1
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Adampourezare M, Nikzad B, Amini M, Sheibani N. Fluorimetric detection of DNA methylation by cerium oxide nanoparticles for early cancer diagnosis. Heliyon 2024; 10:e28695. [PMID: 38586346 PMCID: PMC10998132 DOI: 10.1016/j.heliyon.2024.e28695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 03/21/2024] [Accepted: 03/22/2024] [Indexed: 04/09/2024] Open
Abstract
In this study, a very sensitive fluorescence nano-biosensor was developed using CeO2 nanoparticles for the rapid detection of DNA methylation. The characteristics of CeO2 nanoparticles were determined by transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) spectroscopy, UV-visible spectroscopy, and fluorescence spectroscopy. The CeO2 nanoparticles were reacted with a single-stranded DNA (ssDNA) probe, and then methylated and unmethylated target DNAs hybridized with an ssDNA probe, and the fluorescence emission was measured. Upon adding the target unmethylated and methylated ssDNA, the fluorescence intensity increased in the linear range of concentration from 2 × 10-13 - 10-18 M. The limit of detection (LOD) was 1.597 × 10-6 M for methylated DNA and 1.043 × 10-6 M for unmethylated DNA. The fluorescence emission intensity of methylated sequences was higher than of that unmethylated sequences. The fabricated DNA nanobiosensor showed a fluorescence emission at 420 nm with an excitation wavelength of 280 nm. The impact of CeO2 binding on methylated and unmethylated DNA was further demonstrated by agarose gel electrophoresis. Finally, the actual sample analysis suggested that the nanobiosensor could have practical applications for detecting methylation in the human plasma samples.
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Affiliation(s)
- Mina Adampourezare
- Research Center of Bioscience and Biotechnology, University of Tabriz, Tabriz, Iran
| | - Behzad Nikzad
- Research Center of Bioscience and Biotechnology, University of Tabriz, Tabriz, Iran
| | - Mojtaba Amini
- Department of Inorganic Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, Iran
| | - Nader Sheibani
- Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison WI 53705, USA
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2
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Kriukienė E, Tomkuvienė M, Klimašauskas S. 5-Hydroxymethylcytosine: the many faces of the sixth base of mammalian DNA. Chem Soc Rev 2024; 53:2264-2283. [PMID: 38205583 DOI: 10.1039/d3cs00858d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2024]
Abstract
Epigenetic phenomena play a central role in cell regulatory processes and are important factors for understanding complex human disease. One of the best understood epigenetic mechanisms is DNA methylation. In the mammalian genome, cytosines (C) in CpG dinucleotides were long known to undergo methylation at the 5-position of the pyrimidine ring (mC). Later it was found that mC can be oxidized to 5-hydroxymethylcytosine (hmC) or even further to 5-formylcytosine (fC) and to 5-carboxylcytosine (caC) by the action of 2-oxoglutarate-dependent dioxygenases of the TET family. These findings unveiled a long elusive mechanism of active DNA demethylation and bolstered a wave of studies in the area of epigenetic regulation in mammals. This review is dedicated to critical assessment of recent data on biochemical and chemical aspects of the formation and conversion of hmC in DNA, analytical techniques used for detection and mapping of this nucleobase in mammalian genomes as well as epigenetic roles of hmC in DNA replication, transcription, cell differentiation and human disease.
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Affiliation(s)
- Edita Kriukienė
- Institute of Biotechnology, Life Sciences Center, Vilnius University, Saulėtekio al. 7, LT-10257 Vilnius, Lithuania.
| | - Miglė Tomkuvienė
- Institute of Biotechnology, Life Sciences Center, Vilnius University, Saulėtekio al. 7, LT-10257 Vilnius, Lithuania.
| | - Saulius Klimašauskas
- Institute of Biotechnology, Life Sciences Center, Vilnius University, Saulėtekio al. 7, LT-10257 Vilnius, Lithuania.
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3
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Lee SM. Detecting DNA hydroxymethylation: exploring its role in genome regulation. BMB Rep 2024; 57:135-142. [PMID: 38449301 PMCID: PMC10979348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 01/15/2024] [Accepted: 02/01/2024] [Indexed: 03/08/2024] Open
Abstract
DNA methylation is one of the most extensively studied epigenetic regulatory mechanisms, known to play crucial roles in various organisms. It has been implicated in the regulation of gene expression and chromatin changes, ranging from global alterations during cell state transitions to locus-specific modifications. 5-hydroxymethylcytosine (5hmC) is produced by a major oxidation, from 5-methylcytosine (5mC), catalyzed by the ten-eleven translocation (TET) enzymes, and is gradually being recognized for its significant role in genome regulation. With the development of state-of-the-art experimental techniques, it has become possible to detect and distinguish 5mC and 5hmC at base resolution. Various techniques have evolved, encompassing chemical and enzymatic approaches, as well as thirdgeneration sequencing techniques. These advancements have paved the way for a thorough exploration of the role of 5hmC across a diverse array of cell types, from embryonic stem cells (ESCs) to various differentiated cells. This review aims to comprehensively report on recent techniques and discuss the emerging roles of 5hmC. [BMB Reports 2024; 57(3): 135-142].
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Affiliation(s)
- Sun-Min Lee
- Department of Physics, Konkuk Univeristy, Seoul 05029, Korea
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4
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Ghadirian N, Morgan RD, Horton NC. DNA Sequence Control of Enzyme Filamentation and Activation of the SgrAI Endonuclease. Biochemistry 2024; 63:326-338. [PMID: 38207281 DOI: 10.1021/acs.biochem.3c00313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2024]
Abstract
Enzyme polymerization (also known as filamentation) has emerged as a new layer of enzyme regulation. SgrAI is a sequence-dependent DNA endonuclease that forms polymeric filaments with enhanced DNA cleavage activity as well as altered DNA sequence specificity. To better understand this unusual regulatory mechanism, full global kinetic modeling of the reaction pathway, including the enzyme filamentation steps, has been undertaken. Prior work with the primary DNA recognition sequence cleaved by SgrAI has shown how the kinetic rate constants of each reaction step are tuned to maximize activation and DNA cleavage while minimizing the extent of DNA cleavage to the host genome. In the current work, we expand on our prior study by now including DNA cleavage of a secondary recognition sequence, to understand how the sequence of the bound DNA modulates filamentation and activation of SgrAI. The work shows that an allosteric equilibrium between low and high activity states is modulated by the sequence of bound DNA, with primary sequences more prone to activation and filament formation, while SgrAI bound to secondary recognition sequences favor the low (and nonfilamenting) state by up to 40-fold. In addition, the degree of methylation of secondary sequences in the host organism, Streptomyces griseus, is now reported for the first time and shows that as predicted, these sequences are left unprotected from the SgrAI endonuclease making sequence specificity critical in this unusual filament-forming enzyme.
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Affiliation(s)
- Niloofar Ghadirian
- Department of Chemistry & Biochemistry, University of Arizona, Tucson, Arizona 85721, United States
| | - Richard D Morgan
- New England Biolabs, Inc., Ipswich, Massachusetts 01938, United States
| | - Nancy C Horton
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, Arizona 85721, United States
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5
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N M, Kumar PS, Manna D. Chemical Methods to Identify Epigenetic Modifications in Cytosine Bases. Chem Asian J 2024; 19:e202301005. [PMID: 38206202 DOI: 10.1002/asia.202301005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 01/01/2024] [Accepted: 01/04/2024] [Indexed: 01/12/2024]
Abstract
Chemical modifications to Cytosine bases are among the most studied epigenetic markers and their detection in the human genome plays a crucial role in gaining more insights about gene regulation, prognosis of genetic disorders and unraveling genetic inheritance patterns. The Cytosine methylated at the 5th position and oxidized derivatives thereof generated in the demethylation pathways, perform separate and unique epigenetic functions in an organism. As the presence of various Cytosine modifications is associated with diverse diseases, including cancer, there has been a strong focus on developing methods, both chemical and alternative approaches, capable of detecting these modifications at a single-base resolution across the entire genome. In this comprehensive review, we aim to consolidate the various chemical methods and understanding their chemistry that have been established to date for the detection of various Cytosine modifications.
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Affiliation(s)
- Madhumitha N
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal, Madhya Pradesh, India
| | - Parvathy S Kumar
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal, Madhya Pradesh, India
| | - Debasish Manna
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal, Madhya Pradesh, India
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6
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Zimmerman EH, Ramsey EL, Hunter KE, Villadelgado SM, Phillips CM, Shipman RT, Forsyth MH. The Helicobacter pylori methylome is acid-responsive due to regulation by the two-component system ArsRS and the type I DNA methyltransferase HsdM1 (HP0463). J Bacteriol 2024; 206:e0030923. [PMID: 38179929 PMCID: PMC10810217 DOI: 10.1128/jb.00309-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2023] [Accepted: 12/14/2023] [Indexed: 01/06/2024] Open
Abstract
In addition to its role in genome protection, DNA methylation can regulate gene expression. In this study, we characterized the impact of acidity, phase variation, and the ArsRS TCS on the expression of the Type I m6A DNA methyltransferase HsdM1 (HP0463) of Helicobacter pylori 26695 and their subsequent effects on the methylome. Transcription of hsdM1 increases at least fourfold in the absence of the sensory histidine kinase ArsS, the major acid-sensing protein of H. pylori. hsdM1 exists in the phase-variable operon hsdR1-hsdM1. Phase-locking hsdR1 (HP0464), the restriction endonuclease gene, has significant impacts on the transcription of hsdM1. To determine the impacts of methyltransferase transcription patterns on the methylome, we conducted methylome sequencing on samples cultured at pH 7 or pH 5. We found differentially methylated motifs between these growth conditions and that deletions of arsS and/or hsdM1 interfere with the epigenetic acid response. Deletion of arsS leads to altered activity of HsdM1 and multiple other methyltransferases under both pH conditions indicating that the ArsRS TCS, in addition to direct effects on regulon transcription during acid acclimation, may also indirectly impact gene expression via regulation of the methylome. We determined the target motif of HsdM1 (HP0463) to be the complementary bipartite sequence pair 5'-TCAm6AVN6TGY-3' and 3'-AGTN6GAm6ACA-5'. This complex regulation of DNA methyltransferases, and thus differential methylation patterns, may have implications for the decades-long persistent infection by H. pylori. IMPORTANCE This study expands the possibilities for complex, epigenomic regulation in Helicobacter pylori. We demonstrate that the H. pylori methylome is plastic and acid sensitive via the two-component system ArsRS and the DNA methyltransferase HsdM1. The control of a methyltransferase by ArsRS may allow for a layered response to changing acidity. Likely, an early response whereby ArsR~P affects regulon expression, including the methyltransferase hsdM1. Then, a somewhat later effect as the altered methylome, due to altered HsdM1 expression, subsequently alters the expression of other genes involved in acclimation. The intermediate methylation of certain motifs supports the hypothesis that methyltransferases play a regulatory role. Untangling this additional web of regulation could play a key role in understanding H. pylori colonization and persistence.
