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Datta S, Patel M, Kashyap S, Patel D, Singh U. Chimeric chromosome landscapes of human somatic cell cultures show dependence on stress and regulation of genomic repeats by CGGBP1. Oncotarget 2022; 13:136-155. [PMID: 35070079 PMCID: PMC8765472 DOI: 10.18632/oncotarget.28174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 12/20/2021] [Indexed: 11/25/2022] Open
Abstract
Genomes of somatic cells in culture are prone to spontaneous mutations due to errors in replication and DNA repair. Some of these errors, such as chromosomal fusions, are not rectifiable and subject to selection or elimination in growing cultures. Somatic cell cultures are thus expected to generate background levels of potentially stable chromosomal chimeras. A description of the landscape of such spontaneously generated chromosomal chimeras in cultured cells will help understand the factors affecting somatic mosaicism. Here we show that short homology-associated non-homologous chromosomal chimeras occur in normal human fibroblasts and HEK293T cells at genomic repeats. The occurrence of chromosomal chimeras is enhanced by heat stress and depletion of a repeat regulatory protein CGGBP1. We also present evidence of homologous chromosomal chimeras between allelic copies in repeat-rich DNA obtained by methylcytosine immunoprecipitation. The formation of homologous chromosomal chimeras at Alu and L1 repeats increases upon depletion of CGGBP1. Our data are derived from de novo sequencing from three different cell lines under different experimental conditions and our chromosomal chimera detection pipeline is applicable to long as well as short read sequencing platforms. These findings present significant information about the generation, sensitivity and regulation of somatic mosaicism in human cell cultures.
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Affiliation(s)
- Subhamoy Datta
- HoMeCell Lab, Discipline of Biological Engineering, Indian Institute of Technology Gandhinagar, Gandhinagar, Gujarat 382355, India
| | - Manthan Patel
- HoMeCell Lab, Discipline of Biological Engineering, Indian Institute of Technology Gandhinagar, Gandhinagar, Gujarat 382355, India
- Centre for Genomics and Child Health, Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London E1 2AD, UK
| | - Sukesh Kashyap
- HoMeCell Lab, Discipline of Biological Engineering, Indian Institute of Technology Gandhinagar, Gandhinagar, Gujarat 382355, India
| | - Divyesh Patel
- HoMeCell Lab, Discipline of Biological Engineering, Indian Institute of Technology Gandhinagar, Gandhinagar, Gujarat 382355, India
- Current address: Research Programs Unit, Applied Tumor Genomics Program, Faculty of Medicine, University of Helsinki, Biomedicum, Helsinki 00290, Finland
| | - Umashankar Singh
- HoMeCell Lab, Discipline of Biological Engineering, Indian Institute of Technology Gandhinagar, Gandhinagar, Gujarat 382355, India
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2
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Liehr T. Repetitive Elements in Humans. Int J Mol Sci 2021; 22:ijms22042072. [PMID: 33669810 PMCID: PMC7922087 DOI: 10.3390/ijms22042072] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 02/05/2021] [Accepted: 02/15/2021] [Indexed: 12/21/2022] Open
Abstract
Repetitive DNA in humans is still widely considered to be meaningless, and variations within this part of the genome are generally considered to be harmless to the carrier. In contrast, for euchromatic variation, one becomes more careful in classifying inter-individual differences as meaningless and rather tends to see them as possible influencers of the so-called 'genetic background', being able to at least potentially influence disease susceptibilities. Here, the known 'bad boys' among repetitive DNAs are reviewed. Variable numbers of tandem repeats (VNTRs = micro- and minisatellites), small-scale repetitive elements (SSREs) and even chromosomal heteromorphisms (CHs) may therefore have direct or indirect influences on human diseases and susceptibilities. Summarizing this specific aspect here for the first time should contribute to stimulating more research on human repetitive DNA. It should also become clear that these kinds of studies must be done at all available levels of resolution, i.e., from the base pair to chromosomal level and, importantly, the epigenetic level, as well.
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Affiliation(s)
- Thomas Liehr
- Institute of Human Genetics, Jena University Hospital, Friedrich Schiller University, Am Klinikum 1, D-07747 Jena, Germany
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3
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Potter H, Chial HJ, Caneus J, Elos M, Elder N, Borysov S, Granic A. Chromosome Instability and Mosaic Aneuploidy in Neurodegenerative and Neurodevelopmental Disorders. Front Genet 2019; 10:1092. [PMID: 31788001 PMCID: PMC6855267 DOI: 10.3389/fgene.2019.01092] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 10/09/2019] [Indexed: 12/15/2022] Open
Abstract
Evidence from multiple laboratories has accumulated to show that mosaic neuronal aneuploidy and consequent apoptosis characterizes and may underlie neuronal loss in many neurodegenerative diseases, particularly Alzheimer’s disease and frontotemporal dementia. Furthermore, several neurodevelopmental disorders, including Seckel syndrome, ataxia telangiectasia, Nijmegen breakage syndrome, Niemann–Pick type C, and Down syndrome, have been shown to also exhibit mosaic aneuploidy in neurons in the brain and in other cells throughout the body. Together, these results indicate that both neurodegenerative and neurodevelopmental disorders with apparently different pathogenic causes share a cell cycle defect that leads to mosaic aneuploidy in many cell types. When such mosaic aneuploidy arises in neurons in the brain, it promotes apoptosis and may at least partly underlie the cognitive deficits that characterize the neurological symptoms of these disorders. These findings have implications for both diagnosis and treatment/prevention.
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Affiliation(s)
- Huntington Potter
- Department of Neurology, Rocky Mountain Alzheimer's Disease Center, University of Colorado, Aurora, CO, United States.,Linda Crnic Institute for Down Syndrome, University of Colorado, Aurora, CO, United States
| | - Heidi J Chial
- Department of Neurology, Rocky Mountain Alzheimer's Disease Center, University of Colorado, Aurora, CO, United States.,Linda Crnic Institute for Down Syndrome, University of Colorado, Aurora, CO, United States
| | - Julbert Caneus
- NanoScience Technology Center, University of Central Florida, Orlando, FL, United States
| | - Mihret Elos
- Department of Neurology, Rocky Mountain Alzheimer's Disease Center, University of Colorado, Aurora, CO, United States.,Linda Crnic Institute for Down Syndrome, University of Colorado, Aurora, CO, United States
| | - Nina Elder
- Department of Neurology, Rocky Mountain Alzheimer's Disease Center, University of Colorado, Aurora, CO, United States.,Linda Crnic Institute for Down Syndrome, University of Colorado, Aurora, CO, United States
| | - Sergiy Borysov
- Department of Math and Science, Saint Leo University, Saint Leo, FL, United States
| | - Antoneta Granic
- AGE Research Group, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom.,Newcastle University Institute for Ageing, NIHR Newcastle Biomedical Research Centre, Newcastle upon Tyne, United Kingdom.,Newcastle upon Tyne Hospitals, NHS Foundation Trust, Newcastle upon Tyne, United Kingdom
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4
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Raghuram GV, Chaudhary S, Johari S, Mittra I. Illegitimate and Repeated Genomic Integration of Cell-Free Chromatin in the Aetiology of Somatic Mosaicism, Ageing, Chronic Diseases and Cancer. Genes (Basel) 2019; 10:genes10060407. [PMID: 31142004 PMCID: PMC6628102 DOI: 10.3390/genes10060407] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 05/15/2019] [Accepted: 05/22/2019] [Indexed: 12/19/2022] Open
Abstract
Emerging evidence suggests that an individual is a complex mosaic of genetically divergent cells. Post-zygotic genomes of the same individual can differ from one another in the form of single nucleotide variations, copy number variations, insertions, deletions, inversions, translocations, other structural and chromosomal variations and footprints of transposable elements. High-throughput sequencing has led to increasing detection of mosaicism in healthy individuals which is related to ageing, neuro-degenerative disorders, diabetes mellitus, cardiovascular diseases and cancer. These age-related disorders are also known to be associated with significant increase in DNA damage and inflammation. Herein, we discuss a newly described phenomenon wherein the genome is under constant assault by illegitimate integration of cell-free chromatin (cfCh) particles that are released from the billions of cells that die in the body every day. We propose that such repeated genomic integration of cfCh followed by dsDNA breaks and repair by non-homologous-end-joining as well as physical damage to chromosomes occurring throughout life may lead to somatic/chromosomal mosaicism which would increase with age. We also discuss the recent finding that genomic integration of cfCh and the accompanying DNA damage is associated with marked activation of inflammatory cytokines. Thus, the triple pathologies of somatic mosaicism, DNA/chromosomal damage and inflammation brought about by a common mechanism of genomic integration of cfCh may help to provide an unifying model for the understanding of aetiologies of the inter-related conditions of ageing, degenerative disorders and cancer.
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Affiliation(s)
- Gorantla V Raghuram
- Translational Research Laboratory, Advanced Centre for Treatment, Research and Education in Cancer, Tata Memorial Centre, Navi-Mumbai 410210, India.
| | - Shahid Chaudhary
- Translational Research Laboratory, Advanced Centre for Treatment, Research and Education in Cancer, Tata Memorial Centre, Navi-Mumbai 410210, India.
| | - Shweta Johari
- Translational Research Laboratory, Advanced Centre for Treatment, Research and Education in Cancer, Tata Memorial Centre, Navi-Mumbai 410210, India.
| | - Indraneel Mittra
- Translational Research Laboratory, Advanced Centre for Treatment, Research and Education in Cancer, Tata Memorial Centre, Navi-Mumbai 410210, India.
