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Takahashi S, Oshige M, Katsura S. DNA Manipulation and Single-Molecule Imaging. Molecules 2021; 26:1050. [PMID: 33671359 PMCID: PMC7922115 DOI: 10.3390/molecules26041050] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 02/12/2021] [Accepted: 02/14/2021] [Indexed: 11/22/2022] Open
Abstract
DNA replication, repair, and recombination in the cell play a significant role in the regulation of the inheritance, maintenance, and transfer of genetic information. To elucidate the biomolecular mechanism in the cell, some molecular models of DNA replication, repair, and recombination have been proposed. These biological studies have been conducted using bulk assays, such as gel electrophoresis. Because in bulk assays, several millions of biomolecules are subjected to analysis, the results of the biological analysis only reveal the average behavior of a large number of biomolecules. Therefore, revealing the elementary biological processes of a protein acting on DNA (e.g., the binding of protein to DNA, DNA synthesis, the pause of DNA synthesis, and the release of protein from DNA) is difficult. Single-molecule imaging allows the analysis of the dynamic behaviors of individual biomolecules that are hidden during bulk experiments. Thus, the methods for single-molecule imaging have provided new insights into almost all of the aspects of the elementary processes of DNA replication, repair, and recombination. However, in an aqueous solution, DNA molecules are in a randomly coiled state. Thus, the manipulation of the physical form of the single DNA molecules is important. In this review, we provide an overview of the unique studies on DNA manipulation and single-molecule imaging to analyze the dynamic interaction between DNA and protein.
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Affiliation(s)
- Shunsuke Takahashi
- Division of Life Science and Engineering, School of Science and Engineering, Tokyo Denki University, Hatoyama-cho, Hiki-gun, Saitama 350-0394, Japan;
| | - Masahiko Oshige
- Department of Environmental Engineering Science, Graduate School of Science and Technology, Gunma University, Kiryu, Gunma 376-8515, Japan;
- Gunma University Center for Food Science and Wellness (GUCFW), Maebashi, Gunma 371-8510, Japan
| | - Shinji Katsura
- Department of Environmental Engineering Science, Graduate School of Science and Technology, Gunma University, Kiryu, Gunma 376-8515, Japan;
- Gunma University Center for Food Science and Wellness (GUCFW), Maebashi, Gunma 371-8510, Japan
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2
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Yuan Y, Chung CYL, Chan TF. Advances in optical mapping for genomic research. Comput Struct Biotechnol J 2020; 18:2051-2062. [PMID: 32802277 PMCID: PMC7419273 DOI: 10.1016/j.csbj.2020.07.018] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Revised: 07/08/2020] [Accepted: 07/24/2020] [Indexed: 12/28/2022] Open
Abstract
Recent advances in optical mapping have allowed the construction of improved genome assemblies with greater contiguity. Optical mapping also enables genome comparison and identification of large-scale structural variations. Association of these large-scale genomic features with biological functions is an important goal in plant and animal breeding and in medical research. Optical mapping has also been used in microbiology and still plays an important role in strain typing and epidemiological studies. Here, we review the development of optical mapping in recent decades to illustrate its importance in genomic research. We detail its applications and algorithms to show its specific advantages. Finally, we discuss the challenges required to facilitate the optimization of optical mapping and improve its future development and application.
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Key Words
- 3D, three-dimensional
- DBG, de Bruijn graph
- DLS, direct label and strain
- DNA, deoxyribonucleic acid
- Genome assembly
- Hi-C, high-throughput chromosome conformation capture
- Mb, million base pair
- Next generation sequencing
- OLC, overlap-layout-consensus
- Optical mapping
- PCR, polymerase chain reaction
- PacBio, Pacific Biosciences
- SRS, short-read sequencing
- SV, structural variation
- Structural variation
- bp, base pair
- kb, kilobase pair
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Affiliation(s)
- Yuxuan Yuan
- School of Life Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China
- State Key Laboratory for Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong SAR, China
- AoE Centre for Genomic Studies on Plant-Environment Interaction for Sustainable Agriculture and Food Security, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Claire Yik-Lok Chung
- School of Life Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China
- State Key Laboratory for Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Ting-Fung Chan
- School of Life Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China
- State Key Laboratory for Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong SAR, China
- AoE Centre for Genomic Studies on Plant-Environment Interaction for Sustainable Agriculture and Food Security, The Chinese University of Hong Kong, Hong Kong SAR, China
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3
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Giani AM, Gallo GR, Gianfranceschi L, Formenti G. Long walk to genomics: History and current approaches to genome sequencing and assembly. Comput Struct Biotechnol J 2019; 18:9-19. [PMID: 31890139 PMCID: PMC6926122 DOI: 10.1016/j.csbj.2019.11.002] [Citation(s) in RCA: 109] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 11/03/2019] [Accepted: 11/06/2019] [Indexed: 12/13/2022] Open
Abstract
Genomes represent the starting point of genetic studies. Since the discovery of DNA structure, scientists have devoted great efforts to determine their sequence in an exact way. In this review we provide a comprehensive historical background of the improvements in DNA sequencing technologies that have accompanied the major milestones in genome sequencing and assembly, ranging from early sequencing methods to Next-Generation Sequencing platforms. We then focus on the advantages and challenges of the current technologies and approaches, collectively known as Third Generation Sequencing. As these technical advancements have been accompanied by progress in analytical methods, we also review the bioinformatic tools currently employed in de novo genome assembly, as well as some applications of Third Generation Sequencing technologies and high-quality reference genomes.
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Key Words
- BAC, Bacterial Artificial Chromosome
- Bioinformatics
- Genome assembly
- HGP, Human Genome Project
- HMW, high molecular weight
- HapMap, haplotype map
- NGS, Next Generation Sequencing
- Next-generation
- OLC, Overlap-Layout-Consensus
- QV, Quality Value (QV)
- Reference
- SBS, Sequencing by Synthesis
- SMRT, Single Molecule Real-Time
- SNPs, Single Nucleotide Polymorphisms
- SRA, Short Read Archive
- SV, Structural Variant
- Sequencing
- TGS, Third Generation Sequencing
- Third-generation
- WGS, Whole Genome Sequencing
- ZMW, Zero-Mode Waveguide
- bp, base pair
- dNTPs, deoxynucleoside triphosphates
- ddNTP, 2,3-dideoxynucleoside triphosphate
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Affiliation(s)
- Alice Maria Giani
- Department of Surgery, Weill Cornell Medical College, New York, NY, USA
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4
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Wu S, Jeffet J, Grunwald A, Sharim H, Gilat N, Torchinsky D, Zheng Q, Zirkin S, Xu L, Ebenstein Y. Microfluidic DNA combing for parallel single-molecule analysis. NANOTECHNOLOGY 2019; 30:045101. [PMID: 30485249 DOI: 10.1088/1361-6528/aaeddc] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
DNA combing is a widely used method for stretching and immobilising DNA molecules on a surface. Fluorescent labelling of genomic information enables high-resolution optical analysis of DNA at the single-molecule level. Despite its simplicity, the application of DNA combing in diagnostic workflows is still limited, mainly due to difficulties in analysing multiple small-volume DNA samples in parallel. Here, we report a simple and versatile microfluidic DNA combing technology (μDC), which allows manipulating, stretching and imaging of multiple, microliter scale DNA samples by employing a manifold of parallel microfluidic channels. Using DNA molecules with repetitive units as molecular rulers, we demonstrate that the μDC technology allows uniform stretching of DNA molecules. The stretching ratio remains consistent along individual molecules as well as between different molecules in the various channels, allowing simultaneous quantitative analysis of different samples loaded into parallel channels. Furthermore, we demonstrate the application of μDC to characterise UVB-induced DNA damage levels in human embryonic kidney cells and the spatial correlation between DNA damage sites. Our results point out the potential application of μDC for quantitative and comparative single-molecule studies of genomic features. The extremely simple design of μDC makes it suitable for integration into other microfluidic platforms to facilitate high-throughput DNA analysis in biological research and medical point-of-care applications.
