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Murtaza G, Butaney B, Wagner J, Singh R. scGrapHiC: deep learning-based graph deconvolution for Hi-C using single cell gene expression. Bioinformatics 2024; 40:i490-i500. [PMID: 38940151 PMCID: PMC11256916 DOI: 10.1093/bioinformatics/btae223] [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] [Indexed: 06/29/2024] Open
Abstract
SUMMARY Single-cell Hi-C (scHi-C) protocol helps identify cell-type-specific chromatin interactions and sheds light on cell differentiation and disease progression. Despite providing crucial insights, scHi-C data is often underutilized due to the high cost and the complexity of the experimental protocol. We present a deep learning framework, scGrapHiC, that predicts pseudo-bulk scHi-C contact maps using pseudo-bulk scRNA-seq data. Specifically, scGrapHiC performs graph deconvolution to extract genome-wide single-cell interactions from a bulk Hi-C contact map using scRNA-seq as a guiding signal. Our evaluations show that scGrapHiC, trained on seven cell-type co-assay datasets, outperforms typical sequence encoder approaches. For example, scGrapHiC achieves a substantial improvement of 23.2% in recovering cell-type-specific Topologically Associating Domains over the baselines. It also generalizes to unseen embryo and brain tissue samples. scGrapHiC is a novel method to generate cell-type-specific scHi-C contact maps using widely available genomic signals that enables the study of cell-type-specific chromatin interactions. AVAILABILITY AND IMPLEMENTATION The GitHub link: https://github.com/rsinghlab/scGrapHiC contains the source code of scGrapHiC and associated scripts to preprocess publicly available datasets to produce the results and visualizations we have discuss in this manuscript.
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Affiliation(s)
- Ghulam Murtaza
- Department of Computer Science, Brown University, 115 Waterman Street, Providence, RI, 02912, United States
| | - Byron Butaney
- Department of Computer Science, Brown University, 115 Waterman Street, Providence, RI, 02912, United States
| | - Justin Wagner
- Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, 20899, United States
| | - Ritambhara Singh
- Department of Computer Science, Brown University, 115 Waterman Street, Providence, RI, 02912, United States
- Center for Computational Molecular Biology, Brown University, 164 Angell Street, Providence, RI, 02912, United States
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2
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Chavan A, Isenhart R, Nguyen SC, Kotb NM, Harke J, Sintsova A, Ulukaya G, Uliana F, Ashiono C, Kutay U, Pegoraro G, Rangan P, Joyce EF, Jagannathan M. A nuclear architecture screen in Drosophila identifies Stonewall as a link between chromatin position at the nuclear periphery and germline stem cell fate. Genes Dev 2024; 38:415-435. [PMID: 38866555 PMCID: PMC11216176 DOI: 10.1101/gad.351424.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2023] [Accepted: 05/21/2024] [Indexed: 06/14/2024]
Abstract
The association of genomic loci to the nuclear periphery is proposed to facilitate cell type-specific gene repression and influence cell fate decisions. However, the interplay between gene position and expression remains incompletely understood, in part because the proteins that position genomic loci at the nuclear periphery remain unidentified. Here, we used an Oligopaint-based HiDRO screen targeting ∼1000 genes to discover novel regulators of nuclear architecture in Drosophila cells. We identified the heterochromatin-associated protein Stonewall (Stwl) as a factor promoting perinuclear chromatin positioning. In female germline stem cells (GSCs), Stwl binds and positions chromatin loci, including GSC differentiation genes, at the nuclear periphery. Strikingly, Stwl-dependent perinuclear positioning is associated with transcriptional repression, highlighting a likely mechanism for Stwl's known role in GSC maintenance and ovary homeostasis. Thus, our study identifies perinuclear anchors in Drosophila and demonstrates the importance of gene repression at the nuclear periphery for cell fate.
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Affiliation(s)
- Ankita Chavan
- Institute of Biochemistry, Department of Biology, Eidgenössische Technische Hochschule (ETH) Zürich, Zürich 8093, Switzerland
- Bringing Materials to Life Consortium, ETH Zürich, Zürich 8093, Switzerland
- Life Science Zürich Graduate School, Zürich 8057, Switzerland
| | - Randi Isenhart
- Penn Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Son C Nguyen
- Penn Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Noor M Kotb
- Department of Cell, Developmental, and Regenerative Biology, Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - Jailynn Harke
- Penn Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Anna Sintsova
- Institute of Microbiology, Department of Biology, ETH Zürich, Zürich 8093, Switzerland
| | - Gulay Ulukaya
- Bioinformatics for Next-Generation Sequencing (BiNGS) Core, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - Federico Uliana
- Institute of Biochemistry, Department of Biology, Eidgenössische Technische Hochschule (ETH) Zürich, Zürich 8093, Switzerland
| | - Caroline Ashiono
- Institute of Biochemistry, Department of Biology, Eidgenössische Technische Hochschule (ETH) Zürich, Zürich 8093, Switzerland
| | - Ulrike Kutay
- Institute of Biochemistry, Department of Biology, Eidgenössische Technische Hochschule (ETH) Zürich, Zürich 8093, Switzerland
| | - Gianluca Pegoraro
- High-Throughput Imaging Facility (HiTIF), National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Prashanth Rangan
- Department of Cell, Developmental, and Regenerative Biology, Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - Eric F Joyce
- Penn Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA;
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Madhav Jagannathan
- Institute of Biochemistry, Department of Biology, Eidgenössische Technische Hochschule (ETH) Zürich, Zürich 8093, Switzerland;
- Bringing Materials to Life Consortium, ETH Zürich, Zürich 8093, Switzerland
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3
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Taylor A, Prasad A, Mueller RL. Amphibian Segmentation Clock Models Suggest How Large Genome and Cell Sizes Slow Developmental Rate. Integr Org Biol 2024; 6:obae021. [PMID: 39006893 PMCID: PMC11245677 DOI: 10.1093/iob/obae021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Revised: 05/20/2024] [Accepted: 06/18/2024] [Indexed: 07/16/2024] Open
Abstract
Evolutionary increases in genome size, cell volume, and nuclear volume have been observed across the tree of life, with positive correlations documented between all three traits. Developmental tempo slows as genomes, nuclei, and cells increase in size, yet the driving mechanisms are poorly understood. To bridge this gap, we use a mathematical model of the somitogenesis clock to link slowed developmental tempo with changes in intra-cellular gene expression kinetics induced by increasing genome size and nuclear volume. We adapt a well-known somitogenesis clock model to two model amphibian species that vary 10-fold in genome size: Xenopus laevis (3.1 Gb) and Ambystoma mexicanum (32 Gb). Based on simulations and backed by analytical derivations, we identify parameter changes originating from increased genome and nuclear size that slow gene expression kinetics. We simulate biological scenarios for which these parameter changes mathematically recapitulate slowed gene expression in A. mexicanum relative to X. laevis, and we consider scenarios for which additional alterations in gene product stability and chromatin packing are necessary. Results suggest that slowed degradation rates as well as changes induced by increasing nuclear volume and intron length, which remain relatively unexplored, are significant drivers of slowed developmental tempo.
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Affiliation(s)
- A Taylor
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - A Prasad
- Department of Chemical and Biological Engineering, Colorado State University, Fort Collins, CO 80523, USA
| | - R Lockridge Mueller
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA
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4
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Han X, Xing L, Hong Y, Zhang X, Hao B, Lu JY, Huang M, Wang Z, Ma S, Zhan G, Li T, Hao X, Tao Y, Li G, Zhou S, Zheng Z, Shao W, Zeng Y, Ma D, Zhang W, Xie Z, Deng H, Yan J, Deng W, Shen X. Nuclear RNA homeostasis promotes systems-level coordination of cell fate and senescence. Cell Stem Cell 2024; 31:694-716.e11. [PMID: 38631356 DOI: 10.1016/j.stem.2024.03.015] [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: 09/22/2023] [Revised: 02/01/2024] [Accepted: 03/26/2024] [Indexed: 04/19/2024]
Abstract
Understanding cellular coordination remains a challenge despite knowledge of individual pathways. The RNA exosome, targeting a wide range of RNA substrates, is often downregulated in cellular senescence. Utilizing an auxin-inducible system, we observed that RNA exosome depletion in embryonic stem cells significantly affects the transcriptome and proteome, causing pluripotency loss and pre-senescence onset. Mechanistically, exosome depletion triggers acute nuclear RNA aggregation, disrupting nuclear RNA-protein equilibrium. This disturbance limits nuclear protein availability and hinders polymerase initiation and engagement, reducing gene transcription. Concurrently, it promptly disrupts nucleolar transcription, ribosomal processes, and nuclear exporting, resulting in a translational shutdown. Prolonged exosome depletion induces nuclear structural changes resembling senescent cells, including aberrant chromatin compaction, chromocenter disassembly, and intensified heterochromatic foci. These effects suggest that the dynamic turnover of nuclear RNA orchestrates crosstalk between essential processes to optimize cellular function. Disruptions in nuclear RNA homeostasis result in systemic functional decline, altering the cell state and promoting senescence.
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Affiliation(s)
- Xue Han
- State Key Laboratory of Membrane Biology, Beijing Frontier Research Center for Biological Structure, Tsinghua-Peking Joint Center for Life Sciences, School of Basic Medical Sciences, Tsinghua University, Beijing 100084, China
| | - Linqing Xing
- State Key Laboratory of Membrane Biology, Beijing Frontier Research Center for Biological Structure, Tsinghua-Peking Joint Center for Life Sciences, School of Basic Medical Sciences, Tsinghua University, Beijing 100084, China
| | - Yantao Hong
- State Key Laboratory of Membrane Biology, Beijing Frontier Research Center for Biological Structure, Tsinghua-Peking Joint Center for Life Sciences, School of Basic Medical Sciences, Tsinghua University, Beijing 100084, China
| | - Xuechun Zhang
- State Key Laboratory of Membrane Biology, Beijing Frontier Research Center for Biological Structure, Tsinghua-Peking Joint Center for Life Sciences, School of Basic Medical Sciences, Tsinghua University, Beijing 100084, China
| | - Bo Hao
- SXMU-Tsinghua Collaborative Innovation Center for Frontier Medicine, Shanxi Medical University, Taiyuan, Shanxi 030001, China
| | - J Yuyang Lu
- State Key Laboratory of Membrane Biology, Beijing Frontier Research Center for Biological Structure, Tsinghua-Peking Joint Center for Life Sciences, School of Basic Medical Sciences, Tsinghua University, Beijing 100084, China
| | - Mengyuan Huang
- State Key Laboratory of Membrane Biology, Beijing Frontier Research Center for Biological Structure, Tsinghua-Peking Joint Center for Life Sciences, School of Basic Medical Sciences, Tsinghua University, Beijing 100084, China
| | - Zuhui Wang
- Biomedical Pioneering Innovation Center (BIOPIC), Beijing Advanced Innovation Center for Genomics (ICG), Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
| | - Shaoqian Ma
- State Key Laboratory of Membrane Biology, Beijing Frontier Research Center for Biological Structure, Tsinghua-Peking Joint Center for Life Sciences, School of Basic Medical Sciences, Tsinghua University, Beijing 100084, China
| | - Ge Zhan
- State Key Laboratory of Membrane Biology, Beijing Frontier Research Center for Biological Structure, Tsinghua-Peking Joint Center for Life Sciences, School of Basic Medical Sciences, Tsinghua University, Beijing 100084, China
| | - Tong Li
- State Key Laboratory of Membrane Biology, Beijing Frontier Research Center for Biological Structure, Tsinghua-Peking Joint Center for Life Sciences, School of Basic Medical Sciences, Tsinghua University, Beijing 100084, China
| | - Xiaowen Hao
- State Key Laboratory of Membrane Biology, Beijing Frontier Research Center for Biological Structure, Tsinghua-Peking Joint Center for Life Sciences, School of Basic Medical Sciences, Tsinghua University, Beijing 100084, China
| | - Yibing Tao
- State Key Laboratory of Membrane Biology, Beijing Frontier Research Center for Biological Structure, Tsinghua-Peking Joint Center for Life Sciences, School of Basic Medical Sciences, Tsinghua University, Beijing 100084, China
| | - Guanwen Li
- State Key Laboratory of Membrane Biology, Beijing Frontier Research Center for Biological Structure, Tsinghua-Peking Joint Center for Life Sciences, School of Basic Medical Sciences, Tsinghua University, Beijing 100084, China
| | - Shuqin Zhou
- State Key Laboratory of Membrane Biology, Beijing Frontier Research Center for Biological Structure, Tsinghua-Peking Joint Center for Life Sciences, School of Basic Medical Sciences, Tsinghua University, Beijing 100084, China
| | - Zheng Zheng
- State Key Laboratory of Membrane Biology, Beijing Frontier Research Center for Biological Structure, Tsinghua-Peking Joint Center for Life Sciences, School of Basic Medical Sciences, Tsinghua University, Beijing 100084, China
| | - Wen Shao
- State Key Laboratory of Membrane Biology, Beijing Frontier Research Center for Biological Structure, Tsinghua-Peking Joint Center for Life Sciences, School of Basic Medical Sciences, Tsinghua University, Beijing 100084, China
| | - Yitian Zeng
- State Key Laboratory of Membrane Biology, Beijing Frontier Research Center for Biological Structure, Tsinghua-Peking Joint Center for Life Sciences, School of Basic Medical Sciences, Tsinghua University, Beijing 100084, China
| | - Dacheng Ma
- MOE Key Laboratory of Bioinformatics and Bioinformatics Division, Center for Synthetic and Systems Biology, Department of Automation, Beijing National Research Center for Information Science and Technology, Tsinghua University, Beijing 100084, China
| | - Wenhao Zhang
- MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Zhen Xie
- MOE Key Laboratory of Bioinformatics and Bioinformatics Division, Center for Synthetic and Systems Biology, Department of Automation, Beijing National Research Center for Information Science and Technology, Tsinghua University, Beijing 100084, China
| | - Haiteng Deng
- MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Jiangwei Yan
- SXMU-Tsinghua Collaborative Innovation Center for Frontier Medicine, Shanxi Medical University, Taiyuan, Shanxi 030001, China
| | - Wulan Deng
- Biomedical Pioneering Innovation Center (BIOPIC), Beijing Advanced Innovation Center for Genomics (ICG), Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
| | - Xiaohua Shen
- State Key Laboratory of Membrane Biology, Beijing Frontier Research Center for Biological Structure, Tsinghua-Peking Joint Center for Life Sciences, School of Basic Medical Sciences, Tsinghua University, Beijing 100084, China; SXMU-Tsinghua Collaborative Innovation Center for Frontier Medicine, Shanxi Medical University, Taiyuan, Shanxi 030001, China.
