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Deane-Coe PE, Chu ET, Slavney A, Boyko AR, Sams AJ. Direct-to-consumer DNA testing of 6,000 dogs reveals 98.6-kb duplication associated with blue eyes and heterochromia in Siberian Huskies. PLoS Genet 2018; 14:e1007648. [PMID: 30286082 PMCID: PMC6171790 DOI: 10.1371/journal.pgen.1007648] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Accepted: 08/20/2018] [Indexed: 12/30/2022] Open
Abstract
Consumer genomics enables genetic discovery on an unprecedented scale by linking very large databases of personal genomic data with phenotype information voluntarily submitted via web-based surveys. These databases are having a transformative effect on human genomics research, yielding insights on increasingly complex traits, behaviors, and disease by including many thousands of individuals in genome-wide association studies (GWAS). The promise of consumer genomic data is not limited to human research, however. Genomic tools for dogs are readily available, with hundreds of causal Mendelian variants already characterized, because selection and breeding have led to dramatic phenotypic diversity underlain by a simple genetic structure. Here, we report the results of the first consumer genomics study ever conducted in a non-human model: a GWAS of blue eyes based on more than 3,000 customer dogs with validation panels including nearly 3,000 more, the largest canine GWAS to date. We discovered a novel association with blue eyes on chromosome 18 (P = 1.3x10-68) and used both sequence coverage and microarray probe intensity data to identify the putative causal variant: a 98.6-kb duplication directly upstream of the Homeobox gene ALX4, which plays an important role in mammalian eye development. This duplication is largely restricted to Siberian Huskies, is strongly associated with the blue-eyed phenotype (chi-square P = 5.2x10-290), and is highly, but not completely, penetrant. These results underscore the power of consumer-data-driven discovery in non-human species, especially dogs, where there is intense owner interest in the personal genomic information of their pets, a high level of engagement with web-based surveys, and an underlying genetic architecture ideal for mapping studies.
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Affiliation(s)
- Petra E. Deane-Coe
- Embark Veterinary, Inc., Boston, Massachusetts, United States of America
| | - Erin T. Chu
- Embark Veterinary, Inc., Boston, Massachusetts, United States of America
| | - Andrea Slavney
- Embark Veterinary, Inc., Boston, Massachusetts, United States of America
| | - Adam R. Boyko
- Embark Veterinary, Inc., Boston, Massachusetts, United States of America
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, United States of America
| | - Aaron J. Sams
- Embark Veterinary, Inc., Boston, Massachusetts, United States of America
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Du J, Kirk B, Zeng J, Ma J, Wang Q. Three classes of response elements for human PRC2 and MLL1/2-Trithorax complexes. Nucleic Acids Res 2018; 46:8848-8864. [PMID: 29992232 PMCID: PMC6158500 DOI: 10.1093/nar/gky595] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 06/19/2018] [Accepted: 06/21/2018] [Indexed: 12/15/2022] Open
Abstract
Polycomb group (PcG) and Trithorax group (TrxG) proteins are essential for maintaining epigenetic memory in both embryonic stem cells and differentiated cells. To date, how they are localized to hundreds of specific target genes within a vertebrate genome had remained elusive. Here, by focusing on short cis-acting DNA elements of single functions, we discovered three classes of response elements in human genome: Polycomb response elements (PREs), Trithorax response elements (TREs) and Polycomb/Trithorax response elements (P/TREs). In particular, the four PREs (PRE14, 29, 39 and 48) are the first set of, to our knowledge, bona fide vertebrate PREs ever discovered, while many previously reported Drosophila or vertebrate PREs are likely P/TREs. We further demonstrated that YY1 and CpG islands are specifically enriched in the four TREs (PRE30, 41, 44 and 55), but not in the PREs. The three classes of response elements as unraveled in this study should guide further global investigation and open new doors for a deeper understanding of PcG and TrxG mechanisms in vertebrates.
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Affiliation(s)
- Junqing Du
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - Brian Kirk
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - Jia Zeng
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - Jianpeng Ma
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
- Department of Bioengineering, Rice University, 6500 Main Street, Houston, TX 77030, USA
| | - Qinghua Wang
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
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53
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Montefiori LE, Sobreira DR, Sakabe NJ, Aneas I, Joslin AC, Hansen GT, Bozek G, Moskowitz IP, McNally EM, Nóbrega MA. A promoter interaction map for cardiovascular disease genetics. eLife 2018; 7:e35788. [PMID: 29988018 PMCID: PMC6053306 DOI: 10.7554/elife.35788] [Citation(s) in RCA: 91] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 06/21/2018] [Indexed: 12/17/2022] Open
Abstract
Over 500 genetic loci have been associated with risk of cardiovascular diseases (CVDs); however, most loci are located in gene-distal non-coding regions and their target genes are not known. Here, we generated high-resolution promoter capture Hi-C (PCHi-C) maps in human induced pluripotent stem cells (iPSCs) and iPSC-derived cardiomyocytes (CMs) to provide a resource for identifying and prioritizing the functional targets of CVD associations. We validate these maps by demonstrating that promoters preferentially contact distal sequences enriched for tissue-specific transcription factor motifs and are enriched for chromatin marks that correlate with dynamic changes in gene expression. Using the CM PCHi-C map, we linked 1999 CVD-associated SNPs to 347 target genes. Remarkably, more than 90% of SNP-target gene interactions did not involve the nearest gene, while 40% of SNPs interacted with at least two genes, demonstrating the importance of considering long-range chromatin interactions when interpreting functional targets of disease loci.
