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  1. Image cytometry: nuclear and chromosomal DNA quantification.

    Science.gov (United States)

    Carvalho, Carlos Roberto; Clarindo, Wellington Ronildo; Abreu, Isabella Santiago

    2011-01-01

    Image cytometry (ICM) associates microscopy, digital image and software technologies, and has been particularly useful in spatial and densitometric cytological analyses, such as DNA ploidy and DNA content measurements. Basically, ICM integrates methodologies of optical microscopy calibration, standard density filters, digital CCD camera, and image analysis softwares for quantitative applications. Apart from all system calibration and setup, cytological protocols must provide good slide preparations for efficient and reliable ICM analysis. In this chapter, procedures for ICM applications employed in our laboratory are described. Protocols shown here for human DNA ploidy determination and quantification of nuclear and chromosomal DNA content in plants could be used as described, or adapted for other studies.

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

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    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

  3. Nuclear Envelope-Associated Chromosome Dynamics during Meiotic Prophase I

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    Xinhua Zeng

    2018-01-01

    Full Text Available Chromosome dynamics during meiotic prophase I are associated with a series of major events such as chromosomal reorganization and condensation, pairing/synapsis and recombination of the homologs, and chromosome movements at the nuclear envelope (NE. The NE is the barrier separating the nucleus from the cytoplasm and thus plays a central role in NE-associated chromosomal movements during meiosis. Previous studies have shown in various species that NE-linked chromosome dynamics are actually driven by the cytoskeleton. The linker of nucleoskeleton and cytoskeleton (LINC complexes are important constituents of the NE that facilitate in the transfer of cytoskeletal forces across the NE to individual chromosomes. The LINCs consist of the inner and outer NE proteins Sad1/UNC-84 (SUN, and Klarsicht/Anc-1/Syne (KASH domain proteins. Meiosis-specific adaptations of the LINC components and unique modifications of the NE are required during chromosomal movements. Nonetheless, the actual role of the NE in chromosomic dynamic movements in plants remains elusive. This review summarizes the findings of recent studies on meiosis-specific constituents and modifications of the NE and corresponding nucleoplasmic/cytoplasmic adaptors being involved in NE-associated movement of meiotic chromosomes, as well as describes the potential molecular network of transferring cytoplasm-derived forces into meiotic chromosomes in model organisms. It helps to gain a better understanding of the NE-associated meiotic chromosomal movements in plants.

  4. Changes in Nuclear Orientation Patterns of Chromosome 11 during Mouse Plasmacytoma Development

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    Ann-Kristin Schmälter

    2015-10-01

    Full Text Available Studying changes in nuclear architecture is a unique approach toward the understanding of nuclear remodeling during tumor development. One aspect of nuclear architecture is the orientation of chromosomes in the three-dimensional nuclear space. We studied mouse chromosome 11 in lymphocytes of [T38HxBALB/c]N mice with a reciprocal translocation between chromosome X and 11 (T38HT(X;11 exhibiting a long chromosome T(11;X and a short chromosome T(X;11 and in fast-onset plasmacytomas (PCTs induced in the same strain. We determined the three-dimensional orientation of chromosome 11 using a mouse chromosome 11 specific multicolor banding probe. We also examined the nuclear position of the small translocation chromosome T(X;11 which contains cytoband 11E2 and parts of E1. Chromosomes can point either with their centromeric or with their telomeric end toward the nuclear center or periphery, or their position is found in parallel to the nuclear border. In T38HT(X;11 nuclei, the most frequently observed orientation pattern was with both chromosomes 11 in parallel to the nuclear border (“PP”. PCT cells showed nuclei with two or more copies of chromosome 11. In PCTs, the most frequent orientation pattern was with one chromosome in parallel and the other pointing with its centromeric end toward the nuclear periphery (“CP”. There is a significant difference between the orientation patterns observed in T38HT(X;11 and in PCT nuclei (P < .0001.

  5. Distinct nuclear orientation patterns for mouse chromosome 11 in normal B lymphocytes

    NARCIS (Netherlands)

    Schmälter, A.K.; Kuzyk, A.; Righolt, C.H.; Neusser, M.; Steinlein, O.K.; Müller, S.; Mai, S.

    2014-01-01

    Background Characterizing the nuclear orientation of chromosomes in the three-dimensional (3D) nucleus by multicolor banding (mBANDing) is a new approach towards understanding nuclear organization of chromosome territories. An mBANDing paint is composed of multiple overlapping subchromosomal probes

  6. Nuclear envelope expansion is crucial for proper chromosomal segregation during a closed mitosis.

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    Takemoto, Ai; Kawashima, Shigehiro A; Li, Juan-Juan; Jeffery, Linda; Yamatsugu, Kenzo; Elemento, Olivier; Nurse, Paul

    2016-03-15

    Here, we screened a 10,371 library of diverse molecules using a drug-sensitive fission yeast strain to identify compounds which cause defects in chromosome segregation during mitosis. We identified a phosphorium-ylide-based compound Cutin-1 which inhibits nuclear envelope expansion and nuclear elongation during the closed mitosis of fission yeast, and showed that its target is the β-subunit of fatty acid synthase. A point mutation in the dehydratase domain of Fas1 conferred in vivo and in vitro resistance to Cutin-1. Time-lapse photomicrography showed that the bulk of the chromosomes were only transiently separated during mitosis, and nucleoli separation was defective. Subsequently sister chromatids re-associated leading to chromosomal mis-segregation. These segregation defects were reduced when the nuclear volume was increased and were increased when the nuclear volume was reduced. We propose that there needs to be sufficient nuclear volume to allow the nuclear elongation necessary during a closed mitosis to take place for proper chromosome segregation, and that inhibition of fatty acid synthase compromises nuclear elongation and leads to defects in chromosomal segregation. © 2016. Published by The Company of Biologists Ltd.

  7. Numerical Chromosome Errors in Day 7 Somatic Nuclear Transfer Bovine Blastocysts

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    Booth, Paul J.; VIUFF, Dorte; Tan, Shijian

    2002-01-01

    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...

  8. Analysis of chromosomal aberrations frequency, haematological parameters and received doses by nuclear medicine professionals.

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    Djokovic-Davidovic, Jelena; Milovanovic, Andjela; Milovanovic, Jovica; Antic, Vojislav; Gajic, Milan

    2016-01-01

    The purpose of this article was to analyse the impact of low-dose ionizing radiation to nuclear medicine professionals of the Nuclear Medicine Centre of Serbia (NMCRS). Data from the previous/initial and the last medical check-ups, obtained from the medical records of 65 employees from NMCRS, were analysed. A typical checkup, haematological parameters analysis, as well as special cytogenetical analyses, such as unstable chromosomal aberrations and micronucleus test, were carried out. For analyses of chromosomal aberrations the modified Moorhead's micro method was applied to the culture of peripheral blood lymphocytes and conventional cytogenetic technique of chromosomal aberrations was applied. The received cumulative 5-year dose was measured by personal inactive thermoluminescent dosimeters (TLD) calibrated into personal doses equivalent Hp(10). An increased frequency of all unstable chromosomal aberration forms, such as acentric chromosomes and isochromatid lesions, was noticed in the last periodical check-up as compared to the previous/initial checkups (pNuclear medicine employees have increased health risks and there is a need to monitor their health condition by periodical check-ups for prevention from occupational diseases (carcinoma).

  9. Localization of latency-associated nuclear antigen (LANA) on mitotic chromosomes

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    Rahayu, Retno; Ohsaki, Eriko [Division of Virology, Department of Microbiology and Immunology, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka 565-0871 (Japan); Omori, Hiroko [Central Instrumentation Laboratory Research Institute for Microbial Diseases (BIKEN), Osaka University, Osaka 565-0871 (Japan); Ueda, Keiji, E-mail: kueda@virus.med.osaka-u.ac.jp [Division of Virology, Department of Microbiology and Immunology, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka 565-0871 (Japan)

    2016-09-15

    In latent infection of Kaposi's sarcoma-associated herpesvirus (KSHV), viral gene expression is extremely limited and copy numbers of viral genomes remain constant. Latency-associated nuclear antigen (LANA) is known to have a role in maintaining viral genome copy numbers in growing cells. Several studies have shown that LANA is localized in particular regions on mitotic chromosomes, such as centromeres/pericentromeres. We independently examined the distinct localization of LANA on mitotic chromosomes during mitosis, using super-resolution laser confocal microscopy and correlative fluorescence microscopy–electron microscopy (FM-EM) analyses. We found that the majority of LANA were not localized at particular regions such as telomeres/peritelomeres, centromeres/pericentromeres, and cohesion sites, but at the bodies of condensed chromosomes. Thus, LANA may undergo various interactions with the host factors on the condensed chromosomes in order to tether the viral genome to mitotic chromosomes and realize faithful viral genome segregation during cell division. - Highlights: • This is the first report showing LANA dots on mitotic chromosomes by fluorescent microscopy followed by electron microscopy. • LANA dots localized randomly on condensed chromosomes other than centromere/pericentromere and telomere/peritelomre. • Cellular mitotic checkpoint should not be always involved in the segregation of KSHV genomes in the latency.

  10. Nuclei size in relation to nuclear status and aneuploidy rate for 13 chromosomes in donated four cells embryos

    DEFF Research Database (Denmark)

    Agerholm, I.E.; Hnida, C.; Cruger, D.G.

    2008-01-01

    Purpose The aim was to elucidate if the nuclear size and number are indicative of aberrant chromosome content in human blastomeres and embryos. Methods The number of nuclei and the nucleus and blastomere size were measured by a computer controlled system for multilevel analysis. Then the nuclei...... were enumerated for 13 chromosomes by a combination of PNA and DNA probes. Results In the mononucleated embryos there was no difference in the mean size of chromosomally normal and abnormal nuclei but a significant difference in the mean nuclei size of nuclei that had gained chromosomes compared...... to nuclei that had lost chromosomes. The nuclei from multinucleated blastomeres had a significant smaller mean size and the frequency of chromosomally aberrant blastomeres was significantly higher. Conclusion The mean nuclear size is not a marker for the chromosome content in mononucleated embryos. However...

  11. Numerical chromosome errors in day 7 somatic nuclear transfer bovine blastocysts

    DEFF Research Database (Denmark)

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

    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...... amino acids, myoinositol, sodium citrate, and 5% cattle serum in microwells for 7 days, at which time nuclei from all blastocysts were extracted and chromosome aberrations were evaluated using dual-color fluorescent in situ hybridization with bovine chromosome 6- and 7-specific probes. Five embryo clone......; 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...

  12. Chromosome conformation maps in fission yeast reveal cell cycle dependent sub nuclear structure.

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    Grand, Ralph S; Pichugina, Tatyana; Gehlen, Lutz R; Jones, M Beatrix; Tsai, Peter; Allison, Jane R; Martienssen, Robert; O'Sullivan, Justin M

    2014-11-10

    Successful progression through the cell cycle requires spatial and temporal regulation of gene transcript levels and the number, positions and condensation levels of chromosomes. Here we present a high resolution survey of genome interactions in Schizosaccharomyces pombe using synchronized cells to investigate cell cycle dependent changes in genome organization and transcription. Cell cycle dependent interactions were captured between and within S. pombe chromosomes. Known features of genome organization (e.g. the clustering of telomeres and retrotransposon long terminal repeats (LTRs)) were observed throughout the cell cycle. There were clear correlations between transcript levels and chromosomal interactions between genes, consistent with a role for interactions in transcriptional regulation at specific stages of the cell cycle. In silico reconstructions of the chromosome organization within the S. pombe nuclei were made by polymer modeling. These models suggest that groups of genes with high and low, or differentially regulated transcript levels have preferred positions within the S. pombe nucleus. We conclude that the S. pombe nucleus is spatially divided into functional sub-nuclear domains that correlate with gene activity. The observation that chromosomal interactions are maintained even when chromosomes are fully condensed in M phase implicates genome organization in epigenetic inheritance and bookmarking. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

  13. Nuclear and territorial topography of chromosome telomeres in human lymphocytes

    Czech Academy of Sciences Publication Activity Database

    Amrichová, J.; Lukášová, Emilie; Kozubek, Stanislav; Kozubek, Michal

    2003-01-01

    Roč. 289, č. 1 (2003), s. 11-26 ISSN 0014-4827 R&D Projects: GA MZd NC5955; GA MZd NC6987; GA AV ČR IBS5004010; GA ČR GA202/02/0804; GA ČR GA301/01/0186 Institutional research plan: CEZ:AV0Z5004920 Keywords : nuclear architecture * telomere * centromere Subject RIV: BO - Biophysics Impact factor: 3.949, year: 2003

  14. Nucleolus association of chromosomal domains is largely maintained in cellular senescence despite massive nuclear reorganisation.

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    Stefan Dillinger

    Full Text Available Mammalian chromosomes are organized in structural and functional domains of 0.1-10 Mb, which are characterized by high self-association frequencies in the nuclear space and different contact probabilities with nuclear sub-compartments. They exhibit distinct chromatin modification patterns, gene expression levels and replication timing. Recently, nucleolus-associated chromosomal domains (NADs have been discovered, yet their precise genomic organization and dynamics are still largely unknown. Here, we use nucleolus genomics and single-cell experiments to address these questions in human embryonic fibroblasts during replicative senescence. Genome-wide mapping reveals 1,646 NADs in proliferating cells, which cover about 38% of the annotated human genome. They are mainly heterochromatic and correlate with late replicating loci. Using Hi-C data analysis, we show that interactions of NADs dominate interphase chromosome contacts in the 10-50 Mb distance range. Interestingly, only minute changes in nucleolar association are observed upon senescence. These spatial rearrangements in subdomains smaller than 100 kb are accompanied with local transcriptional changes. In contrast, large centromeric and pericentromeric satellite repeat clusters extensively dissociate from nucleoli in senescent cells. Accordingly, H3K9me3-marked heterochromatin gets remodelled at the perinucleolar space as revealed by immunofluorescence analyses. Collectively, this study identifies connections between the nucleolus, 3D genome structure, and cellular aging at the level of interphase chromosome organization.

  15. Identification of Conserved MEL-28/ELYS Domains with Essential Roles in Nuclear Assembly and Chromosome Segregation.

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    Georgina Gómez-Saldivar

    2016-06-01

    Full Text Available Nucleoporins are the constituents of nuclear pore complexes (NPCs and are essential regulators of nucleocytoplasmic transport, gene expression and genome stability. The nucleoporin MEL-28/ELYS plays a critical role in post-mitotic NPC reassembly through recruitment of the NUP107-160 subcomplex, and is required for correct segregation of mitotic chromosomes. Here we present a systematic functional and structural analysis of MEL-28 in C. elegans early development and human ELYS in cultured cells. We have identified functional domains responsible for nuclear envelope and kinetochore localization, chromatin binding, mitotic spindle matrix association and chromosome segregation. Surprisingly, we found that perturbations to MEL-28's conserved AT-hook domain do not affect MEL-28 localization although they disrupt MEL-28 function and delay cell cycle progression in a DNA damage checkpoint-dependent manner. Our analyses also uncover a novel meiotic role of MEL-28. Together, these results show that MEL-28 has conserved structural domains that are essential for its fundamental roles in NPC assembly and chromosome segregation.

  16. Differential gene flow of mitochondrial and nuclear DNA markers among chromosomal races of Australian morabine grasshoppers (Vandiemenella, viatica species group).

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    Kawakami, T; Butlin, R K; Adams, M; Saint, K M; Paull, D J; Cooper, S J B

    2007-12-01

    Recent theoretical developments have led to a renewed interest in the potential role of chromosomal rearrangements in speciation. Australian morabine grasshoppers (genus Vandiemenella, viatica species group) provide an excellent study system to test this potential role of chromosomal rearrangements because they show extensive chromosomal variation and formed the basis of a classic chromosomal speciation model. There are three chromosomal races, viatica19, viatica17, and P24(XY), on Kangaroo Island, South Australia, forming five parapatric populations with four putative contact zones among them. We investigate the extent to which chromosomal variation among these populations may be associated with barriers to gene flow. Population genetic and phylogeographical analyses using 15 variable allozyme loci and the elongation factor-1alpha (EF-1alpha) gene indicate that the three races represent genetically distinct taxa. In contrast, analyses of the mitochondrial cytochrome c oxidase subunit I (COI) gene show the presence of three distinctive and geographically localized groups that do not correspond with the distribution of the chromosomal races. These discordant population genetic patterns are likely to result from introgressive hybridization between the chromosomal races and range expansions/contractions. Overall, these results suggest that reduction of nuclear gene flow may be associated with chromosomal variation, or underlying genetic variation linked with chromosomal variation, whereas mitochondrial gene flow appears to be independent of this variation in these morabine grasshoppers. The identification of an intact contact zone between P24(XY) and viatica17 offers considerable potential for further investigation of molecular mechanisms that maintain distinct nuclear genomes among the chromosomal races.

  17. 53BP1 nuclear bodies form around DNA lesions generated by mitotic transmission of chromosomes under replication stress

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    Lukas, Claudia; Savic, Velibor; Bekker-Jensen, Simon

    2011-01-01

    stress increases the frequency of chromosomal lesions that are transmitted to daughter cells. Throughout G1, these lesions are sequestered in nuclear compartments marked by p53-binding protein 1 (53BP1) and other chromatin-associated genome caretakers. We show that the number of such 53BP1 nuclear bodies...... increases after genetic ablation of BLM, a DNA helicase associated with dissolution of entangled DNA. Conversely, 53BP1 nuclear bodies are partially suppressed by knocking down SMC2, a condensin subunit required for mechanical stability of mitotic chromosomes. Finally, we provide evidence that 53BP1 nuclear...... bodies shield chromosomal fragile sites sequestered in these compartments against erosion. Together, these data indicate that restoration of DNA or chromatin integrity at loci prone to replication problems requires mitotic transmission to the next cell generations....

  18. Oocyte Polarization Is Coupled to the Chromosomal Bouquet, a Conserved Polarized Nuclear Configuration in Meiosis.

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    Yaniv M Elkouby

    2016-01-01

    Full Text Available The source of symmetry breaking in vertebrate oocytes is unknown. Animal-vegetal oocyte polarity is established by the Balbiani body (Bb, a conserved structure found in all animals examined that contains an aggregate of specific mRNAs, proteins, and organelles. The Bb specifies the oocyte vegetal pole, which is key to forming the embryonic body axes as well as the germline in most vertebrates. How Bb formation is regulated and how its asymmetric position is established are unknown. Using quantitative image analysis, we trace oocyte symmetry breaking in zebrafish to a nuclear asymmetry at the onset of meiosis called the chromosomal bouquet. The bouquet is a universal feature of meiosis where all telomeres cluster to one pole on the nuclear envelope, facilitating chromosomal pairing and meiotic recombination. We show that Bb precursor components first localize with the centrosome to the cytoplasm adjacent to the telomere cluster of the bouquet. They then aggregate around the centrosome in a specialized nuclear cleft that we identified, assembling the early Bb. We show that the bouquet nuclear events and the cytoplasmic Bb precursor localization are mechanistically coordinated by microtubules. Thus the animal-vegetal axis of the oocyte is aligned to the nuclear axis of the bouquet. We further show that the symmetry breaking events lay upstream to the only known regulator of Bb formation, the Bucky ball protein. Our findings link two universal features of oogenesis, the Bb and the chromosomal bouquet, to oocyte polarization. We propose that a meiotic-vegetal center couples meiosis and oocyte patterning. Our findings reveal a novel mode of cellular polarization in meiotic cells whereby cellular and nuclear polarity are aligned. We further reveal that in zygotene nests, intercellular cytoplasmic bridges remain between oocytes and that the position of the cytoplasmic bridge coincides with the location of the centrosome meiotic-vegetal organizing center

  19. Oocyte Polarization Is Coupled to the Chromosomal Bouquet, a Conserved Polarized Nuclear Configuration in Meiosis.

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    Elkouby, Yaniv M; Jamieson-Lucy, Allison; Mullins, Mary C

    2016-01-01

    The source of symmetry breaking in vertebrate oocytes is unknown. Animal-vegetal oocyte polarity is established by the Balbiani body (Bb), a conserved structure found in all animals examined that contains an aggregate of specific mRNAs, proteins, and organelles. The Bb specifies the oocyte vegetal pole, which is key to forming the embryonic body axes as well as the germline in most vertebrates. How Bb formation is regulated and how its asymmetric position is established are unknown. Using quantitative image analysis, we trace oocyte symmetry breaking in zebrafish to a nuclear asymmetry at the onset of meiosis called the chromosomal bouquet. The bouquet is a universal feature of meiosis where all telomeres cluster to one pole on the nuclear envelope, facilitating chromosomal pairing and meiotic recombination. We show that Bb precursor components first localize with the centrosome to the cytoplasm adjacent to the telomere cluster of the bouquet. They then aggregate around the centrosome in a specialized nuclear cleft that we identified, assembling the early Bb. We show that the bouquet nuclear events and the cytoplasmic Bb precursor localization are mechanistically coordinated by microtubules. Thus the animal-vegetal axis of the oocyte is aligned to the nuclear axis of the bouquet. We further show that the symmetry breaking events lay upstream to the only known regulator of Bb formation, the Bucky ball protein. Our findings link two universal features of oogenesis, the Bb and the chromosomal bouquet, to oocyte polarization. We propose that a meiotic-vegetal center couples meiosis and oocyte patterning. Our findings reveal a novel mode of cellular polarization in meiotic cells whereby cellular and nuclear polarity are aligned. We further reveal that in zygotene nests, intercellular cytoplasmic bridges remain between oocytes and that the position of the cytoplasmic bridge coincides with the location of the centrosome meiotic-vegetal organizing center. These results

  20. Culture, characteristics and chromosome complement of Siberian tiger fibroblasts for nuclear transfer.

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    Song, Jimei; Hua, Song; Song, Kai; Zhang, Yong

    2007-01-01

    Tiger (Panthera tigris Linnaeus, 1758) is a characteristic species of Asia, which is in severe danger. Siberian tiger (Panthera tigris altaica) is the largest one of the five existent tiger subspecies. It is extremely endangered. One new way for tiger protection and rescue is to study interspecies cloning. But there is few research data about Siberian tiger. In this study, we cultured Siberian tiger fibroblasts in vitro, analyzed their biological characteristics, chromosomes, and cell cycles, to provide not only nuclear donors with good morphology, normal biological characteristics, and chromosome quantity for tiger interspecies cloning, but also reliable data for further studying Siberian tiger. The results indicated that Siberian tiger ear fibroblasts can be successfully obtained by tissue culture either with or without overnight cold digestion, the cultured cells were typical fibroblasts with normal morphology, growth curve, and chromosome quantity; G0/G1 percentage increased and S percentage decreased with the confluence of cells. G0/G1 and S stage rate was significantly different between 40-50% and 80-90%, 95-100% confluence; there is no distinct difference between 80-90% and 95-100% confluence. The cells at the same density (80-90% confluence) were treated with or without 0.5% serum starving, GO/G1 rate of the former was higher than the latter, but the difference was not significant. GO/G1 proportion of 95-100% confluence was slightly higher than serum starving (80-90% confluence), but no significant difference. Therefore, the Siberian tiger fibroblasts we cultured in vitro can be used as donor cells, and the donor cells do not need to be treated with normal serum starvation during nuclear transfer; if we will just consider the rate of the G0/G1 stage cells, serum starvation can be replaced by confluence inhibition when cultured cells were more than 80-90% confluence.

  1. Nuclear volume differences between balanced and unbalanced spermatozoa in chromosomal translocation carriers.

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    Rouen, Alexandre; Lavillaureix, Alinoë; Hyon, Capucine; Heide, Solveig; Clède, Sylvain; Balet, Richard; Kott, Esther; Cassuto, Nino Guy; Siffroi, Jean-Pierre

    2015-03-01

    While chromosomal translocations are usually associated with a normal phenotype, they can still cause male infertility as well as recurrent miscarriages and fetal malformations related to their transmission in an unbalanced state. The distinction between balanced and unbalanced spermatozoa on morphological criteria is still unfeasible. However, we previously showed that: i) spermatozoa with an unbalanced content have a higher rate of DNA fragmentation; and ii) that density gradient centrifugation partially separates balanced from unbalanced sperm cells. We hypothesized that a chromosomal imbalance could alter the fine spermatic nuclear architecture and consequently the condensation of DNA, thus modifying normal sperm density. Spermatic nuclear volumes in four translocation carriers were analyzed using confocal microscopy. Secondarily, FISH analysis was used to establish the segregation mode of each spermatozoon. We found the average spermatic nuclei size to be higher among unbalanced spermatozoa in all patients but one. All the unbalanced modes were associated with larger nuclei in two patients, while this was the case for the 3:1 mode only in the other two, suggesting an abnormal condensation. This could be the first step in elaborating a procedure to completely eliminate unbalanced spermatozoa from semen prior to in vitro fertilization. Copyright © 2014 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

  2. An influence of occupational exposure on level of chromosome aberrations in nuclear power plant workers

    International Nuclear Information System (INIS)

    Birute Griciene; Grazina Slapsyte

    2007-01-01

    Complete text of publication follows. Objective. The workers of Ignalina Nuclear Power Plant (INPP) receive the highest occupational ionising radiation doses in Lithuania. Their occupational exposure results mainly from external low LET gamma radiation. Some workers receive additional internal and neutron exposure. Though exposure doses are generally low and don't exceed the annual dose limit, the higher doses are obtained during outages. The aim of the present study was to analyse chromosome aberration frequencies in lymphocytes of INPP workers exposed to the different types of ionising radiation. Methods. The blood sampling of 52 INPP male workers was performed in 2004-2006. For 29 workers radiation exposure resulted from the external gamma rays only. Their mean annual dose averaged over the 3-year period prior blood sampling was 11.7±8.7 mSv. The mean cumulative dose - 197.7±174.7 mSv. 15 workers had an intake of gamma radionuclides ( 60 Co, 137 Cs), contributing to the doses less than 0.1 mSv. Their mean cumulative dose - 278.2±191.9 mSv. The mean annual dose averaged over the 3-year period prior blood sampling was 11.8±5.3 mSv. For 8 subjects neutron doses below 0.2 mSv were recorded. Their mean annual dose averaged over the 3-year period prior blood sampling was 7.0±2.9 mSv. The mean cumulative dose was 241.8±93.0 mSv. Heparinized venous blood samples were taken and cultures were initiated according to the standard procedures. Phytohaemagglutinin (7.8 μg/ml) stimulated cultures were incubated at 37degC for 72 hours in RPMI 1640 medium supplemented with 12% heat-inactivated newborn calf serum, 40 μg/ml gentamycin. Colchicine was added to the culture during the initiation at a final concentration of 0,25 μg/ml. The harvested lymphocytes were treated with hypotonic KCl (0,075 M) and then fixed in methanol-glacial acetic acid (3:1). Flame-dried slides were stained with Giemsa, coded and scored blind. Generally 500 first-division cells per individual were

  3. Investigation of the chromosome regions with significant affinity for the nuclear envelope in fruit fly--a model based approach.

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    Nicholas Allen Kinney

    Full Text Available Three dimensional nuclear architecture is important for genome function, but is still poorly understood. In particular, little is known about the role of the "boundary conditions"--points of attachment between chromosomes and the nuclear envelope. We describe a method for modeling the 3D organization of the interphase nucleus, and its application to analysis of chromosome-nuclear envelope (Chr-NE attachments of polytene (giant chromosomes in Drosophila melanogaster salivary glands. The model represents chromosomes as self-avoiding polymer chains confined within the nucleus; parameters of the model are taken directly from experiment, no fitting parameters are introduced. Methods are developed to objectively quantify chromosome territories and intertwining, which are discussed in the context of corresponding experimental observations. In particular, a mathematically rigorous definition of a territory based on convex hull is proposed. The self-avoiding polymer model is used to re-analyze previous experimental data; the analysis suggests 33 additional Chr-NE attachments in addition to the 15 already explored Chr-NE attachments. Most of these new Chr-NE attachments correspond to intercalary heterochromatin--gene poor, dark staining, late replicating regions of the genome; however, three correspond to euchromatin--gene rich, light staining, early replicating regions of the genome. The analysis also suggests 5 regions of anti-contact, characterized by aversion for the NE, only two of these correspond to euchromatin. This composition of chromatin suggests that heterochromatin may not be necessary or sufficient for the formation of a Chr-NE attachment. To the extent that the proposed model represents reality, the confinement of the polytene chromosomes in a spherical nucleus alone does not favor the positioning of specific chromosome regions at the NE as seen in experiment; consequently, the 15 experimentally known Chr-NE attachment positions do not

  4. [The nuclear matrix proteins (mol. mass 38 and 50 kDa) are transported by chromosomes in mitosis].

    Science.gov (United States)

    Murasheva, M I; Chentsov, Iu S

    2010-01-01

    It was shown by immunofluorescence method that serum M68 and serum K43 from patients with autoimmune disease stain interphase nuclei and periphery of mitotic chromosomes of pig kidney cells. Western blotting reveals the polypeptide with mol. mass of 50 kDa in serum M68, and the polypeptide with mol. mass of 38 kDa in serum K43. In the nuclear protein matrix, the antibodies to protein with mol. mass of 38 kDa stained only nucleolar periphery, while the antibodies to the protein with mol. mass of 50 kDa stained both the nucleolar periphery and all the interphase nucleus. It shows that among all components of nuclear protein matrix (lamina, internuclear network, residual nucleoli) only nucleolar periphery contains the 38 kDa protein, while the 50 kDa protein is a part of residual nucleolar periphery and takes part in nuclear protein network formation. In the interphase cells, both proteins were in situ localized in the nuclei, but one of them with mol. mass of 50 kDa was in the form of small clearly outlined granules, while the other (38 kDa) was in the form of small bright granules against the background of diffusely stained nuclei. Both proteins were also revealed as continuous ring around nucleolar periphery. During all mitotic stages, the 50 kDa protein was seen on the chromosomal periphery as a cover, and the 38 kDa protein formed separate fragments and granules around them. After nuclear and chromosome decondensation induced by hypotonic treatment, both antibodies stain interphase nuclei in diffuse manner, but in mitotic cells they stained the surface of the swollen chromosomes. The polypeptide with mol. mass of 50 kDa maintained strong connection with chromosome periphery both in norm and under condition of decondensation induced by hypotonic treatment and at subsequent recondensation in isotonic medium. In contrast, the protein with mol. mass of 38 kDa partially lost the contact with a chromosome during recondensation appearing also in the form of granules in

  5. Dynamic chromosomal rearrangements in Hodgkin's lymphoma are due to ongoing three-dimensional nuclear remodeling and breakage-bridge-fusion cycles.

    Science.gov (United States)

    Guffei, Amanda; Sarkar, Rahul; Klewes, Ludger; Righolt, Christiaan; Knecht, Hans; Mai, Sabine

    2010-12-01

    Hodgkin's lymphoma is characterized by the presence of mono-nucleated Hodgkin cells and bi- to multi-nucleated Reed-Sternberg cells. We have recently shown telomere dysfunction and aberrant synchronous/asynchronous cell divisions during the transition of Hodgkin cells to Reed-Sternberg cells.1 To determine whether overall changes in nuclear architecture affect genomic instability during the transition of Hodgkin cells to Reed-Sternberg cells, we investigated the nuclear organization of chromosomes in these cells. Three-dimensional fluorescent in situ hybridization revealed irregular nuclear positioning of individual chromosomes in Hodgkin cells and, more so, in Reed-Sternberg cells. We characterized an increasingly unequal distribution of chromosomes as mono-nucleated cells became multi-nucleated cells, some of which also contained chromosome-poor 'ghost' cell nuclei. Measurements of nuclear chromosome positions suggested chromosome overlaps in both types of cells. Spectral karyotyping then revealed both aneuploidy and complex chromosomal rearrangements: multiple breakage-bridge-fusion cycles were at the origin of the multiple rearranged chromosomes. This conclusion was challenged by super resolution three-dimensional structured illumination imaging of Hodgkin and Reed-Sternberg nuclei. Three-dimensional super resolution microscopy data documented inter-nuclear DNA bridges in multi-nucleated cells but not in mono-nucleated cells. These bridges consisted of chromatids and chromosomes shared by two Reed-Sternberg nuclei. The complexity of chromosomal rearrangements increased as Hodgkin cells developed into multi-nucleated cells, thus indicating tumor progression and evolution in Hodgkin's lymphoma, with Reed-Sternberg cells representing the highest complexity in chromosomal rearrangements in this disease. This is the first study to demonstrate nuclear remodeling and associated genomic instability leading to the generation of Reed-Sternberg cells of Hodgkin's lymphoma

  6. Formation of Nup98-containing nuclear bodies in HeLa sublines is linked to genomic rearrangements affecting chromosome 11.

    Science.gov (United States)

    Romana, Serge; Radford-Weiss, Isabelle; Lapierre, Jean-Michel; Doye, Valérie; Geoffroy, Marie-Claude

    2016-09-01

    Nup98 is an important component of the nuclear pore complex (NPC) and also a rare but recurrent target for chromosomal translocation in leukaemogenesis. Nup98 contains multiple cohesive Gly-Leu-Phe-Gly (GLFG) repeats that are critical notably for the formation of intranuclear GLFG bodies. Previous studies have reported the existence of GLFG bodies in cells overexpressing exogenous Nup98 or in a HeLa subline (HeLa-C) expressing an unusual elevated amount of endogenous Nup98. Here, we have analysed the presence of Nup98-containing bodies in several human cell lines. We found that HEp-2, another HeLa subline, contains GLFG bodies that are distinct from those identified in HeLa-C. Rapid amplification of cDNA ends (RACE) revealed that HEp-2 cells express additional truncated forms of Nup98 fused to a non-coding region of chromosome 11q22.1. Cytogenetic analyses using FISH and array-CGH further revealed chromosomal rearrangements that were distinct from those observed in leukaemic cells. Indeed, HEp-2 cells feature a massive amplification of juxtaposed NUP98 and 11q22.1 loci on a chromosome marker derived from chromosome 3. Unexpectedly, minor co-amplifications of NUP98 and 11q22.1 loci were also observed in other HeLa sublines, but on rearranged chromosomes 11. Altogether, this study reveals that distinct genomic rearrangements affecting NUP98 are associated with the formation of GLFG bodies in specific HeLa sublines.

  7. Frequencies of chromosomal inversions in Drosophila melanogaster in Fukushima after the nuclear power plant accident.

    Directory of Open Access Journals (Sweden)

    Masanobu Itoh

    Full Text Available In order to investigate genetic impact of a large amount of radionuclides released by the Fukushima Dai-ichi Nuclear Power Plant accident in 2011, we surveyed 2,304 haploid genomes of Drosophila melanogaster collected in three localities in Fukushima in 2012 and 2013 for chromosomal inversions. No unique inversion was found in 298 genomes in 2012 and only two in 2,006 genomes in 2013. The observed frequencies were even lower than the long-term average frequency of unique inversions in Japan. The common cosmopolitan inversions were also examined in Fukushima, Kyoto, and Iriomote (Okinawa in 2012. Among three samples in Fukushima, the flies in Iizaka, where environmental radiation level was the highest, showed the lowest frequency of In(2Lt, but the highest frequency of In(3RP, contrary to the expectation of decreasing of their frequencies in higher polluted areas. These results suggest that, at this level of genetic analysis, Fukushima populations of D. melanogaster would not have been negatively impacted following the release of radionuclides. Transposable P-element mobility was not likely to induce DNA damage solely or synergistically with radioactivity, because their transposition activity was totally repressed in the Fukushima strains. However, it should be noted that, because of limitations in access to the exclusion zone, we could only sample the populations in areas of relatively low radioactive contamination (0.39-0.63 μSv/h. Therefore, the present study is likely to be underpowered to detect any effects that might be expected in heavily contaminated areas.

  8. Frequencies of chromosomal inversions in Drosophila melanogaster in Fukushima after the nuclear power plant accident.

    Science.gov (United States)

    Itoh, Masanobu; Kajihara, Ryutaro; Kato, Yasuko; Takano-Shimizu, Toshiyuki; Inoue, Yutaka

    2018-01-01

    In order to investigate genetic impact of a large amount of radionuclides released by the Fukushima Dai-ichi Nuclear Power Plant accident in 2011, we surveyed 2,304 haploid genomes of Drosophila melanogaster collected in three localities in Fukushima in 2012 and 2013 for chromosomal inversions. No unique inversion was found in 298 genomes in 2012 and only two in 2,006 genomes in 2013. The observed frequencies were even lower than the long-term average frequency of unique inversions in Japan. The common cosmopolitan inversions were also examined in Fukushima, Kyoto, and Iriomote (Okinawa) in 2012. Among three samples in Fukushima, the flies in Iizaka, where environmental radiation level was the highest, showed the lowest frequency of In(2L)t, but the highest frequency of In(3R)P, contrary to the expectation of decreasing of their frequencies in higher polluted areas. These results suggest that, at this level of genetic analysis, Fukushima populations of D. melanogaster would not have been negatively impacted following the release of radionuclides. Transposable P-element mobility was not likely to induce DNA damage solely or synergistically with radioactivity, because their transposition activity was totally repressed in the Fukushima strains. However, it should be noted that, because of limitations in access to the exclusion zone, we could only sample the populations in areas of relatively low radioactive contamination (0.39-0.63 μSv/h). Therefore, the present study is likely to be underpowered to detect any effects that might be expected in heavily contaminated areas.

  9. Assignment of the nuclear mitotic apparatus protein NuMA gene to human chromosome 11q13

    Energy Technology Data Exchange (ETDEWEB)

    Sparks, C.A.; Bangs, P.L.; Lawrence, J.B.; Fey, E.G.; McNeil, G.P. (Univ. of Massachusetts Medical School, Worcester, MA (United States))

    1993-07-01

    A monoclonal antibody that was specific for a nuclear matrix protein was obtained and used to screen a human [lambda]gt11 expression library. Several partial cDNA clones were isolated and sequenced. The sequence for this protein was shown to be identical to that of NuMA, a 236-kDa nuclear mitotic spindle apparatus protein. NuMA has been recently characterized by two independent studies, and is thought to be part of a family of proteins that is required for the completion of mitosis. In this report, the chromosomal localization and copy number of the NuMA gene are analyzed using cDNA clones. High-resolution in situ hybridization reveals a single pair of signals on sister chromatids of human chromosome 11 at band q13. Stringent Southern analysis of human genomic DNA resulted in simple restriction patterns. These results together indicate that the NuMA gene is present as a single copy on human chromosome 11q13. 12 refs., 1 fig.

  10. T Cell Receptor-induced Nuclear Factor κB (NF-κB) Signaling and Transcriptional Activation Are Regulated by STIM1- and Orai1-mediated Calcium Entry.

    Science.gov (United States)

    Liu, Xiaohong; Berry, Corbett T; Ruthel, Gordon; Madara, Jonathan J; MacGillivray, Katelyn; Gray, Carolyn M; Madge, Lisa A; McCorkell, Kelly A; Beiting, Daniel P; Hershberg, Uri; May, Michael J; Freedman, Bruce D

    2016-04-15

    T cell activation following antigen binding to the T cell receptor (TCR) involves the mobilization of intracellular Ca(2+) to activate the key transcription factors nuclear factor of activated T lymphocytes (NFAT) and NF-κB. The mechanism of NFAT activation by Ca(2+) has been determined. However, the role of Ca(2+) in controlling NF-κB signaling is poorly understood, and the source of Ca(2+) required for NF-κB activation is unknown. We demonstrate that TCR- but not TNF-induced NF-κB signaling upstream of IκB kinase activation absolutely requires the influx of extracellular Ca(2+) via STIM1-dependent Ca(2+) release-activated Ca(2+)/Orai channels. We further show that Ca(2+) influx controls phosphorylation of the NF-κB protein p65 on Ser-536 and that this posttranslational modification controls its nuclear localization and transcriptional activation. Notably, our data reveal that this role for Ca(2+) is entirely separate from its upstream control of IκBα degradation, thereby identifying a novel Ca(2+)-dependent distal step in TCR-induced NF-κB activation. Finally, we demonstrate that this control of distal signaling occurs via Ca(2+)-dependent PKCα-mediated phosphorylation of p65. Thus, we establish the source of Ca(2+) required for TCR-induced NF-κB activation and define a new distal Ca(2+)-dependent checkpoint in TCR-induced NF-κB signaling that has broad implications for the control of immune cell development and T cell functional specificity. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  11. Interleukin-1/toll-like receptor-induced nuclear factor kappa B signaling participates in intima hyperplasia after carotid artery balloon injury in goto-kakizaki rats: a potential target therapy pathway.

    Directory of Open Access Journals (Sweden)

    Xiaotian Zhang

    Full Text Available The value of restenosis after percutaneous coronary intervention (PCI is recognized worldwide, especially for diabetic patients. Interleukin-1/Toll-like receptor (IL-1/TLR signaling is involved in innate and adaptive immune responses, but whether and how the IL-1/TLR-induced nuclear factor kappa B (NFκB pathway plays key roles in intimal formation is unclear. The underlying mechanism of intima hyperplasia was investigated with a model of carotid balloon injury in Goto-Kakizaki (GK and Wistar rats and with lipopolysaccharide-stimulated macrophages. Elastic-van Gieson staining showed the medial area peakedon Day 3 post-injury and decreased by Day 7 post-injury in both GK and Wistar rats. The N/M at Day 7 in GK rats was significantly higher than in Wistar rats (p<0.001. The percent of 5-ethynyl-2'-deoxyuridine (EdU staining-positive cells on Day 3 post-injury was greater than seen on Day 7 post-injury in GK and Wistar rats. The percent of EdU-positive cells on Days 3 and 7 post-injury in Wistar rats was less than that found in GK rats (p<0.01; p<0.05. NFκBp65 immunostaining had increased by Day 7 post-injury. Agilent Whole Genome Oligo Microarray verified that the IL-1/TLR-induced NFκB pathway was activated by carotid balloon injury. TLR4, IL-1 receptor associated kinase, inhibitors α of NFκB, human antigen R, c-Myc (Proto-Oncogene Proteins, EGF-like module-containing mucin-like hormone receptor-like 1 and Interleukin-6 were up-regulated or down-regulated according to immunochemistry, quantitative real-time PCR, Western blotting and Enzyme linked immunosorbent assay. Overall, we conclude that the IL-1/TLR-induced NFκB pathway participates in the intimal hyperplasia after carotid injury in GK and Wistar rats and that GK rats respond more intensely to the inflammation than Wistar rats.

  12. Intra-Nuclear Single-Particle Tracking (I-SPT) to Reveal the Functional Architecture of Chromosomes.

    Science.gov (United States)

    Récamier, Vincent

    2016-01-01

    Chromosome architecture needs to be investigated in relation with the chemical function of DNA. The kinetics of gene expression, DNA replication, and repair are driven by the mechanisms by which a functional nuclear protein finds its substrate in the nucleus. Single-particle tracking (SPT) is a method to quantify fluorescent molecules dynamics from the tracks of the single molecules recorded by high-resolution microscopes. SPT offers direct observation of the movement and single-molecule resolution. Usually SPT is performed on membranes because of higher contrast. Here, we introduce a novel method to record the trajectories of weakly fluorescent molecules in the nucleus of living cells. I-SPT uses some specific detection and analysis tools to enable the computation of reliable statistics on nuclear particle movement.

  13. Calibration of chromosomal aberrations in the National Institute of Nuclear Research; Calibracion de aberraciones cromosomicas en el ININ

    Energy Technology Data Exchange (ETDEWEB)

    Guerrero C, C.; Arceo M, C.; Brena V, M. [ININ, 52750 La Marquesa, Estado de Mexico (Mexico)]. e-mail: cgc@nuclear.inin.mx

    2008-07-01

    In the laboratory of biological dosimetry of the National Institute of Nuclear Research one carried out a calibration of chromosomal aberrations. The result obtained by the different participants does not mark to significant differences between the readings of the cells and the considered one of dose for each one of the cases. The biological material for this intercomparison was prepared in the Republic of Argentina like part of the activities of the Project Regional OIEA-RLA/9/054 {sup S}trengthening of the National Systems for the Preparation and Answer in Radiological and Nuclear Emergencies{sup .} In this regional project participates seven countries of the area and in October of this year will be presented the results of each one of them. Part of the objectives of this project is the one to conform a network of mutual aid in case of radiological accidents for which the participants must unify criteria. (Author)

  14. Role of chromosome stability and telomere length in the production of viable cell lines for somatic cell nuclear transfer

    Directory of Open Access Journals (Sweden)

    Betts Dean H

    2006-08-01

    Full Text Available Abstract Background Somatic cell nuclear transfer (SCNT provides an appealing alternative for the preservation of genetic material in non-domestic and endangered species. An important prerequisite for successful SCNT is the availability of good quality donor cells, as normal embryo development is dependent upon proper reprogramming of the donor genome so that embryonic genes can be appropriately expressed. The characteristics of donor cell lines and their ability to produce embryos by SCNT were evaluated by testing the effects of tissue sample collection (DART biopsy, PUNCH biopsy, post-mortem EAR sample and culture initiation (explant, collagenase digestion techniques. Results Differences in initial sample size based on sample collection technique had an effect on the amount of time necessary for achieving primary confluence and the number of population doublings (PDL produced. Thus, DART and PUNCH biopsies resulted in cultures with decreased lifespans (50 PDL and chromosomally stable (>70% normal cells at 20 PDL cultures produced by post-mortem EAR samples. Chromosome stability was influenced by sample collection technique and was dependent upon the culture's initial telomere length and its rate of shortening over cell passages. Following SCNT, short-lived cultures resulted in significantly lower blastocyst development (≤ 0.9% compared to highly proliferative cultures (11.8%. Chromosome stability and sample collection technique were significant factors in determining blastocyst development outcome. Conclusion These data demonstrate the influence of culture establishment techniques on cell culture characteristics, including the viability, longevity and normality of cells. The identification of a quantifiable marker associated with SCNT embryo developmental potential, chromosome stability, provides a means by which cell culture conditions can be monitored and improved.

  15. Variation in chromosome numbers and nuclear DNA contents in genetic resources of Lactuca L. species (Asteraceae)

    Czech Academy of Sciences Publication Activity Database

    Doležalová, I.; Lebeda, A.; Janeček, J.; Čihalíková, Jarmila; Křístková, E.; Vránová, O.

    2002-01-01

    Roč. 49, č. 4 (2002), s. 385-397 ISSN 0925-9864 R&D Projects: GA AV ČR IAA6038204; GA AV ČR IBS5038104 Institutional research plan: CEZ:AV0Z5038910 Keywords : Asteraceae * Chromosome number * Flow cytometry Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 0.579, year: 2002

  16. Nuclear pore complex evolution: a trypanosome Mlp analogue functions in chromosomal segregation but lacks transcriptional barrier activity.

    Science.gov (United States)

    Holden, Jennifer M; Koreny, Ludek; Obado, Samson; Ratushny, Alexander V; Chen, Wei-Ming; Chiang, Jung-Hsien; Kelly, Steven; Chait, Brian T; Aitchison, John D; Rout, Michael P; Field, Mark C

    2014-05-01

    The nuclear pore complex (NPC) has dual roles in nucleocytoplasmic transport and chromatin organization. In many eukaryotes the coiled-coil Mlp/Tpr proteins of the NPC nuclear basket have specific functions in interactions with chromatin and defining specialized regions of active transcription, whereas Mlp2 associates with the mitotic spindle/NPC in a cell cycle-dependent manner. We previously identified two putative Mlp-related proteins in African trypanosomes, TbNup110 and TbNup92, the latter of which associates with the spindle. We now provide evidence for independent ancestry for TbNup92/TbNup110 and Mlp/Tpr proteins. However, TbNup92 is required for correct chromosome segregation, with knockout cells exhibiting microaneuploidy and lowered fidelity of telomere segregation. Further, TbNup92 is intimately associated with the mitotic spindle and spindle anchor site but apparently has minimal roles in control of gene transcription, indicating that TbNup92 lacks major barrier activity. TbNup92 therefore acts as a functional analogue of Mlp/Tpr proteins, and, together with the lamina analogue NUP-1, represents a cohort of novel proteins operating at the nuclear periphery of trypanosomes, uncovering complex evolutionary trajectories for the NPC and nuclear lamina.

  17. The Precarious Prokaryotic Chromosome

    Science.gov (United States)

    2014-01-01

    Evolutionary selection for optimal genome preservation, replication, and expression should yield similar chromosome organizations in any type of cells. And yet, the chromosome organization is surprisingly different between eukaryotes and prokaryotes. The nuclear versus cytoplasmic accommodation of genetic material accounts for the distinct eukaryotic and prokaryotic modes of genome evolution, but it falls short of explaining the differences in the chromosome organization. I propose that the two distinct ways to organize chromosomes are driven by the differences between the global-consecutive chromosome cycle of eukaryotes and the local-concurrent chromosome cycle of prokaryotes. Specifically, progressive chromosome segregation in prokaryotes demands a single duplicon per chromosome, while other “precarious” features of the prokaryotic chromosomes can be viewed as compensations for this severe restriction. PMID:24633873

  18. Chromatin structure and replication origins: determinants of chromosome replication and nuclear organization.

    Science.gov (United States)

    Smith, Owen K; Aladjem, Mirit I

    2014-10-09

    The DNA replication program is, in part, determined by the epigenetic landscape that governs local chromosome architecture and directs chromosome duplication. Replication must coordinate with other biochemical processes occurring concomitantly on chromatin, such as transcription and remodeling, to insure accurate duplication of both genetic and epigenetic features and to preserve genomic stability. The importance of genome architecture and chromatin looping in coordinating cellular processes on chromatin is illustrated by two recent sets of discoveries. First, chromatin-associated proteins that are not part of the core replication machinery were shown to affect the timing of DNA replication. These chromatin-associated proteins could be working in concert, or perhaps in competition, with the transcriptional machinery and with chromatin modifiers to determine the spatial and temporal organization of replication initiation events. Second, epigenetic interactions are mediated by DNA sequences that determine chromosomal replication. In this review, we summarize recent findings and current models linking spatial and temporal regulation of the replication program with epigenetic signaling. We discuss these issues in the context of the genome's three-dimensional structure with an emphasis on events occurring during the initiation of DNA replication. Published by Elsevier Ltd.

  19. Genome-wide analysis of host-chromosome binding sites for Epstein-Barr Virus Nuclear Antigen 1 (EBNA1

    Directory of Open Access Journals (Sweden)

    Wang Pu

    2010-10-01

    Full Text Available Abstract The Epstein-Barr Virus (EBV Nuclear Antigen 1 (EBNA1 protein is required for the establishment of EBV latent infection in proliferating B-lymphocytes. EBNA1 is a multifunctional DNA-binding protein that stimulates DNA replication at the viral origin of plasmid replication (OriP, regulates transcription of viral and cellular genes, and tethers the viral episome to the cellular chromosome. EBNA1 also provides a survival function to B-lymphocytes, potentially through its ability to alter cellular gene expression. To better understand these various functions of EBNA1, we performed a genome-wide analysis of the viral and cellular DNA sites associated with EBNA1 protein in a latently infected Burkitt lymphoma B-cell line. Chromatin-immunoprecipitation (ChIP combined with massively parallel deep-sequencing (ChIP-Seq was used to identify cellular sites bound by EBNA1. Sites identified by ChIP-Seq were validated by conventional real-time PCR, and ChIP-Seq provided quantitative, high-resolution detection of the known EBNA1 binding sites on the EBV genome at OriP and Qp. We identified at least one cluster of unusually high-affinity EBNA1 binding sites on chromosome 11, between the divergent FAM55 D and FAM55B genes. A consensus for all cellular EBNA1 binding sites is distinct from those derived from the known viral binding sites, suggesting that some of these sites are indirectly bound by EBNA1. EBNA1 also bound close to the transcriptional start sites of a large number of cellular genes, including HDAC3, CDC7, and MAP3K1, which we show are positively regulated by EBNA1. EBNA1 binding sites were enriched in some repetitive elements, especially LINE 1 retrotransposons, and had weak correlations with histone modifications and ORC binding. We conclude that EBNA1 can interact with a large number of cellular genes and chromosomal loci in latently infected cells, but that these sites are likely to represent a complex ensemble of direct and indirect EBNA

  20. Chromosomal locations of three human nuclear genes (RPSM12, TUFM, and AFG3L1) specifying putative components of the mitochondrial gene expression apparatus.

    Science.gov (United States)

    Shah, Z H; Migliosi, V; Miller, S C; Wang, A; Friedman, T B; Jacobs, H T

    1998-03-15

    We have mapped the chromosomal locations of three human nuclear genes for putative components of the apparatus of mitochondrial gene expression, using a combination of in situ hybridization and interspecies hybrid mapping. The genes RPMS12 (mitoribosomal protein S12, a conserved protein component of the mitoribosomal accuracy center), TUFM (mitochondrial elongation factor EF-Tu), and AFG3L1 (similar to the yeast genes Afg3 and Rca1 involved in the turnover of mistranslated or misfolded mtDNA-encoded polypeptides) were initially characterized by a combination of database sequence analysis, PCR, cloning, and DNA sequencing. RPMS12 maps to chromosome 19q13.1, close to the previously mapped gene for autosomal dominant hearing loss DFNA4. The TUFM gene is located on chromosome 16p11.2, with a putative pseudogene or variant (TUFML) located very close to the centromere of chromosome 17. AFG3L1 is located on chromosome 16q24, very close to the telomere. By virtue of their inferred functions in mitochondria, these genes should be regarded as candidates of disorders sharing features with mitochondrial disease syndromes, such as sensorineural deafness, diabetes, and retinopathy.

  1. The radiosensitivities of the lymphocyte chromosomes of the four mammalian species abundant in the environs of the Philippine Nuclear Power Plant-I

    International Nuclear Information System (INIS)

    Medina, F.I.S. III.

    1981-10-01

    The peripheral blood lymphocyte chromosomes of the Filipino, the carabao, the goat, and the ricefield rat, four mammalian species found abundant in the environs of the Philippine Nuclear Power Plant (PNPP-I) in Morong, Bataan, were studied to establish their radiosensitivities and to explore their possible use as biological indicator of radiation effects. The four mammalian species were found to be radiosensitive. Chromosome aberration was induced by gamma-irradiation of whole venous blood. By cytogenetic technique the aberrant chromosomes were evaluated. The aberrant chromosomes may be categorized into chromatid and chromosome types. Of the types seen, it was concluded that dicentrics are the most reliable indicator of radiation effects. In the course of this study a suitable medium was formualted and was found competitive with a commercially prepared medium. The radiosensitivity of the four species based on the frequency of dicentrics differs from each other. A calibration curve was constructed to relate exposure to the observed incidence of dicentrics. This curve is very important in the calculation of the dose corresponding to the observed dicentric yield in case of accidental release of radioactivity in the PNPP-I site. (author)

  2. Live embryo imaging to follow cell cycle and chromosomes stability after nuclear transfer.

    Science.gov (United States)

    Balbach, Sebastian T; Boiani, Michele

    2015-01-01

    Nuclear transfer (NT) into mouse oocytes yields a transcriptionally and functionally heterogeneous population of cloned embryos. Most studies of NT embryos consider only embryos at predefined key stages (e.g., morula or blastocyst), that is, after the bulk of reprogramming has taken place. These retrospective approaches are of limited use to elucidate mechanisms of reprogramming and to predict developmental success. Observing cloned embryo development using live embryo cinematography has the potential to reveal otherwise undetectable embryo features. However, light exposure necessary for live cell cinematography is highly toxic to cloned embryos. Here we describe a protocol for combined bright-field and fluorescence live-cell imaging of histone H2b-GFP expressing mouse embryos, to record cell divisions up to the blastocyst stage. This protocol, which can be adapted to observe other reporters such as Oct4-GFP or Nanog-GFP, allowed us to quantitatively analyze cleavage kinetics of cloned embryos.