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5
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Cai P, Casas CJ, Plancarte GQ, Mikawa T, Hua LL. Ipsilateral restriction of chromosome movement along a centrosome, and apical-basal axis during the cell cycle. RESEARCH SQUARE 2024:rs.3.rs-4283973. [PMID: 38746098 PMCID: PMC11092853 DOI: 10.21203/rs.3.rs-4283973/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
Little is known about how distance between homologous chromosomes are controlled during the cell cycle. Here, we show that the distribution of centromere components display two discrete clusters placed to either side of the centrosome and apical/basal axis from prophase to G1 interphase. 4-Dimensional live cell imaging analysis of centromere and centrosome tracking reveals that centromeres oscillate largely within one cluster, but do not cross over to the other cluster. We propose a model of an axis-dependent ipsilateral restriction of chromosome oscillations throughout mitosis.
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6
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Keller D, Stinus S, Umlauf D, Gourbeyre E, Biot E, Olivier N, Mahou P, Beaurepaire E, Andrey P, Crabbe L. Non-random spatial organization of telomeres varies during the cell cycle and requires LAP2 and BAF. iScience 2024; 27:109343. [PMID: 38510147 PMCID: PMC10951912 DOI: 10.1016/j.isci.2024.109343] [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: 08/22/2023] [Revised: 11/30/2023] [Accepted: 02/22/2024] [Indexed: 03/22/2024] Open
Abstract
Spatial genome organization within the nucleus influences major biological processes and is impacted by the configuration of linear chromosomes. Here, we applied 3D spatial statistics and modeling on high-resolution telomere and centromere 3D-structured illumination microscopy images in cancer cells. We found a multi-scale organization of telomeres that dynamically evolved from a mixed clustered-and-regular distribution in early G1 to a purely regular distribution as cells progressed through the cell cycle. In parallel, our analysis revealed two pools of peripheral and internal telomeres, the proportions of which were inverted during the cell cycle. We then conducted a targeted screen using MadID to identify the molecular pathways driving or maintaining telomere anchoring to the nuclear envelope observed in early G1. Lamina-associated polypeptide (LAP) proteins were found transiently localized to telomeres in anaphase, a stage where LAP2α initiates the reformation of the nuclear envelope, and impacted telomere redistribution in the next interphase together with their partner barrier-to-autointegration factor (BAF).
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Affiliation(s)
- Debora Keller
- Molecular, Cellular and Developmental Biology Department (MCD), Centre de Biologie Intégrative (CBI), University of Toulouse, CNRS, UPS, 31062 Toulouse, France
- Laboratory for Optics and Biosciences, École polytechnique, CNRS, INSERM, IP Paris, 91128 Palaiseau, France
| | - Sonia Stinus
- Molecular, Cellular and Developmental Biology Department (MCD), Centre de Biologie Intégrative (CBI), University of Toulouse, CNRS, UPS, 31062 Toulouse, France
| | - David Umlauf
- Molecular, Cellular and Developmental Biology Department (MCD), Centre de Biologie Intégrative (CBI), University of Toulouse, CNRS, UPS, 31062 Toulouse, France
| | - Edith Gourbeyre
- Molecular, Cellular and Developmental Biology Department (MCD), Centre de Biologie Intégrative (CBI), University of Toulouse, CNRS, UPS, 31062 Toulouse, France
| | - Eric Biot
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France
| | - Nicolas Olivier
- Laboratory for Optics and Biosciences, École polytechnique, CNRS, INSERM, IP Paris, 91128 Palaiseau, France
| | - Pierre Mahou
- Laboratory for Optics and Biosciences, École polytechnique, CNRS, INSERM, IP Paris, 91128 Palaiseau, France
| | - Emmanuel Beaurepaire
- Laboratory for Optics and Biosciences, École polytechnique, CNRS, INSERM, IP Paris, 91128 Palaiseau, France
| | - Philippe Andrey
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France
| | - Laure Crabbe
- Molecular, Cellular and Developmental Biology Department (MCD), Centre de Biologie Intégrative (CBI), University of Toulouse, CNRS, UPS, 31062 Toulouse, France
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7
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Toh H, Sasaki H. Spatiotemporal DNA methylation dynamics shape megabase-scale methylome landscapes. Life Sci Alliance 2024; 7:e202302403. [PMID: 38233073 PMCID: PMC10794778 DOI: 10.26508/lsa.202302403] [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: 09/28/2023] [Revised: 01/06/2024] [Accepted: 01/08/2024] [Indexed: 01/19/2024] Open
Abstract
DNA methylation is an essential epigenetic mechanism that regulates cellular reprogramming and development. Studies using whole-genome bisulfite sequencing have revealed distinct DNA methylome landscapes in human and mouse cells and tissues. However, the factors responsible for the differences in megabase-scale methylome patterns between cell types remain poorly understood. By analyzing publicly available 258 human and 301 mouse whole-genome bisulfite sequencing datasets, we reveal that genomic regions rich in guanine and cytosine, when located near the nuclear center, are highly susceptible to both global DNA demethylation and methylation events during embryonic and germline reprogramming. Furthermore, we found that regions that generate partially methylated domains during global DNA methylation are more likely to resist global DNA demethylation, contain high levels of adenine and thymine, and are adjacent to the nuclear lamina. The spatial properties of genomic regions, influenced by their guanine-cytosine content, are likely to affect the accessibility of molecules involved in DNA (de)methylation. These properties shape megabase-scale DNA methylation patterns and change as cells differentiate, leading to the emergence of different megabase-scale methylome patterns across cell types.
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Affiliation(s)
- Hidehiro Toh
- https://ror.org/02xg1m795 Advanced Genomics Center, National Institute of Genetics, Mishima, Japan
- https://ror.org/00p4k0j84 Division of Epigenomics and Development, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
| | - Hiroyuki Sasaki
- https://ror.org/00p4k0j84 Division of Epigenomics and Development, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
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8
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Cai P, Casas CJ, Plancarte GQ, Hua LL, Mikawa T. Ipsilateral restriction of chromosome movement along a centrosome, and apical-basal axis during the cell cycle. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.03.27.534352. [PMID: 37034601 PMCID: PMC10081237 DOI: 10.1101/2023.03.27.534352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Little is known about how distance between homologous chromosomes are controlled during the cell cycle. Here, we show that the distribution of centromere components display two discrete clusters placed to either side of the centrosome and apical/basal axis from prophase to G 1 interphase. 4-Dimensional live cell imaging analysis of centromere and centrosome tracking reveals that centromeres oscillate largely within one cluster, but do not cross over to the other cluster. We propose a model of an axis-dependent ipsilateral restriction of chromosome oscillations throughout mitosis.
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9
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Schmidt A, Zhang H, Schmitt S, Rausch C, Popp O, Chen J, Cmarko D, Butter F, Dittmar G, Lermyte F, Cardoso MC. The Proteomic Composition and Organization of Constitutive Heterochromatin in Mouse Tissues. Cells 2024; 13:139. [PMID: 38247831 PMCID: PMC10814525 DOI: 10.3390/cells13020139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 12/13/2023] [Accepted: 01/09/2024] [Indexed: 01/23/2024] Open
Abstract
Pericentric heterochromatin (PCH) forms spatio-temporarily distinct compartments and affects chromosome organization and stability. Albeit some of its components are known, an elucidation of its proteome and how it differs between tissues in vivo is lacking. Here, we find that PCH compartments are dynamically organized in a tissue-specific manner, possibly reflecting compositional differences. As the mouse brain and liver exhibit very different PCH architecture, we isolated native PCH fractions from these tissues, analyzed their protein compositions using quantitative mass spectrometry, and compared them to identify common and tissue-specific PCH proteins. In addition to heterochromatin-enriched proteins, the PCH proteome includes RNA/transcription and membrane-related proteins, which showed lower abundance than PCH-enriched proteins. Thus, we applied a cut-off of PCH-unspecific candidates based on their abundance and validated PCH-enriched proteins. Amongst the hits, MeCP2 was classified into brain PCH-enriched proteins, while linker histone H1 was not. We found that H1 and MeCP2 compete to bind to PCH and regulate PCH organization in opposite ways. Altogether, our workflow of unbiased PCH isolation, quantitative mass spectrometry, and validation-based analysis allowed the identification of proteins that are common and tissue-specifically enriched at PCH. Further investigation of selected hits revealed their opposing role in heterochromatin higher-order architecture in vivo.
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Affiliation(s)
- Annika Schmidt
- Cell Biology and Epigenetics, Department of Biology, Technical University of Darmstadt, 64287 Darmstadt, Germany (S.S.)
| | - Hui Zhang
- Cell Biology and Epigenetics, Department of Biology, Technical University of Darmstadt, 64287 Darmstadt, Germany (S.S.)
| | - Stephanie Schmitt
- Cell Biology and Epigenetics, Department of Biology, Technical University of Darmstadt, 64287 Darmstadt, Germany (S.S.)
| | - Cathia Rausch
- Cell Biology and Epigenetics, Department of Biology, Technical University of Darmstadt, 64287 Darmstadt, Germany (S.S.)
| | - Oliver Popp
- Proteomics Platform, Max-Delbrueck-Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany
| | - Jiaxuan Chen
- Institute of Molecular Biology (IMB), 55128 Mainz, Germany
| | - Dusan Cmarko
- Institute of Biology and Medical Genetics, First Faculty of Medicine, Charles University and General University Hospital in Prague, 128 00 Prague, Czech Republic
| | - Falk Butter
- Institute of Molecular Biology (IMB), 55128 Mainz, Germany
| | - Gunnar Dittmar
- Proteomics Platform, Max-Delbrueck-Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany
| | - Frederik Lermyte
- Clemens-Schöpf Institute of Organic Chemistry and Biochemistry, Department of Chemistry, Technical University of Darmstadt, 64287 Darmstadt, Germany
| | - M. Cristina Cardoso
- Cell Biology and Epigenetics, Department of Biology, Technical University of Darmstadt, 64287 Darmstadt, Germany (S.S.)
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10
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van Bueren MAE, Janssen A. The impact of chromatin on double-strand break repair: Imaging tools and discoveries. DNA Repair (Amst) 2024; 133:103592. [PMID: 37976899 DOI: 10.1016/j.dnarep.2023.103592] [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: 07/27/2023] [Revised: 10/16/2023] [Accepted: 11/07/2023] [Indexed: 11/19/2023]
Abstract
Eukaryotic nuclei are constantly being exposed to factors that break or chemically modify the DNA. Accurate repair of this DNA damage is crucial to prevent DNA mutations and maintain optimal cell function. To overcome the detrimental effects of DNA damage, a multitude of repair pathways has evolved. These pathways need to function properly within the different chromatin domains present in the nucleus. Each of these domains exhibit distinct molecular- and bio-physical characteristics that can influence the response to DNA damage. In particular, chromatin domains highly enriched for repetitive DNA sequences, such as nucleoli, centromeres and pericentromeric heterochromatin require tailored repair mechanisms to safeguard genome stability. Work from the past decades has led to the development of innovative imaging tools as well as inducible DNA damage techniques to gain new insights into the impact of these repetitive chromatin domains on the DNA repair process. Here we summarize these tools with a particular focus on Double-Strand Break (DSB) repair, and discuss the insights gained into our understanding of the influence of chromatin domains on DSB -dynamics and -repair pathway choice.
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Affiliation(s)
- Marit A E van Bueren
- Center for Molecular Medicine, University Medical Center Utrecht, Universiteitsweg 100, 3584 CG Utrecht, the Netherlands
| | - Aniek Janssen
- Center for Molecular Medicine, University Medical Center Utrecht, Universiteitsweg 100, 3584 CG Utrecht, the Netherlands.
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11
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Molina O, Ortega-Sabater C, Thampi N, Fernández-Fuentes N, Guerrero-Murillo M, Martínez-Moreno A, Vinyoles M, Velasco-Hernández T, Bueno C, Trincado JL, Granada I, Campos D, Giménez C, Boer JM, den Boer ML, Calvo GF, Camós M, Fuster JL, Velasco P, Ballerini P, Locatelli F, Mullighan CG, Spierings DCJ, Foijer F, Pérez-García VM, Menéndez P. Chromosomal instability in aneuploid acute lymphoblastic leukemia associates with disease progression. EMBO Mol Med 2024; 16:64-92. [PMID: 38177531 PMCID: PMC10897411 DOI: 10.1038/s44321-023-00006-w] [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: 08/05/2023] [Revised: 11/09/2023] [Accepted: 11/15/2023] [Indexed: 01/06/2024] Open
Abstract
Chromosomal instability (CIN) lies at the core of cancer development leading to aneuploidy, chromosomal copy-number heterogeneity (chr-CNH) and ultimately, unfavorable clinical outcomes. Despite its ubiquity in cancer, the presence of CIN in childhood B-cell acute lymphoblastic leukemia (cB-ALL), the most frequent pediatric cancer showing high frequencies of aneuploidy, remains unknown. Here, we elucidate the presence of CIN in aneuploid cB-ALL subtypes using single-cell whole-genome sequencing of primary cB-ALL samples and by generating and functionally characterizing patient-derived xenograft models (cB-ALL-PDX). We report higher rates of CIN across aneuploid than in euploid cB-ALL that strongly correlate with intraclonal chr-CNH and overall survival in mice. This association was further supported by in silico mathematical modeling. Moreover, mass-spectrometry analyses of cB-ALL-PDX revealed a "CIN signature" enriched in mitotic-spindle regulatory pathways, which was confirmed by RNA-sequencing of a large cohort of cB-ALL samples. The link between the presence of CIN in aneuploid cB-ALL and disease progression opens new possibilities for patient stratification and offers a promising new avenue as a therapeutic target in cB-ALL treatment.