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Harutyunyan T, Hovhannisyan G, Sargsyan A, Grigoryan B, Al-Rikabi AH, Weise A, Liehr T, Aroutiounian R. Analysis of copy number variations induced by ultrashort electron beam radiation in human leukocytes in vitro. Mol Cytogenet 2019; 12:18. [PMID: 31131024 PMCID: PMC6524226 DOI: 10.1186/s13039-019-0433-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 05/01/2019] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Environmental risk factors have been shown to alter DNA copy number variations (CNVs). Recently, CNVs have been described to arise after low-dose ionizing radiation in vitro and in vivo. Development of cost- and size-effective laser-driven electron accelerators (LDEAs), capable to deliver high energy beams in pico- or femtosecond durations requires examination of their biological effects. Here we studied in vitro impact of LDEAs radiation on known CNV hotspots in human peripheral blood lymphocytes on single cell level. RESULTS Here CNVs in chromosomal regions 1p31.1, 7q11.22, 9q21.3, 10q21.1 and 16q23.1 earlier reported to be sensitive to ionizing radiation were analyzed using molecular cytogenetics. Irradiation of cells with 0.5, 1.5 and 3.0 Gy significantly increased signal intensities in all analyzed chromosomal regions compared to controls. The latter is suggested to be due to radiation-induced duplication or amplification of CNV stretches. As significantly lower gains in mean fluorescence intensities were observed only for chromosomal locus 1p31.1 (after irradiation with 3.0 Gy variant sensitivites of different loci to LDEA is suggested. Negative correlation was found between fluorescence intensities and chromosome size (r = - 0.783, p < 0.001) in cells exposed to 3.0 Gy irradiation and between fluorescence intensities and gene density (r = - 0.475, p < 0.05) in cells exposed to 0.5 Gy irradiation. CONCLUSIONS In this study we demonstrated that irradiation with laser-driven electron bunches can induce molecular-cytogenetically visible CNVs in human blood leukocytes in vitro. These CNVs occur most likely due to duplications or amplification and tend to inversely correlate with chromosome size and gene density. CNVs can last in cell population as stable chromosomal changes for several days after radiation exposure; therefore this endpoint can be used for characterization of genetic effects of accelerated electrons. These findings should be complemented with other studies and implementation of more sophisticated approaches for CNVs analysis.
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Affiliation(s)
- Tigran Harutyunyan
- Department of Genetics and Cytology, Yerevan State University, 1 Alex Manoogian, 0025 Yerevan, Armenia
| | - Galina Hovhannisyan
- Department of Genetics and Cytology, Yerevan State University, 1 Alex Manoogian, 0025 Yerevan, Armenia
| | - Anzhela Sargsyan
- Department of Genetics and Cytology, Yerevan State University, 1 Alex Manoogian, 0025 Yerevan, Armenia
| | - Bagrat Grigoryan
- CANDLE Synchrotron Research Institute, Acharyan 31, 0040 Yerevan, Armenia
| | - Ahmed H. Al-Rikabi
- Institute of Human Genetics, Jena University Hospital, Friedrich Schiller University, D-07740 Jena, Germany
| | - Anja Weise
- Institute of Human Genetics, Jena University Hospital, Friedrich Schiller University, D-07740 Jena, Germany
| | - Thomas Liehr
- Institute of Human Genetics, Jena University Hospital, Friedrich Schiller University, D-07740 Jena, Germany
| | - Rouben Aroutiounian
- Department of Genetics and Cytology, Yerevan State University, 1 Alex Manoogian, 0025 Yerevan, Armenia
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6
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Liehr T. From Human Cytogenetics to Human Chromosomics. Int J Mol Sci 2019; 20:E826. [PMID: 30769866 PMCID: PMC6413437 DOI: 10.3390/ijms20040826] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Revised: 01/30/2019] [Accepted: 02/12/2019] [Indexed: 01/26/2023] Open
Abstract
BACKGROUND The concept of "chromosomics" was introduced by Prof. Uwe Claussen in 2005. Herein, the growing insights into human chromosome structure finally lead to a "chromosomic view" of the three-dimensional constitution and plasticity of genes in interphase nuclei are discussed. This review is dedicated to the memory of Prof. Uwe Claussen (30 April 1945⁻20 July 2008). RECENT FINDINGS Chromosomics is the study of chromosomes, their three-dimensional positioning in the interphase nucleus, the consequences from plasticity of chromosomal subregions and gene interactions, the influence of chromatin-modification-mediated events on cells, and even individuals, evolution, and disease. Progress achieved in recent years is summarized, including the detection of chromosome-chromosome-interactions which, if damaged, lead to malfunction and disease. However, chromosomics in the Human Genetics field is not progressing presently, as research interest has shifted from single cell to high throughput, genomic approaches. CONCLUSION Chromosomics and its impact were predicted correctly in 2005 by Prof. Claussen. Although some progress was achieved, present reconsiderations of the role of the chromosome and the single cell in Human Genetic research are urgently necessary.
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Affiliation(s)
- Thomas Liehr
- Jena University Hospital, Friedrich Schiller University, Institute of Human Genetics, Am Klinikum 1, D-07747 Jena, Germany.
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7
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Yurov YB, Vorsanova SG, Demidova IA, Kravets VS, Vostrikov VM, Soloviev IV, Uranova NA, Iourov IY. [Genomic instability in the brain: chromosomal mosaicism in schizophrenia]. Zh Nevrol Psikhiatr Im S S Korsakova 2018; 116:86-91. [PMID: 28091506 DOI: 10.17116/jnevro201611611186-91] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
AIM Experimental verification of the hypothesis about the possible involvement of the mosaic genome variations (mosaic aneuploidy) in the pathogenesis of a number of mental illnesses, including schizophrenia and autism: a genetic study of the level of mosaic genome variations in cells of the brain autopsy tissues in healthy controls and schizophrenia. MATERIAL AND METHODS Autopsy brain tissues of 15 unaffected controls and 15 patients with schizophrenia were analyzed by molecular cytogenetic methods to determine the frequency of chromosomal mutations (the mosaic aneuploidy) in neural human cells. The original collection of chromosome-enumeration DNA probes to autosomes 1, 9, 15, 16, 18 and the sex chromosomes X and Y was used for the interphase cytogenetic analysis of chromosomes in the cells of the brain. RESULTS AND CONCLUSION The frequency of low-level aneuploidy per individual chromosome was 0.54% (median - 0.53%; 95% confidence interval (CI) CI - 0.41-1.13%) in controls and 1.66% (median - 1.55%; 95% CI -1.32-2.12%) in schizophrenia (p=0.000013). Thus, the three-fold increase in aneuploidy frequency in the brain in schizophrenia was detected. It is suggested that mosaic aneuploidy, as a significant biological marker of genomic instability, may lead to genеtic imbalance and abnormal functional activity of neural cells and neural networks in schizophrenia.
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Affiliation(s)
- Y B Yurov
- Mental Health Research Center, Moscow, Russia; Veltishev Clinical Research Institute of Pediatrics, Moscow, Russia; Pirogov Russian National Research Medical University, Minzdrav RF, Moscow, Russia
| | - S G Vorsanova
- Mental Health Research Center, Moscow, Russia; Veltishev Clinical Research Institute of Pediatrics, Moscow, Russia; Pirogov Russian National Research Medical University, Minzdrav RF, Moscow, Russia
| | - I A Demidova
- Mental Health Research Center, Moscow, Russia; Veltishev Clinical Research Institute of Pediatrics, Moscow, Russia; Pirogov Russian National Research Medical University, Minzdrav RF, Moscow, Russia
| | - V S Kravets
- Mental Health Research Center, Moscow, Russia; Veltishev Clinical Research Institute of Pediatrics, Moscow, Russia; Pirogov Russian National Research Medical University, Minzdrav RF, Moscow, Russia
| | | | | | - N A Uranova
- Mental Health Research Center, Moscow, Russia
| | - I Y Iourov
- Mental Health Research Center, Moscow, Russia; Veltishev Clinical Research Institute of Pediatrics, Moscow, Russia; Pirogov Russian National Research Medical University, Minzdrav RF, Moscow, Russia; Moscow State University of Psychology and Education, Moscow, Russia
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8
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9
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Zhao S, Gibbons JG. A population genomic characterization of copy number variation in the opportunistic fungal pathogen Aspergillus fumigatus. PLoS One 2018; 13:e0201611. [PMID: 30071059 PMCID: PMC6072042 DOI: 10.1371/journal.pone.0201611] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 07/18/2018] [Indexed: 12/19/2022] Open
Abstract
Aspergillus fumigatus is a potentially deadly opportunistic fungal pathogen. Molecular studies have shaped our understanding of the genes, proteins, and molecules that contribute to A. fumigatus pathogenicity, but few studies have characterized genome-wide patterns of genetic variation at the population level. Of A. fumigatus genomic studies to-date, most focus mainly on single nucleotide polymorphisms and large structural variants, while overlooking the contribution of copy number variation (CNV). CNV is a class of small structural variation defined as loci that vary in their number of copies between individuals due to duplication, gain, or deletion. CNV can influence phenotype, including fungal virulence. In the present study, we characterized the population genomic patterns of CNV in a diverse collection of 71 A. fumigatus isolates using publicly available sequencing data. We used genome-wide single nucleotide polymorphisms to infer the population structure of these isolates and identified three populations consisting of at least 8 isolates. We then computationally predicted genome-wide CNV profiles for each isolate and conducted analyses at the species-, population-, and individual levels. Our results suggest that CNV contributes to genetic variation in A. fumigatus, with ~10% of the genome being CN variable. Our analysis indicates that CNV is non-randomly distributed across the A. fumigatus genome, and is overrepresented in subtelomeric regions. Analysis of gene ontology categories in genes that overlapped CN variants revealed an enrichment of genes related to transposable element and secondary metabolism functions. We further identified 72 loci containing 33 genes that showed divergent copy number profiles between the three A. fumigatus populations. Many of these genes encode proteins that interact with the cell surface or are involved in pathogenicity. Our results suggest that CNV is an important source of genetic variation that could account for some of the phenotypic differences between A. fumigatus populations and isolates.
