1
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Shan L, Li P, Yu H, Chen LL. Emerging roles of nuclear bodies in genome spatial organization. Trends Cell Biol 2024; 34:595-605. [PMID: 37993310 DOI: 10.1016/j.tcb.2023.10.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 10/09/2023] [Accepted: 10/26/2023] [Indexed: 11/24/2023]
Abstract
Nuclear bodies (NBs) are biomolecular condensates that participate in various cellular processes and respond to cellular stimuli in the nucleus. The assembly and function of these protein- and RNA-rich bodies, such as nucleoli, nuclear speckles, and promyelocytic leukemia (PML) NBs, contribute to the spatial organization of the nucleus, regulating chromatin activities locally and globally. Recent technological advancements, including spatial multiomics approaches, have revealed novel roles of nucleoli in modulating ribosomal DNA (rDNA) and adjacent non-rDNA chromatin activity, nuclear speckles in scaffolding active genome architecture, and PML NBs in maintaining genome stability during stress conditions. In this review, we summarize emerging functions of these important NBs in the spatial organization of the genome, aided by recently developed spatial multiomics approaches toward this direction.
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Affiliation(s)
- Lin Shan
- Key Laboratory of RNA Science and Engineering, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Pan Li
- Key Laboratory of RNA Science and Engineering, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China; Department of Cardiology, Changhai Hospital, Shanghai 200433, China
| | - Hongtao Yu
- School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China; Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China; New Cornerstone Science Laboratory, Shenzhen, China.
| | - Ling-Ling Chen
- Key Laboratory of RNA Science and Engineering, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China; Key Laboratory of Systems Health Science of Zhejiang Province, School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, China; New Cornerstone Science Laboratory, Shenzhen, China.
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2
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Lizana L, Schwartz YB. The scales, mechanisms, and dynamics of the genome architecture. SCIENCE ADVANCES 2024; 10:eadm8167. [PMID: 38598632 PMCID: PMC11006219 DOI: 10.1126/sciadv.adm8167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Accepted: 03/06/2024] [Indexed: 04/12/2024]
Abstract
Even when split into several chromosomes, DNA molecules that make up our genome are too long to fit into the cell nuclei unless massively folded. Such folding must accommodate the need for timely access to selected parts of the genome by transcription factors, RNA polymerases, and DNA replication machinery. Here, we review our current understanding of the genome folding inside the interphase nuclei. We consider the resulting genome architecture at three scales with a particular focus on the intermediate (meso) scale and summarize the insights gained from recent experimental observations and diverse computational models.
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Affiliation(s)
- Ludvig Lizana
- Integrated Science Lab, Department of Physics, Umeå University, Umeå, Sweden
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3
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Lavaud M, Tesfaye R, Lassous L, Brounais B, Baud'huin M, Verrecchia F, Lamoureux F, Georges S, Ory B. Super-enhancers: drivers of cells' identities and cells' debacles. Epigenomics 2024; 16:681-700. [PMID: 38587919 PMCID: PMC11160454 DOI: 10.2217/epi-2023-0409] [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: 11/21/2023] [Accepted: 03/18/2024] [Indexed: 04/10/2024] Open
Abstract
Precise spatiotemporal regulations of gene expression are essential for determining cells' fates and functions. Enhancers are cis-acting DNA elements that act as periodic transcriptional thrusters and their activities are cell type specific. Clusters of enhancers, called super-enhancers, are more densely occupied by transcriptional activators than enhancers, driving stronger expression of their target genes, which have prominent roles in establishing and maintaining cellular identities. Here we review the current knowledge on the composition and structure of super-enhancers to understand how they robustly stimulate the expression of cellular identity genes. We also review their involvement in the development of various cell types and both noncancerous and cancerous disorders, implying the therapeutic interest of targeting them to fight against various diseases.
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Affiliation(s)
- Mélanie Lavaud
- CRCI2NA, INSERM UMR 1307, CNRS UMR 6075, Nantes University & Angers University, Medical School, Nantes, 44035, France
| | - Robel Tesfaye
- CRCI2NA, INSERM UMR 1307, CNRS UMR 6075, Nantes University & Angers University, Medical School, Nantes, 44035, France
- Cancéropôle Grand-Ouest, Réseau Épigénétique, Medical School, Nantes, 44035, France
- EpiSAVMEN, Epigenetic consortium Pays de la Loire, France
| | - Léa Lassous
- CRCI2NA, INSERM UMR 1307, CNRS UMR 6075, Nantes University & Angers University, Medical School, Nantes, 44035, France
| | - Bénédicte Brounais
- CRCI2NA, INSERM UMR 1307, CNRS UMR 6075, Nantes University & Angers University, Medical School, Nantes, 44035, France
| | - Marc Baud'huin
- CRCI2NA, INSERM UMR 1307, CNRS UMR 6075, Nantes University & Angers University, Medical School, Nantes, 44035, France
| | - Franck Verrecchia
- CRCI2NA, INSERM UMR 1307, CNRS UMR 6075, Nantes University & Angers University, Medical School, Nantes, 44035, France
| | - François Lamoureux
- CRCI2NA, INSERM UMR 1307, CNRS UMR 6075, Nantes University & Angers University, Medical School, Nantes, 44035, France
| | - Steven Georges
- CRCI2NA, INSERM UMR 1307, CNRS UMR 6075, Nantes University & Angers University, Medical School, Nantes, 44035, France
| | - Benjamin Ory
- CRCI2NA, INSERM UMR 1307, CNRS UMR 6075, Nantes University & Angers University, Medical School, Nantes, 44035, France
- Cancéropôle Grand-Ouest, Réseau Épigénétique, Medical School, Nantes, 44035, France
- EpiSAVMEN, Epigenetic consortium Pays de la Loire, France
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4
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Han MH, Park J, Park M. Advances in the multimodal analysis of the 3D chromatin structure and gene regulation. Exp Mol Med 2024; 56:763-771. [PMID: 38658704 PMCID: PMC11059362 DOI: 10.1038/s12276-024-01246-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 04/03/2024] [Accepted: 04/08/2024] [Indexed: 04/26/2024] Open
Abstract
Recent studies have demonstrated that the three-dimensional conformation of the chromatin plays a crucial role in gene regulation, with aberrations potentially leading to various diseases. Advanced methodologies have revealed a link between the chromatin conformation and biological function. This review divides these methodologies into sequencing-based and imaging-based methodologies, tracing their development over time. We particularly highlight innovative techniques that facilitate the simultaneous mapping of RNAs, histone modifications, and proteins within the context of the 3D architecture of chromatin. This multimodal integration substantially improves our ability to establish a robust connection between the spatial arrangement of molecular components in the nucleus and their functional roles. Achieving a comprehensive understanding of gene regulation requires capturing diverse data modalities within individual cells, enabling the direct inference of functional relationships between these components. In this context, imaging-based technologies have emerged as an especially promising approach for gathering spatial information across multiple components in the same cell.
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Affiliation(s)
- Man-Hyuk Han
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Jihyun Park
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Minhee Park
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea.
- Graduate School of Engineering Biology, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea.
- KAIST Institute for BioCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea.
- KAIST Stem Cell Center, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea.
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5
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Friedman MJ, Wagner T, Lee H, Rosenfeld MG, Oh S. Enhancer-promoter specificity in gene transcription: molecular mechanisms and disease associations. Exp Mol Med 2024; 56:772-787. [PMID: 38658702 PMCID: PMC11058250 DOI: 10.1038/s12276-024-01233-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2023] [Revised: 02/28/2024] [Accepted: 03/05/2024] [Indexed: 04/26/2024] Open
Abstract
Although often located at a distance from their target gene promoters, enhancers are the primary genomic determinants of temporal and spatial transcriptional specificity in metazoans. Since the discovery of the first enhancer element in simian virus 40, there has been substantial interest in unraveling the mechanism(s) by which enhancers communicate with their partner promoters to ensure proper gene expression. These research efforts have benefited considerably from the application of increasingly sophisticated sequencing- and imaging-based approaches in conjunction with innovative (epi)genome-editing technologies; however, despite various proposed models, the principles of enhancer-promoter interaction have still not been fully elucidated. In this review, we provide an overview of recent progress in the eukaryotic gene transcription field pertaining to enhancer-promoter specificity. A better understanding of the mechanistic basis of lineage- and context-dependent enhancer-promoter engagement, along with the continued identification of functional enhancers, will provide key insights into the spatiotemporal control of gene expression that can reveal therapeutic opportunities for a range of enhancer-related diseases.
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Affiliation(s)
- Meyer J Friedman
- Department and School of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Tobias Wagner
- Department and School of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Haram Lee
- College of Pharmacy Korea University, 2511 Sejong-ro, Sejong, 30019, Republic of Korea
| | - Michael G Rosenfeld
- Department and School of Medicine, University of California, San Diego, La Jolla, CA, USA.
| | - Soohwan Oh
- College of Pharmacy Korea University, 2511 Sejong-ro, Sejong, 30019, Republic of Korea.
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6
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Belan S, Parfenyev V. Footprints of loop extrusion in statistics of intra-chromosomal distances: An analytically solvable model. J Chem Phys 2024; 160:124901. [PMID: 38516975 DOI: 10.1063/5.0199573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Accepted: 03/06/2024] [Indexed: 03/23/2024] Open
Abstract
Active loop extrusion-the process of formation of dynamically growing chromatin loops due to the motor activity of DNA-binding protein complexes-is a firmly established mechanism responsible for chromatin spatial organization at different stages of a cell cycle in eukaryotes and bacteria. The theoretical insight into the effect of loop extrusion on the experimentally measured statistics of chromatin conformation can be gained with an appropriately chosen polymer model. Here, we consider the simplest analytically solvable model of an interphase chromosome, which is treated as an ideal chain with disorder of sufficiently sparse random loops whose conformations are sampled from the equilibrium ensemble. This framework allows us to arrive at the closed-form analytical expression for the mean-squared distance between pairs of genomic loci, which is valid beyond the one-loop approximation in diagrammatic representation. In addition, we analyze the loop-induced deviation of chain conformations from the Gaussian statistics by calculating kurtosis of probability density of the pairwise separation vector. The presented results suggest the possible ways of estimating the characteristics of the loop extrusion process based on the experimental data on the scale-dependent statistics of intra-chromosomal pair-wise distances.
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Affiliation(s)
- Sergey Belan
- Landau Institute for Theoretical Physics, Russian Academy of Sciences, 1-A Akademika Semenova Av., 142432 Chernogolovka, Russia
- National Research University Higher School of Economics, Faculty of Physics, Myasnitskaya 20, 101000 Moscow, Russia
| | - Vladimir Parfenyev
- Landau Institute for Theoretical Physics, Russian Academy of Sciences, 1-A Akademika Semenova Av., 142432 Chernogolovka, Russia
- National Research University Higher School of Economics, Faculty of Physics, Myasnitskaya 20, 101000 Moscow, Russia
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7
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Weinzapfel EN, Fedder-Semmes KN, Sun ZW, Keogh MC. Beyond the tail: the consequence of context in histone post-translational modification and chromatin research. Biochem J 2024; 481:219-244. [PMID: 38353483 PMCID: PMC10903488 DOI: 10.1042/bcj20230342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2023] [Revised: 01/29/2024] [Accepted: 01/31/2024] [Indexed: 02/16/2024]
Abstract
The role of histone post-translational modifications (PTMs) in chromatin structure and genome function has been the subject of intense debate for more than 60 years. Though complex, the discourse can be summarized in two distinct - and deceptively simple - questions: What is the function of histone PTMs? And how should they be studied? Decades of research show these queries are intricately linked and far from straightforward. Here we provide a historical perspective, highlighting how the arrival of new technologies shaped discovery and insight. Despite their limitations, the tools available at each period had a profound impact on chromatin research, and provided essential clues that advanced our understanding of histone PTM function. Finally, we discuss recent advances in the application of defined nucleosome substrates, the study of multivalent chromatin interactions, and new technologies driving the next era of histone PTM research.