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Affiliation(s)
| | - Erin L. Ramsey
- Department of Biology, William & Mary, Williamsburg, Virginia, USA
| | | | | | | | - Ryan T. Shipman
- Department of Biology, William & Mary, Williamsburg, Virginia, USA
| | - Mark H. Forsyth
- Department of Biology, William & Mary, Williamsburg, Virginia, USA
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7
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van Dijk EL, Naquin D, Gorrichon K, Jaszczyszyn Y, Ouazahrou R, Thermes C, Hernandez C. Genomics in the long-read sequencing era. Trends Genet 2023; 39:649-671. [PMID: 37230864 DOI: 10.1016/j.tig.2023.04.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 04/21/2023] [Accepted: 04/25/2023] [Indexed: 05/27/2023]
Abstract
Long-read sequencing (LRS) technologies have provided extremely powerful tools to explore genomes. While in the early years these methods suffered technical limitations, they have recently made significant progress in terms of read length, throughput, and accuracy and bioinformatics tools have strongly improved. Here, we aim to review the current status of LRS technologies, the development of novel methods, and the impact on genomics research. We will explore the most impactful recent findings made possible by these technologies focusing on high-resolution sequencing of genomes and transcriptomes and the direct detection of DNA and RNA modifications. We will also discuss how LRS methods promise a more comprehensive understanding of human genetic variation, transcriptomics, and epigenetics for the coming years.
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Affiliation(s)
- Erwin L van Dijk
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France.
| | - Delphine Naquin
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
| | - Kévin Gorrichon
- National Center of Human Genomics Research (CNRGH), 91000 Évry-Courcouronnes, France
| | - Yan Jaszczyszyn
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
| | - Rania Ouazahrou
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
| | - Claude Thermes
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
| | - Céline Hernandez
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
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8
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Kong Y, Mead EA, Fang G. Navigating the pitfalls of mapping DNA and RNA modifications. Nat Rev Genet 2023; 24:363-381. [PMID: 36653550 PMCID: PMC10722219 DOI: 10.1038/s41576-022-00559-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/21/2022] [Indexed: 01/19/2023]
Abstract
Chemical modifications to nucleic acids occur across the kingdoms of life and carry important regulatory information. Reliable high-resolution mapping of these modifications is the foundation of functional and mechanistic studies, and recent methodological advances based on next-generation sequencing and long-read sequencing platforms are critical to achieving this aim. However, mapping technologies may have limitations that sometimes lead to inconsistent results. Some of these limitations are technical in nature and specific to certain types of technology. Here, however, we focus on common (yet not always widely recognized) pitfalls that are shared among frequently used mapping technologies and discuss strategies to help technology developers and users mitigate their effects. Although the emphasis is primarily on DNA modifications, RNA modifications are also discussed.
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Affiliation(s)
- Yimeng Kong
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Edward A Mead
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Gang Fang
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
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9
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Searle B, Müller M, Carell T, Kellett A. Third-Generation Sequencing of Epigenetic DNA. Angew Chem Int Ed Engl 2023; 62:e202215704. [PMID: 36524852 DOI: 10.1002/anie.202215704] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 12/14/2022] [Accepted: 12/15/2022] [Indexed: 12/23/2022]
Abstract
The discovery of epigenetic bases has revolutionised the understanding of disease and development. Among the most studied epigenetic marks are cytosines covalently modified at the 5 position. In order to gain insight into their biological significance, the ability to determine their spatiotemporal distribution within the genome is essential. Techniques for sequencing on "next-generation" platforms often involve harsh chemical treatments leading to sample degradation. Third-generation sequencing promises to further revolutionise the field by providing long reads, enabling coverage of highly repetitive regions of the genome or structural variants considered unmappable by next generation sequencing technology. While the ability of third-generation platforms to directly detect epigenetic modifications is continuously improving, at present chemical or enzymatic derivatisation presents the most convenient means of enhancing reliability. This Review presents techniques available for the detection of cytosine modifications on third-generation platforms.
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Affiliation(s)
- Bethany Searle
- SSPC, the SFI Research Centre for Pharmaceuticals, School of Chemical Sciences, Dublin City University, Glasnevin, Dublin 9, Dublin, Ireland
| | - Markus Müller
- Department of Chemistry, Ludwig-Maximilians Universität München, Butenandtstr. 5-13, 81377, Munich, Germany
| | - Thomas Carell
- Department of Chemistry, Ludwig-Maximilians Universität München, Butenandtstr. 5-13, 81377, Munich, Germany
| | - Andrew Kellett
- SSPC, the SFI Research Centre for Pharmaceuticals, School of Chemical Sciences, Dublin City University, Glasnevin, Dublin 9, Dublin, Ireland
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10
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Furuta Y, Miura F, Ichise T, Nakayama SMM, Ikenaka Y, Zorigt T, Tsujinouchi M, Ishizuka M, Ito T, Higashi H. A GCDGC-specific DNA (cytosine-5) methyltransferase that methylates the GCWGC sequence on both strands and the GCSGC sequence on one strand. PLoS One 2022; 17:e0265225. [PMID: 35312710 PMCID: PMC8936443 DOI: 10.1371/journal.pone.0265225] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Accepted: 02/24/2022] [Indexed: 11/18/2022] Open
Abstract
5-Methylcytosine is one of the major epigenetic marks of DNA in living organisms. Some bacterial species possess DNA methyltransferases that modify cytosines on both strands to produce fully-methylated sites or on either strand to produce hemi-methylated sites. In this study, we characterized a DNA methyltransferase that produces two sequences with different methylation patterns: one methylated on both strands and another on one strand. M.BatI is the orphan DNA methyltransferase of Bacillus anthracis coded in one of the prophages on the chromosome. Analysis of M.BatI modified DNA by bisulfite sequencing revealed that the enzyme methylates the first cytosine in sequences of 5ʹ-GCAGC-3ʹ, 5ʹ-GCTGC-3ʹ, and 5ʹ-GCGGC-3ʹ, but not of 5ʹ-GCCGC-3ʹ. This resulted in the production of fully-methylated 5ʹ-GCWGC-3ʹ and hemi-methylated 5ʹ-GCSGC-3ʹ. M.BatI also showed toxicity when expressed in E. coli, which was caused by a mechanism other than DNA modification activity. Homologs of M.BatI were found in other Bacillus species on different prophage like regions, suggesting the spread of the gene by several different phages. The discovery of the DNA methyltransferase with unique modification target specificity suggested unrevealed diversity of target sequences of bacterial cytosine DNA methyltransferase.
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Affiliation(s)
- Yoshikazu Furuta
- Division of Infection and Immunity, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Japan
- * E-mail:
| | - Fumihito Miura
- Department of Biochemistry, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan
| | - Takahiro Ichise
- Laboratory of Toxicology, Department of Environmental Veterinary Sciences, School of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | - Shouta M. M. Nakayama
- Laboratory of Toxicology, Department of Environmental Veterinary Sciences, School of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | - Yoshinori Ikenaka
- Laboratory of Toxicology, Department of Environmental Veterinary Sciences, School of Veterinary Medicine, Hokkaido University, Sapporo, Japan
- Water Research Group, Unit for Environmental Sciences and Management, North-West University, Potchefstroom, South Africa
| | - Tuvshinzaya Zorigt
- Division of Infection and Immunity, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Japan
| | - Mai Tsujinouchi
- Division of Infection and Immunity, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Japan
| | - Mayumi Ishizuka
- Laboratory of Toxicology, Department of Environmental Veterinary Sciences, School of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | - Takashi Ito
- Department of Biochemistry, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan
| | - Hideaki Higashi
- Division of Infection and Immunity, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Japan
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11
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Tost J. Current and Emerging Technologies for the Analysis of the Genome-Wide and Locus-Specific DNA Methylation Patterns. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1389:395-469. [DOI: 10.1007/978-3-031-11454-0_16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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12
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Yan B, Wang D, Vaisvila R, Sun Z, Ettwiller L. Methyl-SNP-seq reveals dual readouts of methylome and variome at molecule resolution while enabling target enrichment. Genome Res 2022; 32:2079-2091. [PMID: 36332968 PMCID: PMC9808626 DOI: 10.1101/gr.277080.122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 10/31/2022] [Indexed: 11/06/2022]
Abstract
Covalent modifications of genomic DNA are crucial for most organisms to survive. Amplicon-based high-throughput sequencing technologies erase all DNA modifications to retain only sequence information for the four canonical nucleobases, necessitating specialized technologies for ascertaining epigenetic information. To also capture base modification information, we developed Methyl-SNP-seq, a technology that takes advantage of the complementarity of the double helix to extract the methylation and original sequence information from a single DNA molecule. More specifically, Methyl-SNP-seq uses bisulfite conversion of one of the strands to identify cytosine methylation while retaining the original four-bases sequence information on the other strand. As both strands are locked together to link the dual readouts on a single paired-end read, Methyl-SNP-seq allows detecting the methylation status of any DNA even without a reference genome. Because one of the strands retains the original four nucleotide composition, Methyl-SNP-seq can also be used in conjunction with standard sequence-specific probes for targeted enrichment and amplification. We show the usefulness of this technology in a broad spectrum of applications ranging from allele-specific methylation analysis in humans to identification of methyltransferase specificity in complex bacterial communities.
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Affiliation(s)
- Bo Yan
- New England Biolabs, Incorporated, Ipswich, Massachusetts 01938, USA
| | - Duan Wang
- SLC Management, Wellesley Hills, Massachusetts 02481, USA
| | | | - Zhiyi Sun
- New England Biolabs, Incorporated, Ipswich, Massachusetts 01938, USA
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13
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Baum C, Lin YC, Fomenkov A, Anton BP, Chen L, Yan B, Evans TC, Roberts RJ, Tolonen AC, Ettwiller L. Rapid identification of methylase specificity (RIMS-seq) jointly identifies methylated motifs and generates shotgun sequencing of bacterial genomes. Nucleic Acids Res 2021; 49:e113. [PMID: 34417598 PMCID: PMC8565308 DOI: 10.1093/nar/gkab705] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 07/29/2021] [Accepted: 08/16/2021] [Indexed: 11/21/2022] Open
Abstract
DNA methylation is widespread amongst eukaryotes and prokaryotes to modulate gene expression and confer viral resistance. 5-Methylcytosine (m5C) methylation has been described in genomes of a large fraction of bacterial species as part of restriction-modification systems, each composed of a methyltransferase and cognate restriction enzyme. Methylases are site-specific and target sequences vary across organisms. High-throughput methods, such as bisulfite-sequencing can identify m5C at base resolution but require specialized library preparations and single molecule, real-time (SMRT) sequencing usually misses m5C. Here, we present a new method called RIMS-seq (rapid identification of methylase specificity) to simultaneously sequence bacterial genomes and determine m5C methylase specificities using a simple experimental protocol that closely resembles the DNA-seq protocol for Illumina. Importantly, the resulting sequencing quality is identical to DNA-seq, enabling RIMS-seq to substitute standard sequencing of bacterial genomes. Applied to bacteria and synthetic mixed communities, RIMS-seq reveals new methylase specificities, supporting routine study of m5C methylation while sequencing new genomes.