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Affiliation(s)
- Oscar Molina
- Josep Carreras Leukemia Research Institute, Department of Biomedicine, School of Medicine, University of Barcelona, Barcelona, Spain.
- Red Española de Terápias Avanzadas (TERAV), Instituto de Salud Carlos III, Barcelona, Spain.
| | - Carmen Ortega-Sabater
- Mathematical Oncology Laboratory, Department of Mathematics & Institute of Applied Mathematics in Science and Engineering, Universidad de Castilla-La Mancha, Ciudad Real, Spain
| | - Namitha Thampi
- Josep Carreras Leukemia Research Institute, Department of Biomedicine, School of Medicine, University of Barcelona, Barcelona, Spain
- Red Española de Terápias Avanzadas (TERAV), Instituto de Salud Carlos III, Barcelona, Spain
| | - Narcís Fernández-Fuentes
- Josep Carreras Leukemia Research Institute, Department of Biomedicine, School of Medicine, University of Barcelona, Barcelona, Spain
- Red Española de Terápias Avanzadas (TERAV), Instituto de Salud Carlos III, Barcelona, Spain
| | - Mercedes Guerrero-Murillo
- Josep Carreras Leukemia Research Institute, Department of Biomedicine, School of Medicine, University of Barcelona, Barcelona, Spain
- Red Española de Terápias Avanzadas (TERAV), Instituto de Salud Carlos III, Barcelona, Spain
| | - Alba Martínez-Moreno
- Josep Carreras Leukemia Research Institute, Department of Biomedicine, School of Medicine, University of Barcelona, Barcelona, Spain
- Red Española de Terápias Avanzadas (TERAV), Instituto de Salud Carlos III, Barcelona, Spain
| | - Meritxell Vinyoles
- Josep Carreras Leukemia Research Institute, Department of Biomedicine, School of Medicine, University of Barcelona, Barcelona, Spain
- Red Española de Terápias Avanzadas (TERAV), Instituto de Salud Carlos III, Barcelona, Spain
| | - Talía Velasco-Hernández
- Josep Carreras Leukemia Research Institute, Department of Biomedicine, School of Medicine, University of Barcelona, Barcelona, Spain
- Red Española de Terápias Avanzadas (TERAV), Instituto de Salud Carlos III, Barcelona, Spain
| | - Clara Bueno
- Josep Carreras Leukemia Research Institute, Department of Biomedicine, School of Medicine, University of Barcelona, Barcelona, Spain
- Red Española de Terápias Avanzadas (TERAV), Instituto de Salud Carlos III, Barcelona, Spain
| | - Juan L Trincado
- Josep Carreras Leukemia Research Institute, Department of Biomedicine, School of Medicine, University of Barcelona, Barcelona, Spain
- Red Española de Terápias Avanzadas (TERAV), Instituto de Salud Carlos III, Barcelona, Spain
| | - Isabel Granada
- Hematology Service, Institut Català d'Oncologia (ICO)-Hospital Germans Trias i Pujol, Badalona, Spain
- Josep Carreras Leukemia Research Institute, Autonomous University of Barcelona, Badalona, Spain
| | | | | | - Judith M Boer
- Princess Maxima Center for Pediatric Oncology, Utrecht, The Netherlands
| | - Monique L den Boer
- Princess Maxima Center for Pediatric Oncology, Utrecht, The Netherlands
- Department of Pediatric Oncology and Hematology, Erasmus Medical Center - Sophia Children's Hospital, Rotterdam, The Netherlands
| | - Gabriel F Calvo
- Mathematical Oncology Laboratory, Department of Mathematics & Institute of Applied Mathematics in Science and Engineering, Universidad de Castilla-La Mancha, Ciudad Real, Spain
| | - Mireia Camós
- Hematology Laboratory, Hospital Sant Joan de Déu, University of Barcelona, Barcelona, Spain
- Leukemia and Other Pediatric Hemopathies, Developmental Tumor Biology Group, Institut de Recerca Hospital Sant Joan de Déu, Barcelona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | - Jose-Luis Fuster
- Pediatric Hematology and Oncology Department, Hospital Clínico Universitario Virgen de la Arrixaca, Instituto Murciano de Investigación Biosanitaria (IMIB), Murcia, Spain
| | - Pablo Velasco
- Pediatric Oncology and Hematology Department, Hospital Vall d'Hebrón, Barcelona, Spain
| | - Paola Ballerini
- AP-HP, Service of Pediatric Hematology, Hopital Armand Trousseau, Paris, France
| | - Franco Locatelli
- Bambino Gesù Children's Hospital, Catholic University of Sacred Heart, Rome, Italy
| | - Charles G Mullighan
- Department of Pathology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Diana C J Spierings
- European Research Institute for the Biology of Aging (ERIBA), University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Floris Foijer
- European Research Institute for the Biology of Aging (ERIBA), University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Víctor M Pérez-García
- Mathematical Oncology Laboratory, Department of Mathematics & Institute of Applied Mathematics in Science and Engineering, Universidad de Castilla-La Mancha, Ciudad Real, Spain
| | - Pablo Menéndez
- Josep Carreras Leukemia Research Institute, Department of Biomedicine, School of Medicine, University of Barcelona, Barcelona, Spain.
- Red Española de Terápias Avanzadas (TERAV), Instituto de Salud Carlos III, Barcelona, Spain.
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain.
- Department of Biomedicine. School of Medicine, University of Barcelona, Barcelona, Spain.
- Spanish Cancer Research Network (CIBERONC), ISCIII, Barcelona, Spain.
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12
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Chavan A, Isenhart R, Nguyen SC, Kotb N, Harke J, Sintsova A, Ulukaya G, Uliana F, Ashiono C, Kutay U, Pegoraro G, Rangan P, Joyce EF, Jagannathan M. A nuclear architecture screen in Drosophila identifies Stonewall as a link between chromatin position at the nuclear periphery and germline stem cell fate. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.17.567611. [PMID: 38014085 PMCID: PMC10680830 DOI: 10.1101/2023.11.17.567611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
The association of genomic loci to the nuclear periphery is proposed to facilitate cell-type specific gene repression and influence cell fate decisions. However, the interplay between gene position and expression remains incompletely understood, in part because the proteins that position genomic loci at the nuclear periphery remain unidentified. Here, we used an Oligopaint-based HiDRO screen targeting ~1000 genes to discover novel regulators of nuclear architecture in Drosophila cells. We identified the heterochromatin-associated protein, Stonewall (Stwl), as a factor promoting perinuclear chromatin positioning. In female germline stem cells (GSCs), Stwl binds and positions chromatin loci, including GSC differentiation genes, at the nuclear periphery. Strikingly, Stwl-dependent perinuclear positioning is associated with transcriptional repression, highlighting a likely mechanism for Stwl's known role in GSC maintenance and ovary homeostasis. Thus, our study identifies perinuclear anchors in Drosophila and demonstrates the importance of gene repression at the nuclear periphery for cell fate.
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Affiliation(s)
- Ankita Chavan
- Institute of Biochemistry, Department of Biology, ETH Zürich, Switzerland
- Bringing Materials to Life Consortium, ETH Zürich, Switzerland
- Life Science Zurich Graduate School, Zürich, Switzerland
- These authors contributed equally
| | - Randi Isenhart
- Penn Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- These authors contributed equally
| | - Son C. Nguyen
- Penn Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Noor Kotb
- Department of Cell, Developmental and Regenerative Biology, Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Jailynn Harke
- Penn Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Anna Sintsova
- Institute of Microbiology, Department of Biology, ETH Zürich, Switzerland
| | - Gulay Ulukaya
- Bioinformatics for Next Generation Sequencing (BiNGS) core, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Federico Uliana
- Institute of Biochemistry, Department of Biology, ETH Zürich, Switzerland
| | - Caroline Ashiono
- Institute of Biochemistry, Department of Biology, ETH Zürich, Switzerland
| | - Ulrike Kutay
- Institute of Biochemistry, Department of Biology, ETH Zürich, Switzerland
| | - Gianluca Pegoraro
- High Throughput Imaging Facility (HiTIF), National Cancer Institute, NIH, Bethesda, MD 20892 USA
| | - Prashanth Rangan
- Department of Cell, Developmental and Regenerative Biology, Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Eric F. Joyce
- Penn Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Madhav Jagannathan
- Institute of Biochemistry, Department of Biology, ETH Zürich, Switzerland
- Bringing Materials to Life Consortium, ETH Zürich, Switzerland
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13
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Zhang W, Suo J, Yan Y, Yang R, Lu Y, Jin Y, Gao S, Li S, Gao J, Zhang M, Dai Q. iSMOD: an integrative browser for image-based single-cell multi-omics data. Nucleic Acids Res 2023; 51:8348-8366. [PMID: 37439331 PMCID: PMC10484677 DOI: 10.1093/nar/gkad580] [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: 11/23/2022] [Revised: 06/09/2023] [Accepted: 06/26/2023] [Indexed: 07/14/2023] Open
Abstract
Genomic and transcriptomic image data, represented by DNA and RNA fluorescence in situ hybridization (FISH), respectively, together with proteomic data, particularly that related to nuclear proteins, can help elucidate gene regulation in relation to the spatial positions of chromatins, messenger RNAs, and key proteins. However, methods for image-based multi-omics data collection and analysis are lacking. To this end, we aimed to develop the first integrative browser called iSMOD (image-based Single-cell Multi-omics Database) to collect and browse comprehensive FISH and nucleus proteomics data based on the title, abstract, and related experimental figures, which integrates multi-omics studies focusing on the key players in the cell nucleus from 20 000+ (still growing) published papers. We have also provided several exemplar demonstrations to show iSMOD's wide applications-profiling multi-omics research to reveal the molecular target for diseases; exploring the working mechanism behind biological phenomena using multi-omics interactions, and integrating the 3D multi-omics data in a virtual cell nucleus. iSMOD is a cornerstone for delineating a global view of relevant research to enable the integration of scattered data and thus provides new insights regarding the missing components of molecular pathway mechanisms and facilitates improved and efficient scientific research.
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Affiliation(s)
- Weihang Zhang
- Department of Automation, Tsinghua University, Beijing 100084, China
| | - Jinli Suo
- Department of Automation, Tsinghua University, Beijing 100084, China
- Institute of Brain and Cognitive Sciences, Tsinghua University, Beijing 100084, China
- Shanghai Artificial Intelligence Laboratory, Shanghai 200232, China
| | - Yan Yan
- MOE Key Laboratory of Bioinformatics; Bioinformatics Division, BNRist; Center for Synthetic & Systems Biology, Tsinghua University, Beijing 100084, China
- School of Medicine, Tsinghua University, Beijing 100084, China
| | - Runzhao Yang
- Department of Automation, Tsinghua University, Beijing 100084, China
| | - Yiming Lu
- Department of Automation, Tsinghua University, Beijing 100084, China
| | - Yiqi Jin
- Department of Automation, Tsinghua University, Beijing 100084, China
| | - Shuochen Gao
- Department of Automation, Tsinghua University, Beijing 100084, China
| | - Shao Li
- Department of Automation, Tsinghua University, Beijing 100084, China
- MOE Key Laboratory of Bioinformatics; Bioinformatics Division, BNRist; Center for Synthetic & Systems Biology, Tsinghua University, Beijing 100084, China
| | - Juntao Gao
- MOE Key Laboratory of Bioinformatics; Bioinformatics Division, BNRist; Center for Synthetic & Systems Biology, Tsinghua University, Beijing 100084, China
- School of Medicine, Tsinghua University, Beijing 100084, China
| | - Michael Zhang
- MOE Key Laboratory of Bioinformatics; Bioinformatics Division, BNRist; Center for Synthetic & Systems Biology, Tsinghua University, Beijing 100084, China
- School of Medicine, Tsinghua University, Beijing 100084, China
| | - Qionghai Dai
- Department of Automation, Tsinghua University, Beijing 100084, China
- Institute of Brain and Cognitive Sciences, Tsinghua University, Beijing 100084, China
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14
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Mello MLS. Nuclear Morphofunctional Organization and Epigenetic Characteristics in Somatic Cells of T. infestans (Klug, 1834). Pathogens 2023; 12:1030. [PMID: 37623990 PMCID: PMC10460038 DOI: 10.3390/pathogens12081030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2023] [Revised: 08/07/2023] [Accepted: 08/08/2023] [Indexed: 08/26/2023] Open
Abstract
Triatoma infestans (Klug) is an insect recognized as not only an important vector of South American trypanosomiasis (Chagas disease) but also a model of specific cellular morphofunctional organization and epigenetic characteristics. The purpose of the present review is to highlight certain cellular processes that are particularly unveiled in T. infestans, such as the following: (1) somatic polyploidy involving nuclear and cell fusions that generate giant nuclei; (2) diversification of nuclear phenotypes in the Malpighian tubules during insect development; (3) heterochromatin compartmentalization into large bodies with specific spatial distribution and presumed mobility in the cell nuclei; (4) chromatin remodeling and co-occurrence of necrosis and apoptosis in the Malpighian tubules under stress conditions; (5) epigenetic markers; and (6) response of heterochromatin to valproic acid, an epidrug that inhibits histone deacetylases and induces DNA demethylation in other cell systems. These cellular processes and epigenetic characteristics emphasize the role of T. infestans as an attractive model for cellular research. A limitation of these studies is the availability of insect supply by accredited insectaries. For studies that require the injection of drugs, the operator's dexterity to perform insect manipulation is necessary, especially if young nymphs are used. For studies involving in vitro cultivation of insect organs, the culture medium should be carefully selected to avoid inconsistent results.