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Affiliation(s)
- Shu Zhao
- Biology Department, Clark University, Worcester, Massachusetts, United States of America
| | - John G. Gibbons
- Biology Department, Clark University, Worcester, Massachusetts, United States of America
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10
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Yurov YB, Vorsanova SG, Demidova IA, Kolotii AD, Soloviev IV, Iourov IY. Mosaic Brain Aneuploidy in Mental Illnesses: An Association of Low-level Post-zygotic Aneuploidy with Schizophrenia and Comorbid Psychiatric Disorders. Curr Genomics 2018; 19:163-172. [PMID: 29606903 PMCID: PMC5850504 DOI: 10.2174/1389202918666170717154340] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2016] [Revised: 11/18/2016] [Accepted: 01/16/2017] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Postzygotic chromosomal variation in neuronal cells is hypothesized to make a substantial contribution to the etiology and pathogenesis of neuropsychiatric disorders. However, the role of somatic genome instability and mosaic genome variations in common mental illnesses is a matter of conjecture. MATERIALS AND METHODS To estimate the pathogenic burden of somatic chromosomal mutations, we determined the frequency of mosaic aneuploidy in autopsy brain tissues of subjects with schizophrenia and other psychiatric disorders (intellectual disability comorbid with autism spectrum disorders). Recently, post-mortem brain tissues of subjects with schizophrenia, intellectual disability and unaffected controls were analyzed by Interphase Multicolor FISH (MFISH), Quantitative Fluorescent in situ Hybridization (QFISH) specially designed to register rare mosaic chromosomal mutations such as lowlevel aneuploidy (whole chromosome mosaic deletion/duplication). The low-level mosaic aneuploidy in the diseased brain demonstrated significant 2-3-fold frequency increase in schizophrenia (p=0.0028) and 4-fold increase in intellectual disability comorbid with autism (p=0.0037) compared to unaffected controls. Strong associations of low-level autosomal/sex chromosome aneuploidy (p=0.001, OR=19.0) and sex chromosome-specific mosaic aneuploidy (p=0.006, OR=9.6) with schizophrenia were revealed. CONCLUSION Reviewing these data and literature supports the hypothesis suggesting that an association of low-level mosaic aneuploidy with common and, probably, overlapping psychiatric disorders does exist. Accordingly, we propose a pathway for common neuropsychiatric disorders involving increased burden of rare de novo somatic chromosomal mutations manifesting as low-level mosaic aneuploidy mediating local and general brain dysfunction.
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Affiliation(s)
- Yuri B. Yurov
- Mental Health Research Center, Moscow, Russian Federation
- Separated Structural Unit “Clinical Research Institute of Pediatrics named after Y.E Veltishev”, Pirogov Russian National Research Medical University, Moscow, Russian Federation
- Moscow State University of Psychology and Education, Moscow, Russian Federation
| | - Svetlana G. Vorsanova
- Mental Health Research Center, Moscow, Russian Federation
- Separated Structural Unit “Clinical Research Institute of Pediatrics named after Y.E Veltishev”, Pirogov Russian National Research Medical University, Moscow, Russian Federation
- Moscow State University of Psychology and Education, Moscow, Russian Federation
| | - Irina A. Demidova
- Mental Health Research Center, Moscow, Russian Federation
- Separated Structural Unit “Clinical Research Institute of Pediatrics named after Y.E Veltishev”, Pirogov Russian National Research Medical University, Moscow, Russian Federation
- Moscow State University of Psychology and Education, Moscow, Russian Federation
| | - Alexei D. Kolotii
- Mental Health Research Center, Moscow, Russian Federation
- Separated Structural Unit “Clinical Research Institute of Pediatrics named after Y.E Veltishev”, Pirogov Russian National Research Medical University, Moscow, Russian Federation
| | | | - Ivan Y. Iourov
- Mental Health Research Center, Moscow, Russian Federation
- Separated Structural Unit “Clinical Research Institute of Pediatrics named after Y.E Veltishev”, Pirogov Russian National Research Medical University, Moscow, Russian Federation
- Department of Medical Genetics, Russian Medical Academy of Postgraduate Education, Ministry of Health, Moscow, Russian Federation
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11
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Liehr T, Schreyer I, Kuechler A, Manolakos E, Singer S, Dufke A, Wilhelm K, Jančušková T, Čmejla R, Othman MAK, Al-Rikabi AH, Mrasek K, Ziegler M, Kankel S, Kreskowski K, Weise A. Parental origin of deletions and duplications - about the necessity to check for cryptic inversions. Mol Cytogenet 2018. [PMID: 29541160 PMCID: PMC5845138 DOI: 10.1186/s13039-018-0369-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Background Copy number variants (CNVs) are the genetic bases for microdeletion/ microduplication syndromes (MMSs). Couples with an affected child and desire to have further children are routinely tested for a potential parental origin of a specific CNV either by molecular karyotyping or by two color fluorescence in situ hybridization (FISH), yet. In the latter case a critical region probe (CRP) is combined with a control probe for identification of the chromosome in question. However, CNVs can arise also due to other reasons, like a recombination-event based on a submicroscopic, cryptic inversion in one of the parents. Results Seventy-four patients with different MMSs and overall 81 CNVs were studied here by a novel three color FISH approach. The way how three locus-specific probes are selected (one is the CRP and two are flanking it in a distance of 5-10 Mb) enables to detect or exclude two possible parental conditions as origins of the CNV seen in the index: (i) direct parental origin of the CNV (deletion or duplication) or (ii) a parental cryptic inversion. Thus, for overall 51/81 CNVs (63%) a parental origin could be determined. 36/51 (70.5%) inherited the CNV directly from one of the parents, but 15/51 (29.5%) were due to an exclusively by three color FISH detectable parental inversion. A 2:1 ratio of maternal versus paternal inheritance was found. Also almost two times more male than female were among the index patients. Conclusion The new, here suggested three color FISH approach is suited for more comprehensive parental studies of patients with MMS. The detection rate for parental origin was increased by 140% in this study. Still, for 30/81 cases (37%) no reason for the ‘de novo’ MMS in the affected index patient could be found by the here suggested FISH-probe set. Electronic supplementary material The online version of this article (10.1186/s13039-018-0369-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Thomas Liehr
- 1Jena University Hospital, Institute of Human Genetics, Friedrich Schiller University, Postfach D-07740, Jena, Germany
| | - Isolde Schreyer
- 1Jena University Hospital, Institute of Human Genetics, Friedrich Schiller University, Postfach D-07740, Jena, Germany.,2Center for Ambulant Medicine, Jena University Hospital, Jena, Germany
| | - Alma Kuechler
- 3Institut für Humangenetik, Universitätsklinikum Essen, Essen, Germany
| | | | - Sylke Singer
- Institut für Medizinische Genetik und angewandte Genomik, Tübingen, Germany
| | - Andreas Dufke
- Institut für Medizinische Genetik und angewandte Genomik, Tübingen, Germany
| | - Kathleen Wilhelm
- 1Jena University Hospital, Institute of Human Genetics, Friedrich Schiller University, Postfach D-07740, Jena, Germany
| | | | - Radek Čmejla
- 6Synlab czech s.r.o., synlab genetics s.r.o, Praha, Czech Republic
| | - Moneeb A K Othman
- 1Jena University Hospital, Institute of Human Genetics, Friedrich Schiller University, Postfach D-07740, Jena, Germany
| | - Ahmed H Al-Rikabi
- 1Jena University Hospital, Institute of Human Genetics, Friedrich Schiller University, Postfach D-07740, Jena, Germany
| | - Kristin Mrasek
- 1Jena University Hospital, Institute of Human Genetics, Friedrich Schiller University, Postfach D-07740, Jena, Germany
| | - Monika Ziegler
- 1Jena University Hospital, Institute of Human Genetics, Friedrich Schiller University, Postfach D-07740, Jena, Germany
| | - Stefanie Kankel
- 1Jena University Hospital, Institute of Human Genetics, Friedrich Schiller University, Postfach D-07740, Jena, Germany
| | - Katharina Kreskowski
- 1Jena University Hospital, Institute of Human Genetics, Friedrich Schiller University, Postfach D-07740, Jena, Germany
| | - Anja Weise
- 1Jena University Hospital, Institute of Human Genetics, Friedrich Schiller University, Postfach D-07740, Jena, Germany
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12
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Sharma A, Ansari AH, Kumari R, Pandey R, Rehman R, Mehani B, Varma B, Desiraju BK, Mabalirajan U, Agrawal A, Mukhopadhyay A. Human brain harbors single nucleotide somatic variations in functionally relevant genes possibly mediated by oxidative stress. F1000Res 2017; 5:2520. [PMID: 28149503 DOI: 10.12688/f1000research.9495.2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/08/2016] [Indexed: 12/11/2022] Open
Abstract
Somatic variation in DNA can cause cells to deviate from the preordained genomic path in both disease and healthy conditions. Here, using exome sequencing of paired tissue samples, we show that the normal human brain harbors somatic single base variations measuring up to 0.48% of the total variations. Interestingly, about 64% of these somatic variations in the brain are expected to lead to non-synonymous changes, and as much as 87% of these represent G:C>T:A transversion events. Further, the transversion events in the brain were mostly found in the frontal cortex, whereas the corpus callosum from the same individuals harbors the reference genotype. We found a significantly higher amount of 8-OHdG (oxidative stress marker) in the frontal cortex compared to the corpus callosum of the same subjects (p<0.01), correlating with the higher G:C>T:A transversions in the cortex. We found significant enrichment for axon guidance and related pathways for genes harbouring somatic variations. This could represent either a directed selection of genetic variations in these pathways or increased susceptibility of some loci towards oxidative stress. This study highlights that oxidative stress possibly influence single nucleotide somatic variations in normal human brain.
