromosomal loci affected. Methods Chromosomal profiles were determined of 43 p16INK4a-immunopositive CIN2/3 of women with long-term hrHPV infection (≥ 5 years. Sixteen lesions harboured HPV16, 3 HPV18, 14 HPV31, 1 HPV33, 4 HPV45, 1 HPV51, 2 HPV52 and 2 HPV58. Results Unsupervised hierarchical clustering analysis of the chromosomal profiles revealed two major clusters, characterised by either few or multiple chromosomal aberrations, respectively. A majority of 87.5% of lesions with HPV16 were in the cluster with relatively few aberrations, whereas no such unbalanced distribution was seen for lesions harbouring other hrHPV types. Analysis of the two most prevalent types (HPV16 and HPV31 in this data set revealed a three-fold increase in the number of losses in lesions with HPV31 compared to HPV16-positive lesions. In particular, losses at chromosomes 2q, 4p, 4q, 6p, 6q, 8q & 17p and gain at 1p & 1q were significantly more frequent in HPV31-positive lesions (FDR Conclusions Chromosomal aberrations in CIN2/3 are at least in part related to the hrHPV type present. The relatively low number of chromosomal aberrations observed in HPV16-positive CIN2/3 suggests that the development of these lesions is

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

Label Free Chromosome Translocation Detection with Silicon nanowires

DEFF Research Database (Denmark)

Kwasny, Dorota; Andersen, Karsten Brandt; Frøhling, Kasper Bayer

HROMOSOME translocation, which is a rearrangement of arms between two chromosomes, is a major group of chromosome abnormalities leading to cancer. As a result, two derivative chromosomes with sequences coming from both chromosomes are formed. The current translocation detection method is a Fluore......HROMOSOME translocation, which is a rearrangement of arms between two chromosomes, is a major group of chromosome abnormalities leading to cancer. As a result, two derivative chromosomes with sequences coming from both chromosomes are formed. The current translocation detection method...

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...

Female chromosome X mosaicism is age-related and preferentially affects the inactivated X chromosome

Science.gov (United States)