  3. Status of human chromosome aberrations as a biological radiation dosimeter in the nuclear industry

    Energy Technology Data Exchange (ETDEWEB)

    Bender, M.A.

    1978-01-01

    It seems that the determination of peripheral lymphocyte chriomosome aberration levels is now firmly established as a means of biological dosimetry of great value in many phases of the nuclear industry. In the case of large external exposure it can provide valuable quantitative estimates, as well as information on dose distribution and radiation quality. In the case of routine occupational exposures the technique is more qualitative, but is of value particularly in resolving uncertainties as to whether suspected overexposures did in fact occur. Where workers accumulate burdens of internal emitters, aberration analysis provides a valuable, though at present quite qualitative indicator. In spite of the expense of cytogenetic analyses, they are of sufficient value to justify much more widespread application, particularly in high risk situations.

  4. Status of human chromosome aberrations as a biological radiation dosimeter in the nuclear industry

    International Nuclear Information System (INIS)

    Bender, M.A.

    1978-01-01

    It seems that the determination of peripheral lymphocyte chriomosome aberration levels is now firmly established as a means of biological dosimetry of great value in many phases of the nuclear industry. In the case of large external exposure it can provide valuable quantitative estimates, as well as information on dose distribution and radiation quality. In the case of routine occupational exposures the technique is more qualitative, but is of value particularly in resolving uncertainties as to whether suspected overexposures did in fact occur. Where workers accumulate burdens of internal emitters, aberration analysis provides a valuable, though at present quite qualitative indicator. In spite of the expense of cytogenetic analyses, they are of sufficient value to justify much more widespread application, particularly in high risk situations

  5. The functionally elusive RabI chromosome configuration directly regulates nuclear membrane remodeling at mitotic onset.

    Science.gov (United States)

    Fernández-Álvarez, Alfonso; Cooper, Julia Promisel

    2017-08-03

    Despite its ubiquity in interphase eukaryotic nuclei, the functional significance of the RabI configuration, in which interphase centromeres are clustered at the nuclear envelope (NE) near the centrosome and telomeres localize at the opposite end of the nucleus, has remained mysterious. In a broad variety of organisms, including Schizosaccharomyces pombe, the RabI configuration is maintained throughout mitotic interphase. The fission yeast linker of nucleoskeleton and cytoskeleton (LINC) complex mediates this centromere association. The functional significance of centromere positioning during interphase has been recently revealed using a conditionally inactivated LINC allele that maintains LINC stability but releases interphase centromere-LINC contacts. Remarkably, this interphase release abolishes mitotic spindle formation. Here, we confirm these observations using an alternative strategy to explore the role of centromere-NE association without modifying the LINC complex. We analyze spindle dynamics in cells lacking Csi1, a stabilizer of centromere-LINC associations, and Lem2, a NE protein harboring lamin interacting domains. We recapitulate these observations and their implications for the functional significance of centromere positioning for cell cycle progression in fission yeast and most likely, a wide range of eukaryotes.

  6. Notch Activation Is Associated with Tetraploidy and Enhanced Chromosomal Instability in Meningiomas

    Directory of Open Access Journals (Sweden)

    Gilson S. Baia

    2008-06-01

    Full Text Available The Notch signaling cascade is deregulated in diverse cancer types. Specific Notch function in cancer is dependent on the cellular context, the particular homologs expressed, and cross-talk with other signaling pathways. We have previously shown that components of the Notch signaling pathway are deregulated in meningiomas. How-ever, the functional consequence of abnormal Notch signaling to meningiomas is unknown. Here, we report that exogenous expression of the Notch pathway effector, HES1, is associated with tetraploid cells in meningioma cell lines. Activated Notch1 and Notch2 receptors induced endogenous HES1 expression and were associated with tetraploidy in meningiomas. Tetraploid meningioma cells exhibited nuclear features of chromosomal instability and increased frequency of nuclear atypia, such as multipolar mitotic spindles and accumulation of cells with large nuclei. FACS-sorted tetraploid cells are viable but have higher rates of spontaneous apoptosis when compared with diploid cells. We have used spectral karyotyping to show that, in contrast to diploid cells, tetraploid cells develop a higher number of both numerical and structural chromosomal abnormalities. Our findings identify a novel function for the Notch signaling pathway in generating tetraploidy and contributing to chromosomal instability. We speculate that abnormal Notch signaling pathway is an initiating genetic mechanism for meningioma and potentially promotes tumor development.

  7. Borealin/Dasra B is a cell cycle-regulated chromosomal passenger protein and its nuclear accumulation is linked to poor prognosis for human gastric cancer

    International Nuclear Information System (INIS)

    Chang, J.-L.; Chen, T.-H.; Wang, C.-F.; Chiang, Y.-H.; Huang, Y.-L.; Wong, F.-H.; Chou, C.-K.; Chen, C.-M.

    2006-01-01

    Chromosomal passenger proteins including Aurora B, Survivin, and Borealin/Dasra B, also called CDCA8/FLJ10468, are known to play crucial roles during mitosis and cell division. Inappropriate chromosomal segregation and cell division may cause auneuploidy leading to cancer. However, it is still unclear how the expression of chromosomal passenger proteins may be linked to cancer. In this study, we demonstrated that Borealin is a cell cycle-regulated gene and is upregulated at G2-M phases of the cell cycle. We showed that Borealin interacts with Survivin but not with Aurora B. The interaction domain of Survivin in Borealin was mapped to the N-terminal 92 amino-acid residues of Borealin. To examine the linkage between expression of Borealin and cancer, we performed immunohistochemistry analysis using anti-Borealin specific antibody on the paraffin-embedded gastric cancer tissues. Our results showed that Borealin expression is significantly correlated with Survivin (P = 0.003) and Ki67 (P = 0.007) in gastric cancer. Interestingly, an increased nuclear Borealin level reveals borderline association with a poor survival rate (P = 0.047). Taken together, our results demonstrated that Borealin is a cell cycle-regulated chromosomal passenger protein and its aberrant expression is linked to a poor prognosis for gastric cancer

  8. Rise, fall and resurrection of chromosome territories: a historical perspective. Part II. Fall and resurrection of chromosome territories during the 1950s to 1980s. Part III. Chromosome territories and the functional nuclear architecture: experiments and models from the 1990s to the present.

    Science.gov (United States)

    Cremer, T; Cremer, C

    2006-01-01

    Part II of this historical review on the progress of nuclear architecture studies points out why the original hypothesis of chromosome territories from Carl Rabl and Theodor Boveri (described in part I) was abandoned during the 1950s and finally proven by compelling evidence forwarded by laser-uv-microbeam studies and in situ hybridization experiments. Part II also includes a section on the development of advanced light microscopic techniques breaking the classical Abbe limit written for readers with little knowledge about the present state of the theory of light microscopic resolution. These developments have made it possible to perform 3D distance measurements between genes or other specifically stained, nuclear structures with high precision at the nanometer scale. Moreover, it has become possible to record full images from fluorescent structures and perform quantitative measurements of their shapes and volumes at a level of resolution that until recently could only be achieved by electron microscopy. In part III we review the development of experiments and models of nuclear architecture since the 1990s. Emphasis is laid on the still strongly conflicting views about the basic principles of higher order chromatin organization. A concluding section explains what needs to be done to resolve these conflicts and to come closer to the final goal of all studies of the nuclear architecture, namely to understand the implications of nuclear architecture for nuclear functions.

  9. Analysis of chromosome translocation in the residents of Namie Town after the accident of Fukushima Daiichi Nuclear Power Plant

    International Nuclear Information System (INIS)

    Yoshida, Mitsuaki A.; Nakata, Akifumi; Miura, Tomisato; Nishimura, Miya; Takamagi, Shizuka; Kasai, Kosuke; Konno, Norio; Yoshida, Ryoko; Sekine, Shunji

    2014-01-01

    The dose estimation by behavior survey of the residents carried out by Fukushima Prefecture after the accident reported that there are no residents who were exposed by over 1 mSv radiation. However, a lot of the parents are worrying about the health condition of their children in future. Our Hirosaki University accepted the request of the local government of this Namie-Town in Fukushima which wants to know whether children were exposed by radiological substances or not and started the inspection about the contamination and exposure level and dose estimation at an accident using chromosomal translocation analysis for 855 out of 3700 children whose age was under 18 years old at the time of accident. In order to estimate radiation dose using chromosome aberration in the accidents, there are four kinds of cytogenetic method; dicentric assay, a translocation assay, the PCC-ring assay and micronucleus test. A dicentric assay is used for the dose estimation in acute and external exposure cases, the chromosomal translocation method for dose assessment in chronic and old exposure and the PCC method for high dose exposure, respectively. In the case of the residents in Namie-Town, since about one year and ten months had already passed after the accident when implementation of this inspection was determined, the chromosomal translocation method was applied for the dose estimation of the initial exposure level. The main purpose of this translocation analysis using their own cells is to take away affairs of the residents including parents and children and also to reduce the uneasiness which is not wiped away by the health check due to a behavioral survey. In this inspection, after the contents and process of this analysis were explained in the Tsushima, Namie-Town temporarily constructed clinic, 3∼4 ml of whole 5 blood were taken from each children whose parents agreed with this analysis. The lymphocytic cells are isolated from the whole blood using CPT (Cell Preparation Tube

  10. A novel chromosome region maintenance 1-independent nuclear export signal of the large form of hepatitis delta antigen that is required for the viral assembly.

    Science.gov (United States)

    Lee, C H; Chang, S C; Wu, C H; Chang, M F

    2001-03-16

    Hepatitis delta virus (HDV) is a satellite virus of hepatitis B virus, as it requires hepatitis B virus for virion production and transmission. We have previously demonstrated that sequences within the C-terminal 19-amino acid domain flanking the isoprenylation motif of the large hepatitis delta antigen (HDAg-L) are important for virion assembly. In this study, site-directed mutagenesis and immunofluorescence staining demonstrated that in the absence of hepatitis B virus surface antigen (HBsAg), the wild-type HDAg-L was localized in the nuclei of transfected COS7 cells. Nevertheless, in the presence of HBsAg, the HDAg-L became both nuclei- and cytoplasm-distributed in about half of the cells. An HDAg-L mutant with a substitution of Pro-205 to alanine could neither form HDV-like particles nor shift the subcellular localization in the presence of HBsAg. In addition, nuclear trafficking of HDAg-L in heterokaryons indicated that HDAg-L is a nucleocytoplasmic shuttling protein. A proline-rich HDAg peptide spanning amino acid residues 198 to 210, designated NES(HDAg-L), can function as a nuclear export signal (NES) in Xenopus oocytes. Pro-205 is critical for the NES function. Furthermore, assembly of HDV is insensitive to leptomycin B, indicating that the NES(HDAg-L) directs nuclear export of HDAg-L to the cytoplasm via a chromosome region maintenance 1-independent pathway.

  11. The nuclear protein encoded by the Drosophila neurogenic gene mastermind is widely expressed and associates with specific chromosomal regions

    Energy Technology Data Exchange (ETDEWEB)

    Bettler, D.; Pearson, S.; Yedvobnick, B. [Emory Univ., Atlanta, GA (United States)

    1996-06-01

    The Drosophila neurogenic loci encode a diverse group of proteins that comprise an inhibitory signal transduction pathway. The pathway is used throughout development in numerous contexts. We have examined the distribution of the neurogenic locus mastermind protein (Mam). Mam is expressed through all germlayers during early embryogenesis, including ectodermal precursors to both neuroblasts and epidermoblasts. Mam is subsequently down-regulated within the nervous system and then reexpressed. It persists in the nervous system through late embryogenesis and postembryonically. Mam is ubiquitously expressed in wing and leg imaginal discs and is not down-regulated in sensory organ precursor cells of the wing margin or notum. In the eye disc, Mam shows most prominent expression posterior to the morphogenetic furrow. Expression of the protein during oogenesis appears limited to follicle cells. Immunohistochemical detection of Mam on polytene chromosomes revealed binding at >100 sites. Chromosome colocalization studies with RNA polymerase and the groucho corepressor protein implicate Mam in transcriptional regulation. 94 refs., 8 figs., 1 tab.

  12. Leukemia in the proximity of a German boiling water nuclear reactor: Evidence of population exposure by chromosome studies and environmental radioactivity

    International Nuclear Information System (INIS)

    Dannheim, B.; Heimers, A.; Oberheitmann, B.; Schmitz-Feuerhake, I.; Schroeder, H.; Ziggel, H.

    1997-01-01

    The detection of an exceptional elevation of leukemia in children appearing 5 years after the start-up of the nuclear power plant Kruemmel in 1983, accompanied by a significant increase of leukemia cases in adults gave rise for investigations of radiation exposures of the population living near to the plant. The rate of dicentric chromosomes in peripheral blood lymphocytes of 7 parents of leukemia children and 14 other inhabitants in the proximity of the plant was significantly elevated and showed ongoing exposures over the years of operation. This finding gives rise to the hypothesis that chronic leakages by the reactor had occurred. This assumption is supported by the identification of artificial radioactivity in air, rain water, soil, and vegetation registered by the regular environmental monitoring programme of the nuclear power plant. Calculations of the corresponding source terms show that the originating emissions must have been well above authorized annual limits. The bone marrow dose is supposed to be originated mainly by incorporating of bone-seeking β- and α-emitters. (author)

  13. Rac-mediated Stimulation of Phospholipase Cγ2 Amplifies B Cell Receptor-induced Calcium Signaling*♦

    Science.gov (United States)

    Walliser, Claudia; Tron, Kyrylo; Clauss, Karen; Gutman, Orit; Kobitski, Andrei Yu.; Retlich, Michael; Schade, Anja; Röcker, Carlheinz; Henis, Yoav I.; Nienhaus, G. Ulrich; Gierschik, Peter

    2015-01-01

    The Rho GTPase Rac is crucially involved in controlling multiple B cell functions, including those regulated by the B cell receptor (BCR) through increased cytosolic Ca2+. The underlying molecular mechanisms and their relevance to the functions of intact B cells have thus far remained unknown. We have previously shown that the activity of phospholipase Cγ2 (PLCγ2), a key constituent of the BCR signalosome, is stimulated by activated Rac through direct protein-protein interaction. Here, we use a Rac-resistant mutant of PLCγ2 to functionally reconstitute cultured PLCγ2-deficient DT40 B cells and to examine the effects of the Rac-PLCγ2 interaction on BCR-mediated changes of intracellular Ca2+ and regulation of Ca2+-regulated and nuclear-factor-of-activated-T-cell-regulated gene transcription at the level of single, intact B cells. The results show that the functional Rac-PLCγ2 interaction causes marked increases in the following: (i) sensitivity of B cells to BCR ligation; (ii) BCR-mediated Ca2+ release from intracellular stores; (iii) Ca2+ entry from the extracellular compartment; and (iv) nuclear translocation of the Ca2+-regulated nuclear factor of activated T cells. Hence, Rac-mediated stimulation of PLCγ2 activity serves to amplify B cell receptor-induced Ca2+ signaling. PMID:25903139

  14. 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)

  15. Three-dimensional super-resolution microscopy of the inactive X chromosome territory reveals a collapse of its active nuclear compartment harboring distinct Xist RNA foci.

    Science.gov (United States)

    Smeets, Daniel; Markaki, Yolanda; Schmid, Volker J; Kraus, Felix; Tattermusch, Anna; Cerase, Andrea; Sterr, Michael; Fiedler, Susanne; Demmerle, Justin; Popken, Jens; Leonhardt, Heinrich; Brockdorff, Neil; Cremer, Thomas; Schermelleh, Lothar; Cremer, Marion

    2014-01-01

    A Xist RNA decorated Barr body is the structural hallmark of the compacted inactive X territory in female mammals. Using super-resolution three-dimensional structured illumination microscopy (3D-SIM) and quantitative image analysis, we compared its ultrastructure with active chromosome territories (CTs) in human and mouse somatic cells, and explored the spatio-temporal process of Barr body formation at onset of inactivation in early differentiating mouse embryonic stem cells (ESCs). We demonstrate that all CTs are composed of structurally linked chromatin domain clusters (CDCs). In active CTs the periphery of CDCs harbors low-density chromatin enriched with transcriptionally competent markers, called the perichromatin region (PR). The PR borders on a contiguous channel system, the interchromatin compartment (IC), which starts at nuclear pores and pervades CTs. We propose that the PR and macromolecular complexes in IC channels together form the transcriptionally permissive active nuclear compartment (ANC). The Barr body differs from active CTs by a partially collapsed ANC with CDCs coming significantly closer together, although a rudimentary IC channel system connected to nuclear pores is maintained. Distinct Xist RNA foci, closely adjacent to the nuclear matrix scaffold attachment factor-A (SAF-A) localize throughout Xi along the rudimentary ANC. In early differentiating ESCs initial Xist RNA spreading precedes Barr body formation, which occurs concurrent with the subsequent exclusion of RNA polymerase II (RNAP II). Induction of a transgenic autosomal Xist RNA in a male ESC triggers the formation of an 'autosomal Barr body' with less compacted chromatin and incomplete RNAP II exclusion. 3D-SIM provides experimental evidence for profound differences between the functional architecture of transcriptionally active CTs and the Barr body. Basic structural features of CT organization such as CDCs and IC channels are however still recognized, arguing against a uniform

  16. 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

  17. 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

  18. A map of nuclear matrix attachment regions within the breast cancer loss-of-heterozygosity region on human chromosome 16q22.1

    DEFF Research Database (Denmark)

    Shaposhnikov, Sergey A.; Akopov, Sergey B.; Chernov, Igor P.

    2007-01-01

    There is abundant evidence that the DNA in eukaryotic cells is organized into loop domains that represent basic structural and functional units of chromatin packaging. To explore the DNA domain organization of the breast cancer loss-of-heterozygosity region on human chromosome 16q22.1, we have...

  19. Modelling chromosomal aberration induction by ionising radiation: The influence of interphase chromosome architecture

    Science.gov (United States)

    Ottolenghi, A.; Ballarini, F.; Biaggi, M.

    Several advances have been achieved in the knowledge of nuclear architecture and functions during the last decade, thus allowing the identification of interphase chromosome territories and sub-chromosomal domains (e.g. arm and band domains). This is an important step in the study of radiation-induced chromosome aberrations; indeed, the coupling between track-structure simulations and reliable descriptions of the geometrical properties of the target is one of the main tasks in modelling aberration induction by radiation, since it allows one to clarify the role of the initial positioning of two DNA lesions in determining their interaction probability. In the present paper, the main recent findings on nuclear and chromosomal architecture are summarised. A few examples of models based on different descriptions of interphase chromosome organisation (random-walk models, domain models and static models) are presented, focussing on how the approach adopted in modelling the target nuclei and chromosomes can influence the simulation of chromosomal aberration yields. Each model is discussed by taking into account available experimental data on chromosome aberration induction and/or interphase chromatin organisation. Preliminary results from a mechanistic model based on a coupling between radiation track-structure features and explicitly-modelled, non-overlapping chromosome territories are presented.

  20. The Emerging Role of the Cytoskeleton in Chromosome Dynamics

    Directory of Open Access Journals (Sweden)

    Maya Spichal

    2017-05-01

    Full Text Available Chromosomes underlie a dynamic organization that fulfills functional roles in processes like transcription, DNA repair, nuclear envelope stability, and cell division. Chromosome dynamics depend on chromosome structure and cannot freely diffuse. Furthermore, chromosomes interact closely with their surrounding nuclear environment, which further constrains chromosome dynamics. Recently, several studies enlighten that cytoskeletal proteins regulate dynamic chromosome organization. Cytoskeletal polymers that include actin filaments, microtubules and intermediate filaments can connect to the nuclear envelope via Linker of the Nucleoskeleton and Cytoskeleton (LINC complexes and transfer forces onto chromosomes inside the nucleus. Monomers of these cytoplasmic polymers and related proteins can also enter the nucleus and play different roles in the interior of the nucleus than they do in the cytoplasm. Nuclear cytoskeletal proteins can act as chromatin remodelers alone or in complexes with other nuclear proteins. They can also act as transcription factors. Many of these mechanisms have been conserved during evolution, indicating that the cytoskeletal regulation of chromosome dynamics is an essential process. In this review, we discuss the different influences of cytoskeletal proteins on chromosome dynamics by focusing on the well-studied model organism budding yeast.

  1. Molecular karyotyping of single sperm with nuclear vacuoles identifies more chromosomal abnormalities in patients with testiculopathy than fertile controls: implications for ICSI.

    Science.gov (United States)

    Garolla, Andrea; Sartini, Barbara; Cosci, Ilaria; Pizzol, Damiano; Ghezzi, Marco; Bertoldo, Alessandro; Menegazzo, Massimo; Speltra, Elena; Ferlin, Alberto; Foresta, Carlo

    2015-11-01

    Is there a difference between molecular karyotype of single sperm selected by high-magnification microscopy from infertile patients with testicular damage and from proven fertile controls? The molecular karyotype of single sperm from patients with testiculopathy had a significantly higher percentage of chromosomal alterations than fertile controls. Infertile patients with testicular impairment have many sperm with aneuploidies and/or increased structural chromosome alterations. In these patients, sperm use by ICSI has poor outcome and raises concerns about the possible impact on pregnancy loss and transmission of genes abnormalities in offspring. High-magnification microscopy has been recently introduced to select morphologically better sperm aimed at improving ICSI outcome. However, there are no studies evaluating the molecular karyotype of sperm selected by this method. Three consecutive infertile patients with oligozoospermia due to testicular damage and three age-matched proven fertile men attending a tertiary care center, were enrolled in the study from September to November 2014. Inclusion criteria of patients were age ≥30 ≤35 years, at least 2 years of infertility, oligozoospermia (sperm count below 10 million), reduced testicular volumes high FSH plasma levels and absence of altered karyotype, Y chromosome microdeletions, cystic fibrosis transmembrane conductance regulator gene mutations, sperm infections, cigarette smoking, varicocele, obesity. Participants were evaluated for sperm parameters, sex hormones and testicular color-doppler ultrasound. From each semen sample, 20 sperm with large vacuoles (LVs), 20 with small vacuoles (SVs) and 20 with no vacuoles (NVs) were retrieved individually by a micromanipulator system. Each cell was further analyzed by whole genome amplification and array comparative genomic hybridization (aCGH). The aCGH allowed us to detect chromosomal aneuploidies, unbalanced translocations and complex abnormalities. Sperm selected

  2. Know Your Chromosomes

    Indian Academy of Sciences (India)

    other human chromosomes. The presence of abnormal chromosomal number described in general as aneuploidy, here trisomy, is observed in certain other syndromes too. Trisomies of chromosome 18, 13,22,8,9 and X are known. Children with these 'numerical' anomalies have severe and complex malformations. Mental ...

  3. 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

  4. ZEBRAFISH CHROMOSOME-BANDING

    NARCIS (Netherlands)

    PIJNACKER, LP; FERWERDA, MA

    1995-01-01

    Banding techniques were carried out on metaphase chromosomes of zebrafish (Danio rerio) embryos. The karyotypes with the longest chromosomes consist of 12 metacentrics, 26 submetacentrics, and 12 subtelocentrics (2n = 50). All centromeres are C-band positive. Eight chromosomes have a pericentric

  5. The potential of 3D-FISH and super-resolution structured illumination microscopy for studies of 3D nuclear architecture: 3D structured illumination microscopy of defined chromosomal structures visualized by 3D (immuno)-FISH opens new perspectives for studies of nuclear architecture.

    Science.gov (United States)

    Markaki, Yolanda; Smeets, Daniel; Fiedler, Susanne; Schmid, Volker J; Schermelleh, Lothar; Cremer, Thomas; Cremer, Marion

    2012-05-01

    Three-dimensional structured illumination microscopy (3D-SIM) has opened up new possibilities to study nuclear architecture at the ultrastructural level down to the ~100 nm range. We present first results and assess the potential using 3D-SIM in combination with 3D fluorescence in situ hybridization (3D-FISH) for the topographical analysis of defined nuclear targets. Our study also deals with the concern that artifacts produced by FISH may counteract the gain in resolution. We address the topography of DAPI-stained DNA in nuclei before and after 3D-FISH, nuclear pores and the lamina, chromosome territories, chromatin domains, and individual gene loci. We also look at the replication patterns of chromocenters and the topographical relationship of Xist-RNA within the inactive X-territory. These examples demonstrate that an appropriately adapted 3D-FISH/3D-SIM approach preserves key characteristics of the nuclear ultrastructure and that the gain in information obtained by 3D-SIM yields new insights into the functional nuclear organization. Copyright © 2012 WILEY Periodicals, Inc.

  6. Structure of the human chromosome interaction network.

    Directory of Open Access Journals (Sweden)

    Sergio Sarnataro

    Full Text Available New Hi-C technologies have revealed that chromosomes have a complex network of spatial contacts in the cell nucleus of higher organisms, whose organisation is only partially understood. Here, we investigate the structure of such a network in human GM12878 cells, to derive a large scale picture of nuclear architecture. We find that the intensity of intra-chromosomal interactions is power-law distributed. Inter-chromosomal interactions are two orders of magnitude weaker and exponentially distributed, yet they are not randomly arranged along the genomic sequence. Intra-chromosomal contacts broadly occur between epigenomically homologous regions, whereas inter-chromosomal contacts are especially associated with regions rich in highly expressed genes. Overall, genomic contacts in the nucleus appear to be structured as a network of networks where a set of strongly individual chromosomal units, as envisaged in the 'chromosomal territory' scenario derived from microscopy, interact with each other via on average weaker, yet far from random and functionally important interactions.

  7. Chromosome aberrations in Japanese fishermen exposed to fallout radiation 420-1200 km distant from the nuclear explosion test site at Bikini Atoll: report 60 years after the incident

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Kimio [Hiroshima University, Research Institute for Radiation Biology and Medicine, Hiroshima City, Hiroshima (Japan); Institute for Environmental Sciences, Kakimita, Aomori (Japan); Ohtaki, Megu; Hoshi, Masaharu [Hiroshima University, Research Institute for Radiation Biology and Medicine, Hiroshima City, Hiroshima (Japan)

    2016-08-15

    During the period from March to May, 1954, the USA conducted six nuclear weapon tests at the ''Bravo'' detonation sites at the Bikini and Enewetak Atolls, Marshall Islands. At that time, the crew of tuna fishing boats and cargo ships that were operating approximately 150-1200 km away from the test sites were exposed to radioactive fallout. The crew of the fishing boats and those on cargo ships except the ''5th Fukuryu-maru'' did not undergo any health examinations at the time of the incident. In the present study, chromosome aberrations in peripheral blood lymphocytes were examined in detail by the G-banding method in 17 crew members from 8 fishing boats and 2 from one cargo ship, 60 years after the tests. None of the subjects examined had suffered from cancer. The percentages of both stable-type aberrations such as translocation, inversion and deletion, and unstable-type aberrations such as dicentric and centric ring in the study group were significantly higher (1.4- and 2.3-fold, respectively) than those in nine age-matched controls. In the exposed and control groups, the percentages of stable-type aberrations were 3.35 % and 2.45 %, respectively, and the numbers of dicentric and centric ring chromosomes per 100 cells were 0.35 and 0.15, respectively. Small clones were observed in three members of the exposed group. These results suggest that the crews were exposed to slightly higher levels of fallout than had hitherto been assumed. (orig.)

  8. Chromosome aberrations in Japanese fishermen exposed to fallout radiation 420-1200 km distant from the nuclear explosion test site at Bikini Atoll: report 60 years after the incident.

    Science.gov (United States)

    Tanaka, Kimio; Ohtaki, Megu; Hoshi, Masaharu

    2016-08-01

    During the period from March to May, 1954, the USA conducted six nuclear weapon tests at the "Bravo" detonation sites at the Bikini and Enewetak Atolls, Marshall Islands. At that time, the crew of tuna fishing boats and cargo ships that were operating approximately 150-1200 km away from the test sites were exposed to radioactive fallout. The crew of the fishing boats and those on cargo ships except the "5th Fukuryu-maru" did not undergo any health examinations at the time of the incident. In the present study, chromosome aberrations in peripheral blood lymphocytes were examined in detail by the G-banding method in 17 crew members from 8 fishing boats and 2 from one cargo ship, 60 years after the tests. None of the subjects examined had suffered from cancer. The percentages of both stable-type aberrations such as translocation, inversion and deletion, and unstable-type aberrations such as dicentric and centric ring in the study group were significantly higher (1.4- and 2.3-fold, respectively) than those in nine age-matched controls. In the exposed and control groups, the percentages of stable-type aberrations were 3.35 % and 2.45 %, respectively, and the numbers of dicentric and centric ring chromosomes per 100 cells were 0.35 and 0.15, respectively. Small clones were observed in three members of the exposed group. These results suggest that the crews were exposed to slightly higher levels of fallout than had hitherto been assumed.

  9. Fetal chromosome analysis: screening for chromosome disease?

    DEFF Research Database (Denmark)

    Philip, J; Tabor, Ann; Bang, J

    1983-01-01

    with women without elevated risk. Spontaneous abortion rate and prematurity rate did not differ from rates expected without amniocentesis. It is concluded that current indications may be characterized as a mixture of evident high risk factors and factors with only a minor influence on risk. Indications......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...

  10. Transcript variations, phylogenetic tree and chromosomal ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Genetics; Volume 96; Issue 1. Transcript variations, phylogenetic tree and chromosomal localization of porcine aryl hydrocarbon receptor (AhR) and AhR nuclear translocator (ARNT) genes. AGNIESZKA SADOWSKA LUKASZ PAUKSZTO ANNA NYNCA IZABELA SZCZERBAL KARINA ...

  11. 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

  12. Changes in chromosome structure, mitotic activity and nuclear DNA content from cells of Allium Test induced by bark water extract of Uncaria tomentosa (Willd.) DC.

    Science.gov (United States)

    Kuraś, Mieczysław; Nowakowska, Julita; Sliwińska, Elwira; Pilarski, Radosław; Ilasz, Renata; Tykarska, Teresa; Zobel, Alicja; Gulewicz, Krzysztof

    2006-09-19

    The influence of water extract of Uncaria tomentosa (Willd.) DC bark on the meristematic cells of the root tips of Allium cepa L., e.g. cells of Allium Test, was investigated. The experiment was carried out in two variants: (1) continuous incubation at different concentrations (2, 4, 8 and 16 mg/ml) of the extract for 3, 6, 12, 24, 48 and 72h; and (2) 24-h incubation in three concentrations of the extract (4, 8 or 16 mg/ml), followed by post-incubation in distilled water for 3, 6, 12, 24 and 48h. During the continuous incubation, the mitotic activity was reduced (2 and 4 mg/ml) or totally inhibited (8 and 16 mg/ml), depending on the concentration of the extract. All the concentrations resulted in gradual reduction of the mitotic activity. In the concentration of 2 mg/ml, the mitotic activity reached its lowest value after 12h (2 mg/ml) and after 24h in 4 mg/ml, followed by spontaneous intensification of divisions during further incubation. Instead, in higher concentrations of the extracts (8 and 16 mg/ml), the mitotic activity was totally inhibited within 24h and did not resume even after 72h. Incubation caused changes in the phase index, mainly as an increase in the number of prophases. After 24h of incubation, in all phases, condensation and contraction of chromosomes were observed. During post-incubation, divisions resumed in all concentrations, reaching even higher values than the control. Cytometric analysis showed that the extract caused inhibition of the cell cycle at the border between gap(2) and beginning of mitosis (G(2)/M).

  13. Analysis of plant meiotic chromosomes by chromosome painting.

    Science.gov (United States)

    Lysak, Martin A; Mandáková, Terezie

    2013-01-01

    Chromosome painting (CP) refers to visualization of large chromosome regions, entire chromosome arms, or entire chromosomes via fluorescence in situ hybridization (FISH). For CP in plants, contigs of chromosome-specific bacterial artificial chromosomes (BAC) from the target species or from a closely related species (comparative chromosome painting, CCP) are typically applied as painting probes. Extended pachytene chromosomes provide the highest resolution of CP in plants. CP enables identification and tracing of particular chromosome regions and/or entire chromosomes throughout all meiotic stages as well as corresponding chromosome territories in premeiotic interphase nuclei. Meiotic pairing and structural chromosome rearrangements (typically inversions and translocations) can be identified by CP. Here, we describe step-by-step protocols of CP and CCP in plant species including chromosome preparation, BAC DNA labeling, and multicolor FISH.

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

    Indian Academy of Sciences (India)

    2010-09-06

    Sep 6, 2010 ... [Traut W. 2010 New Y chromosomes and early stages of sex chromosome differentiation: sex determination in Megaselia. J. Genet. 89,. 307–313]. Introduction. Sex-chromosome ..... age group III-Y chromosomes were successful while in well- aerated population cages, linkage group I-Y chromosomes.

  15. Ciliary neurotrophic factor mediates dopamine D2 receptor-induced CNS neurogenesis in adult mice.

    Science.gov (United States)

    Yang, Peng; Arnold, Sheila A; Habas, Agata; Hetman, Michal; Hagg, Theo

    2008-02-27

    Neurogenesis continues in the adult forebrain subventricular zone (SVZ) and the dentate gyrus of the hippocampal formation. Degeneration of dopaminergic projections in Parkinson's disease and animals reduces, whereas ciliary neurotrophic factor (CNTF) promotes, neurogenesis. We tested whether the dopaminergic system promotes neurogenesis through CNTF. Astrocytes of the SVZ and dentate gyrus expressed CNTF and were close to dopaminergic terminals. Dopaminergic denervation in adult mice reduced CNTF mRNA by approximately 60%, whereas systemic treatment with the D2 agonist quinpirole increased CNTF mRNA in the SVZ and hippocampal formation, and in cultured astrocytes by 1.5-5 fold. The effect of quinpirole in vitro was blocked by the D2 antagonist eticlopride and did not cause astroglial proliferation or hypertrophy. Systemic quinpirole injections increased proliferation in wild-type mice by approximately 25-75% but not in CNTF-/- littermates or in the SVZ of mice infused with CNTF antibodies. Quinpirole increased the number of neuroblasts in wild-type but not in CNTF-/- littermates. Neurogenesis was reduced by approximately 20% in CNTF-/- mice, confirming the endogenous role of CNTF. Nigrostriatal denervation did not affect SVZ proliferation in CNTF-/- mice, suggesting that the dopaminergic innervation normally regulates neurogenesis through CNTF. Quinpirole acted on postsynaptic receptors as it reversed the reduced proliferation seen after dopaminergic denervation in wild-type mice. Thus, CNTF mediates dopaminergic innervation- and D2 receptor-induced neurogenesis in the adult forebrain. Because CNTF is predominantly expressed in the nervous system, this mechanism and the ability to pharmacologically modulate it have implications for Parkinson's disease and cell-replacement therapies for other disorders.

  16. Sex Chromosome Drive

    OpenAIRE

    Helleu, Quentin; Gérard, Pierre R.; Montchamp-Moreau, Catherine

    2015-01-01

    Sex chromosome drivers are selfish elements that subvert Mendel's first law of segregation and therefore are overrepresented among the products of meiosis. The sex-biased progeny produced then fuels an extended genetic conflict between the driver and the rest of the genome. Many examples of sex chromosome drive are known, but the occurrence of this phenomenon is probably largely underestimated because of the difficulty to detect it. Remarkably, nearly all sex chromosome drivers are found in t...

  17. Chromosomal Evolution in Chiroptera.

    Science.gov (United States)

    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.

  18. Chromosomal Evolution in Chiroptera

    Directory of Open Access Journals (Sweden)

    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.

  19. Ring chromosome 13

    DEFF Research Database (Denmark)

    Brandt, C A; Hertz, Jens Michael; Petersen, M B

    1992-01-01

    A stillborn male child with anencephaly and multiple malformations was found to have the karyotype 46,XY,r(13) (p11q21.1). The breakpoint at 13q21.1, determined by high resolution banding, is the most proximal breakpoint ever reported in patients with ring chromosome 13. In situ hybridisation...... with the probe L1.26 confirmed the derivation from chromosome 13 and DNA polymorphism analysis showed maternal origin of the ring chromosome. Our results, together with a review of previous reports of cases with ring chromosome 13 with identified breakpoints, could neither support the theory of distinct clinical...

  20. Heterogeneous nuclear ribonucleoproteins H, H', and F are members of a ubiquitously expressed subfamily of related but distinct proteins encoded by genes mapping to different chromosomes

    DEFF Research Database (Denmark)

    Honoré, B; Rasmussen, H H; Vorum, H

    1995-01-01

    and keratinocytes. In normal human keratinocytes, the expression level of H was unaffected by treatment with several substances tested including two second messengers and seven cytokines. Likewise the expression level of F was independent of these substances, although it was strikingly down-regulated by long term......Molecular cDNA cloning, two-dimensional gel immunoblotting, and amino acid microsequencing identified three sequence-unique and distinct proteins that constitute a subfamily of ubiquitously expressed heterogeneous nuclear ribonucleoproteins corresponding to hnRNPs H, H', and F. These proteins share...... for ribohomopolymer binding studies. Each qRRM repeat bound poly(rG), while only the NH2-terminal qRRM bound poly(rC) and poly(rU). None of the repeats bound detectable amounts of poly(rA). The expression levels of hnRNPs H and F were differentially regulated in pairs of normal and transformed fibroblasts...

  1. Phase separation of a Lennard-Jones fluid interacting with a long, condensed polymer chain: implications for the nuclear body formation near chromosomes.

    Science.gov (United States)

    Oh, Inrok; Choi, Saehyun; Jung, YounJoon; Kim, Jun Soo

    2015-08-28

    Phase separation in a biological cell nucleus occurs in a heterogeneous environment filled with a high density of chromatins and thus it is inevitably influenced by interactions with chromatins. As a model system of nuclear body formation in a cell nucleus filled with chromatins, we simulate the phase separation of a low-density Lennard-Jones (LJ) fluid interacting with a long, condensed polymer chain. The influence of the density variation of LJ particles above and below the phase boundary and the role of attractive interactions between LJ particles and polymer segments are investigated at a fixed value of strong self-interaction between LJ particles. For a density of LJ particles above the phase boundary, phase separation occurs and a dense domain of LJ particles forms irrespective of interactions with the condensed polymer chain whereas its localization relative to the polymer chain is determined by the LJ-polymer attraction strength. Especially, in the case of moderately weak attractions, the domain forms separately from the polymer chain and subsequently associates with the polymer chain. When the density is below the phase boundary, however, the formation of a dense domain is possible only when the LJ-polymer attraction is strong enough, for which the domain grows in direct contact with the interacting polymer chain. In this work, different growth behaviors of LJ particles result from the differences in the density of LJ particles and in the LJ-polymer interaction, and this work suggests that the distinct formation of activity-dependent and activity-independent nuclear bodies (NBs) in a cell nucleus may originate from the differences in the concentrations of body-specific NB components and in their interaction with chromatins.

  2. Novel insights into mitotic chromosome condensation [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Ewa Piskadlo

    2016-07-01

    Full Text Available The fidelity of mitosis is essential for life, and successful completion of this process relies on drastic changes in chromosome organization at the onset of nuclear division. The mechanisms that govern chromosome compaction at every cell division cycle are still far from full comprehension, yet recent studies provide novel insights into this problem, challenging classical views on mitotic chromosome assembly. Here, we briefly introduce various models for chromosome assembly and known factors involved in the condensation process (e.g. condensin complexes and topoisomerase II. We will then focus on a few selected studies that have recently brought novel insights into the mysterious way chromosomes are condensed during nuclear division.

  3. Chromosomes of Protists: The crucible of evolution.

    Science.gov (United States)

    Soyer-Gobillard, Marie-Odile; Dolan, Michael F

    2015-12-01

    As early as 1925, the great protozoologist Edouard Chatton classified microorganisms into two categories, the prokaryotic and the eukaryotic microbes, based on light microscopical observation of their nuclear organization. Now, by means of transmission electron microscopy, we know that prokaryotic microbes are characterized by the absence of nuclear envelope surrounding the bacterial chromosome, which is more or less condensed and whose chromatin is deprived of histone proteins but presents specific basic proteins. Eukaryotic microbes, the protists, have nuclei surrounded by a nuclear envelope and have chromosomes more or less condensed, with chromatin-containing histone proteins organized into nucleosomes. The extraordinary diversity of mitotic systems presented by the 36 phyla of protists (according to Margulis et al., Handbook of Protoctista, 1990) is in contrast to the relative homogeneity of their chromosome structure and chromatin components. Dinoflagellates are the exception to this pattern. The phylum is composed of around 2000 species, and characterized by unique features including their nucleus (dinokaryon), dinomitosis, chromosome organization and chromatin composition. Although their DNA synthesis is typically eukaryotic, dinoflagellates are the only eukaryotes in which the chromatin, organized into quasi-permanently condensed chromosomes, is in some species devoid of histones and nucleosomes. In these cases, their chromatin contains specific DNA-binding basic proteins. The permanent compaction of their chromosomes throughout the cell cycle raises the question of the modalities of their division and their transcription. Successful in vitro reconstitution of nucleosomes using dinoflagellate DNA and heterologous corn histones raises questions about dinoflagellate evolution and phylogeny. [Int Microbiol 18(4):209-216 (2015)]. Copyright© by the Spanish Society for Microbiology and Institute for Catalan Studies.

  4. Chromosome painting reveals asynaptic full alignment of homologs and HIM-8-dependent remodeling of X chromosome territories during Caenorhabditis elegans meiosis.

    Directory of Open Access Journals (Sweden)

    Kentaro Nabeshima

    2011-08-01

    Full Text Available During early meiotic prophase, a nucleus-wide reorganization leads to sorting of chromosomes into homologous pairs and to establishing associations between homologous chromosomes along their entire lengths. Here, we investigate global features of chromosome organization during this process, using a chromosome painting method in whole-mount Caenorhabditis elegans gonads that enables visualization of whole chromosomes along their entire lengths in the context of preserved 3D nuclear architecture. First, we show that neither spatial proximity of premeiotic chromosome territories nor chromosome-specific timing is a major factor driving homolog pairing. Second, we show that synaptonemal complex-independent associations can support full lengthwise juxtaposition of homologous chromosomes. Third, we reveal a prominent elongation of chromosome territories during meiotic prophase that initiates prior to homolog association and alignment. Mutant analysis indicates that chromosome movement mediated by association of chromosome pairing centers (PCs with mobile patches of the nuclear envelope (NE-spanning SUN-1/ZYG-12 protein complexes is not the primary driver of territory elongation. Moreover, we identify new roles for the X chromosome PC (X-PC and X-PC binding protein HIM-8 in promoting elongation of X chromosome territories, separable from their role(s in mediating local stabilization of pairing and association of X chromosomes with mobile SUN-1/ZYG-12 patches. Further, we present evidence that HIM-8 functions both at and outside of PCs to mediate chromosome territory elongation. These and other data support a model in which synapsis-independent elongation of chromosome territories, driven by PC binding proteins, enables lengthwise juxtaposition of chromosomes, thereby facilitating assessment of their suitability as potential pairing partners.

  5. Inter-chromosomal gene regulation in the mammalian cell nucleus.

    Science.gov (United States)

    de Laat, Wouter; Grosveld, Frank

    2007-10-01

    Cellular phenotypes can critically rely on mono-allelic gene expression. Recent studies suggest that in mammalian cells inter-chromosomal DNA interactions may mediate the decision which allele to activate and which to silence. Here, these findings are discussed in the context of knowledge on gene competition, chromatin dynamics, and nuclear organization. We argue that data obtained by 4C technology strongly support the idea that chromatin folds according to self-organizing principles. In this concept, the nuclear positioning of a given locus is probabilistic as it also depends on the properties of neighbouring DNA segments and, by extrapolation, the whole chromosome. The linear distribution of repetitive DNA sequences and of active and inactive DNA regions is important for the folding and relative positioning of chromosomes. This stochastic concept of nuclear organization predicts that tissue-specific interactions between two selected loci present on different chromosomes will be rare.

  6. Chromosome Evolution in Connection with Repetitive Sequences and Epigenetics in Plants

    OpenAIRE

    Li, Shu-Fen; Su, Ting; Cheng, Guang-Qian; Wang, Bing-Xiao; Li, Xu; Deng, Chuan-Liang; Gao, Wu-Jun

    2017-01-01

    Chromosome evolution is a fundamental aspect of evolutionary biology. The evolution of chromosome size, structure and shape, number, and the change in DNA composition suggest the high plasticity of nuclear genomes at the chromosomal level. Repetitive DNA sequences, which represent a conspicuous fraction of every eukaryotic genome, particularly in plants, are found to be tightly linked with plant chromosome evolution. Different classes of repetitive sequences have distinct distribution pattern...

  7. Polyphyletic origin of the genus Physarum (Physarales, Myxomycetes revealed by nuclear rDNA mini-chromosome analysis and group I intron synapomorphy

    Directory of Open Access Journals (Sweden)

    Nandipati Satish CR

    2012-08-01

    Full Text Available Abstract Background Physarales represents the largest taxonomic order among the plasmodial slime molds (myxomycetes. Physarales is of particular interest since the two best-studied myxomycete species, Physarum polycephalum and Didymium iridis, belong to this order and are currently subjected to whole genome and transcriptome analyses. Here we report molecular phylogeny based on ribosomal DNA (rDNA sequences that includes 57 Physarales isolates. Results The Physarales nuclear rDNA sequences were found to be loaded with 222 autocatalytic group I introns, which may complicate correct alignments and subsequent phylogenetic tree constructions. Phylogenetic analysis of rDNA sequences depleted of introns confirmed monophyly of the Physarales families Didymiaceae and Physaraceae. Whereas good correlation was noted between phylogeny and taxonomy among the Didymiaceae isolates, significant deviations were seen in Physaraceae. The largest genus, Physarum, was found to be polyphyletic consisting of at least three well supported clades. A synapomorphy, located at the highly conserved G-binding site of L2449 group I intron ribozymes further supported the Physarum clades. Conclusions Our results provide molecular relationship of Physarales genera, species, and isolates. This information is important in further interpretations of comparative genomics nd transcriptomics. In addition, the result supports a polyphyletic origin of the genus Physarum and calls for a reevaluation of current taxonomy.

  8. Know Your Chromosomes

    Indian Academy of Sciences (India)

    In each of our cells there is about 6 feet long DNA packed. Into 46 units called chromosomes. Chromosome: is a long thread of DNA wrapped around proteins. ... application of. Mendel's 'gene' concept to a human trait was' by the physician A. Garrod. He described the genetic disease alkaptonuria as an alteration In specific.

  9. Know Your Chromosomes

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 6. Know Your Chromosomes Hybrid Cells and Human Chromosomes. Vani Brahmachari. Series Article Volume 1 Issue 6 June 1996 pp 41-49. Fulltext. Click here to view fulltext PDF. Permanent link:

  10. Know Your Chromosomes

    Indian Academy of Sciences (India)

    These pieces of DNA which are clusters of several genes are called linkages groups or chromosomes. Therefore chromosomes are nothing but long. Cen. DNA. A,denin~ .... and as precursors for other biomolecules like hormones, purines and pyrimidines. ... in the history of science, Garrod's contributions to human genet-.

  11. 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)

  12. Hypoxia attenuates purinergic P2X receptor-induced inflammatory gene expression in brainstem microglia

    Directory of Open Access Journals (Sweden)

    Smith SMC

    2013-08-01

    4 correlated only with iNOS. In addition, correlations between P2X7 and P2X4 were lost following hypoxia, suggesting that P2X4 and P2X7 receptor signaling differs in normoxia and hypoxia. Together, these data suggest that hypoxia suppresses P2X receptor-induced inflammatory gene expression, indicating a potentially immunosuppressive role of extracellular nucleotides in brainstem microglia following exposure to hypoxia.Keywords: P2X4, P2X7, P2X1, BzATP, inflammation, cytokine

  13. Single cell Hi-C reveals cell-to-cell variability in chromosome structure

    Science.gov (United States)

    Schoenfelder, Stefan; Yaffe, Eitan; Dean, Wendy; Laue, Ernest D.; Tanay, Amos; Fraser, Peter

    2013-01-01

    Large-scale chromosome structure and spatial nuclear arrangement have been linked to control of gene expression and DNA replication and repair. Genomic techniques based on chromosome conformation capture assess contacts for millions of loci simultaneously, but do so by averaging chromosome conformations from millions of nuclei. Here we introduce single cell Hi-C, combined with genome-wide statistical analysis and structural modeling of single copy X chromosomes, to show that individual chromosomes maintain domain organisation at the megabase scale, but show variable cell-to-cell chromosome territory structures at larger scales. Despite this structural stochasticity, localisation of active gene domains to boundaries of territories is a hallmark of chromosomal conformation. Single cell Hi-C data bridge current gaps between genomics and microscopy studies of chromosomes, demonstrating how modular organisation underlies dynamic chromosome structure, and how this structure is probabilistically linked with genome activity patterns. PMID:24067610

  14. Combined fluorescent-chromogenic in situ hybridization for identification and laser microdissection of interphase chromosomes.

    Directory of Open Access Journals (Sweden)

    Nerea Paz

    Full Text Available Chromosome territories constitute the most conspicuous feature of nuclear architecture, and they exhibit non-random distribution patterns in the interphase nucleus. We observed that in cell nuclei from humans with Down Syndrome two chromosomes 21 frequently localize proximal to one another and distant from the third chromosome. To systematically investigate whether the proximally positioned chromosomes were always the same in all cells, we developed an approach consisting of sequential FISH and CISH combined with laser-microdissection of chromosomes from the interphase nucleus and followed by subsequent chromosome identification by microsatellite allele genotyping. This approach identified proximally positioned chromosomes from cultured cells, and the analysis showed that the identity of the chromosomes proximally positioned varies. However, the data suggest that there may be a tendency of the same chromosomes to be positioned close to each other in the interphase nucleus of trisomic cells. The protocol described here represents a powerful new method for genome analysis.

  15. The human Y chromosome: a masculine chromosome

    NARCIS (Netherlands)

    Noordam, Michiel J.; Repping, Sjoerd

    2006-01-01

    Once considered to be a genetic wasteland of no scientific interest beyond sex determination, the human Y chromosome has made a significant comeback in the past few decades and is currently implicated in multiple diseases, including spermatogenic failure - absent or very low levels of sperm

  16. Targets for, and consequences of, radiation-induced chromosomal instability

    Science.gov (United States)

    Kaplan, Mark Isaac

    Chromosomal instability has been demonstrated in a human- hamster hybrid cell line, GM10115, after exposure to x- rays. Chromosomal instability in these cells is characterized by the appearance of novel chromosomal rearrangements multiple generations after exposure to ionizing radiation. To identify the cellular target(s) for radiation-induced chromosomal instability, cells were treated with 125I-labeled compounds. Labeling cells with 125I-iododeoxyuridine, which caused radiation damage to the DNA and associated nuclear structures, did induce chromosomal instability. While cell killing and first-division chromosomal rearrangements increased with increasing numbers of 125I decays, the frequency of chromosomal instability was independent of dose. Incorporation of an 125I-labeled protein, 125I-succinyl- concanavalin A, into either the plasma membrane or the cytoplasm, failed to elicit chromosomal instability. These results show that radiation damage to the nucleus, and not to extranuclear regions, contributes to the induction of chromosomal instability. To determine the role of DNA strand breaks as a molecular lesion responsible for initiating chromosomal instability, cells were treated with a variety of DNA strand breaking agents. Agents capable of producing complex DNA double strand breaks, including X-rays, Neocarzinostatin and bleomycin, were able to induce chromosomal instability. In contrast, double strand breaks produced by restriction endonucleases as well as DNA strand breaks produced by hydrogen peroxide failed to induce chromosomal instability. This demonstrates that the type of DNA breakage is important in the eventual manifestation of chromosomal instability. In order to understand the relationship between chromosomal instability and other end points of genomic instability, chromosomally stable and unstable clones were analyzed for sister chromatid exchange, delayed reproductive cell death, delayed mutation, mismatch repair and delayed gene amplification

  17. Chromosome condensation and segmentation

    International Nuclear Information System (INIS)

    Viegas-Pequignot, E.M.

    1981-01-01

    Some aspects of chromosome condensation in mammalians -humans especially- were studied by means of cytogenetic techniques of chromosome banding. Two further approaches were adopted: a study of normal condensation as early as prophase, and an analysis of chromosome segmentation induced by physical (temperature and γ-rays) or chemical agents (base analogues, antibiotics, ...) in order to show out the factors liable to affect condensation. Here 'segmentation' means an abnormal chromosome condensation appearing systematically and being reproducible. The study of normal condensation was made possible by the development of a technique based on cell synchronization by thymidine and giving prophasic and prometaphasic cells. Besides, the possibility of inducing R-banding segmentations on these cells by BrdU (5-bromodeoxyuridine) allowed a much finer analysis of karyotypes. Another technique was developed using 5-ACR (5-azacytidine), it allowed to induce a segmentation similar to the one obtained using BrdU and identify heterochromatic areas rich in G-C bases pairs [fr

  18. Chromosomal abnormalities and autism

    Directory of Open Access Journals (Sweden)

    Farida El-Baz

    2016-01-01

    Conclusion: Chromosomal abnormalities were not detected in the studied autistic children, and so the relation between the genetics and autism still needs further work up with different study methods and techniques.

  19. Chromosomal Abnormalties with Epilepsy

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2005-02-01

    Full Text Available The correlation between specific chromosome abnormalties and various epilepsies was investigated by a study of 76 patients’ records obtained by questionnaires distributed to members of Kyoto Multi-institutional Study Group of Pediatric Neurology.

  20. Fetal chromosome analysis: screening for chromosome disease?

    DEFF Research Database (Denmark)

    Philip, J; Tabor, Ann; Bang, J

    1983-01-01

    with women without elevated risk. Spontaneous abortion rate and prematurity rate did not differ from rates expected without amniocentesis. It is concluded that current indications may be characterized as a mixture of evident high risk factors and factors with only a minor influence on risk. Indications...... who want it, is discussed. Screening for chromosome disease in all pregnancies is not without problems, but may be reasonable in some localities....