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8
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Dutta S, Ghosh A, Spakowitz AJ. Effect of local active fluctuations on structure and dynamics of flexible biopolymers. SOFT MATTER 2024; 20:1694-1701. [PMID: 38226903 DOI: 10.1039/d3sm01491f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2024]
Abstract
Active fluctuations play a significant role in the structure and dynamics of biopolymers (e.g. chromatin and cytoskeletal proteins) that are instrumental in the functioning of living cells. For a large range of experimentally accessible length and time scales, these polymers can be represented as flexible chains that are subjected to spatially and temporally varying fluctuating forces. In this work, we introduce a mathematical framework that correlates the spatial and temporal patterns of the fluctuations to different observables that describe the dynamics and conformations of the polymer. We demonstrate the power of this approach by analyzing the case of a point fluctuation on the polymer with an exponential decay of correlation in time with a finite time constant. Specifically, we identify the length and time scale over which the behavior of the polymer exhibits a significant departure from the behavior of a Rouse chain and the range of impact of the fluctuation along the chain. Furthermore, we show that the conformation of the polymer retains the memory of the active fluctuation from earlier times. Altogether, this work sets the basis for understanding and interpreting the role of spatio-temporal patterns of fluctuations in the dynamics, conformation, and functionality of biopolymers in living cells.
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Affiliation(s)
- Sayantan Dutta
- Department of Chemical Engineering, Stanford University, Stanford, California 94305, USA
| | - Ashesh Ghosh
- Department of Chemical Engineering, Stanford University, Stanford, California 94305, USA
| | - Andrew J Spakowitz
- Department of Chemical Engineering, Stanford University, Stanford, California 94305, USA
- Department of Material Science and Engineering, Stanford University, Stanford, California 94305, USA
- Biophysics Program, Stanford University, Stanford, California 94305, USA.
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9
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Devos X, Fiche JB, Bardou M, Messina O, Houbron C, Gurgo J, Schaeffer M, Götz M, Walter T, Mueller F, Nollmann M. pyHiM: a new open-source, multi-platform software package for spatial genomics based on multiplexed DNA-FISH imaging. Genome Biol 2024; 25:47. [PMID: 38351149 PMCID: PMC10863255 DOI: 10.1186/s13059-024-03178-x] [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: 08/07/2023] [Accepted: 01/29/2024] [Indexed: 02/16/2024] Open
Abstract
Genome-wide ensemble sequencing methods improved our understanding of chromatin organization in eukaryotes but lack the ability to capture single-cell heterogeneity and spatial organization. To overcome these limitations, new imaging-based methods have emerged, giving rise to the field of spatial genomics. Here, we present pyHiM, a user-friendly python toolbox specifically designed for the analysis of multiplexed DNA-FISH data and the reconstruction of chromatin traces in individual cells. pyHiM employs a modular architecture, allowing independent execution of analysis steps and customization according to sample specificity and computing resources. pyHiM aims to facilitate the democratization and standardization of spatial genomics analysis.
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Affiliation(s)
- Xavier Devos
- Centre de Biologie Structurale, Univ Montpellier, CNRS UMR 5048, INSERM U1054, 34090, Montpellier, France
| | - Jean-Bernard Fiche
- Centre de Biologie Structurale, Univ Montpellier, CNRS UMR 5048, INSERM U1054, 34090, Montpellier, France
| | - Marion Bardou
- Centre de Biologie Structurale, Univ Montpellier, CNRS UMR 5048, INSERM U1054, 34090, Montpellier, France
| | - Olivier Messina
- Centre de Biologie Structurale, Univ Montpellier, CNRS UMR 5048, INSERM U1054, 34090, Montpellier, France
| | - Christophe Houbron
- Centre de Biologie Structurale, Univ Montpellier, CNRS UMR 5048, INSERM U1054, 34090, Montpellier, France
| | - Julian Gurgo
- Centre de Biologie Structurale, Univ Montpellier, CNRS UMR 5048, INSERM U1054, 34090, Montpellier, France
| | - Marie Schaeffer
- Centre de Biologie Structurale, Univ Montpellier, CNRS UMR 5048, INSERM U1054, 34090, Montpellier, France
| | - Markus Götz
- Centre de Biologie Structurale, Univ Montpellier, CNRS UMR 5048, INSERM U1054, 34090, Montpellier, France
| | - Thomas Walter
- Centre for Computational Biology (CBIO), Mines Paris, PSL University, 75006, Paris, France
- Institut Curie, 75248, Paris, Cedex, France
- INSERM, U900, 75248, Paris, Cedex, France
| | - Florian Mueller
- Imaging and Modeling Unit, Institut Pasteur, Université Paris Cité, Paris, France
| | - Marcelo Nollmann
- Centre de Biologie Structurale, Univ Montpellier, CNRS UMR 5048, INSERM U1054, 34090, Montpellier, France.
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10
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Fabian-Morales E, Rodríguez A, Gudiño A, Herrera LA, Frias S. Profiling Chromosome Topological Features by Super-Resolution 3D Structured Illumination Microscopy. Methods Mol Biol 2024; 2825:213-237. [PMID: 38913312 DOI: 10.1007/978-1-0716-3946-7_12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/25/2024]
Abstract
Three-dimensional structured illumination microscopy (3D-SIM) and fluorescence in situ hybridization on three-dimensional preserved cells (3D-FISH) have proven to be robust and efficient methodologies for analyzing nuclear architecture and profiling the genome's topological features. These methods have allowed the simultaneous visualization and evaluation of several target structures at super-resolution. In this chapter, we focus on the application of 3D-SIM for the visualization of 3D-FISH preparations of chromosomes in interphase, known as Chromosome Territories (CTs). We provide a workflow and detailed guidelines for sample preparation, image acquisition, and image analysis to obtain quantitative measurements for profiling chromosome topological features. In parallel, we address a practical example of these protocols in the profiling of CTs 9 and 22 involved in the translocation t(9;22) in Chronic Myeloid Leukemia (CML). The profiling of chromosome topological features described in this chapter allowed us to characterize a large-scale topological disruption of CTs 9 and 22 that correlates directly with patients' response to treatment and as a possible potential change in the inheritance systems. These findings open new insights into how the genome structure is associated with the response to cancer treatments, highlighting the importance of microscopy in analyzing the topological features of the genome.
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MESH Headings
- Humans
- In Situ Hybridization, Fluorescence/methods
- Imaging, Three-Dimensional/methods
- Translocation, Genetic
- Chromosomes/genetics
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/genetics
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/pathology
- Interphase/genetics
- Chromosomes, Human/genetics
- Image Processing, Computer-Assisted/methods
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Affiliation(s)
- Eunice Fabian-Morales
- Unidad de Aplicaciones Avanzadas en Microscopía (ADMiRA), Instituto Nacional de Cancerología (INCan), Red de Apoyo a la Investigación (RAI), Universidad Nacional Autónoma de México (UNAM), Mexico City, Mexico
- Unidad de Investigación Biomédica en Cáncer, Instituto Nacional de Cancerología (INCan), Mexico City, Mexico
- Departamento de Medicina Genómica y Toxicología Ambiental, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, Mexico City, Mexico
| | - Alfredo Rodríguez
- Departamento de Medicina Genómica y Toxicología Ambiental, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, Mexico City, Mexico
- Instituto Nacional de Pediatría (INP), Mexico City, Mexico
| | - Adriana Gudiño
- Unidad de Aplicaciones Avanzadas en Microscopía (ADMiRA), Instituto Nacional de Cancerología (INCan), Red de Apoyo a la Investigación (RAI), Universidad Nacional Autónoma de México (UNAM), Mexico City, Mexico
- Unidad de Investigación Biomédica en Cáncer, Instituto Nacional de Cancerología (INCan), Mexico City, Mexico
| | - Luis A Herrera
- Unidad de Investigación Biomédica en Cáncer, Instituto Nacional de Cancerología (INCan), Mexico City, Mexico.
- Departamento de Medicina Genómica y Toxicología Ambiental, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, Mexico City, Mexico.
- Escuela de Medicina y Ciencias de la Salud, Instituto Tecnológico y de Estudios Superiores de Monterrey, Mexico City, Mexico.
| | - Sara Frias
- Departamento de Medicina Genómica y Toxicología Ambiental, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, Mexico City, Mexico.
- Laboratorio de Citogenética, Instituto Nacional de Pediatría (INP), Mexico City, Mexico.
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11
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Cai L, Wang GG. Through the lens of phase separation: intrinsically unstructured protein and chromatin looping. Nucleus 2023; 14:2179766. [PMID: 36821650 PMCID: PMC9980480 DOI: 10.1080/19491034.2023.2179766] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023] Open
Abstract
The establishment, maintenance and dynamic regulation of three-dimensional (3D) chromatin structures provide an important means for partitioning of genome into functionally distinctive domains, which helps to define specialized gene expression programs associated with developmental stages and cell types. Increasing evidence supports critical roles for intrinsically disordered regions (IDRs) harbored within transcription factors (TFs) and chromatin-modulatory proteins in inducing phase separation, a phenomenon of forming membrane-less condensates through partitioning of biomolecules. Such a process is also critically involved in the establishment of high-order chromatin structures and looping. IDR- and phase separation-driven 3D genome (re)organization often goes wrong in disease such as cancer. This review discusses about recent advances in understanding how phase separation of intrinsically disordered proteins (IDPs) modulates chromatin looping and gene expression.
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Affiliation(s)
- Ling Cai
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA,Department of Genetics, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA,Ling Cai Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC27599, USA
| | - Gang Greg Wang
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA,Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA,Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA,CONTACT Gang Greg Wang Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC27599, USA
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12
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Jung N, Kim TK. Spatial transcriptomics in neuroscience. Exp Mol Med 2023; 55:2105-2115. [PMID: 37779145 PMCID: PMC10618223 DOI: 10.1038/s12276-023-01093-y] [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: 02/28/2023] [Revised: 07/07/2023] [Accepted: 07/09/2023] [Indexed: 10/03/2023] Open
Abstract
The brain is one of the most complex living tissue types and is composed of an exceptional diversity of cell types displaying unique functional connectivity. Single-cell RNA sequencing (scRNA-seq) can be used to efficiently map the molecular identities of the various cell types in the brain by providing the transcriptomic profiles of individual cells isolated from the tissue. However, the lack of spatial context in scRNA-seq prevents a comprehensive understanding of how different configurations of cell types give rise to specific functions in individual brain regions and how each distinct cell is connected to form a functional unit. To understand how the various cell types contribute to specific brain functions, it is crucial to correlate the identities of individual cells obtained through scRNA-seq with their spatial information in intact tissue. Spatial transcriptomics (ST) can resolve the complex spatial organization of cell types in the brain and their connectivity. Various ST tools developed during the past decade based on imaging and sequencing technology have permitted the creation of functional atlases of the brain and have pulled the properties of neural circuits into ever-sharper focus. In this review, we present a summary of several ST tools and their applications in neuroscience and discuss the unprecedented insights these tools have made possible.
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Affiliation(s)
- Namyoung Jung
- Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang, Gyeongbuk, 37673, Republic of Korea
| | - Tae-Kyung Kim
- Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang, Gyeongbuk, 37673, Republic of Korea.
- Institute for Convergence Research and Education in Advanced Technology, Yonsei University, Seoul, 03722, Republic of Korea.
