101
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Ridenour JB, Möller M, Freitag M. Polycomb Repression without Bristles: Facultative Heterochromatin and Genome Stability in Fungi. Genes (Basel) 2020; 11:E638. [PMID: 32527036 PMCID: PMC7348808 DOI: 10.3390/genes11060638] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 05/27/2020] [Accepted: 06/04/2020] [Indexed: 02/06/2023] Open
Abstract
Genome integrity is essential to maintain cellular function and viability. Consequently, genome instability is frequently associated with dysfunction in cells and associated with plant, animal, and human diseases. One consequence of relaxed genome maintenance that may be less appreciated is an increased potential for rapid adaptation to changing environments in all organisms. Here, we discuss evidence for the control and function of facultative heterochromatin, which is delineated by methylation of histone H3 lysine 27 (H3K27me) in many fungi. Aside from its relatively well understood role in transcriptional repression, accumulating evidence suggests that H3K27 methylation has an important role in controlling the balance between maintenance and generation of novelty in fungal genomes. We present a working model for a minimal repressive network mediated by H3K27 methylation in fungi and outline challenges for future research.
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Affiliation(s)
| | | | - Michael Freitag
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis OR 97331, USA; (J.B.R.); (M.M.)
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102
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Basta JM, Singh AP, Robbins L, Stout L, Pherson M, Rauchman M. The core SWI/SNF catalytic subunit Brg1 regulates nephron progenitor cell proliferation and differentiation. Dev Biol 2020; 464:176-187. [PMID: 32504627 DOI: 10.1016/j.ydbio.2020.05.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 05/11/2020] [Accepted: 05/12/2020] [Indexed: 01/09/2023]
Abstract
Chromatin-remodeling complexes play critical roles in establishing gene expression patterns in response to developmental signals. How these epigenetic regulators determine the fate of progenitor cells during development of specific organs is not well understood. We found that genetic deletion of Brg1 (Smarca4), the core enzymatic protein in SWI/SNF, in nephron progenitor cells leads to severe renal hypoplasia. Nephron progenitor cells were depleted in Six2-Cre, Brg1flx/flx mice due to reduced cell proliferation. This defect in self-renewal, together with impaired differentiation resulted in a profound nephron deficit in Brg1 mutant kidneys. Sall1, a transcription factor that is required for expansion and maintenance of nephron progenitors, associates with SWI/SNF. Brg1 and Sall1 bind promoters of many progenitor cell genes and regulate expression of key targets that promote their proliferation.
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Affiliation(s)
- Jeannine M Basta
- John T. Milliken Department of Medicine, Division of Nephrology, Washington University School of Medicine, St. Louis, Mo 63110 USA
| | - Ajeet P Singh
- Division of Pediatric Hematology/Oncology, Departement of Pediatrics and Department of Biochemistry & Molecular Biology, Pennsylvania State University, Hershey, PA 17033 USA
| | - Lynn Robbins
- John T. Milliken Department of Medicine, Division of Nephrology, Washington University School of Medicine, St. Louis, Mo 63110 USA; VA St. Louis Health Care System, John Cochran Division, St. Louis, MO, 63106, USA
| | - Lisa Stout
- John T. Milliken Department of Medicine, Division of Nephrology, Washington University School of Medicine, St. Louis, Mo 63110 USA
| | - Michelle Pherson
- Department of Biochemistry & Molecular Biology, Saint Louis University, St. Louis, MO 63104 USA
| | - Michael Rauchman
- John T. Milliken Department of Medicine, Division of Nephrology, Washington University School of Medicine, St. Louis, Mo 63110 USA; VA St. Louis Health Care System, John Cochran Division, St. Louis, MO, 63106, USA; Deaprtememt of Developmental Biology, Washington University School of Medicine, St. Louis, MO 63110 USA.