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Affiliation(s)
- Shuyi Wu
- Center for Nano and Micro Mechanics, School of Aerospace Engineering, Tsinghua University, Beijing, People's Republic of China
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Krerowicz SJ, Hernandez-Ortiz JP, Schwartz DC. Microscale Objects via Restructuring of Large, Double-Stranded DNA Molecules. ACS APPLIED MATERIALS & INTERFACES 2018; 10:41215-41223. [PMID: 30403478 PMCID: PMC6453721 DOI: 10.1021/acsami.8b18157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
As the interest in DNA nanotechnology increases, so does the need for larger and more complex DNA structures. In this work, we describe two methods of using large, double-stranded (ds) DNA to self-assemble sequence-specific, nonrepetitive microscale structures. A model system restructures T7 DNA (40 kb) through sequence-specific biotinylation followed by intramolecular binding to a 40 nm diameter neutravidin bead to create T7 "rosettes". This model system informed the creation of "nodal DNA" where "nodes" with single-stranded DNA flaps are attached to a large dsDNA insert so that a complementary oligonucleotide "strap" bridges the two nodes for restructuring to form a DNA "bolo". To do this in high yield, several methodologies were developed, including a protection/deprotection scheme using RNA/RNase H and dialysis chambers, which remove excess straps while retaining large DNA molecules. To assess these restructuring processes, the DNA was adsorbed onto supported lipid bilayers, allowing for a visual assay of their structure using single-molecule fluorescence microscopy. Good agreement between the expected and observed fluorescence intensity measurements of the individual features of restructured DNA for both the DNA rosettes and bolos gives us a high degree of confidence that both processes give sequence-specific restructuring of large, dsDNA molecules to create microscale objects.
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Affiliation(s)
- Samuel J.W. Krerowicz
- Laboratory for Molecular and Computational Genomics, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
- Laboratory of Genetics, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
- UW Biotechnology Center, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Juan P. Hernandez-Ortiz
- UW Biotechnology Center, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
- Departamento de Materiales y Nanotecnología, Universidad Nacional de Colombia- Medellín, Medellín 050034, Colombia
- Colombia/Wisconsin One-Health Consortium, Universidad Nacional de Colombia- Medellín, Medellín 050034, Colombia
| | - David C. Schwartz
- Laboratory for Molecular and Computational Genomics, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
- Laboratory of Genetics, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
- UW Biotechnology Center, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
- Colombia/Wisconsin One-Health Consortium, Universidad Nacional de Colombia- Medellín, Medellín 050034, Colombia
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Yadav H, Sharma P. A simple and novel DNA combing methodology for Fiber-FISH and optical mapping. Genomics 2018; 111:567-578. [PMID: 29550497 DOI: 10.1016/j.ygeno.2018.03.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Revised: 03/09/2018] [Accepted: 03/12/2018] [Indexed: 02/02/2023]
Abstract
Single molecule analysis can help us study genomics efficiently. It involves studying single DNA molecules for genomic studies. DNA combing is one of such techniques which allowed us to study single DNA molecules for multiple uses. DNA combing technology can be used to perform Fiber-FISH and optical mapping. Physical mapping of genomes can be studied by restriction digestion of combed DNA on glass slides. Restriction fragments can be arranged into optical maps by gathering fluorescent intensity data by CCD camera and image analysis by softwares. Physical mapping and DNA segment rearrangements can be studied by Fiber-FISH which involves application of probes on genomic DNA combed over glass slides. We developed a novel methodology involving combing solution optimization, denatured combed DNA and performed restriction digestion of combed DNA. Thus we provided an efficient and robust combing platform for its application in Fiber-FISH and optical mapping.
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Affiliation(s)
- Hemendra Yadav
- Department of Botany, University of Rajasthan, Jaipur, India.
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7
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Maschmann A, Masters C, Davison M, Lallman J, Thompson D, Kounovsky-Shafer KL. Determining if DNA Stained with a Cyanine Dye Can Be Digested with Restriction Enzymes. J Vis Exp 2018. [PMID: 29443093 DOI: 10.3791/57141] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Visualization of DNA for fluorescence microscopy utilizes a variety of dyes such as cyanine dyes. These dyes are utilized due to their high affinity and sensitivity for DNA. In order to determine if the DNA molecules are full length after the completion of the experiment, a method is required to determine if the stained molecules are full length by digesting DNA with restriction enzymes. However, stained DNA may inhibit the enzymes, so a method is needed to determine what enzymes one could use for fluorochrome stained DNA. In this method, DNA is stained with a cyanine dye overnight to allow the dye and DNA to equilibrate. Next, stained DNA is digested with a restriction enzyme, loaded into a gel and electrophoresed. The experimental DNA digest bands are compared to an in silico digest to determine the restriction enzyme activity. If there is the same number of bands as expected, then the reaction is complete. More bands than expected indicate partial digestion and less bands indicate incomplete digestion. The advantage of this method is its simplicity and it uses equipment that a scientist would need for a restriction enzyme assay and gel electrophoresis. A limitation of this method is that the enzymes available to most scientists are commercially available enzymes; however, any restriction enzymes could be used.
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Affiliation(s)
| | - Cody Masters
- Department of Chemistry, University of Nebraska - Kearney
| | | | - Joshua Lallman
- Department of Chemistry, University of Nebraska - Kearney
| | - Drew Thompson
- Department of Chemistry, University of Nebraska - Kearney
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Abstract
A high-quality, annotated genome assembly is the foundation for many downstream studies. However, obtaining such an assembly is a complex, reiterative process that requires the assimilation of high-quality data and combines different approaches and data types. While some software packages incorporating multiple steps of genome assembly are commercially available, they may not be flexible enough to be routinely applied to all organisms, particularly to nonmodel species such as pathogenic oomycetes and fungi. If researchers understand and apply the most appropriate, currently available tools for each step, it is possible to customize parameters and optimize results for their organism of study. Based on our experience of de novo assembly and annotation of several oomycete species, this chapter provides a modular workflow from processing of raw reads, to initial assembly generation, through optimization, chromosome-scale scaffolding and annotation, outlining input and output data as well as examples and alternative software used for each step. The accompanying Notes provide background information for each step as well as alternative options. The final result of this workflow could be an annotated, high-quality, validated, chromosome-scale assembly or a draft assembly of sufficient quality to meet specific needs of a project.
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Affiliation(s)
- Kyle Fletcher
- The Genome Center, Genome and Biomedical Sciences Facility, University of California, Davis, CA, USA
| | - Richard Michelmore
- The Genome Center, Genome and Biomedical Sciences Facility, University of California, Davis, CA, USA.