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Affiliation(s)
| | - Debora R Sobreira
- Department of Human GeneticsThe University of ChicagoChicagoUnited States
| | - Noboru J Sakabe
- Department of Human GeneticsThe University of ChicagoChicagoUnited States
| | - Ivy Aneas
- Department of Human GeneticsThe University of ChicagoChicagoUnited States
| | - Amelia C Joslin
- Department of Human GeneticsThe University of ChicagoChicagoUnited States
| | - Grace T Hansen
- Department of Human GeneticsThe University of ChicagoChicagoUnited States
| | - Grazyna Bozek
- Department of Human GeneticsThe University of ChicagoChicagoUnited States
| | - Ivan P Moskowitz
- Department of Human GeneticsThe University of ChicagoChicagoUnited States
- Department of Pediatrics and PathologyThe University of ChicagoChicagoUnited States
| | - Elizabeth M McNally
- Center for Genetic MedicineNorthwestern University Feinberg School of MedicineChicagoUnited States
| | - Marcelo A Nóbrega
- Department of Human GeneticsThe University of ChicagoChicagoUnited States
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Khan S, Iqbal M, Tariq M, Baig SM, Abbas W. Epigenetic regulation of HIV-1 latency: focus on polycomb group (PcG) proteins. Clin Epigenetics 2018; 10:14. [PMID: 29441145 PMCID: PMC5800276 DOI: 10.1186/s13148-018-0441-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Accepted: 01/05/2018] [Indexed: 01/10/2023] Open
Abstract
HIV-1 latency allows the virus to persist until reactivation, in a transcriptionally silent form in its cellular reservoirs despite the presence of effective cART. Such viral persistence represents a major barrier to HIV eradication since treatment interruption leads to rebound plasma viremia. Polycomb group (PcG) proteins have recently got a considerable attention in regulating HIV-1 post-integration latency as they are involved in the repression of proviral gene expression through the methylation of histones. This epigenetic regulation plays an important role in the establishment and maintenance of HIV-1 latency. In fact, PcG proteins act in complexes and modulate the epigenetic signatures of integrated HIV-1 promoter. Key role played by PcG proteins in the molecular control of HIV-1 latency has led to hypothesize that PcG proteins may represent a valuable target for future HIV-1 therapy in purging HIV-1 reservoirs. In this regard, various small molecules have been synthesized or explored to specifically block the epigenetic activity of PcG. In this review, we will highlight the possible therapeutic approaches to achieve either a functional or sterilizing cure of HIV-1 infection with special focus on histone methylation by PcG proteins together with current and novel pharmacological approaches to reactivate HIV-1 from latency that could ultimately lead towards a better clearance of viral latent reservoirs.