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13
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Chen X, Li Y, Li X, Sun J, Czajkowsky DM, Shao Z. Quasi-equilibrium state based quantification of biological macromolecules in single-molecule localization microscopy. Methods Appl Fluoresc 2023; 11:047001. [PMID: 37647910 DOI: 10.1088/2050-6120/acf546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Accepted: 08/30/2023] [Indexed: 09/01/2023]
Abstract
The stoichiometry of molecular components within supramolecular biological complexes is often an important property to understand their biological functioning, particularly within their native environment. While there are well established methods to determine stoichiometryin vitro, it is presently challenging to precisely quantify this propertyin vivo,especially with single molecule resolution that is needed for the characterization stoichiometry heterogeneity. Previous work has shown that optical microscopy can provide some information to this end, but it can be challenging to obtain highly precise measurements at higher densities of fluorophores. Here we provide a simple approach using already established procedures in single-molecule localization microscopy (SMLM) to enable precise quantification of stoichiometry within individual complexes regardless of the density of fluorophores. We show that by focusing on the number of fluorophore detections accumulated during the quasi equilibrium-state of this process, this method yields a 50-fold improvement in precision over values obtained from images with higher densities of active fluorophores. Further, we show that our method yields more correct estimates of stoichiometry with nuclear pore complexes and is easily adaptable to quantify the DNA content with nanodomains of chromatin within individual chromosomes inside cells. Thus, we envision that this straightforward method may become a common approach by which SMLM can be routinely employed for the accurate quantification of subunit stoichiometry within individual complexes within cells.
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Affiliation(s)
- Xuecheng Chen
- Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
| | - Yaqian Li
- State Key Laboratory of Systems Medicine for Cancer, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
| | - Xiaowei Li
- State Key Laboratory of Systems Medicine for Cancer, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
| | - Jielin Sun
- Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
| | - Daniel M Czajkowsky
- State Key Laboratory of Systems Medicine for Cancer, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
| | - Zhifeng Shao
- State Key Laboratory of Systems Medicine for Cancer, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
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14
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Dutta S, Ghosh A, Boettiger AN, Spakowitz AJ. Leveraging polymer modeling to reconstruct chromatin connectivity from live images. Biophys J 2023; 122:3532-3540. [PMID: 37542372 PMCID: PMC10502477 DOI: 10.1016/j.bpj.2023.08.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 06/19/2023] [Accepted: 08/01/2023] [Indexed: 08/06/2023] Open
Abstract
Chromosomal dynamics plays a central role in a number of critical biological processes, such as transcriptional regulation, genetic recombination, and DNA replication. However, visualization of chromatin is generally limited to live imaging of a few fluorescently labeled chromosomal loci or high-resolution reconstruction of multiple loci from a single time frame. To aid in mapping the underlying chromosomal structure based on parsimonious experimental measurements, we present an exact analytical expression for the evolution of the polymer configuration based on a flexible-polymer model, and we propose an algorithm that tracks the polymer configuration from live images of chromatin marked with several fluorescent marks. Our theory identifies the resolution of microscopy needed to achieve high-accuracy tracking for a given spacing of markers, establishing the statistical confidence in the assignment of genome identity to the visualized marks. We then leverage experimental data of locus-tracking measurements to demonstrate the validity of our modeling approach and to establish a basis for the design of experiments with a desired resolution. Altogether, this work provides a computational approach founded on polymer physics that vastly improves the interpretation of in vivo measurements of biopolymer dynamics.
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Affiliation(s)
- Sayantan Dutta
- Department of Chemical Engineering, Stanford University, Stanford, California
| | - Ashesh Ghosh
- Department of Chemical Engineering, Stanford University, Stanford, California
| | | | - Andrew J Spakowitz
- Department of Chemical Engineering, Stanford University, Stanford, California; Department of Materials Science and Engineering, Stanford University, Stanford, California; Program in Biophysics, Stanford University, Stanford, California.
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15
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Dekker J, Alber F, Aufmkolk S, Beliveau BJ, Bruneau BG, Belmont AS, Bintu L, Boettiger A, Calandrelli R, Disteche CM, Gilbert DM, Gregor T, Hansen AS, Huang B, Huangfu D, Kalhor R, Leslie CS, Li W, Li Y, Ma J, Noble WS, Park PJ, Phillips-Cremins JE, Pollard KS, Rafelski SM, Ren B, Ruan Y, Shav-Tal Y, Shen Y, Shendure J, Shu X, Strambio-De-Castillia C, Vertii A, Zhang H, Zhong S. Spatial and temporal organization of the genome: Current state and future aims of the 4D nucleome project. Mol Cell 2023; 83:2624-2640. [PMID: 37419111 PMCID: PMC10528254 DOI: 10.1016/j.molcel.2023.06.018] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 06/10/2023] [Accepted: 06/12/2023] [Indexed: 07/09/2023]
Abstract
The four-dimensional nucleome (4DN) consortium studies the architecture of the genome and the nucleus in space and time. We summarize progress by the consortium and highlight the development of technologies for (1) mapping genome folding and identifying roles of nuclear components and bodies, proteins, and RNA, (2) characterizing nuclear organization with time or single-cell resolution, and (3) imaging of nuclear organization. With these tools, the consortium has provided over 2,000 public datasets. Integrative computational models based on these data are starting to reveal connections between genome structure and function. We then present a forward-looking perspective and outline current aims to (1) delineate dynamics of nuclear architecture at different timescales, from minutes to weeks as cells differentiate, in populations and in single cells, (2) characterize cis-determinants and trans-modulators of genome organization, (3) test functional consequences of changes in cis- and trans-regulators, and (4) develop predictive models of genome structure and function.
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Affiliation(s)
- Job Dekker
- University of Massachusetts Chan Medical School, Boston, MA, USA; Howard Hughes Medical Institute, Chevy Chase, MD, USA.
| | - Frank Alber
- University of California, Los Angeles, Los Angeles, CA, USA
| | | | | | - Benoit G Bruneau
- Gladstone Institutes, San Francisco, CA, USA; University of California, San Francisco, San Francisco, CA, USA
| | | | | | | | | | | | | | | | | | - Bo Huang
- University of California, San Francisco, San Francisco, CA, USA
| | - Danwei Huangfu
- Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Reza Kalhor
- Johns Hopkins University, Baltimore, MD, USA
| | | | - Wenbo Li
- University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Yun Li
- University of North Carolina, Gillings School of Global Public Health, Chapel Hill, NC, USA
| | - Jian Ma
- Carnegie Mellon University, Pittsburgh, PA, USA
| | | | | | | | - Katherine S Pollard
- Gladstone Institutes, San Francisco, CA, USA; University of California, San Francisco, San Francisco, CA, USA; Chan Zuckerberg Biohub, San Francisco, San Francisco, CA, USA
| | | | - Bing Ren
- University of California, San Diego, La Jolla, CA, USA
| | - Yijun Ruan
- Zhejiang University, Hangzhou, Zhejiang, China
| | | | - Yin Shen
- University of California, San Francisco, San Francisco, CA, USA
| | | | - Xiaokun Shu
- University of California, San Francisco, San Francisco, CA, USA
| | | | | | | | - Sheng Zhong
- University of California, San Diego, La Jolla, CA, USA.
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16
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Mirny LA. Chromosome and protein folding: In search for unified principles. Curr Opin Struct Biol 2023; 81:102610. [PMID: 37327690 DOI: 10.1016/j.sbi.2023.102610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Revised: 04/24/2023] [Accepted: 04/24/2023] [Indexed: 06/18/2023]
Abstract
Structural biology has traditionally focused on the structures of proteins, short nucleic acids, small molecules, and their complexes. However, it is now widely recognized that the 3D organization of chromosomes should also be included in this list, despite significant differences in scale and complexity of organization. Here we highlight some notable similarities between the folding processes that shape proteins and chromosomes. Both biomolecules are folded by two types of processes: the affinity-mediated interactions, and by active (ATP-dependent) processes. Both chromosome and proteins in vivo can have partially unstructured and non-equilibrium ensembles with yet to be understood functional roles. By analyzing these biological systems in parallel, we can uncover universal principles of biomolecular organization that transcend specific biopolymers.
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Affiliation(s)
- Leonid A Mirny
- Institute for Medical Engineering and Science, and Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
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17
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Harun A, Liu H, Song S, Asghar S, Wen X, Fang Z, Chen C. Oligonucleotide Fluorescence In Situ Hybridization: An Efficient Chromosome Painting Method in Plants. PLANTS (BASEL, SWITZERLAND) 2023; 12:2816. [PMID: 37570972 PMCID: PMC10420648 DOI: 10.3390/plants12152816] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 07/19/2023] [Accepted: 07/27/2023] [Indexed: 08/13/2023]
Abstract
Fluorescence in situ hybridization (FISH) is an indispensable technique for studying chromosomes in plants. However, traditional FISH methods, such as BAC, rDNA, tandem repeats, and distributed repetitive sequence probe-based FISH, have certain limitations, including difficulties in probe synthesis, low sensitivity, cross-hybridization, and limited resolution. In contrast, oligo-based FISH represents a more efficient method for chromosomal studies in plants. Oligo probes are computationally designed and synthesized for any plant species with a sequenced genome and are suitable for single and repetitive DNA sequences, entire chromosomes, or chromosomal segments. Furthermore, oligo probes used in the FISH experiment provide high specificity, resolution, and multiplexing. Moreover, oligo probes made from one species are applicable for studying other genetically and taxonomically related species whose genome has not been sequenced yet, facilitating molecular cytogenetic studies of non-model plants. However, there are some limitations of oligo probes that should be considered, such as requiring prior knowledge of the probe design process and FISH signal issues with shorter probes of background noises during oligo-FISH experiments. This review comprehensively discusses de novo oligo probe synthesis with more focus on single-copy DNA sequences, preparation, improvement, and factors that affect oligo-FISH efficiency. Furthermore, this review highlights recent applications of oligo-FISH in a wide range of plant chromosomal studies.
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Affiliation(s)
- Arrashid Harun
- Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), Institute of Rice Industry Technology Research, College of Agricultural Sciences, Guizhou University, Guiyang 550025, China;
- Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), Institute of Agro-Bioengineering, College of Life Science, Guizhou University, Guiyang 550025, China; (S.A.); (X.W.)
- National Key Laboratory for Germplasm Innovation and Utilization for Fruit and Vegetable Horticultural Crops, Hubei Hongshan Laboratory, Wuhan 430070, China; (H.L.); (S.S.)
| | - Hui Liu
- National Key Laboratory for Germplasm Innovation and Utilization for Fruit and Vegetable Horticultural Crops, Hubei Hongshan Laboratory, Wuhan 430070, China; (H.L.); (S.S.)
| | - Shipeng Song
- National Key Laboratory for Germplasm Innovation and Utilization for Fruit and Vegetable Horticultural Crops, Hubei Hongshan Laboratory, Wuhan 430070, China; (H.L.); (S.S.)
| | - Sumeera Asghar
- Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), Institute of Agro-Bioengineering, College of Life Science, Guizhou University, Guiyang 550025, China; (S.A.); (X.W.)
- National Key Laboratory for Germplasm Innovation and Utilization for Fruit and Vegetable Horticultural Crops, Hubei Hongshan Laboratory, Wuhan 430070, China; (H.L.); (S.S.)
| | - Xiaopeng Wen
- Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), Institute of Agro-Bioengineering, College of Life Science, Guizhou University, Guiyang 550025, China; (S.A.); (X.W.)
| | - Zhongming Fang
- Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), Institute of Rice Industry Technology Research, College of Agricultural Sciences, Guizhou University, Guiyang 550025, China;
| | - Chunli Chen
- Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), Institute of Rice Industry Technology Research, College of Agricultural Sciences, Guizhou University, Guiyang 550025, China;
- Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), Institute of Agro-Bioengineering, College of Life Science, Guizhou University, Guiyang 550025, China; (S.A.); (X.W.)
- National Key Laboratory for Germplasm Innovation and Utilization for Fruit and Vegetable Horticultural Crops, Hubei Hongshan Laboratory, Wuhan 430070, China; (H.L.); (S.S.)