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Affiliation(s)
- Chloé Baum
- New England Biolabs, Inc. 240 County Road Ipswich, MA 01938, USA.,Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, 91000 Évry, France
| | - Yu-Cheng Lin
- New England Biolabs, Inc. 240 County Road Ipswich, MA 01938, USA
| | - Alexey Fomenkov
- New England Biolabs, Inc. 240 County Road Ipswich, MA 01938, USA
| | - Brian P Anton
- New England Biolabs, Inc. 240 County Road Ipswich, MA 01938, USA
| | - Lixin Chen
- New England Biolabs, Inc. 240 County Road Ipswich, MA 01938, USA
| | - Bo Yan
- New England Biolabs, Inc. 240 County Road Ipswich, MA 01938, USA
| | - Thomas C Evans
- New England Biolabs, Inc. 240 County Road Ipswich, MA 01938, USA
| | | | - Andrew C Tolonen
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, 91000 Évry, France
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14
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Dai Y, Yuan BF, Feng YQ. Quantification and mapping of DNA modifications. RSC Chem Biol 2021; 2:1096-1114. [PMID: 34458826 PMCID: PMC8341653 DOI: 10.1039/d1cb00022e] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 05/20/2021] [Indexed: 12/13/2022] Open
Abstract
Apart from the four canonical nucleobases, DNA molecules carry a number of natural modifications. Substantial evidence shows that DNA modifications can regulate diverse biological processes. Dynamic and reversible modifications of DNA are critical for cell differentiation and development. Dysregulation of DNA modifications is closely related to many human diseases. The research of DNA modifications is a rapidly expanding area and has been significantly stimulated by the innovations of analytical methods. With the recent advances in methods and techniques, a series of new DNA modifications have been discovered in the genomes of prokaryotes and eukaryotes. Deciphering the biological roles of DNA modifications depends on the sensitive detection, accurate quantification, and genome-wide mapping of modifications in genomic DNA. This review provides an overview of the recent advances in analytical methods and techniques for both the quantification and genome-wide mapping of natural DNA modifications. We discuss the principles, advantages, and limitations of these developed methods. It is anticipated that new methods and techniques will resolve the current challenges in this burgeoning research field and expedite the elucidation of the functions of DNA modifications.
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Affiliation(s)
- Yi Dai
- Sauvage Center for Molecular Sciences, Department of Chemistry, Wuhan University Wuhan 430072 P. R. China +86-27-68755595 +86-27-68755595
| | - Bi-Feng Yuan
- Sauvage Center for Molecular Sciences, Department of Chemistry, Wuhan University Wuhan 430072 P. R. China +86-27-68755595 +86-27-68755595
- School of Health Sciences, Wuhan University Wuhan 430071 China
| | - Yu-Qi Feng
- Sauvage Center for Molecular Sciences, Department of Chemistry, Wuhan University Wuhan 430072 P. R. China +86-27-68755595 +86-27-68755595
- School of Health Sciences, Wuhan University Wuhan 430071 China
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15
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Tvedte ES, Gasser M, Sparklin BC, Michalski J, Hjelmen CE, Johnston JS, Zhao X, Bromley R, Tallon LJ, Sadzewicz L, Rasko DA, Dunning Hotopp JC. Comparison of long-read sequencing technologies in interrogating bacteria and fly genomes. G3 (BETHESDA, MD.) 2021; 11:jkab083. [PMID: 33768248 PMCID: PMC8495745 DOI: 10.1093/g3journal/jkab083] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 03/07/2021] [Indexed: 12/14/2022]
Abstract
The newest generation of DNA sequencing technology is highlighted by the ability to generate sequence reads hundreds of kilobases in length. Pacific Biosciences (PacBio) and Oxford Nanopore Technologies (ONT) have pioneered competitive long read platforms, with more recent work focused on improving sequencing throughput and per-base accuracy. We used whole-genome sequencing data produced by three PacBio protocols (Sequel II CLR, Sequel II HiFi, RS II) and two ONT protocols (Rapid Sequencing and Ligation Sequencing) to compare assemblies of the bacteria Escherichia coli and the fruit fly Drosophila ananassae. In both organisms tested, Sequel II assemblies had the highest consensus accuracy, even after accounting for differences in sequencing throughput. ONT and PacBio CLR had the longest reads sequenced compared to PacBio RS II and HiFi, and genome contiguity was highest when assembling these datasets. ONT Rapid Sequencing libraries had the fewest chimeric reads in addition to superior quantification of E. coli plasmids versus ligation-based libraries. The quality of assemblies can be enhanced by adopting hybrid approaches using Illumina libraries for bacterial genome assembly or polishing eukaryotic genome assemblies, and an ONT-Illumina hybrid approach would be more cost-effective for many users. Genome-wide DNA methylation could be detected using both technologies, however ONT libraries enabled the identification of a broader range of known E. coli methyltransferase recognition motifs in addition to undocumented D. ananassae motifs. The ideal choice of long read technology may depend on several factors including the question or hypothesis under examination. No single technology outperformed others in all metrics examined.
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Affiliation(s)
- Eric S Tvedte
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Mark Gasser
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Benjamin C Sparklin
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Jane Michalski
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Carl E Hjelmen
- Department of Biology, Texas A&M University, College Station, TX 77843, USA
| | - J Spencer Johnston
- Department of Entomology, Texas A&M University, College Station, TX 77843, USA
| | - Xuechu Zhao
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Robin Bromley
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Luke J Tallon
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Lisa Sadzewicz
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - David A Rasko
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Julie C Dunning Hotopp
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Greenebaum Cancer Center, University of Maryland School of Medicine, Baltimore, MD 21201, USA
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16
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Genome-wide detection of cytosine methylation by single molecule real-time sequencing. Proc Natl Acad Sci U S A 2021; 118:2019768118. [PMID: 33495335 PMCID: PMC7865158 DOI: 10.1073/pnas.2019768118] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Single molecule real-time (SMRT) sequencing theoretically offers the opportunity to directly assess certain base modifications of native DNA molecules without any prior chemical/enzymatic conversions and PCR amplification, using kinetic signals of a DNA polymerase. However, the kinetic signal changes caused by 5mC modification are extremely subtle. Hence, the robust genome-wide measurement of 5mC modification has not been achieved. We enhanced 5mC detection using SMRT sequencing by holistically analyzing kinetic signals of a DNA polymerase and sequence context for every base within a measurement window. We employed a convolutional neural network to train a methylation classification model, leading to genome-wide 5mC detection. The sensitivity and specificity reached 90% and 94%, with a 99% correlation of overall methylation level with bisulfite sequencing. 5-Methylcytosine (5mC) is an important type of epigenetic modification. Bisulfite sequencing (BS-seq) has limitations, such as severe DNA degradation. Using single molecule real-time sequencing, we developed a methodology to directly examine 5mC. This approach holistically examined kinetic signals of a DNA polymerase (including interpulse duration and pulse width) and sequence context for every nucleotide within a measurement window, termed the holistic kinetic (HK) model. The measurement window of each analyzed double-stranded DNA molecule comprised 21 nucleotides with a cytosine in a CpG site in the center. We used amplified DNA (unmethylated) and M.SssI-treated DNA (methylated) (M.SssI being a CpG methyltransferase) to train a convolutional neural network. The area under the curve for differentiating methylation states using such samples was up to 0.97. The sensitivity and specificity for genome-wide 5mC detection at single-base resolution reached 90% and 94%, respectively. The HK model was then tested on human–mouse hybrid fragments in which each member of the hybrid had a different methylation status. The model was also tested on human genomic DNA molecules extracted from various biological samples, such as buffy coat, placental, and tumoral tissues. The overall methylation levels deduced by the HK model were well correlated with those by BS-seq (r = 0.99; P < 0.0001) and allowed the measurement of allele-specific methylation patterns in imprinted genes. Taken together, this methodology has provided a system for simultaneous genome-wide genetic and epigenetic analyses.
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17
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Anton BP, Fomenkov A, Wu V, Roberts RJ. Genome-wide identification of 5-methylcytosine sites in bacterial genomes by high-throughput sequencing of MspJI restriction fragments. PLoS One 2021; 16:e0247541. [PMID: 33974631 PMCID: PMC8112702 DOI: 10.1371/journal.pone.0247541] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 04/26/2021] [Indexed: 11/19/2022] Open
Abstract
Single-molecule Real-Time (SMRT) sequencing can easily identify sites of N6-methyladenine and N4-methylcytosine within DNA sequences, but similar identification of 5-methylcytosine sites is not as straightforward. In prokaryotic DNA, methylation typically occurs within specific sequence contexts, or motifs, that are a property of the methyltransferases that "write" these epigenetic marks. We present here a straightforward, cost-effective alternative to both SMRT and bisulfite sequencing for the determination of prokaryotic 5-methylcytosine methylation motifs. The method, called MFRE-Seq, relies on excision and isolation of fully methylated fragments of predictable size using MspJI-Family Restriction Enzymes (MFREs), which depend on the presence of 5-methylcytosine for cleavage. We demonstrate that MFRE-Seq is compatible with both Illumina and Ion Torrent sequencing platforms and requires only a digestion step and simple column purification of size-selected digest fragments prior to standard library preparation procedures. We applied MFRE-Seq to numerous bacterial and archaeal genomic DNA preparations and successfully confirmed known motifs and identified novel ones. This method should be a useful complement to existing methodologies for studying prokaryotic methylomes and characterizing the contributing methyltransferases.
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Affiliation(s)
- Brian P. Anton
- Research Department, New England Biolabs, Ipswich, Massachusetts, United States of America
- * E-mail:
| | - Alexey Fomenkov
- Research Department, New England Biolabs, Ipswich, Massachusetts, United States of America
| | - Victoria Wu
- Research Department, New England Biolabs, Ipswich, Massachusetts, United States of America
- Wellesley College, Wellesley, Massachusetts, United States of America
| | - Richard J. Roberts
- Research Department, New England Biolabs, Ipswich, Massachusetts, United States of America
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18
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Spadar A, Perdigão J, Phelan J, Charleston J, Modesto A, Elias R, de Sessions PF, Hibberd ML, Campino S, Duarte A, Clark TG. Methylation analysis of Klebsiella pneumoniae from Portuguese hospitals. Sci Rep 2021; 11:6491. [PMID: 33753763 PMCID: PMC7985491 DOI: 10.1038/s41598-021-85724-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 02/11/2021] [Indexed: 12/13/2022] Open
Abstract
Klebsiella pneumoniae is an important nosocomial infectious agent with a high antimicrobial resistance (AMR) burden. The application of long read sequencing technologies is providing insights into bacterial chromosomal and putative extra-chromosomal genetic elements (PEGEs) associated with AMR, but also epigenetic DNA methylation, which is thought to play a role in cleavage of foreign DNA and expression regulation. Here, we apply the PacBio sequencing platform to eight Portuguese hospital isolates, including one carbapenemase producing isolate, to identify methylation motifs. The resulting assembled chromosomes were between 5.2 and 5.5Mbp in length, and twenty-six PEGEs were found. Four of our eight samples carry blaCTX-M-15, a dominant Extended Spectrum Beta Lactamase in Europe. We identified methylation motifs that control Restriction-Modification systems, including GATC of the DNA adenine methylase (Dam), which methylates N6-methyladenine (m6A) across all our K. pneumoniae assemblies. There was a consistent lack of methylation by Dam of the GATC motif downstream of two genes: fosA, a locus associated with low level fosfomycin resistance, and tnpB transposase on IncFIB(K) plasmids. Overall, we have constructed eight high quality reference genomes of K. pneumoniae, with insights into horizontal gene transfer and methylation m6A motifs.
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Affiliation(s)
- Anton Spadar
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - João Perdigão
- Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Lisboa, Portugal
| | - Jody Phelan
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - James Charleston
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Ana Modesto
- Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Lisboa, Portugal
| | - Rita Elias
- Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Lisboa, Portugal
| | | | - Martin L Hibberd
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Susana Campino
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Aida Duarte
- Faculdade de Farmácia, Universidade de Lisboa, Lisboa, Portugal
- Centro de Investigação Interdisciplinar Egas Moniz, Instituto Universitário Egas Moniz, Almada, Portugal
| | - Taane G Clark
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK.
- Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK.
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK.
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19
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Vandenbussche I, Sass A, Van Nieuwerburgh F, Pinto-Carbó M, Mannweiler O, Eberl L, Coenye T. Detection of cytosine methylation in Burkholderia cenocepacia by single-molecule real-time sequencing and whole-genome bisulfite sequencing. MICROBIOLOGY-SGM 2021; 167. [PMID: 33565960 DOI: 10.1099/mic.0.001027] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Research on prokaryotic epigenetics, the study of heritable changes in gene expression independent of sequence changes, led to the identification of DNA methylation as a versatile regulator of diverse cellular processes. Methylation of adenine bases is often linked to regulation of gene expression in bacteria, but cytosine methylation is also frequently observed. In this study, we present a complete overview of the cytosine methylome in Burkholderia cenocepacia, an opportunistic respiratory pathogen in cystic fibrosis patients. Single-molecule real-time (SMRT) sequencing was used to map all 4mC-modified cytosines, as analysis of the predicted MTases in the B. cenocepacia genome revealed the presence of a 4mC-specific phage MTase, M.BceJII, targeting GGCC sequences. Methylation motif GCGGCCGC was identified, and out of 6850 motifs detected across the genome, 2051 (29.9 %) were methylated at the fifth position. Whole-genome bisulfite sequencing (WGBS) was performed to map 5mC methylation and 1635 5mC-modified cytosines were identified in CpG motifs. A comparison of the genomic positions of the modified bases called by each method revealed no overlap, which confirmed the authenticity of the detected 4mC and 5mC methylation by SMRT sequencing and WGBS, respectively. Large inter-strain variation of the 4mC-methylated cytosines was observed when B. cenocepacia strains J2315 and K56-2 were compared, which suggests that GGCC methylation patterns in B. cenocepacia are strain-specific. It seems likely that 4mC methylation of GGCC is not involved in regulation of gene expression but rather is a remnant of bacteriophage invasion, in which methylation of the phage genome was crucial for protection against restriction-modification systems of B. cenocepacia.
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Affiliation(s)
- Ian Vandenbussche
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium
| | - Andrea Sass
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium
| | | | - Marta Pinto-Carbó
- Department of Plant and Microbial Microbiology, University of Zurich, Zurich, Switzerland
| | - Olga Mannweiler
- Department of Plant and Microbial Microbiology, University of Zurich, Zurich, Switzerland
| | - Leo Eberl
- Department of Plant and Microbial Microbiology, University of Zurich, Zurich, Switzerland
| | - Tom Coenye
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium
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20
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Nye TM, Fernandez NL, Simmons LA. A positive perspective on DNA methylation: regulatory functions of DNA methylation outside of host defense in Gram-positive bacteria. Crit Rev Biochem Mol Biol 2020; 55:576-591. [PMID: 33059472 DOI: 10.1080/10409238.2020.1828257] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The presence of post-replicative DNA methylation is pervasive among both prokaryotic and eukaryotic organisms. In bacteria, the study of DNA methylation has largely been in the context of restriction-modification systems, where DNA methylation serves to safeguard the chromosome against restriction endonuclease cleavage intended for invading DNA. There has been a growing recognition that the methyltransferase component of restriction-modification systems can also regulate gene expression, with important contributions to virulence factor gene expression in bacterial pathogens. Outside of restriction-modification systems, DNA methylation from orphan methyltransferases, which lack cognate restriction endonucleases, has been shown to regulate important processes, including DNA replication, DNA mismatch repair, and the regulation of gene expression. The majority of research and review articles have been focused on DNA methylation in the context of Gram-negative bacteria, with emphasis toward Escherichia coli, Caulobacter crescentus, and related Proteobacteria. Here we summarize the epigenetic functions of DNA methylation outside of host defense in Gram-positive bacteria, with a focus on the regulatory effects of both phase variable methyltransferases and DNA methyltransferases from traditional restriction-modification systems.
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Affiliation(s)
- Taylor M Nye
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Nicolas L Fernandez
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Lyle A Simmons
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
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21
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Abstract
Cellular DNA is constantly chemically altered by exogenous and endogenous agents. As all processes of life depend on the transmission of the genetic information, multiple biological processes exist to ensure genome integrity. Chemically damaged DNA has been linked to cancer and aging, therefore it is of great interest to map DNA damage formation and repair to elucidate the distribution of damage on a genome-wide scale. While the low abundance and inability to enzymatically amplify DNA damage are obstacles to genome-wide sequencing, new developments in the last few years have enabled high-resolution mapping of damaged bases. Recently, a number of DNA damage sequencing library construction strategies coupled to new data analysis pipelines allowed the mapping of specific DNA damage formation and repair at high and single nucleotide resolution. Strikingly, these advancements revealed that the distribution of DNA damage is heavily influenced by chromatin states and the binding of transcription factors. In the last seven years, these novel approaches have revealed new genomic maps of DNA damage distribution in a variety of organisms as generated by diverse chemical and physical DNA insults; oxidative stress, chemotherapeutic drugs, environmental pollutants, and sun exposure. Preferred sequences for damage formation and repair have been elucidated, thus making it possible to identify persistent weak spots in the genome as locations predicted to be vulnerable for mutation. As such, sequencing DNA damage will have an immense impact on our ability to elucidate mechanisms of disease initiation, and to evaluate and predict the efficacy of chemotherapeutic drugs.
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Affiliation(s)
- Cécile Mingard
- Department of Health Sciences and Technology, ETH Zürich, Schmelzbergstrasse 9, 8092 Zürich, Switzerland.
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22
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In Vivo Genome and Methylome Adaptation of cag-Negative Helicobacter pylori during Experimental Human Infection. mBio 2020; 11:mBio.01803-20. [PMID: 32843556 PMCID: PMC7448279 DOI: 10.1128/mbio.01803-20] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Exceptional genetic diversity and variability are hallmarks of Helicobacter pylori, but the biological role of this plasticity remains incompletely understood. Here, we had the rare opportunity to investigate the molecular evolution during the first weeks of H. pylori infection by comparing the genomes and epigenomes of H. pylori strain BCS 100 used to challenge human volunteers in a vaccine trial with those of bacteria reisolated from the volunteers 10 weeks after the challenge. The data provide molecular insights into the process of establishment of this highly versatile pathogen in 10 different human individual hosts, showing, for example, selection for changes in host-interaction molecules as well as changes in epigenetic methylation patterns. The data provide important clues to the early adaptation of H. pylori to new host niches after transmission, which we believe is vital to understand its success as a chronic pathogen and develop more efficient treatments and vaccines. Multiple studies have demonstrated rapid bacterial genome evolution during chronic infection with Helicobacter pylori. In contrast, little was known about genetic changes during the first stages of infection, when selective pressure is likely to be highest. Using single-molecule, real-time (SMRT) and Illumina sequencing technologies, we analyzed genome and methylome evolution during the first 10 weeks of infection by comparing the cag pathogenicity island (cagPAI)-negative H. pylori challenge strain BCS 100 with pairs of H. pylori reisolates from gastric antrum and corpus biopsy specimens of 10 human volunteers who had been infected with this strain as part of a vaccine trial. Most genetic changes detected in the reisolates affected genes with a surface-related role or a predicted function in peptide uptake. Apart from phenotypic changes of the bacterial envelope, a duplication of the catalase gene was observed in one reisolate, which resulted in higher catalase activity and improved survival under oxidative stress conditions. The methylomes also varied in some of the reisolates, mostly by activity switching of phase-variable methyltransferase (MTase) genes. The observed in vivo mutation spectrum was remarkable for a very high proportion of nonsynonymous mutations. Although the data showed substantial within-strain genome diversity in the challenge strain, most antrum and corpus reisolates from the same volunteers were highly similar to each other, indicating that the challenge infection represents a major selective bottleneck shaping the transmitted population. Our findings suggest rapid in vivo selection of H. pylori during early-phase infection providing adaptation to different individuals by common mechanisms of genetic and epigenetic alterations.
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23
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Coy SR, Gann ER, Papoulis SE, Holder ME, Ajami NJ, Petrosino JF, Zinser ER, Van Etten JL, Wilhelm SW. SMRT Sequencing of Paramecium Bursaria Chlorella Virus-1 Reveals Diverse Methylation Stability in Adenines Targeted by Restriction Modification Systems. Front Microbiol 2020; 11:887. [PMID: 32508769 PMCID: PMC7248222 DOI: 10.3389/fmicb.2020.00887] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 04/16/2020] [Indexed: 12/31/2022] Open
Abstract
Chloroviruses (family Phycodnaviridae) infect eukaryotic, freshwater, unicellular green algae. A unique feature of these viruses is an abundance of DNA methyltransferases, with isolates dedicating up to 4.5% of their protein coding potential to these genes. This diversity highlights just one of the long-standing values of the chlorovirus model system; where group-wide epigenomic characterization might begin to elucidate the function(s) of DNA methylation in large dsDNA viruses. We characterized DNA modifications in the prototype chlorovirus, PBCV-1, using single-molecule real time (SMRT) sequencing (aka PacBio). Results were compared to total available sites predicted in silico based on DNA sequence alone. SMRT-software detected N6-methyl-adenine (m6A) at GATC and CATG recognition sites, motifs previously shown to be targeted by PBCV-1 DNA methyltransferases M.CviAI and M. CviAII, respectively. At the same time, PacBio analyses indicated that 10.9% of the PBCV-1 genome had large interpulse duration ratio (ipdRatio) values, the primary metric for DNA modification identification. These events represent 20.6x more sites than can be accounted for by all available adenines in GATC and CATG motifs, suggesting base or backbone modifications other than methylation might be present. To define methylation stability, we cross-compared methylation status of each GATC and CATG sequence in three biological replicates and found ∼81% of sites were stably methylated, while ∼2% consistently lack methylation. The remaining 17% of sites were stochastically methylated. When methylation status was analyzed for both strands of each target, we show that palindromes existed in completely non-methylated states, fully-methylated states, or hemi-methylated states, though GATC sites more often lack methylation than CATG sequences. Given that both sequences are targeted by not just methyltransferases, but by restriction endonucleases that are together encoded by PBCV-1 as virus-originating restriction modification (RM) systems, there is strong selective pressure to modify all target sites. The finding that most instances of non-methylation are associated with hemi-methylation is congruent with observations that hemi-methylated palindromes are resistant to cleavage by restriction endonucleases. However, sites where hemi-methylation is conserved might represent a unique regulatory function for PBCV-1. This study serves as a baseline for future investigation into the epigenomics of chloroviruses and their giant virus relatives.