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Affiliation(s)
- Sheraz Khan
- Health Biotechnology Division (HBD), National Institute for Biotechnology and Genetic Engineering (NIBGE), PO Box 577, Jhang road, Faisalabad, 38000 Pakistan
- Pakistan Institute of Engineering and Applied Sciences (PIEAS), Nilore, Islamabad, Pakistan
| | - Mazhar Iqbal
- Health Biotechnology Division (HBD), National Institute for Biotechnology and Genetic Engineering (NIBGE), PO Box 577, Jhang road, Faisalabad, 38000 Pakistan
- Pakistan Institute of Engineering and Applied Sciences (PIEAS), Nilore, Islamabad, Pakistan
| | - Muhammad Tariq
- Department of Biology (Epigenetics group), SBA School of Science and Engineering, LUMS, Lahore, 54792 Pakistan
| | - Shahid M. Baig
- Health Biotechnology Division (HBD), National Institute for Biotechnology and Genetic Engineering (NIBGE), PO Box 577, Jhang road, Faisalabad, 38000 Pakistan
- Pakistan Institute of Engineering and Applied Sciences (PIEAS), Nilore, Islamabad, Pakistan
| | - Wasim Abbas
- Health Biotechnology Division (HBD), National Institute for Biotechnology and Genetic Engineering (NIBGE), PO Box 577, Jhang road, Faisalabad, 38000 Pakistan
- Pakistan Institute of Engineering and Applied Sciences (PIEAS), Nilore, Islamabad, Pakistan
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Beira JV, Torres J, Paro R. Signalling crosstalk during early tumorigenesis in the absence of Polycomb silencing. PLoS Genet 2018; 14:e1007187. [PMID: 29357360 PMCID: PMC5794193 DOI: 10.1371/journal.pgen.1007187] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Revised: 02/01/2018] [Accepted: 01/04/2018] [Indexed: 12/19/2022] Open
Abstract
In response to stress and injury a coordinated activation of conserved signalling modules, such as JNK and JAK/STAT, is critical to trigger regenerative tissue restoration. While these pathways rebuild homeostasis and promote faithful organ recovery, it is intriguing that they also become activated in various tumour conditions. Therefore, it is crucial to understand how similar pathways can achieve context-dependent functional outputs, likely depending on cellular states. Compromised chromatin regulation, upon removal of the Polycomb group member polyhomeotic, leads to tumour formation with ectopic activation of JNK signalling, mediated by egr/grnd, in addition to JAK/STAT and Notch. Employing quantitative analyses, we show that blocking ectopic signalling impairs ph tumour growth. Furthermore, JAK/STAT functions in parallel to JNK, while Notch relies on JNK. Here, we reveal a signalling hierarchy in ph tumours that is distinct from the regenerative processes regulated by these pathways. Absence of ph renders a permissive state for expression of target genes, but our results suggest that both loss of repression and the presence of activators may collectively regulate gene expression during tumorigenesis. Further dissecting the effect of signalling, developmental or stress-induced factors will thus elucidate the regulation of physiological responses and the contribution of context-specific cellular states.
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Affiliation(s)
- Jorge V. Beira
- ETH Zürich, Department of Biosystems Science and Engineering, MattenstrasseBasel, Switzerland
- * E-mail: (JVB); (RP)
| | - Joana Torres
- ETH Zürich, Department of Biosystems Science and Engineering, MattenstrasseBasel, Switzerland
| | - Renato Paro
- ETH Zürich, Department of Biosystems Science and Engineering, MattenstrasseBasel, Switzerland
- Faculty of Science, University of Basel, KlingelbergstrasseBasel, Switzerland
- * E-mail: (JVB); (RP)
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56
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Li IMH, Liu K, Neal A, Clegg PD, De Val S, Bou-Gharios G. Differential tissue specific, temporal and spatial expression patterns of the Aggrecan gene is modulated by independent enhancer elements. Sci Rep 2018; 8:950. [PMID: 29343853 PMCID: PMC5772622 DOI: 10.1038/s41598-018-19186-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 12/22/2017] [Indexed: 02/06/2023] Open
Abstract
The transcriptional mechanism through which chondrocytes control the spatial and temporal composition of the cartilage tissue has remained largely elusive. The central aim of this study was to identify whether transcriptional enhancers played a role in the organisation of the chondrocytes in cartilaginous tissue. We focused on the Aggrecan gene (Acan) as it is essential for the normal structure and function of cartilage and it is expressed developmentally in different stages of chondrocyte maturation. Using transgenic reporter studies in mice we identified four elements, two of which showed individual chondrocyte developmental stage specificity. In particular, one enhancer (-80) distinguishes itself from the others by being predominantly active in adult cartilage. Furthermore, the -62 element uniquely drove reporter activity in early chondrocytes. The remaining chondrocyte specific enhancers, +28 and -30, showed no preference to chondrocyte type. The transcription factor SOX9 interacted with all the enhancers in vitro and mutation of SOX9 binding sites in one of the enhancers (-30) resulted in a loss of its chondrocyte specificity and ectopic enhancer reporter activity. Thus, the Acan enhancers orchestrate the precise spatiotemporal expression of this gene in cartilage types at different stages of development and adulthood.
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Affiliation(s)
- Ian M H Li
- Institute of Ageing and Chronic Disease, University of Liverpool, William Henry Duncan Building, Liverpool, L7 8TX, UK
| | - Ke Liu
- Institute of Ageing and Chronic Disease, University of Liverpool, William Henry Duncan Building, Liverpool, L7 8TX, UK
| | - Alice Neal
- Ludwig Cancer Research Ltd, University of Oxford, Oxford, UK
| | - Peter D Clegg
- Institute of Ageing and Chronic Disease, University of Liverpool, William Henry Duncan Building, Liverpool, L7 8TX, UK
| | - Sarah De Val
- Ludwig Cancer Research Ltd, University of Oxford, Oxford, UK
| | - George Bou-Gharios
- Institute of Ageing and Chronic Disease, University of Liverpool, William Henry Duncan Building, Liverpool, L7 8TX, UK.