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Affiliation(s)
- Anchal Sharma
- Genomics & Molceular Medicine Unit, CSIR-Institute of Genomics & Integrative Biology, Delhi, 110020, India; Academy of Scientific and Innovative Research, CSIR-Institute of Genomics & Integrative Biology (AcSIR-IGIB), Delhi, 110020, India
| | - Asgar Hussain Ansari
- Genomics & Molceular Medicine Unit, CSIR-Institute of Genomics & Integrative Biology, Delhi, 110020, India; Academy of Scientific and Innovative Research, CSIR-Institute of Genomics & Integrative Biology (AcSIR-IGIB), Delhi, 110020, India
| | - Renu Kumari
- Genomics & Molceular Medicine Unit, CSIR-Institute of Genomics & Integrative Biology, Delhi, 110020, India; Academy of Scientific and Innovative Research, CSIR-Institute of Genomics & Integrative Biology (AcSIR-IGIB), Delhi, 110020, India
| | - Rajesh Pandey
- CSIR Ayurgenomics Unit- TRISUTRA, CSIR-Institute of Genomics & Integrative Biology, Delhi, 110020, India
| | - Rakhshinda Rehman
- Academy of Scientific and Innovative Research, CSIR-Institute of Genomics & Integrative Biology (AcSIR-IGIB), Delhi, 110020, India; Molecular Immunogenetics Unit, CSIR-Institute of Genomics & Integrative Biology, Delhi, 110020, India
| | - Bharati Mehani
- Genomics & Molceular Medicine Unit, CSIR-Institute of Genomics & Integrative Biology, Delhi, 110020, India; Academy of Scientific and Innovative Research, CSIR-Institute of Genomics & Integrative Biology (AcSIR-IGIB), Delhi, 110020, India
| | - Binuja Varma
- CSIR Ayurgenomics Unit- TRISUTRA, CSIR-Institute of Genomics & Integrative Biology, Delhi, 110020, India
| | - Bapu K Desiraju
- Academy of Scientific and Innovative Research, CSIR-Institute of Genomics & Integrative Biology (AcSIR-IGIB), Delhi, 110020, India; Molecular Immunogenetics Unit, CSIR-Institute of Genomics & Integrative Biology, Delhi, 110020, India
| | - Ulaganathan Mabalirajan
- Academy of Scientific and Innovative Research, CSIR-Institute of Genomics & Integrative Biology (AcSIR-IGIB), Delhi, 110020, India; Molecular Immunogenetics Unit, CSIR-Institute of Genomics & Integrative Biology, Delhi, 110020, India
| | - Anurag Agrawal
- Academy of Scientific and Innovative Research, CSIR-Institute of Genomics & Integrative Biology (AcSIR-IGIB), Delhi, 110020, India; Molecular Immunogenetics Unit, CSIR-Institute of Genomics & Integrative Biology, Delhi, 110020, India
| | - Arijit Mukhopadhyay
- Genomics & Molceular Medicine Unit, CSIR-Institute of Genomics & Integrative Biology, Delhi, 110020, India; Academy of Scientific and Innovative Research, CSIR-Institute of Genomics & Integrative Biology (AcSIR-IGIB), Delhi, 110020, India; School of Environment and Life Sciences, University of Salford, Manchester, UK
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Sharma A, Ansari AH, Kumari R, Pandey R, Rehman R, Mehani B, Varma B, Desiraju BK, Mabalirajan U, Agrawal A, Mukhopadhyay A. Human brain harbors single nucleotide somatic variations in functionally relevant genes possibly mediated by oxidative stress. F1000Res 2016; 5:2520. [PMID: 28149503 PMCID: PMC5265704 DOI: 10.12688/f1000research.9495.3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/11/2017] [Indexed: 12/14/2022] Open
Abstract
Somatic variation in DNA can cause cells to deviate from the preordained genomic
path in both disease and healthy conditions. Here, using exome sequencing of
paired tissue samples, we show that the normal human brain harbors somatic
single base variations measuring up to 0.48% of the total variations.
Interestingly, about 64% of these somatic variations in the brain are expected
to lead to non-synonymous changes, and as much as 87% of these represent
G:C>T:A transversion events. Further, the transversion events in the brain
were mostly found in the frontal cortex, whereas the corpus callosum from the
same individuals harbors the reference genotype. We found a significantly higher
amount of 8-OHdG (oxidative stress marker) in the frontal cortex compared to the
corpus callosum of the same subjects (p<0.01), correlating with the higher
G:C>T:A transversions in the cortex. We found significant enrichment for axon
guidance and related pathways for genes harbouring somatic variations. This
could represent either a directed selection of genetic variations in these
pathways or increased susceptibility of some loci towards oxidative stress. This
study highlights that oxidative stress possibly influence single nucleotide
somatic variations in normal human brain.
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Affiliation(s)
- Anchal Sharma
- Genomics & Molceular Medicine Unit, CSIR-Institute of Genomics & Integrative Biology, Delhi, 110020, India; Academy of Scientific and Innovative Research, CSIR-Institute of Genomics & Integrative Biology (AcSIR-IGIB), Delhi, 110020, India
| | - Asgar Hussain Ansari
- Genomics & Molceular Medicine Unit, CSIR-Institute of Genomics & Integrative Biology, Delhi, 110020, India; Academy of Scientific and Innovative Research, CSIR-Institute of Genomics & Integrative Biology (AcSIR-IGIB), Delhi, 110020, India
| | - Renu Kumari
- Genomics & Molceular Medicine Unit, CSIR-Institute of Genomics & Integrative Biology, Delhi, 110020, India; Academy of Scientific and Innovative Research, CSIR-Institute of Genomics & Integrative Biology (AcSIR-IGIB), Delhi, 110020, India
| | - Rajesh Pandey
- CSIR Ayurgenomics Unit- TRISUTRA, CSIR-Institute of Genomics & Integrative Biology, Delhi, 110020, India
| | - Rakhshinda Rehman
- Academy of Scientific and Innovative Research, CSIR-Institute of Genomics & Integrative Biology (AcSIR-IGIB), Delhi, 110020, India; Molecular Immunogenetics Unit, CSIR-Institute of Genomics & Integrative Biology, Delhi, 110020, India
| | - Bharati Mehani
- Genomics & Molceular Medicine Unit, CSIR-Institute of Genomics & Integrative Biology, Delhi, 110020, India; Academy of Scientific and Innovative Research, CSIR-Institute of Genomics & Integrative Biology (AcSIR-IGIB), Delhi, 110020, India
| | - Binuja Varma
- CSIR Ayurgenomics Unit- TRISUTRA, CSIR-Institute of Genomics & Integrative Biology, Delhi, 110020, India
| | - Bapu K Desiraju
- Academy of Scientific and Innovative Research, CSIR-Institute of Genomics & Integrative Biology (AcSIR-IGIB), Delhi, 110020, India; Molecular Immunogenetics Unit, CSIR-Institute of Genomics & Integrative Biology, Delhi, 110020, India
| | - Ulaganathan Mabalirajan
- Academy of Scientific and Innovative Research, CSIR-Institute of Genomics & Integrative Biology (AcSIR-IGIB), Delhi, 110020, India; Molecular Immunogenetics Unit, CSIR-Institute of Genomics & Integrative Biology, Delhi, 110020, India
| | - Anurag Agrawal
- Academy of Scientific and Innovative Research, CSIR-Institute of Genomics & Integrative Biology (AcSIR-IGIB), Delhi, 110020, India; Molecular Immunogenetics Unit, CSIR-Institute of Genomics & Integrative Biology, Delhi, 110020, India
| | - Arijit Mukhopadhyay
- Genomics & Molceular Medicine Unit, CSIR-Institute of Genomics & Integrative Biology, Delhi, 110020, India; Academy of Scientific and Innovative Research, CSIR-Institute of Genomics & Integrative Biology (AcSIR-IGIB), Delhi, 110020, India; School of Environment and Life Sciences, University of Salford, Manchester, UK
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Steenwyk JL, Soghigian JS, Perfect JR, Gibbons JG. Copy number variation contributes to cryptic genetic variation in outbreak lineages of Cryptococcus gattii from the North American Pacific Northwest. BMC Genomics 2016; 17:700. [PMID: 27590805 PMCID: PMC5009542 DOI: 10.1186/s12864-016-3044-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Accepted: 08/24/2016] [Indexed: 12/13/2022] Open
Abstract
Background Copy number variants (CNVs) are a class of structural variants (SVs) and are defined as fragments of DNA that are present at variable copy number in comparison with a reference genome. Recent advances in bioinformatics methodologies and sequencing technologies have enabled the high-resolution quantification of genome-wide CNVs. In pathogenic fungi SVs have been shown to alter gene expression, influence host specificity, and drive fungicide resistance, but little attention has focused specifically on CNVs. Using publicly available sequencing data, we identified 90 isolates across 212 Cryptococcus gattii genomes that belong to the VGII subgroups responsible for the recent deadly outbreaks in the North American Pacific Northwest. We generated CNV profiles for each sample to investigate the prevalence and function of CNV in C. gattii. Results We identified eight genetic clusters among publicly available Illumina whole genome sequence data from 212 C. gattii isolates through population structure analysis. Three clusters represent the VGIIa, VGIIb, and VGIIc subgroups from the North American Pacific Northwest. CNV was bioinformatically predicted and affected ~300–400 Kilobases (Kb) of the C. gattii VGII subgroup genomes. Sixty-seven loci, encompassing 58 genes, showed highly divergent patterns of copy number variation between VGII subgroups. Analysis of PFam domains within divergent CN variable genes revealed enrichment of protein domains associated with transport, cell wall organization and external encapsulating structure. Conclusions CNVs may contribute to pathological and phenotypic differences observed between the C. gattii VGIIa, VGIIb, and VGIIc subpopulations. Genes overlapping with population differentiated CNVs were enriched for several virulence related functional terms. These results uncover novel candidate genes to examine the genetic and functional underpinnings of C. gattii pathogenicity. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-3044-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jacob L Steenwyk
- Biology Department, Clark University, 950 Main Street, Worcester, MA, USA.,Current address: Department of Biological Sciences, Vanderbilt University, Nashville, TN, USA
| | - John S Soghigian
- Biology Department, Clark University, 950 Main Street, Worcester, MA, USA.,Current address: Department of Environmental Sciences, The Connecticut Agricultural Experiment Station, New Haven, CT, USA
| | - John R Perfect
- Division of Infectious Diseases, Department of Medicine, Duke University Medical Center, Durham, NC, USA
| | - John G Gibbons
- Biology Department, Clark University, 950 Main Street, Worcester, MA, USA.