  1. Chromosome numbers in Bromeliaceae

    OpenAIRE

    Cotias-de-Oliveira,Ana Lúcia Pires; Assis,José Geraldo Aquino de; Bellintani,Moema Cortizo; Andrade,Jorge Clarêncio Souza; Guedes,Maria Lenise Silva

    2000-01-01

    The present study reports chromosome numbers of 17 species of Bromeliaceae, belonging to the genera Encholirium, Bromelia, Orthophytum, Hohenbergia, Billbergia, Neoglaziovia, Aechmea, Cryptanthus and Ananas. Most species present 2n = 50, however, Bromelia laciniosa, Orthophytum burle-marxii and O. maracasense are polyploids with 2n = 150, 2n = 100 and 2n = 150, respectively, while for Cryptanthus bahianus, 2n = 34 + 1-4B. B chromosomes were observed in Bromelia plumieri and Hohenbergia aff. u...

  2. Chromosomal Evolution in Chiroptera

    OpenAIRE

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

    2017-01-01

    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 d...

  3. Activation of X Chromosome Inactivation

    NARCIS (Netherlands)

    C.M. Maduro (Cheryl)

    2016-01-01

    markdownabstractIn mammals, males are the heterogametic sex having an X chromosome and a Y chromosome whereas females have two X chromosomes. Despite originating from an ancient homologous autosomal pair, the X and Y chromosome now differ greatly in size and gene content after ~180 MY of evolution.

  4. The chromosomal radiosensitivity of lymphocytes from the chimpanzee (Pan troglodytes)

    International Nuclear Information System (INIS)

    Leonard, A.; Decat, G.; Leonard, E.D.; Mortelmans, J.

    1977-01-01

    The yield of chromosomal aberrations induced by exposure to X-irradiation in vitro was studied in the lymphocytes of the chimpanzee (Pan troglodytes), a hominoid ape phylogenically and chromosomally closely related to man. In agreement with the similarity of the chromosome characteristics, no significant difference was observed between man and chimpanzee with respect to the incidence of dicentrics and fragments. It is obvious that the nuclear area, which apparently constitutes the most evident difference between the nuclei of man and chimpanzee lymphocytes, did not play an important role in the yields of aberrations

  5. Matefin/SUN-1 phosphorylation is part of a surveillance mechanism to coordinate chromosome synapsis and recombination with meiotic progression and chromosome movement.

    Directory of Open Access Journals (Sweden)

    Alexander Woglar

    Full Text Available Faithful chromosome segregation during meiosis I depends on the establishment of a crossover between homologous chromosomes. This requires induction of DNA double-strand breaks (DSBs, alignment of homologs, homolog association by synapsis, and repair of DSBs via homologous recombination. The success of these events requires coordination between chromosomal events and meiotic progression. The conserved SUN/KASH nuclear envelope bridge establishes transient linkages between chromosome ends and cytoskeletal forces during meiosis. In Caenorhabditis elegans, this bridge is essential for bringing homologs together and preventing nonhomologous synapsis. Chromosome movement takes place during synapsis and recombination. Concomitant with the onset of chromosome movement, SUN-1 clusters at chromosome ends associated with the nuclear envelope, and it is phosphorylated in a chk-2- and plk-2-dependent manner. Identification of all SUN-1 phosphomodifications at its nuclear N terminus allowed us to address their role in prophase I. Failures in recombination and synapsis led to persistent phosphorylations, which are required to elicit a delay in progression. Unfinished meiotic tasks elicited sustained recruitment of PLK-2 to chromosome ends in a SUN-1 phosphorylation-dependent manner that is required for continued chromosome movement and characteristic of a zygotene arrest. Furthermore, SUN-1 phosphorylation supported efficient synapsis. We propose that signals emanating from a failure to successfully finish meiotic tasks are integrated at the nuclear periphery to regulate chromosome end-led movement and meiotic progression. The single unsynapsed X chromosome in male meiosis is precluded from inducing a progression delay, and we found it was devoid of a population of phosphorylated SUN-1. This suggests that SUN-1 phosphorylation is critical to delaying meiosis in response to perturbed synapsis. SUN-1 may be an integral part of a checkpoint system to monitor

  6. Chromosome numbers in Bromeliaceae

    Directory of Open Access Journals (Sweden)

    Cotias-de-Oliveira Ana Lúcia Pires

    2000-01-01

    Full Text Available The present study reports chromosome numbers of 17 species of Bromeliaceae, belonging to the genera Encholirium, Bromelia, Orthophytum, Hohenbergia, Billbergia, Neoglaziovia, Aechmea, Cryptanthus and Ananas. Most species present 2n = 50, however, Bromelia laciniosa, Orthophytum burle-marxii and O. maracasense are polyploids with 2n = 150, 2n = 100 and 2n = 150, respectively, while for Cryptanthus bahianus, 2n = 34 + 1-4B. B chromosomes were observed in Bromelia plumieri and Hohenbergia aff. utriculosa. The chromosome number of all species was determined for the first time, except for Billbergia chlorosticta and Cryptanthus bahianus. Our data supports the hypothesis of a basic number of x = 25 for the Bromeliaceae family and decreasing aneuploidy in the genus Cryptanthus.

  7. Chromosome-wide mechanisms to decouple gene expression from gene dose during sex-chromosome evolution

    Science.gov (United States)

    Wheeler, Bayly S; Anderson, Erika; Frøkjær-Jensen, Christian; Bian, Qian; Jorgensen, Erik; Meyer, Barbara J

    2016-01-01

    Changes in chromosome number impair fitness by disrupting the balance of gene expression. Here we analyze mechanisms to compensate for changes in gene dose that accompanied the evolution of sex chromosomes from autosomes. Using single-copy transgenes integrated throughout the Caenorhabditis elegans genome, we show that expression of all X-linked transgenes is balanced between XX hermaphrodites and XO males. However, proximity of a dosage compensation complex (DCC) binding site (rex site) is neither necessary to repress X-linked transgenes nor sufficient to repress transgenes on autosomes. Thus, X is broadly permissive for dosage compensation, and the DCC acts via a chromosome-wide mechanism to balance transcription between sexes. In contrast, no analogous X-chromosome-wide mechanism balances transcription between X and autosomes: expression of compensated hermaphrodite X-linked transgenes is half that of autosomal transgenes. Furthermore, our results argue against an X-chromosome dosage compensation model contingent upon rex-directed positioning of X relative to the nuclear periphery. DOI: http://dx.doi.org/10.7554/eLife.17365.001 PMID:27572259

  8. The Y Chromosome

    Science.gov (United States)

    Offner, Susan

    2010-01-01

    The Y chromosome is of great interest to students and can be used to teach about many important biological concepts in addition to sex determination. This paper discusses mutation, recombination, mammalian sex determination, sex determination in general, and the evolution of sex determination in mammals. It includes a student activity that…

  9. Know Your Chromosomes

    Indian Academy of Sciences (India)

    ... of Science Education; Volume 1; Issue 3. Know Your Chromosomes The Strong Holds of Family Trees. Vani Brahmachari. Series Article Volume 1 Issue 3 March 1996 pp 30-38 ... Author Affiliations. Vani Brahmachari1. Developmental Biology and Genetics Laboratory, Indian Institute of Science, Bangalore 560 012, India.

  10. Chromosomes, cancer and radiosensitivity

    International Nuclear Information System (INIS)

    Samouhos, E.

    1983-01-01

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

  11. Chromosomal abnormalities and autism

    African Journals Online (AJOL)

    Farida El-Baz

    2015-06-19

    Jun 19, 2015 ... ORIGINAL ARTICLE. Chromosomal abnormalities and autism. Farida El-Baz a. , Mohamed Saad Zaghloul a. , Ezzat El Sobky a. ,. Reham M Elhossiny a,. *, Heba Salah a. , Neveen Ezy Abdelaziz b a Pediatric Department, Faculty of Medicine, Ain Shams University, Cairo, Egypt b Children with Special ...

  12. Know Your Chromosomes

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 3. Know Your Chromosomes The Strong Holds of Family Trees. Vani Brahmachari. Series Article Volume 1 Issue 3 March 1996 pp 30-38. Fulltext. Click here to view fulltext PDF. Permanent link:

  13. 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

  14. Establishing working standards of chromosome aberrations analysis for biological dosimetry

    International Nuclear Information System (INIS)

    Bui Thi Kim Luyen; Tran Que; Pham Ngoc Duy; Nguyen Thi Kim Anh; Ha Thi Ngoc Lien

    2015-01-01

    Biological dosimetry is an dose assessment method using specify bio markers of radiation. IAEA (International Atomic Energy Agency) and ISO (International Organization for Standardization) defined that dicentric chromosome is specify for radiation, it is a gold standard for biodosimetry. Along with the documents published by IAEA, WHO, ISO and OECD, our results of study on the chromosome aberrations induced by radiation were organized systematically in nine standards that dealing with chromosome aberration test and micronucleus test in human peripheral blood lymphocytes in vitro. This standard addresses: the reference dose-effect for dose estimation, the minimum detection levels, cell culture, slide preparation, scoring procedure for chromosome aberrations use for biodosimetry, the criteria for converting aberration frequency into absorbed dose, reporting of results. Following these standards, the automatic analysis devices were calibrated for improving biological dosimetry method. This standard will be used to acquire and maintain accreditation of the Biological Dosimetry laboratory in Nuclear Research Institute. (author)

  15. Activation of farnesoid X receptor induces RECK expression in mouse liver

    International Nuclear Information System (INIS)

    Peng, Xiaomin; Wu, Weibin; Zhu, Bo; Sun, Zhichao; Ji, Lingling; Ruan, Yuanyuan; Zhou, Meiling; Zhou, Lei; Gu, Jianxin

    2014-01-01

    Highlights: •RECK is a novel transcriptional target gene of FXR in mouse liver. •The FXR response element is located within the intron 1 of RECK gene. •FXR agonist reverses the down-regulation of RECK in the liver in mouse NASH model. -- Abstract: Farnesoid X receptor (FXR) belongs to the ligand-activated nuclear receptor superfamily, and functions as a transcription factor regulating the transcription of numerous genes involved in bile acid homeostasis, lipoprotein and glucose metabolism. In the present study, we identified RECK, a membrane-anchored inhibitor of matrix metalloproteinases, as a novel target gene of FXR in mouse liver. We found that FXR agonist substantially augmented hepatic RECK mRNA and protein expression in vivo and in vitro. FXR regulated the transcription of RECK through directly binding to FXR response element located within intron 1 of the mouse RECK gene. Moreover, FXR agonist reversed the down-regulation of RECK in the livers from mice fed a methionine and choline deficient diet. In summary, our data suggest that RECK is a novel transcriptional target of FXR in mouse liver, and provide clues to better understanding the function of FXR in liver

  16. Activation of farnesoid X receptor induces RECK expression in mouse liver

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Xiaomin [Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai 200032 (China); Wu, Weibin [Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai 200032 (China); Institutes of Biomedical Sciences, Fudan University, Shanghai 200032 (China); Zhu, Bo; Sun, Zhichao; Ji, Lingling; Ruan, Yuanyuan [Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai 200032 (China); Zhou, Meiling, E-mail: meilingzhou2012@gmail.com [Department of Radiology, Zhongshan Hospital of Fudan University and Shanghai Institute of Medical Imaging, Shanghai 200032 (China); Zhou, Lei, E-mail: yhchloech@gmail.com [Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai 200032 (China); Gu, Jianxin [Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai 200032 (China); Institutes of Biomedical Sciences, Fudan University, Shanghai 200032 (China)

    2014-01-03

    Highlights: •RECK is a novel transcriptional target gene of FXR in mouse liver. •The FXR response element is located within the intron 1 of RECK gene. •FXR agonist reverses the down-regulation of RECK in the liver in mouse NASH model. -- Abstract: Farnesoid X receptor (FXR) belongs to the ligand-activated nuclear receptor superfamily, and functions as a transcription factor regulating the transcription of numerous genes involved in bile acid homeostasis, lipoprotein and glucose metabolism. In the present study, we identified RECK, a membrane-anchored inhibitor of matrix metalloproteinases, as a novel target gene of FXR in mouse liver. We found that FXR agonist substantially augmented hepatic RECK mRNA and protein expression in vivo and in vitro. FXR regulated the transcription of RECK through directly binding to FXR response element located within intron 1 of the mouse RECK gene. Moreover, FXR agonist reversed the down-regulation of RECK in the livers from mice fed a methionine and choline deficient diet. In summary, our data suggest that RECK is a novel transcriptional target of FXR in mouse liver, and provide clues to better understanding the function of FXR in liver.

  17. The chromosome cycle of prokaryotes

    Science.gov (United States)

    Kuzminov, Andrei

    2013-01-01

    Summary In both eukaryotes and prokaryotes, chromosomal DNA undergoes replication, condensation-decondensation and segregation, sequentially, in some fixed order. Other conditions, like sister-chromatid cohesion (SCC), may span several chromosomal events. One set of these chromosomal transactions within a single cell cycle constitutes the “chromosome cycle”. For many years it was generally assumed that the prokaryotic chromosome cycle follows major phases of the eukaryotic one: -replication-condensation-segregation-(cell division)-decondensation-, with SCC of unspecified length. Eventually it became evident that, in contrast to the strictly consecutive chromosome cycle of eukaryotes, all stages of the prokaryotic chromosome cycle run concurrently. Thus, prokaryotes practice “progressive” chromosome segregation separated from replication by a brief SCC, and all three transactions move along the chromosome at the same fast rate. In other words, in addition to replication forks, there are “segregation forks” in prokaryotic chromosomes. Moreover, the bulk of prokaryotic DNA outside the replication-segregation transition stays compacted. I consider possible origins of this concurrent replication-segregation and outline the “nucleoid administration” system that organizes the dynamic part of the prokaryotic chromosome cycle. PMID:23962352

  18. Electochemical detection of chromosome translocation

    DEFF Research Database (Denmark)

    Kwasny, Dorota; Dimaki, Maria; Silahtaroglu, Asli

    2014-01-01

    impedance spectroscopy was selected as the sensing method on a microfabricated chip with array of 12 electrode sets. Two independent chips (Chip1 and Chip2) were used for targeting the chromosomal fragments involved in the translocation. Each chip was differentially functionalized with DNA probes matching......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...

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

    Directory of Open Access Journals (Sweden)

    T Cremer

    2009-06-01

    Full Text Available It is now generally accepted that chromosomes in the cell nucleus are organized in distinct domains, first called chromosome territories in 1909 by the great cytologist Theodor Boveri. Yet, even today chromosomes have remained enigmatic individuals, whose structures, arrangements and functions in cycling and post-mitotic cells still need to be explored in full detail. Whereas numerous recent reviews describe present evidence for a dynamic architecture of chromosome territories and discuss the potential significance within the functional compartmentalization of the nucleus, a comprehensive historical account of this important concept of nuclear organization was lacking so far. Here, we describe the early rise of chromosome territories within the context of the discovery of chromosomes and their fundamental role in heredity, covering a period from the 1870th to the early 20th century (part I, this volume. In part II (next volume we review the abandonment of the chromosome territory concept during the 1950th to 1980th and the compelling evidence, which led to its resurrection during the 1970th to 1980th.

  20. Cytological effects of oxytocic agents on mitotic chromosomes of ...

    African Journals Online (AJOL)

    These include disturbed prophase, spindle inhibition, star metaphase, chromatid bridge, precocious chromosome and even nuclear disintegration. The percentage of abnormal cells increased with increase in concentration of treatment drugs and duration of treatment. The possible reasons for the low mitotic index, ...

  1. Unraveling a three-step spatiotemporal mechanism of triggering of receptor-induced Nipah virus fusion and cell entry.

    Directory of Open Access Journals (Sweden)

    Qian Liu

    Full Text Available Membrane fusion is essential for entry of the biomedically-important paramyxoviruses into their host cells (viral-cell fusion, and for syncytia formation (cell-cell fusion, often induced by paramyxoviral infections [e.g. those of the deadly Nipah virus (NiV]. For most paramyxoviruses, membrane fusion requires two viral glycoproteins. Upon receptor binding, the attachment glycoprotein (HN/H/G triggers the fusion glycoprotein (F to undergo conformational changes that merge viral and/or cell membranes. However, a significant knowledge gap remains on how HN/H/G couples cell receptor binding to F-triggering. Via interdisciplinary approaches we report the first comprehensive mechanism of NiV membrane fusion triggering, involving three spatiotemporally sequential cell receptor-induced conformational steps in NiV-G: two in the head and one in the stalk. Interestingly, a headless NiV-G mutant was able to trigger NiV-F, and the two head conformational steps were required for the exposure of the stalk domain. Moreover, the headless NiV-G prematurely triggered NiV-F on virions, indicating that the NiV-G head prevents premature triggering of NiV-F on virions by concealing a F-triggering stalk domain until the correct time and place: receptor-binding. Based on these and recent paramyxovirus findings, we present a comprehensive and fundamentally conserved mechanistic model of paramyxovirus membrane fusion triggering and cell entry.

  2. Intraspecific chromosome variability

    Directory of Open Access Journals (Sweden)

    N Dubinin

    2010-12-01

    Full Text Available (Editorial preface. The publication is presented in order to remind us of one of dramatic pages of the history of genetics. It re-opens for the contemporary reader a comprehensive work marking the priority change from plant cytogenetics to animal cytogenetics led by wide population studies which were conducted on Drosophila polytene chromosomes. The year of the publication (1937 became the point of irretrievable branching between the directions of Old World and New World genetics connected with the problems of chromosome variability and its significance for the evolution of the species. The famous book of T. Dobzhansky (1937 was published by Columbia University in the US under the title “Genetics and the origin of species”, and in the shadow of this American ‘skybuilding’ all other works grew dim. It is remarkable that both Dobzhansky and Dubinin come to similar conclusions about the role of chromosomes in speciation. This is not surprising given that they both might be considered as representatives of the Russian genetic school, by their birth and education. Interestingly, Dobzhansky had never referred to the full paper of Dubinin et al. (1937, though a previous short communication in Nature (1936 was included together with all former papers on the related subject. In full, the volume of the original publication printed in the Biological Journal in Moscow comprised 47 pages, in that number 41 pages of the Russian text accompanied by 16 Figs, a table and reference list, and, above all, 6 pages of the English summary. This final part in English is now reproduced in the authors’ version with the only addition being the reference list in the originally printed form.

  3. X Chromosome Evolution in Cetartiodactyla.

    Science.gov (United States)

    Proskuryakova, Anastasia A; Kulemzina, Anastasia I; Perelman, Polina L; Makunin, Alexey I; Larkin, Denis M; Farré, Marta; Kukekova, Anna V; Lynn Johnson, Jennifer; Lemskaya, Natalya A; Beklemisheva, Violetta R; Roelke-Parker, Melody E; Bellizzi, June; Ryder, Oliver A; O'Brien, Stephen J; Graphodatsky, Alexander S

    2017-08-31

    The phenomenon of a remarkable conservation of the X chromosome in eutherian mammals has been first described by Susumu Ohno in 1964. A notable exception is the cetartiodactyl X chromosome, which varies widely in morphology and G-banding pattern between species. It is hypothesized that this sex chromosome has undergone multiple rearrangements that changed the centromere position and the order of syntenic segments over the last 80 million years of Cetartiodactyla speciation. To investigate its evolution we have selected 26 evolutionarily conserved bacterial artificial chromosome (BAC) clones from the cattle CHORI-240 library evenly distributed along the cattle X chromosome. High-resolution BAC maps of the X chromosome on a representative range of cetartiodactyl species from different branches: pig (Suidae), alpaca (Camelidae), gray whale (Cetacea), hippopotamus (Hippopotamidae), Java mouse-deer (Tragulidae), pronghorn (Antilocapridae), Siberian musk deer (Moschidae), and giraffe (Giraffidae) were obtained by fluorescent in situ hybridization. To trace the X chromosome evolution during fast radiation in specious families, we performed mapping in several cervids (moose, Siberian roe deer, fallow deer, and Pere David's deer) and bovid (muskox, goat, sheep, sable antelope, and cattle) species. We have identified three major conserved synteny blocks and rearrangements in different cetartiodactyl lineages and found that the recently described phenomenon of the evolutionary new centromere emergence has taken place in the X chromosome evolution of Cetartiodactyla at least five times. We propose the structure of the putative ancestral cetartiodactyl X chromosome by reconstructing the order of syntenic segments and centromere position for key groups.

  4. Micromechanical study of protein-DNA interactions and chromosomes

    Science.gov (United States)

    Marko, John

    I will discuss micromechanics experiments that our group has used to analyze protein-DNA interactions and chromosome organization. In single-DNA experiments we have found that a feature of protein-DNA complexes is that their dissociation rates can depend strikingly on bulk solution concentrations of other proteins and DNA segments; I will describe experiments which demonstrate this effect, which can involve tens-fold changes in off-rates with submicromolar changes in solution concentrations. Second, I will discuss experiments aimed at analyzing large-scale human chromosome structure; we isolate metaphase chromosomes, which in their native form behave as remarkably elastic networks of chromatin. Exposure to DNA-cutting restriction enzymes completely eliminates this elasticity, indicating that there is not a mechanically contiguous protein ''scaffold'' from which the chromosome gains its stability. I will show results of siRNA experiments indicating that depletion of condensin proteins leads to destabilization of chromosome mechanics, indicating condensin's role as the major chromatin ''cross-linker'' in metaphase chromosomes. Finally I will discuss similar experiments on human G1 nuclei, where we use genetic and chemical modifications to separate the contributions of the nuclear lamina and chromatin to the mechanical stiffness of the nucleus as a whole. Supported by the NSF (DMR-1206868, MCB-1022117) and the NIH (GM105847, CA193419).

  5. X chromosome and suicide.

    Science.gov (United States)

    Fiori, L M; Zouk, H; Himmelman, C; Turecki, G

    2011-02-01

    Suicide completion rates are significantly higher in males than females in most societies. Although gender differences in suicide rates have been partially explained by environmental and behavioral factors, it is possible that genetic factors, through differential expression between genders, may also help explain gender moderation of suicide risk. This study investigated X-linked genes in suicide completers using a two-step strategy. We first took advantage of the genetic structure of the French-Canadian population and genotyped 722 unrelated French-Canadian male subjects, of whom 333 were suicide completers and 389 were non-suicide controls, using a panel of 37 microsatellite markers spanning the entire X chromosome. Nine haplotype windows and several individual markers were associated with suicide. Significant results aggregated primarily in two regions, one in the long arm and another in the short arm of chromosome X, limited by markers DXS8051 and DXS8102, and DXS1001 and DXS8106, respectively. The second stage of the study investigated differential brain expression of genes mapping to associated regions in Brodmann areas 8/9, 11, 44 and 46, in an independent sample of suicide completers and controls. Six genes within these regions, Rho GTPase-activating protein 6, adaptor-related protein complex 1 sigma 2 subunit, glycoprotein M6B, ribosomal protein S6 kinase 90  kDa polypeptide 3, spermidine/spermine N(1)-acetyltransferase 1 and THO complex 2, were found to be differentially expressed in suicide completers.

  6. Chromosome number distribution and cellular DNA content in colorectal adenomas from polyposis and nonpolyposis patients

    DEFF Research Database (Denmark)

    Petersen, S E; Madsen, A L; Bak, Martin

    1991-01-01

    and a correspondingly increased nuclear DNA content. In another two adenomas, the DNA analyses showed small hyperploid populations constituting 6% and 2% of the cells. The most striking difference between the DNA analyses and chromosome number distributions was that 13% of all metaphases were hyperploid with chromosome......Ploidy analyses of colorectal adenomas were performed by combined flow cytometric DNA analysis of unfixed isolated nuclei and direct chromosome preparation after Colcemid incubation for 9-20 hours. Ten of 18 adenomas from nonpolyposis patients and 4 of 13 adenomas from patients with familial...... adenomatous polyposis yielded a mean of 25 countable metaphases (range 7-44) per tumor. Of 343 metaphases, only 38% had 46 chromosomes, and 62% were nondiploid. All but one adenoma had diploid or peridiploid modes in the range of 46-50 chromosomes. One adenoma was hyperploid, with a mode of 74 chromosomes...

  7. A strategy for constructing aneuploid yeast strains by transient nondisjunction of a target chromosome

    Directory of Open Access Journals (Sweden)

    Peck Anders T

    2009-07-01

    Full Text Available Abstract Background Most methods for constructing aneuploid yeast strains that have gained a specific chromosome rely on spontaneous failures of cell division fidelity. In Saccharomyces cerevisiae, extra chromosomes can be obtained when errors in meiosis or mitosis lead to nondisjunction, or when nuclear breakdown occurs in heterokaryons. We describe a strategy for constructing N+1 disomes that does not require such spontaneous failures. The method combines two well-characterized genetic tools: a conditional centromere that transiently blocks disjunction of one specific chromosome, and a duplication marker assay that identifies disomes among daughter cells. To test the strategy, we targeted chromosomes III, IV, and VI for duplication. Results The centromere of each chromosome was replaced by a centromere that can be blocked by growth in galactose, and ura3::HIS3, a duplication marker. Transient exposure to galactose induced the appearance of colonies carrying duplicated markers for chromosomes III or IV, but not VI. Microarray-based comparative genomic hybridization (CGH confirmed that disomic strains carrying extra chromosome III or IV were generated. Chromosome VI contains several genes that are known to be deleterious when overexpressed, including the beta-tubulin gene TUB2. To test whether a tubulin stoichiometry imbalance is necessary for the apparent lethality caused by an extra chromosome VI, we supplied the parent strain with extra copies of the alpha-tubulin gene TUB1, then induced nondisjunction. Galactose-dependent chromosome VI disomes were produced, as revealed by CGH. Some chromosome VI disomes also carried extra, unselected copies of additional chromosomes. Conclusion This method causes efficient nondisjunction of a targeted chromosome and allows resulting disomic cells to be identified and maintained. We used the method to test the role of tubulin imbalance in the apparent lethality of disomic chromosome VI. Our results indicate

  8. 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…

  9. Description of a ZZ/ZW sex chromosome system in Thoracocharax cf. stellatus (Teleostei, Characiformes, Gasteropelecidae

    Directory of Open Access Journals (Sweden)

    Carvalho Margarida Lima

    2002-01-01

    Full Text Available The family Gasteropelecidae is composed of three genera and eight species. This study shows that Thoracocharax cf. stellatus has 2n = 52 chromosomes for both sexes. The five males studied showed 8 metacentric, 16 submetacentric, 4 subtelocentric, and 24 acrocentric chromosomes; the seven females showed only one submetacentric chromosome, belonging to pair 11, and one extra acrocentric chromosome, smaller than all the other chromosomes, characterizing the presence of a ZZ/ZW sex chromosome system in this species. Nucleolus organizing regions (NORs were detected on the short arms of the subtelocentric chromosome pair 13. Constitutive heterochromatin was identified at pericentromeric and terminal positions in almost all chromosomes. The W chromosome was almost entirely heterochromatic, except for a small terminal euchromatic segment. The analyses of the amount of nuclear DNA found 2.18 ± 0.09 pg of DNA per diploid nucleus, without significant differences between sexes. A discussion about the evolution of the sex chromosomes in this group is presented.

  10. Ki-67 acts as a biological surfactant to disperse mitotic chromosomes

    Science.gov (United States)

    Cuylen, Sara; Blaukopf, Claudia; Politi, Antonio Z.; Müller-Reichert, Thomas; Neumann, Beate; Poser, Ina; Ellenberg, Jan; Hyman, Anthony A.; Gerlich, Daniel W.

    2016-01-01

    Summary Eukaryotic genomes are partitioned into chromosomes, which during mitosis form compact and spatially well-separated mechanical bodies1–3.This enables chromosomes to move independently of each other for segregation of precisely one copy of the genome to each of the nascent daughter cells. Despite insights into the spatial organization of mitotic chromosomes4 and the discovery of proteins at the chromosome surface3,5,6, the molecular and biophysical basis of mitotic chromosome individuality have remained unclear. We report that Ki-67, a component of the mitotic chromosome periphery, prevents chromosomes from collapsing into a single chromatin mass after nuclear envelope disassembly, thus enabling independent chromosome motility and efficient interactions with the mitotic spindle. The chromosome separation function of Ki-67 is not confined within a specific protein domain but correlates with size and net charge of truncation mutants that apparently lack secondary structure. This suggests that Ki-67 forms a steric and electrical barrier, similar to surface-active agents (surfactants) that disperse particles or phase-separated liquid droplets in solvents. Fluorescence correlation spectroscopy showed a high surface density of Ki-67 and dual-color labeling of both protein termini revealed an extended molecular conformation, indicating brush-like arrangements that are characteristic for polymeric surfactants. Our study thus elucidates a biomechanical role of the mitotic chromosome periphery and suggests that natural proteins can function as surfactants in intracellular compartmentalization. PMID:27362226

  11. Chromosomal rearrangements occurred repeatedly and ...

    African Journals Online (AJOL)

    Furthermore, molecular and/or chromosomal data indicate that Paroedura is a monophyletic genus, in which chromosome rearrangements occurred repeatedly and independently during the specific diversification. Moreover both P. bastardi and P. gracilis in current definitions are paraphyletic assemblages of several ...

  12. Sex chromosomes in Ephestia kuehniella

    Czech Academy of Sciences Publication Activity Database

    Marec, František; Sahara, K.; Traut, W.

    2001-01-01

    Roč. 44, č. 1 (2001), s. 131 ISSN 0003-3995. [European Cytogenetics Conference /3./. 07.07.2001-10.07.2001, Paris] Institutional research plan: CEZ:AV0Z5007907 Keywords : Telomere * sex chromosomes * chromosome fragments Subject RIV: EB - Genetics ; Molecular Biology

  13. 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

  14. Schizophrenia and chromosomal deletions

    Energy Technology Data Exchange (ETDEWEB)

    Lindsay, E.A.; Baldini, A. [Baylor College of Medicine, Houston, TX (United States); Morris, M. A. [Univ. of Geneva School of Medicine, NY (United States)] [and others

    1995-06-01

    Recent genetic linkage analysis studies have suggested the presence of a schizophrenia locus on the chromosomal region 22q11-q13. Schizophrenia has also been frequently observed in patients affected with velo-cardio-facial syndrome (VCFS), a disorder frequently associated with deletions within 22q11.1. It has been hypothesized that psychosis in VCFS may be due to deletion of the catechol-o-methyl transferase gene. Prompted by these observations, we screened for 22q11 deletions in a population of 100 schizophrenics selected from the Maryland Epidemiological Sample. Our results show that there are schizophrenic patients carrying a deletion of 22q11.1 and a mild VCFS phenotype that might remain unrecognized. These findings should encourage a search for a schizophrenia-susceptibility gene within the deleted region and alert those in clinical practice to the possible presence of a mild VCFS phenotype associated with schizophrenia. 9 refs.

  15. Field-flow fractionation of chromosomes

    Energy Technology Data Exchange (ETDEWEB)

    Giddings, J.C.

    1990-09-01

    Research continued on field flow fractionation of chromosomes. Progress in the past year can be organized into three main categories: (1) chromosome sample preparation; (2) preliminary chromosome fractionation; (3) fractionation of a polystyrene aggregate model which approximates the chromosome shape. We have been successful in isolating metaphase chromosomes from the Chinese hamster. We also received a human chromosome sample from Dr. Carolyn Bell-Prince of Los Alamos National Laboratory. Results are discussed. 2 figs.

  16. Comparative chromosome mapping of U2 snRNA and 5S rRNA genes in Gymnotus species (Gymnotiformes, Gymnotidae): evolutionary dynamics and sex chromosome linkage in G . pantanal.

    Science.gov (United States)

    Utsunomia, Ricardo; Scacchetti, Priscilla C; Pansonato-Alves, José C; Oliveira, Claudio; Foresti, Fausto

    2014-01-01

    A comparative mapping of U2 small nuclear RNA (snRNA) and 5S ribosomal RNA (rRNA) genes was performed in 6 Gymnotus species. All species analyzed presented the U2 snDNA organized in conspicuous blocks and not co-located with rRNA genes. In addition, 5 species showed the U2 snDNA located in a single pair of chromosomes, which seems to be a conserved trait in this genus. Conversely, G. pantanal was the only species displaying several terminal signals in different chromosome pairs, including the X1 sex chromosome but not the Y chromosome. This is the first report of U2 snRNA genes in sex chromosomes of fishes. The absence of sites in the Y chromosome of G. pantanal indicates a possible loss of terminal segments of the chromosomes involved in the Y formation. © 2014 S. Karger AG, Basel.

  17. Chromatid Painting for Chromosomal Inversion Detection Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose the continued development of a novel approach to the detection of chromosomal inversions. Transmissible chromosome aberrations (translocations and...

  18. Chromatid Painting for Chromosomal Inversion Detection Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose a novel approach to the detection of chromosomal inversions. Transmissible chromosome aberrations (translocations and inversions) have profound genetic...

  19. Procedure Improvement in Blood Processing for Chromosome Aberration Analyst

    International Nuclear Information System (INIS)

    Noraisyah Mohd Yusof; Juliana Mahamad; Rahimah Abd Rahim; Yahaya Talib; Mohd Rodzi Ali

    2015-01-01

    Detection of chromosome at metaphase of the cell cycle is performed either manually or automatically. Procedure for slide preparation published by the IAEA does not guarantee that the quality of slide is suitable for automatic detection. The detection efficiency reduces if there is cells debris on slides. This paper describes the modifications made to the standard procedure. The period of hypotonic treatment to the cell was lengthened; the slides were pre-treated with RNase and the frequency of rinsing during the chromosomal coloring process was increased. Results show the metaphase images were better and clearer, and numbers of metaphase that can be detected automatically were also increased. In conclusion, modification to the current standard protocol helps to easy the process of chromosome aberration analysis at Nuclear Malaysia. (author)

  20. Function of Junk: Pericentromeric Satellite DNA in Chromosome Maintenance.

    Science.gov (United States)

    Jagannathan, Madhav; Yamashita, Yukiko M

    2018-04-02

    Satellite DNAs are simple tandem repeats that exist at centromeric and pericentromeric regions on eukaryotic chromosomes. Unlike the centromeric satellite DNA that comprises the vast majority of natural centromeres, function(s) for the much more abundant pericentromeric satellite repeats are poorly understood. In fact, the lack of coding potential allied with rapid divergence of repeat sequences across eukaryotes has led to their dismissal as "junk DNA" or "selfish parasites." Although implicated in various biological processes, a conserved function for pericentromeric satellite DNA remains unidentified. We have addressed the role of satellite DNA through studying chromocenters, a cytological aggregation of pericentromeric satellite DNA from multiple chromosomes into DNA-dense nuclear foci. We have shown that multivalent satellite DNA-binding proteins cross-link pericentromeric satellite DNA on chromosomes into chromocenters. Disruption of chromocenters results in the formation of micronuclei, which arise by budding off the nucleus during interphase. We propose a model that satellite DNAs are critical chromosome elements that are recognized by satellite DNA-binding proteins and incorporated into chromocenters. We suggest that chromocenters function to preserve the entire chromosomal complement in a single nucleus, a fundamental and unquestioned feature of eukaryotic genomes. We speculate that the rapid divergence of satellite DNA sequences between closely related species results in discordant chromocenter function and may underlie speciation and hybrid incompatibility. © 2017 Jagannathan and Yamashita; Published by Cold Spring Harbor Laboratory Press.

  1. Moving toward a higher efficiency of microcell-mediated chromosome transfer

    Directory of Open Access Journals (Sweden)

    Mikhail Liskovykh

    2016-01-01

    Full Text Available Microcell-mediated chromosome transfer (MMCT technology enables individual mammalian chromosomes, megabase-sized chromosome fragments, or mammalian artificial chromosomes that include human artificial chromosomes (HACs and mouse artificial chromosomes (MACs to be transferred from donor to recipient cells. In the past few decades, MMCT has been applied to various studies, including mapping the genes, analysis of chromosome status such as aneuploidy and epigenetics. Recently, MMCT was applied to transfer MACs/HACs carrying entire chromosomal copies of genes for genes function studies and has potential for regenerative medicine. However, a safe and efficient MMCT technique remains an important challenge. The original MMCT protocol includes treatment of donor cells by Colcemid to induce micronucleation, where each chromosome becomes surrounded with a nuclear membrane, followed by disarrangement of the actin cytoskeleton using Cytochalasin B to help induce microcells formation. In this study, we modified the protocol and demonstrated that replacing Colcemid and Cytochalasin B with TN-16 + Griseofulvin and Latrunculin B in combination with a Collage/Laminin surface coating increases the efficiency of HAC transfer to recipient cells by almost sixfold and is possibly less damaging to HAC than the standard MMCT method. We tested the improved MMCT protocol on four recipient cell lines, including human mesenchymal stem cells and mouse embryonic stem cells that could facilitate the cell engineering by HACs.

  2. Are There Knots in Chromosomes?

    Directory of Open Access Journals (Sweden)

    Jonathan T. Siebert

    2017-08-01

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

  3. Chromosome painting for plant biotechnology.

    Science.gov (United States)

    Kato, Akio; Lamb, Jonathan C; Albert, Patrice S; Danilova, Tatiana; Han, Fangpu; Gao, Zhi; Findley, Seth; Birchler, James A

    2011-01-01

    Fluorescence in situ hybridization (FISH) is an invaluable tool for chromosome analysis and engineering. The ability to visually localize endogenous genes, transposable elements, transgenes, naturally occurring organellar DNA insertions - essentially any unique sequence larger than 2 kb - greatly facilitates progress. This chapter details the labeling procedures and chromosome preparation techniques used to produce high-quality FISH signals on somatic metaphase and meiotic pachytene spreads.

  4. Origin and domestication of papaya Yh chromosome

    Science.gov (United States)

    Sex in papaya is controlled by a pair of nascent sex chromosomes. Females are XX, and two slightly different Y chromosomes distinguish males (XY) and hermaphrodites (XYh). The hermaphrodite-specific region of the Yh chromosome (HSY) and its X chromosome counterpart were sequenced and analyzed previo...

  5. Monosomic analysis reveals duplicated chromosomal segments in ...

    Indian Academy of Sciences (India)

    Monosomic analysis reveals duplicated chromosomal segments in maize genome. MAHESH C. YADAV1,2∗, J. K. S. ... cated chromosomal segments in maize genome. Materials and methods. Development and .... each in chromosomes 2 and 7, while 10 other pairs of du- plicate loci had one copy in chromosome 3 and the ...

  6. Ring chromosome 13 and ambiguous genitalia.

    Science.gov (United States)

    Ozsu, Elif; Yeşiltepe Mutlu, Gül; Ipekçi, Belkıs

    2014-01-01

    Ambiguous genitalia, known to be associated with sex chromosome disorders, may also be seen with autosomal chromosome anomalies. Herein, we report a case with ambiguous genitalia and ring chromosome 13. Ring chromosome 13 is a rare genetic anomaly in which the loss of genetic material determines the clinical spectrum.

  7. Ring Chromosome 13 and Ambiguous Genitalia

    OpenAIRE

    Özsu, Elif; Yeşiltepe Mutlu, Gül; İpekçi, Belkıs

    2014-01-01

    Ambiguous genitalia, known to be associated with sex chromosome disorders, may also be seen with autosomal chromosome anomalies. Herein, we report a case with ambiguous genitalia and ring chromosome 13. Ring chromosome 13 is a rare genetic anomaly in which the loss of genetic material determines the clinical spectrum.

  8. Diagnostic radiation and chromosome aberrations

    International Nuclear Information System (INIS)

    Patil, S.R.; Hecht, F.; Lubs, H.A.; Kimberling, W.; Brown, J.; Gerald, P.S.; Summitt, R.L.

    1977-01-01

    Some evidence is presented suggesting that diagnostic X-rays may be important in the origin of a new chromosomal abnormality other than Down syndrome. Chromosome analyses have been carried out on 4342 children, seven or eight years old. Maternal diagnostic irradiation in the year before conception and up to third lunar month of the index pregnancy was recorded, before the chromosome study began, together with a large amount of family and clinical data. Information on X-ray exposure was supplied by the mothers, s o radiation dosage could not be estimated. 21 children (including a pair of twins and a pair of siblings) born to 19 mothers had chromosomal aberrations. The mothers of six children with inherited translocations, rearrangements and XYY karyotypes were excluded, and 3 (23%) of the remaining 13 mothers had received abdominal and pelvic X-ray exposures. In the whole sample, however, only 6% of the mothers had diagnostic irradiation. Two of these mothers, aged sixteen and twenty, gave birth to a child each with de-novo autosomal translocations, and the third mother, aged thirty-two, had a child with a complex mosaicism involving one X chromosome. Although the sample size of the mothers with chromosomally abnormal children is small, the results are significant. (U.K.)

  9. 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.

  10. Condensins promote chromosome individualization and segregation during mitosis, meiosis, and amitosis inTetrahymena thermophila.

    Science.gov (United States)

    Howard-Till, Rachel; Loidl, Josef

    2018-02-15

    Condensin is a protein complex with diverse functions in chromatin packaging and chromosome condensation and segregation. We studied condensin in the evolutionarily distant protist model Tetrahymena , which features noncanonical nuclear organization and divisions. In Tetrahymena , the germline and soma are partitioned into two different nuclei within a single cell. Consistent with their functional specializations in sexual reproduction and gene expression, condensins of the germline nucleus and the polyploid somatic nucleus are composed of different subunits. Mitosis and meiosis of the germline nucleus and amitotic division of the somatic nucleus are all dependent on condensins. In condensin-depleted cells, a chromosome condensation defect was most striking at meiotic metaphase, when Tetrahymena chromosomes are normally most densely packaged. Live imaging of meiotic divisions in condensin-depleted cells showed repeated nuclear stretching and contraction as the chromosomes failed to separate. Condensin depletion also fundamentally altered chromosome arrangement in the polyploid somatic nucleus: multiple copies of homologous chromosomes tended to cluster, consistent with a previous model of condensin suppressing default somatic pairing. We propose that failure to form discrete chromosome territories is the common cause of the defects observed in the absence of condensins. © 2018 Howard-Till and Loidl. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

  11. Inherited unbalanced structural chromosome abnormalities at prenatal chromosome analysis are rarely ascertained through recurrent miscarriage

    NARCIS (Netherlands)

    Franssen, M. T. M.; Korevaar, J. C.; Tjoa, W. M.; Leschot, N. J.; Bossuyt, P. M. M.; Knegt, A. C.; Suykerbuyk, R. F.; Hochstenbach, R.; van der Veen, F.; Goddijn, M.

    2008-01-01

    OBJECTIVE: To determine the mode of ascertainment of inherited unbalanced structural chromosome abnormalities detected at prenatal chromosome analysis. METHODS: From the databases of three centres for clinical genetics in the Netherlands, all cases of inherited unbalanced structural chromosome

  12. Inherited unbalanced structural chromosome abnormalities at prenatal chromosome analysis are rarely ascertained through recurrent miscarriage

    NARCIS (Netherlands)

    Franssen, M. T. M.; Korevaar, J. C.; Tjoa, W. M.; Leschot, N. J.; Bossuyt, P. M. M.; Knegt, A. C.; Suykerbuyk, R. F.; Hochstenbach, R.; van der Veen, F.; Goddijn, M.

    Objective To determine the mode of ascertainment of inherited unbalanced structural chromosome abnormalities detected at prenatal chromosome analysis. Methods From the databases of three centres for clinical genetics in the Netherlands, all cases of inherited unbalanced structural chromosome

  13. 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

  14. DNA Cross-Bridging Shapes a Single Nucleus from a Set of Mitotic Chromosomes.

    Science.gov (United States)

    Samwer, Matthias; Schneider, Maximilian W G; Hoefler, Rudolf; Schmalhorst, Philipp S; Jude, Julian G; Zuber, Johannes; Gerlich, Daniel W

    2017-08-24

    Eukaryotic cells store their chromosomes in a single nucleus. This is important to maintain genomic integrity, as chromosomes packaged into separate nuclei (micronuclei) are prone to massive DNA damage. During mitosis, higher eukaryotes disassemble their nucleus and release individualized chromosomes for segregation. How numerous chromosomes subsequently reform a single nucleus has remained unclear. Using image-based screening of human cells, we identified barrier-to-autointegration factor (BAF) as a key factor guiding membranes to form a single nucleus. Unexpectedly, nuclear assembly does not require BAF's association with inner nuclear membrane proteins but instead relies on BAF's ability to bridge distant DNA sites. Live-cell imaging and in vitro reconstitution showed that BAF enriches around the mitotic chromosome ensemble to induce a densely cross-bridged chromatin layer that is mechanically stiff and limits membranes to the surface. Our study reveals that BAF-mediated changes in chromosome mechanics underlie nuclear assembly with broad implications for proper genome function. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  15. Radiation-induced chromosomal instability

    Energy Technology Data Exchange (ETDEWEB)

    Ritter, S. [GSI, Biophysics, Darmstadt (Germany)

    1999-03-01

    Recent studies on radiation-induced chromosomal instability in the progeny of exposed mammalian cells were briefly described as well as other related studies. For the analysis of chromosomal damage in clones, cells were seeded directly after exposure in cell well-dish to form single cell clones and post-irradiation chromosome aberrations were scored. Both exposure to isoeffective doses of X-ray or 270 MeV/u C-ions (13 keV/{mu}m) increased the number of clones with abnormal karyotype and the increase was similar for X-ray and for C-ions. Meanwhile, in the progeny of cells for mass cultures, there was no indication of a delayed expression of chromosomal damage up to 40 population doublings after the exposure. A high number of aberrant cells were only observed directly after exposure to 10.7 MeV/u O-ions, i.e. in the first cycle cells and decreased with subsequent cell divisions. The reason for these differences in the radiation-induced chromosomal instability between clonal isolates and mass culture has not been clarified. Recent studies indicated that genomic instability occurs at a high frequency in the progeny of cells irradiated with both sparsely and densely ionizing radiation. Such genomic instability is thought likely to increase the risk of carcinogenesis, but more data are required for a well understanding of the health risks resulting from radiation-induced delayed instability. (M.N.)

  16. Chromosome segregation in plant meiosis

    Directory of Open Access Journals (Sweden)

    Linda eZamariola

    2014-06-01

    Full Text Available Faithful chromosome segregation in meiosis is essential for ploidy stability over sexual life cycles. In plants, defective chromosome segregation caused by gene mutations or other factors leads to the formation of unbalanced or unreduced gametes creating aneuploid or polyploid progeny, respectively. Accurate segregation requires the coordinated execution of conserved processes occurring throughout the two meiotic cell divisions. Synapsis and recombination ensure the establishment of chiasmata that hold homologous chromosomes together allowing their correct segregation in the first meiotic division, which is also tightly regulated by cell-cycle dependent release of cohesin and monopolar attachment of sister kinetochores to microtubules. In meiosis II, bi-orientation of sister kinetochores and proper spindle orientation correctly segregate chromosomes in four haploid cells. Checkpoint mechanisms acting at kinetochores control the accuracy of kinetochore-microtubule attachment, thus ensuring the completion of segregation. Here we review the current knowledge on the processes taking place during chromosome segregation in plant meiosis, focusing on the characterization of the molecular factors involved.

  17. 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

  18. The Smc5-Smc6 complex is required to remove chromosome junctions in meiosis.

    Directory of Open Access Journals (Sweden)

    Sarah Farmer

    Full Text Available Meiosis, a specialized cell division with a single cycle of DNA replication round and two consecutive rounds of nuclear segregation, allows for the exchange of genetic material between parental chromosomes and the formation of haploid gametes. The structural maintenance of chromosome (SMC proteins aid manipulation of chromosome structures inside cells. Eukaryotic SMC complexes include cohesin, condensin and the Smc5-Smc6 complex. Meiotic roles have been discovered for cohesin and condensin. However, although Smc5-Smc6 is known to be required for successful meiotic divisions, the meiotic functions of the complex are not well understood. Here we show that the Smc5-Smc6 complex localizes to specific chromosome regions during meiotic prophase I. We report that meiotic cells lacking Smc5-Smc6 undergo catastrophic meiotic divisions as a consequence of unresolved linkages between chromosomes. Surprisingly, meiotic segregation defects are not rescued by abrogation of Spo11-induced meiotic recombination, indicating that at least some chromosome linkages in smc5-smc6 mutants originate from other cellular processes. These results demonstrate that, as in mitosis, Smc5-Smc6 is required to ensure proper chromosome segregation during meiosis by preventing aberrant recombination intermediates between homologous chromosomes.

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

    Indian Academy of Sciences (India)

    2010-09-06

    Sep 6, 2010 ... Institut für Biologie, Zentrum für medizinische Struktur- und Zellbiologie, Universität Lübeck,. Ratzeburger Allee 160, D-23538 Lübeck, Germany. Abstract. The phorid fly Megaselia scalaris is a laboratory model for the turnover and early differentiation of sex chromosomes. Isolates from the field have an XY ...

  20. Clipboard Human Y-chromosome

    Indian Academy of Sciences (India)

    Unknown

    Their findings, as described below, are revealing. They sequenced the euchromatic part of the Y-chromosome (23 Mb) (obtained from a single anony- mous human male), comprising 8 Mb of the short arm (Yp) and 14⋅5 Mb of the long arm (Yq), at an accuracy of 99⋅999% and classified these regions into three sequence ...

  1. Chromosomes go with the flow

    Czech Academy of Sciences Publication Activity Database

    Doležel, Jaroslav; Carter, N.; Ferguson-Smith, M. A.

    2004-01-01

    Roč. 12, č. 1 (2004), s. 1-4 ISSN 0967-3849 R&D Projects: GA ČR GA521/04/0607; GA ČR GA521/03/0595 Institutional research plan: CEZ:AV0Z5038910 Keywords : flow cytometry * chromosomes Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.346, year: 2004

  2. Algorithm for sorting chromosomal aberrations

    DEFF Research Database (Denmark)

    Vogel, Ida; Lund, Najaaraq; Rasmussen, Steen

    2017-01-01

    Prenatal diagnostic methods and screening procedures change rapidly in these years. Years ago only karyotyping was performed prenatally, and we monitored only Down syndrome(1) . Since then the diagnostic possibilities have increased to QF-PCR, FISH, MLPA and chromosomal microarray....

  3. Vibrio chromosome-specific families

    DEFF Research Database (Denmark)

    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...

  4. Genomic disorders on chromosome 22.

    Science.gov (United States)

    Yu, Shihui; Graf, William D; Shprintzen, Robert J

    2012-12-01

    Chromosome 22, the first human chromosome to be completely sequenced, is prone to genomic alterations. Copy-number variants (CNVs) are common because of an enrichment of low-copy repeat sequences that precipitate a high frequency of nonallelic homologous misalignments and unequal recombination during meiosis. Among these is one of the most common multiple anomaly syndromes in humans and the most common microdeletion syndrome, velocardiofacial syndrome (VCFS), also known as 22q11.2 deletion syndrome and DiGeorge syndrome. This review will focus on the recent literature dealing with both the molecular and clinical aspects of chromosome 22 genomic variations. Although the literature covering this area is expansive, the majority is descriptive or analytical of the problems presented by these genomic disorders, and there is little evidence of translational research including treatment outcomes. With the increased use of microarray analysis in both research and clinical practice, variations in CNVs are becoming elucidated. Genomic analysis continues to characterize genes and gene effect. Research on the COMT gene continues to yield interesting findings, including a possible sex-mediated effect because of its regulatory role with estrogen. There is a small amount of treatment outcome data relevant to neuropsychiatric disorders in VCFS, but based on small samples and short-term follow-up. Although hundreds of studies in the past year have focused on genomic disorders of chromosome 22, little progress has been made in the implementation of translational research, even for more common disorders including VCFS.

  5. Chromosomal abnormalities associated with omphalocele.

    Science.gov (United States)

    Chen, Chih-Ping

    2007-03-01

    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.

  6. 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.

  7. Chromosome Aberrations by Heavy Ions

    Science.gov (United States)

    Ballarini, Francesca; Ottolenghi, Andrea

    It is well known that mammalian cells exposed to ionizing radiation can show different types of chromosome aberrations (CAs) including dicentrics, translocations, rings, deletions and complex exchanges. Chromosome aberrations are a particularly relevant endpoint in radiobiology, because they play a fundamental role in the pathways leading either to cell death, or to cell conversion to malignancy. In particular, reciprocal translocations involving pairs of specific genes are strongly correlated (and probably also causally-related) with specific tumour types; a typical example is the BCR-ABL translocation for Chronic Myeloid Leukaemia. Furthermore, aberrations can be used for applications in biodosimetry and more generally as biomarkers of exposure and risk, that is the case for cancer patients monitored during Carbon-ion therapy and astronauts exposed to space radiation. Indeed hadron therapy and astronauts' exposure to space radiation represent two of the few scenarios where human beings can be exposed to heavy ions. After a brief introduction on the main general features of chromosome aberrations, in this work we will address key aspects of the current knowledge on chromosome aberration induction, both from an experimental and from a theoretical point of view. More specifically, in vitro data will be summarized and discussed, outlining important issues such as the role of interphase death/mitotic delay and that of complex-exchange scoring. Some available in vivo data on cancer patients and astronauts will be also reported, together with possible interpretation problems. Finally, two of the few available models of chromosome aberration induction by ionizing radiation (including heavy ions) will be described and compared, focusing on the different assumptions adopted by the authors and on how these models can deal with heavy ions.

  8. Model of chromosome associations in Mus domesticus spermatocytes

    Directory of Open Access Journals (Sweden)

    Soledad Berríos

    2010-01-01

    Full Text Available Understanding the spatial organization of the chromosomes in meiotic nuclei is crucial to our knowledge of the genome's functional regulation, stability and evolution. This study examined the nuclear architecture of Mus domesticus 2n=40 pachytene spermatocytes, analyzing the associations among autosomal bivalents via their Centromere Telomere Complexes (CTC. The study developed a nuclear model in which each CTC was represented as a 3D computer object. The probability of a given combination of associations among CTC was estimated by simulating a random distribution of 19 indistinguishable CTC over n indistinguishable "cells" on the nuclear envelope. The estimated association frequencies resulting from this numerical approach were similar to those obtained by quantifying actual associations in pachytene spermatocyte spreads. The nuclear localization and associations of CTC through the meiotic prophase in well-preserved nuclei were also analyzed. We concluded that throughout the meiotic prophase: 1 the CTC of autosomal bivalents are not randomly distributed in the nuclear space; 2 the CTC associate amongst themselves, probably at random, over a small surface of the nuclear envelope, at the beginning of the meiotic prophase; 3 the initial aggregation of centromere regions occurring in lepto-zygotene likely resolves into several smaller aggregates according to patterns of preferential partitioning; 4 these smaller aggregates spread over the inner face of the nuclear envelope, remaining stable until advanced stages of the meiotic prophase or even until the first meiotic division.

  9. Familial transmission of a ring chromosome 21

    DEFF Research Database (Denmark)

    Hertz, Jens Michael

    1987-01-01

    A ring chromosome 21 was found in a phenotypically normal mother and her son. The clinical findings in the son were bilateral retention of the testes and a slightly delayed puberty onset. Consequences of a ring formation of a chromosome 21 in phenotypically normal patients are presented...... and discussed, and the previously reported cases of familially transmitted G-group ring chromosomes are reviewed....