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18
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Pradhan S, Apaydin S, Bucevičius J, Gerasimaitė R, Kostiuk G, Lukinavičius G. Sequence-specific DNA labelling for fluorescence microscopy. Biosens Bioelectron 2023; 230:115256. [PMID: 36989663 DOI: 10.1016/j.bios.2023.115256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 03/04/2023] [Accepted: 03/21/2023] [Indexed: 03/29/2023]
Abstract
The preservation of nucleus structure during microscopy imaging is a top priority for understanding chromatin organization, genome dynamics, and gene expression regulation. In this review, we summarize the sequence-specific DNA labelling methods that can be used for imaging in fixed and/or living cells without harsh treatment and DNA denaturation: (i) hairpin polyamides, (ii) triplex-forming oligonucleotides, (iii) dCas9 proteins, (iv) transcription activator-like effectors (TALEs) and (v) DNA methyltransferases (MTases). All these techniques are capable of identifying repetitive DNA loci and robust probes are available for telomeres and centromeres, but visualizing single-copy sequences is still challenging. In our futuristic vision, we see gradual replacement of the historically important fluorescence in situ hybridization (FISH) by less invasive and non-destructive methods compatible with live cell imaging. Combined with super-resolution fluorescence microscopy, these methods will open the possibility to look into unperturbed structure and dynamics of chromatin in living cells, tissues and whole organisms.
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19
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Salataj E, Spilianakis CG, Chaumeil J. Single-cell detection of primary transcripts, their genomic loci and nuclear factors by 3D immuno-RNA/DNA FISH in T cells. Front Immunol 2023; 14:1156077. [PMID: 37215121 PMCID: PMC10193148 DOI: 10.3389/fimmu.2023.1156077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 04/12/2023] [Indexed: 05/24/2023] Open
Abstract
Over the past decades, it has become increasingly clear that higher order chromatin folding and organization within the nucleus is involved in the regulation of genome activity and serves as an additional epigenetic mechanism that modulates cellular functions and gene expression programs in diverse biological processes. In particular, dynamic allelic interactions and nuclear locations can be of functional importance during the process of lymphoid differentiation and the regulation of immune responses. Analyses of the proximity between chromatin and/or nuclear regions can be performed on populations of cells with high-throughput sequencing approaches such as chromatin conformation capture ("3C"-based) or DNA adenine methyltransferase identification (DamID) methods, or, in individual cells, by the simultaneous visualization of genomic loci, their primary transcripts and nuclear compartments within the 3-dimensional nuclear space using Fluorescence In Situ Hybridization (FISH) and immunostaining. Here, we present a detailed protocol to simultaneously detect nascent RNA transcripts (3D RNA FISH), their genomic loci (3D DNA FISH) and/or their chromosome territories (CT paint DNA FISH) combined with the antibody-based detection of various nuclear factors (immunofluorescence). We delineate the application and effectiveness of this robust and reproducible protocol in several murine T lymphocyte subtypes (from differentiating thymic T cells, to activated splenic and peripheral T cells) as well as other murine cells, including embryonic stem cells, B cells, megakaryocytes and macrophages.
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Affiliation(s)
- Eralda Salataj
- Université Paris Cité, Institut Cochin, INSERM, CNRS, Paris, France
- Institute of Molecular Biology and Biotechnology-Foundation for Research and Technology Hellas, Heraklion, Crete, Greece
| | - Charalampos G. Spilianakis
- Institute of Molecular Biology and Biotechnology-Foundation for Research and Technology Hellas, Heraklion, Crete, Greece
- Department of Biology, University of Crete, Heraklion, Crete, Greece
| | - Julie Chaumeil
- Université Paris Cité, Institut Cochin, INSERM, CNRS, Paris, France
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20
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Chen LF, Lee J, Boettiger A. Recent progress and challenges in single-cell imaging of enhancer-promoter interaction. Curr Opin Genet Dev 2023; 79:102023. [PMID: 36854248 DOI: 10.1016/j.gde.2023.102023] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 01/13/2023] [Accepted: 01/25/2023] [Indexed: 02/27/2023]
Abstract
In the past two years, approaches relying on high-resolution microscopy and live-cell imaging have increasingly contributed to our understanding of the 3D genome organization and its importance for transcriptional control. Here, we describe recent progress that has highlighted how flexible and heterogeneous 3D chromatin structure is, on the length scales relevant to transcriptional control. We describe work that has investigated how robust transcriptional outcomes may be derived from such flexible organization without the need for clearly distinct structures in active and silent cells. We survey the latest state of the art in directly observing the dynamics of chromatin interactions, and suggest how some recent, apparently contradictory conclusions may be reconciled.
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Affiliation(s)
- Liang-Fu Chen
- Department of Chemical and Systems Biology, Stanford University, USA
| | - Joo Lee
- Department of Developmental Biology, Stanford University, USA
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21
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Li Y, Matsunaga S. Various Strategies for Improved Signal-to-Noise Ratio in CRISPR-Based Live Cell Imaging. CYTOLOGIA 2023. [DOI: 10.1508/cytologia.88.3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/28/2023]
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22
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Ball ML, Koestler SA, Muresan L, Rehman SA, O’Holleran K, White R. The anatomy of transcriptionally active chromatin loops in Drosophila primary spermatocytes using super-resolution microscopy. PLoS Genet 2023; 19:e1010654. [PMID: 36867662 PMCID: PMC10016678 DOI: 10.1371/journal.pgen.1010654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 03/15/2023] [Accepted: 02/04/2023] [Indexed: 03/04/2023] Open
Abstract
While the biochemistry of gene transcription has been well studied, our understanding of how this process is organised in 3D within the intact nucleus is less well understood. Here we investigate the structure of actively transcribed chromatin and the architecture of its interaction with active RNA polymerase. For this analysis, we have used super-resolution microscopy to image the Drosophila melanogaster Y loops which represent huge, several megabases long, single transcription units. The Y loops provide a particularly amenable model system for transcriptionally active chromatin. We find that, although these transcribed loops are decondensed they are not organised as extended 10nm fibres, but rather they largely consist of chains of nucleosome clusters. The average width of each cluster is around 50nm. We find that foci of active RNA polymerase are generally located off the main fibre axis on the periphery of the nucleosome clusters. Foci of RNA polymerase and nascent transcripts are distributed around the Y loops rather than being clustered in individual transcription factories. However, as the RNA polymerase foci are considerably less prevalent than the nucleosome clusters, the organisation of this active chromatin into chains of nucleosome clusters is unlikely to be determined by the activity of the polymerases transcribing the Y loops. These results provide a foundation for understanding the topological relationship between chromatin and the process of gene transcription.
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Affiliation(s)
- Madeleine L. Ball
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Site, Cambridge, United Kingdom
| | - Stefan A. Koestler
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Site, Cambridge, United Kingdom
| | - Leila Muresan
- Cambridge Advanced Imaging Centre, University of Cambridge, Downing Site, Cambridge, United Kingdom
| | - Sohaib Abdul Rehman
- Cambridge Advanced Imaging Centre, University of Cambridge, Downing Site, Cambridge, United Kingdom
| | - Kevin O’Holleran
- Cambridge Advanced Imaging Centre, University of Cambridge, Downing Site, Cambridge, United Kingdom
| | - Robert White
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Site, Cambridge, United Kingdom
- * E-mail:
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23
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Shi G, Thirumalai D. A maximum-entropy model to predict 3D structural ensembles of chromatin from pairwise distances with applications to interphase chromosomes and structural variants. Nat Commun 2023; 14:1150. [PMID: 36854665 PMCID: PMC9974990 DOI: 10.1038/s41467-023-36412-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Accepted: 01/31/2023] [Indexed: 03/02/2023] Open
Abstract
The principles that govern the organization of genomes, which are needed for an understanding of how chromosomes are packaged and function in eukaryotic cells, could be deciphered if the three-dimensional (3D) structures are known. Recently, single-cell imaging techniques have been developed to determine the 3D coordinates of genomic loci in vivo. Here, we introduce a computational method (Distance Matrix to Ensemble of Structures, DIMES), based on the maximum entropy principle, with experimental pairwise distances between loci as constraints, to generate a unique ensemble of 3D chromatin structures. Using the ensemble of structures, we quantitatively account for the distribution of pairwise distances, three-body co-localization, and higher-order interactions. The DIMES method can be applied to both small and chromosome-scale imaging data to quantify the extent of heterogeneity and fluctuations in the shapes across various length scales. We develop a perturbation method in conjunction with DIMES to predict the changes in 3D structures from structural variations. Our method also reveals quantitative differences between the 3D structures inferred from Hi-C and those measured in imaging experiments. Finally, the physical interpretation of the parameters extracted from DIMES provides insights into the origin of phase separation between euchromatin and heterochromatin domains.
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Affiliation(s)
- Guang Shi
- Department of Chemistry, University of Texas at Austin, Austin, Texas, 78712, USA. .,Department of Materials Science, University of Illinois, Urbana, Illinois, 61801, USA.
| | - D Thirumalai
- Department of Chemistry, University of Texas at Austin, Austin, Texas, 78712, USA. .,Department of Physics, University of Texas at Austin, Austin, Texas, 78712, USA.
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24
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Kim S, Wysocka J. Deciphering the multi-scale, quantitative cis-regulatory code. Mol Cell 2023; 83:373-392. [PMID: 36693380 PMCID: PMC9898153 DOI: 10.1016/j.molcel.2022.12.032] [Citation(s) in RCA: 57] [Impact Index Per Article: 57.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 12/29/2022] [Accepted: 12/30/2022] [Indexed: 01/24/2023]
Abstract
Uncovering the cis-regulatory code that governs when and how much each gene is transcribed in a given genome and cellular state remains a central goal of biology. Here, we discuss major layers of regulation that influence how transcriptional outputs are encoded by DNA sequence and cellular context. We first discuss how transcription factors bind specific DNA sequences in a dosage-dependent and cooperative manner and then proceed to the cofactors that facilitate transcription factor function and mediate the activity of modular cis-regulatory elements such as enhancers, silencers, and promoters. We then consider the complex and poorly understood interplay of these diverse elements within regulatory landscapes and its relationships with chromatin states and nuclear organization. We propose that a mechanistically informed, quantitative model of transcriptional regulation that integrates these multiple regulatory layers will be the key to ultimately cracking the cis-regulatory code.
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Affiliation(s)
- Seungsoo Kim
- Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA; Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Joanna Wysocka
- Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA; Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA.
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25
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van Mierlo G, Pushkarev O, Kribelbauer JF, Deplancke B. Chromatin modules and their implication in genomic organization and gene regulation. Trends Genet 2023; 39:140-153. [PMID: 36549923 DOI: 10.1016/j.tig.2022.11.003] [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: 06/08/2022] [Revised: 11/04/2022] [Accepted: 11/27/2022] [Indexed: 12/24/2022]
Abstract
Regulation of gene expression is a complex but highly guided process. While genomic technologies and computational approaches have allowed high-throughput mapping of cis-regulatory elements (CREs) and their interactions in 3D, their precise role in regulating gene expression remains obscure. Recent complementary observations revealed that interactions between CREs frequently result in the formation of small-scale functional modules within topologically associating domains. Such chromatin modules likely emerge from a complex interplay between regulatory machineries assembled at CREs, including site-specific binding of transcription factors. Here, we review the methods that allow identifying chromatin modules, summarize possible mechanisms that steer CRE interactions within these modules, and discuss outstanding challenges to uncover how chromatin modules fit in our current understanding of the functional 3D genome.