Machiela, Mitchell J.; Zhou, Weiyin; Karlins, Eric; Sampson, Joshua N.; Freedman, Neal D.; Yang, Qi; Hicks, Belynda; Dagnall, Casey; Hautman, Christopher; Jacobs, Kevin B.; Abnet, Christian C.; Aldrich, Melinda C.; Amos, Christopher; Amundadottir, Laufey T.; Arslan, Alan A.; Beane-Freeman, Laura E.; Berndt, Sonja I.; Black, Amanda; Blot, William J.; Bock, Cathryn H.; Bracci, Paige M.; Brinton, Louise A.; Bueno-de-Mesquita, H Bas; Burdett, Laurie; Buring, Julie E.; Butler, Mary A.; Canzian, Federico; Carreón, Tania; Chaffee, Kari G.; Chang, I-Shou; Chatterjee, Nilanjan; Chen, Chu; Chen, Constance; Chen, Kexin; Chung, Charles C.; Cook, Linda S.; Crous Bou, Marta; Cullen, Michael; Davis, Faith G.; De Vivo, Immaculata; Ding, Ti; Doherty, Jennifer; Duell, Eric J.; Epstein, Caroline G.; Fan, Jin-Hu; Figueroa, Jonine D.; Fraumeni, Joseph F.; Friedenreich, Christine M.; Fuchs, Charles S.; Gallinger, Steven; Gao, Yu-Tang; Gapstur, Susan M.; Garcia-Closas, Montserrat; Gaudet, Mia M.; Gaziano, J. Michael; Giles, Graham G.; Gillanders, Elizabeth M.; Giovannucci, Edward L.; Goldin, Lynn; Goldstein, Alisa M.; Haiman, Christopher A.; Hallmans, Goran; Hankinson, Susan E.; Harris, Curtis C.; Henriksson, Roger; Holly, Elizabeth A.; Hong, Yun-Chul; Hoover, Robert N.; Hsiung, Chao A.; Hu, Nan; Hu, Wei; Hunter, David J.; Hutchinson, Amy; Jenab, Mazda; Johansen, Christoffer; Khaw, Kay-Tee; Kim, Hee Nam; Kim, Yeul Hong; Kim, Young Tae; Klein, Alison P.; Klein, Robert; Koh, Woon-Puay; Kolonel, Laurence N.; Kooperberg, Charles; Kraft, Peter; Krogh, Vittorio; Kurtz, Robert C.; LaCroix, Andrea; Lan, Qing; Landi, Maria Teresa; Marchand, Loic Le; Li, Donghui; Liang, Xiaolin; Liao, Linda M.; Lin, Dongxin; Liu, Jianjun; Lissowska, Jolanta; Lu, Lingeng; Magliocco, Anthony M.; Malats, Nuria; Matsuo, Keitaro; McNeill, Lorna H.; McWilliams, Robert R.; Melin, Beatrice S.; Mirabello, Lisa; Moore, Lee; Olson, Sara H.; Orlow, Irene; Park, Jae Yong; Patiño-Garcia, Ana; Peplonska, Beata; Peters, Ulrike; Petersen, Gloria M.; Pooler, Loreall; Prescott, Jennifer; Prokunina-Olsson, Ludmila; Purdue, Mark P.; Qiao, You-Lin; Rajaraman, Preetha; Real, Francisco X.; Riboli, Elio; Risch, Harvey A.; Rodriguez-Santiago, Benjamin; Ruder, Avima M.; Savage, Sharon A.; Schumacher, Fredrick; Schwartz, Ann G.; Schwartz, Kendra L.; Seow, Adeline; Wendy Setiawan, Veronica; Severi, Gianluca; Shen, Hongbing; Sheng, Xin; Shin, Min-Ho; Shu, Xiao-Ou; Silverman, Debra T.; Spitz, Margaret R.; Stevens, Victoria L.; Stolzenberg-Solomon, Rachael; Stram, Daniel; Tang, Ze-Zhong; Taylor, Philip R.; Teras, Lauren R.; Tobias, Geoffrey S.; Van Den Berg, David; Visvanathan, Kala; Wacholder, Sholom; Wang, Jiu-Cun; Wang, Zhaoming; Wentzensen, Nicolas; Wheeler, William; White, Emily; Wiencke, John K.; Wolpin, Brian M.; Wong, Maria Pik; Wu, Chen; Wu, Tangchun; Wu, Xifeng; Wu, Yi-Long; Wunder, Jay S.; Xia, Lucy; Yang, Hannah P.; Yang, Pan-Chyr; Yu, Kai; Zanetti, Krista A.; Zeleniuch-Jacquotte, Anne; Zheng, Wei; Zhou, Baosen; Ziegler, Regina G.; Perez-Jurado, Luis A.; Caporaso, Neil E.; Rothman, Nathaniel; Tucker, Margaret; Dean, Michael C.; Yeager, Meredith; Chanock, Stephen J.

2016-01-01

To investigate large structural clonal mosaicism of chromosome X, we analysed the SNP microarray intensity data of 38,303 women from cancer genome-wide association studies (20,878 cases and 17,425 controls) and detected 124 mosaic X events >2 Mb in 97 (0.25%) women. Here we show rates for X-chromosome mosaicism are four times higher than mean autosomal rates; X mosaic events more often include the entire chromosome and participants with X events more likely harbour autosomal mosaic events. X mosaicism frequency increases with age (0.11% in 50-year olds; 0.45% in 75-year olds), as reported for Y and autosomes. Methylation array analyses of 33 women with X mosaicism indicate events preferentially involve the inactive X chromosome. Our results provide further evidence that the sex chromosomes undergo mosaic events more frequently than autosomes, which could have implications for understanding the underlying mechanisms of mosaic events and their possible contribution to risk for chronic diseases. PMID:27291797