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Affiliation(s)
- Samantha R. Coy
- Department of Microbiology, The University of Tennessee, Knoxville, Knoxville, TN, United States
- BioSciences at Rice, Rice University, Houston, TX, United States
| | - Eric R. Gann
- Department of Microbiology, The University of Tennessee, Knoxville, Knoxville, TN, United States
| | - Spiridon E. Papoulis
- Department of Microbiology, The University of Tennessee, Knoxville, Knoxville, TN, United States
| | - Michael E. Holder
- Alkek Center for Metagenomics and Microbiome Research, Baylor College of Medicine, Houston, TX, United States
| | - Nadim J. Ajami
- Alkek Center for Metagenomics and Microbiome Research, Baylor College of Medicine, Houston, TX, United States
| | - Joseph F. Petrosino
- Alkek Center for Metagenomics and Microbiome Research, Baylor College of Medicine, Houston, TX, United States
| | - Erik R. Zinser
- Department of Microbiology, The University of Tennessee, Knoxville, Knoxville, TN, United States
| | - James L. Van Etten
- Department of Plant Pathology and the Nebraska Center for Virology, University of Nebraska, Lincoln, NE, United States
| | - Steven W. Wilhelm
- Department of Microbiology, The University of Tennessee, Knoxville, Knoxville, TN, United States
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24
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Zeng F, Fang G, Yao L. A Deep Neural Network for Identifying DNA N4-Methylcytosine Sites. Front Genet 2020; 11:209. [PMID: 32211035 PMCID: PMC7067889 DOI: 10.3389/fgene.2020.00209] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 02/21/2020] [Indexed: 11/25/2022] Open
Abstract
Motivation: N4-methylcytosine (4mC) plays an important role in host defense and transcriptional regulation. Accurate identification of 4mc sites provides a more comprehensive understanding of its biological effects. At present, the traditional machine learning algorithms are used in the research on 4mC sites prediction, but the complexity of the algorithms is relatively high, which is not suitable for the processing of large data sets, and the accuracy of prediction needs to be improved. Therefore, it is necessary to develop a new and effective method to accurately identify 4mC sites. Results: In this work, we found a large number of 4mC sites and non 4mC sites of Caenorhabditis elegans (C. elegans) from the latest MethSMRT website, which greatly expanded the dataset of C. elegans, and developed a hybrid deep neural network framework named 4mcDeep-CBI, aiming to identify 4mC sites. In order to obtain the high latitude information of the feature, we input the preliminary extracted features into the Convolutional Neural Network (CNN) and Bidirectional Long Short Term Memory network (BLSTM) to generate advanced features. Taking the advanced features as algorithm input, we have proposed an integrated algorithm to improve feature representation. Experimental results on large new dataset show that the proposed predictor is able to achieve generally better performance in identifying 4mC sites as compared to the state-of-art predictor. Notably, this is the first study of identifying 4mC sites using deep neural network. Moreover, our model runs much faster than the state-of-art predictor.
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Affiliation(s)
- Feng Zeng
- School of Computer Science and Engineering, Central South University, Changsha, China
| | - Guanyun Fang
- School of Computer Science and Engineering, Central South University, Changsha, China
| | - Lan Yao
- College of Mathematics and Econometrics, Hunan University, Changsha, China
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25
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Xu L, Seki M. Recent advances in the detection of base modifications using the Nanopore sequencer. J Hum Genet 2020; 65:25-33. [PMID: 31602005 PMCID: PMC7087776 DOI: 10.1038/s10038-019-0679-0] [Citation(s) in RCA: 78] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 09/22/2019] [Accepted: 09/26/2019] [Indexed: 12/29/2022]
Abstract
DNA and RNA modifications have important functions, including the regulation of gene expression. Existing methods based on short-read sequencing for the detection of modifications show difficulty in determining the modification patterns of single chromosomes or an entire transcript sequence. Furthermore, the kinds of modifications for which detection methods are available are very limited. The Nanopore sequencer is a single-molecule, long-read sequencer that can directly sequence RNA as well as DNA. Moreover, the Nanopore sequencer detects modifications on long DNA and RNA molecules. In this review, we mainly focus on base modification detection in the DNA and RNA of mammals using the Nanopore sequencer. We summarize current studies of modifications using the Nanopore sequencer, detection tools using statistical tests or machine learning, and applications of this technology, such as analyses of open chromatin, DNA replication, and RNA metabolism.
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Affiliation(s)
- Liu Xu
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba, Japan
| | - Masahide Seki
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba, Japan.
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26
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Gouil Q, Keniry A. Latest techniques to study DNA methylation. Essays Biochem 2019; 63:639-648. [PMID: 31755932 PMCID: PMC6923321 DOI: 10.1042/ebc20190027] [Citation(s) in RCA: 79] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 10/23/2019] [Accepted: 10/23/2019] [Indexed: 12/15/2022]
Abstract
Bisulfite sequencing is a powerful technique to detect 5-methylcytosine in DNA that has immensely contributed to our understanding of epigenetic regulation in plants and animals. Meanwhile, research on other base modifications, including 6-methyladenine and 4-methylcytosine that are frequent in prokaryotes, has been impeded by the lack of a comparable technique. Bisulfite sequencing also suffers from a number of drawbacks that are difficult to surmount, among which DNA degradation, lack of specificity, or short reads with low sequence diversity. In this review, we explore the recent refinements to bisulfite sequencing protocols that enable targeting genomic regions of interest, detecting derivatives of 5-methylcytosine, and mapping single-cell methylomes. We then present the unique advantage of long-read sequencing in detecting base modifications in native DNA and highlight the respective strengths and weaknesses of PacBio and Nanopore sequencing for this application. Although analysing epigenetic data from long-read platforms remains challenging, the ability to detect various modified bases from a universal sample preparation, in addition to the mapping and phasing advantages of the longer read lengths, provide long-read sequencing with a decisive edge over short-read bisulfite sequencing for an expanding number of applications across kingdoms.
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Affiliation(s)
- Quentin Gouil
- Epigenetics and Development Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Australia
| | - Andrew Keniry
- Epigenetics and Development Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Australia
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Sánchez-Busó L, Golparian D, Parkhill J, Unemo M, Harris SR. Genetic variation regulates the activation and specificity of Restriction-Modification systems in Neisseria gonorrhoeae. Sci Rep 2019; 9:14685. [PMID: 31605008 PMCID: PMC6789123 DOI: 10.1038/s41598-019-51102-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2019] [Accepted: 09/25/2019] [Indexed: 01/14/2023] Open
Abstract
Restriction-Modification systems (RMS) are one of the main mechanisms of defence against foreign DNA invasion and can have an important role in the regulation of gene expression. The obligate human pathogen Neisseria gonorrhoeae carries one of the highest loads of RMS in its genome; between 13 to 15 of the three main types. Previous work has described their organization in the reference genome FA1090 and has inferred the associated methylated motifs. Here, we studied the structure of RMS and target methylated motifs in 25 gonococcal strains sequenced with Single Molecule Real-Time (SMRT) technology, which provides data on DNA modification. The results showed a variable picture of active RMS in different strains, with phase variation switching the activity of Type III RMS, and both the activity and specificity of a Type I RMS. Interestingly, the Dam methylase was found in place of the NgoAXI endonuclease in two of the strains, despite being previously thought to be absent in the gonococcus. We also identified the real methylation target of NgoAXII as 5′-GCAGA-3′, different from that previously described. Results from this work give further insights into the diversity and dynamics of RMS and methylation patterns in N. gonorrhoeae.
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Affiliation(s)
- Leonor Sánchez-Busó
- Centre for Genomic Pathogen Surveillance, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK. .,Big Data Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
| | - Daniel Golparian
- WHO Collaborating Centre for Gonorrhoea and other Sexually Transmitted Infections, National Reference Laboratory for Sexually Transmitted Infections, Department of Laboratory Medicine, Clinical Microbiology, Faculty of Medicine and Health, Örebro University, Örebro, Sweden
| | - Julian Parkhill
- Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
| | - Magnus Unemo
- WHO Collaborating Centre for Gonorrhoea and other Sexually Transmitted Infections, National Reference Laboratory for Sexually Transmitted Infections, Department of Laboratory Medicine, Clinical Microbiology, Faculty of Medicine and Health, Örebro University, Örebro, Sweden
| | - Simon R Harris
- Microbiotica Ltd, Biodata Innovation Centre, Wellcome Genome Campus, Hinxton, Cambridge, UK.
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Deng C, Naler LB, Lu C. Microfluidic epigenomic mapping technologies for precision medicine. LAB ON A CHIP 2019; 19:2630-2650. [PMID: 31338502 PMCID: PMC6697104 DOI: 10.1039/c9lc00407f] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Epigenomic mapping of tissue samples generates critical insights into genome-wide regulations of gene activities and expressions during normal development and disease processes. Epigenomic profiling using a low number of cells produced by patient and mouse samples presents new challenges to biotechnologists. In this review, we first discuss the rationale and premise behind profiling epigenomes for precision medicine. We then examine the existing literature on applying microfluidics to facilitate low-input and high-throughput epigenomic profiling, with emphasis on technologies enabling interfacing with next-generation sequencing. We detail assays on studies of histone modifications, DNA methylation, 3D chromatin structures and non-coding RNAs. Finally, we discuss what the future may hold in terms of method development and translational potential.
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Affiliation(s)
- Chengyu Deng
- Department of Chemical Engineering, Virginia Tech, Blacksburg, Virginia 24061, USA.
| | - Lynette B Naler
- Department of Chemical Engineering, Virginia Tech, Blacksburg, Virginia 24061, USA.
| | - Chang Lu
- Department of Chemical Engineering, Virginia Tech, Blacksburg, Virginia 24061, USA.
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29
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Jensen TØ, Tellgren-Roth C, Redl S, Maury J, Jacobsen SAB, Pedersen LE, Nielsen AT. Genome-wide systematic identification of methyltransferase recognition and modification patterns. Nat Commun 2019; 10:3311. [PMID: 31427571 PMCID: PMC6700114 DOI: 10.1038/s41467-019-11179-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Accepted: 06/27/2019] [Indexed: 01/25/2023] Open
Abstract
Genome-wide analysis of DNA methylation patterns using single molecule real-time DNA sequencing has boosted the number of publicly available methylomes. However, there is a lack of tools coupling methylation patterns and the corresponding methyltransferase genes. Here we demonstrate a high-throughput method for coupling methyltransferases with their respective motifs, using automated cloning and analysing the methyltransferases in vectors carrying a strain-specific cassette containing all potential target sites. To validate the method, we analyse the genomes of the thermophile Moorella thermoacetica and the mesophile Acetobacterium woodii, two acetogenic bacteria having substantially modified genomes with 12 methylation motifs and a total of 23 methyltransferase genes. Using our method, we characterize the 23 methyltransferases, assign motifs to the respective enzymes and verify activity for 11 of the 12 motifs. Single molecule real-time DNA sequencing allows genome-wide identification of DNA methylation patterns. Here, Jensen et al. present a high-throughput method that allows rapid coupling of DNA methylation patterns with their corresponding methyltransferase genes in bacteria.
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Affiliation(s)
- Torbjørn Ølshøj Jensen
- The Novo Nordisk Foundation Center for Biosustainability (CfB), Technical University of Denmark (DTU), DK-2800, Lyngby, Denmark
| | - Christian Tellgren-Roth
- Uppsala Genome Center, National Genomics Infrastructure, SciLifeLab, SE-751 08, Uppsala, Sweden
| | - Stephanie Redl
- The Novo Nordisk Foundation Center for Biosustainability (CfB), Technical University of Denmark (DTU), DK-2800, Lyngby, Denmark.,Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Jérôme Maury
- The Novo Nordisk Foundation Center for Biosustainability (CfB), Technical University of Denmark (DTU), DK-2800, Lyngby, Denmark
| | | | - Lasse Ebdrup Pedersen
- The Novo Nordisk Foundation Center for Biosustainability (CfB), Technical University of Denmark (DTU), DK-2800, Lyngby, Denmark
| | - Alex Toftgaard Nielsen
- The Novo Nordisk Foundation Center for Biosustainability (CfB), Technical University of Denmark (DTU), DK-2800, Lyngby, Denmark.