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9
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Jia Z, Liang Y, Ma B, Xu X, Xiong J, Duan L, Wang D. A 5-mC Dot Blot Assay Quantifying the DNA Methylation Level of Chondrocyte Dedifferentiation In Vitro. J Vis Exp 2017:55565. [PMID: 28570531 PMCID: PMC5607994 DOI: 10.3791/55565] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The dedifferentiation of hyaline chondrocytes into fibroblastic chondrocytes often accompanies monolayer expansion of chondrocytes in vitro. The global DNA methylation level of chondrocytes is considered to be a suitable biomarker for the loss of the chondrocyte phenotype. However, results based on different experimental methods can be inconsistent. Therefore, it is important to establish a precise, simple, and rapid method to quantify global DNA methylation levels during chondrocyte dedifferentiation. Current genome-wide methylation analysis techniques largely rely on bisulfite genomic sequencing. Due to DNA degradation during bisulfite conversion, these methods typically require a large sample volume. Other methods used to quantify global DNA methylation levels include high-performance liquid chromatography (HPLC). However, HPLC requires complete digestion of genomic DNA. Additionally, the prohibitively high cost of HPLC instruments limits HPLC's wider application. In this study, genomic DNA (gDNA) was extracted from human chondrocytes cultured with varying number of passages. The gDNA methylation level was detected using a methylation-specific dot blot assay. In this dot blot approach, a gDNA mixture containing the methylated DNA to be detected was spotted directly onto an N+ membrane as a dot inside a previously drawn circular template pattern. Compared with other gel electrophoresis-based blotting approaches and other complex blotting procedures, the dot blot method saves significant time. In addition, dot blots can detect overall DNA methylation level using a commercially available 5-mC antibody. We found that the DNA methylation level differed between the monolayer subcultures, and therefore could play a key role in chondrocyte dedifferentiation. The 5-mC dot blot is a reliable, simple, and rapid method to detect the general DNA methylation level to evaluate chondrocyte phenotype.
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Affiliation(s)
- Zhaofeng Jia
- Guangzhou Medical University; Shenzhen Key Laboratory of Tissue Engineering, Shenzhen Laboratory of Digital Orthopeadic Engineering, Department of Orthopedics, Shenzhen Second People's Hospital (The First Hospital Affiliated to Shenzhen University)
| | - Yujie Liang
- Department of Chemistry, The Chinese University of Hong Kong
| | - Bin Ma
- School of Biomedical Engineering, Shanghai Jiao Tong University; Renji Hospital Clinical Stem Cell Research Center, Shanghai Jiao Tong University School of Medicine
| | - Xiao Xu
- Shenzhen Key Laboratory of Tissue Engineering, Shenzhen Laboratory of Digital Orthopeadic Engineering, Department of Orthopedics, Shenzhen Second People's Hospital (The First Hospital Affiliated to Shenzhen University); Shantou University Medical College
| | - Jianyi Xiong
- Shenzhen Key Laboratory of Tissue Engineering, Shenzhen Laboratory of Digital Orthopeadic Engineering, Department of Orthopedics, Shenzhen Second People's Hospital (The First Hospital Affiliated to Shenzhen University)
| | - Li Duan
- Shenzhen Key Laboratory of Tissue Engineering, Shenzhen Laboratory of Digital Orthopeadic Engineering, Department of Orthopedics, Shenzhen Second People's Hospital (The First Hospital Affiliated to Shenzhen University);
| | - Daping Wang
- Guangzhou Medical University; Shenzhen Key Laboratory of Tissue Engineering, Shenzhen Laboratory of Digital Orthopeadic Engineering, Department of Orthopedics, Shenzhen Second People's Hospital (The First Hospital Affiliated to Shenzhen University);
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Deen J, Vranken C, Leen V, Neely RK, Janssen KPF, Hofkens J. Methyltransferase-Directed Labeling of Biomolecules and its Applications. Angew Chem Int Ed Engl 2017; 56:5182-5200. [PMID: 27943567 PMCID: PMC5502580 DOI: 10.1002/anie.201608625] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2016] [Indexed: 01/01/2023]
Abstract
Methyltransferases (MTases) form a large family of enzymes that methylate a diverse set of targets, ranging from the three major biopolymers to small molecules. Most of these MTases use the cofactor S-adenosyl-l-Methionine (AdoMet) as a methyl source. In recent years, there have been significant efforts toward the development of AdoMet analogues with the aim of transferring moieties other than simple methyl groups. Two major classes of AdoMet analogues currently exist: doubly-activated molecules and aziridine based molecules, each of which employs a different approach to achieve transalkylation rather than transmethylation. In this review, we discuss the various strategies for labelling and functionalizing biomolecules using AdoMet-dependent MTases and AdoMet analogues. We cover the synthetic routes to AdoMet analogues, their stability in biological environments and their application in transalkylation reactions. Finally, some perspectives are presented for the potential use of AdoMet analogues in biology research, (epi)genetics and nanotechnology.
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Affiliation(s)
- Jochem Deen
- Laboratory of Nanoscale BiologySchool of Engineering, EPFL, STI IBI-STI LBEN BM 5134 (Bâtiment BM)Station 17CH-1015LausanneSwitzerland
| | - Charlotte Vranken
- Laboratory of Photochemistry and Spectroscopy, Department of ChemistryKU LeuvenCelestijnenlaan 200FB-3001HeverleeBelgium
| | - Volker Leen
- Laboratory of Photochemistry and Spectroscopy, Department of ChemistryKU LeuvenCelestijnenlaan 200FB-3001HeverleeBelgium
| | - Robert K. Neely
- School of ChemistryUniversity of BirminghamEdgbastonBirminghamB15 2TTUK
| | - Kris P. F. Janssen
- Laboratory of Photochemistry and Spectroscopy, Department of ChemistryKU LeuvenCelestijnenlaan 200FB-3001HeverleeBelgium
| | - Johan Hofkens
- Laboratory of Photochemistry and Spectroscopy, Department of ChemistryKU LeuvenCelestijnenlaan 200FB-3001HeverleeBelgium
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Deen J, Vranken C, Leen V, Neely RK, Janssen KPF, Hofkens J. Die Methyltransferase-gesteuerte Markierung von Biomolekülen und ihre Anwendungen. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201608625] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Jochem Deen
- Laboratory of Nanoscale Biology; School of Engineering, EPFL, STI IBI-STI LBEN BM 5134 (Bâtiment BM); Station 17 CH-1015 Lausanne Schweiz
| | - Charlotte Vranken
- Laboratory of Photochemistry and Spectroscopy, Department of Chemistry; KU Leuven; Celestijnenlaan 200F B-3001 Heverlee Belgien
| | - Volker Leen
- Laboratory of Photochemistry and Spectroscopy, Department of Chemistry; KU Leuven; Celestijnenlaan 200F B-3001 Heverlee Belgien
| | - Robert K. Neely
- School of Chemistry; University of Birmingham; Edgbaston Birmingham B15 2TT Großbritannien
| | - Kris P. F. Janssen
- Laboratory of Photochemistry and Spectroscopy, Department of Chemistry; KU Leuven; Celestijnenlaan 200F B-3001 Heverlee Belgien
| | - Johan Hofkens
- Laboratory of Photochemistry and Spectroscopy, Department of Chemistry; KU Leuven; Celestijnenlaan 200F B-3001 Heverlee Belgien
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Maschmann A, Kounovsky-Shafer KL. Determination of restriction enzyme activity when cutting DNA labeled with the TOTO dye family. NUCLEOSIDES NUCLEOTIDES & NUCLEIC ACIDS 2017; 36:406-417. [PMID: 28362164 DOI: 10.1080/15257770.2017.1300665] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Optical mapping, a single DNA molecule genome analysis platform that can determine methylation profiles, uses fluorescently labeled DNA molecules that are elongated on the surface and digested with a restriction enzyme to produce a barcode of that molecule. Understanding how the cyanine fluorochromes affect enzyme activity can lead to other fluorochromes used in the optical mapping system. The effects of restriction digestion on fluorochrome labeled DNA (Ethidium Bromide, DAPI, H33258, EthD-1, TOTO-1) have been analyzed previously. However, TOTO-1 is a part of a family of cyanine fluorochromes (YOYO-1, TOTO-1, BOBO-1, POPO-1, YOYO-3, TOTO-3, BOBO-3, and POPO-3) and the rest of the fluorochromes have not been examined in terms of their effects on restriction digestion. In order to determine if the other dyes in the TOTO-1 family inhibit restriction enzymes in the same way as TOTO-1, lambda DNA was stained with a dye from the TOTO family and digested. The restriction enzyme activity in regards to each dye, as well as each restriction enzyme, was compared to determine the extent of digestion. YOYO-1, TOTO-1, and POPO-1 fluorochromes inhibited ScaI-HF, PmlI, and EcoRI restriction enzymes. Additionally, the mobility of labeled DNA fragments in an agarose gel changed depending on which dye was intercalated.