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57
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58
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Saxena M, Roman AKS, O'Neill NK, Sulahian R, Jadhav U, Shivdasani RA. Transcription factor-dependent 'anti-repressive' mammalian enhancers exclude H3K27me3 from extended genomic domains. Genes Dev 2018; 31:2391-2404. [PMID: 29321178 PMCID: PMC5795785 DOI: 10.1101/gad.308536.117] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Accepted: 12/08/2017] [Indexed: 11/25/2022]
Abstract
Compacted chromatin and nucleosomes are known barriers to gene expression; the nature and relative importance of other transcriptional constraints remain unclear, especially at distant enhancers. Polycomb repressor complex 2 (PRC2) places the histone mark H3K27me3 predominantly at promoters, where its silencing activity is well documented. In adult tissues, enhancers lack H3K27me3, and it is unknown whether intergenic H3K27me3 deposits affect nearby genes. In primary intestinal villus cells, we identified hundreds of tissue-restricted enhancers that require the transcription factor (TF) CDX2 to prevent the incursion of H3K27me3 from adjoining areas of elevated basal marking into large well-demarcated genome domains. Similarly, GATA1-dependent enhancers exclude H3K27me3 from extended regions in erythroid blood cells. Excess intergenic H3K27me3 in both TF-deficient tissues is associated with extreme mRNA deficits, which are significantly rescued in intestinal cells lacking PRC2. Explaining these observations, enhancers show TF-dependent binding of the H3K27 demethylase KDM6A. Thus, in diverse cell types, certain genome regions far from promoters accumulate H3K27me3, and optimal gene expression depends on enhancers clearing this repressive mark. These findings reveal new "anti-repressive" function for hundreds of tissue-specific enhancers.
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Affiliation(s)
- Madhurima Saxena
- Department of Medical Oncology, Center for Functional Cancer Epigenetics, Dana-Farber Cancer Institute, Boston, Massachusetts 02215, USA.,Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02215, USA
| | - Adrianna K San Roman
- Department of Medical Oncology, Center for Functional Cancer Epigenetics, Dana-Farber Cancer Institute, Boston, Massachusetts 02215, USA.,Program in Biological and Biomedical Sciences, Harvard Medical School, Boston, Massachusetts 02215, USA
| | - Nicholas K O'Neill
- Department of Medical Oncology, Center for Functional Cancer Epigenetics, Dana-Farber Cancer Institute, Boston, Massachusetts 02215, USA
| | - Rita Sulahian
- Department of Medical Oncology, Center for Functional Cancer Epigenetics, Dana-Farber Cancer Institute, Boston, Massachusetts 02215, USA.,Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02215, USA
| | - Unmesh Jadhav
- Department of Medical Oncology, Center for Functional Cancer Epigenetics, Dana-Farber Cancer Institute, Boston, Massachusetts 02215, USA.,Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02215, USA
| | - Ramesh A Shivdasani
- Department of Medical Oncology, Center for Functional Cancer Epigenetics, Dana-Farber Cancer Institute, Boston, Massachusetts 02215, USA.,Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02215, USA.,Harvard Stem Cell Institute, Cambridge, Massachusetts 02139, USA
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59
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Abstract
This Perspective discusses a recent study by Erceg et al. (2017) regarding regulated gene silencing by Polycomb group (PcG) proteins. It focuses on characterizing Polycomb response elements (PREs) and their dual functions in Drosophila. Development requires the expression of master regulatory genes necessary to specify a cell lineage. Equally significant is the stable and heritable silencing of master regulators that would specify alternative lineages. This regulated gene silencing is carried out by Polycomb group (PcG) proteins, which must be correctly recruited only to the subset of their target loci that requires lineage-specific silencing. A recent study by Erceg and colleagues (pp. 590–602) expands on a key aspect of that targeting: The same DNA elements that recruit PcG complexes to a repressed locus also encode transcriptional enhancers that function in different lineages where that locus must be expressed. Thus, PcG targeting elements overlap with enhancers.
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Affiliation(s)
- Elizabeth S Jaensch
- Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts, 02114, USA
| | - Sharmistha Kundu
- Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts, 02114, USA
| | - Robert E Kingston
- Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts, 02114, USA
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60
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Schuettengruber B, Bourbon HM, Di Croce L, Cavalli G. Genome Regulation by Polycomb and Trithorax: 70 Years and Counting. Cell 2017; 171:34-57. [DOI: 10.1016/j.cell.2017.08.002] [Citation(s) in RCA: 611] [Impact Index Per Article: 87.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Revised: 07/17/2017] [Accepted: 08/01/2017] [Indexed: 01/05/2023]
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