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Rational development of transformation in Clostridium thermocellum ATCC 27405 via complete methylome analysis and evasion of native restriction-modification systems. J Ind Microbiol Biotechnol 2019; 46:1435-1443. [PMID: 31342224 PMCID: PMC6791906 DOI: 10.1007/s10295-019-02218-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2019] [Accepted: 07/11/2019] [Indexed: 12/13/2022]
Abstract
A major barrier to both metabolic engineering and fundamental biological studies is the lack of genetic tools in most microorganisms. One example is Clostridium thermocellum ATCC 27405T, where genetic tools are not available to help validate decades of hypotheses. A significant barrier to DNA transformation is restriction–modification systems, which defend against foreign DNA methylated differently than the host. To determine the active restriction–modification systems in this strain, we performed complete methylome analysis via single-molecule, real-time sequencing to detect 6-methyladenine and 4-methylcytosine and the rarely used whole-genome bisulfite sequencing to detect 5-methylcytosine. Multiple active systems were identified, and corresponding DNA methyltransferases were expressed from the Escherichia coli chromosome to mimic the C. thermocellum methylome. Plasmid methylation was experimentally validated and successfully electroporated into C. thermocellum ATCC 27405. This combined approach enabled genetic modification of the C. thermocellum-type strain and acts as a blueprint for transformation of other non-model microorganisms.
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31
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Beaulaurier J, Schadt EE, Fang G. Deciphering bacterial epigenomes using modern sequencing technologies. Nat Rev Genet 2019; 20:157-172. [PMID: 30546107 DOI: 10.1038/s41576-018-0081-3] [Citation(s) in RCA: 99] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Prokaryotic DNA contains three types of methylation: N6-methyladenine, N4-methylcytosine and 5-methylcytosine. The lack of tools to analyse the frequency and distribution of methylated residues in bacterial genomes has prevented a full understanding of their functions. Now, advances in DNA sequencing technology, including single-molecule, real-time sequencing and nanopore-based sequencing, have provided new opportunities for systematic detection of all three forms of methylated DNA at a genome-wide scale and offer unprecedented opportunities for achieving a more complete understanding of bacterial epigenomes. Indeed, as the number of mapped bacterial methylomes approaches 2,000, increasing evidence supports roles for methylation in regulation of gene expression, virulence and pathogen-host interactions.
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Affiliation(s)
- John Beaulaurier
- Department of Genetics and Genomic Sciences and Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Eric E Schadt
- Department of Genetics and Genomic Sciences and Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Gang Fang
- Department of Genetics and Genomic Sciences and Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
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32
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Abstract
5-Formyl-2'-deoxycytidine (5fdC) is a naturally occurring nucleobase that is broadly distributed in genomic DNA. 5fdC is produced via the oxidation of 5-methylcytosine (5mdC) by ten-eleven translocation enzyme (TET) and can be further converted to 5-carboxylcytosine (5cadC) by TET. Both 5fdC and 5cadC can be restored to dC by TDG-mediated base excision repair and direct deformylation/decarboxylation. Thus, 5fdC is considered an intermediate in the TET-mediated DNA demethylation pathway. 5fdC also alters the structure and stability of genomic DNA and affects genetic expression. This review summarizes the recent research on 5fdC, detailing its formation, detection and distribution, biological functions and transformation in cells. The challenges and future prospects to further explore the function and metabolism of 5fdC are briefly discussed at the end.
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Affiliation(s)
- Yingqian Zhang
- State Key Laboratory of Elemento-Organic Chemistry and Department of Chemical Biology, College of Chemistry, Nankai University, Tianjin, 300071, China
| | - Chuanzheng Zhou
- State Key Laboratory of Elemento-Organic Chemistry and Department of Chemical Biology, College of Chemistry, Nankai University, Tianjin, 300071, China.
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33
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Detection of DNA base modifications by deep recurrent neural network on Oxford Nanopore sequencing data. Nat Commun 2019; 10:2449. [PMID: 31164644 PMCID: PMC6547721 DOI: 10.1038/s41467-019-10168-2] [Citation(s) in RCA: 161] [Impact Index Per Article: 32.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Accepted: 04/25/2019] [Indexed: 02/06/2023] Open
Abstract
DNA base modifications, such as C5-methylcytosine (5mC) and N6-methyldeoxyadenosine (6mA), are important types of epigenetic regulations. Short-read bisulfite sequencing and long-read PacBio sequencing have inherent limitations to detect DNA modifications. Here, using raw electric signals of Oxford Nanopore long-read sequencing data, we design DeepMod, a bidirectional recurrent neural network (RNN) with long short-term memory (LSTM) to detect DNA modifications. We sequence a human genome HX1 and a Chlamydomonas reinhardtii genome using Nanopore sequencing, and then evaluate DeepMod on three types of genomes (Escherichia coli, Chlamydomonas reinhardtii and human genomes). For 5mC detection, DeepMod achieves average precision up to 0.99 for both synthetically introduced and naturally occurring modifications. For 6mA detection, DeepMod achieves ~0.9 average precision on Escherichia coli data, and have improved performance than existing methods on Chlamydomonas reinhardtii data. In conclusion, DeepMod performs well for genome-scale detection of DNA modifications and will facilitate epigenetic analysis on diverse species. DNA modification generates unique electric signals in Oxford Nanopore sequencing data but the signals can be complicated to decipher. Here, the authors develop a deep learning framework, DeepMod, to detect DNA base modifications including 5mC and 6mA using Nanopore sequencing data
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34
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O'Brown ZK, Boulias K, Wang J, Wang SY, O'Brown NM, Hao Z, Shibuya H, Fady PE, Shi Y, He C, Megason SG, Liu T, Greer EL. Sources of artifact in measurements of 6mA and 4mC abundance in eukaryotic genomic DNA. BMC Genomics 2019; 20:445. [PMID: 31159718 PMCID: PMC6547475 DOI: 10.1186/s12864-019-5754-6] [Citation(s) in RCA: 90] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Accepted: 04/30/2019] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Directed DNA methylation on N6-adenine (6mA), N4-cytosine (4mC), and C5-cytosine (5mC) can potentially increase DNA coding capacity and regulate a variety of biological functions. These modifications are relatively abundant in bacteria, occurring in about a percent of all bases of most bacteria. Until recently, 5mC and its oxidized derivatives were thought to be the only directed DNA methylation events in metazoa. New and more sensitive detection techniques (ultra-high performance liquid chromatography coupled with mass spectrometry (UHPLC-ms/ms) and single molecule real-time sequencing (SMRTseq)) have suggested that 6mA and 4mC modifications could be present in a variety of metazoa. RESULTS Here, we find that both of these techniques are prone to inaccuracies, which overestimate DNA methylation concentrations in metazoan genomic DNA. Artifacts can arise from methylated bacterial DNA contamination of enzyme preparations used to digest DNA and contaminating bacterial DNA in eukaryotic DNA preparations. Moreover, DNA sonication introduces a novel modified base from 5mC that has a retention time near 4mC that can be confused with 4mC. Our analyses also suggest that SMRTseq systematically overestimates 4mC in prokaryotic and eukaryotic DNA and 6mA in DNA samples in which it is rare. Using UHPLC-ms/ms designed to minimize and subtract artifacts, we find low to undetectable levels of 4mC and 6mA in genomes of representative worms, insects, amphibians, birds, rodents and primates under normal growth conditions. We also find that mammalian cells incorporate exogenous methylated nucleosides into their genome, suggesting that a portion of 6mA modifications could derive from incorporation of nucleosides from bacteria in food or microbiota. However, gDNA samples from gnotobiotic mouse tissues found rare (0.9-3.7 ppm) 6mA modifications above background. CONCLUSIONS Altogether these data demonstrate that 6mA and 4mC are rarer in metazoa than previously reported, and highlight the importance of careful sample preparation and measurement, and need for more accurate sequencing techniques.
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Affiliation(s)
- Zach K O'Brown
- Division of Newborn Medicine, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA.,Department of Pediatrics, Harvard Medical School, Boston, MA, 02115, USA
| | - Konstantinos Boulias
- Division of Newborn Medicine, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA.,Department of Pediatrics, Harvard Medical School, Boston, MA, 02115, USA
| | - Jie Wang
- Department of Biochemistry and Biostatistics, University at Buffalo Center of Excellence in Bioinformatics & Life Sciences, Buffalo, NY, 14203, USA
| | - Simon Yuan Wang
- Division of Newborn Medicine, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA.,Department of Pediatrics, Harvard Medical School, Boston, MA, 02115, USA
| | - Natasha M O'Brown
- Department of Neurobiology, Harvard Medical School, Boston, MA, 02115, USA
| | - Ziyang Hao
- Department of Chemistry and Howard Hughes Medical Institute, The University of Chicago, Chicago, IL, 60637, USA
| | - Hiroki Shibuya
- Division of Newborn Medicine, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA.,Department of Pediatrics, Harvard Medical School, Boston, MA, 02115, USA.,Present address: Department of Chemistry and Molecular Biology, University of Gothenburg, SE-40530, Gothenburg, Sweden
| | - Paul-Enguerrand Fady
- Division of Newborn Medicine, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA
| | - Yang Shi
- Division of Newborn Medicine, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA.,Department of Cell Biology, Harvard Medical School, Boston, MA, 02115, USA
| | - Chuan He
- Department of Chemistry and Howard Hughes Medical Institute, The University of Chicago, Chicago, IL, 60637, USA
| | - Sean G Megason
- Department of Systems Biology, Harvard Medical School, Boston, MA, 02115, USA
| | - Tao Liu
- Department of Biochemistry and Biostatistics, University at Buffalo Center of Excellence in Bioinformatics & Life Sciences, Buffalo, NY, 14203, USA
| | - Eric L Greer
- Division of Newborn Medicine, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA. .,Department of Pediatrics, Harvard Medical School, Boston, MA, 02115, USA.
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35
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Zeng H, He B, Yi C. Compilation of Modern Technologies To Map Genome-Wide Cytosine Modifications in DNA. Chembiochem 2019; 20:1898-1905. [PMID: 30809902 DOI: 10.1002/cbic.201900035] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2019] [Indexed: 12/19/2022]
Abstract
Over the past few decades, various DNA modification detection methods have been developed; many of the high-resolution methods are based on bisulfite treatment, which leads to DNA degradation, to a degree. Thus, novel bisulfite-free approaches have been developed in recent years and shown to be useful for epigenome analysis in otherwise difficult-to-handle, but important, DNA samples, such as hmC-seal and hmC-CATCH. Herein, an overview of advances in the development of epigenome sequencing methods for these important DNA modifications is provided.