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Affiliation(s)
- April Maschmann
- a Department of Chemistry , University of Nebraska-Kearney , Kearney , NE , USA
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13
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Zillner K, Komatsu J, Filarsky K, Kalepu R, Bensimon A, Németh A. Active human nucleolar organizer regions are interspersed with inactive rDNA repeats in normal and tumor cells. Epigenomics 2015; 7:363-78. [PMID: 26077426 DOI: 10.2217/epi.14.93] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
AIM The synthesis of rRNA is a key determinant of normal and malignant cell growth and subject to epigenetic regulation. Yet, the epigenomic features of rDNA arrays clustered in nucleolar organizer regions are largely unknown. We set out to explore for the first time how DNA methylation is distributed on individual rDNA arrays. MATERIALS & METHODS Here we combined immunofluorescence detection of DNA modifications with fluorescence hybridization of single DNA fibers, metaphase immuno-FISH and methylation-sensitive restriction enzyme digestions followed by Southern blot. RESULTS We found clustering of both hypomethylated and hypermethylated repeat units and hypermethylation of noncanonical rDNA in IMR90 fibroblasts and HCT116 colorectal carcinoma cells. Surprisingly, we also found transitions between hypo- and hypermethylated rDNA repeat clusters on single DNA fibers. CONCLUSION Collectively, our analyses revealed co-existence of different epialleles on individual nucleolar organizer regions and showed that epi-combing is a valuable approach to analyze epigenomic patterns of repetitive DNA.
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Affiliation(s)
- Karina Zillner
- Department of Biochemistry III, Biochemistry Center Regensburg, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Jun Komatsu
- Genomic Vision, 80 Rue des Meuniers, 92220 Bagneux, France
| | - Katharina Filarsky
- Department of Biochemistry III, Biochemistry Center Regensburg, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany.,German Cancer Research Center (DKFZ), Heidelberg 69120, Germany
| | - Rajakiran Kalepu
- Department of Biochemistry III, Biochemistry Center Regensburg, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany.,University Hospital Ulm, Ulm 89070, Germany
| | - Aaron Bensimon
- Genomic Vision, 80 Rue des Meuniers, 92220 Bagneux, France
| | - Attila Németh
- Department of Biochemistry III, Biochemistry Center Regensburg, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
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14
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Chapleau RR, Baldwin JC. Optical Whole-Genome Restriction Mapping as a Tool for Rapidly Distinguishing and Identifying Bacterial Contaminants in Clinical Samples. J Clin Diagn Res 2015; 9:DC24-7. [PMID: 26435946 DOI: 10.7860/jcdr/2015/13983.6408] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Accepted: 06/09/2015] [Indexed: 12/11/2022]
Abstract
INTRODUCTION Optical restriction genome mapping is a technology in which a genome is linearized on a surface and digested with specific restriction enzymes, giving an arrangement of the genome with gaps whose order and size are unique for a given organism. Current applications of this technology include assisting with the correct scaffolding and ordering of genomes in conjunction with whole-genome sequencing, observation of genetic drift and evolution using comparative genomics and epidemiological monitoring of the spread of infections. Here, we investigated the suitability of genome mapping for use in clinical labs as a potential diagnostic tool. MATERIALS AND METHODS Using whole genome mapping, we investigated the basic performance of the technology for identifying two bacteria of interest for food-safety (Lactobacilli spp. and Enterohemorrhagic Escherichia coli). We further evaluated the performance for identifying multiple organisms from both simple and complex mixtures. RESULTS We were able to successfully generate optical restriction maps of four Lactobacillus species as well as a strain of Enterohemorrhagic Escherichia coli from within a mixed solution, each distinguished using a common compatible restriction enzyme. Finally, we demonstrated that optical restriction maps were successfully obtained and the correct organism identified within a clinical matrix. CONCLUSION With additional development, whole genome mapping may be a useful clinical tool for rapid invitro diagnostics.
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Affiliation(s)
- Richard R Chapleau
- Applied Technology and Genomics Center, United States Air Force School of Aerospace Medicine , 711th Human Performance Wing, Air Force Research Laboratory, Wright-Patterson AFB OH
| | - James C Baldwin
- Applied Technology and Genomics Center, United States Air Force School of Aerospace Medicine , 711th Human Performance Wing, Air Force Research Laboratory, Wright-Patterson AFB OH
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15
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A fast and scalable kymograph alignment algorithm for nanochannel-based optical DNA mappings. PLoS One 2015; 10:e0121905. [PMID: 25875920 PMCID: PMC4395267 DOI: 10.1371/journal.pone.0121905] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Accepted: 02/05/2015] [Indexed: 11/26/2022] Open
Abstract
Optical mapping by direct visualization of individual DNA molecules, stretched in nanochannels with sequence-specific fluorescent labeling, represents a promising tool for disease diagnostics and genomics. An important challenge for this technique is thermal motion of the DNA as it undergoes imaging; this blurs fluorescent patterns along the DNA and results in information loss. Correcting for this effect (a process referred to as kymograph alignment) is a common preprocessing step in nanochannel-based optical mapping workflows, and we present here a highly efficient algorithm to accomplish this via pattern recognition. We compare our method with the one previous approach, and we find that our method is orders of magnitude faster while producing data of similar quality. We demonstrate proof of principle of our approach on experimental data consisting of melt mapped bacteriophage DNA.