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Affiliation(s)
- Guido van Mierlo
- Laboratory of Systems Biology and Genetics, Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland; Swiss Institute of Bioinformatics (SIB), Lausanne, Switzerland
| | - Olga Pushkarev
- Laboratory of Systems Biology and Genetics, Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland; Swiss Institute of Bioinformatics (SIB), Lausanne, Switzerland
| | - Judith F Kribelbauer
- Laboratory of Systems Biology and Genetics, Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland; Swiss Institute of Bioinformatics (SIB), Lausanne, Switzerland
| | - Bart Deplancke
- Laboratory of Systems Biology and Genetics, Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland; Swiss Institute of Bioinformatics (SIB), Lausanne, Switzerland.
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26
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Abstract
In animals, the sequences for controlling gene expression do not concentrate just at the transcription start site of genes, but are frequently thousands to millions of base pairs distal to it. The interaction of these sequences with one another and their transcription start sites is regulated by factors that shape the three-dimensional (3D) organization of the genome within the nucleus. Over the past decade, indirect tools exploiting high-throughput DNA sequencing have helped to map this 3D organization, have identified multiple key regulators of its structure and, in the process, have substantially reshaped our view of how 3D genome architecture regulates transcription. Now, new tools for high-throughput super-resolution imaging of chromatin have directly visualized the 3D chromatin organization, settling some debates left unresolved by earlier indirect methods, challenging some earlier models of regulatory specificity and creating hypotheses about the role of chromatin structure in transcriptional regulation.
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27
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Maloshenok LG, Abushinova GA, Ryazanova AY, Bruskin SA, Zherdeva VV. Visualizing the Nucleome Using the CRISPR–Cas9 System: From in vitro to in vivo. BIOCHEMISTRY (MOSCOW) 2023; 88:S123-S149. [PMID: 37069118 PMCID: PMC9940691 DOI: 10.1134/s0006297923140080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
One of the latest methods in modern molecular biology is labeling genomic loci in living cells using fluorescently labeled Cas protein. The NIH Foundation has made the mapping of the 4D nucleome (the three-dimensional nucleome on a timescale) a priority in the studies aimed to improve our understanding of chromatin organization. Fluorescent methods based on CRISPR-Cas are a significant step forward in visualization of genomic loci in living cells. This approach can be used for studying epigenetics, cell cycle, cellular response to external stimuli, rearrangements during malignant cell transformation, such as chromosomal translocations or damage, as well as for genome editing. In this review, we focused on the application of CRISPR-Cas fluorescence technologies as components of multimodal imaging methods for in vivo mapping of chromosomal loci, in particular, attribution of fluorescence signal to morphological and anatomical structures in a living organism. The review discusses the approaches to the highly sensitive, high-precision labeling of CRISPR-Cas components, delivery of genetically engineered constructs into cells and tissues, and promising methods for molecular imaging.
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Affiliation(s)
- Liliya G Maloshenok
- Bach Institute of Biochemistry, Federal Research Center for Biotechnology of the Russian Academy of Sciences, Moscow, 119071, Russia
- Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, 119991, Russia
| | - Gerel A Abushinova
- Bach Institute of Biochemistry, Federal Research Center for Biotechnology of the Russian Academy of Sciences, Moscow, 119071, Russia
- Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, 119991, Russia
| | - Alexandra Yu Ryazanova
- Bach Institute of Biochemistry, Federal Research Center for Biotechnology of the Russian Academy of Sciences, Moscow, 119071, Russia
| | - Sergey A Bruskin
- Bach Institute of Biochemistry, Federal Research Center for Biotechnology of the Russian Academy of Sciences, Moscow, 119071, Russia
- Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, 119991, Russia
| | - Victoria V Zherdeva
- Bach Institute of Biochemistry, Federal Research Center for Biotechnology of the Russian Academy of Sciences, Moscow, 119071, Russia.
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28
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Viushkov VS, Lomov NA, Rubtsov MA, Vassetzky YS. Visualizing the Genome: Experimental Approaches for Live-Cell Chromatin Imaging. Cells 2022; 11:cells11244086. [PMID: 36552850 PMCID: PMC9776900 DOI: 10.3390/cells11244086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 12/07/2022] [Accepted: 12/13/2022] [Indexed: 12/24/2022] Open
Abstract
Over the years, our vision of the genome has changed from a linear molecule to that of a complex 3D structure that follows specific patterns and possesses a hierarchical organization. Currently, genomics is becoming "four-dimensional": our attention is increasingly focused on the study of chromatin dynamics over time, in the fourth dimension. Recent methods for visualizing the movements of chromatin loci in living cells by targeting fluorescent proteins can be divided into two groups. The first group requires the insertion of a special sequence into the locus of interest, to which proteins that recognize the sequence are recruited (e.g., FROS and ParB-INT methods). In the methods of the second approach, "programmed" proteins are targeted to the locus of interest (i.e., systems based on CRISPR/Cas, TALE, and zinc finger proteins). In the present review, we discuss these approaches, examine their strengths and weaknesses, and identify the key scientific problems that can be studied using these methods.
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Affiliation(s)
- Vladimir S. Viushkov
- Department of Molecular Biology, Faculty of Biology, Lomonosov Moscow State University, 119234 Moscow, Russia
| | - Nikolai A. Lomov
- Department of Molecular Biology, Faculty of Biology, Lomonosov Moscow State University, 119234 Moscow, Russia
| | - Mikhail A. Rubtsov
- Department of Molecular Biology, Faculty of Biology, Lomonosov Moscow State University, 119234 Moscow, Russia
- Department of Biochemistry, Center for Industrial Technologies and Entrepreneurship, I.M. Sechenov First Moscow State Medical University (Sechenov University), 119435 Moscow, Russia
| | - Yegor S. Vassetzky
- CNRS UMR9018, Université Paris-Saclay, Gustave Roussy, 94805 Villejuif, France
- Koltzov Institute of Developmental Biology, Russian Academy of Sciences, 119334 Moscow, Russia
- Correspondence:
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29
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Randall RS, Jourdain C, Nowicka A, Kaduchová K, Kubová M, Ayoub MA, Schubert V, Tatout C, Colas I, Kalyanikrishna, Desset S, Mermet S, Boulaflous-Stevens A, Kubalová I, Mandáková T, Heckmann S, Lysak MA, Panatta M, Santoro R, Schubert D, Pecinka A, Routh D, Baroux C. Image analysis workflows to reveal the spatial organization of cell nuclei and chromosomes. Nucleus 2022; 13:277-299. [PMID: 36447428 PMCID: PMC9754023 DOI: 10.1080/19491034.2022.2144013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Nucleus, chromatin, and chromosome organization studies heavily rely on fluorescence microscopy imaging to elucidate the distribution and abundance of structural and regulatory components. Three-dimensional (3D) image stacks are a source of quantitative data on signal intensity level and distribution and on the type and shape of distribution patterns in space. Their analysis can lead to novel insights that are otherwise missed in qualitative-only analyses. Quantitative image analysis requires specific software and workflows for image rendering, processing, segmentation, setting measurement points and reference frames and exporting target data before further numerical processing and plotting. These tasks often call for the development of customized computational scripts and require an expertise that is not broadly available to the community of experimental biologists. Yet, the increasing accessibility of high- and super-resolution imaging methods fuels the demand for user-friendly image analysis workflows. Here, we provide a compendium of strategies developed by participants of a training school from the COST action INDEPTH to analyze the spatial distribution of nuclear and chromosomal signals from 3D image stacks, acquired by diffraction-limited confocal microscopy and super-resolution microscopy methods (SIM and STED). While the examples make use of one specific commercial software package, the workflows can easily be adapted to concurrent commercial and open-source software. The aim is to encourage biologists lacking custom-script-based expertise to venture into quantitative image analysis and to better exploit the discovery potential of their images.Abbreviations: 3D FISH: three-dimensional fluorescence in situ hybridization; 3D: three-dimensional; ASY1: ASYNAPTIC 1; CC: chromocenters; CO: Crossover; DAPI: 4',6-diamidino-2-phenylindole; DMC1: DNA MEIOTIC RECOMBINASE 1; DSB: Double-Strand Break; FISH: fluorescence in situ hybridization; GFP: GREEN FLUORESCENT PROTEIN; HEI10: HUMAN ENHANCER OF INVASION 10; NCO: Non-Crossover; NE: Nuclear Envelope; Oligo-FISH: oligonucleotide fluorescence in situ hybridization; RNPII: RNA Polymerase II; SC: Synaptonemal Complex; SIM: structured illumination microscopy; ZMM (ZIP: MSH4: MSH5 and MER3 proteins); ZYP1: ZIPPER-LIKE PROTEIN 1.
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Affiliation(s)
- Ricardo S Randall
- Department of Plant and Microbial Biology, Zürich-Basel Plant Science Center, University of Zürich, Zürich, Switzerland
| | | | - Anna Nowicka
- Centre of the Region Haná for Biotechnological and Agricultural Research (CRH), Institute of Experimental Botany, v. v. i. (IEB), Olomouc, Czech Republic
| | - Kateřina Kaduchová
- Centre of the Region Haná for Biotechnological and Agricultural Research (CRH), Institute of Experimental Botany, v. v. i. (IEB), Olomouc, Czech Republic
| | - Michaela Kubová
- Central European Institute of Technology (CEITEC) and Department of Experimental Biology, Masaryk University, Brno, Czech Republic
| | - Mohammad A. Ayoub
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, D-06466Seeland, Germany
| | - Veit Schubert
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, D-06466Seeland, Germany
| | - Christophe Tatout
- Institut Génétique, Reproduction et Développement (GReD), Université Clermont Auvergne, CNRS, INSERM, 63001Clermont-Ferrand, France
| | - Isabelle Colas
- The James Hutton Institute, Errol Road, Invergowrie, DD2 5DA, Scotland UK
| | | | - Sophie Desset
- Institut Génétique, Reproduction et Développement (GReD), Université Clermont Auvergne, CNRS, INSERM, 63001Clermont-Ferrand, France
| | - Sarah Mermet
- Institut Génétique, Reproduction et Développement (GReD), Université Clermont Auvergne, CNRS, INSERM, 63001Clermont-Ferrand, France
| | - Aurélia Boulaflous-Stevens
- Institut Génétique, Reproduction et Développement (GReD), Université Clermont Auvergne, CNRS, INSERM, 63001Clermont-Ferrand, France
| | - Ivona Kubalová
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, D-06466Seeland, Germany
| | - Terezie Mandáková
- Central European Institute of Technology (CEITEC) and Department of Experimental Biology, Masaryk University, Brno, Czech Republic
| | - Stefan Heckmann
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, D-06466Seeland, Germany
| | - Martin A. Lysak
- Central European Institute of Technology (CEITEC) and National Centre for Biomolecular Research, Masaryk University, Brno, Czech Republic
| | - Martina Panatta
- Department of Molecular Mechanisms of Disease, DMMD, University of Zürich, Zürich, Switzerland
| | - Raffaella Santoro
- Department of Molecular Mechanisms of Disease, DMMD, University of Zürich, Zürich, Switzerland
| | | | - Ales Pecinka
- Centre of the Region Haná for Biotechnological and Agricultural Research (CRH), Institute of Experimental Botany, v. v. i. (IEB), Olomouc, Czech Republic
| | - Devin Routh
- Service and Support for Science IT (S3IT), Universität Zürich, Zürich, Switzerland
| | - Célia Baroux
- Department of Plant and Microbial Biology, Zürich-Basel Plant Science Center, University of Zürich, Zürich, Switzerland,CONTACT Célia Baroux Department of Plant and Microbial Biology, Zürich-Basel Plant Science Center, University of Zürich, Zürich, Switzerland
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30
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Mansisidor AR, Risca VI. Chromatin accessibility: methods, mechanisms, and biological insights. Nucleus 2022; 13:236-276. [PMID: 36404679 PMCID: PMC9683059 DOI: 10.1080/19491034.2022.2143106] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 10/23/2022] [Accepted: 10/30/2022] [Indexed: 11/22/2022] Open
Abstract
Access to DNA is a prerequisite to the execution of essential cellular processes that include transcription, replication, chromosomal segregation, and DNA repair. How the proteins that regulate these processes function in the context of chromatin and its dynamic architectures is an intensive field of study. Over the past decade, genome-wide assays and new imaging approaches have enabled a greater understanding of how access to the genome is regulated by nucleosomes and associated proteins. Additional mechanisms that may control DNA accessibility in vivo include chromatin compaction and phase separation - processes that are beginning to be understood. Here, we review the ongoing development of accessibility measurements, we summarize the different molecular and structural mechanisms that shape the accessibility landscape, and we detail the many important biological functions that are linked to chromatin accessibility.