  10. High resolution analysis of interphase chromosome domains

    NARCIS (Netherlands)

    Visser, A. E.; Jaunin, F.; Fakan, S.; Aten, J. A.

    2000-01-01

    Chromosome territories need to be well defined at high resolution before functional aspects of chromosome organization in interphase can be explored. To visualize chromosomes by electron microscopy (EM), the DNA of Chinese hamster fibroblasts was labeled in vivo with thymidine analogue BrdU. Labeled

  11. Chromosome number and cytomorphological characterization of a ...

    African Journals Online (AJOL)

    Chromosome counts from natural populations of Abrus pulchellus in Nigeria were carried out. Tetraploid (2n = 44) chromosome number was constant in all the samples investigated. The 44 chromosomes fall into three cytomorphological categories: eight metacentric and eight submetacentric pairs, and six acrocentric pairs.

  12. Chromosome movements promoted by the mitochondrial protein SPD-3 are required for homology search during Caenorhabditis elegans meiosis.

    Directory of Open Access Journals (Sweden)

    Leticia Labrador

    2013-05-01

    Full Text Available Pairing of homologous chromosomes during early meiosis is essential to prevent the formation of aneuploid gametes. Chromosome pairing includes a step of homology search followed by the stabilization of homolog interactions by the synaptonemal complex (SC. These events coincide with dramatic changes in nuclear organization and rapid chromosome movements that depend on cytoskeletal motors and are mediated by SUN-domain proteins on the nuclear envelope, but how chromosome mobility contributes to the pairing process remains poorly understood. We show that defects in the mitochondria-localizing protein SPD-3 cause a defect in homolog pairing without impairing nuclear reorganization or SC assembly, which results in promiscuous installation of the SC between non-homologous chromosomes. Preventing SC assembly in spd-3 mutants does not improve homolog pairing, demonstrating that SPD-3 is required for homology search at the start of meiosis. Pairing center regions localize to SUN-1 aggregates at meiosis onset in spd-3 mutants; and pairing-promoting proteins, including cytoskeletal motors and polo-like kinase 2, are normally recruited to the nuclear envelope. However, quantitative analysis of SUN-1 aggregate movement in spd-3 mutants demonstrates a clear reduction in mobility, although this defect is not as severe as that seen in sun-1(jf18 mutants, which also show a stronger pairing defect, suggesting a correlation between chromosome-end mobility and the efficiency of pairing. SUN-1 aggregate movement is also impaired following inhibition of mitochondrial respiration or dynein knockdown, suggesting that mitochondrial function is required for motor-driven SUN-1 movement. The reduced chromosome-end mobility of spd-3 mutants impairs coupling of SC assembly to homology recognition and causes a delay in meiotic progression mediated by HORMA-domain protein HTP-1. Our work reveals how chromosome mobility impacts the different early meiotic events that promote

  13. Chromosomal Evolution in Lower Vertebrates: Sex Chromosomes in Neotropical Fishes

    Czech Academy of Sciences Publication Activity Database

    Cioffi, M. de B.; Yano, C. F.; Sember, Alexandr; Bertollo, L.A.C.

    2017-01-01

    Roč. 8, č. 10 (2017), č. článku 258. ISSN 2073-4425 R&D Projects: GA MŠk EF15_003/0000460 Institutional support: RVO:67985904 Keywords : alternative evolutionary models * simple and multiple sex chromosomes * independent and common origins Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Genetics and heredity (medical genetics to be 3) Impact factor: 3.600, year: 2016

  14. 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

  15. [Mechanistic modelling allows to assess pathways of DNA lesion interactions underlying chromosome aberration formation].

    Science.gov (United States)

    Eĭdel'man, Iu A; Slanina, S V; Sal'nikov, I V; Andreev, S G

    2012-12-01

    The knowledge of radiation-induced chromosomal aberration (CA) mechanisms is required in many fields of radiation genetics, radiation biology, biodosimetry, etc. However, these mechanisms are yet to be quantitatively characterised. One of the reasons is that the relationships between primary lesions of DNA/chromatin/chromosomes and dose-response curves for CA are unknown because the pathways of lesion interactions in an interphase nucleus are currently inaccessible for direct experimental observation. This article aims for the comparative analysis of two principally different scenarios of formation of simple and complex interchromosomal exchange aberrations: by lesion interactions at chromosome territories' surface vs. in the whole space of the nucleus. The analysis was based on quantitative mechanistic modelling of different levels of structures and processes involved in CA formation: chromosome structure in an interphase nucleus, induction, repair and interactions of DNA lesions. It was shown that the restricted diffusion of chromosomal loci, predicted by computational modelling of chromosome organization, results in lesion interactions in the whole space of the nucleus being impossible. At the same time, predicted features of subchromosomal dynamics agrees well with in vivo observations and does not contradict the mechanism of CA formation at the surface of chromosome territories. On the other hand, the "surface mechanism" of CA formation, despite having certain qualities, proved to be insufficient to explain high frequency of complex exchange aberrations observed by mFISH technique. The alternative mechanism, CA formation on nuclear centres is expected to be sufficient to explain frequent complex exchanges.

  16. Chromosome territories, X;Y translocation and Premature Ovarian Failure: is there a relationship?

    Directory of Open Access Journals (Sweden)

    Betri Enrico

    2009-09-01

    Full Text Available Abstract Background Premature ovarian failure (POF is a secondary hypergonadotrophic amenorrhea occurring before the age of 40 and affecting 1-3% of females. Chromosome anomalies account for 6-8% of POF cases, but only few cases are associated with translocations involving X and Y chromosomes. This study shows the cytogenetic and molecular analysis of a POF patient came to our attention as she developed a left ovary choriocarcinoma at the age of 10 and at 14 years of age she presented secondary amenorrhea with elevated levels of gonadotropins. Results Breakpoint position on X and Y chromosomes was investigated using Fluorescent In Situ Hybridisation (FISH with a panel of specific BAC probes, microsatellite analysis and evaluation of copy number changes and loss of heterozigosity by Affymetrix® GeneChip platform (Santa Clara, CA, USA. Patient's karyotype resulted 46, X, der(Yt(X;Y(q13.1;q11.223. X inactivation study was assessed by RBA banding and showed preferential inactivation of derivative chromosome. The reciprocal spatial disposition of sexual chromosome territories was investigated using whole chromosome painting and centromeres probes: patient's results didn't show a significant difference in comparison to normal controls. Conclusion The peculiar clinical case come to our attention highlighted the complexity of POF aetiology and of the translocation event, even if our results seem to exclude any effect on nuclear organisation. POF phenotype could be partially explained by skewed X chromosome inactivation that influences gene expression.

  17. ISCN rules for listing chromosomal rearrangements.

    Science.gov (United States)

    2001-05-01

    It contains the standard system for numbering human chromosomes and constitutional rearrangements and the banding pattern for normal chromosomes at 400-, 550-, and 850-band levels of resolution. ISCN 1995 also contains guidelines for cancer cytogenetics and for in situ hybridization. The complete ISCN 1995 also contains nomenclature for human meiotic chromosomes (not included here). The guidelines presented herein are recommended for use when reporting karyotypes, designating chromosome rearrangements and aberrations, and indicating regions of the genome where DNA sequences are located. It contains the standard system for numbering human chromosomes and constitutional rearrangements and the banding pattern for.

  18. Effects of antitopoisomerase drugs on chromosome recombinations and segregation in grasshopper

    Energy Technology Data Exchange (ETDEWEB)

    Palitti, F. [Universita degli Studi della Tuscia, Via San Camillo de Lellius (Italy); Motta, S.; Grazioso, C.; Pisano, M.C. [Universita di Catania (Italy)

    1993-12-31

    The role of different cellular functions which are required for the production of euploid cells can be studied through the use of mutants that are defective in the control of both the meiotic and mitotic cell cycle or through the use of compounds which interface with the various cellular targets which have a role in the segregation of chromosomes. The role of the achromatic part of the mitotic apparatus in the production of aneuploidy is well recognized. Substantial progress has been made in understanding the role of the chromatic part, for example, there are observations that disturbances in the normal {open_quotes}metabolism{close_quotes} of the chromosomes (i.e. chromosome condensation, defective DNA repair or recombination) can affect chromosome segregation. Between the processes of both meiosis and mitosis that lead to nuclear division there are, however, important differences.

  19. Nuclear law - Nuclear safety

    International Nuclear Information System (INIS)

    Pontier, Jean-Marie; Roux, Emmanuel; Leger, Marc; Deguergue, Maryse; Vallar, Christian; Pissaloux, Jean-Luc; Bernie-Boissard, Catherine; Thireau, Veronique; Takahashi, Nobuyuki; Spencer, Mary; Zhang, Li; Park, Kyun Sung; Artus, J.C.

    2012-01-01

    This book contains the contributions presented during a one-day seminar. The authors propose a framework for a legal approach to nuclear safety, a discussion of the 2009/71/EURATOM directive which establishes a European framework for nuclear safety in nuclear installations, a comment on nuclear safety and environmental governance, a discussion of the relationship between citizenship and nuclear, some thoughts about the Nuclear Safety Authority, an overview of the situation regarding the safety in nuclear waste burying, a comment on the Nome law with respect to electricity price and nuclear safety, a comment on the legal consequences of the Fukushima accident on nuclear safety in the Japanese law, a presentation of the USA nuclear regulation, an overview of nuclear safety in China, and a discussion of nuclear safety in the medical sector

  20. Dynamics of chromosome segregation in Escherichia coli

    DEFF Research Database (Denmark)

    Nielsen, Henrik Jørck

    2007-01-01

    Since the 1960’es the conformation and segregation of the chromosome in Escherichia coli has been a subject of interest for many scientists. However, after 40 years of research, we still know incredibly little about how the chromosome is organized inside the cell, how it manages to duplicate...... method enabled us to start the analysis on the distribution of various chromosomal loci inside slowly growing cells. With the actual counting and measuring no longer being any problem we could easily analyze 14 loci distributed on the E.coli chromosome. More than 15.000 cells were analyzed in total...... the new system, which is based on the pMT1 par system from Yersenia pestis, we labeled loci on opposite sides of the E.coli chromosome simultaneously and were able to show that the E.coli chromosome is organized with one chromosomal arm in each cell half. This astounding result is described in Paper III...

  1. Chromosome chains and platypus sex: kinky connections.

    Science.gov (United States)

    Ashley, Terry

    2005-07-01

    Mammal sex determination depends on an XY chromosome system, a gene for testis development and a means of activating the X chromosome. The duckbill platypus challenges these dogmas.(1,2) Gutzner et al.(1) find no recognizable SRY sequence and question whether the mammalian X was even the original sex chromosome in the platypus. Instead they suggest that the original platypus sex chromosomes were derived from the ZW chromosome system of birds and reptiles. Unraveling the puzzles of sex determination and dosage compensation in the platypus has been complicated by the fact that it has a surplus of sex chromosomes. Rather than a single X and Y chromosome, the male platypus has five Xs and five Ys. Copyright (c) 2005 Wiley Periodicals, Inc.

  2. Delayed chromosomal instability induced by DNA damage

    International Nuclear Information System (INIS)

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

    1994-01-01

    Cellular exposure to DNA damaging agents rapidly results in a dose dependent increase in chromosomal breakage and gross structural chromosomal rearrangements. Over recent years, evidence has been accumulating indicating genomic instability can manifest multiple generations after cellular exposure to physical and chemical DNA damaging agents. Genomic instability manifests in the progeny of surviving cells, and has been implicated in mutation, gene application, cellular transformation, and cell killing. To investigate chromosome 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 surviving X-irradiation many generations after exposure. At higher radiation doses, chromosomal instability was observed in a relatively high frequency of surviving clones and, in general, those clones showed delayed chromosome instability also showed reduced survival as measured by colony forming ability

  3. Genome Organization Drives Chromosome Fragility.

    Science.gov (United States)

    Canela, Andres; Maman, Yaakov; Jung, Seolkyoung; Wong, Nancy; Callen, Elsa; Day, Amanda; Kieffer-Kwon, Kyong-Rim; Pekowska, Aleksandra; Zhang, Hongliang; Rao, Suhas S P; Huang, Su-Chen; Mckinnon, Peter J; Aplan, Peter D; Pommier, Yves; Aiden, Erez Lieberman; Casellas, Rafael; Nussenzweig, André

    2017-07-27

    In this study, we show that evolutionarily conserved chromosome loop anchors bound by CCCTC-binding factor (CTCF) and cohesin are vulnerable to DNA double strand breaks (DSBs) mediated by topoisomerase 2B (TOP2B). Polymorphisms in the genome that redistribute CTCF/cohesin occupancy rewire DNA cleavage sites to novel loop anchors. While transcription- and replication-coupled genomic rearrangements have been well documented, we demonstrate that DSBs formed at loop anchors are largely transcription-, replication-, and cell-type-independent. DSBs are continuously formed throughout interphase, are enriched on both sides of strong topological domain borders, and frequently occur at breakpoint clusters commonly translocated in cancer. Thus, loop anchors serve as fragile sites that generate DSBs and chromosomal rearrangements. VIDEO ABSTRACT. Published by Elsevier Inc.

  4. Chromosomal instability determines taxane response

    DEFF Research Database (Denmark)

    Swanton, C.; Nicke, B.; Schuett, M.

    2009-01-01

    Microtubule-stabilizing (MTS) agents, such as taxanes, are important chemotherapeutics with a poorly understood mechanism of action. We identified a set of genes repressed in multiple cell lines in response to MTS agents and observed that these genes are overexpressed in tumors exhibiting...... chromosomal instability (CIN). Silencing 22/50 of these genes, many of which are involved in DNA repair, caused cancer cell death, suggesting that these genes are involved in the survival of aneuploid cells. Overexpression of these "CIN-survival'' genes is associated with poor outcome in estrogen receptor......-positive breast cancer and occurs frequently in basal-like and Her2-positive cases. In diploid cells, but not in chromosomally unstable cells, paclitaxel causes repression of CIN-survival genes, followed by cell death. In the OV01 ovarian cancer clinical trial, a high level of CIN was associated with taxane...

  5. Chromosomes aberations and enviromental factors

    Directory of Open Access Journals (Sweden)

    Marković Srđan Z.

    2017-01-01

    Full Text Available Explanation the topic: Changes in genetic material can lead to aberrant cell in the direction of disorders of cellular regulation, malignant transformation, cell death, or if the adjustment was made at the level of the reproductive cells, to genetic changes in some of the consequent off spring. The topic position in scientific/professional public: Breaking of chromosomes can occur spontaneously or can be induced. Chromatid/chromosome breakings can be induced by different environmental factors: chemicals, biological clastogenic agents, accidentally or intentionally. Conclusions: The authors suggest: - making conditions for strong respect of environmental regulations; - to use higher plants for the early detection of environmental mutagens; - create and orderly update National radionuclide database.

  6. 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...

  7. [Chromosome aberrations in malformed newborns].

    Science.gov (United States)

    Centeno Malfaz, F; Beltrán Pérez, A; Ruiz Labarga, C; Centeno Robles, T; Macías Pardal, J; Martín Bermejo, M

    2001-06-01

    To determine the prevalence of chromosome abnormalities in malformed newborn infants and to analyze the distribution of the types of anomalies, and the variation in their frequency with maternal age. We used the data collected according to the Spanish Collaborative Study of Congenital Malformations (ECEMC) methodology from March 1982 -September 1996. Of 33,562 newborns (live and stillborn), 1,409(4.1%) malformed infants were identified. A total of 332 karyotypes were performed in peripheral blood, representing 23.5% of the newborns with congenital defects. Results The frequency at birth of chromosome abnormalities was 5.4% of malformed newborns. There were 59 infants with Down's syndrome, 6 with trisomy 18, 3 with Turner's syndrome, 2 with trisomy 13, 2 with "Triple X", 1 tetraploidy, 1 triploidy, 1 trisomy 9 p, and 1 infant with a complex XXY mosaicism. The prevalence of Down's syndrome in the general population is 0.17%. The mean age of mothers with Down's syndrome infants was 34.2 years and paternal age was 36 years, and a non-statistically significant diminishing trend in mean maternal age was observed during the course of the study. The prevalence of Down's syndrome was higher in mothers aged more than 35 years. A non-statistically significant increase of the prevalence of Down's syndrome in newborns with mothers aged between 31 and 34 years was observed with time. The mean number of previous pregnancies was 2.81. Among a total of 49 mothers and fathers, two chromosome alterations were found. The prevalence of chromosome abnormalities in newborns with birth defects was 5.4%. The frequency of Down's syndrome was higher. Down's syndrome was more prevalent in mothers aged more than 35 years. The mean maternal age of Down's syndrome infants gradually diminished, and accumulated between the ages of 31 and 34 years.

  8. GSK-3 inhibitors induce chromosome instability

    Directory of Open Access Journals (Sweden)

    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.

  9. De Novo Chromosome Structure Prediction

    Science.gov (United States)

    di Pierro, Michele; Cheng, Ryan R.; Lieberman-Aiden, Erez; Wolynes, Peter G.; Onuchic, Jose'n.

    Chromatin consists of DNA and hundreds of proteins that interact with the genetic material. In vivo, chromatin folds into nonrandom structures. The physical mechanism leading to these characteristic conformations, however, remains poorly understood. We recently introduced MiChroM, a model that generates chromosome conformations by using the idea that chromatin can be subdivided into types based on its biochemical interactions. Here we extend and complete our previous finding by showing that structural chromatin types can be inferred from ChIP-Seq data. Chromatin types, which are distinct from DNA sequence, are partially epigenetically controlled and change during cell differentiation, thus constituting a link between epigenetics, chromosomal organization, and cell development. We show that, for GM12878 lymphoblastoid cells we are able to predict accurate chromosome structures with the only input of genomic data. The degree of accuracy achieved by our prediction supports the viability of the proposed physical mechanism of chromatin folding and makes the computational model a powerful tool for future investigations.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    Pita, Sebastián; Panzera, Francisco; Ferrandis, Inés; Galvão, Cleber; Gómez-Palacio, Andrés; Panzera, Yanina

    2013-01-01

    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. PMID:23778665

  12. Genome size and chromosome number of Micromeria acropolitana (Lamiaceae), a steno-endemic of Greece

    DEFF Research Database (Denmark)

    Siljak-Yakovlev, Sonia; Tan, Kit; Tsounis, Gregory

    2011-01-01

    The chromosome number 2n = 30, and nuclear DNA amount 2C = 0.79 pg, are determined for the first time for Micromeria acropolitana, a rare and endangered species from the Acropolis in Athens, Greece. The plant was considered extinct but rediscovered in 2006, a hundred years later. Its current status...

  13. SDR-O: an orphan short-chain dehydrogenase/reductase localized at mouse chromosome 10/human chromosome 12.

    Science.gov (United States)

    Chen, Weiguo; Song, Min-Sun; Napoli, Joseph L

    2002-07-10

    We report cloning a cDNA that encodes a novel short-chain dehydrogenase/reductase, SDR-O, conserved in mouse, human and rat. Human and mouse liver express SDR-O (short-chain dehydrogenase/reductase-orphan) mRNA intensely. The mouse embryo expresses SDR-O mRNA as early as day seven. Human SDR-O localizes on chromosome 12; mouse SDR-O localizes on chromosome 10 with CRAD1, CRAD2 and RDH4. SDR-O shares highest amino acid similarity with rat RoDH1 and mouse RDH1 (69-70%), but does not have the retinol and 3alpha-hydroxysteroid dehydrogenase activity of either, nor is it active as a 17beta- or 11beta-hydroxysteroid dehydrogenase. Short-chain dehydrogenase/reductases catalyse the metabolism of ligands that bind with nuclear receptors: the occurrence of 'orphan' nuclear receptors may imply existence of 'orphan' SDR, suggesting that SDR-O may catalyse the metabolism of another class of nuclear receptor ligand. Alternatively, SDR-O may not have a catalytic function, but may regulate metabolism by binding substrates/products and/or by serving as a regulatory factor.

  14. Meiotic crossing-over in nondisjoined chromosomes of children with trisomy 21 and a congenital heart defect

    Energy Technology Data Exchange (ETDEWEB)

    Howard, C.M.; Davis, G.E.; Farrer, M.J.; Cullen, L.M.; Coleman, M.M.; Williamson, R.; Wyse, R.K.H.; Palmer, R.; Kessling, A.M. (Queen Elizabeth Hospital for Children, London (United Kingdom))

    1993-08-01

    The authors have used DNA polymorphisms to study meiotic crossovers of chromosome 21q in 27 nuclear families. Each family had a child with Down syndrome and a congenital heart defect. Twenty DNA polymorphisms on chromosome 21 were used to determine parental and meiotic origin of nondisjunction and to identify crossovers. Twenty-four cases were of maternal origin, and three were of paternal origin. Twenty-two unequivocal crossover events were identified. Sixteen crossovers were observed in 22 chromosome pairs nondisjoining at the first meiotic division (MI), and six crossovers were observed in five chromosome pairs disjoining at the second meiotic division. Fifty percent of crossover events in MI nondisjunction are detectable by molecular genetic means. Thus, the results suggest that, in this sample, each nondisjoined chromosome 21 pair has been involved in at least one crossover event. 28 refs., 1 fig., 3 tabs.

  15. Doses in radiation accidents investigated by chromosome aberration analysis

    International Nuclear Information System (INIS)

    Lloyd, D.C.; Prosser, J.S.; Moquet, J.E.; Finnon, P.

    1984-03-01

    During 1983, 29 cases of suspected overexposure to ionising radiation were referred to NRPB for investigation by cytogenetic analysis, and the results are presented in this report. Of the 29 cases, 15 were associated with industrial radiography, seven originated from one or other of the major nuclear organisations and the remaining seven were from an institution of research, education or health. In 21 cases no biological indication of overexposure was found, and of the remaining eight the highest positive dose estimate was 0.4 Gy. The chromosome data are compared with information obtained from physical dosimetry, and a brief summary is given of the circumstances of each case. (author)

  16. Micromechanical study of mitotic chromosome structure

    Science.gov (United States)

    Marko, John

    2011-03-01

    Our group has developed micromanipulation techniques for study of the highly compacted mitotic form of chromosome found in eukaryote cells during cell division. Each metaphase chromosome contains two duplicate centimeter-long DNA molecules, folded up by proteins into cylindrical structures several microns in length. Native chromosomes display linear and reversible stretching behavior over a wide range of extensions (up to 5x native length for amphibian chromosomes), described by a Young modulus of about 300 Pa. Studies using DNA-cutting and protein-cutting enzymes have revealed that metaphase chromosomes behave as a network of chromatin fibers held together by protein-based isolated crosslinks. Our results are not consistent with the more classical model of loops of chromatin attached to a protein-based structural organizer or ``scaffold". In short, our experiments indicate that metaphase chromosomes can be considered to be ``gels" of chromatin; the stretching modulus of a whole chromosome is consistent with stretching of the chromatin fibers contained within it. Experiments using topoisomerases suggest that topological constraints may play an appreciable role in confining chromatin in the metaphase chromosome. Finally, recent experiments on human chromosomes will be reviewed, including results of experiments where chromosome-folding proteins are specifically depleted using siRNA methods. Supported by NSF-MCB-1022117, DMR-0715099, PHY-0852130, DMR-0520513, NCI 1U54CA143869-01 (NU-PS-OC), and the American Heart Association.

  17. Chromosome analysis of arsenic affected cattle

    Directory of Open Access Journals (Sweden)

    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.

  18. PREFERENTIAL SEGREGATION OF CHROMOSOMES FROM A TRIVALENT IN HAPLOPAPPUS GRACILIS.

    Science.gov (United States)

    JACKSON, R C

    1964-07-31

    Crosses between plants of Haplopappus gracilis (n = 2) and a race with three pairs of chromosomes (tribivalens) gave a highly fertile five-chromosome hybrid. In both races the chromosomes with the satellites appear homologous, but the other two tribivalens chromosomes pair with the A chromosome (without a satellite) of H. gracilis. Disjunction from the resulting trivalent is preferential: the A chromosome goes to one pole and the two tribivalens chromosomes to the other.

  19. 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.

  20. Deciphering evolutionary strata on plant sex chromosomes and fungal mating-type chromosomes through compositional segmentation.

    Science.gov (United States)

    Pandey, Ravi S; Azad, Rajeev K

    2016-03-01

    Sex chromosomes have evolved from a pair of homologous autosomes which differentiated into sex determination systems, such as XY or ZW system, as a consequence of successive recombination suppression between the gametologous chromosomes. Identifying the regions of recombination suppression, namely, the "evolutionary strata", is central to understanding the history and dynamics of sex chromosome evolution. Evolution of sex chromosomes as a consequence of serial recombination suppressions is well-studied for mammals and birds, but not for plants, although 48 dioecious plants have already been reported. Only two plants Silene latifolia and papaya have been studied until now for the presence of evolutionary strata on their X chromosomes, made possible by the sequencing of sex-linked genes on both the X and Y chromosomes, which is a requirement of all current methods that determine stratum structure based on the comparison of gametologous sex chromosomes. To circumvent this limitation and detect strata even if only the sequence of sex chromosome in the homogametic sex (i.e. X or Z chromosome) is available, we have developed an integrated segmentation and clustering method. In application to gene sequences on the papaya X chromosome and protein-coding sequences on the S. latifolia X chromosome, our method could decipher all known evolutionary strata, as reported by previous studies. Our method, after validating on known strata on the papaya and S. latifolia X chromosome, was applied to the chromosome 19 of Populus trichocarpa, an incipient sex chromosome, deciphering two, yet unknown, evolutionary strata. In addition, we applied this approach to the recently sequenced sex chromosome V of the brown alga Ectocarpus sp. that has a haploid sex determination system (UV system) recovering the sex determining and pseudoautosomal regions, and then to the mating-type chromosomes of an anther-smut fungus Microbotryum lychnidis-dioicae predicting five strata in the non

  1. Scaling Chromosomes for an Evolutionary Karyotype: A Chromosomal Tradeoff between Size and Number across Woody Species.

    Science.gov (United States)

    Liang, Guolu; Chen, Hong

    2015-01-01

    This study aims to examine the expected scaling relationships between chromosome size and number across woody species and to clarify the importance of the scaling for the maintenance of chromosome diversity by analyzing the scaling at the inter- & intra-chromosomal level. To achieve for the goals, chromosome trait data were extracted for 191 woody species (including 56 evergreen species and 135 deciduous species) from the available literature. Cross-species analyses revealed a tradeoff among chromosomes between chromosome size and number, demonstrating there is selective mechanism crossing chromosomes among woody species. And the explanations for the result were presented from intra- to inter-chromosome contexts that the scaling may be compromises among scale symmetry, mechanical requirements, and resource allocation across chromosomes. Therein, a 3/4 scaling pattern was observed between total chromosomes and m-chromosomes within nucleus which may imply total chromosomes may evolve from more to less. In addition, the primary evolutionary trend of karyotype and the role of m-chromosomes in the process of karyotype evolution were also discussed.

  2. Chromosomes

    Science.gov (United States)

    ... Links for Patient Care Education All About the Human Genome Project Fact Sheets Genetic Education Resources for Teachers Genomic Careers National DNA Day Online Education Kit Online Genetics Education ... Subjects Research Informed Consent for Genomics Research Intellectual ...

  3. Poetry in motion: Increased chromosomal mobility after DNA damage.

    Science.gov (United States)

    Smith, Michael J; Rothstein, Rodney

    2017-08-01

    Double-strand breaks (DSBs) are among the most lethal DNA lesions, and a variety of pathways have evolved to manage their repair in a timely fashion. One such pathway is homologous recombination (HR), in which information from an undamaged donor site is used as a template for repair. Although many of the biochemical steps of HR are known, the physical movements of chromosomes that must underlie the pairing of homologous sequence during mitotic DSB repair have remained mysterious. Recently, several groups have begun to use a variety of genetic and cell biological tools to study this important question. These studies reveal that both damaged and undamaged loci increase the volume of the nuclear space that they explore after the formation of DSBs. This DSB-induced increase in chromosomal mobility is regulated by many of the same factors that are important during HR, such as ATR-dependent checkpoint activation and the recombinase Rad51, suggesting that this phenomenon may facilitate the search for homology. In this perspective, we review current research into the mobility of chromosomal loci during HR, as well as possible underlying mechanisms, and discuss the critical questions that remain to be answered. Although we focus primarily on recent studies in the budding yeast, Saccharomyces cerevisiae, examples of experiments performed in higher eukaryotes are also included, which reveal that increased mobility of damaged loci is a process conserved throughout evolution. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Chromosome engineering: power tools for plant genetics.

    Science.gov (United States)

    Chan, Simon W L

    2010-12-01

    The term "chromosome engineering" describes technologies in which chromosomes are manipulated to change their mode of genetic inheritance. This review examines recent innovations in chromosome engineering that promise to greatly increase the efficiency of plant breeding. Haploid Arabidopsis thaliana have been produced by altering the kinetochore protein CENH3, yielding instant homozygous lines. Haploid production will facilitate reverse breeding, a method that downregulates recombination to ensure progeny contain intact parental chromosomes. Another chromosome engineering success is the conversion of meiosis into mitosis, which produces diploid gametes that are clones of the parent plant. This is a key step in apomixis (asexual reproduction through seeds) and could help to preserve hybrid vigor in the future. New homologous recombination methods in plants will potentiate many chromosome engineering applications. Copyright © 2010 Elsevier Ltd. All rights reserved.

  5. Chromosomal rearrangements in Tourette syndrome

    DEFF Research Database (Denmark)

    Bertelsen, Birgitte; Debes, Nanette Mol; Hjermind, Lena E

    2013-01-01

    Tourette syndrome (TS) is a childhood-onset complex neurobiological disorder characterized by a combination of persistent motor and vocal tics and frequent presence of other neuropsychiatric comorbidities. TS shares the fate of other complex disorders, where the genetic etiology is largely unknown...... been an efficient tool for the cloning of disease genes in several Mendelian disorders and in a number of complex disorders. Through cytogenetic investigation of 205 TS patients, we identified three possibly disease-associated chromosome rearrangements rendering this approach relevant in chasing TS...

  6. Advances in plant chromosome genomics

    Czech Academy of Sciences Publication Activity Database

    Doležel, Jaroslav; Vrána, Jan; Cápal, Petr; Kubaláková, Marie; Burešová, Veronika; Šimková, Hana

    2014-01-01

    Roč. 32, č. 1 (2014), s. 122-136 ISSN 0734-9750 R&D Projects: GA ČR GAP501/10/1740; GA ČR GAP501/10/1778; GA ČR GBP501/12/G090; GA MŠk(CZ) LO1204 Grant - others:GA MŠk(CZ) ED0007/01/01 Program:ED Institutional support: RVO:61389030 Keywords : BAC library * Chromosome sorting * Cytogenetics Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 9.015, year: 2014

  7. Abnormal Nuclear Shape in Solid Tumors Reflects Mitotic Instability

    OpenAIRE

    Gisselsson, David; Björk, Jonas; Höglund, Mattias; Mertens, Fredrik; Dal Cin, Paola; Åkerman, Måns; Mandahl, Nils

    2001-01-01

    Abnormalities in nuclear morphology are frequently observed in malignant tissues but the mechanisms behind these phenomena are still poorly understood. In this study, the relation between abnormal nuclear shape and chromosomal instability was explored in short-term tumor cell cultures. Mitotically unstable ring and dicentric chromosomes were identified by fluorescence in situ hybridization at metaphase and subsequently localized in interphase nuclei from five malignant soft tissue tumors. The...

  8. 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)

  9. Evaluation of Chromosomal Abnormalities and Common ...

    African Journals Online (AJOL)

    Evaluation of Chromosomal Abnormalities and Common Trombophilic Mutations in Cases with Recurrent Miscarriage. Ahmet Karatas, Recep Eroz, Mustafa Albayrak, Tulay Ozlu, Bulent Cakmak, Fatih Keskin ...

  10. Chromosomal aberrations in ore miners of Slovakia

    International Nuclear Information System (INIS)

    Beno, M.; Vladar, M.; Nikodemova, D.; Vicanova, M.; Durcik, M.

    1998-01-01

    A pilot study was performed in which the incidence of chromosomal aberrations in lymphocytes of miners in ore mines located in Central Slovakia was monitored and related to lifetime underground radon exposure and to lifetime smoking. The conclusions drawn from the results of the study were as follows: the counts of chromosomal aberrations in lymphocytes of miners were significantly higher than in an age matched control group of white-collar staff; the higher counts of chromosomal aberrations could be ascribed to underground exposure of miners and to smoking; a dependence of chromosomal aberration counts on the exposure to radon could not be assessed. (A.K.)

  11. Death Receptor-Induced Apoptosis Signalling Regulation by Ezrin Is Cell Type Dependent and Occurs in a DISC-Independent Manner in Colon Cancer Cells.

    Science.gov (United States)

    Iessi, Elisabetta; Zischler, Luciana; Etringer, Aurélie; Bergeret, Marion; Morlé, Aymeric; Jacquemin, Guillaume; Morizot, Alexandre; Shirley, Sarah; Lalaoui, Najoua; Elifio-Esposito, Selene L; Fais, Stefano; Garrido, Carmen; Solary, Eric; Micheau, Olivier

    2015-01-01

    Ezrin belongs to the ERM (ezrin-radixin-moesin) protein family and has been demonstrated to regulate early steps of Fas receptor signalling in lymphoid cells, but its contribution to TRAIL-induced cell death regulation in adherent cancer cells remains unknown. In this study we report that regulation of FasL and TRAIL-induced cell death by ezrin is cell type dependant. Ezrin is a positive regulator of apoptosis in T-lymphoma cell line Jurkat, but a negative regulator in colon cancer cells. Using ezrin phosphorylation or actin-binding mutants, we provide evidence that negative regulation of death receptor-induced apoptosis by ezrin occurs in a cytoskeleton- and DISC-independent manner, in colon cancer cells. Remarkably, inhibition of apoptosis induced by these ligands was found to be tightly associated with regulation of ezrin phosphorylation on serine 66, the tumor suppressor gene WWOX and activation of PKA. Deficiency in WWOX expression in the liver cancer SK-HEP1 or the pancreatic Mia PaCa-2 cell lines as well as WWOX silencing or modulation of PKA activation by pharmacological regulators, in the colon cancer cell line SW480, abrogated regulation of TRAIL signalling by ezrin. Altogether our results show that death receptor pro-apoptotic signalling regulation by ezrin can occur downstream of the DISC in colon cancer cells.

  12. Cryo-electron microscopy and single molecule fluorescent microscopy detect CD4 receptor induced HIV size expansion prior to cell entry

    Energy Technology Data Exchange (ETDEWEB)

    Pham, Son [Deakin University, Victoria 3216 (Australia); CSIRO Australian Animal Health Laboratory, Victoria 3220 (Australia); Tabarin, Thibault [ARC Centre of Excellence in Advanced Molecular Imaging, University of New South Wales, New South Wales 3220 (Australia); Garvey, Megan; Pade, Corinna [Deakin University, Victoria 3216 (Australia); CSIRO Australian Animal Health Laboratory, Victoria 3220 (Australia); Rossy, Jérémie [ARC Centre of Excellence in Advanced Molecular Imaging, University of New South Wales, New South Wales 3220 (Australia); Monaghan, Paul; Hyatt, Alex [CSIRO Australian Animal Health Laboratory, Victoria 3220 (Australia); Böcking, Till [ARC Centre of Excellence in Advanced Molecular Imaging, University of New South Wales, New South Wales 3220 (Australia); Leis, Andrew [CSIRO Australian Animal Health Laboratory, Victoria 3220 (Australia); Gaus, Katharina, E-mail: k.gaus@unsw.edu.au [ARC Centre of Excellence in Advanced Molecular Imaging, University of New South Wales, New South Wales 3220 (Australia); Mak, Johnson, E-mail: j.mak@deakin.edu.au [Deakin University, Victoria 3216 (Australia); CSIRO Australian Animal Health Laboratory, Victoria 3220 (Australia)

    2015-12-15

    Viruses are often thought to have static structure, and they only remodel after the viruses have entered target cells. Here, we detected a size expansion of virus particles prior to viral entry using cryo-electron microscopy (cryo-EM) and single molecule fluorescence imaging. HIV expanded both under cell-free conditions with soluble receptor CD4 (sCD4) targeting the CD4 binding site on the HIV-1 envelope protein (Env) and when HIV binds to receptor on cellular membrane. We have shown that the HIV Env is needed to facilitate receptor induced virus size expansions, showing that the ‘lynchpin’ for size expansion is highly specific. We demonstrate that the size expansion required maturation of HIV and an internal capsid core with wild type stability, suggesting that different HIV compartments are linked and are involved in remodelling. Our work reveals a previously unknown event in HIV entry, and we propose that this pre-entry priming process enables HIV particles to facilitate the subsequent steps in infection. - Highlights: • Cell free viruses are able to receive external trigger that leads to apparent size expansion. • Virus envelope and CD4 receptor engagement is the lynchpin of virus size expansion. • Internal capsid organisation can influence receptor mediated virus size expansion. • Pre-existing virus-associated lipid membrane in cell free virus can accommodate the receptor mediated virus size expansion.

  13. Cryo-electron microscopy and single molecule fluorescent microscopy detect CD4 receptor induced HIV size expansion prior to cell entry

    International Nuclear Information System (INIS)

    Pham, Son; Tabarin, Thibault; Garvey, Megan; Pade, Corinna; Rossy, Jérémie; Monaghan, Paul; Hyatt, Alex; Böcking, Till; Leis, Andrew; Gaus, Katharina; Mak, Johnson

    2015-01-01

    Viruses are often thought to have static structure, and they only remodel after the viruses have entered target cells. Here, we detected a size expansion of virus particles prior to viral entry using cryo-electron microscopy (cryo-EM) and single molecule fluorescence imaging. HIV expanded both under cell-free conditions with soluble receptor CD4 (sCD4) targeting the CD4 binding site on the HIV-1 envelope protein (Env) and when HIV binds to receptor on cellular membrane. We have shown that the HIV Env is needed to facilitate receptor induced virus size expansions, showing that the ‘lynchpin’ for size expansion is highly specific. We demonstrate that the size expansion required maturation of HIV and an internal capsid core with wild type stability, suggesting that different HIV compartments are linked and are involved in remodelling. Our work reveals a previously unknown event in HIV entry, and we propose that this pre-entry priming process enables HIV particles to facilitate the subsequent steps in infection. - Highlights: • Cell free viruses are able to receive external trigger that leads to apparent size expansion. • Virus envelope and CD4 receptor engagement is the lynchpin of virus size expansion. • Internal capsid organisation can influence receptor mediated virus size expansion. • Pre-existing virus-associated lipid membrane in cell free virus can accommodate the receptor mediated virus size expansion.

  14. 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

  15. Pathways to doubled haploidy: chromosome doubling during androgenesis.

    Science.gov (United States)

    Seguí-Simarro, J M; Nuez, F

    2008-01-01

    Production of doubled haploid (DH) plants through androgenesis induction is a promising and convenient alternative to conventional selfing techniques for the generation of pure lines for breeding programs. This process comprises two main steps: induction of androgenesis and duplication of the haploid genome. Such duplication is sometimes indirectly induced by the treatments used to promote androgenic development. But usually, an additional step of direct chromosome doubling must be included in the protocol. Duplication of the haploid genome of androgenic individuals has been thought to occur through three mechanisms: endoreduplication, nuclear fusion and c-mitosis. In this review we will revise and analyze the evidences supporting each of the proposed mechanisms and their relevance during androgenesis induction, embryo/callus development and plant regeneration. Special attention will be devoted to nuclear fusion, whose evidences are accumulating in the last years. 2008 S. Karger AG, Basel

  16. Dynein-dependent processive chromosome motions promote homologous pairing in C. elegans meiosis

    Science.gov (United States)

    Wynne, David J.; Rog, Ofer; Carlton, Peter M.

    2012-01-01

    Meiotic chromosome segregation requires homologue pairing, synapsis, and crossover recombination, which occur during meiotic prophase. Telomere-led chromosome motion has been observed or inferred to occur during this stage in diverse species, but its mechanism and function remain enigmatic. In Caenorhabditis elegans, special chromosome regions known as pairing centers (PCs), rather than telomeres, associate with the nuclear envelope (NE) and the microtubule cytoskeleton. In this paper, we investigate chromosome dynamics in living animals through high-resolution four-dimensional fluorescence imaging and quantitative motion analysis. We find that chromosome movement is constrained before meiosis. Upon prophase onset, constraints are relaxed, and PCs initiate saltatory, processive, dynein-dependent motions along the NE. These dramatic motions are dispensable for homologous pairing and continue until synapsis is completed. These observations are consistent with the idea that motions facilitate pairing by enhancing the search rate but that their primary function is to trigger synapsis. This quantitative analysis of chromosome dynamics in a living animal extends our understanding of the mechanisms governing faithful genome inheritance. PMID:22232701

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

    Directory of Open Access Journals (Sweden)

    Marco Di Stefano

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

  18. Chromosomal replicons of higher plants

    International Nuclear Information System (INIS)

    Van't Hof, J.

    1987-01-01

    This brief discussion of replicons of higher plants offers a glimpse into the properties of chromosomal DNA replication. It gives evidence that the S phase of unrelated plant species is comprised of temporally ordered replicon families that increase in number with genome size. This orderly process, which assures a normal inheritance of genetic material to recipient daughter cells, is maintained at the level of replicon clusters by two mutually exclusive mechanisms, one involving the rate at which single replicons replicate their allotment of DNA, and another by means of the tempo-pause. The same two mechanisms are used by cells to alter the pattern of chromosomal DNA replication just prior to and during normal development. Both mechanisms are genetically determined and produce genetic effects when disturbed of disrupted by additional non-conforming DNAs. Further insight into how these two mechanisms operate requires more molecular information about the nature of replicons and the factors that govern when a replicon family replicates. Plant material is a rich and ideal source for this information just awaiting exploitation. 63 refs

  19. Chromosomal replicons of higher plants

    Energy Technology Data Exchange (ETDEWEB)

    Van' t Hof, J.

    1987-03-16

    This brief discussion of replicons of higher plants offers a glimpse into the properties of chromosomal DNA replication. It gives evidence that the S phase of unrelated plant species is comprised of temporally ordered replicon families that increase in number with genome size. This orderly process, which assures a normal inheritance of genetic material to recipient daughter cells, is maintained at the level of replicon clusters by two mutually exclusive mechanisms, one involving the rate at which single replicons replicate their allotment of DNA, and another by means of the tempo-pause. The same two mechanisms are used by cells to alter the pattern of chromosomal DNA replication just prior to and during normal development. Both mechanisms are genetically determined and produce genetic effects when disturbed of disrupted by additional non-conforming DNAs. Further insight into how these two mechanisms operate requires more molecular information about the nature of replicons and the factors that govern when a replicon family replicates. Plant material is a rich and ideal source for this information just awaiting exploitation. 63 refs.

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

    NARCIS (Netherlands)

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

    1987-01-01

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

  1. 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

  2. Variation in nuclear DNA content and chromosome numbers in blueberry

    Science.gov (United States)

    Commercial blueberry production in the U.S. relies on cultivars derived from combinations of different blueberry species. Interspecific hybridization continues to be a vital strategy for blueberry breeding, especially in regards to improving abiotic and biotic stress tolerance to expand the range of...

  3. The X chromosome of monotremes shares a highly conserved region with the eutherian and marsupial X chromosomes despite the absence of X chromosome inactivation

    Energy Technology Data Exchange (ETDEWEB)

    Watson, J.M.; Spencer, J.A.; Graves, J.A.M. (La Trobe Univ., Bundoora, Victoria (Australia)); Riggs, A.D. (Beckman Inst., Duarte, CA (USA))

    1990-09-01

    Eight genes, located on the long arm of the human X chromosome and present on the marsupial X chromosome, were mapped by in situ hybridization to the chromosomes of the platypus Ornithorhynchus anatinus, one of the three species of monotreme mammals. All were located on the X chromosome. The authors conclude that the long arm of the human X chromosome represents a highly conserved region that formed part of the X chromosome in a mammalian ancestor at least 150 million years ago. Since three of these genes are located on the long arm of the platypus X chromosome, which is G-band homologous to the Y chromosome and apparently exempt from X chromosome inactivation, the conservation of this region has evidently not depended on isolation by X-Y chromosome differentiation and X chromosome inactivation.

  4. Nuclear Medicine

    Science.gov (United States)

    ... Parents/Teachers Resource Links for Students Glossary Nuclear Medicine What is nuclear medicine? What are radioactive tracers? ... funded researchers advancing nuclear medicine? What is nuclear medicine? Nuclear medicine is a medical specialty that uses ...

  5. Chromosomal painting and ZW sex chromosomes differentiation in Characidium (Characiformes, Crenuchidae

    Directory of Open Access Journals (Sweden)

    Artoni Roberto F

    2011-07-01

    Full Text Available Abstract Background The Characidium (a Neotropical fish group have a conserved diploid number (2n = 50, but show remarkable differences among species and populations in relation to sex chromosome systems and location of nucleolus organizer regions (NOR. In this study, we isolated a W-specific probe for the Characidium and characterized six Characidium species/populations using cytogenetic procedures. We analyzed the origin and differentiation of sex and NOR-bearing chromosomes by chromosome painting in populations of Characidium to reveal their evolution, phylogeny, and biogeography. Results A W-specific probe for efficient chromosome painting was isolated by microdissection and degenerate oligonucleotide primed-polymerase chain reaction (DOP-PCR amplification of W chromosomes from C. gomesi. The W probe generated weak signals dispersed on the proto sex chromosomes in C. zebra, dispersed signals in both W and Z chromosomes in C. lauroi and, in C. gomesi populations revealed a proximal site on the long arms of the Z chromosome and the entire W chromosome. All populations showed small terminal W probe sites in some autosomes. The 18S rDNA revealed distinctive patterns for each analyzed species/population with regard to proto sex chromosome, sex chromosome pair, and autosome location. Conclusions The results from dual-color fluorescence in situ hybridization (dual-color FISH using W and 18S rDNA probes allowed us to infer the putative evolutionary pathways for the differentiation of sex chromosomes and NORs, from structural rearrangements in a sex proto-chromosome, followed by gene erosion and heterochromatin amplification, morphological differentiation of the sex chromosomal pair, and NOR transposition, giving rise to the distinctive patterns observed among species/populations of Characidium. Biogeographic isolation and differentiation of sex chromosomes seem to have played a major role in the speciation process in this group of fish.

  6. Chromosome studies in Cashew ( Anacardium occidentale L ...

    African Journals Online (AJOL)

    Despite the increased cultivation of cashew as a commodity crop in sub-Sahara Africa, Asia and South America there are few chromosome studies on it. The present study investigates number, structure and behavior of chromosome in cashew populations growing in Nigeria. Cytological examination of these populations ...

  7. 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

  8. How to Protect the Chromosomal Ends?

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 15; Issue 6. How to Protect the Chromosomal Ends? - Telomerase, Chromosome Stability and Aging. Anurag N Paranjape Annapoorni Rangarajan. General Article Volume 15 Issue 6 June 2010 pp 538-547 ...

  9. Familial transmission of a ring chromosome 21

    DEFF Research Database (Denmark)

    Hertz, Jens Michael

    1987-01-01

    A ring chromosome 21 was found in a phenotypically normal mother and her son. The clinical findings in the son were bilateral retention of the testes and a slightly delayed puberty onset. Consequences of a ring formation of a chromosome 21 in phenotypically normal patients are presented...

  10. Translocations used to generate chromosome segment duplications ...

    Indian Academy of Sciences (India)

    Supplementary figure 1. (a–i) Putative novel genes created by the breakpoints. Translocation chromosomes are shown with the translocated segment indicated in red and the untranslocated segments in black or blue. Purple arrows indicate whether the chromosome is a donor (arrow pointing up) or a recipient (arrow ...

  11. Chromosomal evolution and phylogenetic analyses in Tayassu ...

    Indian Academy of Sciences (India)

    The phylogenetic relationships among the tayassuids are unclear and have insti- gated debate over the ... [Adega F., Chaves R. and Guedes-Pinto H. 2007 Chromosomal evolution and phylogenetic analyses in Tayassu pecari and Pecari tajacu. (Tayassuidae): tales ..... Chromosome banding in Amphibia. XXV. Karyotype ...

  12. P chromosomes involved in intergenomic rearrangements of ...

    Indian Academy of Sciences (India)

    2014-04-08

    Apr 8, 2014 ... Total genomic DNA were extracted from young leaves of. Pseudoroegneria spicata (2n = 2x ... ments of Y chromosomes for GISH (a); pAs1 repetitive DNA probe signal is green,. pHvG39 repetitive DNA probe ... 2010). Compared to the other P chromosomes, it is easier to exchange and rearrange for the.

  13. CHROMOSOME STUDY OF SOME GRASSHOPPER SPECIES ...

    African Journals Online (AJOL)

    Hence, this research is aimed at studying the chromosomes of some Ethiopian grasshopper species. The grasshopper specimens used in this study were collected from eight localities in central Ethiopia. The specimens were identified as belonging to two families (Acrididae and Tetrigidae). Chromosome preparations were ...

  14. X-chromosome inactivation and escape

    Indian Academy of Sciences (India)

    2015-11-06

    Nov 6, 2015 ... Abstract. X-chromosome inactivation, which was discovered by Mary Lyon in 1961 results in random silencing of one X chromosome in female mammals. This review is dedicated to Mary Lyon, who passed away last year. She predicted many of the features of X inactivation, for e.g., the existence of an X ...

  15. AFM image of an entire polygene chromosome

    International Nuclear Information System (INIS)

    Li Minqian; Takeuchi; Ikai, A.

    1994-01-01

    The author present AFM images of an entire polygene chromosome of Drosophila for the first time. Comparing with conventional optical microscope, the AFM image of the polygene chromosomes provides much higher resolution and 3-D measurement capability which will lead to finer scale gene mapping and identification

  16. Know Your Chromosomes -R-ES-ONANCE

    Indian Academy of Sciences (India)

    hybrid cells. Each clone of cellsl in the library, would contain only one or a pair of human chromosomes, plus a background of mouse chromosomes. Cell fusions have been carried out not only between human and mouse cells but also between human and. Vani Brahmachari is at the Developmental. Biology and Genetics.

  17. Cat-eye syndrome with unusual marker chromosome probably not chromosome 22.

    Science.gov (United States)

    Rosenfeld, W; Verma, R S; Jhaveri, R C

    1984-05-01

    An unusual supernumerary chromosome with a single satellite on the long arm was found in a child with manifestations of the cat-eye syndrome including apparently low-set and malformed ears, preauricular tags, micrognathia, and imperforate anus. Although G-banding suggested that this extra material was chromosome 22, this was not confirmed by several other banding techniques. After examination of the parents' chromosomes, the nature and origin of this extra chromosome remains obscure. We conclude that patients previously diagnosed as having "partial trisomy 22" with incomplete cat-eye syndrome may have a different chromosome constitution when studied by various banding techniques.

  18. Does radial nuclear organisation influence DNA damage?

    Science.gov (United States)

    Gazave, Elodie; Gautier, Philippe; Gilchrist, Susan; Bickmore, Wendy A

    2005-01-01

    It has been suggested that chromatin at the nuclear periphery could act to shield DNA sequences in the nuclear interior from damage. To test this hypothesis, we have examined the nuclear distribution of sites of DNA repair induced by oxidation or UV-C. We do not detect more damage (repair) at the nuclear periphery than in the nuclear interior. In fact, contrary to the body guard hypothesis, there is an excess of damage detected in the nuclear interior. This is further supported by sequence comparison between genes on human chromosomes 18 or 19, and their counterparts in the chimpanzee. The synonymous substitution rate for genes on chromosome 19, which is located towards the centre of the human nucleus, was higher than that for genes on chromosome 18, which is located at the nuclear periphery. We conclude that chromatin at the periphery of the human nucleus is not able to protect more internally located sequences from damage and mutation. We suggest that features of the chromatin structure, or base composition, of sequences in the nuclear centre make them more susceptible to damage.

  19. Temporal genomic evolution of bird sex chromosomes

    DEFF Research Database (Denmark)

    Wang, Zongji; Zhang, Jilin; Yang, Wei

    2014-01-01

    BACKGROUND: Sex chromosomes exhibit many unusual patterns in sequence and gene expression relative to autosomes. Birds have evolved a female heterogametic sex system (male ZZ, female ZW), through stepwise suppression of recombination between chrZ and chrW. To address the broad patterns and complex...... driving forces of Z chromosome evolution, we analyze here 45 newly available bird genomes and four species' transcriptomes, over their course of recombination loss between the sex chromosomes. RESULTS: We show Z chromosomes in general have a significantly higher substitution rate in introns and synonymous...... ('fast-Z' evolution). And species with a lower level of intronic heterozygosities tend to evolve even faster on the Z chromosome. Further analysis of fast-evolving genes' enriched functional categories and sex-biased expression patterns support that, fast-Z evolution in birds is mainly driven by genetic...

  20. Review of the Y chromosome and hypertension

    Directory of Open Access Journals (Sweden)

    D. Ely

    2000-06-01

    Full Text Available The Y chromosome from spontaneously hypertensive rats (SHR has a locus that raises blood pressure 20-25 mmHg. Associated with the SHR Y chromosome effect is a 4-week earlier pubertal rise of testosterone and dependence upon the androgen receptor for the full blood pressure effect. Several indices of enhanced sympathetic nervous system (SNS activity are also associated with the SHR Y chromosome. Blockade of SNS outflow reduced the blood pressure effect. Salt sensitivity was increased by the Y chromosome as was salt appetite which was SNS dependent. A strong correlation (r = 0.57, P<0.001 was demonstrable between plasma testosterone and angiotensin II. Coronary collagen increased with blood pressure and the presence of the SHR Y chromosome. A promising candidate gene for the Y effect is the Sry locus (testis determining factor, a transcription factor which may also have other functions.

  1. Comparison of mitotic cell death by chromosome fragmentation to premature chromosome condensation

    Directory of Open Access Journals (Sweden)

    Bremer Steven W

    2010-10-01

    Full Text Available Abstract Mitotic cell death is an important form of cell death, particularly in cancer. Chromosome fragmentation is a major form of mitotic cell death which is identifiable during common cytogenetic analysis by its unique phenotype of progressively degraded chromosomes. This morphology however, can appear similar to the morphology of premature chromosome condensation (PCC and thus, PCC has been at times confused with chromosome fragmentation. In this analysis the phenomena of chromosome fragmentation and PCC are reviewed and their similarities and differences are discussed in order to facilitate differentiation of the similar morphologies. Furthermore, chromosome pulverization, which has been used almost synonymously with PCC, is re-examined. Interestingly, many past reports of chromosome pulverization are identified here as chromosome fragmentation and not PCC. These reports describe broad ranging mechanisms of pulverization induction and agree with recent evidence showing chromosome fragmentation is a cellular response to stress. Finally, biological aspects of chromosome fragmentation are discussed, including its application as one form of non-clonal chromosome aberration (NCCA, the driving force of cancer evolution.