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16
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Howe K, Wood JMD. Using optical mapping data for the improvement of vertebrate genome assemblies. Gigascience 2015; 4:10. [PMID: 25789164 PMCID: PMC4364110 DOI: 10.1186/s13742-015-0052-y] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 03/05/2015] [Indexed: 11/10/2022] Open
Abstract
Optical mapping is a technology that gathers long-range information on genome sequences similar to ordered restriction digest maps. Because it is not subject to cloning, amplification, hybridisation or sequencing bias, it is ideally suited to the improvement of fragmented genome assemblies that can no longer be improved by classical methods. In addition, its low cost and rapid turnaround make it equally useful during the scaffolding process of de novo assembly from high throughput sequencing reads. We describe how optical mapping has been used in practice to produce high quality vertebrate genome assemblies. In particular, we detail the efforts undertaken by the Genome Reference Consortium (GRC), which maintains the reference genomes for human, mouse, zebrafish and chicken, and uses different optical mapping platforms for genome curation.
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Affiliation(s)
- Kerstin Howe
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus Hinxton, Cambridge, UK
| | - Jonathan M D Wood
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus Hinxton, Cambridge, UK
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17
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Deen J, Sempels W, De Dier R, Vermant J, Dedecker P, Hofkens J, Neely RK. Combing of genomic DNA from droplets containing picograms of material. ACS NANO 2015; 9:809-816. [PMID: 25561163 PMCID: PMC4344373 DOI: 10.1021/nn5063497] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Accepted: 01/05/2015] [Indexed: 05/30/2023]
Abstract
Deposition of linear DNA molecules is a critical step in many single-molecule genomic approaches including DNA mapping, fiber-FISH, and several emerging sequencing technologies. In the ideal situation, the DNA that is deposited for these experiments is absolutely linear and uniformly stretched, thereby enabling accurate distance measurements. However, this is rarely the case, and furthermore, current approaches for the capture and linearization of DNA on a surface tend to require complex surface preparation and large amounts of starting material to achieve genomic-scale mapping. This makes them technically demanding and prevents their application in emerging fields of genomics, such as single-cell based analyses. Here we describe a simple and extremely efficient approach to the deposition and linearization of genomic DNA molecules. We employ droplets containing as little as tens of picograms of material and simply drag them, using a pipet tip, over a polymer-coated coverslip. In this report we highlight one particular polymer, Zeonex, which is remarkably efficient at capturing DNA. We characterize the method of DNA capture on the Zeonex surface and find that the use of droplets greatly facilitates the efficient deposition of DNA. This is the result of a circulating flow in the droplet that maintains a high DNA concentration at the interface of the surface/solution. Overall, our approach provides an accessible route to the study of genomic structural variation from samples containing no more than a handful of cells.
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Affiliation(s)
- Jochem Deen
- Department of Chemistry, KU Leuven, Celestijnenlaan 200F, Heverlee 3001, Belgium
| | - Wouter Sempels
- Department of Chemistry, KU Leuven, Celestijnenlaan 200F, Heverlee 3001, Belgium
| | - Raf De Dier
- Department of Chemical Engineering, KU Leuven, Willem de Croylaan 46, Heverlee 3001, Belgium
| | - Jan Vermant
- Department of Chemical Engineering, KU Leuven, Willem de Croylaan 46, Heverlee 3001, Belgium
- Department of Materials, ETH Zürich, Vladimir Prelog Weg 5, CH 8093 Zürich, Switzerland
| | - Peter Dedecker
- Department of Chemistry, KU Leuven, Celestijnenlaan 200F, Heverlee 3001, Belgium
| | - Johan Hofkens
- Department of Chemistry, KU Leuven, Celestijnenlaan 200F, Heverlee 3001, Belgium
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - Robert K. Neely
- Department of Chemistry, KU Leuven, Celestijnenlaan 200F, Heverlee 3001, Belgium
- School of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
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18
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Xavier BB, Sabirova J, Pieter M, Hernalsteens JP, de Greve H, Goossens H, Malhotra-Kumar S. Employing whole genome mapping for optimal de novo assembly of bacterial genomes. BMC Res Notes 2014; 7:484. [PMID: 25077983 PMCID: PMC4118782 DOI: 10.1186/1756-0500-7-484] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Accepted: 07/21/2014] [Indexed: 11/18/2022] Open
Abstract
Background De novo genome assembly can be challenging due to inherent properties of the reads, even when using current state-of-the-art assembly tools based on de Bruijn graphs. Often users are not bio-informaticians and, in a black box approach, utilise assembly parameters such as contig length and N50 to generate whole genome sequences, potentially resulting in mis-assemblies. Findings Utilising several assembly tools based on de Bruijn graphs like Velvet, SPAdes and IDBA, we demonstrate that at the optimal N50, mis-assemblies do occur, even when using the multi-k-mer approaches of SPAdes and IDBA. We demonstrate that whole genome mapping can be used to identify these mis-assemblies and can guide the selection of the best k-mer size which yields the highest N50 without mis-assemblies. Conclusions We demonstrate the utility of whole genome mapping (WGM) as a tool to identify mis-assemblies and to guide k-mer selection and higher quality de novo genome assembly of bacterial genomes.
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Affiliation(s)
| | | | | | | | | | | | - Surbhi Malhotra-Kumar
- Department of Medical Microbiology, Vaccine & Infectious Disease Institute, Universiteit Antwerpen, Antwerp, Belgium.
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Levy-Sakin M, Grunwald A, Kim S, Gassman NR, Gottfried A, Antelman J, Kim Y, Ho S, Samuel R, Michalet X, Lin RR, Dertinger T, Kim AS, Chung S, Colyer RA, Weinhold E, Weiss S, Ebenstein Y. Toward single-molecule optical mapping of the epigenome. ACS NANO 2014; 8:14-26. [PMID: 24328256 PMCID: PMC4022788 DOI: 10.1021/nn4050694] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The past decade has seen an explosive growth in the utilization of single-molecule techniques for the study of complex systems. The ability to resolve phenomena otherwise masked by ensemble averaging has made these approaches especially attractive for the study of biological systems, where stochastic events lead to inherent inhomogeneity at the population level. The complex composition of the genome has made it an ideal system to study at the single-molecule level, and methods aimed at resolving genetic information from long, individual, genomic DNA molecules have been in use for the last 30 years. These methods, and particularly optical-based mapping of DNA, have been instrumental in highlighting genomic variation and contributed significantly to the assembly of many genomes including the human genome. Nanotechnology and nanoscopy have been a strong driving force for advancing genomic mapping approaches, allowing both better manipulation of DNA on the nanoscale and enhanced optical resolving power for analysis of genomic information. During the past few years, these developments have been adopted also for epigenetic studies. The common principle for these studies is the use of advanced optical microscopy for the detection of fluorescently labeled epigenetic marks on long, extended DNA molecules. Here we will discuss recent single-molecule studies for the mapping of chromatin composition and epigenetic DNA modifications, such as DNA methylation.