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Affiliation(s)
- Andrés R. Mansisidor
- Laboratory of Genome Architecture and Dynamics, The Rockefeller University, New York, NY
| | - Viviana I. Risca
- Laboratory of Genome Architecture and Dynamics, The Rockefeller University, New York, NY
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31
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Fujita Y, Pather SR, Ming GL, Song H. 3D spatial genome organization in the nervous system: From development and plasticity to disease. Neuron 2022; 110:2902-2915. [PMID: 35777365 PMCID: PMC9509413 DOI: 10.1016/j.neuron.2022.06.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 03/15/2022] [Accepted: 06/03/2022] [Indexed: 01/03/2023]
Abstract
Chromatin is organized into multiscale three-dimensional structures, including chromosome territories, A/B compartments, topologically associating domains, and chromatin loops. This hierarchically organized genomic architecture regulates gene transcription, which, in turn, is essential for various biological processes during brain development and adult plasticity. Here, we review different aspects of spatial genome organization and their functions in regulating gene expression in the nervous system, as well as their dysregulation in brain disorders. We also highlight new technologies to probe and manipulate chromatin architecture and discuss how investigating spatial genome organization can lead to a better understanding of the nervous system and associated disorders.
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Affiliation(s)
- Yuki Fujita
- Department of Neuroscience, Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Developmental Biology, Faculty of Medicine, Shimane University, Izumo City, Shimane 693-8501, Japan.
| | - Sarshan R Pather
- Department of Neuroscience, Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Cell and Molecular Biology Graduate Group, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Guo-Li Ming
- Department of Neuroscience, Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Hongjun Song
- Department of Neuroscience, Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; The Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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32
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Stefanucci L, Frontini M. Non-coding genetic variation in regulatory elements determines thrombosis and hemostasis phenotypes. J Thromb Haemost 2022; 20:1759-1765. [PMID: 35514262 PMCID: PMC9540108 DOI: 10.1111/jth.15754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 04/27/2022] [Accepted: 05/02/2022] [Indexed: 11/26/2022]
Abstract
Since the early inception of genome-wide association studies (GWAS), it became clear that, in all diseases or traits studied, most genetic variants are likely to exert their effect on gene expression mainly by altering the function of regulatory elements. At the same time, the regulation of the gene expression field broadened its boundaries, from the univocal relationship between regulatory elements and genes to include genome organization, long-range DNA interactions, and epigenetics. Next-generation sequencing has introduced genome-wide approaches that have greatly improved our understanding of the general principles of gene expression. However, elucidating how these apply in every single genomic locus still requires painstaking experimental work, in which several independent lines of evidence are required, and often this is helped by rare genetic variants in individuals with rare diseases. This review will focus on the non-coding features of the genome involved in transcriptional regulation, that when altered, leads to known cases of inherited (familial) thrombotic and hemostatic phenotypes, emphasizing the role of enhancers and super-enhancers.
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Affiliation(s)
- Luca Stefanucci
- Department of HaematologyUniversity of Cambridge, Cambridge Biomedical CampusCambridgeUK
- National Health Service (NHS) Blood and TransplantCambridge Biomedical CampusCambridgeUK
- British Heart Foundation, Cambridge Centre for Research ExcellenceUniversity of Cambridge, Cambridge Biomedical CampusCambridgeUK
| | - Mattia Frontini
- Department of HaematologyUniversity of Cambridge, Cambridge Biomedical CampusCambridgeUK
- National Health Service (NHS) Blood and TransplantCambridge Biomedical CampusCambridgeUK
- British Heart Foundation, Cambridge Centre for Research ExcellenceUniversity of Cambridge, Cambridge Biomedical CampusCambridgeUK
- Institute of Biomedical & Clinical Science, College of Medicine and HealthUniversity of Exeter Medical SchoolExeterUK
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33
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The era of 3D and spatial genomics. Trends Genet 2022; 38:1062-1075. [PMID: 35680466 DOI: 10.1016/j.tig.2022.05.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 05/10/2022] [Accepted: 05/11/2022] [Indexed: 12/28/2022]
Abstract
Over a decade ago the advent of high-throughput chromosome conformation capture (Hi-C) sparked a new era of 3D genomics. Since then the number of methods for mapping the 3D genome has flourished, enabling an ever-increasing understanding of how DNA is packaged in the nucleus and how the spatiotemporal organization of the genome orchestrates its vital functions. More recently, the next generation of spatial genomics technologies has begun to reveal how genome sequence and 3D genome organization vary between cells in their tissue context. We summarize how the toolkit for charting genome topology has evolved over the past decade and discuss how new technological developments are advancing the field of 3D and spatial genomics.
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34
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Interplay between regulatory elements and chromatin topology in cellular lineage determination. Trends Genet 2022; 38:1048-1061. [DOI: 10.1016/j.tig.2022.05.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 05/02/2022] [Accepted: 05/12/2022] [Indexed: 11/16/2022]
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35
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Wang J, Hu C, Chen X, Li Y, Sun J, Czajkowsky DM, Shao Z. Single-Molecule Micromanipulation and Super-Resolution Imaging Resolve Nanodomains Underlying Chromatin Folding in Mitotic Chromosomes. ACS NANO 2022; 16:8030-8039. [PMID: 35485433 DOI: 10.1021/acsnano.2c01025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The folding of interphase chromatin into highly compact mitotic chromosomes is one of the most recognizable changes during the cell cycle. However, the structural organization underlying this drastic compaction remains elusive. Here, we combine several super resolution methods, including structured illumination microscopy (SIM), binding-activated localization microscopy (BALM), and atomic force microscopy (AFM), to examine the structural details of the DNA within the mitotic chromosome, both in the native state and after up to 30-fold extension using single-molecule micromanipulation. Images of native chromosomes reveal widespread ∼125 nm compact granules (CGs) throughout the metaphase chromosome. However, at maximal extensions, we find exclusively ∼90 nm domains (mitotic nanodomains, MNDs) that are unexpectedly resistant to extensive forces of tens of nanonewtons. The DNA content of the MNDs is estimated to be predominantly ∼80 kb, which is comparable to the size of the inner loops predicted by a recent nested loop model of the mitotic chromosome. With this DNA content, the total volume expected of the human genome assuming closely packed MNDs is nearly identical to what is observed. Thus, altogether, these results suggest that these mechanically stable MNDs, and their higher-order assembly into CGs, are the dominant higher-level structures that underlie the compaction of chromatin from interphase to metaphase.
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Affiliation(s)
- Jiabin Wang
- Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Chuansheng Hu
- State Key Laboratory for Oncogenes and Bio-ID Center, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Xuecheng Chen
- Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yaqian Li
- State Key Laboratory for Oncogenes and Bio-ID Center, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Jielin Sun
- Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Daniel M Czajkowsky
- State Key Laboratory for Oncogenes and Bio-ID Center, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Zhifeng Shao
- State Key Laboratory for Oncogenes and Bio-ID Center, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
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36
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Domb K, Wang N, Hummel G, Liu C. Spatial Features and Functional Implications of Plant 3D Genome Organization. ANNUAL REVIEW OF PLANT BIOLOGY 2022; 73:173-200. [PMID: 35130445 DOI: 10.1146/annurev-arplant-102720-022810] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The advent of high-throughput sequencing-based methods for chromatin conformation, accessibility, and immunoprecipitation assays has been a turning point in 3D genomics. Altogether, these new tools have been pushing upward the interpretation of pioneer cytogenetic evidence for a higher order in chromatin packing. Here, we review the latest development in our understanding of plant spatial genome structures and different levels of organization and discuss their functional implications. Then, we spotlight the complexity of organellar (i.e., mitochondria and plastids) genomes and discuss their 3D packing into nucleoids. Finally, we propose unaddressed research axes to investigate functional links between chromatin-like dynamics and transcriptional regulation within organellar nucleoids.
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Affiliation(s)
- Katherine Domb
- Institute of Biology, University of Hohenheim, Stuttgart, Germany;
| | - Nan Wang
- Institute of Biology, University of Hohenheim, Stuttgart, Germany;
| | - Guillaume Hummel
- Institute of Biology, University of Hohenheim, Stuttgart, Germany;
| | - Chang Liu
- Institute of Biology, University of Hohenheim, Stuttgart, Germany;
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37
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Super-resolution visualization of chromatin loop folding in human lymphoblastoid cells using interferometric photoactivated localization microscopy. Sci Rep 2022; 12:8582. [PMID: 35595799 PMCID: PMC9122977 DOI: 10.1038/s41598-022-12568-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Accepted: 05/10/2022] [Indexed: 11/18/2022] Open
Abstract
The three-dimensional (3D) genome structure plays a fundamental role in gene regulation and cellular functions. Recent studies in 3D genomics inferred the very basic functional chromatin folding structures known as chromatin loops, the long-range chromatin interactions that are mediated by protein factors and dynamically extruded by cohesin. We combined the use of FISH staining of a very short (33 kb) chromatin fragment, interferometric photoactivated localization microscopy (iPALM), and traveling salesman problem-based heuristic loop reconstruction algorithm from an image of the one of the strongest CTCF-mediated chromatin loops in human lymphoblastoid cells. In total, we have generated thirteen good quality images of the target chromatin region with 2–22 nm oligo probe localization precision. We visualized the shape of the single chromatin loops with unprecedented genomic resolution which allowed us to study the structural heterogeneity of chromatin looping. We were able to compare the physical distance maps from all reconstructed image-driven computational models with contact frequencies observed by ChIA-PET and Hi-C genomic-driven methods to examine the concordance between single cell imaging and population based genomic data.
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38
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Brown JM, De Ornellas S, Parisi E, Schermelleh L, Buckle VJ. RASER-FISH: non-denaturing fluorescence in situ hybridization for preservation of three-dimensional interphase chromatin structure. Nat Protoc 2022; 17:1306-1331. [PMID: 35379945 DOI: 10.1038/s41596-022-00685-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 01/10/2022] [Indexed: 11/09/2022]
Abstract
DNA fluorescence in situ hybridization (FISH) has been a central technique in advancing our understanding of how chromatin is organized within the nucleus. With the increasing resolution offered by super-resolution microscopy, the optimal maintenance of chromatin structure within the nucleus is essential for accuracy in measurements and interpretation of data. However, standard 3D-FISH requires potentially destructive heat denaturation in the presence of chaotropic agents such as formamide to allow access to the DNA strands for labeled FISH probes. To avoid the need to heat-denature, we developed Resolution After Single-strand Exonuclease Resection (RASER)-FISH, which uses exonuclease digestion to generate single-stranded target DNA for efficient probe binding over a 2 d process. Furthermore, RASER-FISH is easily combined with immunostaining of nuclear proteins or the detection of RNAs. Here, we provide detailed procedures for RASER-FISH in mammalian cultured cells to detect single loci, chromatin tracks and topologically associating domains with conventional and super-resolution 3D structured illumination microscopy. Moreover, we provide a validation and characterization of our method, demonstrating excellent preservation of chromatin structure and nuclear integrity, together with improved hybridization efficiency, compared with classic 3D-FISH protocols.