  2. Topography of genetic elements of X-chromosome relative to the cell nucleus and to the chromosome X territory determined for human lymphocytes

    Czech Academy of Sciences Publication Activity Database

    Falk, Martin; Lukášová, Emilie; Kozubek, Stanislav; Kozubek, Michal

    2002-01-01

    Roč. 292, 1-2 (2002), s. 13-24 ISSN 0378-1119 R&D Projects: GA AV ČR IBS5004010; GA MZd NC5955; GA ČR GA202/01/0197; GA ČR GA301/01/0186 Institutional research plan: CEZ:AV0Z5004920 Keywords : structure of chromosome X territories * chromatin condensation * nuclear topology Subject RIV: BO - Biophysics Impact factor: 2.778, year: 2002

  3. Invisible nuclear; converting nuclear

    International Nuclear Information System (INIS)

    Park, Jongmoon

    1993-03-01

    This book consists of 14 chapters which are CNN era and big science, from East and West to North and South, illusory nuclear strategy, UN and nuclear arms reduction, management of armaments, advent of petroleum period, the track of nuclear power generation, view of energy, internationalization of environment, the war over water in the Middle East, influence of radiation and an isotope technology transfer and transfer armament into civilian industry, the end of nuclear period and the nuclear Nonproliferation, national scientific and technological power and political organ and executive organ.

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

    Science.gov (United States)

    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.

  5. Using Pulsed-Field Gel Electrophoresis to AnalyzeSchizosaccharomyces pombeChromosomes and Chromosomal Elements.

    Science.gov (United States)

    Pai, Chen-Chun; Walker, Carol; Humphrey, Timothy C

    2018-04-02

    Pulsed field gel electrophoresis (PFGE) uses alternatively oriented pulsed electrical fields to separate large DNA molecules. Here, we describe PFGE protocols and conditions for separating and visualizing chromosomes between 0.5 and 6 Mb (optimal for analyzing the endogenous fission yeast chromosomes of 5.7, 4.6, and 3.5 Mb), and for shorter chromosomal elements of between 50 and 600 kb, such as the 530 kb Ch 16 minichromosome. In addition to determining chromosome size, this technique has a wide range of applications, including determining whether DNA replication or repair is complete, defining the molecular karyotype of cells, analyzing chromosomal rearrangements, assigning genes or constructs to particular chromosomes, and isolating DNA from specific chromosomes. © 2018 Cold Spring Harbor Laboratory Press.

  6. Chromosome differentiation patterns during cichlid fish evolution

    Directory of Open Access Journals (Sweden)

    Nirchio Mauro

    2010-06-01

    Full Text Available Abstract Background Cichlid fishes have been the subject of increasing scientific interest because of their rapid adaptive radiation which has led to an extensive ecological diversity and their enormous importance to tropical and subtropical aquaculture. To increase our understanding of chromosome evolution among cichlid species, karyotypes of one Asian, 22 African, and 30 South American cichlid species were investigated, and chromosomal data of the family was reviewed. Results Although there is extensive variation in the karyotypes of cichlid fishes (from 2n = 32 to 2n = 60 chromosomes, the modal chromosome number for South American species was 2n = 48 and the modal number for the African ones was 2n = 44. The only Asian species analyzed, Etroplus maculatus, was observed to have 46 chromosomes. The presence of one or two macro B chromosomes was detected in two African species. The cytogenetic mapping of 18S ribosomal RNA (18S rRNA gene revealed a variable number of clusters among species varying from two to six. Conclusions The karyotype diversification of cichlids seems to have occurred through several chromosomal rearrangements involving fissions, fusions and inversions. It was possible to identify karyotype markers for the subfamilies Pseudocrenilabrinae (African and Cichlinae (American. The karyotype analyses did not clarify the phylogenetic relationship among the Cichlinae tribes. On the other hand, the two major groups of Pseudocrenilabrinae (tilapiine and haplochromine were clearly discriminated based on the characteristics of their karyotypes. The cytogenetic mapping of 18S ribosomal RNA (18S rRNA gene did not follow the chromosome diversification in the family. The dynamic evolution of the repeated units of rRNA genes generates patterns of chromosomal distribution that do not help follows the phylogenetic relationships among taxa. The presence of B chromosomes in cichlids is of particular interest because they may not be represented in

  7. Genotype-Dependent Difference in 5-HT2C Receptor-Induced Hypolocomotion: Comparison with 5-HT2A Receptor Functional Activity

    Directory of Open Access Journals (Sweden)

    Darya V. Bazovkina

    2015-01-01

    Full Text Available In the present study behavioral effects of the 5-HT2C serotonin receptor were investigated in different mouse strains. The 5-HT2C receptor agonist MK-212 applied intraperitoneally induced significant dose-dependent reduction of distance traveled in the open field test in CBA/Lac mice. This effect was receptor-specific because it was inhibited by the 5-HT2C receptor antagonist RS102221. To study the role of genotype in 5-HT2C receptor-induced hypolocomotion, locomotor activity of seven inbred mouse strains was measured after MK-212 acute treatment. We found that the 5-HT2C receptor stimulation by MK-212 decreased distance traveled in the open field test in CBA/Lac, C57Bl/6, C3H/He, and ICR mice, whereas it failed to affect locomotor activity in DBA/2J, Asn, and Balb/c mice. We also compared the interstrain differences in functional response to 5-HT2C and 5-HT2A receptors activation measured by the quantification of receptor-mediated head-twitches. These experiments revealed significant positive correlation between 5-HT2C and 5-HT2A receptors functional responses for all investigated mouse strains. Moreover, we found that 5-HT2A receptor activation with DOI did not change locomotor activity in CBA/Lac mice. Taken together, our data indicate the implication of 5-HT2C receptors in regulation of locomotor activity and suggest the shared mechanism for functional responses mediated by 5-HT2C and 5-HT2A receptors.

  8. Genotype-Dependent Difference in 5-HT2C Receptor-Induced Hypolocomotion: Comparison with 5-HT2A Receptor Functional Activity.

    Science.gov (United States)

    Bazovkina, Darya V; Kondaurova, Elena M; Naumenko, Vladimir S; Ponimaskin, Evgeni

    2015-01-01

    In the present study behavioral effects of the 5-HT2C serotonin receptor were investigated in different mouse strains. The 5-HT2C receptor agonist MK-212 applied intraperitoneally induced significant dose-dependent reduction of distance traveled in the open field test in CBA/Lac mice. This effect was receptor-specific because it was inhibited by the 5-HT2C receptor antagonist RS102221. To study the role of genotype in 5-HT2C receptor-induced hypolocomotion, locomotor activity of seven inbred mouse strains was measured after MK-212 acute treatment. We found that the 5-HT2C receptor stimulation by MK-212 decreased distance traveled in the open field test in CBA/Lac, C57Bl/6, C3H/He, and ICR mice, whereas it failed to affect locomotor activity in DBA/2J, Asn, and Balb/c mice. We also compared the interstrain differences in functional response to 5-HT2C and 5-HT2A receptors activation measured by the quantification of receptor-mediated head-twitches. These experiments revealed significant positive correlation between 5-HT2C and 5-HT2A receptors functional responses for all investigated mouse strains. Moreover, we found that 5-HT2A receptor activation with DOI did not change locomotor activity in CBA/Lac mice. Taken together, our data indicate the implication of 5-HT2C receptors in regulation of locomotor activity and suggest the shared mechanism for functional responses mediated by 5-HT2C and 5-HT2A receptors.

  9. Chromatid Painting for Chromosomal Inversion Detection, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose the continued development of a novel approach to the detection of chromosomal inversions. Transmissible chromosome aberrations (translocations and...

  10. Chromatid Painting for Chromosomal Inversion Detection, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose a novel approach to the detection of chromosomal inversions. Transmissible chromosome aberrations (translocations and inversions) have profound genetic...

  11. 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...

  12. Cloning, structure, and chromosome localization of the mouse glutaryl-CoA dehydrogenase gene

    Energy Technology Data Exchange (ETDEWEB)

    Koeller, D.M.; DiGiulio, A.; Frerman, F.E. [Univ. of Colorado Health Sciences Center, Denver, CO (United States)] [and others

    1995-08-10

    Glutaryl-CoA dehydrogenase (GCDH) is a nuclear-encoded, mitochondrial matrix enzyme. In humans, deficiency of GCDH leads to glutaric acidemia type I, and inherited disorder of amino acid metabolism characterized by a progressive neurodegenerative disease. In this report we describe the cloning and structure of the mouse GCDH (Gcdh) gene and cDNA and its chromosomal localization. The mouse Gcdh cDNA is 1.75 kb long and contains and open reading frame of 438 amino acids. The amino acid sequences of mouse, human, and pig GCDH are highly conserved. The mouse Gcdh gene contains 11 exons and spans 7 kb of genomic DNA. Gcdh was mapped by backcross analysis to mouse chromosome 8 within a region that is homologous to a region of human chromosome 19, where the human gene was previously mapped. 14 refs., 3 figs.

  13. Nonrandom chromosomal changes in human malignant cells

    Energy Technology Data Exchange (ETDEWEB)

    Rowley, J D

    1977-01-01

    The role of chromosomal changes in human malignant cells has been the subject of much debate. The observation of nonrandom chromosomal changes has become well recognized in chronic myelogenous leukemia, and more recently in acute myelogenous leukemia. In the present report, data are presented on the sites of duplication of chromosome No. 1 in hematologic disorders. Trisomy for region lq25 to lq32 was observed in every one of 34 patients whose cells showed duplication of some part of chromosome No. 1. Adjacent regions lq21 to lq25, and lq32 to lqter, also were trisomic in the majority of patients. Two patients had deletions, one of lq32 to qter, and the other, of lp32 to pter. The sites of chromosomal breaks leading to trisomy differ from those involved in balanced reciprocal translocations. Some of these sites are sometimes, but not always, vulnerable in constitutional chromosomal abnormalities. The nature of the proliferative advantage conferred on myeloid cells by these chromosomal changes is unknown.

  14. [Chromosomal instability in carcinogenesis of cervical cancer.

    Science.gov (United States)

    de Los Santos-Munive, Victoria; Alonso-Avelino, Juan Angel

    2013-01-01

    In order to spot common chromosomal imbalances in early and late lesions of cervical cancer that might be used as progression biomarkers, we made a search of literature in PubMed from 1996 to 2011. The medical subject headings employed were chromosomal alterations, loss of heterozygosis, cervical cancer, cervical tumorigenesis, chromosomal aberrations, cervical intraepithelial neoplasm and low-grade squamous intraepithelial lesion. The common chromosomal imbalances were gains in 8q24 (77.7 %), 20q13 (66.9 %), 3q26 (47.1 %), Xp22 (43.8 %), and 5p15 (60 %), principally. On the other hand, integration of the high-risk human papillomavirus genome into the host chromosome has been associated with the development of neoplasia, but the chromosomal imbalances seem to precede and promote such integration. Chromosomal imbalances in 8q24, 20q13, 3q21-26 and 5p15-Xp22, determined by fluorescent in situ hybridization assay or comparative genomic hybridization assay for early detection of the presence of high-risk human papillomavirus, are promising markers of cervical cancer progression.

  15. Insect sex chromosomes. VI. A presumptive hyperactivation of the male X chromosome in Acheta domesticus (L.).

    Science.gov (United States)

    Rao, S R; Ali, S

    1982-01-01

    The functional status of the X chromosome in Acheta domesticus has been analysed at the whole chromosome level on the basis of (1) 3H-thymidine autoradiography, (2) 5-BrdU/AO fluorescence microscopy (3) in vivo 5-BrdU incorporation and (4) 3H-UdR induced aberrations. The rationale of these techniques in relation to the functional aspect of the X chromosome is that the inactive X chromosome would (1) show asynchrony in DNA synthesis, (2) show differential fluorescence, (3) respond differentially to in vivo 5-BrdU treatment and (4) the active X chromosome would show aberrations when treated with 3H-Uridine. From the results, it appears that the X chromosomes in both male (XO) and female (XX) somatic cells of Acheta are euchromatic (active). Further, the single X in the male is transcriptionally as active as the two X chromosomes in the female. In other words, the single X in the male is hyperactive when compared with the single X in the female. From this it is inferred that the male X chromosome is differentially regulated in order to bring about an equalization of it's gene product(s) to that produced by both Xs in the female. Drosophila melanogaster has a comparable system of dosage compensation. Thus, Acheta is yet another insect showing evidence for an X chromosome regulatory mechanism of dosage compensation. Additionally, it is surmised that sex determination in Acheta is based on an autosomes/X chromosome balance mechanism.

  16. Large-scale reconstruction of 3D structures of human chromosomes from chromosomal contact data.

    Science.gov (United States)

    Trieu, Tuan; Cheng, Jianlin

    2014-04-01

    Chromosomes are not positioned randomly within a nucleus, but instead, they adopt preferred spatial conformations to facilitate necessary long-range gene-gene interactions and regulations. Thus, obtaining the 3D shape of chromosomes of a genome is critical for understanding how the genome folds, functions and how its genes interact and are regulated. Here, we describe a method to reconstruct preferred 3D structures of individual chromosomes of the human genome from chromosomal contact data generated by the Hi-C chromosome conformation capturing technique. A novel parameterized objective function was designed for modeling chromosome structures, which was optimized by a gradient descent method to generate chromosomal structural models that could satisfy as many intra-chromosomal contacts as possible. We applied the objective function and the corresponding optimization method to two Hi-C chromosomal data sets of both a healthy and a cancerous human B-cell to construct 3D models of individual chromosomes at resolutions of 1 MB and 200 KB, respectively. The parameters used with the method were calibrated according to an independent fluorescence in situ hybridization experimental data. The structural models generated by our method could satisfy a high percentage of contacts (pairs of loci in interaction) and non-contacts (pairs of loci not in interaction) and were compatible with the known two-compartment organization of human chromatin structures. Furthermore, structural models generated at different resolutions and from randomly permuted data sets were consistent.

  17. Bird-like sex chromosomes of platypus imply recent origin of mammal sex chromosomes.

    Science.gov (United States)

    Veyrunes, Frédéric; Waters, Paul D; Miethke, Pat; Rens, Willem; McMillan, Daniel; Alsop, Amber E; Grützner, Frank; Deakin, Janine E; Whittington, Camilla M; Schatzkamer, Kyriena; Kremitzki, Colin L; Graves, Tina; Ferguson-Smith, Malcolm A; Warren, Wes; Marshall Graves, Jennifer A

    2008-06-01

    In therian mammals (placentals and marsupials), sex is determined by an XX female: XY male system, in which a gene (SRY) on the Y affects male determination. There is no equivalent in other amniotes, although some taxa (notably birds and snakes) have differentiated sex chromosomes. Birds have a ZW female: ZZ male system with no homology with mammal sex chromosomes, in which dosage of a Z-borne gene (possibly DMRT1) affects male determination. As the most basal mammal group, the egg-laying monotremes are ideal for determining how the therian XY system evolved. The platypus has an extraordinary sex chromosome complex, in which five X and five Y chromosomes pair in a translocation chain of alternating X and Y chromosomes. We used physical mapping to identify genes on the pairing regions between adjacent X and Y chromosomes. Most significantly, comparative mapping shows that, contrary to earlier reports, there is no homology between the platypus and therian X chromosomes. Orthologs of genes in the conserved region of the human X (including SOX3, the gene from which SRY evolved) all map to platypus chromosome 6, which therefore represents the ancestral autosome from which the therian X and Y pair derived. Rather, the platypus X chromosomes have substantial homology with the bird Z chromosome (including DMRT1) and to segments syntenic with this region in the human genome. Thus, platypus sex chromosomes have strong homology with bird, but not to therian sex chromosomes, implying that the therian X and Y chromosomes (and the SRY gene) evolved from an autosomal pair after the divergence of monotremes only 166 million years ago. Therefore, the therian X and Y are more than 145 million years younger than previously thought.

  18. Chromosomal aberrations in benign prostatic hyperplasia patients

    Directory of Open Access Journals (Sweden)

    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.

  19. Nuclear liability - nuclear insurance

    International Nuclear Information System (INIS)

    Roesch, H.

    1981-01-01

    In the fourth concluding article on this subject (following articles in VW 1981 pp. 483, 552 and 629), the author explains procedures, duties and obligations according to the Para. Para. 5, 6 and 7 of the AHBKA. These obligations are to be observed before or after the occurrence of damages. In addition, legal consequences following violations of duties - loss of right - joint, insurance, transfer ban, period for filing suit, duty to notify, 'The German Nuclear Reactor Insurance and Reinsurance Community', the insurance according to the 'General terms and conditions governing the liability insurance of licensed activities involving nuclear fuels and other radioactive substances outside nuclear installations (AHBStr.)', object, beginning and exclusion of coverage, 'Special conditions governing the transport of nuclear fuels according to Para. 25 (2) of the Atomic Energy Law' are attached to the General Terms and Conditions governing the liability insurance of licenced activities involving nuclear fuels and other radioactive substances outside nuclear installations. (HSCH) [de

  20. Genetic and chromosomal effects of ionizing radiation

    International Nuclear Information System (INIS)

    Anon.

    1981-01-01

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

  1. The Role of the CRL4Cdt2 Target Spd1 in Chromosome Segregation in Fission Yeast

    DEFF Research Database (Denmark)

    Landvad, Katrine

    Ddb1, a component of the E3 ubiquitin ligase CRL4Cdt2, is needed for proper chromosome segregation in fission yeast as ddb1 deleted cells show unequal distribution of DNA to daughter cells and sensitivity to the microtubule destabilising drug TBZ. In this study we show that Δddb1 cells have...... increased chromosome loss rates and that the CRL4 receptor protein Cdt2 is regulating Ddb1 activity in chromosome segregation. Furthermore, we show that ddb1 deficiency results in premature disjunction of the sister chromatids and cause a decrease in the levels of cohesion establishment factor Eso1....... Concomitant deletion of spd1, a known target of CRL4Cdt2, substantially reduces the observed defects of the ddb1 single mutant, indicating that degradation of Spd1 is important to ensure proper chromosome segregation. Spd1 is degraded on proliferating cell nuclear antigen (PCNA) and we propose...

  2. Chromosomal abnormalities in patients with sperm disorders

    Directory of Open Access Journals (Sweden)

    L. Y. Pylyp

    2013-02-01

    Full Text Available Chromosomal abnormalities are among the most common genetic causes of spermatogenic disruptions. Carriers of chromosomal abnormalities are at increased risk of infertility, miscarriage or birth of a child with unbalanced karyotype due to the production of unbalanced gametes. The natural selection against chromosomally abnormal sperm usually prevents fertilization with sperm barring in cases of serious chromosomal abnormalities. However, assisted reproductive technologies in general and intracytoplasmic sperm injection in particular, enable the transmission of chromosomal abnormalities to the progeny. Therefore, cytogenetic studies are important in patients with male factor infertility before assisted reproduction treatment. The purpose of the current study was to investigate the types and frequencies of chromosomal abnormalities in 724 patients with infertility and to estimate the risk of chromosomal abnormalities detection in subgroups of patients depending on the severity of spermatogenic disruption, aiming at identifying groups of patients in need of cytogenetic studies. Karyotype analysis was performed in 724 blood samples of men attending infertility clinic. Chromosomal preparation was performed by standard techniques. At least 20 GTG-banded metaphase plates with the resolution from 450 to 750 bands per haploid set were analysed in each case. When chromosomal mosaicism was suspected, this number was increased to 50. Abnormal karyotypes were observed in 48 (6.6% patients, including 67% of autosomal abnormalities and 33% of gonosomal abnormalities. Autosomal abnormalities were represented by structural rearrangements. Reciprocal translocations were the most common type of structural chromosomal abnormalities in the studied group, detected with the frequency of 2.6% (n = 19, followed by Robertsonian translocation, observed with the frequency of 1.2% (n = 9. The frequency of inversions was 0.6% (n = 4. Gonosomal abnormalities included 14 cases

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

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  4. [Nuclear theory

    International Nuclear Information System (INIS)

    Haxton, W.

    1990-01-01

    This report discusses research in nuclear physics. Topics covered in this paper are: symmetry principles; nuclear astrophysics; nuclear structure; quark-gluon plasma; quantum chromodynamics; symmetry breaking; nuclear deformation; and cold fusion

  5. Analysis of unstable chromosome alterations frequency induced by neutron-gamma mixed field radiation

    International Nuclear Information System (INIS)

    Souza, Priscilla L.G.; Brandao, Jose Odinilson de C.; Vale, Carlos H.F.P.; Santos, Joelan A.L.; Vilela, Eudice C.; Lima, Fabiana F.; Calixto, Merilane S.; Santos, Neide

    2009-01-01

    Nowadays monitoring chromosome alterations in peripheral blood lymphocytes have been used to access the radiation absorbed dose in individuals exposed accidental or occupationally to gamma radiation. However there are not many studies based on the effects of mixed field neutron-gamma. The radiobiology of neutrons has great importance because in nuclear factories worldwide there are several hundred thousand individuals monitored as potentially receiving doses of neutron. In this paper it was observed the frequencies of unstable chromosome alterations induced by a gamma-neutron mixed field. Blood was obtained from one healthy donor and exposed to mixed field neutron-gamma sources 241 AmBe (20 Ci) at the Neutron Calibration Laboratory (NCL-CRCN/NE-PE-Brazil). The chromosomes were observed at metaphase, following colcemid accumulation and 1000 well-spread metaphases were analyzed for the presence of chromosome alterations by two experienced scorers. The results suggest that there is the possibility of a directly proportional relationship between absorbed dose of neutron-gamma mixed field radiation and the frequency of unstable chromosome alterations analyzed in this paper. (author)

  6. Extensive duplication of the Wolbachia DNA in chromosome four of Drosophila ananassae.

    Science.gov (United States)

    Klasson, Lisa; Kumar, Nikhil; Bromley, Robin; Sieber, Karsten; Flowers, Melissa; Ott, Sandra H; Tallon, Luke J; Andersson, Siv G E; Dunning Hotopp, Julie C

    2014-12-12

    Lateral gene transfer (LGT) from bacterial Wolbachia endosymbionts has been detected in ~20% of arthropod and nematode genome sequencing projects. Many of these transfers are large and contain a substantial part of the Wolbachia genome. Here, we re-sequenced three D. ananassae genomes from Asia and the Pacific that contain large LGTs from Wolbachia. We find that multiple copies of the Wolbachia genome are transferred to the Drosophila nuclear genome in all three lines. In the D. ananassae line from Indonesia, the copies of Wolbachia DNA in the nuclear genome are nearly identical in size and sequence yielding an even coverage of mapped reads over the Wolbachia genome. In contrast, the D. ananassae lines from Hawaii and India show an uneven coverage of mapped reads over the Wolbachia genome suggesting that different parts of these LGTs are present in different copy numbers. In the Hawaii line, we find that this LGT is underrepresented in third instar larvae indicative of being heterochromatic. Fluorescence in situ hybridization of mitotic chromosomes confirms that the LGT in the Hawaii line is heterochromatic and represents ~20% of the sequence on chromosome 4 (dot chromosome, Muller element F). This collection of related lines contain large lateral gene transfers composed of multiple Wolbachia genomes that constitute >2% of the D. ananassae genome (~5 Mbp) and partially explain the abnormally large size of chromosome 4 in D. ananassae.

  7. On the origin of crossover interference: A chromosome oscillatory movement (COM model

    Directory of Open Access Journals (Sweden)

    Hultén Maj A

    2011-04-01

    Full Text Available Abstract Background It is now nearly a century since it was first discovered that crossovers between homologous parental chromosomes, originating at the Prophase stage of Meiosis I, are not randomly placed. In fact, the number and distribution of crossovers are strictly regulated with crossovers/chiasmata formed in optimal positions along the length of individual chromosomes, facilitating regular chromosome segregation at the first meiotic division. In spite of much research addressing this question, the underlying mechanism(s for the phenomenon called crossover/chiasma interference is/are still unknown; and this constitutes an outstanding biological enigma. Results The Chromosome Oscillatory Movement (COM model for crossover/chiasma interference implies that, during Prophase of Meiosis I, oscillatory movements of the telomeres (attached to the nuclear membrane and the kinetochores (within the centromeres create waves along the length of chromosome pairs (bivalents so that crossing-over and chiasma formation is facilitated by the proximity of parental homologs induced at the nodal regions of the waves thus created. This model adequately explains the salient features of crossover/chiasma interference, where (1 there is normally at least one crossover/chiasma per bivalent, (2 the number is correlated to bivalent length, (3 the positions are dependent on the number per bivalent, (4 interference distances are on average longer over the centromere than along chromosome arms, and (5 there are significant changes in carriers of structural chromosome rearrangements. Conclusions The crossover/chiasma frequency distribution in humans and mice with normal karyotypes as well as in carriers of structural chromosome rearrangements are those expected on the COM model. Further studies are underway to analyze mechanical/mathematical aspects of this model for the origin of crossover/chiasma interference, using string replicas of the homologous chromosomes at the

  8. Sister chromatid cohesion defects are associated with chromosome instability in Hodgkin lymphoma cells

    International Nuclear Information System (INIS)

    Sajesh, Babu V; Lichtensztejn, Zelda; McManus, Kirk J

    2013-01-01

    Chromosome instability manifests as an abnormal chromosome complement and is a pathogenic event in cancer. Although a correlation between abnormal chromosome numbers and cancer exist, the underlying mechanisms that cause chromosome instability are poorly understood. Recent data suggests that aberrant sister chromatid cohesion causes chromosome instability and thus contributes to the development of cancer. Cohesion normally functions by tethering nascently synthesized chromatids together to prevent premature segregation and thus chromosome instability. Although the prevalence of aberrant cohesion has been reported for some solid tumors, its prevalence within liquid tumors is unknown. Consequently, the current study was undertaken to evaluate aberrant cohesion within Hodgkin lymphoma, a lymphoid malignancy that frequently exhibits chromosome instability. Using established cytogenetic techniques, the prevalence of chromosome instability and aberrant cohesion was examined within mitotic spreads generated from five commonly employed Hodgkin lymphoma cell lines (L-1236, KM-H2, L-428, L-540 and HDLM-2) and a lymphocyte control. Indirect immunofluorescence and Western blot analyses were performed to evaluate the localization and expression of six critical proteins involved in the regulation of sister chromatid cohesion. We first confirmed that all five Hodgkin lymphoma cell lines exhibited chromosome instability relative to the lymphocyte control. We then determined that each Hodgkin lymphoma cell line exhibited cohesion defects that were subsequently classified into mild, moderate or severe categories. Surprisingly, ~50% of the mitotic spreads generated from L-540 and HDLM-2 harbored cohesion defects. To gain mechanistic insight into the underlying cause of the aberrant cohesion we examined the localization and expression of six critical proteins involved in cohesion. Although all proteins produced the expected nuclear localization pattern, striking differences in RAD21

  9. 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.

  10. Conservation of sex chromosomes in lacertid lizards

    Czech Academy of Sciences Publication Activity Database

    Rovatsos, M.; Vukič, J.; Altmanová, M.; Johnson Pokorná, Martina; Moravec, J.; Kratochvíl, L.

    2016-01-01

    Roč. 25, č. 13 (2016), s. 3120-3126 ISSN 0962-1083 Institutional support: RVO:67985904 Keywords : lizards * molecular sex ing * reptiles * sex chromosomes Subject RIV: EG - Zoology Impact factor: 6.086, year: 2016

  11. The Barley Chromosome 5 Linkage Map

    DEFF Research Database (Denmark)

    Jensen, J.; Jørgensen, Jørgen Helms

    1975-01-01

    The literature is surveyed for data on recombination between loci on chromosome 5 of barley; 13 loci fall into the category “mapped” loci, more than 20 into the category “associated” loci and nine into the category “loci once suggested to be on chromosome 5”. A procedure was developed for estimat......The literature is surveyed for data on recombination between loci on chromosome 5 of barley; 13 loci fall into the category “mapped” loci, more than 20 into the category “associated” loci and nine into the category “loci once suggested to be on chromosome 5”. A procedure was developed...... data are utilized jointly, and (3) omission of inconsistent data and determination of the most likely order of the loci. This procedure was applied to the 42 recombination percentages available for the 13 “mapped” loci. Due to inconsistencies 14 of the recombination percentages and, therefore, two...

  12. Chromosomal contact permits transcription between coregulated genes

    CSIR Research Space (South Africa)

    Fanucchi, Stephanie

    2013-10-01

    Full Text Available Transcription of coregulated genes occurs in the context of long-range chromosomal contacts that form multigene complexes. Such contacts and transcription are lost in knockout studies of transcription factors and structural chromatin proteins...

  13. Histone modifications: Cycling with chromosomal replication

    DEFF Research Database (Denmark)

    Thon, Genevieve

    2008-01-01

    Histone modifications tend to be lost during chromosome duplication. Several recent studies suggest that the RNA interference pathway becomes active during the weakened transcriptional repression occurring at centromeres in S phase, resulting in the re-establishment of histone modifications...

  14. System for the analysis of plant chromosomes

    International Nuclear Information System (INIS)

    Medina Martin, D.; Peraza Gonzalez, L.H.

    1996-01-01

    The paper describes a computer system for the automation workers of recognition analysis and interpretation of plant chromosomes. This system permit to carry out the analysis in a more comfortable and faster way, using the image processing techniques

  15. Genetics Home Reference: Y chromosome infertility

    Science.gov (United States)

    ... chromosomal abnormalities in 2078 infertile couples referred for assisted reproductive techniques. Hum Reprod. 2005 Feb;20(2):437-42. ... Yq microdeletions in infertile italian couples referred for assisted reproductive technique. Sex Dev. 2007;1(6):347-52. doi: ...

  16. Cognitive and medical features of chromosomal aneuploidy.

    Science.gov (United States)

    Hutaff-Lee, Christa; Cordeiro, Lisa; Tartaglia, Nicole

    2013-01-01

    This chapter describes the physical characteristics, medical complications, and cognitive and psychological profiles that are associated with chromosomal aneuploidy conditions, a group of conditions in which individuals are born with one or more additional chromosome. Overall, chromosomal aneuploidy conditions occur in approximately 1 in 250 children. Information regarding autosomal disorders including trisomy 21 (Down syndrome), trisomy 13 (Patau syndrome), and trisomy 18 (Edward syndrome) are presented. Sex chromosome aneuploidy conditions such as Klinefelter syndrome (47,XXY), XYY, trisomy X, and Turner syndrome (45,X), in addition to less frequently occurring tetrasomy and pentasomy conditions are also covered. Treatment recommendations and suggestions for future research directions are discussed. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. Errata :Chromosomal Abnormalities in Couples with Recurrent ...

    African Journals Online (AJOL)

    Chromosomal Abnormalities in Couples with Recurrent Abortions in Lagos, Nigeria. Akinde OR, Daramola A O, Taiwo I A, Afolayan M O and Akinsola Af. Sonographic Mammary Gland Density Pattern in Women in Selected ommunities of Southern Nigeria.

  18. Progression in nuclear classification

    International Nuclear Information System (INIS)

    Wang Yuying

    1999-01-01

    In this book, summarize the author's achievements of nuclear classification by new method in latest 30 years, new foundational law of nuclear layer in matter world is found. It is explained with a hypothesis of a nucleus which it is made up of two nucleon's clusters with deuteron and triton. Its concrete content is: to advance a new method which analyze data of nuclei with natural abundance using relationship between the numbers of proton and neutron. The relationship of each nucleus increases to 4 sets: S+H=Z H+Z=N Z+N=A and S-H=K. To expand the similarity between proton and neutron to the similarity among p,n, deuteron, triton, and He-5 clusters. According to the distribution law of same kind of nuclei, it obtains that the upper limits of stable region both should be '44s'. New foundational law of nuclear system is 1,2,4,8,16,8,4,2,1. In order to explain new law, a hypothesis which nucleus is made up of deuteron and triton is developing and nuclear field of whole number is built up. And it relates that unity of matter motion, which is the most foundational form atomic nuclear systematic is similar to the most first-class form chromosome numbers of mankind. These achievements will shake the foundations of traditional nuclear science. These achievements will supply new tasks in developing nuclear theory. And shake the ground of which magic number is the basic of nuclear science. It opens up a new field on foundational research. The book will supply new knowledge for researcher, teachers and students in universities and polytechnic schools. Scientific workers read in works of research and technical exploit. It can be stored up for library and laboratory of society and universities. In nowadays of prosperity our nation by science and education, the book is readable for workers of scientific technology and amateurs of natural science

  19. Plasmid and chromosome segregation in prokaryotes

    DEFF Research Database (Denmark)

    Møller-Jensen, Jakob; Bugge Jensen, Rasmus; Gerdes, Kenn

    2000-01-01

    Recent major advances in the understanding of prokaryotic DNA segregation have been achieved by using fluorescence microscopy to visualize the localization of cellular components. Plasmids and bacterial chromosomes are partitioned in a highly dynamic fashion, suggesting the presence of a mitotic......-like apparatus in prokaryotes. The identification of chromosomal homologues of the well-characterized plasmid partitioning genes indicates that there could be a general mechanism of bacterial DNA partitioning. Udgivelsesdato: July 1...

  20. Y Chromosome Regulation of Autism Susceptibility Genes

    Science.gov (United States)

    2009-06-01

    autistic children. Such distorted ratio could be as high as 8:1 in some populations [12, 13]. Sexual dimorphism in autism is a key and consistent... autism [18-24]. Recent studies in our laboratory suggest that genes on the Y chromosome could contribute to such sexual dimorphisms, thereby raising the...contribute to autism susceptibility, have provided a critical clue that the male-only chromosome is potentially a key player in the sexual dimorphism

  1. Chromosome evolution in Cophomantini (Amphibia, Anura, Hylinae).

    Science.gov (United States)

    Ferro, Juan M; Cardozo, Dario E; Suárez, Pablo; Boeris, Juan M; Blasco-Zúñiga, Ailin; Barbero, Gastón; Gomes, Anderson; Gazoni, Thiago; Costa, William; Nagamachi, Cleusa Y; Rivera, Miryan; Parise-Maltempi, Patricia P; Wiley, John E; Pieczarka, Julio C; Haddad, Celio F B; Faivovich, Julián; Baldo, Diego

    2018-01-01

    The hylid tribe Cophomantini is a diverse clade of Neotropical treefrogs composed of the genera Aplastodiscus, Boana, Bokermannohyla, Hyloscirtus, and Myersiohyla. The phylogenetic relationships of Cophomantini have been comprehensively reviewed in the literature, providing a suitable framework for the study of chromosome evolution. Employing different banding techniques, we studied the chromosomes of 25 species of Boana and 3 of Hyloscirtus; thus providing, for the first time, data for Hyloscirtus and for 15 species of Boana. Most species showed karyotypes with 2n = 2x = 24 chromosomes; some species of the B. albopunctata group have 2n = 2x = 22, and H. alytolylax has 2n = 2x = 20. Karyotypes are all bi-armed in most species presented, with the exception of H. larinopygion (FN = 46) and H. alytolylax (FN = 38), with karyotypes that have a single pair of small telocentric chromosomes. In most species of Boana, NORs are observed in a single pair of chromosomes, mostly in the small chromosomes, although in some species of the B. albopunctata, B. pulchella, and B. semilineata groups, this marker occurs on the larger pairs 8, 1, and 7, respectively. In Hyloscirtus, NOR position differs in the three studied species: H. alytolylax (4p), H. palmeri (4q), and H. larinopygion (1p). Heterochromatin is a variable marker that could provide valuable evidence, but it would be necesserary to understand the molecular composition of the C-bands that are observed in different species in order to test its putative homology. In H. alytolylax, a centromeric DAPI+ band was observed on one homologue of chromosome pair 2. The band was present in males but absent in females, providing evidence for an XX/XY sex determining system in this species. We review and discuss the importance of the different chromosome markers (NOR position, C-bands, and DAPI/CMA3 patterns) for their impact on the taxonomy and karyotype evolution in Cophomantini.

  2. Chromosome evolution in Cophomantini (Amphibia, Anura, Hylinae)

    Science.gov (United States)

    Suárez, Pablo; Boeris, Juan M.; Blasco-Zúñiga, Ailin; Barbero, Gastón; Gomes, Anderson; Gazoni, Thiago; Costa, William; Nagamachi, Cleusa Y.; Rivera, Miryan; Parise-Maltempi, Patricia P.; Wiley, John E.; Pieczarka, Julio C.; Haddad, Celio F. B.; Faivovich, Julián; Baldo, Diego

    2018-01-01

    The hylid tribe Cophomantini is a diverse clade of Neotropical treefrogs composed of the genera Aplastodiscus, Boana, Bokermannohyla, Hyloscirtus, and Myersiohyla. The phylogenetic relationships of Cophomantini have been comprehensively reviewed in the literature, providing a suitable framework for the study of chromosome evolution. Employing different banding techniques, we studied the chromosomes of 25 species of Boana and 3 of Hyloscirtus; thus providing, for the first time, data for Hyloscirtus and for 15 species of Boana. Most species showed karyotypes with 2n = 2x = 24 chromosomes; some species of the B. albopunctata group have 2n = 2x = 22, and H. alytolylax has 2n = 2x = 20. Karyotypes are all bi-armed in most species presented, with the exception of H. larinopygion (FN = 46) and H. alytolylax (FN = 38), with karyotypes that have a single pair of small telocentric chromosomes. In most species of Boana, NORs are observed in a single pair of chromosomes, mostly in the small chromosomes, although in some species of the B. albopunctata, B. pulchella, and B. semilineata groups, this marker occurs on the larger pairs 8, 1, and 7, respectively. In Hyloscirtus, NOR position differs in the three studied species: H. alytolylax (4p), H. palmeri (4q), and H. larinopygion (1p). Heterochromatin is a variable marker that could provide valuable evidence, but it would be necesserary to understand the molecular composition of the C-bands that are observed in different species in order to test its putative homology. In H. alytolylax, a centromeric DAPI+ band was observed on one homologue of chromosome pair 2. The band was present in males but absent in females, providing evidence for an XX/XY sex determining system in this species. We review and discuss the importance of the different chromosome markers (NOR position, C-bands, and DAPI/CMA3 patterns) for their impact on the taxonomy and karyotype evolution in Cophomantini. PMID:29444174

  3. Antibodies against chromosomal beta-lactamase

    DEFF Research Database (Denmark)

    Giwercman, B; Rasmussen, J W; Ciofu, Oana

    1994-01-01

    A murine monoclonal anti-chromosomal beta-lactamase antibody was developed and an immunoblotting technique was used to study the presence of serum and sputum antibodies against Pseudomonas aeruginosa chromosomal group 1 beta-lactamase in patients with cystic fibrosis (CF). The serum antibody resp...... against the infection. On the other hand, immune complexes between the beta-lactamase and corresponding antibodies could play a role in the pathogenesis of bronchopulmonary injury in CF by mediating hyperimmune reactions....

  4. Demasculinization of the Anopheles gambiae X chromosome

    Directory of Open Access Journals (Sweden)

    Magnusson Kalle

    2012-05-01

    Full Text Available Abstract Background In a number of organisms sex-biased genes are non-randomly distributed between autosomes and the shared sex chromosome X (or Z. Studies on Anopheles gambiae have produced conflicting results regarding the underrepresentation of male-biased genes on the X chromosome and it is unclear to what extent sexual antagonism, dosage compensation or X-inactivation in the male germline, the evolutionary forces that have been suggested to affect the chromosomal distribution of sex-biased genes, are operational in Anopheles. Results We performed a meta-analysis of sex-biased gene expression in Anopheles gambiae which provides evidence for a general underrepresentation of male-biased genes on the X-chromosome that increased in significance with the observed degree of sex-bias. A phylogenomic comparison between Drosophila melanogaster, Aedes aegypti and Culex quinquefasciatus also indicates that the Anopheles X chromosome strongly disfavours the evolutionary conservation of male-biased expression and that novel male-biased genes are more likely to arise on autosomes. Finally, we demonstrate experimentally that transgenes situated on the Anopheles gambiae X chromosome are transcriptionally silenced in the male germline. Conclusion The data presented here support the hypothesis that the observed demasculinization of the Anopheles X chromosome is driven by X-chromosome inactivation in the male germline and by sexual antagonism. The demasculinization appears to be the consequence of a loss of male-biased expression, rather than a failure in the establishment or the extinction of male-biased genes.

  5. Chromosomal organization and segregation in Pseudomonas aeruginosa.

    Directory of Open Access Journals (Sweden)

    Isabelle Vallet-Gely

    2013-05-01

    Full Text Available The study of chromosomal organization and segregation in a handful of bacteria has revealed surprising variety in the mechanisms mediating such fundamental processes. In this study, we further emphasized this diversity by revealing an original organization of the Pseudomonas aeruginosa chromosome. We analyzed the localization of 20 chromosomal markers and several components of the replication machinery in this important opportunistic γ-proteobacteria pathogen. This technique allowed us to show that the 6.3 Mb unique circular chromosome of P. aeruginosa is globally oriented from the old pole of the cell to the division plane/new pole along the oriC-dif axis. The replication machinery is positioned at mid-cell, and the chromosomal loci from oriC to dif are moved sequentially to mid-cell prior to replication. The two chromosomal copies are subsequently segregated at their final subcellular destination in the two halves of the cell. We identified two regions in which markers localize at similar positions, suggesting a bias in the distribution of chromosomal regions in the cell. The first region encompasses 1.4 Mb surrounding oriC, where loci are positioned around the 0.2/0.8 relative cell length upon segregation. The second region contains at least 800 kb surrounding dif, where loci show an extensive colocalization step following replication. We also showed that disrupting the ParABS system is very detrimental in P. aeruginosa. Possible mechanisms responsible for the coordinated chromosomal segregation process and for the presence of large distinctive regions are discussed.

  6. Chromosomal profile of indigenous pig (Sus scrofa

    Directory of Open Access Journals (Sweden)

    P. Guru Vishnu

    2015-02-01

    Full Text Available Aim: The objective of this study was to investigate the chromosomal profile of indigenous pigs by computing morphometric measurements. Materials and Methods: A cytogenetic study was carried out in 60 indigenous pigs to analyze the chromosomal profile by employing the short term peripheral blood lymphocyte culture technique. Results: The modal chromosome number (2n in indigenous pigs was found to be 38 and a fundamental number of 64 as in the exotic. First chromosome was the longest pair, and thirteenth pair was the second largest while Y-chromosome was the smallest in the karyotype of the pig. The mean relative length, arm ratio, centromeric indices and morphological indices of chromosomes varied from 1.99±0.01 to 11.23±0.09, 1.04±0.05 to 2.95±0.02, 0.51±0.14 to 0.75±0.09 and 2.08±0.07 to 8.08±0.15%, respectively in indigenous pigs. Sex had no significant effect (p>0.05 on all the morphometric measurements studied. Conclusion: The present study revealed that among autosomes first five pairs were sub metacentric, next two pairs were sub telocentric (6-7, subsequent five pairs were metacentric (8-12 and remaining six pairs were telocentric (13-18, while both allosomes were metacentric. The chromosomal number, morphology and various morphometric measurements of the chromosomes of the indigenous pigs were almost similar to those established breeds reported in the literature.

  7. Chromosomal evolution in the plant family Solanaceae.

    Science.gov (United States)

    Wu, Feinan; Tanksley, Steven D

    2010-03-17

    Over the past decades, extensive comparative mapping research has been performed in the plant family Solanaceae. The recent identification of a large set of single-copy conserved orthologous (COSII) markers has greatly accelerated comparative mapping studies among major solanaceous species including tomato, potato, eggplant, pepper and diploid Nicotiana species (as well as tetraploid tobacco). The large amount of comparative data now available for these species provides the opportunity to describe the overall patterns of chromosomal evolution in this important plant family. The results of this investigation are described herein. We combined data from multiple COSII studies, and other comparative mapping studies performed in tomato, potato, eggplant, pepper and diploid Nicotiana species, to deduce the features and outcomes of chromosomal evolution in the Solanaceae over the past 30 million years. This includes estimating the rates and timing of chromosomal changes (inversions and translocations) as well as deducing the age of ancestral progenitor species and predicting their genome configurations. The Solanaceae has experienced chromosomal changes at a modest rate compared with other families and the rates are likely conserved across different lineages of the family. Chromosomal inversions occur at a consistently higher rate than do translocations. Further, we find evidences for non-random positioning of the chromosomal rearrangement breakpoints. This finding is consistent with the similar finding in mammals, where hot spots for chromosomal breakages have apparently played a significant role in shaping genome evolution. Finally, by utilizing multiple genome comparisons we were able to reconstruct the most likely genome configuration for a number of now-extinct progenitor species that gave rise to the extant solanaceous species used in this research. The results from this study provide the first broad overview of chromosomal evolution in the family Solanaceae, and

  8. Abnormal sex chromosome constitution and longitudinal growth

    DEFF Research Database (Denmark)

    Aksglaede, Lise; Skakkebaek, Niels E; Juul, Anders

    2008-01-01

    Growth is a highly complex process regulated by the interaction between sex steroids and the GH IGF-axis. However, other factors such as sex chromosome-related genes play independent roles.......Growth is a highly complex process regulated by the interaction between sex steroids and the GH IGF-axis. However, other factors such as sex chromosome-related genes play independent roles....

  9. Female meiotic sex chromosome inactivation in chicken.

    Directory of Open Access Journals (Sweden)

    Sam Schoenmakers

    2009-05-01

    Full Text Available During meiotic prophase in male mammals, the heterologous X and Y chromosomes remain largely unsynapsed, and meiotic sex chromosome inactivation (MSCI leads to formation of the transcriptionally silenced XY body. In birds, the heterogametic sex is female, carrying Z and W chromosomes (ZW, whereas males have the homogametic ZZ constitution. During chicken oogenesis, the heterologous ZW pair reaches a state of complete heterologous synapsis, and this might enable maintenance of transcription of Z- and W chromosomal genes during meiotic prophase. Herein, we show that the ZW pair is transiently silenced, from early pachytene to early diplotene using immunocytochemistry and gene expression analyses. We propose that ZW inactivation is most likely achieved via spreading of heterochromatin from the W on the Z chromosome. Also, persistent meiotic DNA double-strand breaks (DSBs may contribute to silencing of Z. Surprisingly, gammaH2AX, a marker of DSBs, and also the earliest histone modification that is associated with XY body formation in mammalian and marsupial spermatocytes, does not cover the ZW during the synapsed stage. However, when the ZW pair starts to desynapse, a second wave of gammaH2AX accumulates on the unsynapsed regions of Z, which also show a reappearance of the DSB repair protein RAD51. This indicates that repair of meiotic DSBs on the heterologous part of Z is postponed until late pachytene/diplotene, possibly to avoid recombination with regions on the heterologously synapsed W chromosome. Two days after entering diplotene, the Z looses gammaH2AX and shows reactivation. This is the first report of meiotic sex chromosome inactivation in a species with female heterogamety, providing evidence that this mechanism is not specific to spermatogenesis. It also indicates the presence of an evolutionary force that drives meiotic sex chromosome inactivation independent of the final achievement of synapsis.

  10. An anaphase calcium signal controls chromosome disjunction in early sea urchin embryos.

    Science.gov (United States)

    Groigno, L; Whitaker, M

    1998-01-23

    A transient increase in intracellular calcium concentration [Ca2+]i occurs throughout the cell as sea urchin embryos enter anaphase of the first cell cycle. The transient just precedes chromatid disjunction and spindle elongation. Microinjection of calcium chelators or heparin, an InsP3 receptor antagonist, blocks chromosome separation. Photorelease of calcium or InsP3 can reverse the block. Nuclear reformation is merely delayed by calcium antagonists at concentrations that block chromatid separation. Thus, the calcium signal triggers the separation of chromatids, while calcium-independent pathways can bring about the alterations in microtubule dynamics and nuclear events associated with anaphase progression. That calcium triggers chromosome disjunction alone is unexpected. It helps explain previous conflicting results and allows the prediction that calcium plays a similar role at anaphase in other cell types.

  11. 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.

  12. 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.

  13. Neo-sex chromosomes of Ronderosia bergi: insight into the evolution of sex chromosomes in grasshoppers.

    Science.gov (United States)

    Palacios-Gimenez, O M; Marti, D A; Cabral-de-Mello, D C

    2015-09-01

    Sex chromosomes have evolved many times from morphologically identical autosome pairs, most often presenting several recombination suppression events, followed by accumulation of repetitive DNA sequences. In Orthoptera, most species have an X0♂ sex chromosome system. However, in the subfamily Melanoplinae, derived variants of neo-sex chromosomes (neo-XY♂ or neo-X1X2Y♂) emerged several times. Here, we examined the differentiation of neo-sex chromosomes in a Melanoplinae species with a neo-XY♂/XX♀ system, Ronderosia bergi, using several approaches: (i) classical cytogenetic analysis, (ii) mapping via fluorescent in situ hybridization of some selected repetitive DNA sequences and microdissected sex chromosomes, and (iii) immunolocalization of distinct histone modifications. The microdissected sex chromosomes were also used as sources for Polymerase chain reaction (PCR) amplification of RNA-coding multigene families, to study variants related to the sex chromosomes. Our data suggest that the R. bergi neo-Y has become differentiated after its formation by a Robertsonian translocation and inversions, and has accumulated repetitive DNA sequences. Interestingly, the ex autosomes incorporated into the neo-sex chromosomes retain some autosomal post-translational histone modifications, at least in metaphase I, suggesting that the establishment of functional modifications in neo-sex chromosomes is slower than their sequence differentiation.

  14. Whole chromosome gain does not in itself confer cancer-like chromosomal instability.

    Science.gov (United States)

    Valind, Anders; Jin, Yuesheng; Baldetorp, Bo; Gisselsson, David

    2013-12-24

    Constitutional aneuploidy is typically caused by a single-event meiotic or early mitotic error. In contrast, somatic aneuploidy, found mainly in neoplastic tissue, is attributed to continuous chromosomal instability. More debated as a cause of aneuploidy is aneuploidy itself; that is, whether aneuploidy per se causes chromosomal instability, for example, in patients with inborn aneuploidy. We have addressed this issue by quantifying the level of somatic mosaicism, a proxy marker of chromosomal instability, in patients with constitutional aneuploidy by precise background-filtered dual-color FISH. In contrast to previous studies that used less precise methods, we find that constitutional trisomy, even for large chromosomes that are often trisomic in cancer, does not confer a significantly elevated rate of somatic chromosomal mosaicism in individual cases. Constitutional triploidy was associated with an increased level of somatic mosaicism, but this consisted mostly of reversion from trisomy to disomy and did not correspond to a proportionally elevated level of chromosome mis-segregation in triploids, indicating that the observed mosaicism resulted from a specific accumulation of cells with a hypotriploid chromosome number. In no case did the rate of somatic mosaicism in constitutional aneuploidy exceed that of "chromosomally stable" cancer cells. Our findings show that even though constitutional aneuploidy was in some cases associated with low-level somatic mosaicism, it was insufficient to generate the cancer-like levels expected if aneuploidy single-handedly triggered cancer-like chromosomal instability.

  15. Rapid cloning and bioinformatic analysis of spinach Y chromosome ...

    Indian Academy of Sciences (India)

    The genome of spinach single chromosome complement is about 1000 Mbp, which is the model material to study the molecular mechanisms of plant sex differentiation. The cytological study showed that the biggest spinach chromosome (chromosome 1) was taken as spinach sex chromosome. It had three alleles of ...

  16. Centromeric banding pattern of mitotic chromosomes in Vigna vexillata

    African Journals Online (AJOL)

    Vigna vexillata chromosome characterization was carried out using the Leishman C- banding technique. The results showed that the chromosomes mostly exhibited bands at both the centromeric and telomeric regions. These bands will serve, as a valuable marker for the identification of the chromosomes. Chromosomes 2 ...

  17. Chromosomes in the genesis and progression of ependymomas

    DEFF Research Database (Denmark)

    Rogatto, S R; Casartelli, C; Rainho, C A

    1993-01-01

    chromosomes in three cases. Structural rearrangements of chromosome 2 were a finding for all cases and involved loss of material at 2q32-34. Other structural chromosome abnormalities detected involved chromosomes 4, 6, 10, 11, 12, and X. We also reviewed data on 22 cases previously reported....

  18. Nuclear power and nuclear weapons

    International Nuclear Information System (INIS)

    Vaughen, V.C.A.

    1983-01-01

    The proliferation of nuclear weapons and the expanded use of nuclear energy for the production of electricity and other peaceful uses are compared. The difference in technologies associated with nuclear weapons and nuclear power plants are described

  19. The tilapias' chromosomes influencing sex determination.

    Science.gov (United States)

    Cnaani, A

    2013-01-01

    The sex chromosomes of tilapias (family Cichlidae; genera Oreochromis, Sarotherodon and Tilapia) have been studied for over 50 years, which has gained interest from both agricultural and basic scientific perspectives. Several closely related tilapia species which can interbreed have been studied, and it has been repeatedly demonstrated that there is variation within and between species in the chromosomal sex-determination mechanism. Both male and female heterogametic sex-determination systems have been characterized, as well as epistatic and environmental influences on sex determination. Three different linkage groups (LG1, LG3 and LG23) have been identified as sex-associated chromosomes and have been subjected to further cytogenetic research and analyses of the genes located around the sex-determining region. Variation in the genetic and physical characteristics of the sex chromosomes makes tilapias an excellent model system for studying the evolution of vertebrate sex chromosomes. This review summarizes the progress made along 5 decades of research and the current knowledge of the tilapias' sex chromosomes.

  20. Small Supernumerary Marker Chromosomes in Human Infertility.

    Science.gov (United States)

    Armanet, Narjes; Tosca, Lucie; Brisset, Sophie; Liehr, Thomas; Tachdjian, Gérard

    2015-01-01

    Small supernumerary marker chromosomes (sSMC) are structurally abnormal chromosomes that cannot be unambiguously identified by banding cytogenetics. The objective of this study was to provide an overview of sSMC frequency and characterization in a context of infertility and to review the literature describing sSMC in relation with male and female infertility. Therefore, a systematic literature review on sSMC associated with infertility was conducted by means of a PubMed literature and a sSMC database (http://ssmc-tl.com/sSMC.html) search. A total of 234 patients with infertility were identified as carriers of sSMC. All chromosomes, except chromosomes 10, 19 and the X, were involved in sSMC, and in 72% the sSMC originated from acrocentric chromosomes. Euchromatic imbalances were caused by the presence of sSMC in 30% of the cases. Putative genes have been identified in only 1.2% of sSMC associated with infertility. The implication of sSMC in infertility could be due to a partial trisomy of some genes but also to mechanical effects perturbing meiosis. Further precise molecular and interphase-architecture studies on sSMC are needed in the future to characterize the relationship between this chromosomal anomaly and human infertility. © 2015 S. Karger AG, Basel.