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Affiliation(s)
- Michal Levy-Sakin
- Raymond and Beverly Sackler Faculty of Exact Sciences, School of Chemistry, Tel Aviv University, Tel Aviv, Israel
| | - Assaf Grunwald
- Raymond and Beverly Sackler Faculty of Exact Sciences, School of Chemistry, Tel Aviv University, Tel Aviv, Israel
| | - Soohong Kim
- Department of Chemistry and Biochemistry, University of California, Los Angeles, USA
| | - Natalie R. Gassman
- Department of Chemistry and Biochemistry, University of California, Los Angeles, USA
| | - Anna Gottfried
- Institute of Organic Chemistry, RWTH Aachen University, Aachen, Germany
| | - Josh Antelman
- Department of Chemistry and Biochemistry, University of California, Los Angeles, USA
| | - Younggyu Kim
- Department of Chemistry and Biochemistry, University of California, Los Angeles, USA
| | - Sam Ho
- Department of Chemistry and Biochemistry, University of California, Los Angeles, USA
| | - Robin Samuel
- Department of Chemistry and Biochemistry, University of California, Los Angeles, USA
| | - Xavier Michalet
- Department of Chemistry and Biochemistry, University of California, Los Angeles, USA
| | - Ron R. Lin
- Department of Chemistry and Biochemistry, University of California, Los Angeles, USA
| | - Thomas Dertinger
- Department of Chemistry and Biochemistry, University of California, Los Angeles, USA
| | - Andrew S. Kim
- Department of Chemistry and Biochemistry, University of California, Los Angeles, USA
| | - Sangyoon Chung
- Department of Chemistry and Biochemistry, University of California, Los Angeles, USA
| | - Ryan A. Colyer
- Department of Chemistry and Biochemistry, University of California, Los Angeles, USA
| | - Elmar Weinhold
- Institute of Organic Chemistry, RWTH Aachen University, Aachen, Germany
| | - Shimon Weiss
- Department of Chemistry and Biochemistry, University of California, Los Angeles, USA
- Corresponding authors: (Y. Ebenstein), (S. Weiss)
| | - Yuval Ebenstein
- Raymond and Beverly Sackler Faculty of Exact Sciences, School of Chemistry, Tel Aviv University, Tel Aviv, Israel
- Corresponding authors: (Y. Ebenstein), (S. Weiss)
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20
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Beyond sequencing: optical mapping of DNA in the age of nanotechnology and nanoscopy. Curr Opin Biotechnol 2013; 24:690-8. [DOI: 10.1016/j.copbio.2013.01.009] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Revised: 01/20/2013] [Accepted: 01/22/2013] [Indexed: 12/25/2022]
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21
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Discovery of structural alterations in solid tumor oligodendroglioma by single molecule analysis. BMC Genomics 2013; 14:505. [PMID: 23885787 PMCID: PMC3727977 DOI: 10.1186/1471-2164-14-505] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Accepted: 07/23/2013] [Indexed: 12/31/2022] Open
Abstract
Background Solid tumors present a panoply of genomic alterations, from single base changes to the gain or loss of entire chromosomes. Although aberrations at the two extremes of this spectrum are readily defined, comprehensive discernment of the complex and disperse mutational spectrum of cancer genomes remains a significant challenge for current genome analysis platforms. In this context, high throughput, single molecule platforms like Optical Mapping offer a unique perspective. Results Using measurements from large ensembles of individual DNA molecules, we have discovered genomic structural alterations in the solid tumor oligodendroglioma. Over a thousand structural variants were identified in each tumor sample, without any prior hypotheses, and often in genomic regions deemed intractable by other technologies. These findings were then validated by comprehensive comparisons to variants reported in external and internal databases, and by selected experimental corroborations. Alterations range in size from under 5 kb to hundreds of kilobases, and comprise insertions, deletions, inversions and compound events. Candidate mutations were scored at sub-genic resolution and unambiguously reveal structural details at aberrant loci. Conclusions The Optical Mapping system provides a rich description of the complex genomes of solid tumors, including sequence level aberrations, structural alterations and copy number variants that power generation of functional hypotheses for oligodendroglioma genetics.
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22
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Dorfman KD, King SB, Olson DW, Thomas JDP, Tree DR. Beyond gel electrophoresis: microfluidic separations, fluorescence burst analysis, and DNA stretching. Chem Rev 2013; 113:2584-667. [PMID: 23140825 PMCID: PMC3595390 DOI: 10.1021/cr3002142] [Citation(s) in RCA: 141] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Kevin D. Dorfman
- Department of Chemical Engineering and Materials Science, University of Minnesota — Twin Cities, 421 Washington Ave. SE, Minneapolis, MN 55455, Phone: 1-612-624-5560. Fax: 1-612-626-7246
| | - Scott B. King
- Department of Chemical Engineering and Materials Science, University of Minnesota — Twin Cities, 421 Washington Ave. SE, Minneapolis, MN 55455, Phone: 1-612-624-5560. Fax: 1-612-626-7246
| | - Daniel W. Olson
- Department of Chemical Engineering and Materials Science, University of Minnesota — Twin Cities, 421 Washington Ave. SE, Minneapolis, MN 55455, Phone: 1-612-624-5560. Fax: 1-612-626-7246
| | - Joel D. P. Thomas
- Department of Chemical Engineering and Materials Science, University of Minnesota — Twin Cities, 421 Washington Ave. SE, Minneapolis, MN 55455, Phone: 1-612-624-5560. Fax: 1-612-626-7246
| | - Douglas R. Tree
- Department of Chemical Engineering and Materials Science, University of Minnesota — Twin Cities, 421 Washington Ave. SE, Minneapolis, MN 55455, Phone: 1-612-624-5560. Fax: 1-612-626-7246
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23
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Zillner K, Németh A. Single-molecule, genome-scale analyses of DNA modifications: exposing the epigenome with next-generation technologies. Epigenomics 2012; 4:403-14. [PMID: 22920180 DOI: 10.2217/epi.12.30] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
DNA modifications represent an integral part of the epigenome and they have a pivotal role in regulation of genome function. Despite the wide variety of analytical techniques that have been developed to detect DNA modifications, their investigation at the single-genome level is only beginning to emerge. In contrast to population-averaged analyses, single-molecule approaches potentially allow the mapping of epigenetic linkage between distantly located genomic regions, the locus-specific analysis of repetitive DNA elements, as well as determination of allele-specific DNA modification patterns. In this article, the properties of current single-molecule analyses of DNA modifications will be discussed and compared. In addition, the possible biomedical and discovery research applications of single-molecule epigenomics will be highlighted.
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Affiliation(s)
- Karina Zillner
- Biochemistry Center Regensburg, University of Regensburg, Universitätsstrasse 31, D-93053, Regensburg, Germany
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24
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Comparative whole-genome mapping to determine Staphylococcus aureus genome size, virulence motifs, and clonality. J Clin Microbiol 2012; 50:3526-33. [PMID: 22915603 DOI: 10.1128/jcm.01168-12] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Despite being a clonal pathogen, Staphylococcus aureus continues to acquire virulence and antibiotic-resistant genes located on mobile genetic elements such as genomic islands, prophages, pathogenicity islands, and the staphylococcal chromosomal cassette mec (SCCmec) by horizontal gene transfer from other staphylococci. The potential virulence of a S. aureus strain is often determined by comparing its pulsed-field gel electrophoresis (PFGE) or multilocus sequence typing profiles to that of known epidemic or virulent clones and by PCR of the toxin genes. Whole-genome mapping (formerly optical mapping), which is a high-resolution ordered restriction mapping of a bacterial genome, is a relatively new genomic tool that allows comparative analysis across entire bacterial genomes to identify regions of genomic similarities and dissimilarities, including small and large insertions and deletions. We explored whether whole-genome maps (WGMs) of methicillin-resistant S. aureus (MRSA) could be used to predict the presence of methicillin resistance, SCCmec type, and Panton-Valentine leukocidin (PVL)-producing genes on an S. aureus genome. We determined the WGMs of 47 diverse clinical isolates of S. aureus, including well-characterized reference MRSA strains, and annotated the signature restriction pattern in SCCmec types, arginine catabolic mobile element (ACME), and PVL-carrying prophage, PhiSa2 or PhiSa2-like regions on the genome. WGMs of these isolates accurately characterized them as MRSA or methicillin-sensitive S. aureus based on the presence or absence of the SCCmec motif, ACME and the unique signature pattern for the prophage insertion that harbored the PVL genes. Susceptibility to methicillin resistance and the presence of mecA, SCCmec types, and PVL genes were confirmed by PCR. A WGM clustering approach was further able to discriminate isolates within the same PFGE clonal group. These results showed that WGMs could be used not only to genotype S. aureus but also to identify genetic motifs in MRSA that may predict virulence.