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15
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Oluwole OA, Revay T, Mahboubi K, Favetta LA, King WA. Somatic Mosaicism in Bulls Estimated from Genome-Wide CNV Array and TSPY Gene Copy Numbers. Cytogenet Genome Res 2016; 149:176-181. [DOI: 10.1159/000448368] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/28/2016] [Indexed: 11/19/2022] Open
Abstract
Somatic mosaicism has become a focus in human research due to the implications of individual genetic variability in disease. Here, we assessed somatic copy number variations (CNVs) in Holstein bulls in 2 respects. We estimated genome-wide CNVs and assayed CNVs of the TSPY gene, the most variable bovine gene from the Y chromosome. Somatic tissues (blood, lung, heart, muscle, testis, and brain) of 4 bulls were arrayed on the Illumina Bovine SNP50k chip and qPCR tested for TSPY copy numbers. Our results showed extensive copy number divergence in tissues within the same animal as well as significant copy number alterations of TSPY. We detected a mean of 31 CNVs per animal among which 14 were of germline origin, as they were constantly present in all investigated tissues of the animal, while 18 were specific to 1 tissue. Thus, 57% of the total number of detected CNVs was the result of de novo somatic events. Further, TSPY copy number was found to vary significantly among tissues as well as among the same tissue type from different animals in a wide range from 7 to 224% of the calibrator. Our study shows significant autosomal and Y-chromosomal de novo somatic CNV in bulls.
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16
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Malekpour SA, Pezeshk H, Sadeghi M. MGP-HMM: Detecting genome-wide CNVs using an HMM for modeling mate pair insertion sizes and read counts. Math Biosci 2016; 279:53-62. [PMID: 27424951 DOI: 10.1016/j.mbs.2016.07.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Revised: 06/12/2016] [Accepted: 07/10/2016] [Indexed: 01/02/2023]
Abstract
MOTIVATION Association of Copy Number Variation (CNV) with schizophrenia, autism, developmental disabilities and fatal diseases such as cancer is verified. Recent developments in Next Generation Sequencing (NGS) have facilitated the CNV studies. However, many of the current CNV detection tools are not capable of discriminating tandem duplication from non-tandem duplications. RESULTS In this study, we propose MGP-HMM as a tool which besides detecting genome-wide deletions discriminates tandem duplications from non-tandem duplications. MGP-HMM takes mate pair abnormalities into account and predicts the digitized number of tandem or non-tandem copies. Abnormalities in the mate pair directions and insertion sizes, after being mapped to the reference genome, are elucidated using a Hidden Markov Model (HMM). For this purpose, a Mixture Gaussian density with time-dependent parameters is applied for emitting mate pair insertion sizes from HMM states. Indeed, depending on observed abnormalities in mate pair insertion size or its orientation, each component in the mixture density will have different parameters. MGP-HMM also applies a Poisson distribution for modeling read depth data. This parametric modeling of the mate pair reads enables us to estimate the length of CNVs precisely, which is an advantage over methods which rely only on read depth approach for the CNV detection. Hidden state of the proposed HMM is the digitized copy number of a genomic segment and states correspond to the multipliers of the mixture Gaussian components. The accuracy of our model is validated on a set of next generation sequencing real and simulated data and is compared to other tools.
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Affiliation(s)
- Seyed Amir Malekpour
- School of Mathematics, Statistics and Computer Science, College of Science, University of Tehran, Tehran, Iran.
| | - Hamid Pezeshk
- School of Mathematics, Statistics and Computer Science, College of Science, University of Tehran, Tehran, Iran; School of Biological Sciences, Institute for Research in Fundamental Sciences, Tehran, Iran.
| | - Mehdi Sadeghi
- National Institute of Genetic Engineering and Biotechnology, Tehran, Iran.
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17
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Liehr T. Cytogenetically visible copy number variations (CG-CNVs) in banding and molecular cytogenetics of human; about heteromorphisms and euchromatic variants. Mol Cytogenet 2016; 9:5. [PMID: 26807150 PMCID: PMC4724132 DOI: 10.1186/s13039-016-0216-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 01/14/2016] [Indexed: 01/09/2023] Open
Abstract
Background Copy number variations (CNVs) having no (obvious) clinical effects were rediscovered as major part of human genome in 2004. However, for every cytogeneticist microscopically visible harmless CNVs (CG-CNVs) are well known since decades. Harmless CG-CNVs can be present as heterochromatic or even as euchromatic variants in clinically healthy persons. Results Here I provide a review on what is known today on the still too little studied harmless human CG-CNVs, point out which can be mixed up with clinically relevant pathological CG-CNVs and shortly discuss that the artificial separation of euchromatic submicroscopic CNVs (MG-CNVs) and euchromatic CG-CNVs is no longer timely. Conclusion Overall, neither so-called harmless heterochromatic nor so-called harmless euchromatic CG-CNVs are considered enough in evaluation of routine cytogenetic analysis and reporting. This holds especially true when bearing in mind the so-called two-hit model suggesting that combination of per se harmless CNVs may lead to clinical aberrations if they are present together in one patient.
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Affiliation(s)
- Thomas Liehr
- Jena University Hospital, Friedrich Schiller University, Institute of Human Genetics, Kollegiengasse 10, D-07743 Jena, Germany
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18
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A Dishful of a Troubled Mind: Induced Pluripotent Stem Cells in Psychiatric Research. Stem Cells Int 2015; 2016:7909176. [PMID: 26839567 PMCID: PMC4709917 DOI: 10.1155/2016/7909176] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 09/30/2015] [Indexed: 02/06/2023] Open
Abstract
Neuronal differentiation of induced pluripotent stem cells and direct reprogramming represent powerful methods for modeling the development of neurons in vitro. Moreover, this approach is also a means for comparing various cellular phenotypes between cell lines originating from healthy and diseased individuals or isogenic cell lines engineered to differ at only one or a few genomic loci. Despite methodological constraints and initial skepticism regarding this approach, the field is expanding at a fast pace. The improvements include the development of new differentiation protocols resulting in selected neuronal populations (e.g., dopaminergic, GABAergic, hippocampal, and cortical), the widespread use of genome editing methods, and single-cell techniques. A major challenge awaiting in vitro disease modeling is the integration of clinical data in the models, by selection of well characterized clinical populations. Ideally, these models will also demonstrate how different diagnostic categories share overlapping molecular disease mechanisms, but also have unique characteristics. In this review we evaluate studies with regard to the described developments, to demonstrate how differentiation of induced pluripotent stem cells and direct reprogramming can contribute to psychiatry.