  1. Chromosome Painting by GISH and Multicolor FISH.

    Science.gov (United States)

    Xu, Steven S; Liu, Zhao; Zhang, Qijun; Niu, Zhixia; Jan, Chao-Chien; Cai, Xiwen

    2016-01-01

    Fluorescent in situ hybridization (FISH) is a powerful cytogenetic technique for identifying chromosomes and mapping specific genes and DNA sequences on individual chromosomes. Genomic in situ hybridization (GISH) and multicolor FISH (mc-FISH) represent two special types of FISH techniques. Both GISH and mc-FISH experiments have general steps and features of FISH, including chromosome preparation, probe labeling, blocking DNA preparation, target-probe DNA hybridization, post-hybridization washes, and hybridization signal detection. Specifically, GISH uses total genomic DNA from two species as probe and blocking DNA, respectively, and it can differentiate chromosomes from different genomes. The mc-FISH takes advantage of simultaneous hybridization of several DNA probes labeled by different fluorochromes to different targets on the same chromosome sample. Hybridization signals from different probes are detected using different fluorescence filter sets. Multicolor FISH can provide more structural details for target chromosomes than single-color FISH. In this chapter, we present the general experimental procedures for these two techniques with specific details in the critical steps we have modified in our laboratories.

  2. Flow cytogenetics: progress toward chromosomal aberration detection

    International Nuclear Information System (INIS)

    Carrano, A.V.; Gray, J.W.; Van Dilla, M.A.

    1977-01-01

    Using clonal derivatives of the Chinese hamster M3-1 cell line, we demonstrate the potential of flow systems to karyotype homogeneous aberrations (aberrations which are identical and present in every cell) and to detect heterogeneous aberrations (aberrations which occur randomly in a population and are not identical in every cell). Flow cytometry (FCM) of ethidium bromide stained isolated chromosomes from clone 650A of the M3-1 cells distinguishes nine chromosome types from the fourteen present in the actual karyotype. X-irradiation of this parent 650A clone produced two sub-clones with an altered flow karyotype, that is, their FCM distributions were characterized by the addition of new peaks and alterations in area under existing peaks. From the relative DNA content and area for each peak, as determined by computer analysis, we predicted that each clone had undergone a reciprocal translocation involving chromosomes from two peaks. This prediction was confirmed by Giemsa-banding the metaphase cells. Heterogeneous aberrations are reflected in the flow karyotype as an increase in background, that is, an increase in area underlying the chromosome peaks. This increase is dose dependent but, as yet, the sample variability has been too large for quantitative analysis. Flow sorting of the valleys between chromosome peaks produces enriched fractions of aberrant chromosomes for visual analysis. These approaches are potentially applicable to the analysis of chromsomal aberrations induced by environmental contaminants

  3. Evolutionary stability of sex chromosomes in snakes.

    Science.gov (United States)

    Rovatsos, Michail; Vukić, Jasna; Lymberakis, Petros; Kratochvíl, Lukáš

    2015-12-22

    Amniote vertebrates possess various mechanisms of sex determination, but their variability is not equally distributed. The large evolutionary stability of sex chromosomes in viviparous mammals and birds was believed to be connected with their endothermy. However, some ectotherm lineages seem to be comparably conserved in sex determination, but previously there was a lack of molecular evidence to confirm this. Here, we document a stability of sex chromosomes in advanced snakes based on the testing of Z-specificity of genes using quantitative PCR (qPCR) across 37 snake species (our qPCR technique is suitable for molecular sexing in potentially all advanced snakes). We discovered that at least part of sex chromosomes is homologous across all families of caenophidian snakes (Acrochordidae, Xenodermatidae, Pareatidae, Viperidae, Homalopsidae, Colubridae, Elapidae and Lamprophiidae). The emergence of differentiated sex chromosomes can be dated back to about 60 Ma and preceded the extensive diversification of advanced snakes, the group with more than 3000 species. The Z-specific genes of caenophidian snakes are (pseudo)autosomal in the members of the snake families Pythonidae, Xenopeltidae, Boidae, Erycidae and Sanziniidae, as well as in outgroups with differentiated sex chromosomes such as monitor lizards, iguanas and chameleons. Along with iguanas, advanced snakes are therefore another example of ectothermic amniotes with a long-term stability of sex chromosomes comparable with endotherms. © 2015 The Author(s).

  4. Recurrent chromosome 6 abnormalities in malignant mesothelioma.

    Science.gov (United States)

    Ribotta, M; Roseo, F; Salvio, M; Castagneto, B; Carbone, M; Procopio, A; Giordano, A; Mutti, L

    1998-04-01

    The long latency period between asbestos exposure and the onset of malignant mesothelioma (MM) suggests that a multistep tumorigenesis process occurs whilst the capability of asbestos fibres to interfere directly with chromosomes focuses on the critical role of the chromosomal abnormalities in this neoplasm. The aim of our study was to identify any recurrent chromosomal changes in ten primary MM cell cultures derived from pleural effusions of patients with MM from the same geographic area and environmental and/or occupational exposure to asbestos fibers. Cytogenetic analysis was performed in accordance with International System for Human Cytogenetic Nomenclature. Our results confirmed a great number of cytogenetic abnormalities in MM cells. Recurrent loss of the long arms of chromosome 6 (6q-) was the most frequent abnormality detected (four epithelial and two mixed subtypes) while, on the whole, abnormalities of chromosome 6 were found in nine out of ten cases whereas chromosome 6 was normal only in the case with fibromatous subtype. Monosomy 13 and 17 was found in five cases, monosomy 14 in four cases and 22 in three cases. Since deletion of 6q- was detected even in relatively undisturbed karyotype, we hypothesize a multistep carcinogenic process in which deletion of 6q- is an early event in the development and progression of malignant mesothelioma.

  5. Genome size and chromosome number of Micromeria acropolitana (Lamiaceae), a steno-endemic of Greece

    DEFF Research Database (Denmark)

    Siljak-Yakovlev, Sonia; Tan, Kit; Tsounis, Gregory

    2011-01-01

    The chromosome number 2n = 30, and nuclear DNA amount 2C = 0.79 pg, are determined for the first time for Micromeria acropolitana, a rare and endangered species from the Acropolis in Athens, Greece. The plant was considered extinct but rediscovered in 2006, a hundred years later. Its current status...

  6. Characterizing the chromosomes of the platypus (Ornithorhynchus anatinus).

    Science.gov (United States)

    McMillan, Daniel; Miethke, Pat; Alsop, Amber E; Rens, Willem; O'Brien, Patricia; Trifonov, Vladimir; Veyrunes, Frederic; Schatzkamer, Kyriena; Kremitzki, Colin L; Graves, Tina; Warren, Wesley; Grützner, Frank; Ferguson-Smith, Malcolm A; Graves, Jennifer A Marshall

    2007-01-01

    Like the unique platypus itself, the platypus genome is extraordinary because of its complex sex chromosome system, and is controversial because of difficulties in identification of small autosomes and sex chromosomes. A 6-fold shotgun sequence of the platypus genome is now available and is being assembled with the help of physical mapping. It is therefore essential to characterize the chromosomes and resolve the ambiguities and inconsistencies in identifying autosomes and sex chromosomes. We have used chromosome paints and DAPI banding to identify and classify pairs of autosomes and sex chromosomes. We have established an agreed nomenclature and identified anchor BAC clones for each chromosome that will ensure unambiguous gene localizations.

  7. Polytene chromosome map and inversion polymorphism in Drosophila mediopunctata

    Directory of Open Access Journals (Sweden)

    Galina Ananina

    2002-07-01

    Full Text Available Drosophila mediopunctata belongs to the tripunctata group, and is one of the commonest Drosophila species collected in some places in Brazil, especially in the winter. A standard map of the polytene chromosomes is presented. The breakpoints of the naturally occurring chromosomal rearrangements are marked on the map. The distribution of breaking points through the chromosomes of D. mediopunctata is apparently non-random. Chromosomes X, II and IV show inversion polymorphisms. Chromosome II is the most polymorphic, with 17 inversions, 8 inversions in the distal region and 9 in the proximal region. Chromosome X has four different gene arrangements, while chromosome IV has only two.

  8. The paternal sex ratio chromosome in the parasitic wasp Trichogramma kaykai condenses the paternal chromosomes into a dense chromatin mass

    NARCIS (Netherlands)

    Vugt, van J.J.F.A.; Salverda, M.; Jong, de J.H.S.G.M.; Stouthamer, R.

    2003-01-01

    A recently discovered B chromosome in the parasitoid wasp Trichogramma kaykai was found to be transmitted through males only. Shortly after fertilization, this chromosome eliminates the paternal chromosome set leaving the maternal chromosomes and itself intact. Consequently, the sex ratio in these

  9. Doses in radiation accidents investigated by chromosome aberration analysis

    International Nuclear Information System (INIS)

    Lloyd, D.C.; Purrott, R.J.; Prosser, J.S.; Lelliott, D.J.; Stimpson, L.D.

    1981-03-01

    The results are reviewed from investigations during 1980 into 68 cases of suspected overexposure to radiation. Of these, 37 were associated with industrial radiography, 11 with one or other of the major nuclear organisations and 20 with an institution of research, education or health. 55 of the dose estimates were in the range 0.0 - 0.09 Gy (0 - 9 rad) 5 in the range 0.1 - 0.29 Gy (10 - 29 rad) and for various reasons in 8 cases no biological assessment of dose was possible. The dose estimate for the case with the highest confirmed overexposure was 0.22 Gy (22 rads). The chromosome data are compared with information obtained from physical dosimetry and a brief summary is given of the circumstances of each case. (author)

  10. Automation of the dicentric chromosome assay and related assays

    International Nuclear Information System (INIS)

    Balajee, Adayabalam S.; Dainiak, Nicholas

    2016-01-01

    Dicentric Chromosome Assay (DCA) is considered to be the 'gold standard' for personalized dose assessment in humans after accidental or incidental radiation exposure. Although this technique is superior to other cytogenetic assays in terms of specificity and sensitivity, its potential application to radiation mass casualty scenarios is highly restricted because DCA is time consuming and labor intensive when performed manually. Therefore, it is imperative to develop high throughput automation techniques to make DCA suitable for radiological triage scenarios. At the Cytogenetic Biodosimetry Laboratory in Oak Ridge, efforts are underway to develop high throughput automation of DCA. Current status on development of various automated cytogenetic techniques in meeting the biodosimetry needs of radiological/nuclear incident(s) will be discussed

  11. Nuclear rights - nuclear wrongs

    Energy Technology Data Exchange (ETDEWEB)

    Paul, E.F.; Miller, F.D.; Paul, J.; Ahrens, J.

    1986-01-01

    This book contains 11 selections. The titles are: Three Ways to Kill Innocent Bystanders: Some Conundrums Concerning the Morality of War; The International Defense of Liberty; Two Concepts of Deterrence; Nuclear Deterrence and Arms Control; Ethical Issues for the 1980s; The Moral Status of Nuclear Deterrent Threats; Optimal Deterrence; Morality and Paradoxical Deterrence; Immoral Risks: A Deontological Critique of Nuclear Deterrence; No War Without Dictatorship, No Peace Without Democracy: Foreign Policy as Domestic Politics; Marxism-Leninism and its Strategic Implications for the United States; Tocqueveille War.

  12. Nuclear moments

    CERN Document Server

    Kopferman, H; Massey, H S W

    1958-01-01

    Nuclear Moments focuses on the processes, methodologies, reactions, and transformations of molecules and atoms, including magnetic resonance and nuclear moments. The book first offers information on nuclear moments in free atoms and molecules, including theoretical foundations of hyperfine structure, isotope shift, spectra of diatomic molecules, and vector model of molecules. The manuscript then takes a look at nuclear moments in liquids and crystals. Discussions focus on nuclear paramagnetic and magnetic resonance and nuclear quadrupole resonance. The text discusses nuclear moments and nucl

  13. Klinefelter syndrome and other sex chromosomal aneuploidies

    Directory of Open Access Journals (Sweden)

    Graham John M

    2006-10-01

    Full Text Available Abstract The term Klinefelter syndrome (KS describes a group of chromosomal disorder in which there is at least one extra X chromosome to a normal male karyotype, 46,XY. XXY aneuploidy is the most common disorder of sex chromosomes in humans, with prevalence of one in 500 males. Other sex chromosomal aneuploidies have also been described, although they are much less frequent, with 48,XXYY and 48,XXXY being present in 1 per 17,000 to 1 per 50,000 male births. The incidence of 49,XXXXY is 1 per 85,000 to 100,000 male births. In addition, 46,XX males also exist and it is caused by translocation of Y material including sex determining region (SRY to the X chromosome during paternal meiosis. Formal cytogenetic analysis is necessary to make a definite diagnosis, and more obvious differences in physical features tend to be associated with increasing numbers of sex chromosomes. If the diagnosis is not made prenatally, 47,XXY males may present with a variety of subtle clinical signs that are age-related. In infancy, males with 47,XXY may have chromosomal evaluations done for hypospadias, small phallus or cryptorchidism, developmental delay. The school-aged child may present with language delay, learning disabilities, or behavioral problems. The older child or adolescent may be discovered during an endocrine evaluation for delayed or incomplete pubertal development with eunuchoid body habitus, gynecomastia, and small testes. Adults are often evaluated for infertility or breast malignancy. Androgen replacement therapy should begin at puberty, around age 12 years, in increasing dosage sufficient to maintain age appropriate serum concentrations of testosterone, estradiol, follicle stimulating hormone (FSH, and luteinizing hormone (LH. The effects on physical and cognitive development increase with the number of extra Xs, and each extra X is associated with an intelligence quotient (IQ decrease of approximately 15–16 points, with language most affected

  14. 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.

  15. Marked chromosomes associations in catarrhine monkeys, with a note on chromosome associations in other primate groups

    NARCIS (Netherlands)

    Boer, L.E.M. de

    In metaphase figures, obtained from cultures of whole blood, associations of the marked chromosomes were found in species of the following genera: Macaca, Cercocebus, Cercopithecus and Symphalangus. The different types of these associations are discussed. A note is given on chromosome associations

  16. 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)

  17. Tracking of chromosome dynamics in live Streptococcus pneumoniae reveals that transcription promotes chromosome segregation

    NARCIS (Netherlands)

    Kjos, Morten; Veening, Jan-Willem

    Chromosome segregation is an essential part of the bacterial cell cycle but is poorly characterized in oval-shaped streptococci. Using time-lapse fluorescence microscopy and total internal reflection fluorescence microscopy, we have tracked the dynamics of chromosome segregation in live cells of the

  18. Chromosome and genome size variation in Luzula (Juncaceae), a genus with holocentric chromosomes

    Czech Academy of Sciences Publication Activity Database

    Bozek, M.; Leitch, A. R.; Leitch, I. J.; Záveská Drábková, Lenka; Kuta, E.

    2012-01-01

    Roč. 170, č. 4 (2012), s. 529-541 ISSN 0024-4074 R&D Projects: GA ČR GP206/07/P147 Institutional support: RVO:67985939 Keywords : chromosomal evolution * endopolyploidy * holokinetic chromosome * karyotype evolution * tetraploides * centromeres * TRNF intergenic spacer Subject RIV: EF - Botanics Impact factor: 2.589, year: 2012

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

    Science.gov (United States)

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

    2007-05-02

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

  20. 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

  1. MATERNAL SERUM CA 125 LEVELS IN PREGNANCIES WITH CHROMOSOMALLY-NORMAL AND CHROMOSOMALLY-ABNORMAL FETUSES

    NARCIS (Netherlands)

    VANLITH, JMM; MANTINGH, A; DEBRUIJN, HWA; KLOOSTERMAN, MD; KANHAI, HHH; WOLF, H; EVERHARDT, E; CHRISTIAENS, GCML

    1993-01-01

    We measured the maternal serum cancer antigen 125 (MS-CA 125) levels in 98 nonpregnant women, 765 first- and second-trimester pregnancies with chromosomally-normal fetuses, and 54 chromosomally-abnormal pregnancies. To determine the MS-CA 125 concentration, we used a new automated microparticle

  2. 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

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

    Directory of Open Access Journals (Sweden)

    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

  4. Evolutionary and dispersal history of Triatoma infestans, main vector of Chagas disease, by chromosomal markers.

    Science.gov (United States)

    Panzera, Francisco; Ferreiro, María J; Pita, Sebastián; Calleros, Lucía; Pérez, Ruben; Basmadjián, Yester; Guevara, Yenny; Brenière, Simone Frédérique; Panzera, Yanina

    2014-10-01

    Chagas disease, one of the most important vector-borne diseases in the Americas, is caused by Trypanosoma cruzi and transmitted to humans by insects of the subfamily Triatominae. An effective control of this disease depends on elimination of vectors through spraying with insecticides. Genetic research can help insect control programs by identifying and characterizing vector populations. In southern Latin America, Triatoma infestans is the main vector and presents two distinct lineages, known as Andean and non-Andean chromosomal groups, that are highly differentiated by the amount of heterochromatin and genome size. Analyses with nuclear and mitochondrial sequences are not conclusive about resolving the origin and spread of T. infestans. The present paper includes the analyses of karyotypes, heterochromatin distribution and chromosomal mapping of the major ribosomal cluster (45S rDNA) to specimens throughout the distribution range of this species, including pyrethroid-resistant populations. A total of 417 specimens from seven different countries were analyzed. We show an unusual wide rDNA variability related to number and chromosomal position of the ribosomal genes, never before reported in species with holocentric chromosomes. Considering the chromosomal groups previously described, the ribosomal patterns are associated with a particular geographic distribution. Our results reveal that the differentiation process between both T. infestans chromosomal groups has involved significant genomic reorganization of essential coding sequences, besides the changes in heterochromatin and genomic size previously reported. The chromosomal markers also allowed us to detect the existence of a hybrid zone occupied by individuals derived from crosses between both chromosomal groups. Our genetic studies support the hypothesis of an Andean origin for T. infestans, and suggest that pyrethroid-resistant populations from the Argentinean-Bolivian border are most likely the result of

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

    Science.gov (United States)

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

    2015-10-01

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

  6. Sex Chromosome Evolution in Amniotes: Applications for Bacterial Artificial Chromosome Libraries

    Directory of Open Access Journals (Sweden)

    Daniel E. Janes

    2011-01-01

    Full Text Available Variability among sex chromosome pairs in amniotes denotes a dynamic history. Since amniotes diverged from a common ancestor, their sex chromosome pairs and, more broadly, sex-determining mechanisms have changed reversibly and frequently. These changes have been studied and characterized through the use of many tools and experimental approaches but perhaps most effectively through applications for bacterial artificial chromosome (BAC libraries. Individual BAC clones carry 100–200 kb of sequence from one individual of a target species that can be isolated by screening, mapped onto karyotypes, and sequenced. With these techniques, researchers have identified differences and similarities in sex chromosome content and organization across amniotes and have addressed hypotheses regarding the frequency and direction of past changes. Here, we review studies of sex chromosome evolution in amniotes and the ways in which the field of research has been affected by the advent of BAC libraries.

  7. 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....

  8. 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)

  9. Chromosome 10q tetrasomy: First reported case

    Energy Technology Data Exchange (ETDEWEB)

    Blackston, R.D.; May, K.M.; Jones, F.D. [Emory Univ., Atlanta, GA (United States)] [and others

    1994-09-01

    While there are several reports of trisomy 10q (at least 35), we are not aware of previous cases of 10q tetrasomy. We present what we believe to be the initial report of such a case. R.J. is a 6 1/2 year old white male who presented with multiple dysmorphic features, marked articulation problems, hyperactivity, and developmental delays. He is the product of a term uncomplicated pregnancy. There was a normal spontaneous vaginal delivery with a birth weight of 6 lbs. 4oz. and length was 19 1/2 inch. Dysmorphic features include small size, an asymmetrically small head, low set ears with overfolded helixes, bilateral ptosis, downslanting eyes, right eye esotropia, prominent nose, asymmetric facies, high palate, mild pectus excavatum deformity of chest, and hyperextensible elbow joints. The patient is in special needs classes for mildly mentally handicapped students. Chromosome analysis at a resolution of 800 bands revealed a complex rearrangement of chromosomes 10 and 11. The segment 10q25.3 to q16.3 appears to be inverted and duplicated within the long arm of chromosome 10 at band q25.3 and the same segment of chromosome 10 is present on the terminal end of the short arm of chromosome 11. There is no visible loss of material from chromosome 11. Fluorescence in situ hybridization was performed with a chromosome 10 specific {open_quotes}paint{close_quotes} to confirm that all of the material on the abnormal 10 and the material on the terminal short arm of 11 was from chromosome 10. Thus, it appears that the segment 10q25.3 to q26.3 is present in four copies. Parental chromosome studies are normal. We compared findings which differ in that the case of 10q tetrasomy did not have prenatal growth deficiency, microphthalmia, cleft palate, digital anomalies, heart, or renal defects. Whereas most cases of 10q trisomy are said to have severe mental deficiency, our case of 10q tetrasomy was only mildly delayed. We report this first apparent cited case of 10q tetrasomy.

  10. Three-dimensional positioning of B chromosomes in fibroblast nuclei of the red fox and the chinese raccoon dog.

    Science.gov (United States)

    Kociucka, B; Sosnowski, J; Kubiak, A; Nowak, A; Pawlak, P; Szczerbal, I

    2013-01-01

    Great progress has been achieved over the last years in studies on chromosome arrangement in mammalian cell nuclei. Growing evidence indicates that the genome's spatial organization is of functional relevance. So far, no attention has been paid to the nuclear organization of B chromosomes (Bs). In this study we have examined nuclear positioning of Bs in 2 species from the Canidae family--the red fox and the Chinese raccoon dog. Using 2D and 3D fluorescence in situ hybridization and 2 gene-specific probes (C-KIT and PDGFRA), we analyzed the location of Bs in fibroblast nuclei. We found that small Bs of the red fox occupied mostly the interior of the nucleus, while medium-sized Bs of the Chinese raccoon dog were observed in the peripheral area of the nucleus as well as in intermediate and interior locations. The more uniform distribution of B chromosomes in the Chinese raccoon dog may be the result of differences in their size, since 3 morphological types of Bs are distinguished in this species. Our results indicate that 3D positioning of B chromosomes in fibroblast nuclei of the 2 canid species is in agreement with the chromosome size-dependent theory. Copyright © 2013 S. Karger AG, Basel.

  11. Chromosome-specific DNA Repeat Probes

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-03-16

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

  12. Y chromosome STR typing in crime casework.

    Science.gov (United States)

    Roewer, Lutz

    2009-01-01

    Since the beginning of the nineties the field of forensic Y chromosome analysis has been successfully developed to become commonplace in laboratories working in crime casework all over the world. The ability to identify male-specific DNA renders highly variable Y-chromosomal polymorphisms, the STR sequences, an invaluable addition to the standard panel of autosomal loci used in forensic genetics. The male-specificity makes the Y chromosome especially useful in cases of male/female cell admixture, namely in sexual assault cases. On the other hand, the haploidy and patrilineal inheritance complicates the interpretation of a Y-STR match, because male relatives share for several generations an identical Y-STR profile. Since paternal relatives tend to live in the geographic and cultural territory of their ancestors, the Y chromosome analysis has a potential to make inferences on the population of origin of a given DNA profile. This review addresses the fields of application of Y chromosome haplotyping, the interpretation of results, databasing efforts and population genetics aspects.

  13. Chromosomal polymorphism in the Sporothrix schenckii complex.

    Science.gov (United States)

    Sasaki, Alexandre A; Fernandes, Geisa F; Rodrigues, Anderson M; Lima, Fábio M; Marini, Marjorie M; Dos S Feitosa, Luciano; de Melo Teixeira, Marcus; Felipe, Maria Sueli Soares; da Silveira, José Franco; de Camargo, Zoilo P

    2014-01-01

    Sporotrichosis is a polymorphic disease caused by a complex of thermodimorphic fungi including S. brasiliensis, S. schenckii sensu stricto (s. str.), S. globosa and S. luriei. Humans and animals can acquire the disease through traumatic inoculation of propagules into the subcutaneous tissue. Despite the importance of sporotrichosis as a disease that can take epidemic proportions there are just a few studies dealing with genetic polymorphisms and genomic architecture of these pathogens. The main objective of this study was to investigate chromosomal polymorphisms and genomic organization among different isolates in the S. schenckii complex. We used pulsed field gel electrophoresis (PFGE) to separate chromosomal fragments of isolated DNA, followed by probe hybridization. Nine loci (β-tubulin, calmodulin, catalase, chitin synthase 1, Internal Transcribed Spacer, Pho85 cyclin-dependent kinase, protein kinase C Ss-2, G protein α subunit and topoisomerase II) were mapped onto chromosomal bands of Brazilian isolates of S. schenckii s. str. and S. brasiliensis. Our results revealed the presence of intra and interspecies polymorphisms in chromosome number and size. The gene hybridization analysis showed that closely related species in phylogenetic analysis had similar genetic organizations, mostly due to identification of synteny groups in chromosomal bands of similar sizes. Our results bring new insights into the genetic diversity and genome organization among pathogenic species in the Sporothrix schenckii complex.

  14. 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.

  15. U1 snDNA clusters in grasshoppers: chromosomal dynamics and genomic organization.

    Science.gov (United States)

    Anjos, A; Ruiz-Ruano, F J; Camacho, J P M; Loreto, V; Cabrero, J; de Souza, M J; Cabral-de-Mello, D C

    2015-02-01

    The spliceosome, constituted by a protein set associated with small nuclear RNA (snRNA), is responsible for mRNA maturation through intron removal. Among snRNA genes, U1 is generally a conserved repetitive sequence. To unveil the chromosomal/genomic dynamics of this multigene family in grasshoppers, we mapped U1 genes by fluorescence in situ hybridization in 70 species belonging to the families Proscopiidae, Pyrgomorphidae, Ommexechidae, Romaleidae and Acrididae. Evident clusters were observed in all species, indicating that, at least, some U1 repeats are tandemly arrayed. High conservation was observed in the first four families, with most species carrying a single U1 cluster, frequently located in the third or fourth longest autosome. By contrast, extensive variation was observed among Acrididae, from a single chromosome pair carrying U1 to all chromosome pairs carrying it, with occasional occurrence of two or more clusters in the same chromosome. DNA sequence analysis in Eyprepocnemis plorans (species carrying U1 clusters on seven different chromosome pairs) and Locusta migratoria (carrying U1 in a single chromosome pair) supported the coexistence of functional and pseudogenic lineages. One of these pseudogenic lineages was truncated in the same nucleotide position in both species, suggesting that it was present in a common ancestor to both species. At least in E. plorans, this U1 snDNA pseudogenic lineage was associated with 5S rDNA and short interspersed elements (SINE)-like mobile elements. Given that we conclude in grasshoppers that the U1 snDNA had evolved under the birth-and-death model and that its intragenomic spread might be related with mobile elements.

  16. Chromosome Numbers and Genome Size Variation in Indian Species of Curcuma (Zingiberaceae)

    Science.gov (United States)

    Leong-Škorničková, Jana; Šída, Otakar; Jarolímová, Vlasta; Sabu, Mamyil; Fér, Tomáš; Trávníček, Pavel; Suda, Jan

    2007-01-01

    Background and Aims Genome size and chromosome numbers are important cytological characters that significantly influence various organismal traits. However, geographical representation of these data is seriously unbalanced, with tropical and subtropical regions being largely neglected. In the present study, an investigation was made of chromosomal and genome size variation in the majority of Curcuma species from the Indian subcontinent, and an assessment was made of the value of these data for taxonomic purposes. Methods Genome size of 161 homogeneously cultivated plant samples classified into 51 taxonomic entities was determined by propidium iodide flow cytometry. Chromosome numbers were counted in actively growing root tips using conventional rapid squash techniques. Key Results Six different chromosome counts (2n = 22, 42, 63, >70, 77 and 105) were found, the last two representing new generic records. The 2C-values varied from 1·66 pg in C. vamana to 4·76 pg in C. oligantha, representing a 2·87-fold range. Three groups of taxa with significantly different homoploid genome sizes (Cx-values) and distinct geographical distribution were identified. Five species exhibited intraspecific variation in nuclear DNA content, reaching up to 15·1 % in cultivated C. longa. Chromosome counts and genome sizes of three Curcuma-like species (Hitchenia caulina, Kaempferia scaposa and Paracautleya bhatii) corresponded well with typical hexaploid (2n = 6x = 42) Curcuma spp. Conclusions The basic chromosome number in the majority of Indian taxa (belonging to subgenus Curcuma) is x = 7; published counts correspond to 6x, 9x, 11x, 12x and 15x ploidy levels. Only a few species-specific C-values were found, but karyological and/or flow cytometric data may support taxonomic decisions in some species alliances with morphological similarities. Close evolutionary relationships among some cytotypes are suggested based on the similarity in homoploid genome sizes and geographical grouping

  17. U1 snDNA clusters in grasshoppers: chromosomal dynamics and genomic organization

    Science.gov (United States)

    Anjos, A; Ruiz-Ruano, F J; Camacho, J P M; Loreto, V; Cabrero, J; de Souza, M J; Cabral-de-Mello, D C

    2015-01-01

    The spliceosome, constituted by a protein set associated with small nuclear RNA (snRNA), is responsible for mRNA maturation through intron removal. Among snRNA genes, U1 is generally a conserved repetitive sequence. To unveil the chromosomal/genomic dynamics of this multigene family in grasshoppers, we mapped U1 genes by fluorescence in situ hybridization in 70 species belonging to the families Proscopiidae, Pyrgomorphidae, Ommexechidae, Romaleidae and Acrididae. Evident clusters were observed in all species, indicating that, at least, some U1 repeats are tandemly arrayed. High conservation was observed in the first four families, with most species carrying a single U1 cluster, frequently located in the third or fourth longest autosome. By contrast, extensive variation was observed among Acrididae, from a single chromosome pair carrying U1 to all chromosome pairs carrying it, with occasional occurrence of two or more clusters in the same chromosome. DNA sequence analysis in Eyprepocnemis plorans (species carrying U1 clusters on seven different chromosome pairs) and Locusta migratoria (carrying U1 in a single chromosome pair) supported the coexistence of functional and pseudogenic lineages. One of these pseudogenic lineages was truncated in the same nucleotide position in both species, suggesting that it was present in a common ancestor to both species. At least in E. plorans, this U1 snDNA pseudogenic lineage was associated with 5S rDNA and short interspersed elements (SINE)-like mobile elements. Given that we conclude in grasshoppers that the U1 snDNA had evolved under the birth-and-death model and that its intragenomic spread might be related with mobile elements. PMID:25248465

  18. Brown and polar bear Y chromosomes reveal extensive male-biased gene flow within brother lineages.

    Science.gov (United States)

    Bidon, Tobias; Janke, Axel; Fain, Steven R; Eiken, Hans Geir; Hagen, Snorre B; Saarma, Urmas; Hallström, Björn M; Lecomte, Nicolas; Hailer, Frank

    2014-06-01

    Brown and polar bears have become prominent examples in phylogeography, but previous phylogeographic studies relied largely on maternally inherited mitochondrial DNA (mtDNA) or were geographically restricted. The male-specific Y chromosome, a natural counterpart to mtDNA, has remained underexplored. Although this paternally inherited chromosome is indispensable for comprehensive analyses of phylogeographic patterns, technical difficulties and low variability have hampered its application in most mammals. We developed 13 novel Y-chromosomal sequence and microsatellite markers from the polar bear genome and screened these in a broad geographic sample of 130 brown and polar bears. We also analyzed a 390-kb-long Y-chromosomal scaffold using sequencing data from published male ursine genomes. Y chromosome evidence support the emerging understanding that brown and polar bears started to diverge no later than the Middle Pleistocene. Contrary to mtDNA patterns, we found 1) brown and polar bears to be reciprocally monophyletic sister (or rather brother) lineages, without signals of introgression, 2) male-biased gene flow across continents and on phylogeographic time scales, and 3) male dispersal that links the Alaskan ABC islands population to mainland brown bears. Due to female philopatry, mtDNA provides a highly structured estimate of population differentiation, while male-biased gene flow is a homogenizing force for nuclear genetic variation. Our findings highlight the importance of analyzing both maternally and paternally inherited loci for a comprehensive view of phylogeographic history, and that mtDNA-based phylogeographic studies of many mammals should be reevaluated. Recent advances in sequencing technology render the analysis of Y-chromosomal variation feasible, even in nonmodel organisms. © The Author 2014. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e

  19. Analysis of morphological markers of chromosomal instability in ascitic fluid.

    Science.gov (United States)

    Tyagi, Ruchita; Dey, Pranab; Uppal, Radha; Rajwanshi, Arvind

    2015-10-01

    Chromosomal instability (CI) plays a major role in the carcinogenesis. Micronuclei, nuclear budding, chromatin bridges,and multipolar mitoses are the morphological markers of CI and have never been studied in routine cytological specimens. Aims of the study is to analyze the significance of morphological markers of CI in malignant and benign ascitic fluid smears. A total of sixty benign and 40 malignant ascitic fluid samples were selected for this study. All the cases with malignant ascitic fluid showed histopathological evidence of malignancy in ovary and omentum. Chromatin bridges, multipolar mitosis (MPM), micronuclei and nuclear budding were counted in 1000 cells in representative May Grunwald Giemsa (MGG) stained smears. The CI markers were correlated with the cytological diagnosis of effusion. The mean number of micronuclei, nuclear budding, chromatin bridge and multipolar mitoses found in malignant effusions were 13.2611.79, 10.1067.07, 2.5362.67, 1.964.5, respectively. The mean number of micronuclei, nuclear budding, anaphase bridges, and MPM found in benign effusion cases were 0.566761.07934, 0.516761.33, 0.66760.25, and 0, respectively. The student t test showed significant differences between malignant and benign ascitic fluid samples for each marker of CI. This is the first comprehensive study of morphological markers of CI in ascitic fluid smears. This study has shown strong correlation between markers of CI and cytological diagnosis of malignancy. In future, the knowledge of these markers can be applied to diagnose malignancy in suspected cases of effusion in difficult situations. © 2015 Wiley Periodicals, Inc.

  20. A powerful parent-of-origin effects test for qualitative traits on X chromosome in general pedigrees.

    Science.gov (United States)

    Zou, Qi-Lei; You, Xiao-Ping; Li, Jian-Long; Fung, Wing Kam; Zhou, Ji-Yuan

    2018-01-05

    Genomic imprinting is one of the well-known epigenetic factors causing the association between traits and genes, and has generally been examined by detecting parent-of-origin effects of alleles. A lot of methods have been proposed to test for parent-of-origin effects on autosomes based on nuclear families and general pedigrees. Although these parent-of-origin effects tests on autosomes have been available for more than 15 years, there has been no statistical test developed to test for parent-of-origin effects on X chromosome, until the parental-asymmetry test on X chromosome (XPAT) and its extensions were recently proposed. However, these methods on X chromosome are only applicable to nuclear families and thus are not suitable for general pedigrees. In this article, we propose the pedigree parental-asymmetry test on X chromosome (XPPAT) statistic to test for parent-of-origin effects in the presence of association, which can accommodate general pedigrees. When there are missing genotypes in some pedigrees, we further develop the Monte Carlo pedigree parental-asymmetry test on X chromosome (XMCPPAT) to test for parent-of-origin effects, by inferring the missing genotypes given the observed genotypes based on a Monte Carlo estimation. An extensive simulation study has been carried out to investigate the type I error rates and the powers of the proposed tests. Our simulation results show that the proposed methods control the size well under the null hypothesis of no parent-of-origin effects. Moreover, XMCPPAT substantially outperforms the existing tests and has a much higher power than XPPAT which only uses complete nuclear families (with both parents) from pedigrees. We also apply the proposed methods to analyze rheumatoid arthritis data for their practical use. The proposed XPPAT and XMCPPAT test statistics are valid and powerful in detecting parent-of-origin effects on X chromosome for qualitative traits based on general pedigrees and thus are recommended.

  1. Nuclear power

    OpenAIRE

    2005-01-01

    David Waller and Alan McDonald ask whether a nuclear renaissance can be predicted; Judith M. Greenwald discusses keeping the nuclear power option open; Paul Mobbs considers the availability of uranium and the future of nuclear energy.

  2. Nuclear Medicine.

    Science.gov (United States)

    Badawi, Ramsey D.

    2001-01-01

    Describes the use of nuclear medicine techniques in diagnosis and therapy. Describes instrumentation in diagnostic nuclear medicine and predicts future trends in nuclear medicine imaging technology. (Author/MM)

  3. Plasmid and chromosome partitioning: surprises from phylogeny

    DEFF Research Database (Denmark)

    Gerdes, Kenn; Møller-Jensen, Jakob; Bugge Jensen, Rasmus

    2000-01-01

    Plasmids encode partitioning genes (par) that are required for faithful plasmid segregation at cell division. Initially, par loci were identified on plasmids, but more recently they were also found on bacterial chromosomes. We present here a phylogenetic analysis of par loci from plasmids...... and chromosomes from prokaryotic organisms. All known plasmid-encoded par loci specify three components: a cis-acting centromere-like site and two trans-acting proteins that form a nucleoprotein complex at the centromere (i.e. the partition complex). The proteins are encoded by two genes in an operon...... that is autoregulated by the par-encoded proteins. In all cases, the upstream gene encodes an ATPase that is essential for partitioning. Recent cytological analyses indicate that the ATPases function as adaptors between a host-encoded component and the partition complex and thereby tether plasmids and chromosomal...

  4. Chromosomal aberrations induced by alpha particles

    International Nuclear Information System (INIS)

    Guerrero C, C.; Brena V, M.

    2005-01-01

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

  5. The complete sequence of human chromosome 5

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-04-15

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

  6. 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.

  7. Can molecular cell biology explain chromosome motions?

    Directory of Open Access Journals (Sweden)

    Gagliardi L

    2011-05-01

    Full Text Available Abstract Background Mitotic chromosome motions have recently been correlated with electrostatic forces, but a lingering "molecular cell biology" paradigm persists, proposing binding and release proteins or molecular geometries for force generation. Results Pole-facing kinetochore plates manifest positive charges and interact with negatively charged microtubule ends providing the motive force for poleward chromosome motions by classical electrostatics. This conceptual scheme explains dynamic tracking/coupling of kinetochores to microtubules and the simultaneous depolymerization of kinetochore microtubules as poleward force is generated. Conclusion We question here why cells would prefer complex molecular mechanisms to move chromosomes when direct electrostatic interactions between known bound charge distributions can accomplish the same task much more simply.

  8. Non-disjunction of chromosome 18

    DEFF Research Database (Denmark)

    Bugge, M; Collins, A; Petersen, M B

    1998-01-01

    A sample of 100 trisomy 18 conceptuses analysed separately and together with a published sample of 61 conceptuses confirms that an error in maternal meiosis II (MII) is the most frequent cause of non-disjunction for chromosome 18. This is unlike all other human trisomies that have been studied......, which show a higher frequency in maternal meiosis I (MI). Maternal MI trisomy 18 shows a low frequency of recombination in proximal p and medial q, but not the reduction in proximal q observed in chromosome 21 MI non-disjunction. Maternal MII non-disjunction does not fit the entanglement model...... that predicts increased recombination, especially near the centromere. Whereas recent data on MII trisomy 21 show the predicted increase in recombination proximally, maternal MII trisomy 18 has non-significantly reduced recombination. Therefore, chromosome-specific factors must complicate the simple model...

  9. Bias of purine stretches in sequenced chromosomes

    DEFF Research Database (Denmark)

    Ussery, David; Soumpasis, Dikeos Mario; Brunak, Søren

    2002-01-01

    We examined more than 700 DNA sequences (full length chromosomes and plasmids) for stretches of purines (R) or pyrimidines (Y) and alternating YR stretches; such regions will likely adopt structures which are different from the canonical B-form. Since one turn of the DNA helix is roughly 10 bp, we...... to contain 1.0% of purine tracts and also 1.0% of the alternating pyr/pur tracts. In the vast majority of cases, there are more purine tracts than would be expected from a random sequence, with an average of 3.5%, significantly larger than the expectation value. The fraction of the chromosomes containing pyr......, in eukaryotes there is an abundance of long stretches of purines or alternating purine/pyrimidine tracts, which cannot be explained in this way; these sequences are likely to play an important role in eukaryotic chromosome organisation....

  10. The Barley Chromosome 5 Linkage Map

    DEFF Research Database (Denmark)

    Jensen, J.; Jørgensen, Jørgen Helms

    1975-01-01

    The distances between nine loci on barley chromosome 5 have been studied in five two-point tests, three three-point tests, and one four-point test. Our previous chromosome 5 linkage map, which contained eleven loci mapped from literature data (Jensen and Jørgensen 1975), is extended with four loci......: wst5 (white streaks), necl (necrotic leaf spots), Ml-nn (powdery mildew resistance), and Pa4 (leaf rust resistance). Further, the two sections of the map are united, and the precision of the map is improved. A system for designating the positions of the loci on the linkage map is proposed. A 0......-position is fixed on the map by a locus (necl), which has a good marker gene located centrally in the linkage group. The positions of the other loci are their distances in centimorgans from the 0-position; loci in the direction of the short chromosome arm are assigned positive values and those...

  11. Origin of extra chromosome in Patau syndrome.

    Science.gov (United States)

    Ishikiriyama, S; Niikawa, N

    1984-01-01

    Five live-born infants with Patau syndrome were studied for the nondisjunctional origin of the extra chromosome. Transmission modes of chromosomes 13 from parents to a child were determined using both QFQ- and RFA-heteromorphisms as markers, and the origin was ascertained in all of the patients. The extra chromosome had originated in nondisjunction at the maternal first meiotic division in two patients, at the maternal second meiosis in other two, and at the paternal first meiosis in the remaining one. Summarizing the results of the present study, together with those of the previous studies on a liveborn and abortuses with trisomy 13, nondisjunction at the maternal and the paternal meiosis occurred in this trisomy in the ratio of 14:3. This ratio is not statistically different from that inferred from the previous studies for Down syndrome. These findings suggest that there may be a fundamental mechanism common to the occurrence of nondisjunction in the acrocentric trisomies.

  12. Delayed chromosomal instability caused by large deletion

    International Nuclear Information System (INIS)

    Ojima, M.; Suzuki, K.; Kodama, S.; Watanabe, M.

    2003-01-01

    Full text: There is accumulating evidence that genomic instability, manifested by the expression of delayed phenotypes, is induced by X-irradiation but not by ultraviolet (UV) light. It is well known that ionizing radiation, such as X-rays, induces DNA double strand breaks, but UV-light mainly causes base damage like pyrimidine dimers and (6-4) photoproducts. Although the mechanism of radiation-induced genomic instability has not been thoroughly explained, it is suggested that DNA double strand breaks contribute the induction of genomic instability. We examined here whether X-ray induced gene deletion at the hprt locus induces delayed instability in chromosome X. SV40-immortalized normal human fibroblasts, GM638, were irradiated with X-rays (3, 6 Gy), and the hprt mutants were isolated in the presence of 6-thioguanine (6-TG). A 2-fold and a 60-fold increase in mutation frequency were found by 3 Gy and 6 Gy irradiation, respectively. The molecular structure of the hprt mutations was determined by multiplex polymerase chain reaction of nine exons. Approximately 60% of 3 Gy mutants lost a part or the entire hprt gene, and the other mutants showed point mutations like spontaneous mutants. All 6 Gy mutants show total gene deletion. The chromosomes of the hprt mutants were analyzed by Whole Human Chromosome X Paint FISH or Xq telomere FISH. None of the point or partial gene deletion mutants showed aberrations of X-chromosome, however total gene deletion mutants induced translocations and dicentrics involving chromosome X. These results suggest that large deletion caused by DNA double strand breaks destabilizes chromosome structure, which may be involved in an induction of radiation-induced genomic instability

  13. Chromosomal radiosensitivity of prostate cancer patients

    International Nuclear Information System (INIS)

    McRobbie, M.L.; Riches, A.; Baxby, K.

    2003-01-01

    Full text: Radiosensitivity of peripheral blood lymphocytes from prostate cancer patients is being investigated using the G2 assay and the Cytokinesis Block Micronucleus(CBMN)assay. The G2 assay evaluates chromosomal damage caused by irradiating cells in the G2 phase of the cell cycle. The CBMN assay quantifies the post mitotic micronuclei, which are the expression of damage incurred during G0. An association between hypersensitivity to the chromosome damaging effects of ionising radiation and cancer predispostion has been demonstrated in a number of heritable conditions by using the aforementioned techniques. Recently, increased chromosomal radiosensitivity has been demonstrated in a significant proportion of patients with no obvious family history of malignancy. The aim of this study is to establish whether a group of prostatic carcinoma patients exists and if so whether there are any correlations between their G2 and G0 sensitivities. The study has shown there is no correlation between G2 and G0 sensitivity, confirming the general trend that individuals exhibiting chromosomal radiosensitivity are defective in only one mechanism and G2 and G0 sensitivity are largely independent. Current data indicates that there is an identifiable group of men within the prostate cancer population with increased chromosomal radiosensitivity. Using the G2 assay and the 90th percentile of the controls as a cut off point for sensitivity, no significant difference between the controls and the patient population has been found. However, using the CBMN assay and again the 90th percentile, approximately 11% of the control group are sensitive compared with approximately 40% of the carcinoma cases. The implications of this increased radiosensitivity are as yet unclear, but it is indicative of increased chromosomal fragility and therefore, possibly associated with malignant transformation. Hence, it may prove a useful tool in identifying individuals at increased risk of developing

  14. Molecular mapping of chromosomes 17 and X

    Energy Technology Data Exchange (ETDEWEB)

    Barker, D.F.

    1989-01-01

    The basic aims of this project are the construction of high density genetic maps of chromosomes 17 and X and the utilization of these maps for the subsequent isolation of a set of physically overlapping DNA segment clones. The strategy depends on the utilization of chromosome specific libraries of small (1--15 kb) segments from each of the two chromosomes. Since the time of submission of our previous progress report, we have refined the genetic map of markers which we had previously isolated for chromosome 17. We have completed our genetic mapping in CEPH reference and NF1 families of 15 markers in the pericentric region of chromosome 17. Physical mapping results with three probes, were shown be in very close genetic proximity to the NF1 gene, with respect to two translocation breakpoints which disrupt the activity of the gene. All three of the probes were found to lie between the centromere and the most proximal translocation breakpoint, providing important genetic markers proximal to the NF1 gene. Our primary focus has shifted to the X chromosome. We have isolated an additional 30 polymorphic markers, bringing the total number we have isolated to over 80. We have invested substantial effort in characterizing the polymorphisms at each of these loci and constructed plasmid subclones which reveal the polymorphisms for nearly all of the loci. These subclones are of practical value in that they produce simpler and stronger patterns on human genomic Southern blots, thus improving the efficiency of the genetic mapping experiments. These subclones may also be of value for deriving DNA sequence information at each locus, necessary for establishing polymerase chain reaction primers specific for each locus. Such information would allow the use of each locus as a sequence tagged site.

  15. Origin and Evolution of Y chromosomes: Drosophila tales

    Science.gov (United States)

    Carvalho, A. Bernardo; Koerich, Leonardo B.; Clark, Andrew G.

    2010-01-01

    Classically Y chromosomes are thought to originate from X chromosomes through a process of degeneration and gene loss. Now, the availability of 12 Drosophila genomes provides the opportunity to study the origin and evolution of Y chromosomes in an informative phylogenetic context. Surprisingly, the majority of Drosophila Y-linked genes are recent acquisitions from autosomes, and Y chromosome gene gains are more frequent than gene losses. Moreover, the D. pseudoobscura Y chromosome lacks homology with the Y of most Drosophila species. Thus the Drosophila Y has a different evolutionary history from canonical Y chromosomes (such as the mammalian Y), and it also might have a different origin. PMID:19443075

  16. Chromosome aberration analysis for biological dosimetry: a review

    International Nuclear Information System (INIS)

    Paul, S.F.D.; Venkatachalam, P.; Jeevanram, R.K.

    1996-01-01

    Among various biological dosimetry techniques, dicentric chromosome aberration method appears to be the method of choice in analysing accidental radiation exposure in most of the laboratories. The major advantage of this method is its sensitivity as the number of dicentric chromosomes present in control population is too small and more importantly radiation induces mainly dicentric chromosome aberration among unstable aberration. This report brings out the historical development of various cytogenetic methods, the basic structure of DNA, chromosomes and different forms of chromosome aberrations. It also highlights the construction of dose-response curve for dicentric chromosome and its use in the estimation of radiation dose. (author)

  17. Chromosomal phylogeny of Lagothrix, Brachyteles, and Cacajao.

    Science.gov (United States)

    Viegas Péquignot, E; Koiffmann, C P; Dutrillaux, B

    1985-01-01

    Based on a comparison of the karyotypes of two Plathyrrhini species, Cacajao melanocephalus (Pitheciinae) and Brachyteles arachnoides (Atelinae), with those of two previously studied species, Lagothrix lagothrica (Atelinae) and C calvus rubicundus (Pitheciinae), it appears that the two Cacajao species have undergone the same number of chromosome rearrangements since they diverged from their common ancestor and that the karyotype of Brachyteles is ancestral to that of Lagothrix. The chromosomal phylogeny of these four species is proposed. A Y-autosome translocation is present in the karyotypes of the two Cacajao species.

  18. DNA Repair Defects and Chromosomal Aberrations

    Science.gov (United States)

    Hada, Megumi; George, K. A.; Huff, J. L.; Pluth, J. M.; Cucinotta, F. A.

    2009-01-01

    Yields of chromosome aberrations were assessed in cells deficient in DNA doublestrand break (DSB) repair, after exposure to acute or to low-dose-rate (0.018 Gy/hr) gamma rays or acute high LET iron nuclei. We studied several cell lines including fibroblasts deficient in ATM (ataxia telangiectasia mutated; product of the gene that is mutated in ataxia telangiectasia patients) or NBS (nibrin; product of the gene mutated in the Nijmegen breakage syndrome), and gliomablastoma cells that are proficient or lacking in DNA-dependent protein kinase (DNA-PK) activity. Chromosomes were analyzed using the fluorescence in situ hybridization (FISH) chromosome painting method in cells at the first division post irradiation, and chromosome aberrations were identified as either simple exchanges (translocations and dicentrics) or complex exchanges (involving >2 breaks in 2 or more chromosomes). Gamma irradiation induced greater yields of both simple and complex exchanges in the DSB repair-defective cells than in the normal cells. The quadratic dose-response terms for both simple and complex chromosome exchanges were significantly higher for the ATM- and NBS-deficient lines than for normal fibroblasts. However, in the NBS cells the linear dose-response term was significantly higher only for simple exchanges. The large increases in the quadratic dose-response terms in these repair-defective cell lines points the importance of the functions of ATM and NBS in chromatin modifications to facilitate correct DSB repair and minimize the formation of aberrations. The differences found between ATM- and NBS-deficient cells at low doses suggest that important questions should with regard to applying observations of radiation sensitivity at high dose to low-dose exposures. For aberrations induced by iron nuclei, regression models preferred purely linear dose responses for simple exchanges and quadratic dose responses for complex exchanges. Relative biological effectiveness (RBE) factors of all of

  19. Temporal genomic evolution of bird sex chromosomes.

    Science.gov (United States)

    Wang, Zongji; Zhang, Jilin; Yang, Wei; An, Na; Zhang, Pei; Zhang, Guojie; Zhou, Qi

    2014-12-12

    Sex chromosomes exhibit many unusual patterns in sequence and gene expression relative to autosomes. Birds have evolved a female heterogametic sex system (male ZZ, female ZW), through stepwise suppression of recombination between chrZ and chrW. To address the broad patterns and complex driving forces of Z chromosome evolution, we analyze here 45 newly available bird genomes and four species' transcriptomes, over their course of recombination loss between the sex chromosomes. We show Z chromosomes in general have a significantly higher substitution rate in introns and synonymous protein-coding sites than autosomes, driven by the male-to-female mutation bias ('male-driven evolution' effect). Our genome-wide estimate reveals that the degree of such a bias ranges from 1.6 to 3.8 among different species. G + C content of third codon positions exhibits the same trend of gradual changes with that of introns, between chrZ and autosomes or regions with increasing ages of becoming Z-linked, therefore codon usage bias in birds is probably driven by the mutational bias. On the other hand, Z chromosomes also evolve significantly faster at nonsynonymous sites relative to autosomes ('fast-Z' evolution). And species with a lower level of intronic heterozygosities tend to evolve even faster on the Z chromosome. Further analysis of fast-evolving genes' enriched functional categories and sex-biased expression patterns support that, fast-Z evolution in birds is mainly driven by genetic drift. Finally, we show in species except for chicken, gene expression becomes more male-biased within Z-linked regions that have became hemizygous in females for a longer time, suggesting a lack of global dosage compensation in birds, and the reported regional dosage compensation in chicken has only evolved very recently. In conclusion, we uncover that the sequence and expression patterns of Z chromosome genes covary with their ages of becoming Z-linked. In contrast to the mammalian X chromosomes, such

  20. Evidence of chromosomal instability in neurofibromatosis

    International Nuclear Information System (INIS)

    Hafez, M.; Sharaf, L.; Abd el-Nabi, S.M.; el-Wehedy, G.

    1985-01-01

    Blood lymphocytes from six unrelated patients with neurofibromatosis and three normal controls were examined for their response to different doses (0, 75, 150, 300, 400 rad) of x-radiation, as measured by chromosome aberrations (gaps, breaks, dicentrics, centric rings, acentric ring, fragments, and minutes). Cytogenetic studies on phytohemagglutinin-stimulated cells revealed chromosomal instability in the neurofibromatosis lymphocytes as shown by the significant increase in the in the incidence of gaps, breaks and dicentrics. This increase paralleled the increase in the dose of irradiation. The significance of these findings is discussed

  1. Identification of novel translocation between short arm of chromosome 4 and long arm of chromosome 6 in an infertile man using Interphase Chromosome Profiling (ICP).

    Science.gov (United States)

    Kaul, S; Kaur, H; Vats, S K S; Chawla, J; Jindal, R; Khetarpal, P

    2018-02-07

    Conventional cytogenetics has always been a favourite to detect chromosomal aberrations. Carriers of chromosomal translocation are often phenotypically normal but are infertile. Couples are often advised to go for karyotyping, but culture failure or improper metaphase spread with poor banding often makes the analysis difficult. We report here a novel translocation between short arm of chromosome 4 and long arm of chromosome 6 in an infertile man using an advanced molecular cytogenetic technique of Interphase Chromosome Profiling (ICP). © 2018 Blackwell Verlag GmbH.

  2. 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.

  3. Microdissection and chromosome painting of X and B chromosomes in the grasshopper Eyprepocnemis plorans.

    Science.gov (United States)

    Teruel, M; Cabrero, J; Perfectti, F; Acosta, M J; Sánchez, A; Camacho, J P M

    2009-01-01

    The relative location of 2 repetitive DNAs, i.e. ribosomal (rDNA) and a tandemly repeated satellite DNA (satDNA), with respect to the centromere, suggested that B chromosomes in the grasshopper Eyprepocnemis plorans derived intraspecifically from the X chromosome. To test this hypothesis, we microdissected X and B chromosomes and amplified the obtained DNA by 2 different procedures, the conventional DOP-PCR method and the single-cell whole-genome amplification GenomePlex method. We then generated DNA probes to perform chromosome painting. Our results have confirmed that X and B chromosomes share many DNA sequences between them and with most of the autosomes, especially at locations where the satDNA and rDNA reside, in consistency with previous information. This supports the hypothesis of an intraspecific origin of B chromosomes in E. plorans. Nevertheless, the present results did not help to clarify whether Bs were derived from the X chromosome or else from 1 or more autosomes. (c) 2009 S. Karger AG, Basel.

