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Kerr L, Kafetzopoulos I, Grima R, Sproul D. Genome-wide single-molecule analysis of long-read DNA methylation reveals heterogeneous patterns at heterochromatin that reflect nucleosome organisation. PLoS Genet 2023; 19:e1010958. [PMID: 37782664 PMCID: PMC10569558 DOI: 10.1371/journal.pgen.1010958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 10/12/2023] [Accepted: 09/04/2023] [Indexed: 10/04/2023] Open
Abstract
High-throughput sequencing technology is central to our current understanding of the human methylome. The vast majority of studies use chemical conversion to analyse bulk-level patterns of DNA methylation across the genome from a population of cells. While this technology has been used to probe single-molecule methylation patterns, such analyses are limited to short reads of a few hundred basepairs. DNA methylation can also be directly detected using Nanopore sequencing which can generate reads measuring megabases in length. However, thus far these analyses have largely focused on bulk-level assessment of DNA methylation. Here, we analyse DNA methylation in single Nanopore reads from human lymphoblastoid cells, to show that bulk-level metrics underestimate large-scale heterogeneity in the methylome. We use the correlation in methylation state between neighbouring sites to quantify single-molecule heterogeneity and find that heterogeneity varies significantly across the human genome, with some regions having heterogeneous methylation patterns at the single-molecule level and others possessing more homogeneous methylation patterns. By comparing the genomic distribution of the correlation to epigenomic annotations, we find that the greatest heterogeneity in single-molecule patterns is observed within heterochromatic partially methylated domains (PMDs). In contrast, reads originating from euchromatic regions and gene bodies have more ordered DNA methylation patterns. By analysing the patterns of single molecules in more detail, we show the existence of a nucleosome-scale periodicity in DNA methylation that accounts for some of the heterogeneity we uncover in long single-molecule DNA methylation patterns. We find that this periodic structure is partially masked in bulk data and correlates with DNA accessibility as measured by nanoNOMe-seq, suggesting that it could be generated by nucleosomes. Our findings demonstrate the power of single-molecule analysis of long-read data to understand the structure of the human methylome.
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Affiliation(s)
- Lyndsay Kerr
- MRC Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, United Kingdom
| | - Ioannis Kafetzopoulos
- MRC Human Genetics Unit and CRUK Edinburgh Centre, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, United Kingdom
- Current address: Altos Labs Cambridge Institute, Cambridge, United Kingdom
| | - Ramon Grima
- School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Duncan Sproul
- MRC Human Genetics Unit and CRUK Edinburgh Centre, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, United Kingdom
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2
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Weigert R, Hetzel S, Bailly N, Haggerty C, Ilik IA, Yung PYK, Navarro C, Bolondi A, Kumar AS, Anania C, Brändl B, Meierhofer D, Lupiáñez DG, Müller FJ, Aktas T, Elsässer SJ, Kretzmer H, Smith ZD, Meissner A. Dynamic antagonism between key repressive pathways maintains the placental epigenome. Nat Cell Biol 2023; 25:579-591. [PMID: 37024684 PMCID: PMC10104784 DOI: 10.1038/s41556-023-01114-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 02/21/2023] [Indexed: 04/08/2023]
Abstract
DNA and Histone 3 Lysine 27 methylation typically function as repressive modifications and operate within distinct genomic compartments. In mammals, the majority of the genome is kept in a DNA methylated state, whereas the Polycomb repressive complexes regulate the unmethylated CpG-rich promoters of developmental genes. In contrast to this general framework, the extra-embryonic lineages display non-canonical, globally intermediate DNA methylation levels, including disruption of local Polycomb domains. Here, to better understand this unusual landscape's molecular properties, we genetically and chemically perturbed major epigenetic pathways in mouse trophoblast stem cells. We find that the extra-embryonic epigenome reflects ongoing and dynamic de novo methyltransferase recruitment, which is continuously antagonized by Polycomb to maintain intermediate, locally disordered methylation. Despite its disorganized molecular appearance, our data point to a highly controlled equilibrium between counteracting repressors within extra-embryonic cells, one that can seemingly persist indefinitely without bistable features typically seen for embryonic forms of epigenetic regulation.