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Somatic mosaicism for copy-neutral loss of heterozygosity and DNA copy number variations in the human genome. BMC Genomics 2015; 16:703. [PMID: 26376747 PMCID: PMC4573927 DOI: 10.1186/s12864-015-1916-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Accepted: 09/09/2015] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Somatic mosaicism denotes the presence of genetically distinct populations of somatic cells in one individual who has developed from a single fertilised oocyte. Mosaicism may result from a mutation that occurs during postzygotic development and is propagated to only a subset of the adult cells. Our aim was to investigate both somatic mosaicism for copy-neutral loss of heterozygosity (cn-LOH) events and DNA copy number variations (CNVs) in fully differentiated tissues. RESULTS We studied panels of tissue samples (11-12 tissues per individual) from four autopsy subjects using high-resolution Illumina HumanOmniExpress-12 BeadChips to reveal the presence of possible intra-individual tissue-specific cn-LOH and CNV patterns. We detected five mosaic cn-LOH regions >5 Mb in some tissue samples in three out of four individuals. We also detected three CNVs that affected only a portion of the tissues studied in one out of four individuals. These three somatic CNVs range from 123 to 796 kb and are also found in the general population. An attempt was made to explain the succession of genomic events that led to the observed somatic genetic mosaicism under the assumption that the specific mosaic patterns of CNV and cn-LOH changes reflect their formation during the postzygotic embryonic development of germinal layers and organ systems. CONCLUSIONS Our results give further support to the idea that somatic mosaicism for CNVs, and also cn-LOHs, is a common phenomenon in phenotypically normal humans. Thus, the examination of only a single tissue might not provide enough information to diagnose potentially deleterious CNVs within an individual. During routine CNV and cn-LOH analysis, DNA derived from a buccal swab can be used in addition to blood DNA to get information about the CNV/cn-LOH content in tissues of both mesodermal and ectodermal origin. Currently, the real frequency and possible phenotypic consequences of both CNVs and cn-LOHs that display somatic mosaicism remain largely unknown. To answer these questions, future studies should involve larger cohorts of individuals and a range of tissues.
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Sakai M, Watanabe Y, Someya T, Araki K, Shibuya M, Niizato K, Oshima K, Kunii Y, Yabe H, Matsumoto J, Wada A, Hino M, Hashimoto T, Hishimoto A, Kitamura N, Iritani S, Shirakawa O, Maeda K, Miyashita A, Niwa SI, Takahashi H, Kakita A, Kuwano R, Nawa H. Assessment of copy number variations in the brain genome of schizophrenia patients. Mol Cytogenet 2015; 8:46. [PMID: 26136833 PMCID: PMC4487564 DOI: 10.1186/s13039-015-0144-5] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 05/12/2015] [Indexed: 11/28/2022] Open
Abstract
Background Cytogenomic mutations and chromosomal abnormality are implicated in the neuropathology of several brain diseases. Cell heterogeneity of brain tissues makes their detection and validation difficult, however. In the present study, we analyzed gene dosage alterations in brain DNA of schizophrenia patients and compared those with the copy number variations (CNVs) identified in schizophrenia patients as well as with those in Asian lymphocyte DNA and attempted to obtain hints at the pathological contribution of cytogenomic instability to schizophrenia. Results Brain DNA was extracted from postmortem striatum of schizophrenia patients and control subjects (n = 48 each) and subjected to the direct two color microarray analysis that limits technical data variations. Disease-associated biases of relative DNA doses were statistically analyzed with Bonferroni’s compensation on the premise of brain cell mosaicism. We found that the relative gene dosage of 85 regions significantly varied among a million of probe sites. In the candidate CNV regions, 26 regions had no overlaps with the common CNVs found in Asian populations and included the genes (i.e., ANTXRL, CHST9, DNM3, NDST3, SDK1, STRC, SKY) that are associated with schizophrenia and/or other psychiatric diseases. The majority of these candidate CNVs exhibited high statistical probabilities but their signal differences in gene dosage were less than 1.5-fold. For test evaluation, we rather selected the 10 candidate CNV regions that exhibited higher aberration scores or larger global effects and were thus confirmable by PCR. Quantitative PCR verified the loss of gene dosage at two loci (1p36.21 and 1p13.3) and confirmed the global variation of the copy number distributions at two loci (11p15.4 and 13q21.1), both indicating the utility of the present strategy. These test loci, however, exhibited the same somatic CNV patterns in the other brain region. Conclusions The present study lists the candidate regions potentially representing cytogenomic CNVs in the brain of schizophrenia patients, although the significant but modest alterations in their brain genome doses largely remain to be characterized further. Electronic supplementary material The online version of this article (doi:10.1186/s13039-015-0144-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Miwako Sakai
- Department of Molecular Neurobiology, Brain Research Institute, Niigata University, 1-757, Asahimachi-dori, 951-8585 Niigata, Japan ; Department of Psychiatry, Graduate School of Medical and Dental Sciences, Niigata University, 1-757, Asahimachi-dori, 951-8510 Niigata, Japan
| | - Yuichiro Watanabe
- Department of Psychiatry, Graduate School of Medical and Dental Sciences, Niigata University, 1-757, Asahimachi-dori, 951-8510 Niigata, Japan
| | - Toshiyuki Someya
- Department of Psychiatry, Graduate School of Medical and Dental Sciences, Niigata University, 1-757, Asahimachi-dori, 951-8510 Niigata, Japan
| | - Kazuaki Araki
- Department of Molecular Neurobiology, Brain Research Institute, Niigata University, 1-757, Asahimachi-dori, 951-8585 Niigata, Japan
| | - Masako Shibuya
- Department of Psychiatry, Graduate School of Medical and Dental Sciences, Niigata University, 1-757, Asahimachi-dori, 951-8510 Niigata, Japan
| | | | | | - Yasuto Kunii
- Departments of Neuropsychiatry, Fukushima Medical University School of Medicine, 960-1295 Fukushima, Japan
| | - Hirooki Yabe
- Departments of Neuropsychiatry, Fukushima Medical University School of Medicine, 960-1295 Fukushima, Japan
| | - Junya Matsumoto
- Departments of Neuropsychiatry, Fukushima Medical University School of Medicine, 960-1295 Fukushima, Japan
| | - Akira Wada
- Departments of Neuropsychiatry, Fukushima Medical University School of Medicine, 960-1295 Fukushima, Japan
| | - Mizuki Hino
- Departments of Neuropsychiatry, Fukushima Medical University School of Medicine, 960-1295 Fukushima, Japan
| | - Takeshi Hashimoto
- Division of Psychiatry and Neurology, Kobe University Graduate School of Medicine, 650-0017 Kobe, Hyogo Japan
| | - Akitoyo Hishimoto
- Division of Psychiatry and Neurology, Kobe University Graduate School of Medicine, 650-0017 Kobe, Hyogo Japan
| | - Noboru Kitamura
- Division of Psychiatry and Neurology, Kobe University Graduate School of Medicine, 650-0017 Kobe, Hyogo Japan
| | - Shuji Iritani
- Matsuzawa Hospital, Setagaya-ku, 156-0057 Tokyo, Japan ; Department of Mental Health, Nagoya University Graduate School of Medicine, 466-8550 Nagoya, Aichi Japan
| | - Osamu Shirakawa
- Division of Psychiatry and Neurology, Kobe University Graduate School of Medicine, 650-0017 Kobe, Hyogo Japan ; Department of Neuropsychiatry, Kinki University Faculty of Medicine, 589-8511 Osaka-Sayama, Osaka Japan
| | - Kiyoshi Maeda
- Division of Psychiatry and Neurology, Kobe University Graduate School of Medicine, 650-0017 Kobe, Hyogo Japan ; Department of Social Rehabilitation, Kobe University School of Medicine, 654-0142 Hyogo, Japan
| | - Akinori Miyashita
- Department of Molecular Genetics, Brain Research Institute, Niigata University, 951-8585 Niigata, Japan
| | - Shin-Ichi Niwa
- Departments of Neuropsychiatry, Fukushima Medical University School of Medicine, 960-1295 Fukushima, Japan
| | - Hitoshi Takahashi
- Pathology and Brain Disease Research Center, Brain Research Institute, Niigata University, 951-8585 Niigata, Japan
| | - Akiyoshi Kakita
- Pathology and Brain Disease Research Center, Brain Research Institute, Niigata University, 951-8585 Niigata, Japan
| | - Ryozo Kuwano
- Department of Molecular Genetics, Brain Research Institute, Niigata University, 951-8585 Niigata, Japan
| | - Hiroyuki Nawa
- Department of Molecular Neurobiology, Brain Research Institute, Niigata University, 1-757, Asahimachi-dori, 951-8585 Niigata, Japan
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Abstract
Copy number variations (CNVs) are structural variations of the human genome. These alterations result in variant copy numbers of certain stretches of DNA. In other words, some regions may be present in more or less copies than in a reference genome; however, these copy number changes do not have any impact on the phenotype. Also, CNVs may be extremely large and cytogenetically detectable or submicroscopic but still spanning several megabasepairs (Mb). In the recent years, array technology has identified especially the latter ones as so-called copy number variant (CNV) polymorphisms. These CNVs are detected in ~12 % of the human genome sequences and may comprise several hundred kilobasepairs. CNVs contribute significantly to the inter-individual differences in humans, and can range between 0.5 and 1.5 Mb amongst different genomes, well within the level of detection using cytogenetics techniques. Thus, they can be visualized by FISH using bacterial artificial chromosomes (BACs) as probes. Here we describe a method that enables discrimination of individual homologous chromosomes at the single cell level based on CNVs in the genome, called parental origin determination fluorescence in situ hybridization (POD-FISH). Possible fields of applications of this single cell-directed approach are in analyses of the parental origin of single chromosomes in inherited and acquired chromosomal aberrations.
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22
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Cui H, Dhroso A, Johnson N, Korkin D. The variation game: Cracking complex genetic disorders with NGS and omics data. Methods 2015; 79-80:18-31. [PMID: 25944472 DOI: 10.1016/j.ymeth.2015.04.018] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2014] [Revised: 03/27/2015] [Accepted: 04/17/2015] [Indexed: 12/14/2022] Open
Abstract
Tremendous advances in Next Generation Sequencing (NGS) and high-throughput omics methods have brought us one step closer towards mechanistic understanding of the complex disease at the molecular level. In this review, we discuss four basic regulatory mechanisms implicated in complex genetic diseases, such as cancer, neurological disorders, heart disease, diabetes, and many others. The mechanisms, including genetic variations, copy-number variations, posttranscriptional variations, and epigenetic variations, can be detected using a variety of NGS methods. We propose that malfunctions detected in these mechanisms are not necessarily independent, since these malfunctions are often found associated with the same disease and targeting the same gene, group of genes, or functional pathway. As an example, we discuss possible rewiring effects of the cancer-associated genetic, structural, and posttranscriptional variations on the protein-protein interaction (PPI) network centered around P53 protein. The review highlights multi-layered complexity of common genetic disorders and suggests that integration of NGS and omics data is a critical step in developing new computational methods capable of deciphering this complexity.