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Affiliation(s)
- Maria Luiza S Mello
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas, Campinas 13083-862, SP, Brazil
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15
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Erdel F. Phase transitions in heterochromatin organization. Curr Opin Struct Biol 2023; 80:102597. [PMID: 37087823 DOI: 10.1016/j.sbi.2023.102597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 03/13/2023] [Accepted: 03/20/2023] [Indexed: 04/25/2023]
Abstract
Heterochromatin formation has been proposed to involve phase transitions on the level of the three-dimensional folding of heterochromatin regions and the liquid-liquid demixing of heterochromatin proteins. Here, I outline the hallmarks of such transitions and the current challenges to detect them in living cells. I further discuss the abundance and properties of prominent heterochromatin proteins and relate them to their potential role in driving phase transitions. Recent data from mouse fibroblasts indicate that pericentric heterochromatin is organized via a reordering transition on the level of heterochromatin regions that does not necessarily involve liquid-liquid demixing of heterochromatin proteins. Evaluating key hallmarks of the different candidate phase transition mechanisms across cell types and species will be needed to complete the current picture.
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Affiliation(s)
- Fabian Erdel
- MCD, Center for Integrative Biology (CBI), CNRS, UPS, Toulouse, France.
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16
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Bouwman BA, Crosetto N, Bienko M. A GC-centered view of 3D genome organization. Curr Opin Genet Dev 2023; 78:102020. [PMID: 36610373 DOI: 10.1016/j.gde.2022.102020] [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: 10/21/2022] [Revised: 11/30/2022] [Accepted: 12/03/2022] [Indexed: 01/07/2023]
Abstract
In the past two decades, our understanding of how the genome of mammalian cells is spatially organized in the three-dimensional (3D) space of the nucleus and how key nuclear processes are orchestrated in this space has drastically expanded. While genome organization has been extensively studied at the nanoscale, the higher-order arrangement of individual portions of the genome with respect to their intranuclear as well as reciprocal placement is less thoroughly characterized. Emerging evidence points to the existence of a complex radial arrangement of chromatin in the nucleus. However, what shapes this radial organization and whether it has any functional implications remain elusive. In this mini review, we first summarize our current knowledge on this rather overlooked aspect of mammalian genome organization. We then present a theoretical framework for explaining how the genome might be radially organized, focusing on the role of the guanine and cytosine density along the linear genome. Last, we discuss outstanding questions, hoping to inspire future experiments and spark interest in this topic within the 3D genome community.
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Affiliation(s)
- Britta Am Bouwman
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm SE-17165, Sweden; Science for Life Laboratory, Tomtebodavägen 23A, Solna SE-17165, Sweden
| | - Nicola Crosetto
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm SE-17165, Sweden; Science for Life Laboratory, Tomtebodavägen 23A, Solna SE-17165, Sweden; Human Technopole, Viale Rita Levi-Montalcini 1, 20157 Milan, Italy
| | - Magda Bienko
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm SE-17165, Sweden; Science for Life Laboratory, Tomtebodavägen 23A, Solna SE-17165, Sweden; Human Technopole, Viale Rita Levi-Montalcini 1, 20157 Milan, Italy.
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17
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Chromosome territory reorganization through artificial chromosome fusion is compatible with cell fate determination and mouse development. Cell Discov 2023; 9:11. [PMID: 36693846 PMCID: PMC9873915 DOI: 10.1038/s41421-022-00511-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 12/18/2022] [Indexed: 01/26/2023] Open
Abstract
Chromosomes occupy discrete spaces in the interphase cell nucleus, called chromosome territory. The structural and functional relevance of chromosome territory remains elusive. We fused chromosome 15 and 17 in mouse haploid embryonic stem cells (haESCs), resulting in distinct changes of territories in the cognate chromosomes, but with little effect on gene expression, pluripotency and gamete functions of haESCs. The karyotype-engineered haESCs were successfully implemented in generating heterozygous (2n = 39) and homozygous (2n = 38) mouse models. Mice containing the fusion chromosome are fertile, and their representative tissues and organs display no phenotypic abnormalities, suggesting unscathed development. These results indicate that the mammalian chromosome architectures are highly resilient, and reorganization of chromosome territories can be readily tolerated during cell differentiation and mouse development.
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18
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Perničková K, Kopecký D. Visualizing Chromosome Territories and Nuclear Architecture of Large Plant Genomes Using Alien Introgressions. Methods Mol Biol 2023; 2672:365-376. [PMID: 37335489 DOI: 10.1007/978-1-0716-3226-0_23] [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: 06/21/2023]
Abstract
Visualization of chromosome territories is a challenging task in plant genomes due to the lack of chromosome-specific probes, especially in species with large genomes. On the other hand, combination of flow sorting, genomic in situ hybridization (GISH), confocal microscopy, and employment of software for 3D modeling enables to visualize and characterize chromosome territories (CT) in interspecific hybrids. Here, we describe the protocol for the analysis of CTs in wheat-rye and wheat-barley hybrids, including amphiploids and introgression forms, where a pair of chromosomes or chromosome arms from one species is introgressed into the genome of another species. In this way, the architecture and dynamics of CTs in various tissues and different stages of cell cycle can be analyzed.
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Affiliation(s)
- Kateřina Perničková
- Centre of Plant Structural and Functional Genomics, Institute of Experimental Botany of the Czech Academy of Sciences, Olomouc, Czech Republic
| | - David Kopecký
- Centre of Plant Structural and Functional Genomics, Institute of Experimental Botany of the Czech Academy of Sciences, Olomouc, Czech Republic.
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19
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Matveevsky S, Bakloushinskaya I, Tambovtseva V, Atsaeva M, Grishaeva T, Bogdanov A, Kolomiets O. Nonhomologous Chromosome Interactions in Prophase I: Dynamics of Bizarre Meiotic Contacts in the Alay Mole Vole Ellobius alaicus (Mammalia, Rodentia). Genes (Basel) 2022; 13:genes13122196. [PMID: 36553461 PMCID: PMC9778597 DOI: 10.3390/genes13122196] [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: 09/29/2022] [Revised: 11/18/2022] [Accepted: 11/21/2022] [Indexed: 11/25/2022] Open
Abstract
Nonhomologous chromosome interactions take place in both somatic and meiotic cells. Prior to this study, we had discovered special contacts through the SYCP3 (synaptonemal complex protein 3) filament between the short arms of nonhomologous acrocentrics at the pachytene stage in the Alay mole vole, and these contacts demonstrate several patterns from proximity to the complete fusion stage. Here, we investigated the nonhomologous chromosome contacts in meiotic prophase I. It turned out that such contacts do not introduce changes into the classic distribution of DNA double-strand breaks. It is noteworthy that not all meiotic contacts were localized in the H3k9me3-positive heterochromatic environment. Both in the mid zygotene and in the early-mid diplotene, three types of contacts (proximity, touching, and anchoring/tethering) were observed, whereas fusion seems to be characteristic only for pachytene. The number of contacts in the mid pachytene is significantly higher than that in the zygotene, and the distance between centromeres in nonhomologous contacts is also the smallest in mid pachytene for all types of contacts. Thus, this work provides a new insight into the behavior of meiotic contacts during prophase I and points to avenues of further research.
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Affiliation(s)
- Sergey Matveevsky
- Vavilov Institute of General Genetics, Russian Academy of Sciences, 119991 Moscow, Russia
- Correspondence:
| | - Irina Bakloushinskaya
- Koltzov Institute of Developmental Biology, Russian Academy of Sciences, 119334 Moscow, Russia
| | - Valentina Tambovtseva
- Koltzov Institute of Developmental Biology, Russian Academy of Sciences, 119334 Moscow, Russia
| | - Maret Atsaeva
- Vavilov Institute of General Genetics, Russian Academy of Sciences, 119991 Moscow, Russia
- Department of Cell Biology, Morphology and Microbiology, Chechen State University, 364024 Grozny, Russia
| | - Tatiana Grishaeva
- Vavilov Institute of General Genetics, Russian Academy of Sciences, 119991 Moscow, Russia
| | - Aleksey Bogdanov
- Koltzov Institute of Developmental Biology, Russian Academy of Sciences, 119334 Moscow, Russia
| | - Oxana Kolomiets
- Vavilov Institute of General Genetics, Russian Academy of Sciences, 119991 Moscow, Russia
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20
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Boldyreva LV, Andreyeva EN, Pindyurin AV. Position Effect Variegation: Role of the Local Chromatin Context in Gene Expression Regulation. Mol Biol 2022. [DOI: 10.1134/s0026893322030049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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21
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Komoto T, Fujii M, Awazu A. Epigenetic-structural changes in X chromosomes promote Xic pairing during early differentiation of mouse embryonic stem cells. Biophys Physicobiol 2022; 19:1-14. [PMID: 35797402 PMCID: PMC9174021 DOI: 10.2142/biophysico.bppb-v19.0018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 05/02/2022] [Indexed: 12/01/2022] Open
Abstract
X chromosome inactivation center (Xic) pairing occurs during the differentiation of embryonic stem (ES) cells from female mouse embryos, and is related to X chromosome inactivation, the circadian clock, intra-nucleus architecture, and metabolism. However, the mechanisms underlying the identification and approach of X chromosome pairs in the crowded nucleus are unclear. To elucidate the driving force of Xic pairing, we developed a coarse-grained molecular dynamics model of intranuclear chromosomes in ES cells and in cells 2 days after the onset of differentiation (2-day cells) by considering intrachromosomal epigenetic-structural feature-dependent mechanics. The analysis of the experimental data showed that X-chromosomes exhibit the rearrangement of their distributions of open/closed chromatin regions on their surfaces during cell differentiation. By simulating models where the excluded volume effects of closed chromatin regions are stronger than those of open chromatin regions, such rearrangement of open/closed chromatin regions on X-chromosome surfaces promoted the mutual approach of the Xic pair. These findings suggested that local intrachromosomal epigenetic features may contribute to the regulation of cell species-dependent differences in intranuclear architecture.
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Affiliation(s)
- Tetsushi Komoto
- Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526, Japan
| | - Masashi Fujii
- Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526, Japan
| | - Akinori Awazu
- Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526, Japan
- Research Center for the Mathematics on Chromatin Live Dynamics, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526, Japan
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22
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de Lima MF, Lisboa MDO, Terceiro LEL, Rangel-Pozzo A, Mai S. Chromosome Territories in Hematological Malignancies. Cells 2022; 11:1368. [PMID: 35456046 PMCID: PMC9028803 DOI: 10.3390/cells11081368] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 04/12/2022] [Accepted: 04/15/2022] [Indexed: 11/21/2022] Open
Abstract
Chromosomes are organized in distinct nuclear areas designated as chromosome territories (CT). The structural formation of CT is a consequence of chromatin packaging and organization that ultimately affects cell function. Chromosome positioning can identify structural signatures of genomic organization, especially for diseases where changes in gene expression contribute to a given phenotype. The study of CT in hematological diseases revealed chromosome position as an important factor for specific chromosome translocations. In this review, we highlight the history of CT theory, current knowledge on possible clinical applications of CT analysis, and the impact of CT in the development of hematological neoplasia such as multiple myeloma, leukemia, and lymphomas. Accumulating data on nuclear architecture in cancer allow one to propose the three-dimensional nuclear genomic landscape as a novel cancer biomarker for the future.
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Affiliation(s)
- Matheus Fabiao de Lima
- Department of Physiology and Pathophysiology, CancerCare Manitoba Research Institute, University of Manitoba, Winnipeg, MB R3E 0V9, Canada;
| | - Mateus de Oliveira Lisboa
- Core for Cell Technology, School of Medicine, Pontifícia Universidade Católica do Paraná—PUCPR, Curitiba 80215-901, Brazil;
| | - Lucas E. L. Terceiro
- Department of Pathology, Max Rady College of Medicine, University of Manitoba, Winnipeg, MB R3E 3P5, Canada;
| | - Aline Rangel-Pozzo
- Department of Physiology and Pathophysiology, CancerCare Manitoba Research Institute, University of Manitoba, Winnipeg, MB R3E 0V9, Canada;
| | - Sabine Mai
- Department of Physiology and Pathophysiology, CancerCare Manitoba Research Institute, University of Manitoba, Winnipeg, MB R3E 0V9, Canada;
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23
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Lorber D, Volk T. Evaluation of chromatin mesoscale organization. APL Bioeng 2022; 6:010902. [PMID: 35071965 PMCID: PMC8758204 DOI: 10.1063/5.0069286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Accepted: 11/29/2021] [Indexed: 11/21/2022] Open
Abstract
Chromatin organization in the nucleus represents an important aspect of transcription regulation. Most of the studies so far focused on the chromatin structure in cultured cells or in fixed tissue preparations. Here, we discuss the various approaches for deciphering chromatin 3D organization with an emphasis on the advantages of live imaging approaches.