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25
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Doležel J, Vrána J, Safář J, Bartoš J, Kubaláková M, Simková H. Chromosomes in the flow to simplify genome analysis. Funct Integr Genomics 2012; 12:397-416. [PMID: 22895700 PMCID: PMC3431466 DOI: 10.1007/s10142-012-0293-0] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2012] [Accepted: 07/30/2012] [Indexed: 11/25/2022]
Abstract
Nuclear genomes of human, animals, and plants are organized into subunits called chromosomes. When isolated into aqueous suspension, mitotic chromosomes can be classified using flow cytometry according to light scatter and fluorescence parameters. Chromosomes of interest can be purified by flow sorting if they can be resolved from other chromosomes in a karyotype. The analysis and sorting are carried out at rates of 10(2)-10(4) chromosomes per second, and for complex genomes such as wheat the flow sorting technology has been ground-breaking in reducing genome complexity for genome sequencing. The high sample rate provides an attractive approach for karyotype analysis (flow karyotyping) and the purification of chromosomes in large numbers. In characterizing the chromosome complement of an organism, the high number that can be studied using flow cytometry allows for a statistically accurate analysis. Chromosome sorting plays a particularly important role in the analysis of nuclear genome structure and the analysis of particular and aberrant chromosomes. Other attractive but not well-explored features include the analysis of chromosomal proteins, chromosome ultrastructure, and high-resolution mapping using FISH. Recent results demonstrate that chromosome flow sorting can be coupled seamlessly with DNA array and next-generation sequencing technologies for high-throughput analyses. The main advantages are targeting the analysis to a genome region of interest and a significant reduction in sample complexity. As flow sorters can also sort single copies of chromosomes, shotgun sequencing DNA amplified from them enables the production of haplotype-resolved genome sequences. This review explains the principles of flow cytometric chromosome analysis and sorting (flow cytogenetics), discusses the major uses of this technology in genome analysis, and outlines future directions.
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Affiliation(s)
- Jaroslav Doležel
- Centre of the Region Haná for Biotechnological and Agricultural Research, Institute of Experimental Botany, Sokolovská 6, Olomouc, Czech Republic.
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26
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Kim Y, Kim KS, Kounovsky KL, Chang R, Jung GY, de Pablo JJ, Jo K, Schwartz DC. Nanochannel confinement: DNA stretch approaching full contour length. LAB ON A CHIP 2011; 11:1721-9. [PMID: 21431167 PMCID: PMC3222331 DOI: 10.1039/c0lc00680g] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Fully stretched DNA molecules are becoming a fundamental component of new systems for comprehensive genome analysis. Among a number of approaches for elongating DNA molecules, nanofluidic molecular confinement has received enormous attentions from physical and biological communities for the last several years. Here we demonstrate a well-optimized condition that a DNA molecule can stretch almost to its full contour length: the average stretch is 19.1 µm ± 1.1 µm for YOYO-1 stained λ DNA (21.8 µm contour length) in 250 nm × 400 nm channel, which is the longest stretch value ever reported in any nanochannels or nanoslits. In addition, based on Odijk's polymer physics theory, we interpret our experimental findings as a function of channel dimensions and ionic strengths. Furthermore, we develop a Monte Carlo simulation approach using a primitive model for the rigorous understanding of DNA confinement effects. Collectively, we present a more complete understanding of nanochannel confined DNA stretching via the comparisons to computer simulation results and Odijk's polymer physics theory.
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Affiliation(s)
- Yoori Kim
- Department of Chemistry and Interdisciplinary Program of Integrated Biotechnology, Sogang University, Seoul, 121-742, Republic of Korea, Tel: +82 2 705 8881
| | - Ki Seok Kim
- Department of Material Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju, 500-712, Republic of Korea
| | - Kristy L. Kounovsky
- Laboratory for Molecular and Computational Genomics, Department of Chemistry, Laboratory of Genetics, University of Wisconsin-Madison, Madison, Wisconsin, 53706 Tel: +1 608 265-0546
| | - Rakwoo Chang
- Department of Chemistry, Kwangwoon University, Seoul 139-701, Republic of Korea
| | - Gun Young Jung
- Department of Material Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju, 500-712, Republic of Korea
| | - Juan J. de Pablo
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, 1415 Engineering Drive, Madison, WI 53706
| | - Kyubong Jo
- Department of Chemistry and Interdisciplinary Program of Integrated Biotechnology, Sogang University, Seoul, 121-742, Republic of Korea, Tel: +82 2 705 8881
| | - David C. Schwartz
- Laboratory for Molecular and Computational Genomics, Department of Chemistry, Laboratory of Genetics, University of Wisconsin-Madison, Madison, Wisconsin, 53706 Tel: +1 608 265-0546
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27
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Abstract
Single-molecule sequencing enables DNA or RNA to be sequenced directly from biological samples, making it well-suited for diagnostic and clinical applications. Here we review the properties and applications of this rapidly evolving and promising technology.
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Affiliation(s)
- John F Thompson
- Helicos BioSciences Corporation, Building 200LL, One Kendall Square, Cambridge, MA 02139, USA.
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28
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Neely RK, Deen J, Hofkens J. Optical mapping of DNA: Single-molecule-based methods for mapping genomes. Biopolymers 2011; 95:298-311. [DOI: 10.1002/bip.21579] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2010] [Revised: 12/15/2010] [Accepted: 12/15/2010] [Indexed: 11/09/2022]
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29
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Teague B, Waterman MS, Goldstein S, Potamousis K, Zhou S, Reslewic S, Sarkar D, Valouev A, Churas C, Kidd JM, Kohn S, Runnheim R, Lamers C, Forrest D, Newton MA, Eichler EE, Kent-First M, Surti U, Livny M, Schwartz DC. High-resolution human genome structure by single-molecule analysis. Proc Natl Acad Sci U S A 2010; 107:10848-53. [PMID: 20534489 PMCID: PMC2890719 DOI: 10.1073/pnas.0914638107] [Citation(s) in RCA: 144] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Variation in genome structure is an important source of human genetic polymorphism: It affects a large proportion of the genome and has a variety of phenotypic consequences relevant to health and disease. In spite of this, human genome structure variation is incompletely characterized due to a lack of approaches for discovering a broad range of structural variants in a global, comprehensive fashion. We addressed this gap with Optical Mapping, a high-throughput, high-resolution single-molecule system for studying genome structure. We used Optical Mapping to create genome-wide restriction maps of a complete hydatidiform mole and three lymphoblast-derived cell lines, and we validated the approach by demonstrating a strong concordance with existing methods. We also describe thousands of new variants with sizes ranging from kb to Mb.