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103
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Hu B, Lin JZ, Yang XB, Sang XT. The roles of mutated SWI/SNF complexes in the initiation and development of hepatocellular carcinoma and its regulatory effect on the immune system: A review. Cell Prolif 2020; 53:e12791. [PMID: 32162380 PMCID: PMC7162795 DOI: 10.1111/cpr.12791] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 02/13/2020] [Accepted: 02/22/2020] [Indexed: 12/11/2022] Open
Abstract
Hepatocellular carcinoma (HCC) is a primary liver malignancy with a high global prevalence and a dismal prognosis. Studies are urgently needed to examine the molecular pathogenesis and biological characteristics of HCC. Chromatin remodelling, an integral component of the DNA damage response, protects against DNA damage‐induced genome instability and tumorigenesis by triggering the signalling events that activate the interconnected DNA repair pathways. The SWI/SNF complexes are one of the most extensively investigated adenosine triphosphate‐dependent chromatin remodelling complexes, and mutations in genes encoding SWI/SNF subunits are frequently observed in various human cancers, including HCC. The mutated SWI/SNF complex subunits exert dual functions by accelerating or inhibiting HCC initiation and progression. Furthermore, the abnormal SWI/SNF complexes influence the transcription of interferon‐stimulated genes, as well as the differentiation, activation and recruitment of several immune cell types. In addition, they exhibit synergistic effects with immune checkpoint inhibitors in the treatment of diverse tumour types. Therefore, understanding the mutations and deficiencies of the SMI/SNF complexes, together with the associated functional mechanisms, may provide a novel strategy to treat HCC through targeting the related genes or modulating the tumour microenvironment.
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Affiliation(s)
- Bo Hu
- Department of Liver Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Jian-Zhen Lin
- Department of Liver Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Xiao-Bo Yang
- Department of Liver Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Xin-Ting Sang
- Department of Liver Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
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104
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Chan SCL, Zhang Y. PAC1-ing up the epigenetic landscape. Nat Immunol 2020; 21:247-248. [PMID: 31969720 DOI: 10.1038/s41590-020-0594-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Sze Chun Leo Chan
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.,Immunology Programme, the Life Science Institute, National University of Singapore, Singapore, Singapore
| | - Yongliang Zhang
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore. .,Immunology Programme, the Life Science Institute, National University of Singapore, Singapore, Singapore.
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105
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Epigenome Regulation by Dynamic Nucleosome Unwrapping. Trends Biochem Sci 2020; 45:13-26. [PMID: 31630896 PMCID: PMC10168609 DOI: 10.1016/j.tibs.2019.09.003] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 09/09/2019] [Accepted: 09/13/2019] [Indexed: 12/12/2022]
Abstract
Gene regulation in eukaryotes requires the controlled access of sequence-specific transcription factors (TFs) to their sites in a chromatin landscape dominated by nucleosomes. Nucleosomes are refractory to TF binding, and often must be removed from regulatory regions. Recent genomic studies together with in vitro measurements suggest that the nucleosome barrier to TF binding is modulated by dynamic nucleosome unwrapping governed by ATP-dependent chromatin remodelers. Genome-wide occupancy and the regulation of subnucleosomal intermediates have gained recent attention with the application of high-resolution approaches for precision mapping of protein-DNA interactions. We summarize here recent findings on nucleosome substructures and TF binding dynamics, and highlight how unwrapped nucleosomal intermediates provide a novel signature of active chromatin.