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Affiliation(s)
- Dana Lorber
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Talila Volk
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
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24
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Brändle F, Frühbauer B, Jagannathan M. Principles and functions of pericentromeric satellite DNA clustering into chromocenters. Semin Cell Dev Biol 2022; 128:26-39. [PMID: 35144860 DOI: 10.1016/j.semcdb.2022.02.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Revised: 02/03/2022] [Accepted: 02/03/2022] [Indexed: 12/29/2022]
Abstract
Simple non-coding tandem repeats known as satellite DNA are observed widely across eukaryotes. These repeats occupy vast regions at the centromere and pericentromere of chromosomes but their contribution to cellular function has remained incompletely understood. Here, we review the literature on pericentromeric satellite DNA and discuss its organization and functions across eukaryotic species. We specifically focus on chromocenters, DNA-dense nuclear foci that contain clustered pericentromeric satellite DNA repeats from multiple chromosomes. We first discuss chromocenter formation and the roles that epigenetic modifications, satellite DNA transcripts and sequence-specific satellite DNA-binding play in this process. We then review the newly emerging functions of chromocenters in genome encapsulation, the maintenance of cell fate and speciation. We specifically highlight how the rapid divergence of satellite DNA repeats impacts reproductive isolation between closely related species. Together, we underline the importance of this so-called 'junk DNA' in fundamental biological processes.
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Affiliation(s)
- Franziska Brändle
- Institute of Biochemistry, ETH Zürich, Otto-Stern-Weg 3, Zürich CH-8093, Switzerland
| | - Benjamin Frühbauer
- Institute of Biochemistry, ETH Zürich, Otto-Stern-Weg 3, Zürich CH-8093, Switzerland
| | - Madhav Jagannathan
- Institute of Biochemistry, ETH Zürich, Otto-Stern-Weg 3, Zürich CH-8093, Switzerland.
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25
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Nustad HE, Steinsland I, Ollikainen M, Cazaly E, Kaprio J, Benjamini Y, Gervin K, Lyle R. Modeling dependency structures in 450k DNA methylation data. Bioinformatics 2022; 38:885-891. [PMID: 34788815 PMCID: PMC8796368 DOI: 10.1093/bioinformatics/btab774] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 11/01/2021] [Accepted: 11/09/2021] [Indexed: 02/04/2023] Open
Abstract
MOTIVATION DNA methylation has been shown to be spatially dependent across chromosomes. Previous studies have focused on the influence of genomic context on the dependency structure, while not considering differences in dependency structure between individuals. RESULTS We modeled spatial dependency with a flexible framework to quantify the dependency structure, focusing on inter-individual differences by exploring the association between dependency parameters and technical and biological variables. The model was applied to a subset of the Finnish Twin Cohort study (N = 1611 individuals). The estimates of the dependency parameters varied considerably across individuals, but were generally consistent across chromosomes within individuals. The variation in dependency parameters was associated with bisulfite conversion plate, zygosity, sex and age. The age differences presumably reflect accumulated environmental exposures and/or accumulated small methylation differences caused by stochastic mitotic events, establishing recognizable, individual patterns more strongly seen in older individuals. AVAILABILITY AND IMPLEMENTATION The twin dataset used in the current study are located in the Biobank of the National Institute for Health and Welfare, Finland. All the biobanked data are publicly available for use by qualified researchers following a standardized application procedure (https://thl.fi/en/web/thl-biobank/for-researchers). A R-script for fitting the dependency structure to publicly available DNA methylation data with the software used in this article is provided in supplementary data. SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Haakon E Nustad
- Department of Medical Genetics and Norwegian Sequencing Centre, Oslo University Hospital, 0450 Oslo, Norway
- Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, 0372 Oslo, Norway
- Department of Pharmacy, PharmaTox Strategic Research Initiative, University of Oslo, 0371 Oslo, Norway
- Centre for Fertility and Health, Norwegian Institute of Public Health, 0213 Oslo, Norway
| | - Ingelin Steinsland
- Department of Mathematical Sciences, Norwegian University of Science and Technology, 7034 Trondheim, Norway
| | - Miina Ollikainen
- Institute for Molecular Medicine Finland FIMM, Helsinki Institute of Life Science, University of Helsinki, FI-00014 Helsinki, Finland
| | - Emma Cazaly
- Institute for Molecular Medicine Finland FIMM, Helsinki Institute of Life Science, University of Helsinki, FI-00014 Helsinki, Finland
| | - Jaakko Kaprio
- Institute for Molecular Medicine Finland FIMM, Helsinki Institute of Life Science, University of Helsinki, FI-00014 Helsinki, Finland
| | - Yuval Benjamini
- Department of Statistics and Data Science, The Hebrew University, Mount Scopus, Jerusalem 9190501, Israel
| | - Kristina Gervin
- Department of Pharmacy, PharmaTox Strategic Research Initiative, University of Oslo, 0371 Oslo, Norway
- Division of Clinical Neuroscience, Department of Research and Innovation, Oslo University Hospital, 0450 Oslo, Norway
- Pharmacoepidemiology and Drug Safety Research Group, Department of Pharmacy, Faculty of Mathematics and Natural Sciences, University of Oslo, 0363 Oslo, Norway
| | - Robert Lyle
- Department of Medical Genetics and Norwegian Sequencing Centre, Oslo University Hospital, 0450 Oslo, Norway
- Centre for Fertility and Health, Norwegian Institute of Public Health, 0213 Oslo, Norway
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26
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Chebrout M, Koné MC, Jan HU, Cournut M, Letheule M, Fleurot R, Aguirre-Lavin T, Peynot N, Jouneau A, Beaujean N, Bonnet-Garnier A. Transcription of rRNA in early mouse embryos promotes chromatin reorganization and expression of major satellite repeats. J Cell Sci 2022; 135:274059. [DOI: 10.1242/jcs.258798] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 01/09/2022] [Indexed: 11/20/2022] Open
Abstract
During the first cell cycles of the early development, the chromatin of the embryo is highly reprogrammed alongside that embryonic genome starts its own transcription. The spatial organization of the genome is a major process that contributes to regulating gene transcription in time and space, however, it is poorly studied in the context of early embryos. To study the cause and effect link between transcription and spatial organization in embryos, we focused on the ribosomal genes, that are first silent and begin to transcribe during the 2-cell stage in the mouse. We demonstrated that ribosomal sequences and early unprocessed rRNAs are spatially organized in a very peculiar manner from the 2-cell to the 16-cell. Using drugs interfering with ribosomal DNA transcription, we show that this organization, totally different from somatic cells, depends on an active transcription of ribosomal genes and induces a unique chromatin environment that favors transcription of major satellite sequences after the 4-cell stage.
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Affiliation(s)
- Martine Chebrout
- Université Paris-Saclay, UVSQ, INRAE, BREED, 78350, Jouy-en-Josas, France
- Ecole Nationale Vétérinaire d'Alfort, BREED, 94700, Maisons-Alfort, France
| | - Maïmouna Coura Koné
- Université Paris-Saclay, UVSQ, INRAE, BREED, 78350, Jouy-en-Josas, France
- Ecole Nationale Vétérinaire d'Alfort, BREED, 94700, Maisons-Alfort, France
| | - Habib U. Jan
- Université Paris-Saclay, UVSQ, INRAE, BREED, 78350, Jouy-en-Josas, France
- Ecole Nationale Vétérinaire d'Alfort, BREED, 94700, Maisons-Alfort, France
| | - Marie Cournut
- Université Paris-Saclay, UVSQ, INRAE, BREED, 78350, Jouy-en-Josas, France
- Ecole Nationale Vétérinaire d'Alfort, BREED, 94700, Maisons-Alfort, France
| | - Martine Letheule
- Université Paris-Saclay, UVSQ, INRAE, BREED, 78350, Jouy-en-Josas, France
- Ecole Nationale Vétérinaire d'Alfort, BREED, 94700, Maisons-Alfort, France
| | - Renaud Fleurot
- Université Paris-Saclay, UVSQ, INRAE, BREED, 78350, Jouy-en-Josas, France
- Ecole Nationale Vétérinaire d'Alfort, BREED, 94700, Maisons-Alfort, France
| | - Tiphaine Aguirre-Lavin
- Université Paris-Saclay, UVSQ, INRAE, BREED, 78350, Jouy-en-Josas, France
- Ecole Nationale Vétérinaire d'Alfort, BREED, 94700, Maisons-Alfort, France
| | - Nathalie Peynot
- Université Paris-Saclay, UVSQ, INRAE, BREED, 78350, Jouy-en-Josas, France
- Ecole Nationale Vétérinaire d'Alfort, BREED, 94700, Maisons-Alfort, France
| | - Alice Jouneau
- Université Paris-Saclay, UVSQ, INRAE, BREED, 78350, Jouy-en-Josas, France
- Ecole Nationale Vétérinaire d'Alfort, BREED, 94700, Maisons-Alfort, France
| | - Nathalie Beaujean
- Université Paris-Saclay, UVSQ, INRAE, BREED, 78350, Jouy-en-Josas, France
- Ecole Nationale Vétérinaire d'Alfort, BREED, 94700, Maisons-Alfort, France
| | - Amélie Bonnet-Garnier
- Université Paris-Saclay, UVSQ, INRAE, BREED, 78350, Jouy-en-Josas, France
- Ecole Nationale Vétérinaire d'Alfort, BREED, 94700, Maisons-Alfort, France
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27
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Hua LL, Casas C, Mikawa T. Mitotic Antipairing of Homologous Chromosomes. Results Probl Cell Differ 2022; 70:191-220. [PMID: 36348108 PMCID: PMC9731508 DOI: 10.1007/978-3-031-06573-6_6] [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: 11/09/2022]
Abstract
Chromosome organization is highly dynamic and plays an essential role during cell function. It was recently found that pairs of the homologous chromosomes are continuously separated at mitosis and display a haploid (1n) chromosome set, or "antipairing," organization in human cells. Here, we provide an introduction to the current knowledge of homologous antipairing in humans and its implications in human disease.
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Affiliation(s)
- Lisa L. Hua
- Department of Biology, Sonoma State University, San Francisco
| | - Christian Casas
- Department of Biology, Sonoma State University, San Francisco
| | - Takashi Mikawa
- Department of Anatomy, Cardiovascular Research Institute, University of California, San Francisco,Corresponding author:
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28
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Chromosomal Rearrangements and Altered Nuclear Organization: Recent Mechanistic Models in Cancer. Cancers (Basel) 2021; 13:cancers13225860. [PMID: 34831011 PMCID: PMC8616464 DOI: 10.3390/cancers13225860] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 11/09/2021] [Accepted: 11/19/2021] [Indexed: 01/07/2023] Open
Abstract
Simple Summary New methodologies and technologies developed in the last few decades have highlighted the precise spatial organization of the genome into the cell nucleus, with chromatin architecture playing a central role in controlling several genome functions. Genes are expressed in a well-defined way and at a well-defined time during cell differentiation, and alterations in genome organization can lead to genetic diseases, such as cancers. Here we review how the genome is organized in the cell nucleus and the evidence of genome misorganization leading to cancer diseases. Abstract The last decade has seen significant progress in understanding how the genome is organized spatially within interphase nuclei. Recent analyses have confirmed earlier molecular cytogenetic studies on chromosome positioning within interphase nuclei and provided new information about the topologically associated domains (TADs). Examining the nuances of how genomes are organized within interphase nuclei will provide information fundamental to understanding gene regulation and expression in health and disease. Indeed, the radial spatial positioning of individual gene loci within nuclei has been associated with up- and down-regulation of specific genes, and disruption of normal genome organization within nuclei will result in compromised cellular health. In cancer cells, where reorganization of the nuclear architecture may occur in the presence of chromosomal rearrangements such as translocations, inversions, or deletions, gene repositioning can change their expression. To date, very few studies have focused on radial gene positioning and the correlation to gene expression in cancers. Further investigations would improve our understanding of the biological mechanisms at the basis of cancer and, in particular, in leukemia initiation and progression, especially in those cases where the molecular consequences of chromosomal rearrangements are still unclear. In this review, we summarize the main milestones in the field of genome organization in the nucleus and the alterations to this organization that can lead to cancer diseases.
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29
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Takei Y, Zheng S, Yun J, Shah S, Pierson N, White J, Schindler S, Tischbirek CH, Yuan GC, Cai L. Single-cell nuclear architecture across cell types in the mouse brain. Science 2021; 374:586-594. [PMID: 34591592 DOI: 10.1126/science.abj1966] [Citation(s) in RCA: 66] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Diverse cell types in tissues have distinct gene expression programs, chromatin states, and nuclear architectures. To correlate such multimodal information across thousands of single cells in mouse brain tissue sections, we use integrated spatial genomics, imaging thousands of genomic loci along with RNAs and epigenetic markers simultaneously in individual cells. We reveal that cell type–specific association and scaffolding of DNA loci around nuclear bodies organize the nuclear architecture and correlate with differential expression levels in different cell types. At the submegabase level, active and inactive X chromosomes access similar domain structures in single cells despite distinct epigenetic and expression states. This work represents a major step forward in linking single-cell three-dimensional nuclear architecture, gene expression, and epigenetic modifications in a native tissue context.