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Affiliation(s)
- Jill M Brown
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Oxford University, Oxford, UK
| | - Sara De Ornellas
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Oxford University, Oxford, UK
| | - Eva Parisi
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Oxford University, Oxford, UK
- School of Clinical Medicine, Addenbrooke's Hospital, Cambridge, UK
| | - Lothar Schermelleh
- Micron Oxford Advanced Bioimaging Unit, Department of Biochemistry, Oxford University, Oxford, UK
| | - Veronica J Buckle
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Oxford University, Oxford, UK.
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39
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Zhou K, Gebala M, Woods D, Sundararajan K, Edwards G, Krzizike D, Wereszczynski J, Straight AF, Luger K. CENP-N promotes the compaction of centromeric chromatin. Nat Struct Mol Biol 2022; 29:403-413. [PMID: 35422519 PMCID: PMC9010303 DOI: 10.1038/s41594-022-00758-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 03/08/2022] [Indexed: 12/14/2022]
Abstract
The histone variant CENP-A is the epigenetic determinant for the centromere, where it is interspersed with canonical H3 to form a specialized chromatin structure that nucleates the kinetochore. How nucleosomes at the centromere arrange into higher order structures is unknown. Here we demonstrate that the human CENP-A-interacting protein CENP-N promotes the stacking of CENP-A-containing mononucleosomes and nucleosomal arrays through a previously undefined interaction between the α6 helix of CENP-N with the DNA of a neighboring nucleosome. We describe the cryo-EM structures and biophysical characterization of such CENP-N-mediated nucleosome stacks and nucleosomal arrays and demonstrate that this interaction is responsible for the formation of densely packed chromatin at the centromere in the cell. Our results provide first evidence that CENP-A, together with CENP-N, promotes specific chromatin higher order structure at the centromere.
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Affiliation(s)
- Keda Zhou
- Department of Biochemistry, University of Colorado at Boulder, Boulder, CO, USA
| | - Magdalena Gebala
- Department of Biochemistry, Stanford University, Stanford, CA, USA
| | - Dustin Woods
- Department of Chemistry and the Center for Molecular Study of Condensed Soft Matter, Illinois Institute of Technology, Chicago, IL, USA
| | | | - Garrett Edwards
- Department of Biochemistry, University of Colorado at Boulder, Boulder, CO, USA
| | - Dan Krzizike
- Department of Biochemistry, University of Colorado at Boulder, Boulder, CO, USA
| | - Jeff Wereszczynski
- Department of Physics and the Center for Molecular Study of Condensed Soft Matter, Illinois Institute of Technology, Chicago, IL, USA
| | - Aaron F Straight
- Department of Biochemistry, Stanford University, Stanford, CA, USA.
| | - Karolin Luger
- Department of Biochemistry, University of Colorado at Boulder, Boulder, CO, USA.
- Howard Hughes Medical Institute, University of Colorado at Boulder, Boulder, CO, USA.
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40
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Delker RK, Munce RH, Hu M, Mann RS. Fluorescent labeling of genomic loci in Drosophila imaginal discs with heterologous DNA-binding proteins. CELL REPORTS METHODS 2022; 2:100175. [PMID: 35475221 PMCID: PMC9017127 DOI: 10.1016/j.crmeth.2022.100175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 11/02/2021] [Accepted: 02/11/2022] [Indexed: 11/25/2022]
Abstract
Using the Drosophila melanogaster Hox gene Ultrabithorax (Ubx) as an example, we demonstrate the use of three heterologous DNA-binding protein systems-LacI/LacO, ParB1/ParS1, and ParB2/ParS2-to label genomic loci in imaginal discs with the insertion of a small DNA tag. We compare each system, considering the impact of labeling in genomic regions (1) inside versus outside of a transcribed gene body and (2) with varying chromatin accessibility. We demonstrate the value of this system by interrogating the relationship between gene expression level and enhancer-promoter distance, as well as inter-allelic distance at the Ubx locus. We find that the distance between an essential intronic cis-regulatory element, anterobithorax (abx), and the promoter does not vary with expression level. In contrast, inter-allelic distance correlates with Ubx expression level.
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Affiliation(s)
- Rebecca K. Delker
- Department of Biochemistry and Molecular Biophysics, Columbia University Irving Medical Center, New York, NY, USA
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, USA
| | - Ross H. Munce
- Department of Biochemistry and Molecular Biophysics, Columbia University Irving Medical Center, New York, NY, USA
- Department of Genetics and Development, Columbia University Irving Medical Center, New York, NY, USA
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, USA
| | - Michelle Hu
- Department of Biochemistry and Molecular Biophysics, Columbia University Irving Medical Center, New York, NY, USA
| | - Richard S. Mann
- Department of Biochemistry and Molecular Biophysics, Columbia University Irving Medical Center, New York, NY, USA
- Department of Neuroscience, Columbia University Irving Medical Center, New York, NY, USA
- Department of Systems Biology, Columbia University Irving Medical Center, New York, NY, USA
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, USA
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41
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Yan J, Huangfu D. Epigenome rewiring in human pluripotent stem cells. Trends Cell Biol 2022; 32:259-271. [PMID: 34955367 PMCID: PMC8840982 DOI: 10.1016/j.tcb.2021.12.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 11/29/2021] [Accepted: 12/02/2021] [Indexed: 01/10/2023]
Abstract
The epigenome plays a crucial role in modulating the activity of regulatory elements, thereby orchestrating diverse transcriptional programs during embryonic development. Human (h)PSC stepwise differentiation provides an excellent platform for capturing dynamic epigenomic events during lineage transition in human development. Here we discuss how recent technological advances, from epigenomic mapping to targeted perturbation, are providing a more comprehensive appreciation of remodeling of the chromatin landscape during human development with implications for aberrant rewiring in disease. We predict that the continuous innovation of hPSC differentiation methods, epigenome mapping, and CRISPR (clustered regularly interspaced short palindromic repeats) perturbation technologies will allow researchers to build toward not only a comprehensive understanding of the epigenomic mechanisms governing development, but also a highly flexible way to model diseases with opportunities for translation.
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Affiliation(s)
- Jielin Yan
- Sloan Kettering Institute, 1275 York Avenue, New York, NY 10065, USA; Louis V. Gerstner Jr. Graduate School of Biomedical Sciences, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA
| | - Danwei Huangfu
- Sloan Kettering Institute, 1275 York Avenue, New York, NY 10065, USA.
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42
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Zibetti C. Deciphering the Retinal Epigenome during Development, Disease and Reprogramming: Advancements, Challenges and Perspectives. Cells 2022; 11:cells11050806. [PMID: 35269428 PMCID: PMC8908986 DOI: 10.3390/cells11050806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 02/15/2022] [Accepted: 02/18/2022] [Indexed: 02/01/2023] Open
Abstract
Retinal neurogenesis is driven by concerted actions of transcription factors, some of which are expressed in a continuum and across several cell subtypes throughout development. While seemingly redundant, many factors diversify their regulatory outcome on gene expression, by coordinating variations in chromatin landscapes to drive divergent retinal specification programs. Recent studies have furthered the understanding of the epigenetic contribution to the progression of age-related macular degeneration, a leading cause of blindness in the elderly. The knowledge of the epigenomic mechanisms that control the acquisition and stabilization of retinal cell fates and are evoked upon damage, holds the potential for the treatment of retinal degeneration. Herein, this review presents the state-of-the-art approaches to investigate the retinal epigenome during development, disease, and reprogramming. A pipeline is then reviewed to functionally interrogate the epigenetic and transcriptional networks underlying cell fate specification, relying on a truly unbiased screening of open chromatin states. The related work proposes an inferential model to identify gene regulatory networks, features the first footprinting analysis and the first tentative, systematic query of candidate pioneer factors in the retina ever conducted in any model organism, leading to the identification of previously uncharacterized master regulators of retinal cell identity, such as the nuclear factor I, NFI. This pipeline is virtually applicable to the study of genetic programs and candidate pioneer factors in any developmental context. Finally, challenges and limitations intrinsic to the current next-generation sequencing techniques are discussed, as well as recent advances in super-resolution imaging, enabling spatio-temporal resolution of the genome.
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Affiliation(s)
- Cristina Zibetti
- Department of Ophthalmology, Institute of Clinical Medicine, University of Oslo, Kirkeveien 166, Building 36, 0455 Oslo, Norway
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43
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Abstract
Lamins interact with a host of nuclear membrane proteins, transcription factors, chromatin regulators, signaling molecules, splicing factors, and even chromatin itself to form a nuclear subcompartment, the nuclear lamina, that is involved in a variety of cellular processes such as the governance of nuclear integrity, nuclear positioning, mitosis, DNA repair, DNA replication, splicing, signaling, mechanotransduction and -sensation, transcriptional regulation, and genome organization. Lamins are the primary scaffold for this nuclear subcompartment, but interactions with lamin-associated peptides in the inner nuclear membrane are self-reinforcing and mutually required. Lamins also interact, directly and indirectly, with peripheral heterochromatin domains called lamina-associated domains (LADs) and help to regulate dynamic 3D genome organization and expression of developmentally regulated genes.
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Affiliation(s)
- Xianrong Wong
- Laboratory of Developmental and Regenerative Biology, Skin Research Institute of Singapore, Agency for Science, Technology and Research (A∗STAR), Singapore 138648
| | - Ashley J Melendez-Perez
- Department of Biological Chemistry and Center for Epigenetics, Johns Hopkins University of Medicine, Baltimore, Maryland 21205, USA
| | - Karen L Reddy
- Department of Biological Chemistry and Center for Epigenetics, Johns Hopkins University of Medicine, Baltimore, Maryland 21205, USA
- Sidney Kimmel Cancer Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland 21231, USA
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44
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Downes DJ, Smith AL, Karpinska MA, Velychko T, Rue-Albrecht K, Sims D, Milne TA, Davies JOJ, Oudelaar AM, Hughes JR. Capture-C: a modular and flexible approach for high-resolution chromosome conformation capture. Nat Protoc 2022; 17:445-475. [PMID: 35121852 PMCID: PMC7613269 DOI: 10.1038/s41596-021-00651-w] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 10/27/2021] [Indexed: 12/16/2022]
Abstract
Chromosome conformation capture (3C) methods measure the spatial proximity between DNA elements in the cell nucleus. Many methods have been developed to sample 3C material, including the Capture-C family of protocols. Capture-C methods use oligonucleotides to enrich for interactions of interest from sequencing-ready 3C libraries. This approach is modular and has been adapted and optimized to work for sampling of disperse DNA elements (NuTi Capture-C), including from low cell inputs (LI Capture-C), as well as to generate Hi-C like maps for specific regions of interest (Tiled-C) and to interrogate multiway interactions (Tri-C). We present the design, experimental protocol and analysis pipeline for NuTi Capture-C in addition to the variations for generation of LI Capture-C, Tiled-C and Tri-C data. The entire procedure can be performed in 3 weeks and requires standard molecular biology skills and equipment, access to a next-generation sequencing platform, and basic bioinformatic skills. Implemented with other sequencing technologies, these methods can be used to identify regulatory interactions and to compare the structural organization of the genome in different cell types and genetic models.
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Affiliation(s)
- Damien J Downes
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Alastair L Smith
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
- MRC WIMM Centre for Computational Biology, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | | | - Taras Velychko
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Kevin Rue-Albrecht
- MRC WIMM Centre for Computational Biology, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - David Sims
- MRC WIMM Centre for Computational Biology, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Thomas A Milne
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
- NIHR Oxford Biomedical Research Centre, Haematology Theme, Oxford, UK
| | - James O J Davies
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | | | - Jim R Hughes
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK.
- MRC WIMM Centre for Computational Biology, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK.