  4. Nonhomologous DNA end joining and chromosome aberrations in human embryonic lung fibroblasts treated with environmental pollutants

    International Nuclear Information System (INIS)

    Rossner, Pavel; Rossnerova, Andrea; Beskid, Olena; Tabashidze, Nana; Libalova, Helena; Uhlirova, Katerina; Topinka, Jan; Sram, Radim J.

    2014-01-01

    Highlights: • We analyzed the effect of air pollutants on NHEJ and chromosome aberrations. • In HEL12469 cells B[a]P and extractable organic matter induced DSBs. • The compounds induced XRCC4 expression and a weak Ku70/80 response. • We found increased frequency of aberrations of chromosomes 1, 2, 4, 5, 7 and 17. • The tested compounds preferentially affected chromosome 7. - Abstract: In order to evaluate the ability of a representative polycyclic aromatic hydrocarbon (PAH) and PAH-containing complex mixtures to induce double strand DNA breaks (DSBs) and repair of damaged DNA in human embryonic lung fibroblasts (HEL12469 cells), we investigated the effect of benzo[a]pyrene (B[a]P) and extractable organic matter (EOM) from ambient air particles <2.5 μm (PM2.5) on nonhomologous DNA end joining (NHEJ) and induction of stable chromosome aberrations (CAs). PM2.5 was collected in winter and summer 2011 in two Czech cities differing in levels and sources of air pollutants. The cells were treated for 24 h with the following concentrations of tested chemicals: B[a]P: 1 μM, 10 μM, 25 μM; EOMs: 1 μg/ml, 10 μg/ml, 25 μg/ml. We tested several endpoints representing key steps leading from DSBs to the formation of CAs including histone H2AX phosphorylation, levels of proteins Ku70, Ku80 and XRCC4 participating in NHEJ, in vitro ligation activity of nuclear extracts of the HEL12469 cells and the frequency of stable CAs assessed by whole chromosome painting of chromosomes 1, 2, 4, 5, 7 and 17 using fluorescence in situ hybridization. Our results show that 25 μM of B[a]P and most of the tested doses of EOMs induced DSBs as indicated by H2AX phosphorylation. DNA damage was accompanied by induction of XRCC4 expression and an increased frequency of CAs. Translocations most frequently affected chromosome 7. We observed only a weak induction of Ku70/80 expression as well as ligation activity of nuclear extracts. In summary, our data suggest the induction of DSBs and

  5. A maximum likelihood algorithm for reconstructing 3D structures of human chromosomes from chromosomal contact data.

    Science.gov (United States)

    Oluwadare, Oluwatosin; Zhang, Yuxiang; Cheng, Jianlin

    2018-02-23

    The development of chromosomal conformation capture techniques, particularly, the Hi-C technique, has made the analysis and study of the spatial conformation of a genome an important topic in bioinformatics and computational biology. Aided by high-throughput next generation sequencing techniques, the Hi-C technique can generate genome-wide, large-scale intra- and inter-chromosomal interaction data capable of describing in details the spatial interactions within a genome. These data can be used to reconstruct 3D structures of chromosomes that can be used to study DNA replication, gene regulation, genome interaction, genome folding, and genome function. Here, we introduce a maximum likelihood algorithm called 3DMax to construct the 3D structure of a chromosome from Hi-C data. 3DMax employs a maximum likelihood approach to infer the 3D structures of a chromosome, while automatically re-estimating the conversion factor (α) for converting Interaction Frequency (IF) to distance. Our results show that the models generated by 3DMax from a simulated Hi-C dataset match the true models better than most of the existing methods. 3DMax is more robust to structural variability and noise. Compared on a real Hi-C dataset, 3DMax constructs chromosomal models that fit the data better than most methods, and it is faster than all other methods. The models reconstructed by 3DMax were consistent with fluorescent in situ hybridization (FISH) experiments and existing knowledge about the organization of human chromosomes, such as chromosome compartmentalization. 3DMax is an effective approach to reconstructing 3D chromosomal models. The results, and the models generated for the simulated and real Hi-C datasets are available here: http://sysbio.rnet.missouri.edu/bdm_download/3DMax/ . The source code is available here: https://github.com/BDM-Lab/3DMax . A short video demonstrating how to use 3DMax can be found here: https://youtu.be/ehQUFWoHwfo .

  6. Discontinuous gradient centrifugation (DGC) decreases the proportion of chromosomally unbalanced spermatozoa in chromosomal rearrangement carriers.

    Science.gov (United States)

    Rouen, Alexandre; Balet, Richard; Dorna, Maud; Hyon, Capucine; Pollet-Villard, Xavier; Chantot-Bastaraud, Sandra; Joyé, Nicole; Portnoï, Marie-France; Cassuto, Nino Guy; Siffroi, Jean-Pierre

    2013-07-01

    Can the proportion of unbalanced spermatozoa in chromosomal rearrangement carriers be decreased through the use of discontinuous gradient centrifugation (DGC)? DGC significantly decreases the proportion of genetically unbalanced spermatozoa in chromosomal rearrangement carriers. Chromosomal rearrangement carriers present with a certain proportion of unbalanced gametes, which can lead to miscarriages or malformations in the offspring. There is presently no known way to select the balanced spermatozoa and use them for IVF. The proportion of unbalanced spermatozoa after DGC was compared with that before DGC in 21 patients with a chromosomal rearrangement. At least 500 spermatozoa were analysed per observation. Twenty-one male patients with a chromosomal rearrangement were included in this prospective study. They initially consulted for infertility, recurrent miscarriages or a history of abnormal pregnancy. The samples were split into two, with one part undergoing DGC and the other being immediately fixed. Fluorescence in situ hybridization was performed to establish the chromosome segregation pattern of each spermatozoon. DGC significantly decreased the proportion of unbalanced spermatozoa in all but 1 of the 21 chromosomal rearrangement carriers (P < 0.05). Although DGC reduces the proportion of unbalanced spermatozoa in ejaculates from patients with chromosome rearrangements this elimination is only partial and some abnormal spermatozoa remain. Means to exclude these spermatozoa to ensure that only balanced ones are used in IVF remain to be discovered. The motility and morphology of the sperm before and after DGC were not measured. Used in IVF or intrauterine insemination, DGC could decrease the chance that a man carrying a chromosomal rearrangement will father an abnormal fetus.

  7. Tracking of chromosome and replisome dynamics in Myxococcus xanthus reveals a novel chromosome arrangement.

    Directory of Open Access Journals (Sweden)

    Andrea Harms

    Full Text Available Cells closely coordinate cell division with chromosome replication and segregation; however, the mechanisms responsible for this coordination still remain largely unknown. Here, we analyzed the spatial arrangement and temporal dynamics of the 9.1 Mb circular chromosome in the rod-shaped cells of Myxococcus xanthus. For chromosome segregation, M. xanthus uses a parABS system, which is essential, and lack of ParB results in chromosome segregation defects as well as cell divisions over nucleoids and the formation of anucleate cells. From the determination of the dynamic subcellular location of six genetic loci, we conclude that in newborn cells ori, as monitored following the ParB/parS complex, and ter regions are localized in the subpolar regions of the old and new cell pole, respectively and each separated from the nearest pole by approximately 1 µm. The bulk of the chromosome is arranged between the two subpolar regions, thus leaving the two large subpolar regions devoid of DNA. Upon replication, one ori region remains in the original subpolar region while the second copy segregates unidirectionally to the opposite subpolar region followed by the rest of the chromosome. In parallel, the ter region of the mother chromosome relocates, most likely passively, to midcell, where it is replicated. Consequently, after completion of replication and segregation, the two chromosomes show an ori-ter-ter-ori arrangement with mirror symmetry about a transverse axis at midcell. Upon completion of segregation of the ParB/parS complex, ParA localizes in large patches in the DNA-free subpolar regions. Using an Ssb-YFP fusion as a proxy for replisome localization, we observed that the two replisomes track independently of each other from a subpolar region towards ter. We conclude that M. xanthus chromosome arrangement and dynamics combine features from previously described systems with new features leading to a novel spatiotemporal arrangement pattern.

  8. Chromosomes in a genome-wise order: evidence for metaphase architecture.

    Science.gov (United States)

    Weise, Anja; Bhatt, Samarth; Piaszinski, Katja; Kosyakova, Nadezda; Fan, Xiaobo; Altendorf-Hofmann, Annelore; Tanomtong, Alongklod; Chaveerach, Arunrat; de Cioffi, Marcelo Bello; de Oliveira, Edivaldo; Walther, Joachim-U; Liehr, Thomas; Chaudhuri, Jyoti P

    2016-01-01

    One fundamental finding of the last decade is that, besides the primary DNA sequence information there are several epigenetic "information-layers" like DNA-and histone modifications, chromatin packaging and, last but not least, the position of genes in the nucleus. We postulate that the functional genomic architecture is not restricted to the interphase of the cell cycle but can also be observed in the metaphase stage, when chromosomes are most condensed and microscopically visible. If so, it offers the unique opportunity to directly analyze the functional aspects of genomic architecture in different cells, species and diseases. Another aspect not directly accessible by molecular techniques is the genome merged from two different haploid parental genomes represented by the homologous chromosome sets. Our results show that there is not only a well-known and defined nuclear architecture in interphase but also in metaphase leading to a bilateral organization of the two haploid sets of chromosomes. Moreover, evidence is provided for the parental origin of the haploid grouping. From our findings we postulate an additional epigenetic information layer within the genome including the organization of homologous chromosomes and their parental origin which may now substantially change the landscape of genetics.

  9. Morphological images analysis and chromosomic aberrations classification based on fuzzy logic

    International Nuclear Information System (INIS)

    Souza, Leonardo Peres

    2011-01-01

    This work has implemented a methodology for automation of images analysis of chromosomes of human cells irradiated at IEA-R1 nuclear reactor (located at IPEN, Sao Paulo, Brazil), and therefore subject to morphological aberrations. This methodology intends to be a tool for helping cytogeneticists on identification, characterization and classification of chromosomal metaphasic analysis. The methodology development has included the creation of a software application based on artificial intelligence techniques using Fuzzy Logic combined with image processing techniques. The developed application was named CHRIMAN and is composed of modules that contain the methodological steps which are important requirements in order to achieve an automated analysis. The first step is the standardization of the bi-dimensional digital image acquisition procedure through coupling a simple digital camera to the ocular of the conventional metaphasic analysis microscope. Second step is related to the image treatment achieved through digital filters application; storing and organization of information obtained both from image content itself, and from selected extracted features, for further use on pattern recognition algorithms. The third step consists on characterizing, counting and classification of stored digital images and extracted features information. The accuracy in the recognition of chromosome images is 93.9%. This classification is based on classical standards obtained at Buckton [1973], and enables support to geneticist on chromosomic analysis procedure, decreasing analysis time, and creating conditions to include this method on a broader evaluation system on human cell damage due to ionizing radiation exposure. (author)

  10. A novel MCPH1 isoform complements the defective chromosome condensation of human MCPH1-deficient cells.

    Directory of Open Access Journals (Sweden)

    Ioannis Gavvovidis

    Full Text Available Biallelic mutations in MCPH1 cause primary microcephaly (MCPH with the cellular phenotype of defective chromosome condensation. MCPH1 encodes a multifunctional protein that notably is involved in brain development, regulation of chromosome condensation, and DNA damage response. In the present studies, we detected that MCPH1 encodes several distinct transcripts, including two major forms: full-length MCPH1 (MCPH1-FL and a second transcript lacking the six 3' exons (MCPH1Δe9-14. Both variants show comparable tissue-specific expression patterns, demonstrate nuclear localization that is mediated independently via separate NLS motifs, and are more abundant in certain fetal than adult organs. In addition, the expression of either isoform complements the chromosome condensation defect found in genetically MCPH1-deficient or MCPH1 siRNA-depleted cells, demonstrating a redundancy of both MCPH1 isoforms for the regulation of chromosome condensation. Strikingly however, both transcripts are regulated antagonistically during cell-cycle progression and there are functional differences between the isoforms with regard to the DNA damage response; MCPH1-FL localizes to phosphorylated H2AX repair foci following ionizing irradiation, while MCPH1Δe9-14 was evenly distributed in the nucleus. In summary, our results demonstrate here that MCPH1 encodes different isoforms that are differentially regulated at the transcript level and have different functions at the protein level.

  11. Identification of a structural chromosomal rearrangement in the karyotype of a root vole from Chernobyl

    International Nuclear Information System (INIS)

    Nadzhafova, R.S.; Bulatova, N.Sh.; Kozlovskii, A.I.; Ryabov, I.N.

    1994-01-01

    Karyological studies of rodents within a 30-km radius of the Chernobyl nuclear power plant revealed one female root vole (Microtus oeconomus) with an abnormal karyotype. The use of C, G, and AgNOR banding methods allowed determination that morphological changes in two nonhomologous autosomes, which were accompanied by rearrangements in distribution of G bands, heterochromatin, and NOR, are the result of a reciprocal translocation. Chromosomal aberrations were probably inherited or appeared in embryogenesis, since none of the analyzed cells of the studied vole had a normal karyotype. It is important to note that this rearrangement was detected five years after the meltdown. Both breaks and reunions of the chromosomes that participate in this rearrangement are probably located in regions that are not important for functioning of these chromosomes. Thus, it can be supposed that the detected rearrangement did not influence the viability of the vole. This karyotype was compared to a standard karyotype of a root vole from another area of the species range. The heteromorphism of the first pair of chromosomes in both voles, which was detected for the first time, is probably normal for the karyotype of M. oeconomus and is not linked with any radiation-induced intrachromosomal aberrations

  12. Leptotene/zygotene chromosome movement via the SUN/KASH protein bridge in Caenorhabditis elegans.

    Science.gov (United States)

    Baudrimont, Antoine; Penkner, Alexandra; Woglar, Alexander; Machacek, Thomas; Wegrostek, Christina; Gloggnitzer, Jiradet; Fridkin, Alexandra; Klein, Franz; Gruenbaum, Yosef; Pasierbek, Pawel; Jantsch, Verena

    2010-11-24

    The Caenorhabditis elegans inner nuclear envelope protein matefin/SUN-1 plays a conserved, pivotal role in the process of genome haploidization. CHK-2-dependent phosphorylation of SUN-1 regulates homologous chromosome pairing and interhomolog recombination in Caenorhabditis elegans. Using time-lapse microscopy, we characterized the movement of matefin/SUN-1::GFP aggregates (the equivalent of chromosomal attachment plaques) and showed that the dynamics of matefin/SUN-1 aggregates remained unchanged throughout leptonene/zygotene, despite the progression of pairing. Movement of SUN-1 aggregates correlated with chromatin polarization. We also analyzed the requirements for the formation of movement-competent matefin/SUN-1 aggregates in the context of chromosome structure and found that chromosome axes were required to produce wild-type numbers of attachment plaques. Abrogation of synapsis led to a deceleration of SUN-1 aggregate movement. Analysis of matefin/SUN-1 in a double-strand break deficient mutant revealed that repair intermediates influenced matefin/SUN-1 aggregate dynamics. Investigation of movement in meiotic regulator mutants substantiated that proper orchestration of the meiotic program and effective repair of DNA double-strand breaks were necessary for the wild-type behavior of matefin/SUN-1 aggregates.

  13. Malassezia-derived indoles activate the aryl hydrocarbon receptor and inhibit Toll-like receptor-induced maturation in monocyte-derived dendritic cells.

    NARCIS (Netherlands)

    Vlachos, C.; Schulte, B.M.; Magiatis, P.; Adema, G.J.; Gaitanis, G.

    2012-01-01

    Background The aryl hydrocarbon receptor (AhR) is a nuclear receptor and transcriptional regulator with pleiotropic effects. The production of potent AhR ligands by Malassezia yeasts, such as indirubin, indolo[3,2-b]carbazole (ICZ), tryptanthrin and malassezin, has been associated with the

  14. Chromatin Conformation Capture-Based Analysis of Nuclear Architecture.

    Science.gov (United States)

    Grob, Stefan; Grossniklaus, Ueli

    2017-01-01

    Nuclear organization and higher-order chromosome structure in interphase nuclei are thought to have important effects on fundamental biological processes, including chromosome condensation, replication, and transcription. Until recently, however, nuclear organization could only be analyzed microscopically. The development of chromatin conformation capture (3C)-based techniques now allows a detailed look at chromosomal architecture from the level of individual loci to the entire genome. Here we provide a robust Hi-C protocol, allowing the analysis of nuclear organization in nuclei from different wild-type and mutant plant tissues. This method is quantitative and provides a highly efficient and comprehensive way to study chromatin organization during plant development, in response to different environmental stimuli, and in mutants disrupting a variety of processes, including epigenetic pathways regulating gene expression.

  15. New St-chromosome-specific molecular markers for identifying ...

    Indian Academy of Sciences (India)

    chromosome-specific PLUG and SCAR markers, and successfully used them to detect the St-chromosome in wheat–Th. intermedium introgression lines. Materials and methods. Plant materials. Wheat line ML13 was provided by International Maize and.

  16. The value of chromosomal analysis in oligozoospermic men

    NARCIS (Netherlands)

    Stegen, Çarcia; van Rumste, Minouche M. E.; Mol, Ben Willem J.; Koks, Carolien A. M.

    2012-01-01

    Objective: To determine the prevalence of chromosomal abnormalities in relation to sperm concentration in subfertile oligozoospermic men. Design: Retrospective cohort study. Setting: Two teaching hospitals. Patient(s): We retrospectively studied all men who received chromosomal analysis prior to

  17. Mapping and ordered cloning of the human X chromosome

    Energy Technology Data Exchange (ETDEWEB)

    Caskey, C.T.; Nelson, D.L.

    1992-12-01

    Progress is reported on gathering X chromosome specific libraries and integrating those with the library produced in this project. Further studies on understanding Fragile X Syndrome and other hereditary diseases related to the X chromosome are described. (DT)

  18. Learning Disabilities in Children with Sex Chromosome Anomalies.

    Science.gov (United States)

    Pennington, Bruce F.; And Others

    1982-01-01

    Results obtained from 44 children (ages 7 through 16) with sex chromosome abnormalities and from 17 chromosomally normal siblings demonstrated that children in the former group have an increased risk of encountering learning problems. (MP)

  19. Frequency of congenital malformations and chromosomal disorders ...

    Indian Academy of Sciences (India)

    2015-12-03

    Dec 3, 2015 ... are different in area, number of inhabitants, level of economic and social development, etc. The data ... [Popa C.-E. and Ghiorghit˘a G. 2015 Frequency of congenital malformations and chromosomal disorders in Bacau and Vaslui counties .... avoiding an abnormal neuro-motor development of a child.

  20. Association of recurrent pregnancy loss with chromosomal ...

    African Journals Online (AJOL)

    Objective: To evaluate the association of parental and fetal chromosomal abnormalities with recurrent pregnancy loss in our area and to analyze the frequency of three types of hereditary thrombophilia's; (MTHFR C677T polymorphisms, FV Leiden G1691A mutation and Prothrombin (factor II) G20210A mutation) in these ...

  1. Partial Duplication of Chromosome 8p

    African Journals Online (AJOL)

    rme

    duplication.13,23-29. A number of authors suggested that a candidate gene/or a cluster of genes located in 8p23 region behaves as a dominant mutation that .... Partial trisomy of short arm of chromosome 8 (46,XY, inv dup (8) (p21- ->pter) in a Bedouin child with multiple congenital anomalies and mental retardation.

  2. Frequency of congenital malformations and chromosomal disorders ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Genetics; Volume 94; Issue 4 ... congenital malformations; chromosomal disorders; frequency; human populations. Abstract. This paper presents the state of genetic health of the human populations in two Romanian counties, Bacau and Vaslui, as they are different in area, number of inhabitants, ...

  3. The chromosomes Damaliscus lunatus of the tsessebe

    African Journals Online (AJOL)

    data and must be related to a factor other than substrate. Forbes (1973a) postulated that water movement and .... with masking tape. Specimens were delivered to the laboratory within 6 h and kept at 4°C until processed. Whole blood was used for leucocyte culture. Chromosome preparations were made according to the.

  4. IAPT/IOPB chromosome data 20

    Czech Academy of Sciences Publication Activity Database

    Altinordu, F.; Šumberová, Kateřina; Ankova, T.; Erst, A. S.; Kuzmin, I. V.; Shaulo, D. N.; Plugatar, Y. V.; Baltisberger, M.; Deldago, L.; Gallego Martín, F.; Rico, E.; Lavia, G. I.; Krapovickas, A.; de los Angeles Martines, M.; Lazaroff, Y.; Solis Neffa, V. G.; Ortiz, A. M.; Sivestri, M. C.; Pavlova, D.; Bani, A.; Polido, C. A.; Moraes, A. P.; Forni-Martins, E. R.; Probatova, N. S.; Kazanovsky, S. G.; Barkalov, V. Y.; Rudyka, E. G.; Shatokhina, A. V.; Krivenko, D. A.; Verkhozina, A. V.; Nechaev, V. A.; Romero-da Cruz, M. V.; Wefferling, K. M.; Owen, H. A.; Hoot, S. B.

    2015-01-01

    Roč. 64, č. 6 (2015), s. 1344-1350 ISSN 0040-0262 R&D Projects: GA ČR GB14-36079G Institutional support: RVO:67985939 Keywords : chromosome count * plants Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.907, year: 2015

  5. Human oocyte chromosome analyses need a standardized ...

    Indian Academy of Sciences (India)

    Studies of DNA polymorphisms in human trisomic abor- tions and liveborn have revealed a chromosome-specific vari- ation in the importance of meiosis I versus meiosis II er- rors. As a general rule, maternal meiosis I errors predom- inate among almost all trisomies (Hassold and Hunt 2001). It is evident that a direct ...

  6. Morphology and chromosome numbers of Gongronema latifolia ...

    African Journals Online (AJOL)

    Cytological studies on the root-tips of four clones of Gongronema latifolia Benth. were conducted to identify cross-compatible clones for possible improvement through hybridisation. The results showed that the diploid chromosomes number in G. latifolia was 2n = 16. Clones, IMS-20-NJIABA, AKS-33-EKPENE EDIENE, ...

  7. 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

  8. Genetics Home Reference: ring chromosome 14 syndrome

    Science.gov (United States)

    ... learning problems. Development may be delayed, particularly the development of speech and of motor skills such as sitting, standing, and walking. Additional features of ring chromosome 14 syndrome can include slow growth and short stature, a small head ( microcephaly ), puffy hands and/or feet caused ...

  9. Chromosomal aberrations induced by Markhamia tomentosa (Benth ...

    African Journals Online (AJOL)

    Markhamia tomentosa (Benth.) K. Schum. Ex Engl. (Bignoniaceae) is used traditionally in the treatment of pain, oedema, pulmonary troubles and cancer. The genotoxic and cytotoxic effects of the ethanolic extract of the leaves of M. tomentosa was investigated using the Allium cepa root chromosomal aberration assay.

  10. Chromosome 22 microdeletion in children with syndromic ...

    African Journals Online (AJOL)

    Cytogenetic study and fluorescence in situ hybridization (FISH) were performed in the patients. The study revealed that 2 patients were with chromosomal aberrations [one with 46,XY, add (13)(p13) & the other with 47,XX,+13]. In addition, FISH revealed 4 patients (20%) with 22q11.2 microdeletion syndrome. The congenital ...

  11. RESEARCH ARTICLE Y chromosome polymorphisms of the ...

    Indian Academy of Sciences (India)

    2017-02-10

    Feb 10, 2017 ... Kolmogorov-Smirnov test using SPSS 17.0 software (SPSS Inc., Chicago, IL). Results. SNP detection. The male specificity for PCR amplification of 29 pairs of primers was confirmed. For the. PCR products of the vast majority of primers, all of the samples carried the same. Y-chromosome haplotype ...

  12. Psychoeducational Implications of Sex Chromosome Anomalies

    Science.gov (United States)

    Wodrich, David L.; Tarbox, Jennifer

    2008-01-01

    Numerous anomalies involving the sex chromosomes (X or Y) have been documented and their impact on development, learning, and behavior studied. This article reviews three of these disorders, Turner syndrome, Klinefelter syndrome, and Lesch-Nyhan disease. Each of these three is associated with one or more selective impairments or behavioral…

  13. Insect chromosomes preparing methods for genetic researches ...

    African Journals Online (AJOL)

    Cytogenetics are almost always based on the examination of the fixed mitotic chromosomes during the analyses of metaphase. During this phase of the cycle of cells, the DNA is folded up and chromatin is strongly condensed. The relative position of the centromere is constant, which means that the ratio of the lengths of the ...

  14. Plasmid and chromosome segregation in prokaryotes

    DEFF Research Database (Denmark)

    Møller-Jensen, Jakob; Bugge Jensen, Rasmus; Gerdes, Kenn

    2000-01-01

    Recent major advances in the understanding of prokaryotic DNA segregation have been achieved by using fluorescence microscopy to visualize the localization of cellular components. Plasmids and bacterial chromosomes are partitioned in a highly dynamic fashion, suggesting the presence of a mitotic...

  15. Nondisjunction of chromosome 15: Origin and recombination

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, W.P.; Bernasconi, F.; Schinzel, A.A.; Mutirangura, A.; Ledbetter, D.H. (Baylor College of Medicine, Houston, TX (United States)); Langlois, S. (Univ. of Britisch Columbia, Vancouver (Canada)); Morris, M.A.; Malcolm, S.

    1993-09-01

    Thirty-two cases of uniparental disomy (UPD), ascertained from Prader-Willi syndrome patients (N=27) and Angelman syndrome patients (N-5), are used to investigate the pattern of recombination associated with nondisjunction of chromosome 15. In addition, the meiotic stage of nondisjunction is inferred by using markers mapping near the centromere. Two basic approaches to the analysis of recombination in specific pairwise intervals along the chromosome. This method shows a significant reduction in recombination for two of five intervals examined. Second, the observed frequency of each recombinant class (i.e., zero, one, two, three, or more observable crossovers) is compared with expected values. This is useful for testing whether the reduction in recombination can be attributed solely to a proportion of cases with no recombination at all (because of asynapsis), with the remaining groups showing normal recombination (or even excess recombination), or whether recombination is uniformly reduced. Analysis of maternal UPD(15) data shows a slight reduction in the multiple-recombinant classes, with a corresponding increase in both the zero- and one-recombinant classes over expected values. The majority, more than 82%, of the extra chromosomes in maternal UPD(15) cases are due to meiotic I nondisjunction events. In contrast, more paternal UPD(15) cases so far examined appear to have a postzygotic origin of the extra paternal chromosome. 33 refs., 1 fig., 7 tabs.

  16. Chromosomes and plant cell division in space

    Science.gov (United States)

    Krikorian, A. D.

    1988-01-01

    The objectives were: examination of chromosomal aberrations; development of an experimental system; and engineering design units (EDUs) evaluation. Evaluation criteria are presented. Procedures were developed for shuttle-based investigations which result in the procurement of plant root tips for subsequent cytological examination.

  17. Chromosome Conformation Capture on Chip (4C)

    DEFF Research Database (Denmark)

    Leblanc, Benjamin Olivier; Comet, Itys; Bantignies, Frédéric

    2016-01-01

    4C methods are useful to investigate dependencies between regulatory mechanisms and chromatin structures by revealing the frequency of chromatin contacts between a locus of interest and remote sequences on the chromosome. In this chapter we describe a protocol for the data analysis of microarray-...... to analyze ChIP-on-chip data on broadly distributed chromatin components such as histone marks....

  18. Progressive segregation of the Escherichia coli chromosome

    DEFF Research Database (Denmark)

    Nielsen, Henrik Jørck; Youngren, Brenda; Hansen, Flemming G.

    2006-01-01

    We have followed the fate of 14 different loci around the Escherichia coli chromosome in living cells at slow growth rate using a highly efficient labelling system and automated measurements. Loci are segregated as they are replicated, but with a marked delay. Most markers segregate in a smooth...

  19. MORPHOLOGY AND CHROMOSOME NUMBERS OF Gongronema ...

    African Journals Online (AJOL)

    journal

    Cytological studies on the root-tips of four clones of Gongronema latifolia Benth. were conducted to identify cross-compatible clones for possible improvement through hybridisation. The results showed that the diploid chromosomes number in G. latifolia was 2n = 16. Clones, IMS-20-NJIABA, AKS-33-EKPENE EDIENE, ANS-.

  20. Determination of chromosomes that control physiological traits ...

    African Journals Online (AJOL)

    Determination of chromosomes that control physiological traits associated with salt tolerance in barley at the seedling stage. ... The phenotypic traits under study included: chlorophyll contents, chlorophyll fluorescence (Fo, Fv, Fv/Fm), proline and carbohydrate rates, relative water content (RWC) and dry and wet weight of ...

  1. MORPHOLOGY AND CHROMOSOME NUMBERS OF Gongronema ...

    African Journals Online (AJOL)

    journal

    Morphology and chromosome numbers than one nucleus per cell (Partanen, 1963). Polyploidy in some instances is advantageous as it affects plant part sizes like larger leaf areas, flowers and fruits (Walker et al. 2005; El-. Ferchichi et al. 2006; Samiha et al. 2009). The higher number of viable seeds per follicle and matured ...

  2. How to Protect the Chromosomal Ends?

    Indian Academy of Sciences (India)

    The 2009 Nobel Prize in Physiology or Medicine was jointly awarded to three scientists – Elizabeth H Blackburn, Carol W. Greider and Jack W Szostak – for their work during early. 1980s and 1990s which helped unravel the molecular mecha- nisms of protection of chromosomal ends by telomeres and the enzyme ...

  3. Somatic chromosomal abnormalities in couples undergoing infertility ...

    Indian Academy of Sciences (India)

    1996; Johnson 1998). Consid- ering pooled data obtained from more than 9000 azoosper- mic and oligozoospermic men, a 5.8% incidence of chromo- somal abnormalities has been found. Of these, 4.2% affect the gonosomes and 1.5% the autosomes, respectively (John- son 1998). In detail, sex chromosome anomalies ...

  4. IAPT/IOPB chromosome data 25 - Asteraceae

    Czech Academy of Sciences Publication Activity Database

    Krahulcová, Anna

    2017-01-01

    Roč. 66, č. 5 (2017), s. 1249-1249 ISSN 0040-0262 Institutional support: RVO:67985939 Keywords : chromosome numbers * DNA ploidy level * anginosperms Subject RIV: EF - Botanics OBOR OECD: Plant sciences, botany Impact factor: 2.447, year: 2016

  5. Fetal chromosome abnormalities and congenital malformations: an ...

    African Journals Online (AJOL)

    Objective: Our objective were to determine and evaluate the role of genetic counseling and amniocentesis in early detection of chromosomal abnormalities or congenital malformations among women at risk. Patients and Methods: The study was performed on 784 pregnant women. Results: The cause for seeking genetic ...

  6. Improved prenatal detection of chromosomal anomalies

    DEFF Research Database (Denmark)

    Frøslev-Friis, Christina; Hjort-Pedersen, Karina; Henriques, Carsten U

    2011-01-01

    Prenatal screening for karyotype anomalies takes place in most European countries. In Denmark, the screening method was changed in 2005. The aim of this study was to study the trends in prevalence and prenatal detection rates of chromosome anomalies and Down syndrome (DS) over a 22-year period....

  7. Monosomic analysis reveals duplicated chromosomal segments in ...

    Indian Academy of Sciences (India)

    g bg. GGg or. Golden plant. –. bGg, GGGg. –, Indicates the absence of dominant allele (due to nondisjunction of chromosome carrying dominant allele) in the egg cell (female gamete) and consequently creating hemizygous condition in the embryos of monosomic plants. Journal of Genetics, Vol. 88, No. 3, December 2009.

  8. Intraspecific chromosomal and genetic polymorphism in Brassica ...

    Indian Academy of Sciences (India)

    2014-04-16

    Apr 16, 2014 ... A. V., Lemesh V. A. and Muravenko O. V. 2014 Intraspecific chromosomal and genetic polymorphism in Brassica napus L. detected by cytogenetic and molecular markers. J. Genet. ...... Howell E. C., Kearsey M. J., Jones G. H., King G. J. and Armstrong. S. J. 2008 A and C genome distinction and ...

  9. Radiation hybrid mapping of chromosome 5

    International Nuclear Information System (INIS)

    Warrington, J.A.; Hall, L.V.; Plummer, S.; Wasmuth, J.; Robbins, S.; Miller, J.N.; Lovett, M.

    1990-01-01

    The authors have constructed a physical map for 12 loci from the q21-q33 region of human chromosome 5 using the method of radiation hybrid mapping. A panel of irradiation hybrids containing fragments of human chromosome 5q was generated from an HPRT + Chinese hamster-human cell line containing a chromosome t(4;5) 5qter-5p15.1::4p15.1-4pter as its only human material. After irradiation of the donor line at 6,500 rads and subsequent fusion with a non-irradiated HPRT - Chinese hamster line, HAT selection yielded 226 clones which were not under any selective pressure to retain human DNA. These clones were then screened for the presence of human DNA by human specific repeat sequence PCR, with 109 hybrids showing some human material. By analyzing the cosegregation of the human markers in hybrid clones, they were able to construct a physical map defining the order and distance between the thirteen loci, which span a genetic distance of about 26 cM and a physical distance estimated to be 26 million pb. This physical map will aid in the ordering of yeast artificial chromosome clones, and the establishment of contigs in this region

  10. Microsatellite and Chromosomal Instability in Breast Cancer

    National Research Council Canada - National Science Library

    Baranovskaya, Svetlana

    2004-01-01

    ... in the pathogenesis of several types of human cancers. They found that 22% of all breast cancer cases have allelic imbalances in one or more of 14 microsatellite markers, which covered a region of 21MB of chromosome 7 around the EGFR gene...

  11. Transcript variations, phylogenetic tree and chromosomal ...

    Indian Academy of Sciences (India)

    AGNIESZKA SADOWSKA

    4Department of Genetics and Animal Breeding, Poznan University of Life Science, Wolynska 33, 60-637 Poznan, Poland. Abstract ... and Ciereszko R. E. 2017 Transcript variations, phylogenetic tree and chromosomal localization of porcine aryl hydrocarbon receptor (AhR) .... Assembling and mapping of the obtained con-.

  12. Chromosomal evolution and phylogenetic analyses in Tayassu ...

    Indian Academy of Sciences (India)

    lymphocyte cultures of whole blood samples using standard protocols (Chaves et al. 2002). The karyotype of T. pecari (individuals from South. America) has 26 chromosomes, with the two largest chro- mosome pairs being submetacentric, nine pairs metacen- tric/submetacentric, the smallest autosomal pair acrocentric,.

  13. Insect chromosomes preparing methods for genetic researches

    African Journals Online (AJOL)

    STORAGESEVER

    2009-01-05

    Jan 5, 2009 ... Cytogenetics are almost always based on the examination of the fixed mitotic chromosomes during the analyses of metaphase. During this phase of the cycle of cells, the DNA is folded up and chromatin is strongly condensed. The relative position of the centromere is constant, which means that the ratio of.

  14. The map of chromosome 1 of man

    NARCIS (Netherlands)

    W.G. Burgerhout (Wim)

    1977-01-01

    textabstractMaking maps is an essential procedure in the exploration of new territories. In the field of genetics, many basic concepts concerning the structure of a genome and the regulation of gene activity have emerged from regional mapping studies on the chromosomes of e.g. Escherichia coli

  15. The genomics of plant sex chromosomes

    Czech Academy of Sciences Publication Activity Database

    Vyskot, Boris; Hobza, Roman

    2015-01-01

    Roč. 236, JUL 2015 (2015), s. 126-135 ISSN 0168-9452 R&D Projects: GA ČR(CZ) GBP501/12/G090; GA ČR(CZ) GAP501/12/2220 Institutional support: RVO:68081707 Keywords : Y-CHROMOSOME * SILENE-LATIFOLIA * DIOECIOUS PLANT Subject RIV: BO - Biophysics Impact factor: 3.362, year: 2015

  16. Ring Chromosome 7 in an Indian Woman

    Science.gov (United States)

    Kaur, Anupam; Dhillon, Sumit; Garg, P. D.; Singh, Jai Rup

    2008-01-01

    Background: Ring chromosome 7 [r(7)] is a rare cytogenetic aberration, with only 16 cases (including 3 females) reported in the literature to date. This is the first reported case of r(7) from India. Method: Clinical and cytogenetic investigations were carried out in an adult female with microcephaly and intellectual disability. Results: Ring…

  17. Analysis of chromosome termini in potato varieties

    Czech Academy of Sciences Publication Activity Database

    Fajkus, Jiří; Novotná, Marcela; Ptáček, J.

    2002-01-01

    Roč. 48, č. 11 (2002), s. 477-479 ISSN 0370-663X R&D Projects: GA MZe QC1164; GA ČR GA204/02/0027 Institutional research plan: CEZ:AV0Z5004920 Keywords : plant chromosomes * telomere lenght * potato varieties Subject RIV: BO - Biophysics Impact factor: 0.333, year: 2002

  18. Cytogenetic characterization and AFLP-based genetic linkage mapping for the butterfly Bicyclus anynana, covering all 28 karyotyped chromosomes.

    Directory of Open Access Journals (Sweden)

    Arjen E Van't Hof

    Full Text Available BACKGROUND: The chromosome characteristics of the butterfly Bicyclus anynana, have received little attention, despite the scientific importance of this species. This study presents the characterization of chromosomes in this species by means of cytogenetic analysis and linkage mapping. METHODOLOGY/PRINCIPAL FINDINGS: Physical genomic features in the butterfly B. anynana were examined by karyotype analysis and construction of a linkage map. Lepidoptera possess a female heterogametic W-Z sex chromosome system. The WZ-bivalent in pachytene oocytes of B. anynana consists of an abnormally small, heterochromatic W-chromosome with the Z-chromosome wrapped around it. Accordingly, the W-body in interphase nuclei is much smaller than usual in Lepidoptera. This suggests an intermediate stage in the process of secondary loss of the W-chromosome to a ZZ/Z sex determination system. Two nucleoli are present in the pachytene stage associated with an autosome and the WZ-bivalent respectively. Chromosome counts confirmed a haploid number of n = 28. Linkage mapping had to take account of absence of crossing-over in females, and of our use of a full-sib crossing design. We developed a new method to determine and exclude the non-recombinant uninformative female inherited component in offspring. The linkage map was constructed using a novel approach that uses exclusively JOINMAP-software for Lepidoptera linkage mapping. This approach simplifies the mapping procedure, avoids over-estimation of mapping distance and increases the reliability of relative marker positions. A total of 347 AFLP markers, 9 microsatellites and one single-copy nuclear gene covered all 28 chromosomes, with a mapping distance of 1354 cM. Conserved synteny of Tpi on the Z-chromosome in Lepidoptera was confirmed for B. anynana. The results are discussed in relation to other mapping studies in Lepidoptera. CONCLUSIONS/SIGNIFICANCE: This study adds to the knowledge of chromosome structure and

  19. Nuclear medicine

    International Nuclear Information System (INIS)

    Lentle, B.C.

    1986-01-01

    Several growth areas for nuclear medicine were defined. Among them were: cardiac nuclear medicine, neuro-psychiatric nuclear medicine, and cancer diagnosis through direct tumor imaging. A powerful new tool, Positron Emission Tomography (PET) was lauded as the impetus for new developments in nuclear medicine. The political environment (funding, degree of autonomy) was discussed, as were the economic and scientific environments

  20. Identification of Chromosomes Alterations in Primary Breast Cancer Using Premature Chromosome Condensation

    National Research Council Canada - National Science Library

    Griffin, Constance

    2000-01-01

    .... We are developing a new method, premature chromosome condensation (PCC),using mitotic Xenopus extracts that will allow us to obtain G-banded karyotypes from primary, uncultured breast cancer specimens...

  1. Chromosomes of South American Bufonidae (Amphibia, Anura Chromosomes of South American Bufonidae (Amphibia, Anura

    Directory of Open Access Journals (Sweden)

    Brum Zorrilla N.

    1973-09-01

    Full Text Available Karyotypes of eight of South American Bufonidae were studied: B.ictericus, B. spinulosus spinulosus, B. arenarum, B. g. fernandezae, B. g. d'orbignyi, B. crucifer, B. paracnemis and B. marinus. In all species 2n = 22 chromosomes were found. Neither heteromorphic pairs of chromosomes nor bivalents with characteristic morphology and behavior of sex chromosomesduring male meiosis were observed in any species.Karyotypes of eight of South American Bufonidae were studied: B.ictericus, B. spinulosus spinulosus, B. arenarum, B. g. fernandezae, B. g. d'orbignyi, B. crucifer, B. paracnemis and B. marinus. In all species 2n = 22 chromosomes were found. Neither heteromorphic pairs of chromosomes nor bivalents with characteristic morphology and behavior of sex chromosomesduring male meiosis were observed in any species.

  2. Chromosomes as well as chromosomal subdomains constitute distinct units in interphase nuclei

    NARCIS (Netherlands)

    Visser, A. E.; Aten, J. A.

    1999-01-01

    Fluorescence in situ hybridization has demonstrated that chromosomes form individual territories in interphase nuclei. However, this technique is not suitable to determine whether territories are mutually exclusive or interwoven. This notion, however, is essential for understanding functional

  3. Neo-sex chromosomes in the black muntjac recapitulate incipient evolution of mammalian sex chromosomes

    DEFF Research Database (Denmark)

    Zhou, Qi; Wang, Jun; Huang, Ling

    2008-01-01

    BACKGROUND: The regular mammalian X and Y chromosomes diverged from each other at least 166 to 148 million years ago, leaving few traces of their early evolution, including degeneration of the Y chromosome and evolution of dosage compensation. RESULTS: We studied the intriguing case of black...... muntjac, in which a recent X-autosome fusion and a subsequent large autosomal inversion within just the past 0.5 million years have led to inheritance patterns identical to the traditional X-Y (neo-sex chromosomes). We compared patterns of genome evolution in 35-kilobase noncoding regions and 23 gene...... pairs on the homologous neo-sex chromosomes. We found that neo-Y alleles have accumulated more mutations, comprising a wide variety of mutation types, which indicates cessation of recombination and is consistent with an ongoing neo-Y degeneration process. Putative deleterious mutations were observed...

  4. 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...... analyses for 13 loci on 21q. Nine of 11 r(21)s, including the 5 familial r(21)s, showed no evidence for duplication of 21q sequences but did show molecular evidence of partial deletion of 21q. These data were consistent with the breakage and reunion of short- and long-arm regions to form the r(21......). 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....

  5. Heteromorphic Sex Chromosomes: Navigating Meiosis without a Homologous Partner

    OpenAIRE

    Checchi, Paula M.; Engebrecht, JoAnne

    2011-01-01

    Accurate chromosome segregation during meiosis relies on homology between the maternal and paternal chromosomes. Yet by definition, sex chromosomes of the heterogametic sex lack a homologous partner. Recent studies in a number of systems have shed light on the unique meiotic behavior of heteromorphic sex chromosomes, and highlight both the commonalities and differences in divergent species. During meiotic prophase, the homology-dependent processes of pairing, synapsis, and recombination have ...

  6. Updating the maize karyotype by chromosome DNA sizing.

    Directory of Open Access Journals (Sweden)

    Jéssica Coutinho Silva

    Full Text Available The karyotype is a basic concept regarding the genome, fundamentally described by the number and morphological features of all chromosomes. Chromosome class, centromeric index, intra- and interchromosomal asymmetry index, and constriction localization are important in clinical, systematic and evolutionary approaches. In spite of the advances in karyotype characterization made over the last years, new data about the chromosomes can be generated from quantitative methods, such as image cytometry. Therefore, using Zea mays L., this study aimed to update the species' karyotype by supplementing information on chromosome DNA sizing. After adjustment of the procedures, chromosome morphometry and class as well as knob localization enabled describing the Z. mays karyotype. In addition, applying image cytometry, DNA sizing was unprecedentedly measured for the arms and satellite of all chromosomes. This way, unambiguous identification of the chromosome pairs, and hence the assembly of 51 karyograms, were only possible after the DNA sizing of each chromosome, their arms and satellite portions. These accurate, quantitative and reproducible data also enabled determining the distribution and variation of DNA content in each chromosome. From this, a correlation between DNA amount and total chromosome length evidenced that the mean DNA content of chromosome 9 was higher than that of chromosome 8. The chromosomal DNA sizing updated the Z. mays karyotype, providing insights into its dynamic genome with regards to the organization of the ten chromosomes and their respective portions. Considering the results and the relevance of cytogenetics in the current scenario of comparative sequencing and genomics, chromosomal DNA sizing should be incorporated as an additional parameter for karyotype definition. Based on this study, it can be affirmed that cytogenetic approaches go beyond the simple morphological description of chromosomes.

  7. High degree of sex chromosome differentiation in stickleback fishes

    OpenAIRE

    Shikano, Takahito; Natri, Heini M; Shimada, Yukinori; Meril?, Juha

    2011-01-01

    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...

  8. Identification of Prostate Cancer Predisposition Genes on the Y Chromosome

    Science.gov (United States)

    2017-10-01

    AWARD NUMBER: W81XWH -15 -1-0638 TITLE: Identification of Prostate Cancer Predisposition Genes on the Y Chromosome PRINCIPAL INVESTIGATOR...SUBTITLE 5a. CONTRACT NUMBER Identification of Prostate Cancer Predisposition Genes on the Y Chromosome 5b. GRANT NUMBER Chromosome 5c. PROGRAM...difficult. We hypothesize the existence of Y chromosome genes/variants related to increased risk, and propose multiple genetic analyses to efficiently

  9. Why genes evolve faster on secondary chromosomes in bacteria.

    Directory of Open Access Journals (Sweden)

    Vaughn S Cooper

    2010-04-01

    Full Text Available In bacterial genomes composed of more than one chromosome, one replicon is typically larger, harbors more essential genes than the others, and is considered primary. The greater variability of secondary chromosomes among related taxa has led to the theory that they serve as an accessory genome for specific niches or conditions. By this rationale, purifying selection should be weaker on genes on secondary chromosomes because of their reduced necessity or usage. To test this hypothesis we selected bacterial genomes composed of multiple chromosomes from two genera, Burkholderia and Vibrio, and quantified the evolutionary rates (dN and dS of all orthologs within each genus. Both evolutionary rate parameters were faster among orthologs found on secondary chromosomes than those on the primary chromosome. Further, in every bacterial genome with multiple chromosomes that we studied, genes on secondary chromosomes exhibited significantly weaker codon usage bias than those on primary chromosomes. Faster evolution and reduced codon bias could in turn result from global effects of chromosome position, as genes on secondary chromosomes experience reduced dosage and expression due to their delayed replication, or selection on specific gene attributes. These alternatives were evaluated using orthologs common to genomes with multiple chromosomes and genomes with single chromosomes. Analysis of these ortholog sets suggested that inherently fast-evolving genes tend to be sorted to secondary chromosomes when they arise; however, prolonged evolution on a secondary chromosome further accelerated substitution rates. In summary, secondary chromosomes in bacteria are evolutionary test beds where genes are weakly preserved and evolve more rapidly, likely because they are used less frequently.

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

    OpenAIRE

    Chih-Ping Chen

    2007-01-01

    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, triploi...

  11. Nuclear links

    International Nuclear Information System (INIS)

    1981-01-01

    The subject is dealt with in sections: introduction; energy and the third world; world energy consumption 1978; oil -the energy dilemma; nuclear chains - introduction; uranium; Namibia; enrichment and reprocessing; countries with enrichment and reprocessing facilities; waste; conclusion; why take the nuclear option; third world countries with nuclear reactors; the arms connection; government spending and human resources 1977 (by countries); nuclear power - the final solution; the fascists; world bank; campaigns; community action in Plogoff; Australian labour movement; NUM against nuclear power; Scottish campaign; students against nuclear energy; anti-nuclear campaign; partizans; 3W1 disarmament and development; campaign ATOM; CANUC; 3W1; SANE. (U.K.)

  12. Sex chromosome complement influences functional callosal myelination.

    Science.gov (United States)

    Moore, S; Patel, R; Hannsun, G; Yang, J; Tiwari-Woodruff, S K

    2013-08-15

    In addition to androgen differences between males and females, there are genetic differences that are caused by unequal dosage of sex chromosome genes. Using the cuprizone-induced demyelination model, we recently showed that surgical gonadectomy of adult mice resulted in decreased normal myelination and remyelination compared to gonadally intact animals, suggesting a supporting role for sex hormones in the maintenance of myelination. However, inherent sex differences in normal myelination and remyelination persisted even after gonadectomy, with males consistently remyelinating to a lesser extent relative to normal myelination as assayed by axon conduction and immunohistochemistry. This suggests a potential role for the sex chromosome complement in mediating the differential rates of remyelination observed in males and females. The present study focuses on the impact that sex chromosomes might have on these myelination differences. Making use of the four core-genotype mice and cuprizone-diet induced demyelination/remyelination paradigm, our results demonstrate sex chromosome-mediated asymmetry between XX and XY mice. The rate of functional remyelination following cuprizone diet-induced callosal demyelination in four core-genotype mice is attenuated in XY compared to XX animals of both gonadal sexes. Importantly, this difference arises only in the absence of circulating sex hormones following gonadectomy and confirms the role of sex hormones in the remyelination process reported earlier by our group. Because a genotype-mediated difference only arises following gonadectomy, the chromosomal contribution to myelination and remyelination is subtle yet significant. To explain this difference, we propose a possible asymmetry in the expression of myelination-related genes in XX vs. XY mice that needs to be investigated in future studies. Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved.

  13. Y-chromosome analysis in Retuertas horses.

    Science.gov (United States)

    Brandariz-Fontes, Claudia; Leonard, Jennifer A; Vega-Pla, José Luis; Backström, Niclas; Lindgren, Gabriella; Lippold, Sebastian; Rico, Ciro

    2013-01-01

    Several studies based on a variety of genetic markers have attempted to establish the origins of horse domestication. Thus far a discrepancy between the results of mitochondrial DNA analysis, which show high levels of diversity, and results from the Y-chromosome, with almost no genetic variability, has been identified. Most previous work on the horse Y-chromosome has focused on widespread, popular breeds or local Asian breeds. It is possible that these breeds represent a reduced set of the genetic variation present in the species. Additional genetic variation may be present in local breeds and ancient feral populations, such as the Retuertas horse in Spain. In this study we analyzed the Y-chromosome of the Retuertas horse, a feral horse population on the Iberian Peninsula that is at least several hundred years old, and whose genetic diversity and morphology suggests that it has been reproductively isolated for a long time. Data from the Retuertas horse was compared to another 11 breeds from the region (Portugal, Spain and France) or likely of Iberian origin, and then to data from 15 more breeds from around the globe. We sequenced 31 introns, Zinc finger Y-chromosomal protein (ZFY) and anonymous Y-linked fragments and genotyped 6 microsatellite loci found on the Y-chromosome. We found no sequence variation among all individuals and all breeds studied. However, fifteen differences were discovered between our data set and reference sequences in GenBank. We show that these likely represent errors within the deposited sequences, and suggest that they should not be used as comparative data for future projects.

  14. Y-chromosome analysis in Retuertas horses.

    Directory of Open Access Journals (Sweden)

    Claudia Brandariz-Fontes

    Full Text Available Several studies based on a variety of genetic markers have attempted to establish the origins of horse domestication. Thus far a discrepancy between the results of mitochondrial DNA analysis, which show high levels of diversity, and results from the Y-chromosome, with almost no genetic variability, has been identified. Most previous work on the horse Y-chromosome has focused on widespread, popular breeds or local Asian breeds. It is possible that these breeds represent a reduced set of the genetic variation present in the species. Additional genetic variation may be present in local breeds and ancient feral populations, such as the Retuertas horse in Spain. In this study we analyzed the Y-chromosome of the Retuertas horse, a feral horse population on the Iberian Peninsula that is at least several hundred years old, and whose genetic diversity and morphology suggests that it has been reproductively isolated for a long time. Data from the Retuertas horse was compared to another 11 breeds from the region (Portugal, Spain and France or likely of Iberian origin, and then to data from 15 more breeds from around the globe. We sequenced 31 introns, Zinc finger Y-chromosomal protein (ZFY and anonymous Y-linked fragments and genotyped 6 microsatellite loci found on the Y-chromosome. We found no sequence variation among all individuals and all breeds studied. However, fifteen differences were discovered between our data set and reference sequences in GenBank. We show that these likely represent errors within the deposited sequences, and suggest that they should not be used as comparative data for future projects.

  15. 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)

  16. 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

  17. Nuclear terrorism

    OpenAIRE

    RUTIC SRDJAN Z.

    2016-01-01

    The paper has analyzed different manifestations of terrorism with nuclear weapons and ionizing radiation as a special kind of terrorism. Possibilities that terrorist groups come into possession of nuclear weapons and apply them for terrorist purposes have been analysed. The forms and methods of terrorist activities with nuclear means have been given as well. It has been concluded that nuclear terrorism includes various forms of threats, including not only nuclear weapons but also the sources ...

  18. Determination of chromosomal ploidy in Agave ssp. | Lingling ...

    African Journals Online (AJOL)

    Chromosome observation is necessary to elucidate the structure, function and organization of Agave plants' genes and genomes. However, few researches about chromosome observation of Agave ssp. were done, not only because their chromosome numbers are large, but also because their ploidies are complicated.

  19. Karyotypic Determinants of Chromosome Instability in Aneuploid Budding Yeast

    Science.gov (United States)

    Bradford, William D.; Li, Rong

    2012-01-01

    Recent studies in cancer cells and budding yeast demonstrated that aneuploidy, the state of having abnormal chromosome numbers, correlates with elevated chromosome instability (CIN), i.e. the propensity of gaining and losing chromosomes at a high frequency. Here we have investigated ploidy- and chromosome-specific determinants underlying aneuploidy-induced CIN by observing karyotype dynamics in fully isogenic aneuploid yeast strains with ploidies between 1N and 2N obtained through a random meiotic process. The aneuploid strains exhibited various levels of whole-chromosome instability (i.e. chromosome gains and losses). CIN correlates with cellular ploidy in an unexpected way: cells with a chromosomal content close to the haploid state are significantly more stable than cells displaying an apparent ploidy between 1.5 and 2N. We propose that the capacity for accurate chromosome segregation by the mitotic system does not scale continuously with an increasing number of chromosomes, but may occur via discrete steps each time a full set of chromosomes is added to the genome. On top of such general ploidy-related effect, CIN is also associated with the presence of specific aneuploid chromosomes as well as dosage imbalance between specific chromosome pairs. Our findings potentially help reconcile the divide between gene-centric versus genome-centric theories in cancer evolution. PMID:22615582

  20. New chromosome numbers in the genus Trigonella L. ( Fabaceae ...

    African Journals Online (AJOL)

    Somatic chromosome numbers of 45 Trigonella L. (Fabaceae), collected from different localities in Turkey was examined. Chromosome numbers were determined as 2n = 14, 16, 30 and 46. B chromosome was also observed in somatic cells of some taxa (Trigonella arcuata C.A. Meyer and Trigonella procumbens (Besser) ...