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Affiliation(s)
- Yodai Takei
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Shiwei Zheng
- Department of Genetics and Genomic Sciences and Charles Bronfman Institute for Personalized Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Jina Yun
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Sheel Shah
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Nico Pierson
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Jonathan White
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Simone Schindler
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Carsten H Tischbirek
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Guo-Cheng Yuan
- Department of Genetics and Genomic Sciences and Charles Bronfman Institute for Personalized Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Long Cai
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
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30
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Mohanta TK, Mishra AK, Al-Harrasi A. The 3D Genome: From Structure to Function. Int J Mol Sci 2021; 22:11585. [PMID: 34769016 PMCID: PMC8584255 DOI: 10.3390/ijms222111585] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 10/18/2021] [Accepted: 10/20/2021] [Indexed: 01/09/2023] Open
Abstract
The genome is the most functional part of a cell, and genomic contents are organized in a compact three-dimensional (3D) structure. The genome contains millions of nucleotide bases organized in its proper frame. Rapid development in genome sequencing and advanced microscopy techniques have enabled us to understand the 3D spatial organization of the genome. Chromosome capture methods using a ligation approach and the visualization tool of a 3D genome browser have facilitated detailed exploration of the genome. Topologically associated domains (TADs), lamin-associated domains, CCCTC-binding factor domains, cohesin, and chromatin structures are the prominent identified components that encode the 3D structure of the genome. Although TADs are the major contributors to 3D genome organization, they are absent in Arabidopsis. However, a few research groups have reported the presence of TAD-like structures in the plant kingdom.
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Affiliation(s)
- Tapan Kumar Mohanta
- Natural and Medical Sciences Research Center, University of Nizwa, Nizwa 616, Oman
| | - Awdhesh Kumar Mishra
- Department of Biotechnology, Yeungnam University, Gyeongsan 38541, Gyeongsangbuk-do, Korea; or
| | - Ahmed Al-Harrasi
- Natural and Medical Sciences Research Center, University of Nizwa, Nizwa 616, Oman
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31
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Zimatore G, Tsuchiya M, Hashimoto M, Kasperski A, Giuliani A. Self-organization of whole-gene expression through coordinated chromatin structural transition. BIOPHYSICS REVIEWS 2021; 2:031303. [PMID: 38505632 PMCID: PMC10903504 DOI: 10.1063/5.0058511] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 08/20/2021] [Indexed: 03/21/2024]
Abstract
The human DNA molecule is a 2-m-long polymer collapsed into the micrometer space of the cell nucleus. This simple consideration rules out any "Maxwell demon"-like explanation of regulation in which a single regulatory molecule (e.g., a transcription factor) finds autonomously its way to the particular target gene whose expression must be repressed or enhanced. A gene-by-gene regulation is still more contrasting with the physical reality when in the presence of cell state transitions involving the contemporary expression change of thousands of genes. This state of affair asks for a statistical mechanics inspired approach where specificity arises from a selective unfolding of chromatin driving the rewiring of gene expression pattern. The arising of "expression waves" marking state transitions related to chromatin structural reorganization through self-organized critical control of whole-genome expression will be described in the present paper. We adopt as a model system the gene expression time course of a cancer cell (MCF-7) population exposed to an efficient stimulus causing a state transition in comparison with an ineffective stimulus. The obtained results will be put into the perspective of biological adaptive systems living on the edge of chaos.
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Affiliation(s)
- Giovanna Zimatore
- eCampus University, 22060 Novedrate, Como, Italy and CNR-IMM Bologna, Italy
| | - Masa Tsuchiya
- SEIKO Life Science Laboratory, SEIKO Research Institute for Education, Osaka 540-659, Japan
| | - Midori Hashimoto
- Japan Fisheries Research and Education Agency, Kanagawa 236-8648, Japan
| | - Andrzej Kasperski
- Institute of Biological Sciences, Department of Biotechnology, University of Zielona Góra, ul. Szafrana 1, 65-516 Zielona Góra, Poland
| | - Alessandro Giuliani
- Environment and Health Department, Istituto Superiore di Sanitá, 00161 Rome, Italy
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32
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Dehghani H. Regulation of Chromatin Organization in Cell Stemness: The Emerging Role of Long Non-coding RNAs. Stem Cell Rev Rep 2021; 17:2042-2053. [PMID: 34181184 DOI: 10.1007/s12015-021-10209-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/17/2021] [Indexed: 12/27/2022]
Abstract
Chromatin is organized as chromosome territories in the nucleus of an interphase cell. The cell-type- and cell-state-specific organization of chromatin including the location, volume, compaction level, and spatial arrangement of chromosome territories are the major determinants of genome function. In addition, in response to different signaling stimuli and regulatory cues, it is the dynamic adaptation of chromatin structure that establishes and organizes transcriptional programs. It is known that varying levels of stemness are defined by gene regulatory networks. Accordingly, chromatin is the main milieu to host the transcriptional programs and gene regulatory networks responsible for the stemness status of a cell. In this review, our current understanding of the spatial organization of chromatin and the ways by which it defines stemness are discussed. In particular, the role of lncRNAs that regulate and affect chromatin organization and stemness properties are delineated. These roles can be categorized into the topics of specific binding to and epigenetic regulation of the promoter of pluripotency genes, their interaction with transcription factors, coordinating the intra- and inter-chromosomal looping of pluripotency-related genes, and their RNA-independent functions. This review brings together the results of studies that have begun to clarify the emerging roles of lncRNAs in the regulation of chromatin organization adapted for stemness and cancer plasticity.
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Affiliation(s)
- Hesam Dehghani
- Stem Cell Biology and Regenerative Medicine Research Group, Research Institute of Biotechnology, Ferdowsi University of Mashhad, Mashhad, Iran.
- Division of Biotechnology, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran.
- Department of Basic Sciences, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran.
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33
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Sajid A, Lalani EN, Chen B, Hashimoto T, Griffin DK, Bhartiya A, Thompson G, Robinson IK, Yusuf M. Ultra-Structural Imaging Provides 3D Organization of 46 Chromosomes of a Human Lymphocyte Prophase Nucleus. Int J Mol Sci 2021; 22:ijms22115987. [PMID: 34206020 PMCID: PMC8198510 DOI: 10.3390/ijms22115987] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 05/21/2021] [Accepted: 05/23/2021] [Indexed: 11/18/2022] Open
Abstract
Three dimensional (3D) ultra-structural imaging is an important tool for unraveling the organizational structure of individual chromosomes at various stages of the cell cycle. Performing hitherto uninvestigated ultra-structural analysis of the human genome at prophase, we used serial block-face scanning electron microscopy (SBFSEM) to understand chromosomal architectural organization within 3D nuclear space. Acquired images allowed us to segment, reconstruct, and extract quantitative 3D structural information about the prophase nucleus and the preserved, intact individual chromosomes within it. Our data demonstrate that each chromosome can be identified with its homolog and classified into respective cytogenetic groups. Thereby, we present the first 3D karyotype built from the compact axial structure seen on the core of all prophase chromosomes. The chromosomes display parallel-aligned sister chromatids with familiar chromosome morphologies with no crossovers. Furthermore, the spatial positions of all 46 chromosomes revealed a pattern showing a gene density-based correlation and a neighborhood map of individual chromosomes based on their relative spatial positioning. A comprehensive picture of 3D chromosomal organization at the nanometer level in a single human lymphocyte cell is presented.
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Affiliation(s)
- Atiqa Sajid
- Centre for Regenerative Medicine and Stem Cell Research, Aga Khan University, Karachi 74800, Pakistan; (A.S.); (E.-N.L.)
| | - El-Nasir Lalani
- Centre for Regenerative Medicine and Stem Cell Research, Aga Khan University, Karachi 74800, Pakistan; (A.S.); (E.-N.L.)
| | - Bo Chen
- London Centre for Nanotechnology, University College London, London WC1H 0AH, UK; (B.C.); (A.B.); (I.K.R.)
- School of Materials Science and Engineering, Tongji University, Shanghai 201804, China
- Key Laboratory of Performance Evolution and Control for Engineering Structures of the Ministry of Education, Tongji University, Shanghai 200092, China
| | - Teruo Hashimoto
- Department of Materials, University of Manchester, Oxford Road, Manchester M13 9PL, UK; (T.H.); (G.T.)
| | | | - Archana Bhartiya
- London Centre for Nanotechnology, University College London, London WC1H 0AH, UK; (B.C.); (A.B.); (I.K.R.)
| | - George Thompson
- Department of Materials, University of Manchester, Oxford Road, Manchester M13 9PL, UK; (T.H.); (G.T.)
| | - Ian K. Robinson
- London Centre for Nanotechnology, University College London, London WC1H 0AH, UK; (B.C.); (A.B.); (I.K.R.)
- Brookhaven National Laboratory, Upton, NY 11973, USA
| | - Mohammed Yusuf
- Centre for Regenerative Medicine and Stem Cell Research, Aga Khan University, Karachi 74800, Pakistan; (A.S.); (E.-N.L.)
- London Centre for Nanotechnology, University College London, London WC1H 0AH, UK; (B.C.); (A.B.); (I.K.R.)
- Correspondence:
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34
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Kundu S, Ray MD, Sharma A. Interplay between genome organization and epigenomic alterations of pericentromeric DNA in cancer. J Genet Genomics 2021; 48:184-197. [PMID: 33840602 DOI: 10.1016/j.jgg.2021.02.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2020] [Revised: 02/07/2021] [Accepted: 02/20/2021] [Indexed: 12/16/2022]
Abstract
In eukaryotic genome biology, the genomic organization inside the three-dimensional (3D) nucleus is highly complex, and whether this organization governs gene expression is poorly understood. Nuclear lamina (NL) is a filamentous meshwork of proteins present at the lining of inner nuclear membrane that serves as an anchoring platform for genome organization. Large chromatin domains termed as lamina-associated domains (LADs), play a major role in silencing genes at the nuclear periphery. The interaction of the NL and genome is dynamic and stochastic. Furthermore, many genes change their positions during developmental processes or under disease conditions such as cancer, to activate certain sorts of genes and/or silence others. Pericentromeric heterochromatin (PCH) is mostly in the silenced region within the genome, which localizes at the nuclear periphery. Studies show that several genes located at the PCH are aberrantly expressed in cancer. The interesting question is that despite being localized in the pericentromeric region, how these genes still manage to overcome pericentromeric repression. Although epigenetic mechanisms control the expression of the pericentromeric region, recent studies about genome organization and genome-nuclear lamina interaction have shed light on a new aspect of pericentromeric gene regulation through a complex and coordinated interplay between epigenomic remodeling and genomic organization in cancer.
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Affiliation(s)
- Subhadip Kundu
- Laboratory of Chromatin and Cancer Epigenetics, Department of Biochemistry, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India
| | - M D Ray
- Department of Surgical Oncology, IRCH, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India
| | - Ashok Sharma
- Laboratory of Chromatin and Cancer Epigenetics, Department of Biochemistry, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India.
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35
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Abstract
In the past several decades, the establishment of in vitro models of pluripotency has ushered in a golden era for developmental and stem cell biology. Research in this arena has led to profound insights into the regulatory features that shape early embryonic development. Nevertheless, an integrative theory of the epigenetic principles that govern the pluripotent nucleus remains elusive. Here, we summarize the epigenetic characteristics that define the pluripotent state. We cover what is currently known about the epigenome of pluripotent stem cells and reflect on the use of embryonic stem cells as an experimental system. In addition, we highlight insights from super-resolution microscopy, which have advanced our understanding of the form and function of chromatin, particularly its role in establishing the characteristically "open chromatin" of pluripotent nuclei. Further, we discuss the rapid improvements in 3C-based methods, which have given us a means to investigate the 3D spatial organization of the pluripotent genome. This has aided the adaptation of prior notions of a "pluripotent molecular circuitry" into a more holistic model, where hotspots of co-interacting domains correspond with the accumulation of pluripotency-associated factors. Finally, we relate these earlier hypotheses to an emerging model of phase separation, which posits that a biophysical mechanism may presuppose the formation of a pluripotent-state-defining transcriptional program.
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Affiliation(s)
| | - Eran Meshorer
- Department of Genetics, the Institute of Life Sciences
- Edmond and Lily Safra Center for Brain Sciences (ELSC), The Hebrew University of Jerusalem, Jerusalem, Israel 9190400
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36
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Rausch C, Weber P, Prorok P, Hörl D, Maiser A, Lehmkuhl A, Chagin VO, Casas-Delucchi CS, Leonhardt H, Cardoso MC. Developmental differences in genome replication program and origin activation. Nucleic Acids Res 2021; 48:12751-12777. [PMID: 33264404 PMCID: PMC7736824 DOI: 10.1093/nar/gkaa1124] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 10/09/2020] [Accepted: 11/04/2020] [Indexed: 12/17/2022] Open
Abstract
To ensure error-free duplication of all (epi)genetic information once per cell cycle, DNA replication follows a cell type and developmental stage specific spatio-temporal program. Here, we analyze the spatio-temporal DNA replication progression in (un)differentiated mouse embryonic stem (mES) cells. Whereas telomeres replicate throughout S-phase, we observe mid S-phase replication of (peri)centromeric heterochromatin in mES cells, which switches to late S-phase replication upon differentiation. This replication timing reversal correlates with and depends on an increase in condensation and a decrease in acetylation of chromatin. We further find synchronous duplication of the Y chromosome, marking the end of S-phase, irrespectively of the pluripotency state. Using a combination of single-molecule and super-resolution microscopy, we measure molecular properties of the mES cell replicon, the number of replication foci active in parallel and their spatial clustering. We conclude that each replication nanofocus in mES cells corresponds to an individual replicon, with up to one quarter representing unidirectional forks. Furthermore, with molecular combing and genome-wide origin mapping analyses, we find that mES cells activate twice as many origins spaced at half the distance than somatic cells. Altogether, our results highlight fundamental developmental differences on progression of genome replication and origin activation in pluripotent cells.