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Affiliation(s)
- Raha Weigert
- Department of Genome Regulation, Max Planck Institute for Molecular Genetics, Berlin, Germany
- Department of Medical Biotechnology, Technische Universität Berlin, Berlin, Germany
| | - Sara Hetzel
- Department of Genome Regulation, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Nina Bailly
- Department of Genome Regulation, Max Planck Institute for Molecular Genetics, Berlin, Germany
- Department of Biology, Chemistry and Pharmacy, Freie Universität Berlin, Berlin, Germany
| | - Chuck Haggerty
- Department of Genome Regulation, Max Planck Institute for Molecular Genetics, Berlin, Germany
- Department of Biology, Chemistry and Pharmacy, Freie Universität Berlin, Berlin, Germany
| | - Ibrahim A Ilik
- Otto Warburg Laboratories, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Philip Yuk Kwong Yung
- Science for Life Laboratory, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
- Ming Wai Lau Centre for Reparative Medicine, Stockholm node, Karolinska Institutet, Stockholm, Sweden
| | - Carmen Navarro
- Science for Life Laboratory, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
- Ming Wai Lau Centre for Reparative Medicine, Stockholm node, Karolinska Institutet, Stockholm, Sweden
| | - Adriano Bolondi
- Department of Genome Regulation, Max Planck Institute for Molecular Genetics, Berlin, Germany
- Department of Biology, Chemistry and Pharmacy, Freie Universität Berlin, Berlin, Germany
| | - Abhishek Sampath Kumar
- Department of Genome Regulation, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Chiara Anania
- Epigenetics and Sex Development Group, Berlin Institute for Medical Systems Biology, Max-Delbrück Center for Molecular Medicine, Berlin-Buch, Germany
| | - Björn Brändl
- Department of Genome Regulation, Max Planck Institute for Molecular Genetics, Berlin, Germany
- Universitätsklinikum Schleswig-Holstein Campus Kiel, Zentrum für Integrative Psychiatrie gGmbH, Kiel, Germany
| | - David Meierhofer
- Mass Spectrometry Joint Facilities Scientific Service, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Darío G Lupiáñez
- Epigenetics and Sex Development Group, Berlin Institute for Medical Systems Biology, Max-Delbrück Center for Molecular Medicine, Berlin-Buch, Germany
| | - Franz-Josef Müller
- Department of Genome Regulation, Max Planck Institute for Molecular Genetics, Berlin, Germany
- Universitätsklinikum Schleswig-Holstein Campus Kiel, Zentrum für Integrative Psychiatrie gGmbH, Kiel, Germany
| | - Tugce Aktas
- Otto Warburg Laboratories, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Simon J Elsässer
- Science for Life Laboratory, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
- Ming Wai Lau Centre for Reparative Medicine, Stockholm node, Karolinska Institutet, Stockholm, Sweden
| | - Helene Kretzmer
- Department of Genome Regulation, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Zachary D Smith
- Department of Genetics, Yale Stem Cell Center, Yale School of Medicine, New Haven, CT, USA.
| | - Alexander Meissner
- Department of Genome Regulation, Max Planck Institute for Molecular Genetics, Berlin, Germany.
- Department of Biology, Chemistry and Pharmacy, Freie Universität Berlin, Berlin, Germany.
- Broad Institute of MIT and Harvard, Cambridge, MA, USA.
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, US.