  1. Dynamic sex chromosomes in Old World chameleons (Squamata: Chamaeleonidae).

    Science.gov (United States)

    Nielsen, S V; Banks, J L; Diaz, R E; Trainor, P A; Gamble, T

    2018-01-18

    Much of our current state of knowledge concerning sex chromosome evolution is based on a handful of 'exceptional' taxa with heteromorphic sex chromosomes. However, classifying the sex chromosome systems of additional species lacking easily identifiable, heteromorphic sex chromosomes is indispensable if we wish to fully understand the genesis, degeneration and turnover of vertebrate sex chromosomes. Squamate reptiles (lizards and snakes) are a potential model clade for studying sex chromosome evolution as they exhibit a suite of sex-determining modes yet most species lack heteromorphic sex chromosomes. Only three (of 203) chameleon species have identified sex chromosome systems (all with female heterogamety, ZZ/ZW). This study uses a recently developed method to identify sex-specific genetic markers from restriction site-associated DNA sequence (RADseq) data, which enables the identification of sex chromosome systems in species lacking heteromorphic sex chromosomes. We used RADseq and subsequent PCR validation to identify an XX/XY sex chromosome system in the veiled chameleon (Chamaeleo calyptratus), revealing a novel transition in sex chromosome systems within the Chamaeleonidae. The sex-specific genetic markers identified here will be essential in research focused on sex-specific, comparative, functional and developmental evolutionary questions, further promoting C. calyptratus' utility as an emerging model organism. © 2018 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2018 European Society For Evolutionary Biology.

  2. Fish on avian lampbrush chromosomes produces higher resolution gene mapping

    NARCIS (Netherlands)

    Galkina, S.A.; Deryusheva, S.; Fillon, V.; Vignal, A.; Crooijmans, R.P.M.A.; Groenen, M.A.M.; Rodionov, A.V.; Gaginskaya, E.

    2006-01-01

    Giant lampbrush chromosomes, which are characteristic of the diplotene stage of prophase I during avian oogenesis, represent a very promising system for precise physical gene mapping. We applied 35 chicken BAC and 4 PAC clones to both mitotic metaphase chromosomes and meiotic lampbrush chromosomes

  3. Chromosomal organization of simple sequence repeats in the ...

    Indian Academy of Sciences (India)

    Chromosome identification is essential in oyster genomic research. Fluorescence in situ hybridization (FISH) offers new opportunities for the identification of oyster chromosomes. It has been used to locate satellite DNAs, telomeres or riboso- mal DNA sequences. However, regarding chromosome identification, no study has ...

  4. Typing of Y chromosome SNPs with multiplex PCR methods

    DEFF Research Database (Denmark)

    Sanchez Sanchez, Juan Jose; Børsting, Claus; Morling, Niels

    2005-01-01

    We describe a method for the simultaneous typing of Y-chromosome single nucleotide polymorphism (SNP) markers by means of multiplex polymerase chain reaction (PCR) strategies that allow the detection of 35 Y chromosome SNPs on 25 amplicons from 100 to 200 pg of chromosomal deoxyribonucleic acid...

  5. 21 CFR 864.2260 - Chromosome culture kit.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Chromosome culture kit. 864.2260 Section 864.2260...) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Cell And Tissue Culture Products § 864.2260 Chromosome culture kit. (a) Identification. A chromosome culture kit is a device containing the necessary ingredients...

  6. The architecture of chicken chromosome territories changes during differentiation

    Directory of Open Access Journals (Sweden)

    Stadler Sonja

    2004-11-01

    Full Text Available Abstract Background Between cell divisions the chromatin fiber of each chromosome is restricted to a subvolume of the interphase cell nucleus called chromosome territory. The internal organization of these chromosome territories is still largely unknown. Results We compared the large-scale chromatin structure of chromosome territories between several hematopoietic chicken cell types at various differentiation stages. Chromosome territories were labeled by fluorescence in situ hybridization in structurally preserved nuclei, recorded by confocal microscopy and evaluated visually and by quantitative image analysis. Chromosome territories in multipotent myeloid precursor cells appeared homogeneously stained and compact. The inactive lysozyme gene as well as the centromere of the lysozyme gene harboring chromosome located to the interior of the chromosome territory. In further differentiated cell types such as myeloblasts, macrophages and erythroblasts chromosome territories appeared increasingly diffuse, disaggregating to separable substructures. The lysozyme gene, which is gradually activated during the differentiation to activated macrophages, as well as the centromere were relocated increasingly to more external positions. Conclusions Our results reveal a cell type specific constitution of chromosome territories. The data suggest that a repositioning of chromosomal loci during differentiation may be a consequence of general changes in chromosome territory morphology, not necessarily related to transcriptional changes.

  7. Chromosome numbers of some indigenous tree species of Ethiopia ...

    African Journals Online (AJOL)

    The present investigation was aimed at carrying out mitotic chromosome studies on some important indigenous tree species of Ethiopia. Somatic chromosome counts were carried out on somatic cells from root tips. In this study, chromosome numbers for the following twelve tree species from ten genera of seven families are ...

  8. 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.

  9. Methods for Cytogenetic Chromosome Barcoding and Chromosome Painting in Brachypodium distachyon and Its Relative Species.

    Science.gov (United States)

    Idziak-Helmcke, Dominika; Betekhtin, Alexander

    2018-01-01

    Brachypodium distachyon provides a particularly appealing object for molecular cytogenetic analysis due to its compact genome and low repetitive DNA content, as well as low (x = 5) basic number of chromosomes easily identifiable on the basis of their morphometric features. Some of these features, such as genome compactness, are shared by the other members of the genus, thus making them amenable for comparative cytogenetic mapping. Cytogenetic infrastructure established for B. distachyon was initially based on fluorescence in situ hybridization with various tandemly repeated sequences as probes. The molecular cytogenetic studies advanced greatly with the development of B. distachyon large DNA insert genomic libraries. These resources coupled with the access to the fully sequenced genome of B. distachyon enabled chromosome painting in monocots for the first time. This pioneering work was subsequently extended to other Brachypodium species, allowing insight into grass karyotype evolution. In this protocol we describe the methods of making somatic and meiotic chromosome preparations, probe labeling, FISH with BAC clones, a strategy for chromosome barcoding and chromosome painting in B. distachyon, and comparative chromosome painting in the other Brachypodium species.

  10. Nuclear safeguards and nuclear shutdowns

    International Nuclear Information System (INIS)

    Worthington, J.D.

    1976-01-01

    The issues involved in the California nuclear initiative (Proposition 15) are described. Some of the characteristics of the anti-nuclear lobby are outlined. Some do's and don'ts for the nuclear group are listed. The nuclear shutdown effort was concentrated on the safeguards and high-level waste disposal issues

  11. Metaphase chromosome analysis by ligation-mediated PCR: heritable chromatin structure and a comparison of active and inactive X chromosomes.

    OpenAIRE

    Hershkovitz, M; Riggs, A D

    1995-01-01

    We report that ligation-mediated PCR (LMPCR) can be used for high-resolution study of metaphase chromosomes, and we discuss the role of metaphase chromatin structure in the preservation of differentiated cell states. The X chromosome-linked human PGK1 (phosphoglycerate kinase 1) promoter region was investigated, and euchromatic active X chromosome (Xa) metaphase chromatin was compared with interphase Xa chromatin and to heterochromatic inactive X chromosome (Xi) metaphase and interphase chrom...

  12. Detection of short repeated genomic sequences on metaphase chromosomes using padlock probes and target primed rolling circle DNA synthesis

    Directory of Open Access Journals (Sweden)

    Stougaard Magnus

    2007-11-01

    Full Text Available Abstract Background In situ detection of short sequence elements in genomic DNA requires short probes with high molecular resolution and powerful specific signal amplification. Padlock probes can differentiate single base variations. Ligated padlock probes can be amplified in situ by rolling circle DNA synthesis and detected by fluorescence microscopy, thus enhancing PRINS type reactions, where localized DNA synthesis reports on the position of hybridization targets, to potentially reveal the binding of single oligonucleotide-size probe molecules. Such a system has been presented for the detection of mitochondrial DNA in fixed cells, whereas attempts to apply rolling circle detection to metaphase chromosomes have previously failed, according to the literature. Methods Synchronized cultured cells were fixed with methanol/acetic acid to prepare chromosome spreads in teflon-coated diagnostic well-slides. Apart from the slide format and the chromosome spreading everything was done essentially according to standard protocols. Hybridization targets were detected in situ with padlock probes, which were ligated and amplified using target primed rolling circle DNA synthesis, and detected by fluorescence labeling. Results An optimized protocol for the spreading of condensed metaphase chromosomes in teflon-coated diagnostic well-slides was developed. Applying this protocol we generated specimens for target primed rolling circle DNA synthesis of padlock probes recognizing a 40 nucleotide sequence in the male specific repetitive satellite I sequence (DYZ1 on the Y-chromosome and a 32 nucleotide sequence in the repetitive kringle IV domain in the apolipoprotein(a gene positioned on the long arm of chromosome 6. These targets were detected with good efficiency, but the efficiency on other target sites was unsatisfactory. Conclusion Our aim was to test the applicability of the method used on mitochondrial DNA to the analysis of nuclear genomes, in particular as

  13. 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

  14. Chromosome behavior at the base of the angiosperm radiation: karyology of Trithuria submersa (Hydatellaceae, Nymphaeales).

    Science.gov (United States)

    Kynast, Ralf G; Joseph, Jeffrey A; Pellicer, Jaume; Ramsay, Margaret M; Rudall, Paula J

    2014-09-01

    • Hydatellaceae are minute annual herbs with potential as a model system for studying early angiosperm evolution, but their karyology and ploidy levels are almost unknown. We investigated these aspects of Trithuria submersa, a widespread species that we show to be amenable to extended vegetative propagation.• We cultivated plants of T. submersa in vitro after developing and optimizing culture conditions. We estimated genome size using flow cytometry, counted chromosome numbers using root-meristem squashes after Feulgen staining, and examined meiotic chromosome behavior using microsporocytes.• We developed methods to reliably germinate seeds of T. submersa and to propagate them vegetatively in critical thermo- and photoperiod regimes on 1/2 Murashige-Skoog (MS) medium with vitamins and 2% sucrose solidified with 0.7% agar-agar. Seedling growth requires the medium be supplemented with activated charcoal. The mean nuclear DNA content of T. submersa sporophytes is 2C = 2.74 pg (∼2.68 Gbp). The sporophytic chromosome number is 2n = 56 with a bimodal complement, which may suggest an allopolyploid origin. Some of the largest chromosomes lack a recognizable constriction, which relates to a highly unusual and irregular chromosome behavior. Microsporocytes undergo reduced and asynchronous meioses that show a modified intermediate cell division with a nucleus division by fractional postreduction, indicating partially inverted microsporogenesis.• In vitro cultivation and karyological assessment of T. submersa open new opportunities for investigating early-divergent angiosperms. The remarkably different meiotic behavior exhibits new insights into a potentially ancestral microsporogenesis. © 2014 Botanical Society of America, Inc.

  15. Chromosomal Translocations: Chicken or Egg? | Center for Cancer Research

    Science.gov (United States)

    Many tumor cells have abnormal chromosomes. Some of these abnormalities are caused by chromosomal translocations, which occur when two chromosomes break and incorrectly rejoin, resulting in an exchange of genetic material. Translocations can activate oncogenes, silence tumor suppressor genes, or result in the creation of completely new fusion gene products. While there is little doubt that chromosomal translocations can contribute to cancer, there is an active "chicken and the egg" discussion about the role translocations and other chromosomal abnormalities play—do they actually cause cancer or merely occur because of other changes within the cancer cell.  

  16. Dynamic chromosome reorganization in the osprey ( Pandion haliaetus , Pandionidae, Falconiformes): relationship between chromosome size and the chromosomal distribution of centromeric repetitive DNA sequences.

    Science.gov (United States)

    Nishida, C; Ishishita, S; Yamada, K; Griffin, D K; Matsuda, Y

    2014-01-01

    The osprey (Pandion haliaetus) has a diploid number of 74 chromosomes, consisting of a large number of medium-sized macrochromosomes and relatively few microchromosomes; this differs greatly from the typical avian karyotype. Chromosome painting with chicken DNA probes revealed that the karyotype of P. haliaetus differs from the chicken karyotype by at least 14 fission events involving macrochromosomes (chicken chromosomes 1-9 and Z) and at most 15 fusions of microchromosomes, suggesting that considerable karyotype reorganization occurred in P. haliaetus in a similar manner previously reported for Accipitridae. A distinct difference was observed, however, between Accipitridae and Pandionidae with respect to the pattern of chromosome rearrangements that occurred after fissions of macrochromosomes. Metacentric or submetacentric chromosomes 1-5 in P. haliaetus appear to have been formed by centric fusion of chromosome segments derived from macrochromosomal fissions. By contrast, many pairs of bi-armed chromosomes in Accipitridae species seem to result from pericentric inversions that occurred in the fission-derived chromosomes. Two families of repetitive sequences were isolated; the 173-bp PHA-HaeIII sequence occurred on all chromosomes, whereas intense signals from the 742-bp PHA-NsiI sequence were localized to all acrocentric chromosomes, with weak signals on most of the bi-armed chromosomes. Two repetitive sequences cohybridized in the centromeric heterochromatin; however, the sequences differed in unit size, nucleotide sequence and GC content. The results suggest that the 2 sequence families originated from different ancestral sequences and were homogenized independently in centromeres, and that a chromosome size-dependent compartmentalization may have been lost in P. haliaetus. © 2014 S. Karger AG, Basel.

  17. The chromosomal constitution of wine strains of Saccharomyces cerevisiae.

    Science.gov (United States)

    Bakalinsky, A T; Snow, R

    1990-01-01

    A general procedure is described for determining the chromosomal constitution of industrial strains of Saccharomyces cerevisiae based on analysis of segregation frequencies for input markers among random spore progeny of industrial-laboratory strain hybrids. The multiply auxotrophic haploid testers used carried a dominant erythromycin-resistance marker, allowing hybrids to be selected in mass matings with spores produced by the wild-type industrial strains. Analysis of a number of independent crosses between the haploid testers and an unselected population of spores of each wine strain distinguished between disomic, trisomic and tetrasomic chromosomal complements in the parents. Possible explanations for a significant class of aberrant segregation frequencies are discussed. Results of the analysis indicate that UCD Enology 522 (Montrachet) is diploid and possibly trisomic for chromosome VII; 522X is diploid; UCD Enology 505 (California Champagne) is disomic for chromosome XVI, trisomic for chromosomes I, II, III, VI, VIII, IX, X, XII, XV, tetrasomic for chromosomes IV, XI, XIII, XIV and either trisomic or tetrasomic for chromosomes V and VII; and that UCD Enology 595 (Pasteur Champagne) is disomic for chromosomes I, II, III, IX, XVI, trisomic for chromosomes IV, VI, X, XII, XIV, XV, tetrasomic for chromosomes V, VIII, XI, XIII and either disomic or tetrasomic for chromosome VII.

  18. Modeling Three-Dimensional Chromosome Structures Using Gene Expression Data.

    Science.gov (United States)

    Xiao, Guanghua; Wang, Xinlei; Khodursky, Arkady B

    2011-03-01

    Recent genomic studies have shown that significant chromosomal spatial correlation exists in gene expression of many organisms. Interestingly, coexpression has been observed among genes separated by a fixed interval in specific regions of a chromosome chain, which is likely caused by three-dimensional (3D) chromosome folding structures. Modeling such spatial correlation explicitly may lead to essential understandings of 3D chromosome structures and their roles in transcriptional regulation. In this paper, we explore chromosomal spatial correlation induced by 3D chromosome structures, and propose a hierarchical Bayesian method based on helical structures to formally model and incorporate the correlation into the analysis of gene expression microarray data. It is the first study to quantify and infer 3D chromosome structures in vivo using expression microarrays. Simulation studies show computing feasibility of the proposed method and that, under the assumption of helical chromosome structures, it can lead to precise estimation of structural parameters and gene expression levels. Real data applications demonstrate an intriguing biological phenomenon that functionally associated genes, which are far apart along the chromosome chain, are brought into physical proximity by chromosomal folding in 3D space to facilitate their coexpression. It leads to important biological insight into relationship between chromosome structure and function.

  19. Defining the anatomy of the Rangifer tarandus sex chromosomes.

    Science.gov (United States)

    Lee, C; Griffin, D K; O'Brien, P C; Yang, F; Lin, C C; Ferguson-Smith, M A

    1998-03-01

    A comprehensive cytogenetic characterization of the unusally large reindeer (Rangifer tarandus) sex chromosomes is presented for the purpose of studying the evolution of these atypical gonosomes. Sex chromosome idiograms were constructed from G-banded and C-banded chromosomes to illustrate the relative amounts and locations of euchromatin and heterochromatin. Hybridization with a Mazama gouazoubira X whole-chromosome paint revealed that essentially all reindeer X-linked euchromatin and most reindeer Y-linked euchromatin is conserved interspecifically. Subsequently, painting probes were generated from flow-sorted reindeer X chromosomes, flow-sorted reindeer Y chromosomes, and from microdissections of specific gonosomal regions to establish specific segment-to-segment homologies between these gonosomes. In particular, one microdissection-generated paint demonstrated that certain constituent repetitive DNAs, found in C-band region Xq31, were also present in essentially all heterochromatin blocks of the Y chromosome. Microdissection-generated paints from other X-linked heterochromatin blocks revealed the presence of DNA sequences that lacked homologous sequences on the Y chromosomes and were more specific for their region of origin. These characteristics of the reindeer sex chromosomes are consistent with the notion that mammalian sex chromosomes were derived from homologous progenitor chromosome pairs and provide insights into the evolution of these atypical mammalian gonosomes.

  20. X Chromosome and Autosome Dosage Responses in Drosophila melanogaster Heads

    Science.gov (United States)

    Chen, Zhen-Xia; Oliver, Brian

    2015-01-01

    X chromosome dosage compensation is required for male viability in Drosophila. Dosage compensation relative to autosomes is two-fold, but this is likely to be due to a combination of homeostatic gene-by-gene regulation and chromosome-wide regulation. We have baseline values for gene-by-gene dosage compensation on autosomes, but not for the X chromosome. Given the evolutionary history of sex chromosomes, these baseline values could differ. We used a series of deficiencies on the X and autosomes, along with mutations in the sex-determination gene transformer-2, to carefully measure the sex-independent X-chromosome response to gene dosage in adult heads by RNA sequencing. We observed modest and indistinguishable dosage compensation for both X chromosome and autosome genes, suggesting that the X chromosome is neither inherently more robust nor sensitive to dosage change. PMID:25850426

  1. Chromosomal anomalies in infertile azoospermic and oligospermic men

    Directory of Open Access Journals (Sweden)

    Kalantari P

    2001-08-01

    Full Text Available In this study, chromosome analyses were performed on 70 infertile Azoospermic and Oligospermic (<20 million/ml men, and also cultures of peripheral blood lymphocytes by high resolution banding method were analysed as well. It is revealed 8 (11.43 percent men with chromosomal abnormality. There were 31.4 percent patients with azoospermia and 68.6 percent with oligospermia from several thousands to 20×10^6 million/ml and their duration of infertility was at least 2 years. All patients with numerical chromosome anomalies had azoospermia and the most frequent anomaly was 47, XXY chromosomal constitution (klinfelter's syndrome, found in 8.57 percent of patients. We found that chromosomal anomalies found in this study were sex chromosome anomalies and an increased rate of numerical chromosomal abnormalities was among men with azoospermia. As a conclusion, we suggest that all men with azoospermia be considered for cytogenetical evaluation. 

  2. Chromosome heteromorphisms in the Japanese, 1

    International Nuclear Information System (INIS)

    Sofuni, Toshio; Tanabe, Kazumi; Awa, A.A.

    1979-02-01

    Thirty-four cases with Dp+ and Gp+, known to be chromosome heteromorphisms in man, were examined using Q- and C-staining methods. Of 18 cases with Dp+, 14 involved No. 15 chromosome and 2 each were No. 13 and No. 14 respectively. Of 16 cases with Gp+, 13 were concerned with No. 22 and the remaining 3 were No. 21. Short arm regions of eight cases with 15p+ and one with 14p+ were stained very darkly by the C-method, but did not fluoresce brilliantly by the Q-method. On the other hand, brightly fluorescing short arm regions observed in three cases with 15p+ and two with 22p+, were not very darkly stained by the C-method. In the remaining 20 cases, short arm regions were not stained positively by either method, but showed negatively or intermediately variable staining intensities. (author)

  3. Diagnosis of Fanconi Anemia: Chromosomal Breakage Analysis

    Directory of Open Access Journals (Sweden)

    Anneke B. Oostra

    2012-01-01

    Full Text Available Fanconi anemia (FA is a rare inherited syndrome with diverse clinical symptoms including developmental defects, short stature, bone marrow failure, and a high risk of malignancies. Fifteen genetic subtypes have been distinguished so far. The mode of inheritance for all subtypes is autosomal recessive, except for FA-B, which is X-linked. Cells derived from FA patients are—by definition—hypersensitive to DNA cross-linking agents, such as mitomycin C, diepoxybutane, or cisplatinum, which becomes manifest as excessive growth inhibition, cell cycle arrest, and chromosomal breakage upon cellular exposure to these drugs. Here we provide a detailed laboratory protocol for the accurate assessment of the FA diagnosis as based on mitomycin C-induced chromosomal breakage analysis in whole-blood cultures. The method also enables a quantitative estimate of the degree of mosaicism in the lymphocyte compartment of the patient.

  4. Diagnosis of Fanconi Anemia: Chromosomal Breakage Analysis

    Science.gov (United States)

    Oostra, Anneke B.; Nieuwint, Aggie W. M.; Joenje, Hans; de Winter, Johan P.

    2012-01-01

    Fanconi anemia (FA) is a rare inherited syndrome with diverse clinical symptoms including developmental defects, short stature, bone marrow failure, and a high risk of malignancies. Fifteen genetic subtypes have been distinguished so far. The mode of inheritance for all subtypes is autosomal recessive, except for FA-B, which is X-linked. Cells derived from FA patients are—by definition—hypersensitive to DNA cross-linking agents, such as mitomycin C, diepoxybutane, or cisplatinum, which becomes manifest as excessive growth inhibition, cell cycle arrest, and chromosomal breakage upon cellular exposure to these drugs. Here we provide a detailed laboratory protocol for the accurate assessment of the FA diagnosis as based on mitomycin C-induced chromosomal breakage analysis in whole-blood cultures. The method also enables a quantitative estimate of the degree of mosaicism in the lymphocyte compartment of the patient. PMID:22693659

  5. Bacterial Artificial Chromosome Mutagenesis Using Recombineering

    Directory of Open Access Journals (Sweden)

    Kumaran Narayanan

    2011-01-01

    Full Text Available Gene expression from bacterial artificial chromosome (BAC clones has been demonstrated to facilitate physiologically relevant levels compared to viral and nonviral cDNA vectors. BACs are large enough to transfer intact genes in their native chromosomal setting together with flanking regulatory elements to provide all the signals for correct spatiotemporal gene expression. Until recently, the use of BACs for functional studies has been limited because their large size has inherently presented a major obstacle for introducing modifications using conventional genetic engineering strategies. The development of in vivo homologous recombination strategies based on recombineering in E. coli has helped resolve this problem by enabling facile engineering of high molecular weight BAC DNA without dependence on suitably placed restriction enzymes or cloning steps. These techniques have considerably expanded the possibilities for studying functional genetics using BACs in vitro and in vivo.

  6. Chromosome analysis using spectral karyotyping (SKY).

    Science.gov (United States)

    Imataka, George; Arisaka, Osamu

    2012-01-01

    Spectral karyotyping is a novel technique for chromosome analysis that has been developed based on the approach of the fluorescence in situ hybridization technique. Spectral karyotyping makes it feasible to diagnose a variety of diseases, because of its technology in painting each of the 24 human chromosomes with different colors. In recent years, it has become possible to adopt the usage of spectral karyotyping for research in general clinical practice, and its usability has attracted particular attention in the diagnosis of different diseases. In this review, we will explain the principle of the spectral karyotyping, as well as its specificity and limitation in detecting the genetic defects within clinical application by presenting two case reports.

  7. Chromosome-based genomics in cereals

    Czech Academy of Sciences Publication Activity Database

    Doležel, Jaroslav; Kubaláková, Marie; Paux, E.; Bartoš, Jan; Feuillet, C.

    2007-01-01

    Roč. 15, č. 1 (2007), s. 51-66 ISSN 0967-3849 R&D Projects: GA ČR GP521/06/P412; GA ČR(CZ) GA521/05/0257; GA ČR GA521/06/1723; GA MŠk ME 884; GA MŠk(CZ) LC06004 Institutional research plan: CEZ:AV0Z50380511 Source of funding: V - iné verejné zdroje ; V - iné verejné zdroje ; V - iné verejné zdroje ; V - iné verejné zdroje ; V - iné verejné zdroje Keywords : Chromosome sorting * chromosome-specific BAC libraries * flow cytometry Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.469, year: 2007

  8. American marsupials chromosomes: why study them?

    Directory of Open Access Journals (Sweden)

    Marta Svartman

    Full Text Available Marsupials, one of the three main groups of mammals, are only found in Australia and in the American continent. Studies performed in Australian marsupials have demonstrated the great potential provided by the group for the understanding of basic genetic mechanisms and chromosome evolution in mammals. Genetic studies in American marsupials are relatively scarce and cytogenetic data of most species are restricted to karyotype descriptions, usually without banding patterns. Nevertheless, the first marsupial genome sequenced was that of Monodelphis domestica, a South American species. The knowledge about mammalian genome evolution and function that resulted from studies on M. domestica is in sharp contrast with the lack of genetic data on most American marsupial species. Here, we present an overview of the chromosome studies performed in marsupials with emphasis on the South American species.

  9. Antibodies against chromosomal beta-lactamase

    DEFF Research Database (Denmark)

    Giwercman, B; Rasmussen, J W; Ciofu, Oana

    1994-01-01

    A murine monoclonal anti-chromosomal beta-lactamase antibody was developed and an immunoblotting technique was used to study the presence of serum and sputum antibodies against Pseudomonas aeruginosa chromosomal group 1 beta-lactamase in patients with cystic fibrosis (CF). The serum antibody...... response was studied with serum samples collected in 1992 from 56 CF patients in a cross-sectional study and with serum samples from 18 CF patients in a longitudinal study. Anti-beta-lactamase immunoglobulin G antibodies were present in all of the serum samples from the patients with chronic...... bronchopulmonary P. aeruginosa infection (CF + P) but in none of the CF patients with no or intermittent P. aeruginosa infection. Anti-beta-lactamase antibodies were present in serum from CF + P patients after six antipseudomonal courses (median) and correlated with infection with a beta-lactam-resistant strain...

  10. Bias of purine stretches in sequenced chromosomes

    DEFF Research Database (Denmark)

    Ussery, David; Soumpasis, Dikeos Mario; Brunak, Søren

    2002-01-01

    We examined more than 700 DNA sequences (full length chromosomes and plasmids) for stretches of purines (R) or pyrimidines (Y) and alternating YR stretches; such regions will likely adopt structures which are different from the canonical B-form. Since one turn of the DNA helix is roughly 10 bp, we...... measured the fraction of each genome which contains purine (or pyrimidine) tracts of lengths of 10 by or longer (hereafter referred to as 'purine tracts'), as well as stretches of alternating pyrimidines/purine ('pyr/pur tracts') of the same length. Using this criteria, a random sequence would be expected...... to contain 1.0% of purine tracts and also 1.0% of the alternating pyr/pur tracts. In the vast majority of cases, there are more purine tracts than would be expected from a random sequence, with an average of 3.5%, significantly larger than the expectation value. The fraction of the chromosomes containing pyr...

  11. Chromosomes of American species of Sida (Malvaceae

    Directory of Open Access Journals (Sweden)

    Graciela I. Lavia

    2007-09-01

    Full Text Available Chromosome numbers are reported for 26 accessions of Sida (Malvaceae from Argentina, Bolivia, Brazil, México and Paraguay representing 15 species. First chromosome counts are cited for the following 8 species: S. Charpinii Krapov. 2n=14, S. ciliaris L. 2n=16, S. Monteiroi Krapov. 2n=16, S. anomala A. St.-Hil. 2n=16,S. Cristobaliana Krapov. 2n=32, S. dubia A. St.-Hil. & Naudin 2n=14, S. Poeppigiana (K.Schum. Fryxell 2n=14 and S. Leitaofilhoi Krapov. 2n=14.

  12. Chromosome analyses of nurses handling cytostatic agents

    International Nuclear Information System (INIS)

    Waksvik, H.; Klepp, O.; Brogger, A.

    1981-01-01

    A cytogenetic study of ten nurses handling cytostatic agents (average exposure, 2150 hours) and ten female hospital clerks revealed an increased frequency of chromosome gaps and a slight increase in sister chromatid exchange frequency among the nurses. The increase may be due to exposure to cytostatic drugs and points to these agents as a possible occupational health hazard. A second group of 11 nurses handling cytostatic agents for a shorter period of time (average exposure, 1078 hours), and three other groups (eight nurses engaged in therapeutic and diagnostic radiology, nine nurses engaged in anesthesiology, and seven nurses in postoperative ward) did not differ from the office personnel, except for an increased frequency of chromosome gaps in the radiology group

  13. American marsupials chromosomes: why study them?

    Directory of Open Access Journals (Sweden)

    Marta Svartman

    2009-01-01

    Full Text Available Marsupials, one of the three main groups of mammals, are only found in Australia and in the American continent. Studies performed in Australian marsupials have demonstrated the great potential provided by the group for the understanding of basic genetic mechanisms and chromosome evolution in mammals. Genetic studies in American marsupials are relatively scarce and cytogenetic data of most species are restricted to karyotype descriptions, usually without banding patterns. Nevertheless, the first marsupial genome sequenced was that of Monodelphis domestica, a South American species. The knowledge about mammalian genome evolution and function that resulted from studies on M. domestica is in sharp contrast with the lack of genetic data on most American marsupial species. Here, we present an overview of the chromosome studies performed in marsupials with emphasis on the South American species.

  14. Dense chromatin plates in metaphase chromosomes.

    Science.gov (United States)

    Gállego, Isaac; Castro-Hartmann, Pablo; Caravaca, Juan Manuel; Caño, Silvia; Daban, Joan-Ramon

    2009-04-01

    In a previous work we observed multilayered plate-like structures surrounding partially denatured HeLa chromosomes at metaphase ionic conditions. This unexpected finding has led us to carry out an extensive investigation of these structures. Our results show that plates can also be found in metaphase chromosomes from chicken lymphocytes. We have used atomic force microscopy (AFM) to image and investigate the mechanical properties of plates in aqueous solution. Plates are thin (approximately 6.5 nm each layer) but compact and resistant to penetration by the AFM tip: their Young's modulus is approximately 0.2 GPa and the stress required for surface penetration is approximately 0.03 GPa in the presence of Mg(2+) (5-20 mM). Low-ionic strength conditions produce emanation of chromatin fibers from the edges of uncrosslinked plates. These observations and AFM results obtained applying high forces indicate that the chromatin filament is tightly tethered inside the plates. Images of metal-shadowed plates and cryo-electron microscopy images of frozen-hydrated plates suggest that nucleosomes are tilted with respect to the plate surface to allow an interdigitation between the successive layers and a thickness reduction compatible with the observed plate height. The similarities between denatured plates from chicken chromosomes and aggregates of purified chromatin from chicken erythrocytes suggest that chromatin has intrinsic structural properties leading to plate formation. Scanning electron micrographs and images obtained with the 200-kV transmission microscope show that plates are the dominant component of compact chromatids. We propose that metaphase chromosomes are formed by many stacked plates perpendicular to the chromatid axis.

  15. Analysis and visualization of chromosome information.

    Science.gov (United States)

    Machado, J A Tenreiro; Costa, António C; Quelhas, Maria Dulce

    2012-01-01

    This paper analyzes the DNA code of several species in the perspective of information content. For that purpose several concepts and mathematical tools are selected towards establishing a quantitative method without a priori distorting the alphabet represented by the sequence of DNA bases. The synergies of associating Gray code, histogram characterization and multidimensional scaling visualization lead to a collection of plots with a categorical representation of species and chromosomes. Copyright © 2011 Elsevier B.V. All rights reserved.

  16. Difficult cases for chromosomal dosimetry: Statistical considerations

    Energy Technology Data Exchange (ETDEWEB)

    Vinnikov, Volodymyr A., E-mail: vlad.vinnikov@mail.ru [Grigoriev Institute for Medical Radiology of the National Academy of Medical Science of Ukraine, Pushkinskaya Street 82, Kharkiv 61024 (Ukraine); Ainsbury, Elizabeth A., E-mail: liz.ainsbury@hpa.org.uk [Health Protection Agency, Centre for Radiation, Chemical and Environmental Hazards, Chilton, Didcot, Oxon OX11 0RQ (United Kingdom); Lloyd, David C., E-mail: david.lloyd@hpa.org.uk [Health Protection Agency, Centre for Radiation, Chemical and Environmental Hazards, Chilton, Didcot, Oxon OX11 0RQ (United Kingdom); Maznyk, Nataliya A., E-mail: maznik.cytogen@mail.ru [Grigoriev Institute for Medical Radiology of the National Academy of Medical Science of Ukraine, Pushkinskaya Street 82, Kharkiv 61024 (Ukraine); Rothkamm, Kai, E-mail: kai.rothkamm@hpa.org.uk [Health Protection Agency, Centre for Radiation, Chemical and Environmental Hazards, Chilton, Didcot, Oxon OX11 0RQ (United Kingdom)

    2011-09-15

    Several examples are selected from the literature in order to illustrate combinations of complicating factors, which may occur in real-life radiation exposure scenarios that affect the accuracy of cytogenetic dose estimates. An analysis of limitations in the current statistical methods used in biodosimetry was carried out. Possible directions for further improvement of the statistical basis of chromosomal dosimetry by specific mathematical procedures are outlined.

  17. Y-chromosome STR haplotypes in Danes

    DEFF Research Database (Denmark)

    Hallenberg, Charlotte; Nielsen, Karsten; Simonsen, Bo Thisted

    2005-01-01

    A total of 185 unrelated Danish males were typed for the Y-chromosome STRs DYS19, DYS385a/b, DYS389-I, DYS389-II, DYS390, DYS391, DYS392, DYS393, DYS437, DYS438 and DYS439 using the kits PowerPlex Y (Promega), ReliaGene Y-Plex 6 and ReliaGene Y-Plex 5 (Reliagene Technologies). A total of 163...

  18. Evolution of sex chromosomes in Sauropsida

    OpenAIRE

    Organ, Christopher L.; Janes, Daniel E.

    2008-01-01

    Reptiles (sauropsids) represent the sister group to mammals, and the basal members of Reptilia may provide a good model for the condition of the common ancestor of both groups. Sex-determining mechanisms (SDM) and organizations of sex chromosomes among genotypically sex-determining (GSD) species vary widely across reptiles. Birds and snakes, for example, are entirely GSD whereas other reptiles, like all crocodilians, exhibit temperature-dependent sex determination (TSD). Here we explore the e...

  19. Mosaicism for a chromosome 8-derived minute marker chromosome in a patient with manifestations of trisomy 8 mosaicism

    Energy Technology Data Exchange (ETDEWEB)

    Spinner, N.B.; Grace, K.R.; Owens, N.L. [Children`s Hospital of Philadelphia, PA (United States)] [and others

    1995-03-13

    We describe a patient with manifestations of the mosaic trisomy 8 syndrome and mosaicism for a minute marker chromosome. Fluorescence in situ hybridization (FISH) with a chromosome 8 probe confirmed that the marker was derived from chromosome 8. This is the smallest piece of chromosome 8 to be reported in a patient with mosaic trisomy 8 syndrome. When the clinical picture is strongly suggestive of trisomy for a specific chromosome region, we believe that FISH can be used to test markers in a guided, rather than random, fashion. 8 refs., 3 figs.

  20. JPRS Report, Nuclear Developments

    National Research Council Canada - National Science Library

    1989-01-01

    Partial Contents: Nuclear Weapons, Nuclear Development, Nuclear Power Plant, Uranium, Missiles, Space Firm Protested, Satellite, Rocket Launching, Nuclear Submarine, Environmental, Radioactivity, Nuclear Plant...

  1. Chromosome length scaling in haploid, asexual reproduction

    International Nuclear Information System (INIS)

    Oliveira, P M C de

    2007-01-01

    We study the genetic behaviour of a population formed by haploid individuals which reproduce asexually. The genetic information for each individual is stored along a bit-string (or chromosome) with L bits, where 0-bits represent the wild allele and 1-bits correspond to harmful mutations. Each newborn inherits this chromosome from its parent with a few random mutations: on average a fixed number m of bits are flipped. Selection is implemented according to the number N of 1-bits counted along the individual's chromosome: the smaller N the higher the probability an individual has to survive a new time step. Such a population evolves, with births and deaths, and its genetic distribution becomes stabilized after sufficiently many generations have passed. The question we pose concerns the procedure of increasing L. The aim is to get the same distribution of genetic loads N/L among the equilibrated population, in spite of a larger L. Should we keep the same mutation rate m/L for different values of L? The answer is yes, which intuitively seems to be plausible. However, this conclusion is not trivial, according to our simulation results: the question also involves the population size

  2. The variability is in the sex chromosomes.

    Science.gov (United States)

    Reinhold, Klaus; Engqvist, Leif

    2013-12-01

    Sex differences in the mean trait expression are well documented, not only for traits that are directly associated with reproduction. Less is known about how the variability of traits differs between males and females. In species with sex chromosomes and dosage compensation, the heterogametic sex is expected to show larger trait variability ("sex-chromosome hypothesis"), yet this central prediction, based on fundamental genetic principles, has never been evaluated in detail. Here we show that in species with heterogametic males, male variability in body size is significantly larger than in females, whereas the opposite can be shown for species with heterogametic females. These results support the prediction of the sex-chromosome hypothesis that individuals of the heterogametic sex should be more variable. We argue that the pattern demonstrated here for sex-specific body size variability is likely to apply to any trait and needs to be considered when testing predictions about sex-specific variability and sexual selection. © 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.

  3. Artificial chromosomes for antibiotic-producing actinomycetes.

    Science.gov (United States)

    Sosio, M; Giusino, F; Cappellano, C; Bossi, E; Puglia, A M; Donadio, S

    2000-03-01

    Bacteria belonging to the order Actinomycetales produce most microbial metabolites thus far described, several of which have found applications in medicine and agriculture. However, most strains were discovered by their ability to produce a given molecule and are, therefore, poorly characterized physiologically and genetically. Thus, methodologies for genetic manipulation of actinomycetes are not available and efficient tools have been developed for just a few strains. This constitutes a serious limitation to applying molecular genetics approaches to strain development and structural manipulation of microbial metabolites. To overcome this hurdle, we have developed bacterial artificial chromosomes (BAC) that can be shuttled among Escherichia coli, where they replicate autonomously, and a suitable Streptomyces host, where they integrate site-specifically into the chromosome. The existence of gene clusters and of genetically amenable host strains, such as Streptomyces coelicolor or Streptomyces lividans, makes this a sensible approach. We report here that 100 kb segments of actinomycete DNA can be cloned into these vectors and introduced into genetically accessible S. lividans, where they are stably maintained in integrated form in its chromosome.

  4. Chromosome length scaling in haploid, asexual reproduction

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, P M C de [Instituto de Fisica, Universidade Federal Fluminense, avenida Litoranea s/n, Boa Viagem, Niteroi 24210-340 (Brazil)

    2007-02-14

    We study the genetic behaviour of a population formed by haploid individuals which reproduce asexually. The genetic information for each individual is stored along a bit-string (or chromosome) with L bits, where 0-bits represent the wild allele and 1-bits correspond to harmful mutations. Each newborn inherits this chromosome from its parent with a few random mutations: on average a fixed number m of bits are flipped. Selection is implemented according to the number N of 1-bits counted along the individual's chromosome: the smaller N the higher the probability an individual has to survive a new time step. Such a population evolves, with births and deaths, and its genetic distribution becomes stabilized after sufficiently many generations have passed. The question we pose concerns the procedure of increasing L. The aim is to get the same distribution of genetic loads N/L among the equilibrated population, in spite of a larger L. Should we keep the same mutation rate m/L for different values of L? The answer is yes, which intuitively seems to be plausible. However, this conclusion is not trivial, according to our simulation results: the question also involves the population size.

  5. Meiotic transmission of Drosophila pseudoobscura chromosomal arrangements.

    Directory of Open Access Journals (Sweden)

    Richard P Meisel

    Full Text Available Drosophila pseudoobscura harbors a rich gene arrangement polymorphism on the third chromosome generated by a series of overlapping paracentric inversions. The arrangements suppress recombination in heterokaryotypic individuals, which allows for the selective maintenance of coadapted gene complexes. Previous mapping experiments used to determine the degree to which recombination is suppressed in gene arrangement heterozygotes produced non-recombinant progeny in non-Mendelian ratios. The deviations from Mendelian expectations could be the result of viability differences between wild and mutant chromosomes, meiotic drive because of achiasmate pairing of homologues in heterokaryotypic females during meiosis, or a combination of both mechanisms. The possibility that the frequencies of the chromosomal arrangements in natural populations are affected by mechanisms other than adaptive selection led us to consider these hypotheses. We performed reciprocal crosses involving both heterozygous males and females to determine if the frequency of the non-recombinant progeny deviates significantly from Mendelian expectations and if the frequencies deviate between reciprocal crosses. We failed to observe non-Mendelian ratios in multiple crosses, and the frequency of the non-recombinant classes differed in only one of five pairs of reciprocal crosses despite sufficient power to detect these differences in all crosses. Our results indicate that deviations from Mendelian expectations in recombination experiments involving the D. pseudoobscura inversion system are most likely due to fitness differences of gene arrangement karyotypes in different environments.

  6. Nuclear forensics

    International Nuclear Information System (INIS)

    Venugopal, V.

    2010-01-01

    Nuclear forensics is the analysis of nuclear materials recovered from either the capture of unused materials, or from the radioactive debris following a nuclear explosion and can contribute significantly to the identification of the sources of the materials and the industrial processes used to obtain them. In the case of an explosion, nuclear forensics can also reconstruct key features of the nuclear device. Nuclear forensic analysis works best in conjunction with other law enforcement, radiological protection dosimetry, traditional forensics, and intelligence work to provide the basis for attributing the materials and/or nuclear device to its originators. Nuclear forensics is a piece of the overall attribution process, not a stand-alone activity

  7. Nuclear Scans

    Science.gov (United States)

    Nuclear scans use radioactive substances to see structures and functions inside your body. They use a special ... images. Most scans take 20 to 45 minutes. Nuclear scans can help doctors diagnose many conditions, including ...

  8. Chromosomal rearrangements and karyotype evolution in carnivores revealed by chromosome painting

    Science.gov (United States)

    Nie, W; Wang, J; Su, W; Wang, D; Tanomtong, A; Perelman, P L; Graphodatsky, A S; Yang, F

    2012-01-01

    Chromosomal evolution in carnivores has been revisited extensively using cross-species chromosome painting. Painting probes derived from flow-sorted chromosomes of the domestic dog, which has one of the most rearranged karyotypes in mammals and the highest dipoid number (2n=78) in carnivores, are a powerful tool in detecting both evolutionary intra- and inter-chromosomal rearrangements. However, only a few comparative maps have been established between dog and other non-Canidae species. Here, we extended cross-species painting with dog probes to seven more species representing six carnivore families: Eurasian lynx (Lynx lynx), the stone marten (Martes foina), the small Indian civet (Viverricula indica), the Asian palm civet (Paradoxurus hermaphrodites), Javan mongoose (Hepestes javanicas), the raccoon (Procyon lotor) and the giant panda (Ailuropoda melanoleuca). The numbers and positions of intra-chromosomal rearrangements were found to differ among these carnivore species. A comparative map between human and stone marten, and a map among the Yangtze finless porpoise (Neophocaena phocaenoides asiaeorientalis), stone marten and human were also established to facilitate outgroup comparison and to integrate comparative maps between stone marten and other carnivores with such maps between human and other species. These comparative maps give further insight into genome evolution and karyotype phylogenetic relationships among carnivores, and will facilitate the transfer of gene mapping data from human, domestic dog and cat to other species. PMID:22086079

  9. Mapping of the ARIX homeodomain gene to mouse chromosome 7 and human chromosome 11q13

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, K.R. [Jackson Lab., Bar Harbor, ME (United States); Smith, L.; Rhodes, J. [Oregon Health Sciences Univ., Portland, OR (United States)] [and others

    1996-05-01

    The recently described homeodomain protein ARIX is expressed specifically in noradreneric cell types of the sympathetic nervous system, brain, and adrenal medulla. ARIX interacts with regulatory elements of the genes encoding the noradrenergic biosynthetic enzymes tyrosine hydroxylase and dopamine {beta}-hydroxylase, suggesting a role for ARIX in expression of the noradrenergic phenotype. In the study described here, the mouse and human ARIX genes are mapped. Using segregation analysis of two panels of mouse backcross DNA, mouse Arix was positioned approximately 50 cM distal to the centromere of chromosome 7, near Hbb. Human ARIX was positioned through analysis of somatic cell hybrids and fluorescence in situ hybridization of human metaphase chromosomes to chromosome 7, near Hbb. Human ARIX was positioned through analysis of somatic cell hybrids and fluorescence in situ hybridization of human metaphase chromosomes to chromosome 11q13.3-q13.4. These map locations extend and further define regions of conserved synteny between mouse and human genomes and identify a new candidate gene for inherited developmental disorders linked to human 11q13.

  10. 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

  11. Chromosomal phylogeny of Vampyressine bats (Chiroptera, Phyllostomidae) with description of two new sex chromosome systems.

    Science.gov (United States)

    Gomes, Anderson José Baia; Nagamachi, Cleusa Yoshiko; Rodrigues, Luis Reginaldo Ribeiro; Benathar, Thayse Cristine Melo; Ribas, Talita Fernanda Augusto; O'Brien, Patricia Caroline Mary; Yang, Fengtang; Ferguson-Smith, Malcolm Andrew; Pieczarka, Julio Cesar

    2016-06-04

    The subtribe Vampyressina (sensu Baker et al. 2003) encompasses approximately 43 species and seven genera and is a recent and diversified group of New World leaf-nosed bats specialized in fruit eating. The systematics of this group continues to be debated mainly because of the lack of congruence between topologies generated by molecular and morphological data. We analyzed seven species of all genera of vampyressine bats by multidirectional chromosome painting, using whole-chromosome-painting probes from Carollia brevicauda and Phyllostomus hastatus. Phylogenetic analyses were performed using shared discrete chromosomal segments as characters and the Phylogenetic Analysis Using Parsimony (PAUP) software package, using Desmodontinae as outgroup. We also used the Tree Analysis Using New Technology (TNT) software. The result showed a well-supported phylogeny congruent with molecular topologies regarding the sister taxa relationship of Vampyressa and Mesophylla genera, as well as the close relationship between the genus Chiroderma and Vampyriscus. Our results supported the hypothesis that all genera of this subtribe have compound sex chromosome systems that originated from an X-autosome translocation, an ancestral condition observed in the Stenodermatinae. Additional rearrangements occurred independently in the genus Vampyressa and Mesophylla yielding the X1X1X2X2/X1X2Y sex chromosome system. This work presents additional data supporting the hypothesis based on molecular studies regarding the polyphyly of the genus Vampyressa and its sister relationship to Mesophylla.

  12. RNAi drives nonreciprocal translocations at eroding chromosome ends to establish telomere-free linear chromosomes.

    Science.gov (United States)

    Begnis, Martina; Apte, Manasi S; Masuda, Hirohisa; Jain, Devanshi; Wheeler, David Lee; Cooper, Julia Promisel

    2018-04-13

    The identification of telomerase-negative HAATI (heterochromatin amplification-mediated and telomerase-independent) cells, in which telomeres are superseded by nontelomeric heterochromatin tracts, challenged the idea that canonical telomeres are essential for chromosome linearity and raised crucial questions as to how such tracts translocate to eroding chromosome ends and confer end protection. Here we show that HAATI arises when telomere loss triggers a newly recognized illegitimate translocation pathway that requires RNAi factors. While RNAi is necessary for the translocation events that mobilize ribosomal DNA (rDNA) tracts to all chromosome ends (forming "HAATI rDNA " chromosomes), it is dispensable for HAATI rDNA maintenance. Surprisingly, Dicer (Dcr1) plays a separate, RNAi-independent role in preventing formation of the rare HAATI subtype in which a different repetitive element (the subtelomeric element) replaces telomeres. Using genetics and fusions between shelterin components and rDNA-binding proteins, we mapped the mechanism by which rDNA loci engage crucial end protection factors-despite the absence of telomere repeats-and secure end protection. Sequence analysis of HAATI rDNA genomes allowed us to propose RNA and DNA polymerase template-switching models for the mechanism of RNAi-triggered rDNA translocations. Collectively, our results reveal unforeseen roles for noncoding RNAs (ncRNAs) in assembling a telomere-free chromosome end protection device. © 2018 Begnis et al.; Published by Cold Spring Harbor Laboratory Press.

  13. Nuclear structure

    International Nuclear Information System (INIS)

    Eastham, D.A.; Joy, T.

    1986-01-01

    The paper on 'nuclear structure' is the Appendix to the Daresbury (United Kingdom) Annual Report 1985/86, and contains the research work carried out at the Nuclear Structure Facility, Daresbury, within that period. During the year a total of 74 experiments were scheduled covering the main areas of activity including: nuclear collective motion, nuclei far from stability, and nuclear collisions. The Appendix contains brief reports on these experiments and associated theory. (U.K.)

  14. Chromosome diversity and evolution in Liliaceae.

    Science.gov (United States)

    Peruzzi, L; Leitch, I J; Caparelli, K F

    2009-02-01

    There is an extensive literature on the diversity of karyotypes found in genera within Liliaceae, but there has been no attempt to analyse these data within a robust phylogenetic framework. In part this has been due to a lack of consensus on which genera comprise Liliaceae and the relationships between them. Recently, however, this changed with the proposal for a relatively broad circumscription of Liliaceae comprising 15 genera and an improved understanding of the evolutionary relationships between them. Thus there is now the opportunity to examine patterns and trends in chromosome evolution across the family as a whole. Based on an extensive literature survey, karyo-morphometric features for 217 species belonging to all genera in Liliaceae sensu the APG (Angiosperm Phylogeny Group) were obtained. Included in the data set were basic chromosome number, ploidy, chromosome total haploid length (THL) and 13 different measures of karyotype asymmetry. In addition, genome size estimates for all species studied were inferred from THLs using a power regression model constructed from the data set. Trends in karyotype evolution were analysed by superimposing the karyological data onto a phylogenetic framework for Liliaceae. Combining the large amount of data enabled mean karyotypes to be produced, highlighting marked differences in karyotype structure between the 15 genera. Further differences were noted when various parameters for analysing karyotype asymmetry were assessed. By examining the effects of increasing genome size on karyotype asymmetry, it was shown that in many but not all (e.g. Fritillaria and all of Tulipeae) species, the additional DNA was added preferentially to the long arms of the shorter chromosomes rather than being distributed across the whole karyotype. This unequal pattern of DNA addition is novel, contrasting with the equal and proportional patterns of DNA increase previously reported. Overall, the large-scale analyses of karyotype features within a

  15. Nuclear electronics

    International Nuclear Information System (INIS)

    Friese, T.

    1981-09-01

    A short survey is given on nuclear radiation detectors and nuclear electronics. It is written for newcomers and those, who are not very familiar with this technique. Some additional information is given on typical failures in nuclear measurement systems. (orig.) [de

  16. Nuclear power

    International Nuclear Information System (INIS)

    d'Easum, Lille.

    1976-03-01

    An environmentalist's criticism of nuclear energy is given, on a layman's level. Such subjects as conflict of interest in controlling bodies, low-level radiation, reactor safety, liability insurance, thermal pollution, economics, heavy water production, export of nuclear technology, and the history of the anti-nuclear movement are discussed in a sensationalistic tone. (E.C.B.)

  17. Nuclear terrorism

    International Nuclear Information System (INIS)

    2002-01-01

    Recent reports of alleged terrorist plans to build a 'dirty bomb' have heightened longstanding concerns about nuclear terrorism. This briefing outlines possible forms of attack, such as: detonation of a nuclear weapon; attacks involving radioactive materials; attacks on nuclear facilities. Legislation addressing these risks and the UK's strategy for coping with them are also considered

  18. Nuclear weapons, nuclear effects, nuclear war

    Energy Technology Data Exchange (ETDEWEB)

    Bing, G.F.

    1991-08-20

    This paper provides a brief and mostly non-technical description of the militarily important features of nuclear weapons, of the physical phenomena associated with individual explosions, and of the expected or possible results of the use of many weapons in a nuclear war. Most emphasis is on the effects of so-called ``strategic exchanges.``

  19. 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

  20. Regulation of Nuclear Localization of Signaling Proteins by Cytokinin

    Energy Technology Data Exchange (ETDEWEB)

    Kieber, J.J.

    2010-05-01

    Cytokinins are a class of mitogenic plant hormones that play an important role in most aspects of plant development, including shoot and root growth, vascular and photomorphogenic development and leaf senescence. A model for cytokinin perception and signaling has emerged that is similar to bacterial two-component phosphorelays. In this model, binding of cytokinin to the extracellular domain of the Arabidopsis histidine kinase (AHKs) receptors induces autophosphorylation within the intracellular histidine-kinase domain. The phosphoryl group is subsequently transferred to cytosolic Arabidopsis histidine phosphotransfer proteins (AHPs), which have been suggested to translocate to the nucleus in response to cytokinin treatment, where they then transfer the phosphoryl group to nuclear-localized response regulators (Type-A and Type-B ARRs). We examined the effects of cytokinin on AHP subcellular localization in Arabidopsis and, contrary to expectations, the AHPs maintained a constant nuclear/cytosolic distribution following cytokinin treatment. Furthermore, mutation of the conserved phosphoacceptor histidine residue of the AHP, as well as disruption of multiple cytokinin signaling elements, did not affect the subcellular localization of the AHP proteins. Finally, we present data indicating that AHPs maintain a nuclear/cytosolic distribution by balancing active transport into and out of the nucleus. Our findings suggest that the current models indicating relocalization of AHP protein into the nucleus in response to cytokinin are incorrect. Rather, AHPs actively maintain a consistent nuclear/cytosolic distribution regardless of the status of the cytokinin response pathway.