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Affiliation(s)
- Cathia Rausch
- Department of Biology, Technical University of Darmstadt, 64287 Darmstadt, Germany
| | - Patrick Weber
- Department of Biology, Technical University of Darmstadt, 64287 Darmstadt, Germany
| | - Paulina Prorok
- Department of Biology, Technical University of Darmstadt, 64287 Darmstadt, Germany
| | - David Hörl
- Department of Biology II, LMU Munich, 81377 Munich, Germany
| | - Andreas Maiser
- Department of Biology II, LMU Munich, 81377 Munich, Germany
| | - Anne Lehmkuhl
- Department of Biology, Technical University of Darmstadt, 64287 Darmstadt, Germany
| | - Vadim O Chagin
- Department of Biology, Technical University of Darmstadt, 64287 Darmstadt, Germany.,Institute of Cytology, Russian Academy of Sciences, St. Petersburg, Russia
| | | | | | - M Cristina Cardoso
- Department of Biology, Technical University of Darmstadt, 64287 Darmstadt, Germany
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37
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Spatial modeling of biological patterns shows multiscale organization of Arabidopsis thaliana heterochromatin. Sci Rep 2021; 11:323. [PMID: 33431919 PMCID: PMC7801681 DOI: 10.1038/s41598-020-79158-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 12/01/2020] [Indexed: 01/29/2023] Open
Abstract
The spatial organization in the cell nucleus is tightly linked to genome functions such as gene regulation. Similarly, specific spatial arrangements of biological components such as macromolecular complexes, organelles and cells are involved in many biological functions. Spatial interactions among elementary components of biological systems define their relative positioning and are key determinants of spatial patterns. However, biological variability and the lack of appropriate spatial statistical methods and models limit our current ability to analyze these interactions. Here, we developed a framework to dissect spatial interactions and organization principles by combining unbiased statistical tests, multiple spatial descriptors and new spatial models. We used plant constitutive heterochromatin as a model system to demonstrate the potential of our framework. Our results challenge the common view of a peripheral organization of chromocenters, showing that chromocenters are arranged along both radial and lateral directions in the nuclear space and obey a multiscale organization with scale-dependent antagonistic effects. The proposed generic framework will be useful to identify determinants of spatial organizations and to question their interplay with biological functions.
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38
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Nand A, Zhan Y, Salazar OR, Aranda M, Voolstra CR, Dekker J. Genetic and spatial organization of the unusual chromosomes of the dinoflagellate Symbiodinium microadriaticum. Nat Genet 2021; 53:618-629. [PMID: 33927399 PMCID: PMC8110479 DOI: 10.1038/s41588-021-00841-y] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 03/09/2021] [Indexed: 02/02/2023]
Abstract
Dinoflagellates are main primary producers in the oceans, the cause of algal blooms and endosymbionts of marine invertebrates. Much remains to be understood about their biology, including their peculiar crystalline chromosomes. We assembled 94 chromosome-scale scaffolds of the genome of the coral endosymbiont Symbiodinium microadriaticum and analyzed their organization. Genes are enriched towards the ends of chromosomes and are arranged in alternating unidirectional blocks. Some chromosomes are enriched for genes involved in specific biological processes. The chromosomes fold as linear rods and each is composed of a series of structural domains separated by boundaries. Domain boundaries are positioned at sites where transcription of two gene blocks converges and disappear when cells are treated with chemicals that block transcription, indicating correlations between gene orientation, transcription and chromosome folding. The description of the genetic and spatial organization of the S. microadriaticum genome provides a foundation for deeper exploration of the extraordinary biology of dinoflagellates and their chromosomes.
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Affiliation(s)
- Ankita Nand
- grid.168645.80000 0001 0742 0364Program in Systems Biology, Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA USA
| | - Ye Zhan
- grid.168645.80000 0001 0742 0364Program in Systems Biology, Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA USA
| | - Octavio R. Salazar
- grid.45672.320000 0001 1926 5090Biological and Environmental Sciences & Engineering Division (BESE), Red Sea Research Center (RSRC), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Manuel Aranda
- grid.45672.320000 0001 1926 5090Biological and Environmental Sciences & Engineering Division (BESE), Red Sea Research Center (RSRC), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Christian R. Voolstra
- grid.9811.10000 0001 0658 7699Department of Biology, University of Konstanz, Konstanz, Germany
| | - Job Dekker
- grid.168645.80000 0001 0742 0364Program in Systems Biology, Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA USA ,grid.413575.10000 0001 2167 1581Howard Hughes Medical Institute, Chevy Chase, MD USA
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39
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Strickfaden H. Reflections on the organization and the physical state of chromatin in eukaryotic cells. Genome 2020; 64:311-325. [PMID: 33306433 DOI: 10.1139/gen-2020-0132] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
In recent years, our perception of chromatin structure and organization in the cell nucleus has changed in fundamental ways. The 30 nm chromatin fiber has lost its status as an essential in vivo structure. Hi-C and related biochemical methods, advanced electron and super-resolved fluorescence microscopy, together with concepts from soft matter physics, have revolutionized the field. A comprehensive understanding of the structural and functional interactions that regulate cell cycle and cell type specific nuclear functions appears within reach, but it requires the integration of top-down and bottom-up approachs. In this review, I present an update on nuclear architecture studies with an emphasis on organization and the controversy regarding the physical state of chromatin in cells.
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Affiliation(s)
- Hilmar Strickfaden
- Departments of Cell Biology and Oncology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada.,Departments of Cell Biology and Oncology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
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40
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Linke V, Overmyer KA, Miller IJ, Brademan DR, Hutchins PD, Trujillo EA, Reddy TR, Russell JD, Cushing EM, Schueler KL, Stapleton DS, Rabaglia ME, Keller MP, Gatti DM, Keele GR, Pham D, Broman KW, Churchill GA, Attie AD, Coon JJ. A large-scale genome-lipid association map guides lipid identification. Nat Metab 2020; 2:1149-1162. [PMID: 32958938 PMCID: PMC7572687 DOI: 10.1038/s42255-020-00278-3] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 08/11/2020] [Indexed: 12/13/2022]
Abstract
Despite the crucial roles of lipids in metabolism, we are still at the early stages of comprehensively annotating lipid species and their genetic basis. Mass spectrometry-based discovery lipidomics offers the potential to globally survey lipids and their relative abundances in various biological samples. To discover the genetics of lipid features obtained through high-resolution liquid chromatography-tandem mass spectrometry, we analysed liver and plasma from 384 diversity outbred mice, and quantified 3,283 molecular features. These features were mapped to 5,622 lipid quantitative trait loci and compiled into a public web resource termed LipidGenie. The data are cross-referenced to the human genome and offer a bridge between genetic associations in humans and mice. Harnessing this resource, we used genome-lipid association data as an additional aid to identify a number of lipids, for example gangliosides through their association with B4galnt1, and found evidence for a group of sex-specific phosphatidylcholines through their shared locus. Finally, LipidGenie's ability to query either mass or gene-centric terms suggests acyl-chain-specific functions for proteins of the ABHD family.
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Affiliation(s)
- Vanessa Linke
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - Katherine A Overmyer
- Morgridge Institute for Research, Madison, WI, USA
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - Ian J Miller
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - Dain R Brademan
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - Paul D Hutchins
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - Edna A Trujillo
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - Thiru R Reddy
- Morgridge Institute for Research, Madison, WI, USA
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI, USA
| | | | - Emily M Cushing
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - Kathryn L Schueler
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - Donald S Stapleton
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - Mary E Rabaglia
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - Mark P Keller
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA
| | | | | | - Duy Pham
- The Jackson Laboratory, Bar Harbor, ME, USA
| | - Karl W Broman
- Department of Biostatistics and Medical Informatics, University of Wisconsin-Madison, Madison, WI, USA
| | | | - Alan D Attie
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - Joshua J Coon
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, USA.
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI, USA.
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41
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Manzella G, Schreck LD, Breunis WB, Molenaar J, Merks H, Barr FG, Sun W, Römmele M, Zhang L, Tchinda J, Ngo QA, Bode P, Delattre O, Surdez D, Rekhi B, Niggli FK, Schäfer BW, Wachtel M. Phenotypic profiling with a living biobank of primary rhabdomyosarcoma unravels disease heterogeneity and AKT sensitivity. Nat Commun 2020; 11:4629. [PMID: 32934208 PMCID: PMC7492191 DOI: 10.1038/s41467-020-18388-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Accepted: 08/18/2020] [Indexed: 12/14/2022] Open
Abstract
Cancer therapy is currently shifting from broadly used cytotoxic drugs to patient-specific precision therapies. Druggable driver oncogenes, identified by molecular analyses, are present in only a subset of patients. Functional profiling of primary tumor cells could circumvent these limitations, but suitable platforms are unavailable for most cancer entities. Here, we describe an in vitro drug profiling platform for rhabdomyosarcoma (RMS), using a living biobank composed of twenty RMS patient-derived xenografts (PDX) for high-throughput drug testing. Optimized in vitro conditions preserve phenotypic and molecular characteristics of primary PDX cells and are compatible with propagation of cells directly isolated from patient tumors. Besides a heterogeneous spectrum of responses of largely patient-specific vulnerabilities, profiling with a large drug library reveals a strong sensitivity towards AKT inhibitors in a subgroup of RMS. Overall, our study highlights the feasibility of in vitro drug profiling of primary RMS for patient-specific treatment selection in a co-clinical setting. Patient-specific precision medicine approaches are important for future cancer therapies. Here, the authors show that functional drug profiling with Rhabdomyosarcoma cells isolated from PDX and primary patient tumors uncovers patient-specific vulnerabilities.
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Affiliation(s)
- Gabriele Manzella
- University Children's Hospital, Department of Oncology and Children's Research Center, Steinwiesstrasse 75, CH-8032, Zurich, Switzerland
| | - Leonie D Schreck
- University Children's Hospital, Department of Oncology and Children's Research Center, Steinwiesstrasse 75, CH-8032, Zurich, Switzerland
| | - Willemijn B Breunis
- University Children's Hospital, Department of Oncology and Children's Research Center, Steinwiesstrasse 75, CH-8032, Zurich, Switzerland.,Princess Máxima Center for Pediatric Oncology, Uppsalalaan 8, 3584, CT, Utrecht, The Netherlands
| | - Jan Molenaar
- Princess Máxima Center for Pediatric Oncology, Uppsalalaan 8, 3584, CT, Utrecht, The Netherlands
| | - Hans Merks
- Princess Máxima Center for Pediatric Oncology, Uppsalalaan 8, 3584, CT, Utrecht, The Netherlands
| | - Frederic G Barr
- Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, Bethesda, MD, 20892, USA
| | - Wenyue Sun
- Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, Bethesda, MD, 20892, USA
| | - Michaela Römmele
- University Children's Hospital, Department of Oncology and Children's Research Center, Steinwiesstrasse 75, CH-8032, Zurich, Switzerland
| | - Luduo Zhang
- University Children's Hospital, Department of Oncology and Children's Research Center, Steinwiesstrasse 75, CH-8032, Zurich, Switzerland
| | - Joelle Tchinda
- University Children's Hospital, Department of Oncology and Children's Research Center, Steinwiesstrasse 75, CH-8032, Zurich, Switzerland
| | - Quy A Ngo
- University Children's Hospital, Department of Oncology and Children's Research Center, Steinwiesstrasse 75, CH-8032, Zurich, Switzerland
| | - Peter Bode
- University Hospital Zurich, Institute of Surgical Pathology, Schmelzbergstrasse 12, CH-8091, Zurich, Switzerland
| | - Olivier Delattre
- France INSERM U830, Équipe Labellisé LNCC, PSL Université, SIREDO Oncology Centre, Institut Curie, Paris, France
| | - Didier Surdez
- France INSERM U830, Équipe Labellisé LNCC, PSL Université, SIREDO Oncology Centre, Institut Curie, Paris, France
| | - Bharat Rekhi
- Tata Memorial Hospital, Department of Pathology, Dr E.B. road, Parel, Mumbai, 400012, India
| | - Felix K Niggli
- University Children's Hospital, Department of Oncology and Children's Research Center, Steinwiesstrasse 75, CH-8032, Zurich, Switzerland
| | - Beat W Schäfer
- University Children's Hospital, Department of Oncology and Children's Research Center, Steinwiesstrasse 75, CH-8032, Zurich, Switzerland.
| | - Marco Wachtel
- University Children's Hospital, Department of Oncology and Children's Research Center, Steinwiesstrasse 75, CH-8032, Zurich, Switzerland
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42
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Han Z, Cui K, Placek K, Hong N, Lin C, Chen W, Zhao K, Jin W. Diploid genome architecture revealed by multi-omic data of hybrid mice. Genome Res 2020; 30:1097-1106. [PMID: 32759226 PMCID: PMC7462080 DOI: 10.1101/gr.257568.119] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 07/23/2020] [Indexed: 12/24/2022]
Abstract
Although mammalian genomes are diploid, previous studies extensively investigated the average chromatin architectures without considering the differences between homologous chromosomes. We generated Hi-C, ChIP-seq, and RNA-seq data sets from CD4 T cells of B6, Cast, and hybrid mice, to investigate the diploid chromatin organization and epigenetic regulation. Our data indicate that inter-chromosomal interaction patterns between homologous chromosomes are similar, and the similarity is highly correlated with their allelic coexpression levels. Reconstruction of the 3D nucleus revealed that distances of the homologous chromosomes to the center of nucleus are almost the same. The inter-chromosomal interactions at centromere ends are significantly weaker than those at telomere ends, suggesting that they are located in different regions within the chromosome territories. The majority of A|B compartments or topologically associated domains (TADs) are consistent between B6 and Cast. We found 58% of the haploids in hybrids maintain their parental compartment status at B6/Cast divergent compartments owing to cis effect. About 95% of the trans-effected B6/Cast divergent compartments converge to the same compartment status potentially because of a shared cellular environment. We showed the differentially expressed genes between the two haploids in hybrid were associated with either genetic or epigenetic effects. In summary, our multi-omics data from the hybrid mice provided haploid-specific information on the 3D nuclear architecture and a rich resource for further understanding the epigenetic regulation of haploid-specific gene expression.