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45
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Steindel M, Orsine de Almeida I, Strawbridge S, Chernova V, Holcman D, Ponjavic A, Basu S. Studying the Dynamics of Chromatin-Binding Proteins in Mammalian Cells Using Single-Molecule Localization Microscopy. Methods Mol Biol 2022; 2476:209-247. [PMID: 35635707 DOI: 10.1007/978-1-0716-2221-6_16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Single-molecule localization microscopy (SMLM) allows the super-resolved imaging of proteins within mammalian nuclei at spatial resolutions comparable to that of a nucleosome itself (~20 nm). The technique is therefore well suited to the study of chromatin structure. Fixed-cell SMLM has already allowed temporal "snapshots" of how proteins are arranged on chromatin within mammalian nuclei. In this chapter, we focus on how recent developments, for example in selective plane illumination, 3D SMLM, and protein labeling, have led to a range of live-cell SMLM studies. We describe how to carry out single-particle tracking (SPT) of single proteins and, by analyzing their diffusion parameters, how to determine whether proteins interact with chromatin, diffuse freely, or do both. We can study the numbers of proteins that interact with chromatin and also determine their residence time on chromatin. We can determine whether these proteins form functional clusters within the nucleus as well as whether they form specific nuclear structures.
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Affiliation(s)
- Maike Steindel
- Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK
| | | | - Stanley Strawbridge
- Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK
| | - Valentyna Chernova
- Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK
| | - David Holcman
- Group of Computational Biology and Applied Mathematics, Institute of Biology, Ecole Normale Supérieure, Paris, France
| | - Aleks Ponjavic
- School of Physics and Astronomy and School of Food Science and Nutrition, University of Leeds, Leeds, UK.
| | - Srinjan Basu
- Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK.
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46
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Lochs SJA, Kind J. Simultaneous Quantification of Spatial Genome Positioning and Transcriptomics in Single Cells with scDam&T-Seq. Methods Mol Biol 2022; 2532:215-241. [PMID: 35867252 DOI: 10.1007/978-1-0716-2497-5_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Spatial genome organization is considered to play an important role in mammalian cells, by guiding gene expression programs and supporting lineage specification. Yet it is still an outstanding question in the field what the direct impact of spatial genome organization on gene expression is. To elucidate this relationship further, we have recently developed scDam&T-seq, a method that simultaneously quantifies protein-DNA interactions and transcriptomes in single cells. This method efficiently combines two preexisting methods: DamID for measuring protein-DNA contacts and CEL-Seq2 for quantification of the transcriptome in single cells. scDam&T-seq has been successfully applied to measure DNA contacts with the nuclear lamina, while at the same time revealing the effect of these contacts on gene expression. This method is applicable to many different proteins of interest and can thereby aid in studying the relationship between protein-DNA interactions and gene expression in single cells.
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Affiliation(s)
- Silke J A Lochs
- Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences (KNAW), University Medical Center Utrecht, Radboud University & Oncode Institute, Utrecht, The Netherlands
| | - Jop Kind
- Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences (KNAW), University Medical Center Utrecht, Radboud University & Oncode Institute, Utrecht, The Netherlands.
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47
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Sabaté T, Zimmer C, Bertrand E. Versatile CRISPR-Based Method for Site-Specific Insertion of Repeat Arrays to Visualize Chromatin Loci in Living Cells. Methods Mol Biol 2022; 2532:275-290. [PMID: 35867254 DOI: 10.1007/978-1-0716-2497-5_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Hi-C and related sequencing-based techniques have brought a detailed understanding of the 3D genome architecture and the discovery of novel structures such as topologically associating domains (TADs) and chromatin loops, which emerge from cohesin-mediated DNA extrusion. However, these techniques require cell fixation, which precludes assessment of chromatin structure dynamics, and are generally restricted to population averages, thus masking cell-to-cell heterogeneity. By contrast, live-cell imaging allows to characterize and quantify the temporal dynamics of chromatin, potentially including TADs and loops in single cells. Specific chromatin loci can be visualized at high temporal and spatial resolution by inserting a repeat array from bacterial operator sequences bound by fluorescent tags. Using two different types of repeats allows to tag both anchors of a loop in different colors, thus enabling to track them separately even when they are in close vicinity. Here, we describe a versatile cloning method for generating many repeat array repair cassettes in parallel and inserting them by CRISPR-Cas9 into the human genome. This method should be instrumental to studying chromatin loop dynamics in single human cells.
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Affiliation(s)
- Thomas Sabaté
- Imaging and Modeling Unit, Institut Pasteur, UMR 3691 CNRS, IP CNRS, Paris, France.
- IGH, University of Montpellier, CNRS, Montpellier, France.
- Sorbonne Université, Collège Doctoral, Paris, France.
| | - Christophe Zimmer
- Imaging and Modeling Unit, Institut Pasteur, UMR 3691 CNRS, IP CNRS, Paris, France
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48
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Kumar S, Kaur S, Seem K, Kumar S, Mohapatra T. Understanding 3D Genome Organization and Its Effect on Transcriptional Gene Regulation Under Environmental Stress in Plant: A Chromatin Perspective. Front Cell Dev Biol 2021; 9:774719. [PMID: 34957106 PMCID: PMC8692796 DOI: 10.3389/fcell.2021.774719] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Accepted: 11/23/2021] [Indexed: 01/17/2023] Open
Abstract
The genome of a eukaryotic organism is comprised of a supra-molecular complex of chromatin fibers and intricately folded three-dimensional (3D) structures. Chromosomal interactions and topological changes in response to the developmental and/or environmental stimuli affect gene expression. Chromatin architecture plays important roles in DNA replication, gene expression, and genome integrity. Higher-order chromatin organizations like chromosome territories (CTs), A/B compartments, topologically associating domains (TADs), and chromatin loops vary among cells, tissues, and species depending on the developmental stage and/or environmental conditions (4D genomics). Every chromosome occupies a separate territory in the interphase nucleus and forms the top layer of hierarchical structure (CTs) in most of the eukaryotes. While the A and B compartments are associated with active (euchromatic) and inactive (heterochromatic) chromatin, respectively, having well-defined genomic/epigenomic features, TADs are the structural units of chromatin. Chromatin architecture like TADs as well as the local interactions between promoter and regulatory elements correlates with the chromatin activity, which alters during environmental stresses due to relocalization of the architectural proteins. Moreover, chromatin looping brings the gene and regulatory elements in close proximity for interactions. The intricate relationship between nucleotide sequence and chromatin architecture requires a more comprehensive understanding to unravel the genome organization and genetic plasticity. During the last decade, advances in chromatin conformation capture techniques for unravelling 3D genome organizations have improved our understanding of genome biology. However, the recent advances, such as Hi-C and ChIA-PET, have substantially increased the resolution, throughput as well our interest in analysing genome organizations. The present review provides an overview of the historical and contemporary perspectives of chromosome conformation capture technologies, their applications in functional genomics, and the constraints in predicting 3D genome organization. We also discuss the future perspectives of understanding high-order chromatin organizations in deciphering transcriptional regulation of gene expression under environmental stress (4D genomics). These might help design the climate-smart crop to meet the ever-growing demands of food, feed, and fodder.
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Affiliation(s)
- Suresh Kumar
- Division of Biochemistry, ICAR-Indian Agricultural Research Institute, New Delhi, India
| | - Simardeep Kaur
- Division of Biochemistry, ICAR-Indian Agricultural Research Institute, New Delhi, India
| | - Karishma Seem
- Division of Biochemistry, ICAR-Indian Agricultural Research Institute, New Delhi, India
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49
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Kanapeckaitė A, Burokienė N, Mažeikienė A, Cottrell GS, Widera D. Biophysics is reshaping our perception of the epigenome: from DNA-level to high-throughput studies. BIOPHYSICAL REPORTS 2021; 1:100028. [PMID: 36425454 PMCID: PMC9680810 DOI: 10.1016/j.bpr.2021.100028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 09/24/2021] [Indexed: 06/16/2023]
Abstract
Epigenetic research holds great promise to advance our understanding of biomarkers and regulatory processes in health and disease. An increasing number of new approaches, ranging from molecular to biophysical analyses, enable identifying epigenetic changes on the level of a single gene or the whole epigenome. The aim of this review is to highlight how the field is shifting from completely molecular-biology-driven solutions to multidisciplinary strategies including more reliance on biophysical analysis tools. Biophysics not only offers technical advancements in imaging or structure analysis but also helps to explore regulatory interactions. New computational methods are also being developed to meet the demand of growing data volumes and their processing. Therefore, it is important to capture these new directions in epigenetics from a biophysical perspective and discuss current challenges as well as multiple applications of biophysical methods and tools. Specifically, we gradually introduce different biophysical research methods by first considering the DNA-level information and eventually higher-order chromatin structures. Moreover, we aim to highlight that the incorporation of bioinformatics, machine learning, and artificial intelligence into biophysical analysis allows gaining new insights into complex epigenetic processes. The gained understanding has already proven useful in translational and clinical research providing better patient stratification options or new therapeutic insights. Together, this offers a better readiness to transform bench-top experiments into industrial high-throughput applications with a possibility to employ developed methods in clinical practice and diagnostics.
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Affiliation(s)
- Austė Kanapeckaitė
- Algorithm379, Laisvės g. 7, LT 12007, Vilnius, Lithuania
- Reading School of Pharmacy, Whiteknights, Reading, UK, RG6 6UB
| | - Neringa Burokienė
- Clinics of Internal Diseases, Family Medicine and Oncology, Institute of Clinical Medicine, Faculty of Medicine, Vilnius University, M. K. Čiurlionio str. 21/27, LT-03101 Vilnius, Lithuania
| | - Asta Mažeikienė
- Department of Physiology, Biochemistry, Microbiology and Laboratory Medicine, Institute of Biomedical Sciences, Faculty of Medicine, M. K. Čiurlionio str. 21/27, LT-03101 Vilnius, Lithuania
| | | | - Darius Widera
- Reading School of Pharmacy, Whiteknights, Reading, UK, RG6 6UB
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50
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Cardozo Gizzi AM. A Shift in Paradigms: Spatial Genomics Approaches to Reveal Single-Cell Principles of Genome Organization. Front Genet 2021; 12:780822. [PMID: 34868269 PMCID: PMC8640135 DOI: 10.3389/fgene.2021.780822] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 11/03/2021] [Indexed: 12/12/2022] Open
Abstract
The genome tridimensional (3D) organization and its role towards the regulation of key cell processes such as transcription is currently a main question in biology. Interphase chromosomes are spatially segregated into "territories," epigenetically-defined large domains of chromatin that interact to form "compartments" with common transcriptional status, and insulator-flanked domains called "topologically associating domains" (TADs). Moreover, chromatin organizes around nuclear structures such as lamina, speckles, or the nucleolus to acquire a higher-order genome organization. Due to recent technological advances, the different hierarchies are being solved. Particularly, advances in microscopy technologies are shedding light on the genome structure at multiple levels. Intriguingly, more and more reports point to high variability and stochasticity at the single-cell level. However, the functional consequences of such variability in genome conformation are still unsolved. Here, I will discuss the implication of the cell-to-cell heterogeneity at the different scales in the context of newly developed imaging approaches, particularly multiplexed Fluorescence in situ hybridization methods that enabled "chromatin tracing." Extensions of these methods are now combining spatial information of dozens to thousands of genomic loci with the localization of nuclear features such as the nucleolus, nuclear speckles, or even histone modifications, creating the fast-moving field of "spatial genomics." As our view of genome organization shifts the focus from ensemble to single-cell, new insights to fundamental questions begin to emerge.
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Affiliation(s)
- Andres M Cardozo Gizzi
- Centro de Investigación en Medicina Traslacional Severo Amuchastegui (CIMETSA), Instituto Universitario de Ciencias Biomédicas de Córdoba (IUCBC), CONICET, Córdoba, Argentina
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