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106
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Hasan N, Ahuja N. The Emerging Roles of ATP-Dependent Chromatin Remodeling Complexes in Pancreatic Cancer. Cancers (Basel) 2019; 11:E1859. [PMID: 31769422 PMCID: PMC6966483 DOI: 10.3390/cancers11121859] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 11/19/2019] [Accepted: 11/20/2019] [Indexed: 02/08/2023] Open
Abstract
Pancreatic cancer is an aggressive cancer with low survival rates. Genetic and epigenetic dysregulation has been associated with the initiation and progression of pancreatic tumors. Multiple studies have pointed to the involvement of aberrant chromatin modifications in driving tumor behavior. ATP-dependent chromatin remodeling complexes regulate chromatin structure and have critical roles in stem cell maintenance, development, and cancer. Frequent mutations and chromosomal aberrations in the genes associated with subunits of the ATP-dependent chromatin remodeling complexes have been detected in different cancer types. In this review, we summarize the current literature on the genomic alterations and mechanistic studies of the ATP-dependent chromatin remodeling complexes in pancreatic cancer. Our review is focused on the four main subfamilies: SWItch/sucrose non-fermentable (SWI/SNF), imitation SWI (ISWI), chromodomain-helicase DNA-binding protein (CHD), and INOsitol-requiring mutant 80 (INO80). Finally, we discuss potential novel treatment options that use small molecules to target these complexes.
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Affiliation(s)
| | - Nita Ahuja
- Department of Surgery, Yale University School of Medicine, New Haven, CT 06520, USA;
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107
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Zhang W, Ge H, Jiang Y, Huang R, Wu Y, Wang D, Guo S, Li S, Wang Y, Jiang H, Cheng J. Combinational therapeutic targeting of BRD4 and CDK7 synergistically induces anticancer effects in head and neck squamous cell carcinoma. Cancer Lett 2019; 469:510-523. [PMID: 31765738 DOI: 10.1016/j.canlet.2019.11.027] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 10/15/2019] [Accepted: 11/18/2019] [Indexed: 12/27/2022]
Abstract
The bromodomain and extra-terminal domain protein BRD4 has been recognized as a key oncogenic driver and a druggable target against cancer. However, these BRD4 inhibitors as monotherapy were moderate in efficacy in preclinical models. Here we utilized a small-scale drug synergy screen that combined the BRD4 inhibitor (JQ1) with 8 epigenetic or transcriptional targeted chemicals and identified THZ1 (a CDK7 inhibitor) acting synergistically with JQ1 against head neck squamous cell carcinoma (HNSCC). Combinational JQ1 and THZ1 treatment impaired cell proliferation, induced apoptosis and senescence, which were largely recapitulated by dual BRD4 and CDK7 knockdown. Combinational treatment inhibited tumor growth and progression in 4NQO-induced HNSCC and xenograft animal models. RNA-sequencing analyses identified hundreds of differentially expressed genes modulated by JQ1 and THZ1, which were significantly enriched in categories including cell cycle and apoptosis. Mechanistically, combinational treatment reduced H3K27ac enrichment in the super-enhancer region of YAP1, which inactivated its transcription and in turn induced anti-proliferative and pro-apoptotic effects. Combined BRD4 and CDK7 upregulation associated with worst prognosis in HNSCC patients. Collectively, our findings reveal a novel therapeutic strategy of pharmacological inhibitions of BRD4 and CDK7 against HNSCC.
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Affiliation(s)
- Wei Zhang
- Jiangsu Key Laboratory of Oral Disease, Nanjing Medical University, Jiangsu, 210029, People's Republic of China; Department of Oral and Maxillofacial Surgery, Affiliated Stomatological Hospital, Nanjing Medical University, Nanjing, 210029, People's Republic of China
| | - Han Ge
- Jiangsu Key Laboratory of Oral Disease, Nanjing Medical University, Jiangsu, 210029, People's Republic of China; Department of Oral and Maxillofacial Surgery, Affiliated Stomatological Hospital, Nanjing Medical University, Nanjing, 210029, People's Republic of China
| | - Yue Jiang
- Jiangsu Key Laboratory of Oral Disease, Nanjing Medical University, Jiangsu, 210029, People's Republic of China
| | - Rong Huang
- Jiangsu Key Laboratory of Oral Disease, Nanjing Medical University, Jiangsu, 210029, People's Republic of China
| | - Yaping Wu
- Jiangsu Key Laboratory of Oral Disease, Nanjing Medical University, Jiangsu, 210029, People's Republic of China
| | - Dongmiao Wang
- Jiangsu Key Laboratory of Oral Disease, Nanjing Medical University, Jiangsu, 210029, People's Republic of China
| | - Songsong Guo
- Department of Oral and Maxillofacial Surgery, Affiliated Stomatological Hospital, Nanjing Medical University, Nanjing, 210029, People's Republic of China
| | - Sheng Li
- Department of Oral and Maxillofacial Surgery, Affiliated Stomatological Hospital, Nanjing Medical University, Nanjing, 210029, People's Republic of China
| | - Yanling Wang
- Jiangsu Key Laboratory of Oral Disease, Nanjing Medical University, Jiangsu, 210029, People's Republic of China
| | - Hongbing Jiang
- Department of Oral and Maxillofacial Surgery, Affiliated Stomatological Hospital, Nanjing Medical University, Nanjing, 210029, People's Republic of China
| | - Jie Cheng
- Jiangsu Key Laboratory of Oral Disease, Nanjing Medical University, Jiangsu, 210029, People's Republic of China; Department of Oral and Maxillofacial Surgery, Affiliated Stomatological Hospital, Nanjing Medical University, Nanjing, 210029, People's Republic of China.