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Affiliation(s)
- Zhijun Han
- Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China.,Institute of Life Sciences, Southeast University, Nanjing, Jiangsu 210096, China
| | - Kairong Cui
- Systems Biology Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Katarzyna Placek
- Systems Biology Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Ni Hong
- Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Chengqi Lin
- Institute of Life Sciences, Southeast University, Nanjing, Jiangsu 210096, China
| | - Wei Chen
- Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Keji Zhao
- Systems Biology Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Wenfei Jin
- Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
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43
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Golczyk H, Limanówka A, Uchman-Książek A. Pericentromere clustering in Tradescantia section Rhoeo involves self-associations of AT- and GC-rich heterochromatin fractions, is developmentally regulated, and increases during differentiation. Chromosoma 2020; 129:227-242. [PMID: 32681184 PMCID: PMC7666280 DOI: 10.1007/s00412-020-00740-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 06/30/2020] [Accepted: 07/01/2020] [Indexed: 11/30/2022]
Abstract
A spectacular but poorly recognized nuclear repatterning is the association of heterochromatic domains during interphase. Using base-specific fluorescence and extended-depth-of-focus imaging, we show that the association of heterochromatic pericentromeres composed of AT- and GC-rich chromatin occurs on a large scale in cycling meiotic and somatic cells and during development in ring- and bivalent-forming Tradescantia spathacea (section Rhoeo) varieties. The mean number of pericentromere AT-rich domains per root meristem nucleus was ca. half the expected diploid number in both varieties, suggesting chromosome pairing via (peri)centromeric regions. Indeed, regular pairing of AT-rich domains was observed. The AT- and GC-rich associations in differentiated cells contributed to a significant reduction of the mean number of the corresponding foci per nucleus in relation to root meristem. Within the first 10 mm of the root, the pericentromere attraction was in progress, as if it was an active process and involved both AT- and GC-rich associations. Complying with Rabl arrangement, the pericentromeres preferentially located on one nuclear pole, clustered into diverse configurations. Among them, a strikingly regular one with 5-7 ring-arranged pericentromeric AT-rich domains may be potentially engaged in chromosome positioning during mitosis. The fluorescent pattern of pachytene meiocytes and somatic nuclei suggests the existence of a highly prescribed ring/chain type of chromocenter architecture with side-by-side arranged pericentromeric regions. The dynamics of pericentromere associations together with their non-random location within nuclei was compared with nuclear architecture in other organisms, including the widely explored Arabidopsis model.
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Affiliation(s)
- Hieronim Golczyk
- Department of Molecular Biology, Institute of Biological Sciences, John Paul II Catholic University of Lublin, Konstantynów 1i, 20-708, Lublin, Poland.
| | - Arleta Limanówka
- Department of Plant Cytology and Embryology, Institute of Botany, Jagiellonian University, Grodzka 52, 31-044, Cracow, Poland
| | - Anna Uchman-Książek
- Department of Plant Cytology and Embryology, Institute of Botany, Jagiellonian University, Grodzka 52, 31-044, Cracow, Poland
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44
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Epigenetic Factors That Control Pericentric Heterochromatin Organization in Mammals. Genes (Basel) 2020; 11:genes11060595. [PMID: 32481609 PMCID: PMC7349813 DOI: 10.3390/genes11060595] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 05/17/2020] [Accepted: 05/25/2020] [Indexed: 12/11/2022] Open
Abstract
Pericentric heterochromatin (PCH) is a particular form of constitutive heterochromatin that is localized to both sides of centromeres and that forms silent compartments enriched in repressive marks. These genomic regions contain species-specific repetitive satellite DNA that differs in terms of nucleotide sequences and repeat lengths. In spite of this sequence diversity, PCH is involved in many biological phenomena that are conserved among species, including centromere function, the preservation of genome integrity, the suppression of spurious recombination during meiosis, and the organization of genomic silent compartments in the nucleus. PCH organization and maintenance of its repressive state is tightly regulated by a plethora of factors, including enzymes (e.g., DNA methyltransferases, histone deacetylases, and histone methyltransferases), DNA and histone methylation binding factors (e.g., MECP2 and HP1), chromatin remodeling proteins (e.g., ATRX and DAXX), and non-coding RNAs. This evidence helps us to understand how PCH organization is crucial for genome integrity. It then follows that alterations to the molecular signature of PCH might contribute to the onset of many genetic pathologies and to cancer progression. Here, we describe the most recent updates on the molecular mechanisms known to underlie PCH organization and function.
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45
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GPSeq reveals the radial organization of chromatin in the cell nucleus. Nat Biotechnol 2020; 38:1184-1193. [PMID: 32451505 PMCID: PMC7610410 DOI: 10.1038/s41587-020-0519-y] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 04/09/2020] [Indexed: 12/18/2022]
Abstract
With the exception of lamina-associated domains, the radial organization of chromatin in mammalian cells remains largely unexplored. Here, we describe genomic loci positioning by sequencing (GPSeq), a genome-wide method for inferring distances to the nuclear lamina all along the nuclear radius. GPSeq relies on gradual restriction digestion of chromatin from the nuclear lamina towards the nucleus center, followed by sequencing of the generated cut sites. Using GPSeq, we mapped the radial organization of the human genome at 100 kb resolution, which revealed radial patterns of genomic and epigenomic features, gene expression, as well as A/B subcompartments. By combining radial information with chromosome contact frequencies measured by Hi-C, we substantially improved the accuracy of whole-genome structure modeling. Finally, we charted the radial topography of DNA double-strand breaks, germline variants and cancer mutations, and found that they have distinctive radial arrangements in A/B subcompartments. We conclude that GPSeq can reveal fundamental aspects of genome architecture.
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46
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Pericentromeric heterochromatin is hierarchically organized and spatially contacts H3K9me2 islands in euchromatin. PLoS Genet 2020; 16:e1008673. [PMID: 32203508 PMCID: PMC7147806 DOI: 10.1371/journal.pgen.1008673] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 04/10/2020] [Accepted: 02/14/2020] [Indexed: 01/02/2023] Open
Abstract
Membraneless pericentromeric heterochromatin (PCH) domains play vital roles in chromosome dynamics and genome stability. However, our current understanding of 3D genome organization does not include PCH domains because of technical challenges associated with repetitive sequences enriched in PCH genomic regions. We investigated the 3D architecture of Drosophila melanogaster PCH domains and their spatial associations with the euchromatic genome by developing a novel analysis method that incorporates genome-wide Hi-C reads originating from PCH DNA. Combined with cytogenetic analysis, we reveal a hierarchical organization of the PCH domains into distinct “territories.” Strikingly, H3K9me2-enriched regions embedded in the euchromatic genome show prevalent 3D interactions with the PCH domain. These spatial contacts require H3K9me2 enrichment, are likely mediated by liquid-liquid phase separation, and may influence organismal fitness. Our findings have important implications for how PCH architecture influences the function and evolution of both repetitive heterochromatin and the gene-rich euchromatin. The three dimensional (3D) organization of genomes in cell nuclei can influence a wide variety of genome functions. However, most of our understanding of this critical architecture has been limited to the gene-rich euchromatin, and largely ignores the gene-poor and repeat-rich pericentromeric heterochromatin, or PCH. PCH comprises a large part of most eukaryotic genomes, forms 3D membraneless PCH domains in nuclei, and plays a vital role in chromosome dynamics and genome stability. In this study, we developed a new method that overcomes the technical challenges imposed by the highly repetitive PCH DNA, and generated a comprehensive picture of its 3D organization. Combined with image analyses, we reveal a hierarchical organization of the PCH domains. Surprisingly, we showed that distant euchromatic regions enriched for repressive epigenetic marks also dynamically interact with the main PCH domains. These 3D interactions are likely mediated by liquid-liquid phase separation (similar to how oil and vinegar separate in salad dressing) and the resulting liquid-like fusion events, and can influence the fitness of individuals. Our discoveries have strong implications for how seemingly “junk” DNA could impact functions in the gene-rich euchromatin.
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Crosetto N, Bienko M. Radial Organization in the Mammalian Nucleus. Front Genet 2020; 11:33. [PMID: 32117447 PMCID: PMC7028756 DOI: 10.3389/fgene.2020.00033] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 01/10/2020] [Indexed: 11/13/2022] Open
Abstract
In eukaryotic cells, most of the genetic material is contained within a highly specialized organelle-the nucleus. A large body of evidence indicates that, within the nucleus, chromatinized DNA is spatially organized at multiple length scales. The higher-order organization of chromatin is crucial for proper execution of multiple genome functions, including DNA replication and transcription. Here, we review our current knowledge on the spatial organization of chromatin in the nucleus of mammalian cells, focusing in particular on how chromatin is radially arranged with respect to the nuclear lamina. We then discuss the possible mechanisms by which the radial organization of chromatin in the cell nucleus is established. Lastly, we propose a unifying model of nuclear spatial organization, and suggest novel approaches to test it.
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Affiliation(s)
| | - Magda Bienko
- Science for Life Laboratory, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
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Erenpreisa J, Giuliani A. Resolution of Complex Issues in Genome Regulation and Cancer Requires Non-Linear and Network-Based Thermodynamics. Int J Mol Sci 2019; 21:E240. [PMID: 31905791 PMCID: PMC6981914 DOI: 10.3390/ijms21010240] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 12/22/2019] [Accepted: 12/27/2019] [Indexed: 02/06/2023] Open
Abstract
The apparent lack of success in curing cancer that was evidenced in the last four decades of molecular medicine indicates the need for a global re-thinking both its nature and the biological approaches that we are taking in its solution. The reductionist, one gene/one protein method that has served us well until now, and that still dominates in biomedicine, requires complementation with a more systemic/holistic approach, to address the huge problem of cross-talk between more than 20,000 protein-coding genes, about 100,000 protein types, and the multiple layers of biological organization. In this perspective, the relationship between the chromatin network organization and gene expression regulation plays a fundamental role. The elucidation of such a relationship requires a non-linear thermodynamics approach to these biological systems. This change of perspective is a necessary step for developing successful 'tumour-reversion' therapeutic strategies.
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Affiliation(s)
- Jekaterina Erenpreisa
- Cancer Research Division, Latvian Biomedicine Research and Study Centre, LV1067 Riga, Latvia
| | - Alessandro Giuliani
- Environmental and Health Department, Istituto Superiore di Sanità, 00161 Rome, Italy;
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Kempfer R, Pombo A. Methods for mapping 3D chromosome architecture. Nat Rev Genet 2019; 21:207-226. [PMID: 31848476 DOI: 10.1038/s41576-019-0195-2] [Citation(s) in RCA: 297] [Impact Index Per Article: 59.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/04/2019] [Indexed: 12/12/2022]
Abstract
Determining how chromosomes are positioned and folded within the nucleus is critical to understanding the role of chromatin topology in gene regulation. Several methods are available for studying chromosome architecture, each with different strengths and limitations. Established imaging approaches and proximity ligation-based chromosome conformation capture (3C) techniques (such as DNA-FISH and Hi-C, respectively) have revealed the existence of chromosome territories, functional nuclear landmarks (such as splicing speckles and the nuclear lamina) and topologically associating domains. Improvements to these methods and the recent development of ligation-free approaches, including GAM, SPRITE and ChIA-Drop, are now helping to uncover new aspects of 3D genome topology that confirm the nucleus to be a complex, highly organized organelle.
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Affiliation(s)
- Rieke Kempfer
- Epigenetic Regulation and Chromatin Architecture Group, Berlin Institute for Medical Systems Biology, Max-Delbrück Centre for Molecular Medicine, Berlin, Germany. .,Institute for Biology, Humboldt University of Berlin, Berlin, Germany.
| | - Ana Pombo
- Epigenetic Regulation and Chromatin Architecture Group, Berlin Institute for Medical Systems Biology, Max-Delbrück Centre for Molecular Medicine, Berlin, Germany. .,Institute for Biology, Humboldt University of Berlin, Berlin, Germany.
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Gene-dense autosomal chromosomes show evidence for increased selection. Heredity (Edinb) 2019; 123:774-783. [PMID: 31576017 DOI: 10.1038/s41437-019-0272-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 09/16/2019] [Indexed: 12/20/2022] Open
Abstract
Purifying selection tends to reduce nucleotide and haplotype diversity leading to increased linkage disequilibrium. However, detection of evidence for selection is difficult as the signature is confounded by wide variation in the recombination rate which has a complex relationship with selection. The effective bottleneck time (the ratio of the linkage disequilibrium map to the genetic map in Morgans) controls for variability in the recombination rate. Reduced effective bottleneck times indicate stronger residual linkage disequilibrium, consistent with increased selection. Using whole genome sequence data from one European and three Sub-Saharan African human populations we find, in the African samples, strong correlations between high gene densities and reduced effective bottleneck time for autosomal chromosomes. This suggests that gene-dense autosomes have been subject to increased purifying selection reducing effective bottleneck times compared to gene-poor autosomes. Although previous studies have shown unusually strong linkage disequilibrium for the sex chromosomes variation within the autosomes has not been recognised. The strongest relationship is between effective bottleneck time and the density of essential genes, which are likely targets of greater selective pressure (p = 0.006, for the 22 autosomes). The magnitude of the reduction in chromosome-specific effective bottleneck times from the least to the most gene-dense autosomes is ~17-21% for Sub-Saharan African populations. The effect size is greater in Sub-Saharan African populations, compared to a European sample, consistent with increased efficiency of selection in populations with larger effective population sizes which have not been subject to intense population bottlenecks as experienced by populations of European ancestry. The findings highlight the value of deeper analyses of selection within Sub-Saharan African populations.
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