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3
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Ding Y, Cai K, Liu L, Zhang Z, Zheng X, Shi J. mHapTk: a comprehensive toolkit for the analysis of DNA methylation haplotypes. Bioinformatics 2022; 38:5141-5143. [PMID: 36179079 DOI: 10.1093/bioinformatics/btac650] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 09/22/2022] [Accepted: 09/29/2022] [Indexed: 12/24/2022] Open
Abstract
SUMMARY Bisulfite sequencing remains the gold standard technique to detect DNA methylation profiles at single-nucleotide resolution. The DNA methylation status of CpG sites on the same fragment represents a discrete methylation haplotype (mHap). The mHap-level metrics were demonstrated to be promising cancer biomarkers and explain more gene expression variation than average methylation. However, most existing tools focus on average methylation and neglect mHap patterns. Here, we present mHapTk, a comprehensive python toolkit for the analysis of DNA mHap. It calculates eight mHap-level summary statistics in predefined regions or across individual CpG in a genome-wide manner. It identifies methylation haplotype blocks, in which methylations of pairwise CpGs are tightly correlated. Furthermore, mHap patterns can be visualized with the built-in functions in mHapTk or external tools such as IGV and deepTools. AVAILABILITY AND IMPLEMENTATION https://jiantaoshi.github.io/mhaptk/index.html. SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Yi Ding
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai 200031, China
| | - Kangwen Cai
- Department of Mathematics, Shanghai Normal University, Shanghai 200234, China
| | - Leiqin Liu
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai 200031, China
| | - Zhiqiang Zhang
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai 200031, China
| | - Xiaoqi Zheng
- Center for Single-Cell Omics, School of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Jiantao Shi
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai 200031, China
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Hetzel S, Mattei AL, Kretzmer H, Qu C, Chen X, Fan Y, Wu G, Roberts KG, Luger S, Litzow M, Rowe J, Paietta E, Stock W, Mardis ER, Wilson RK, Downing JR, Mullighan CG, Meissner A. Acute lymphoblastic leukemia displays a distinct highly methylated genome. NATURE CANCER 2022; 3:768-782. [PMID: 35590059 PMCID: PMC9236905 DOI: 10.1038/s43018-022-00370-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 03/25/2022] [Indexed: 04/13/2023]
Abstract
DNA methylation is tightly regulated during development and is stably maintained in healthy cells. In contrast, cancer cells are commonly characterized by a global loss of DNA methylation co-occurring with CpG island hypermethylation. In acute lymphoblastic leukemia (ALL), the commonest childhood cancer, perturbations of CpG methylation have been reported to be associated with genetic disease subtype and outcome, but data from large cohorts at a genome-wide scale are lacking. Here, we performed whole-genome bisulfite sequencing across ALL subtypes, leukemia cell lines and healthy hematopoietic cells, and show that unlike most cancers, ALL samples exhibit CpG island hypermethylation but minimal global loss of methylation. This was most pronounced in T cell ALL and accompanied by an exceptionally broad range of hypermethylation of CpG islands between patients, which is influenced by TET2 and DNMT3B. These findings demonstrate that ALL is characterized by an unusually highly methylated genome and provide further insights into the non-canonical regulation of methylation in cancer.
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Affiliation(s)
- Sara Hetzel
- Department of Genome Regulation, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Alexandra L Mattei
- Department of Genome Regulation, Max Planck Institute for Molecular Genetics, Berlin, Germany
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, USA
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA
| | - Helene Kretzmer
- Department of Genome Regulation, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Chunxu Qu
- Department of Pathology, St Jude Children's Research Hospital, Memphis, TN, USA
| | - Xiang Chen
- Department of Computational Biology, St Jude Children's Research Hospital, Memphis, TN, USA
| | - Yiping Fan
- Center for Applied Bioinformatics, St Jude Children's Research Hospital, Memphis, TN, USA
| | - Gang Wu
- Center for Applied Bioinformatics, St Jude Children's Research Hospital, Memphis, TN, USA
| | - Kathryn G Roberts
- Department of Pathology, St Jude Children's Research Hospital, Memphis, TN, USA
| | - Selina Luger
- Abramson Cancer Center, University of Pennsylvania, Philadelphia, PA, USA
| | - Mark Litzow
- Division of Hematology, Department of Internal Medicine, Mayo Clinic, Rochester, MN, USA
| | - Jacob Rowe
- Department of Hematology, Shaare Zedek Medical Center, Jerusalem, Israel
| | | | - Wendy Stock
- University of Chicago Comprehensive Cancer Center, Chicago, IL, USA
| | - Elaine R Mardis
- Institute for Genomic Medicine, Nationwide Children's Hospital, Columbus, OH, USA
| | - Richard K Wilson
- Institute for Genomic Medicine, Nationwide Children's Hospital, Columbus, OH, USA
| | - James R Downing
- Department of Pathology, St Jude Children's Research Hospital, Memphis, TN, USA
| | - Charles G Mullighan
- Department of Pathology, St Jude Children's Research Hospital, Memphis, TN, USA.
| | - Alexander Meissner
- Department of Genome Regulation, Max Planck Institute for Molecular Genetics, Berlin, Germany.
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, USA.
- Broad Institute of MIT and Harvard, Cambridge, MA, USA.
- Department of Biology, Chemistry and Pharmacy, Freie Universität, Berlin, Germany.
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