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108
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Abstract
Polycomb repressive complex 2 (PRC2) is a conserved chromatin regulator that is responsible for the methylation of histone H3 lysine 27 (H3K27). PRC2 is essential for normal development and its loss of function thus results in a range of developmental phenotypes. Here, we review the latest advances in our understanding of mammalian PRC2 activity and present an updated summary of the phenotypes associated with its loss of function in mice. We then discuss recent studies that have highlighted regulatory interplay between the modifications laid down by PRC2 and other chromatin modifiers, including NSD1 and DNMT3A. Finally, we propose a model in which the dysregulation of these modifications at intergenic regions is a shared molecular feature of genetically distinct but highly phenotypically similar overgrowth syndromes in humans.
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Affiliation(s)
- Orla Deevy
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland
| | - Adrian P Bracken
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland
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109
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Chabanon RM, Morel D, Postel-Vinay S. Exploiting epigenetic vulnerabilities in solid tumors: Novel therapeutic opportunities in the treatment of SWI/SNF-defective cancers. Semin Cancer Biol 2019; 61:180-198. [PMID: 31568814 DOI: 10.1016/j.semcancer.2019.09.018] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Revised: 09/23/2019] [Accepted: 09/24/2019] [Indexed: 12/12/2022]
Abstract
Mammalian switch/sucrose non-fermentable (mSWI/SNF) family complexes are pivotal elements of the chromatin remodeling machinery, which contribute to the regulation of several major cellular functions. Large-scale exome-wide sequencing studies have identified mutations in genes encoding mSWI/SNF subunits in 20% of all human cancers, establishing mSWI/SNF deficiency as a recurrent oncogenic alteration. Accumulating evidence now supports that several mSWI/SNF defects represent targetable vulnerabilities in cancer; notably, recent research advances have unveiled unexpected synthetic lethal opportunities that foster the development of novel biomarker-driven and mechanism-based therapeutic approaches for the treatment of mSWI/SNF-deficient tumors. Here, we review the latest breakthroughs and discoveries that inform our understanding of the mSWI/SNF complexes biology in carcinogenesis, and discuss the most promising therapeutic strategies to target mSWI/SNF defects in human solid malignancies.
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Affiliation(s)
- Roman M Chabanon
- Université Paris Saclay, Université Paris-Sud, Faculté de médicine, Le Kremlin Bicêtre, France; ATIP-Avenir Group, Inserm Unit U981, Gustave Roussy, Villejuif, France; The Breast Cancer Now Toby Robins Breast Cancer Research Centre, France; CRUK Gene Function Laboratory, The Institute of Cancer Research, London, United Kingdom
| | - Daphné Morel
- Université Paris Saclay, Université Paris-Sud, Faculté de médicine, Le Kremlin Bicêtre, France; ATIP-Avenir Group, Inserm Unit U981, Gustave Roussy, Villejuif, France
| | - Sophie Postel-Vinay
- Université Paris Saclay, Université Paris-Sud, Faculté de médicine, Le Kremlin Bicêtre, France; ATIP-Avenir Group, Inserm Unit U981, Gustave Roussy, Villejuif, France; DITEP (Département d'Innovations Thérapeutiques et Essais Précoces), Gustave Roussy, Villejuif, France.