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Affiliation(s)
- Brian Teague
- The Laboratory for Molecular and Computational Genomics, Department of Chemistry, Laboratory of Genetics and Biotechnology Center, University of Wisconsin, 425 Henry Mall, Madison, WI 53706-1580
| | - Michael S. Waterman
- Department of Biological Sciences, University of Southern California, 1050 Childs Way, Los Angeles, CA 90089-2910
| | - Steven Goldstein
- The Laboratory for Molecular and Computational Genomics, Department of Chemistry, Laboratory of Genetics and Biotechnology Center, University of Wisconsin, 425 Henry Mall, Madison, WI 53706-1580
| | - Konstantinos Potamousis
- The Laboratory for Molecular and Computational Genomics, Department of Chemistry, Laboratory of Genetics and Biotechnology Center, University of Wisconsin, 425 Henry Mall, Madison, WI 53706-1580
| | - Shiguo Zhou
- The Laboratory for Molecular and Computational Genomics, Department of Chemistry, Laboratory of Genetics and Biotechnology Center, University of Wisconsin, 425 Henry Mall, Madison, WI 53706-1580
| | - Susan Reslewic
- The Laboratory for Molecular and Computational Genomics, Department of Chemistry, Laboratory of Genetics and Biotechnology Center, University of Wisconsin, 425 Henry Mall, Madison, WI 53706-1580
| | - Deepayan Sarkar
- Department of Statistics, University of Wisconsin, 1300 University Avenue, Madison, WI 53706-1510
| | - Anton Valouev
- Department of Biological Sciences, University of Southern California, 1050 Childs Way, Los Angeles, CA 90089-2910
| | - Christopher Churas
- The Laboratory for Molecular and Computational Genomics, Department of Chemistry, Laboratory of Genetics and Biotechnology Center, University of Wisconsin, 425 Henry Mall, Madison, WI 53706-1580
| | - Jeffrey M. Kidd
- Department of Genome Sciences, University of Washington, 1705 NE Pacific Street, Seattle, WA 98195-5065
| | - Scott Kohn
- The Laboratory for Molecular and Computational Genomics, Department of Chemistry, Laboratory of Genetics and Biotechnology Center, University of Wisconsin, 425 Henry Mall, Madison, WI 53706-1580
| | - Rodney Runnheim
- The Laboratory for Molecular and Computational Genomics, Department of Chemistry, Laboratory of Genetics and Biotechnology Center, University of Wisconsin, 425 Henry Mall, Madison, WI 53706-1580
| | - Casey Lamers
- The Laboratory for Molecular and Computational Genomics, Department of Chemistry, Laboratory of Genetics and Biotechnology Center, University of Wisconsin, 425 Henry Mall, Madison, WI 53706-1580
| | - Dan Forrest
- The Laboratory for Molecular and Computational Genomics, Department of Chemistry, Laboratory of Genetics and Biotechnology Center, University of Wisconsin, 425 Henry Mall, Madison, WI 53706-1580
| | - Michael A. Newton
- Department of Statistics, University of Wisconsin, 1300 University Avenue, Madison, WI 53706-1510
- Department of Biostatistics and Medical Informatics, University of Wisconsin, 1300 University Avenue, Madison, WI 53706-1510
| | - Evan E. Eichler
- Department of Genome Sciences, University of Washington, 1705 NE Pacific Street, Seattle, WA 98195-5065
| | - Marijo Kent-First
- Department of Animal Science, Department of Biological Sciences, Mississippi State University, 130 Harned Hall, Lee Boulevard, Mississippi State, MS 39762-9698
| | - Urvashi Surti
- Department of Pathology, University of Pittsburgh, 200 Lothrop Street, Pittsburgh, PA 15213-2536; and
| | - Miron Livny
- Department of Computer Sciences, University of Wisconsin, 1210 West Dayton Street, Madison, WI 53706-1685
| | - David C. Schwartz
- The Laboratory for Molecular and Computational Genomics, Department of Chemistry, Laboratory of Genetics and Biotechnology Center, University of Wisconsin, 425 Henry Mall, Madison, WI 53706-1580
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30
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Jo K, Chen YL, de Pablo JJ, Schwartz DC. Elongation and migration of single DNA molecules in microchannels using oscillatory shear flows. LAB ON A CHIP 2009; 9:2348-55. [PMID: 19636466 PMCID: PMC2768593 DOI: 10.1039/b902292a] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Much of modern biology relies on the strategic manipulation of molecules for creating ordered arrays prior to high throughput molecular analysis. Normally, DNA arrays involve deposition on surfaces, or confinement in nanochannels; however, we show that microfluidic devices can present stretched molecules within a controlled flow in ways complementing surface modalities, or extreme confinement conditions. Here we utilize pressure-driven oscillatory shear flows generated in microchannels as a new way of stretching DNA molecules for imaging "arrays" of individual DNA molecules. Fluid shear effects both stretch DNA molecules and cause them to migrate away from the walls becoming focused in the centerline of a channel. We show experimental findings confirming simulations using Brownian dynamics accounting for hydrodynamic interactions between molecules and channel-flow boundary conditions. Our findings characterize DNA elongation and migration phenomena as a function of molecular size, shear rate, oscillatory frequency with comparisons to computer simulation studies.
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Affiliation(s)
- Kyubong Jo
- Department of Chemistry and Interdisciplinary Program of Integrated Biotechnology, Sogang University, Seoul, 121-742, Republic of Korea, Tel: +82 2 705-8881; Tel: +82 2 715-7893
| | | | - Juan J. de Pablo
- Department of Chemical and Biological Engineering, University of Wisconsin, 1415 Engineering Drive, Madison, WI 53706,USA
| | - David C. Schwartz
- Laboratory for Molecular and Computational Genomics, Department of Chemistry, Laboratory of Genetics, University of Wisconsin-Madison, UW-Biotechnology Centre, 425 Henry Mall, Madison, WI 53706, USA, Fax: +1 608 265-6743; Tel: +1 608 265-0546
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31
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Sidorova JM, Li N, Schwartz DC, Folch A, Monnat RJ. Microfluidic-assisted analysis of replicating DNA molecules. Nat Protoc 2009; 4:849-61. [PMID: 19444242 DOI: 10.1038/nprot.2009.54] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Single molecule-based protocols have been gaining popularity as a way to visualize DNA replication at the global genomic- and locus-specific levels. These protocols take advantage of the ability of many organisms to incorporate nucleoside analogs during DNA replication, together with a method to display stretched DNA on glass for immunostaining and microscopy. We describe here a microfluidic platform that can be used to stretch and to capture labeled DNA molecules for replication analyses. This platform consists of parallel arrays of three-sided, 3- or 4-microm high, variable-width capillary channels fabricated from polydimethylsiloxane by conventional soft lithography, and of silane-modified glass coverslips to reversibly seal the open side of the channels. Capillary tension in these microchannels facilitates DNA loading, stretching and glass coverslip deposition from microliter-scale DNA samples. The simplicity and extensibility of this platform should facilitate DNA replication analyses using small samples from a variety of biological and clinical sources.
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Affiliation(s)
- Julia M Sidorova
- Department of Pathology, University of Washington, Seattle, Washington, USA.
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