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Affiliation(s)
- Hu Zeng
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Department of Chemical Biology and, Synthetic and Functional Biomolecules Center, College of Chemistry and Molecular Engineering and, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, P. R. China
| | - Bo He
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Department of Chemical Biology and, Synthetic and Functional Biomolecules Center, College of Chemistry and Molecular Engineering and, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, P. R. China
| | - Chengqi Yi
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Department of Chemical Biology and, Synthetic and Functional Biomolecules Center, College of Chemistry and Molecular Engineering and, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, P. R. China
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36
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Liu Q, Georgieva DC, Egli D, Wang K. NanoMod: a computational tool to detect DNA modifications using Nanopore long-read sequencing data. BMC Genomics 2019; 20:78. [PMID: 30712508 PMCID: PMC6360650 DOI: 10.1186/s12864-018-5372-8] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Recent advances in single-molecule sequencing techniques, such as Nanopore sequencing, improved read length, increased sequencing throughput, and enabled direct detection of DNA modifications through the analysis of raw signals. These DNA modifications include naturally occurring modifications such as DNA methylations, as well as modifications that are introduced by DNA damage or through synthetic modifications to one of the four standard nucleotides. METHODS To improve the performance of detecting DNA modifications, especially synthetically introduced modifications, we developed a novel computational tool called NanoMod. NanoMod takes raw signal data on a pair of DNA samples with and without modified bases, extracts signal intensities, performs base error correction based on a reference sequence, and then identifies bases with modifications by comparing the distribution of raw signals between two samples, while taking into account of the effects of neighboring bases on modified bases ("neighborhood effects"). RESULTS We evaluated NanoMod on simulation data sets, based on different types of modifications and different magnitudes of neighborhood effects, and found that NanoMod outperformed other methods in identifying known modified bases. Additionally, we demonstrated superior performance of NanoMod on an E. coli data set with 5mC (5-methylcytosine) modifications. CONCLUSIONS In summary, NanoMod is a flexible tool to detect DNA modifications with single-base resolution from raw signals in Nanopore sequencing, and will facilitate large-scale functional genomics experiments that use modified nucleotides.
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Affiliation(s)
- Qian Liu
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, Children’s Hospital of Philadelphia, Philadelphia, PA 19104 USA
| | - Daniela C. Georgieva
- Integrated Program in Cellular, Molecular, and Biomedical Studies, Columbia University, New York, NY 10032 USA
| | - Dieter Egli
- Department of Pediatrics, Columbia University, New York, NY 10032 USA
| | - Kai Wang
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, Children’s Hospital of Philadelphia, Philadelphia, PA 19104 USA
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104 USA
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37
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McIntyre ABR, Alexander N, Grigorev K, Bezdan D, Sichtig H, Chiu CY, Mason CE. Single-molecule sequencing detection of N6-methyladenine in microbial reference materials. Nat Commun 2019; 10:579. [PMID: 30718479 PMCID: PMC6362088 DOI: 10.1038/s41467-019-08289-9] [Citation(s) in RCA: 89] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 12/19/2018] [Indexed: 11/17/2022] Open
Abstract
The DNA base modification N6-methyladenine (m6A) is involved in many pathways related to the survival of bacteria and their interactions with hosts. Nanopore sequencing offers a new, portable method to detect base modifications. Here, we show that a neural network can improve m6A detection at trained sequence contexts compared to previously published methods using deviations between measured and expected current values as each adenine travels through a pore. The model, implemented as the mCaller software package, can be extended to detect known or confirm suspected methyltransferase target motifs based on predictions of methylation at untrained contexts. We use PacBio, Oxford Nanopore, methylated DNA immunoprecipitation sequencing (MeDIP-seq), and whole-genome bisulfite sequencing data to generate and orthogonally validate methylomes for eight microbial reference species. These well-characterized microbial references can serve as controls in the development and evaluation of future methods for the identification of base modifications from single-molecule sequencing data.
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Affiliation(s)
- Alexa B R McIntyre
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, 10065, NY, USA
- Tri-Institutional Training Program in Computational Biology and Medicine, New York, 10065, NY, USA
| | - Noah Alexander
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, 10065, NY, USA
| | - Kirill Grigorev
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, 10065, NY, USA
| | - Daniela Bezdan
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, 10065, NY, USA
| | - Heike Sichtig
- US Food and Drug Administration, Silver Spring, 20993, MD, USA
| | - Charles Y Chiu
- Department of Laboratory Medicine, University of California San Francisco, San Francisco, 94107, CA, USA
- UCSF-Abbott Viral Diagnostics and Discovery Center, San Francisco, 94107, CA, USA
| | - Christopher E Mason
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, 10065, NY, USA.
- The HRH Prince Alwaleed Bin Talal Bin Abdulaziz Alsaud Institute for Computational Biomedicine, Weill Cornell Medicine, New York, 10021, NY, USA.
- The Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, 10021, NY, USA.
- The WorldQuant Initiative for Quantitative Prediction, Weill Cornell Medicine, New York, 10021, NY, USA.
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Study of the whole genome, methylome and transcriptome of Cordyceps militaris. Sci Rep 2019; 9:898. [PMID: 30696919 PMCID: PMC6351555 DOI: 10.1038/s41598-018-38021-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 12/19/2018] [Indexed: 12/21/2022] Open
Abstract
The complete genome of Cordyceps militaris was sequenced using single-molecule real-time (SMRT) sequencing technology at a coverage over 300×. The genome size was 32.57 Mb, and 14 contigs ranging from 0.35 to 4.58 Mb with an N50 of 2.86 Mb were assembled, including 4 contigs with telomeric sequences on both ends and an additional 8 contigs with telomeric sequences on either the 5′ or 3′ end. A methylome database of the genome was constructed using SMRT and m4C and m6A methylated nucleotides, and many unknown modification types were identified. The major m6A methylation motif is GA and GGAG, and the major m4C methylation motif is GC or CG/GC. In the C. militaris genome DNA, there were four types of methylated nucleotides that we confirmed using high-resolution LCMS-IT-TOF. Using PacBio Iso-Seq, a total of 31,133 complete cDNA sequences were obtained in the fruiting body. The conserved domains of the nontranscribed regions of the genome include TATA boxes, which are the initial regions of genome replication. There were 406 structural variants between the HN and CM01 strains, and there were 1,114 structural variants between the HN and ATCC strains.
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39
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Parker MJ, Weigele PR, Saleh L. Insights into the Biochemistry, Evolution, and Biotechnological Applications of the Ten-Eleven Translocation (TET) Enzymes. Biochemistry 2019; 58:450-467. [PMID: 30571101 DOI: 10.1021/acs.biochem.8b01185] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
A tight link exists between patterns of DNA methylation at carbon 5 of cytosine and differential gene expression in mammalian tissues. Indeed, aberrant DNA methylation results in various human diseases, including neurologic and immune disorders, and contributes to the initiation and progression of various cancers. Proper DNA methylation depends on the fidelity and control of the underlying mechanisms that write, maintain, and erase these epigenetic marks. In this Perspective, we address one of the key players in active demethylation: the ten-eleven translocation enzymes or TETs. These enzymes belong to the Fe2+/α-ketoglutarate-dependent dioxygenase superfamily and iteratively oxidize 5-methylcytosine (5mC) in DNA to produce 5-hydroxymethylcytosine, 5-formylcytosine, and 5-carboxycytosine. The latter three bases may convey additional layers of epigenetic information in addition to being intermediates in active demethylation. Despite the intense interest in understanding the physiological roles TETs play in active demethylation and cell regulation, less has been done, in comparison, to illuminate details of the chemistry and factors involved in regulating the three-step oxidation mechanism. Herein, we focus on what is known about the biochemical features of TETs and explore questions whose answers will lead to a more detailed understanding of the in vivo modus operandi of these enzymes. We also summarize the membership and evolutionary history of the TET/JBP family and highlight the prokaryotic homologues as a reservoir of potentially diverse functionalities awaiting discovery. Finally, we spotlight sequencing methods that utilize TETs for mapping 5mC and its oxidation products in genomic DNA and comment on possible improvements in these approaches.
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Affiliation(s)
- Mackenzie J Parker
- Research Department , New England Biolabs, Inc. , 240 County Road , Ipswich , Massachusetts 01938 , United States
| | - Peter R Weigele
- Research Department , New England Biolabs, Inc. , 240 County Road , Ipswich , Massachusetts 01938 , United States
| | - Lana Saleh
- Research Department , New England Biolabs, Inc. , 240 County Road , Ipswich , Massachusetts 01938 , United States
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Asenso J, Wang L, Du Y, Liu QH, Xu BJ, Guo MZ, Tang DQ. Advances in detection and quantification of methylcytosine and its derivatives. J Sep Sci 2018; 42:1105-1116. [PMID: 30575277 DOI: 10.1002/jssc.201801100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2018] [Revised: 11/21/2018] [Accepted: 12/16/2018] [Indexed: 11/08/2022]
Abstract
Methylation of the fifth carbon atom in cytosine is an epigenetic modification of deoxyribonucleic acid that plays important roles in numerous cellular processes and disease pathogenesis. Three additional states of cytosine, that is, 5-hydroxymethylcytosine, 5-formylcytosine and 5-carboxylcytosine, have been identified and associated with the diagnosis and/or prognosis of diseases. However, accurate measurement of those intermediates is a challenge since their global levels are relatively low. A number of innovative methods have been developed to detect and quantify these compounds in biological samples, such as blood, tissue and urine, etc. This review focuses on recent advancement in detection and quantification of four cytosine modifications, based on which, the development, diagnosis, and prognosis of diseases could be monitored through non-invasive procedures.
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Affiliation(s)
- James Asenso
- Key Laboratory of New Drug Research and Clinical Pharmacy of Jiangsu Province, School of Pharmacy, Xuzhou Medical University, Xuzhou, P. R. China
| | - Liang Wang
- Department of Bioinformatics, School of Medical Informatics, Xuzhou Medical University, Xuzhou, P. R. China
| | - Yan Du
- Key Laboratory of New Drug Research and Clinical Pharmacy of Jiangsu Province, School of Pharmacy, Xuzhou Medical University, Xuzhou, P. R. China.,Department of Pharmaceutical Analysis, School of Pharmacy, Xuzhou Medical University, Xuzhou, P. R. China
| | - Qing-Hua Liu
- Key Laboratory of New Drug Research and Clinical Pharmacy of Jiangsu Province, School of Pharmacy, Xuzhou Medical University, Xuzhou, P. R. China
| | - Bing-Ju Xu
- Key Laboratory of New Drug Research and Clinical Pharmacy of Jiangsu Province, School of Pharmacy, Xuzhou Medical University, Xuzhou, P. R. China
| | - Meng-Zhe Guo
- Key Laboratory of New Drug Research and Clinical Pharmacy of Jiangsu Province, School of Pharmacy, Xuzhou Medical University, Xuzhou, P. R. China.,Department of Pharmaceutical Analysis, School of Pharmacy, Xuzhou Medical University, Xuzhou, P. R. China
| | - Dao-Quan Tang
- Key Laboratory of New Drug Research and Clinical Pharmacy of Jiangsu Province, School of Pharmacy, Xuzhou Medical University, Xuzhou, P. R. China.,Department of Pharmaceutical Analysis, School of Pharmacy, Xuzhou Medical University, Xuzhou, P. R. China
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A sensitive fluorometric DNA nanobiosensor based on a new fluorophore for tumor suppressor gene detection. Talanta 2018; 190:140-146. [DOI: 10.1016/j.talanta.2018.07.042] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 07/11/2018] [Accepted: 07/12/2018] [Indexed: 12/13/2022]
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42
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Kelleher P, Murphy J, Mahony J, van Sinderen D. Identification of DNA Base Modifications by Means of Pacific Biosciences RS Sequencing Technology. Methods Mol Biol 2018; 1681:127-137. [PMID: 29134592 DOI: 10.1007/978-1-4939-7343-9_10] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Whole phage genomes can be sequenced readily using one or a combination of next generation sequencing (NGS) technologies. One of the most recently developed NGS platforms, the so-called Single-Molecule Real-Time (SMRT) sequencing approach provided by the PacBio RS platform, is particularly useful in providing complete (i.e., un-gapped) genome sequences, but differs from other technologies in that the platform also allows for downstream analysis to identify nucleotides that have been modified by DNA methylation. Here, we describe the methodological approach for the detection of genomic methylation motifs by means of SMRT sequencing.