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Affiliation(s)
- Hongzhu Cui
- Department of Computer Science, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609, United States
| | - Andi Dhroso
- Department of Computer Science, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609, United States
| | - Nathan Johnson
- Department of Computer Science, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609, United States
| | - Dmitry Korkin
- Department of Computer Science, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609, United States; Bioinformatics and Computational Biology Program, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609, United States
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Liehr T, Othman MAK, Rittscher K, Alhourani E. The current state of molecular cytogenetics in cancer diagnosis. Expert Rev Mol Diagn 2015; 15:517-26. [PMID: 25664836 DOI: 10.1586/14737159.2015.1013032] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Cytogenetics and molecular cytogenetics are and will continue to be indispensable tools in cancer diagnostics. Leukemia and lymphoma diagnostics are still emphases of routine (molecular) cytogenetics and corresponding studies of solid tumors gain more and more prominence. Here, first a historical perspective of molecular tumor cytogenetics is provided, which is followed by the basic principles of the fluorescence in situ hybridization (FISH) approach. Finally the current state of molecular cytogenetics in cancer diagnostics is discussed. Nowadays routine diagnostics includes basic FISH approaches rather than multicolor-FISH. The latter together with modern high-throughput methods have their impact on research to identify new tumor-associated genomic regions.
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Affiliation(s)
- Thomas Liehr
- Jena University Hospital, Friedrich Schiller University, Institute of Human Genetics, Kollegiengasse 10, Postfach, D-07743 Jena, Germany
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Somatic mosaicism in esophageal atresia. Am J Gastroenterol 2014; 109:1954-6. [PMID: 25470589 DOI: 10.1038/ajg.2014.346] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Revised: 09/01/2014] [Accepted: 10/06/2014] [Indexed: 12/11/2022]
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Abstract
Zusammenfassung
Das gesunde menschliche Gehirn weist ein bemerkenswert hohes Maß an somatischen Zellmosaiken auf. Zum einen ist dies altersassoziiert, und darüber hinaus wurde nachgewiesen, dass stärker ausgeprägte Zellmosaike im Gehirn Grundlage für neurologische und/oder psychiatrische Störungen (z. B. Alzheimer-Krankheit oder Schizophrenie) sind bzw. damit im Zusammenhang stehen. Möglicherweise eröffnen diese neueren Erkenntnisse künftig Anwendungsmöglichkeiten für die klinische Diagnostik, z. B. in Kombination mit neuen Biomarkern. In diesem Zusammenhang könnte eine vielversprechende Perspektive die Erforschung molekularer Signalwege sein, die die Zellen vor Genom- und/oder Chromosomeninstabilität schützen könnten.
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Affiliation(s)
- Ivan Y. Iourov
- Aff1 grid.466123.4 National Research Center for Mental Health Russian Academy of Medical Sciences Zgorodnoe sh. 2 117152 Moscow Russische Föderation
- Aff2 grid.415738.c 0000000092162496 Institute of Pediatrics and Children Surgery Russian Federation Ministry of Health Moscow Russische Föderation
- Aff3 grid.465497.d Department of Medical Genetics Russian Medical Academy of Postgraduate Education Moscow Russische Föderation
| | - Svetlana G. Vorsanova
- Aff1 grid.466123.4 National Research Center for Mental Health Russian Academy of Medical Sciences Zgorodnoe sh. 2 117152 Moscow Russische Föderation
- Aff2 grid.415738.c 0000000092162496 Institute of Pediatrics and Children Surgery Russian Federation Ministry of Health Moscow Russische Föderation
- Aff4 grid.466944.d Moscow City University of Psychology and Education Moscow Russische Föderation
| | - Thomas Liehr
- Aff5 grid.10388.32 0000000122403300 Jena University Hospital, Friedrich Schiller University Institute of Human Genetics Kollegiengasse 10 07743 Jena Deutschland
| | - Yuri B. Yurov
- Aff1 grid.466123.4 National Research Center for Mental Health Russian Academy of Medical Sciences Zgorodnoe sh. 2 117152 Moscow Russische Föderation
- Aff2 grid.415738.c 0000000092162496 Institute of Pediatrics and Children Surgery Russian Federation Ministry of Health Moscow Russische Föderation
- Aff4 grid.466944.d Moscow City University of Psychology and Education Moscow Russische Föderation
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Liehr T. Entstehungsmechanismen von Zellmosaiken. MED GENET-BERLIN 2014. [DOI: 10.1007/s11825-014-0007-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Zusammenfassung
Zellmosaike bilden sich im Zusammenhang mit „nondisjunction“, Translokationen (balanciert oder unbalanciert), nichthomologem „crossing over“ oder sonstigen chromosomalen oder subchromosomalen „rearrangements“ aus, aber auch durch kompletten oder gewebsspezifischen Chimärismus. Am bekanntesten und häufigsten nachgewiesen sind Zellmosaike, die auf Aneuploidien beruhen, während über die Häufigkeit von submikroskopischen, nur molekulargenetisch oder zytogenetisch nachweisbaren, aber niedriggradigen Zellmosaiken nur wenig bekannt ist. Als Grundlage für die Entstehung von Zellmosaiken gelten „Trisomic“- und/oder „Monosomic-rescue“-Vorgänge. Auch „replikative Fehler“ oder „Endoreduplikation“ einzelner oder mehrere Chromosomen, Isochromosomenbildung oder postzygotisches „non-homologous crossing-over“ werden als Entstehungsmechanismen von Zellmosaiken in der Literatur genannt. Insgesamt ist jedoch festzustellen, dass praktisch alle bekannten Modelle zur Mosaikentstehung bislang auf der deskriptiven Ebene verharren. Ein grundlegendes Verständnis über die tatsächlich z. B. beim Trisomic oder Monosomic rescue ablaufenden Vorgänge ist derzeit mangels Daten nicht vorhanden.
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Affiliation(s)
- Thomas Liehr
- Aff1 Institute of Human Genetics Jena Universitätsklinik, Friedrich-Schiller-Universität Kollegiengasse 10 07743 Jena Deutschland
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Kalantari H, Asia S, Totonchi M, Vazirinasab H, Mansouri Z, Zarei Moradi S, Haratian K, Gourabi H, Mohseni Meybodi A. Delineating the association between isodicentric chromosome Y and infertility: a retrospective study. Fertil Steril 2014; 101:1091-6. [DOI: 10.1016/j.fertnstert.2013.12.048] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Revised: 12/28/2013] [Accepted: 12/30/2013] [Indexed: 02/07/2023]
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Jung SH, Yim SH, Oh HJ, Park JE, Kim MJ, Kim GA, Kim TM, Kim JS, Lee BC, Chung YJ. De novo copy number variations in cloned dogs from the same nuclear donor. BMC Genomics 2013; 14:863. [PMID: 24313905 PMCID: PMC3878922 DOI: 10.1186/1471-2164-14-863] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Accepted: 12/03/2013] [Indexed: 11/23/2022] Open
Abstract
Background Somatic mosaicism of copy number variants (CNVs) in human body organs and de novo CNV event in monozygotic twins suggest that de novo CNVs can occur during mitotic recombination. These de novo CNV events are important for understanding genetic background of evolution and diverse phenotypes. In this study, we explored de novo CNV event in cloned dogs with identical genetic background. Results We analyzed CNVs in seven cloned dogs using the nuclear donor genome as reference by array-CGH, and identified five de novo CNVs in two of the seven clones. Genomic qPCR, dye-swap array-CGH analysis and B-allele profile analysis were used for their validation. Two larger de novo CNVs (5.2 Mb and 338 Kb) on chromosomes X and 19 in clone-3 were consistently validated by all three experiments. The other three smaller CNVs (sized from 36.1 to76.4 Kb) on chromosomes 2, 15 and 32 in clone-3 and clone-6 were verified by at least one of the three validations. In addition to the de novo CNVs, we identified a 37 Mb-sized copy neutral de novo loss of heterozygosity event on chromosome 2 in clone-6. Conclusions To our knowledge, this is the first report of de novo CNVs in the cloned dogs which were generated by somatic cell nuclear transfer technology. To study de novo genetic events in cloned animals can help understand formation mechanisms of genetic variants and their biological implications.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Byeong Chun Lee
- Integrated Research Center for Genome Polymorphism, Department of Microbiology, The Catholic University of Korea, College of Medicine, 505 Banpo-dong, Seocho-gu, Seoul 137-701, Korea.