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110
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The Epigenetics of Aging in Invertebrates. Int J Mol Sci 2019; 20:ijms20184535. [PMID: 31540238 PMCID: PMC6769462 DOI: 10.3390/ijms20184535] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 09/03/2019] [Accepted: 09/12/2019] [Indexed: 12/16/2022] Open
Abstract
Aging is an unstoppable process coupled to the loss of physiological function and increased susceptibility to diseases. Epigenetic alteration is one of the hallmarks of aging, which involves changes in DNA methylation patterns, post-translational modification of histones, chromatin remodeling and non-coding RNA interference. Invertebrate model organisms, such as Drosophila melanogaster and Caenorhabditis elegans, have been used to investigate the biological mechanisms of aging because they show, evolutionarily, the conservation of many aspects of aging. In this review, we focus on recent advances in the epigenetic changes of aging with invertebrate models, providing insight into the relationship between epigenetic dynamics and aging.
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111
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Healy E, Mucha M, Glancy E, Fitzpatrick DJ, Conway E, Neikes HK, Monger C, Van Mierlo G, Baltissen MP, Koseki Y, Vermeulen M, Koseki H, Bracken AP. PRC2.1 and PRC2.2 Synergize to Coordinate H3K27 Trimethylation. Mol Cell 2019; 76:437-452.e6. [PMID: 31521505 DOI: 10.1016/j.molcel.2019.08.012] [Citation(s) in RCA: 118] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 06/28/2019] [Accepted: 08/12/2019] [Indexed: 12/12/2022]
Abstract
Polycomb repressive complex 2 (PRC2) is composed of EED, SUZ12, and EZH1/2 and mediates mono-, di-, and trimethylation of histone H3 at lysine 27. At least two independent subcomplexes exist, defined by their specific accessory proteins: PRC2.1 (PCL1-3, EPOP, and PALI1/2) and PRC2.2 (AEBP2 and JARID2). We show that PRC2.1 and PRC2.2 share the majority of target genes in mouse embryonic stem cells. The loss of PCL1-3 is sufficient to evict PRC2.1 from Polycomb target genes but only leads to a partial reduction of PRC2.2 and H3K27me3. Conversely, disruption of PRC2.2 function through the loss of either JARID2 or RING1A/B is insufficient to completely disrupt targeting of SUZ12 by PCLs. Instead, the combined loss of both PRC2.1 and PRC2.2 is required, leading to the global mislocalization of SUZ12. This supports a model in which the specific accessory proteins within PRC2.1 and PRC2.2 cooperate to direct H3K27me3 via both synergistic and independent mechanisms.
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Affiliation(s)
- Evan Healy
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland
| | - Marlena Mucha
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland
| | - Eleanor Glancy
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland
| | | | - Eric Conway
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland
| | - Hannah K Neikes
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland
| | - Craig Monger
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland
| | - Guido Van Mierlo
- Department of Molecular Biology, Faculty of Science, Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen, Nijmegen, the Netherlands
| | - Marijke P Baltissen
- Department of Molecular Biology, Faculty of Science, Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen, Nijmegen, the Netherlands
| | - Yoko Koseki
- Laboratory for Developmental Genetics, RIKEN Center for Integrative Medical Sciences (IMS), Yokohama, Japan
| | - Michiel Vermeulen
- Department of Molecular Biology, Faculty of Science, Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen, Nijmegen, the Netherlands
| | - Haruhiko Koseki
- Laboratory for Developmental Genetics, RIKEN Center for Integrative Medical Sciences (IMS), Yokohama, Japan
| | - Adrian P Bracken
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland.
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