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Affiliation(s)
- Philip Kelleher
- School of Microbiology, University College Cork, Cork, Ireland
| | - James Murphy
- School of Microbiology, University College Cork, Cork, Ireland
| | - Jennifer Mahony
- School of Microbiology, University College Cork, Cork, Ireland.,Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland
| | - Douwe van Sinderen
- School of Microbiology, University College Cork, Cork, Ireland. .,Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland.
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Liu L, Zhang Y, Jiang D, Du S, Deng Z, Wang L, Chen S. Recent Advances in the Genomic Profiling of Bacterial Epigenetic Modifications. Biotechnol J 2018; 14:e1800001. [PMID: 29878585 DOI: 10.1002/biot.201800001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 06/03/2018] [Indexed: 01/21/2023]
Affiliation(s)
- Liqiong Liu
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery; Ministry of Education; School of Pharmaceutical Sciences; Zhongnan Hospital; Wuhan University; Wuhan 430071 China
- Taihe Hospital; Hubei University of Medicine; Shiyan 442000 Hubei China
| | - Yizhou Zhang
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery; Ministry of Education; School of Pharmaceutical Sciences; Zhongnan Hospital; Wuhan University; Wuhan 430071 China
| | - Dongxu Jiang
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery; Ministry of Education; School of Pharmaceutical Sciences; Zhongnan Hospital; Wuhan University; Wuhan 430071 China
- Taihe Hospital; Hubei University of Medicine; Shiyan 442000 Hubei China
| | - Shiming Du
- Taihe Hospital; Hubei University of Medicine; Shiyan 442000 Hubei China
| | - Zixin Deng
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery; Ministry of Education; School of Pharmaceutical Sciences; Zhongnan Hospital; Wuhan University; Wuhan 430071 China
- State Key Laboratory of Microbial Metabolism; School of Life Sciences and Biotechnology; Shanghai Jiao Tong University; Shanghai 200240 China
| | - Lianrong Wang
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery; Ministry of Education; School of Pharmaceutical Sciences; Zhongnan Hospital; Wuhan University; Wuhan 430071 China
| | - Shi Chen
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery; Ministry of Education; School of Pharmaceutical Sciences; Zhongnan Hospital; Wuhan University; Wuhan 430071 China
- Taihe Hospital; Hubei University of Medicine; Shiyan 442000 Hubei China
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Dietzsch J, Feineis D, Höbartner C. Chemoselective labeling and site-specific mapping of 5-formylcytosine as a cellular nucleic acid modification. FEBS Lett 2018; 592:2032-2047. [DOI: 10.1002/1873-3468.13058] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 04/11/2018] [Accepted: 04/13/2018] [Indexed: 01/14/2023]
Affiliation(s)
- Julia Dietzsch
- Institute of Organic Chemistry; University of Würzburg; Germany
| | - Doris Feineis
- Institute of Organic Chemistry; University of Würzburg; Germany
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Schiefelbein SHH, Kamal A, She Z, Rentmeister A, Kraatz HB. Direct Bisulfite-Free Detection of 5-Methylcytosine by Using Electrochemical Measurements Aided by a Monoclonal Antibody. ChemElectroChem 2018. [DOI: 10.1002/celc.201800324] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Stephan H. H. Schiefelbein
- University of Muenster; Department of Chemistry; Institute of Biochemistry; Wilhelm-Klemm-Straße 2, D- 48149 Münster Germany
| | - Ajar Kamal
- Department of Physical and Environmental Sciences; University of Toronto Scarborough; 1265 Military Trail Toronto ON M1C 1 A4 Canada
| | - Zhe She
- Department of Physical and Environmental Sciences; University of Toronto Scarborough; 1265 Military Trail Toronto ON M1C 1 A4 Canada
| | - Andrea Rentmeister
- University of Muenster; Department of Chemistry; Institute of Biochemistry; Wilhelm-Klemm-Straße 2, D- 48149 Münster Germany
- Cells-in-Motion Cluster of Excellence (EXC 1003-CiM); University of Muenster; Germany
| | - Heinz-Bernhard Kraatz
- Department of Physical and Environmental Sciences; University of Toronto Scarborough; 1265 Military Trail Toronto ON M1C 1 A4 Canada
- Department of Chemistry; University of Toronto; 80 St. George Street Toronto ON M5S 3H6 Canada
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Patakova P, Kolek J, Sedlar K, Koscova P, Branska B, Kupkova K, Paulova L, Provaznik I. Comparative analysis of high butanol tolerance and production in clostridia. Biotechnol Adv 2018; 36:721-738. [DOI: 10.1016/j.biotechadv.2017.12.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 12/05/2017] [Accepted: 12/12/2017] [Indexed: 12/24/2022]
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Chen Y, Hong T, Wang S, Mo J, Tian T, Zhou X. Epigenetic modification of nucleic acids: from basic studies to medical applications. Chem Soc Rev 2018; 46:2844-2872. [PMID: 28352906 DOI: 10.1039/c6cs00599c] [Citation(s) in RCA: 127] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The epigenetic modification of nucleic acids represents one of the most significant areas of study in the field of nucleic acids because it makes gene regulation more complex and heredity more complicated, thus indicating its profound impact on aspects of heredity, growth, and diseases. The recent characterization of epigenetic modifications of DNA and RNA using chemical labelling strategies has promoted the discovery of these modifications, and the newly developed single-base or single-cell resolution mapping strategies have enabled large-scale epigenetic studies in eukaryotes. Due to these technological breakthroughs, several new epigenetic marks have been discovered that have greatly extended the scope and impact of epigenetic modifications in nucleic acids over the past few years. Because epigenetics is reversible and susceptible to environmental factors, it could potentially be a promising direction for clinical medicine research. In this review, we have comprehensively discussed how these epigenetic marks are involved in disease, including the pathogenesis, prevention, diagnosis and treatment of disease. These findings have revealed that the epigenetic modification of nucleic acids has considerable significance in various areas from methodology to clinical medicine and even in biomedical applications.
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Affiliation(s)
- Yuqi Chen
- College of Chemistry and Molecular Sciences, Institute of Advanced Studies, Key Laboratory of Biomedical Polymers of Ministry of Education, Hubei Province Key Laboratory of Allergy and Immunology, Wuhan University, Hubei, Wuhan 430072, P. R. China.
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Resolving the complete genome of Kuenenia stuttgartiensis from a membrane bioreactor enrichment using Single-Molecule Real-Time sequencing. Sci Rep 2018; 8:4580. [PMID: 29545612 PMCID: PMC5854607 DOI: 10.1038/s41598-018-23053-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Accepted: 03/06/2018] [Indexed: 11/30/2022] Open
Abstract
Anaerobic ammonium-oxidizing (anammox) bacteria are a group of strictly anaerobic chemolithoautotrophic microorganisms. They are capable of oxidizing ammonium to nitrogen gas using nitrite as a terminal electron acceptor, thereby facilitating the release of fixed nitrogen into the atmosphere. The anammox process is thought to exert a profound impact on the global nitrogen cycle and has been harnessed as an environment-friendly method for nitrogen removal from wastewater. In this study, we present the first closed genome sequence of an anammox bacterium, Kuenenia stuttgartiensis MBR1. It was obtained through Single-Molecule Real-Time (SMRT) sequencing of an enrichment culture constituting a mixture of at least two highly similar Kuenenia strains. The genome of the novel MBR1 strain is different from the previously reported Kuenenia KUST reference genome as it contains numerous structural variations and unique genomic regions. We find new proteins, such as a type 3b (sulf)hydrogenase and an additional copy of the hydrazine synthase gene cluster. Moreover, multiple copies of ammonium transporters and proteins regulating nitrogen uptake were identified, suggesting functional differences in metabolism. This assembly, including the genome-wide methylation profile, provides a new foundation for comparative and functional studies aiming to elucidate the biochemical and metabolic processes of these organisms.
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Ouellette M, Gogarten JP, Lajoie J, Makkay AM, Papke RT. Characterizing the DNA Methyltransferases of Haloferax volcanii via Bioinformatics, Gene Deletion, and SMRT Sequencing. Genes (Basel) 2018; 9:genes9030129. [PMID: 29495512 PMCID: PMC5867850 DOI: 10.3390/genes9030129] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 02/16/2018] [Accepted: 02/19/2018] [Indexed: 12/31/2022] Open
Abstract
DNA methyltransferases (MTases), which catalyze the methylation of adenine and cytosine bases in DNA, can occur in bacteria and archaea alongside cognate restriction endonucleases (REases) in restriction-modification (RM) systems or independently as orphan MTases. Although DNA methylation and MTases have been well-characterized in bacteria, research into archaeal MTases has been limited. A previous study examined the genomic DNA methylation patterns (methylome) of the halophilic archaeon Haloferax volcanii, a model archaeal system which can be easily manipulated in laboratory settings, via single-molecule real-time (SMRT) sequencing and deletion of a putative MTase gene (HVO_A0006). In this follow-up study, we deleted other putative MTase genes in H. volcanii and sequenced the methylomes of the resulting deletion mutants via SMRT sequencing to characterize the genes responsible for DNA methylation. The results indicate that deletion of putative RM genes HVO_0794, HVO_A0006, and HVO_A0237 in a single strain abolished methylation of the sole cytosine motif in the genome (Cm4TAG). Amino acid alignments demonstrated that HVO_0794 shares homology with characterized cytosine CTAG MTases in other organisms, indicating that this MTase is responsible for Cm4TAG methylation in H. volcanii. The CTAG motif has high density at only one of the origins of replication, and there is no relative increase in CTAG motif frequency in the genome of H. volcanii, indicating that CTAG methylation might not have effectively taken over the role of regulating DNA replication and mismatch repair in the organism as previously predicted. Deletion of the putative Type I RM operon rmeRMS (HVO_2269-2271) resulted in abolished methylation of the adenine motif in the genome (GCAm6BN₆VTGC). Alignments of the MTase (HVO_2270) and site specificity subunit (HVO_2271) demonstrate homology with other characterized Type I MTases and site specificity subunits, indicating that the rmeRMS operon is responsible for adenine methylation in H. volcanii. Together with HVO_0794, these genes appear to be responsible for all detected methylation in H. volcanii, even though other putative MTases (HVO_C0040, HVO_A0079) share homology with characterized MTases in other organisms. We also report the construction of a multi-RM deletion mutant (ΔRM), with multiple RM genes deleted and with no methylation detected via SMRT sequencing, which we anticipate will be useful for future studies on DNA methylation in H. volcanii.
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Affiliation(s)
- Matthew Ouellette
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06268, USA.
| | - J Peter Gogarten
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06268, USA.
| | - Jessica Lajoie
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06268, USA.
| | - Andrea M Makkay
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06268, USA.
| | - R Thane Papke
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06268, USA.
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