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Ezawa K, Innan H. Theoretical framework of population genetics with somatic mutations taken into account: application to copy number variations in humans. Heredity (Edinb) 2013; 111:364-74. [PMID: 23981956 DOI: 10.1038/hdy.2013.59] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Revised: 01/05/2013] [Accepted: 05/10/2013] [Indexed: 11/09/2022] Open
Abstract
Traditionally, population genetics focuses on the dynamics of frequencies of alleles acquired by mutations on germ-lines, because only such mutations are heritable. Typical genotyping experiments, however, use DNA from some somatic tissues such as blood, which harbors somatic mutations at the current generation in addition to germ-line mutations accumulated since the most recent common ancestor of the sample. This common practice may sometimes cause erroneous interpretations of polymorphism data, unless we properly understand the role of somatic mutations in population genetics. We here introduce a very basic theoretical framework of population genetics with somatic mutations taken into account. It is easy to imagine that somatic mutations at the current generation simply add individual-specific variations, as errors in mutation detection do. Our theory quantifies this increment under various conditions. We find that the major contribution of somatic mutations plus errors is to very rare variants, particularly to singletons. The relative contribution is markedly large when mutations are deleterious. Because negative selection also increases rare variants, it is important to distinguish the roles of these mutually confounding factors when we interpret the data, even after correcting for demography. We apply this theory to human copy number variations (CNVs), for which the composite effect of somatic mutations and errors may not be negligible. Using genome-wide CNV data, we demonstrate how the joint action of the two factors, selection and somatic mutations plus errors, shapes the observed pattern of polymorphism.
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Affiliation(s)
- K Ezawa
- School of Advanced Sciences, The Graduate University for Advanced Studies, Hayama, Japan
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Abstract
Copy number variations (CNVs) encompass a variety of genetic alterations including deletions and amplifications and cluster in regions of the human genome with intrinsic instability. Small-sized CNVs can act as initial genetic changes giving rise to larger CNVs such as acquired somatic copy number aberrations (CNAs) promoting cancer formation. Previous studies provided evidence for CNVs as an underlying cause of elevated breast cancer risk when targeting breast cancer susceptibility genes and of accelerated breast cancer progression when targeting oncogenes. With the development of novel techniques for genome-wide detection of CNVs at increasingly higher resolution, it became possible to qualitatively and quantitatively analyse manifestation of DNA damage resulting from defects in any of the large variety of DNA double-strand break (DSB) repair mechanisms. Breast carcinogenesis, particularly in familial cases, has been linked with a defect in the homologous recombination (HR) pathway, which in turn switches damage removal towards alternative, more error-prone DSB repair pathways such as microhomology-mediated non-homologous end joining (mmNHEJ). Indeed, increased error-prone DSB repair activities were detected in peripheral blood lymphocytes from individuals with familial breast cancer risk independently of specific gene mutations. Intriguingly, sequence analysis of breakpoint regions revealed that the majority of genome aberrations found in breast cancer specimens are formed by mmNHEJ. Detection of pathway-specific error-prone DSB repair activities by functional testing was proposed to serve as biomarker for hereditary breast cancer risk and responsiveness to therapies targeting HR dysfunction. Identification of specific error-prone DSB repair mechanisms underlying CNAs and ultimately mammary tumour formation highlights potential targets for future breast cancer prevention regimens.
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Danjoh I, Shirota R, Hiroyama T, Nakamura Y. Dominant expansion of a cryptic subclone with an abnormal karyotype in B lymphoblastoid cell lines during culture. Cytogenet Genome Res 2012; 139:88-96. [PMID: 23128794 DOI: 10.1159/000343757] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/17/2012] [Indexed: 11/19/2022] Open
Abstract
Although B lymphoblastoid cell lines (B-LCLs) are thought to maintain their original genomic structures during long-term culture, there has been considerable disagreement on the actual genomic stability of these cells. This study was initiated to determine whether B-LCLs develop cell populations with abnormal genomes during culture and to search for factors important to the maintenance of the original genome. We established continuous cultures of B-LCLs for more than 6 months and analyzed the cells using array-based comparative genome hybridization (CGH) analysis, conventional karyotyping and analysis of V(D)J recombination in the immunoglobulin (Ig) gene. We found that one B-LCL acquired an extra chromosome 4 without any other genomic rearrangements at passage 16 of continuous culture. At the Ig light- and heavy-chain loci, analysis of the major cell population showed a difference between cultures at early and later passages. Another aneuploid line was detected among B-LCLs established elsewhere and deposited previously into the RIKEN Cell Bank. Our findings indicate that some of the genomic rearrangements in B-LCLs are not caused by gradual accumulation of mutations and rearrangements during the B-LCL establishment processes, but rather as a result of a change in the cell population from clones with a normal genome to clones with de novo rearrangements. It is therefore feasible to maintain B-LCLs with a normal genomic structure by cell cloning or similar treatment.
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Affiliation(s)
- I Danjoh
- Cell Engineering Division, RIKEN BioResource Center, Tsukuba, Japan
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Corrales NLL, Mrasek K, Voigt M, Liehr T, Kosyakova N. Copy number variations (CNVs) in human pluripotent cell-derived neuroprogenitors. Gene 2012; 506:377-9. [PMID: 22820389 DOI: 10.1016/j.gene.2012.07.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2012] [Revised: 07/03/2012] [Accepted: 07/05/2012] [Indexed: 01/22/2023]
Abstract
Results from the analysis of copy number variations (CNVs) in human pluripotent cell-derived neuroprogenitor cell lines (hiPSC and hESC-derived NPC) are presented. Two different types of CNVs were detected: a) CNVs inherited from the original source of pluripotent cells (hESC and hiPSC) and b) CNVs detected either in the original source of pluripotent cells or in the derived NPC cell lines but not in both at the same time. Our data suggest that submicroscopic chromosomal changes happened during culture and manipulation of cells and those differentiation procedures could result in gains and losses of genomic regions in pluripotent cell-derived neuroprogenitors. Overall, the results indicate that even chromosomally stable stem cell lines would need to be analyzed in detail by high resolution methodologies before their clinical use.
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Krepischi AC, Achatz MIW, Santos EM, Costa SS, Lisboa BC, Brentani H, Santos TM, Gonçalves A, Nóbrega AF, Pearson PL, Vianna-Morgante AM, Carraro DM, Brentani RR, Rosenberg C. Germline DNA copy number variation in familial and early-onset breast cancer. Breast Cancer Res 2012; 14:R24. [PMID: 22314128 PMCID: PMC3496142 DOI: 10.1186/bcr3109] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2011] [Revised: 01/20/2012] [Accepted: 02/07/2012] [Indexed: 11/10/2022] Open
Abstract
Introduction Genetic factors predisposing individuals to cancer remain elusive in the majority of patients with a familial or clinical history suggestive of hereditary breast cancer. Germline DNA copy number variation (CNV) has recently been implicated in predisposition to cancers such as neuroblastomas as well as prostate and colorectal cancer. We evaluated the role of germline CNVs in breast cancer susceptibility, in particular those with low population frequencies (rare CNVs), which are more likely to cause disease." Methods Using whole-genome comparative genomic hybridization on microarrays, we screened a cohort of women fulfilling criteria for hereditary breast cancer who did not carry BRCA1/BRCA2 mutations. Results The median numbers of total and rare CNVs per genome were not different between controls and patients. A total of 26 rare germline CNVs were identified in 68 cancer patients, however, a proportion that was significantly different (P = 0.0311) from the control group (23 rare CNVs in 100 individuals). Several of the genes affected by CNV in patients and controls had already been implicated in cancer. Conclusions This study is the first to explore the contribution of germline CNVs to BRCA1/2-negative familial and early-onset breast cancer. The data suggest that rare CNVs may contribute to cancer predisposition in this small cohort of patients, and this trend needs to be confirmed in larger population samples.
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Affiliation(s)
- Ana Cv Krepischi
- National Institute of Science and Technology in Oncogenomics, AC Camargo Hospital, Rua Taguá 440, 01508-010, São Paulo, Brazil.
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Cuturilo G, Menten B, Krstic A, Drakulic D, Jovanovic I, Parezanovic V, Stevanovic M. 4q34.1-q35.2 deletion in a boy with phenotype resembling 22q11.2 deletion syndrome. Eur J Pediatr 2011; 170:1465-70. [PMID: 21833498 DOI: 10.1007/s00431-011-1533-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2011] [Accepted: 07/05/2011] [Indexed: 01/30/2023]
Abstract
UNLABELLED Small terminal or interstitial deletions involving bands 4q34 and 4q35 have been described in several patients with a relatively mild phenotype such as mild to moderate intellectual disability and minor dysmorphic features. We present a boy born from unrelated parents with a de novo 4q34.1-q35.2 deletion and clinical features resembling 22q11.2 deletion syndrome. To the best of our knowledge, this is the first reported patient with 4q34-q35 deletion and phenotype resembling 22q11.2 deletion syndrome without fifth finger anomalies as a specific feature of 4q- syndrome. G-banding karyotyping disclosed the deletion, which was further delineated by microarray comparative genomic hybridization. Fluorescence in situ hybridization and multiplex ligation-dependent probe amplification analyses did not reveal rearrangements of 22q11.2 region. MLPA confirmed the deletion within the 4q35.2 region. CONCLUSION Given the considerable clinical overlaps between the 22q11.2 deletion syndrome and clinical manifestation of the patient described in this study, we propose that region 4q34.1-q35.2 should be considered as another region associated with phenotype resembling 22q11.2 deletion syndrome. We also propose that distal 4q deletions should be considered in the evaluation of patients with phenotypic manifestations resembling 22q11.2 deletion syndrome in whom no 22q11.2 microdeletion was detected, even in the absence of distinctive fifth finger anomalies. Additionally, we underline the importance of applying array CGH that enables simultaneous genome-wide detection and delineation of copy number changes (e.g., deletions and duplications).
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Affiliation(s)
- Goran Cuturilo
- Faculty of Medicine, University of Belgrade, Belgrade, Serbia.
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