151
|
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.
Collapse
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
| |
Collapse
|
152
|
Abstract
We found the three-dimensional (3D) structure of chromatin at the chromosome level to be highly conserved for more than 50 million y of carnivore evolution. Intrachromosomal contacts were maintained even after chromosome rearrangements within carnivore lineages, demonstrating that the maintenance of 3D chromatin architecture is essential for conserved genome functions. These discoveries enabled the identification of orthologous chromosomal DNA segments among related species, a method we call 3D comparative scaffotyping. The method has application for putative chromosome assignment of chromosome-scale DNA sequence scaffolds produced by de novo genome sequencing. Broadly applied to biodiversity genome sequencing efforts, the approach can reduce costs associated with karyotyping and the physical mapping of DNA segments to chromosomes. High throughput chromatin conformation capture (Hi-C) of leukocyte DNA was used to investigate the evolutionary stability of chromatin conformation at the chromosomal level in 11 species from three carnivore families: Felidae, Canidae, and Ursidae. Chromosome-scale scaffolds (C-scaffolds) of each species were initially used for whole-genome alignment to a reference genome within each family. This approach established putative orthologous relationships between C-scaffolds among the different species. Hi-C contact maps for all C-scaffolds were then visually compared and found to be distinct for a given reference chromosome or C-scaffold within a species and indistinguishable for orthologous C-scaffolds having a 1:1 relationship within a family. The visual patterns within families were strongly supported by eigenvectors from the Hi-C contact maps. Analysis of Hi-C contact maps and eigenvectors across the three carnivore families revealed that most cross-family orthologous subchromosomal fragments have a conserved three-dimensional (3D) chromatin structure and thus have been under strong evolutionary constraint for ∼54 My of carnivore evolution. The most pronounced differences in chromatin conformation were observed for the X chromosome and the red fox genome, whose chromosomes have undergone extensive rearrangements relative to other canids. We also demonstrate that Hi-C contact map pattern analysis can be used to accurately identify orthologous relationships between C-scaffolds and chromosomes, a method we termed “3D comparative scaffotyping.” This method provides a powerful means for estimating karyotypes in de novo sequenced species that have unknown karyotype and no physical mapping information.
Collapse
|
153
|
Noble AJ, Purcell RV, Adams AT, Lam YK, Ring PM, Anderson JR, Osborne AJ. A Final Frontier in Environment-Genome Interactions? Integrated, Multi-Omic Approaches to Predictions of Non-Communicable Disease Risk. Front Genet 2022; 13:831866. [PMID: 35211161 PMCID: PMC8861380 DOI: 10.3389/fgene.2022.831866] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 01/19/2022] [Indexed: 12/26/2022] Open
Abstract
Epidemiological and associative research from humans and animals identifies correlations between the environment and health impacts. The environment—health inter-relationship is effected through an individual’s underlying genetic variation and mediated by mechanisms that include the changes to gene regulation that are associated with the diversity of phenotypes we exhibit. However, the causal relationships have yet to be established, in part because the associations are reduced to individual interactions and the combinatorial effects are rarely studied. This problem is exacerbated by the fact that our genomes are highly dynamic; they integrate information across multiple levels (from linear sequence, to structural organisation, to temporal variation) each of which is open to and responds to environmental influence. To unravel the complexities of the genomic basis of human disease, and in particular non-communicable diseases that are also influenced by the environment (e.g., obesity, type II diabetes, cancer, multiple sclerosis, some neurodegenerative diseases, inflammatory bowel disease, rheumatoid arthritis) it is imperative that we fully integrate multiple layers of genomic data. Here we review current progress in integrated genomic data analysis, and discuss cases where data integration would lead to significant advances in our ability to predict how the environment may impact on our health. We also outline limitations which should form the basis of future research questions. In so doing, this review will lay the foundations for future research into the impact of the environment on our health.
Collapse
Affiliation(s)
- Alexandra J Noble
- Translational Gastroenterology Unit, Nuffield Department of Experimental Medicine, University of Oxford, Oxford, United Kingdom
| | - Rachel V Purcell
- Department of Surgery, University of Otago Christchurch, Christchurch, New Zealand
| | - Alex T Adams
- Translational Gastroenterology Unit, Nuffield Department of Experimental Medicine, University of Oxford, Oxford, United Kingdom
| | - Ying K Lam
- Translational Gastroenterology Unit, Nuffield Department of Experimental Medicine, University of Oxford, Oxford, United Kingdom
| | - Paulina M Ring
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Jessica R Anderson
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Amy J Osborne
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| |
Collapse
|
154
|
Simultaneous visualization of DNA loci in single cells by combinatorial multi-color iFISH. Sci Data 2022; 9:47. [PMID: 35145120 PMCID: PMC8831585 DOI: 10.1038/s41597-022-01139-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 12/23/2021] [Indexed: 11/22/2022] Open
Abstract
Single-molecule DNA fluorescence in situ hybridization (FISH) techniques enable studying the three-dimensional (3D) organization of the genome at the single cell level. However, there is a major unmet need for open access, high quality, curated and reproducible DNA FISH datasets. Here, we describe a dataset obtained by applying our recently developed iFISH method to simultaneously visualize 16 small (size range: 62–73 kilobases, kb) DNA loci evenly spaced on chromosome 2 in human cells, in a single round of hybridization. We show how combinatorial color coding can be used to precisely localize multiple loci in 3D within single cells, and how inter-locus distances scale inversely with chromosome contact frequencies determined by high-throughput chromosome conformation capture (Hi-C). We provide raw images and 3D coordinates for nearly 10,000 FISH dots. Our dataset provides a free resource that can facilitate studies of 3D genome organization in single cells and can be used to develop automatic FISH analysis algorithms. Measurement(s) | DNA loci 3D coordinates | Technology Type(s) | Fluorescence In Situ Hybridization | Factor Type(s) | DNA FISH probe target (locus) | Sample Characteristic - Organism | Homo sapiens |
Machine-accessible metadata file describing the reported data: 10.6084/m9.figshare.17281358
Collapse
|
155
|
Abstract
Lamins interact with a host of nuclear membrane proteins, transcription factors, chromatin regulators, signaling molecules, splicing factors, and even chromatin itself to form a nuclear subcompartment, the nuclear lamina, that is involved in a variety of cellular processes such as the governance of nuclear integrity, nuclear positioning, mitosis, DNA repair, DNA replication, splicing, signaling, mechanotransduction and -sensation, transcriptional regulation, and genome organization. Lamins are the primary scaffold for this nuclear subcompartment, but interactions with lamin-associated peptides in the inner nuclear membrane are self-reinforcing and mutually required. Lamins also interact, directly and indirectly, with peripheral heterochromatin domains called lamina-associated domains (LADs) and help to regulate dynamic 3D genome organization and expression of developmentally regulated genes.
Collapse
Affiliation(s)
- Xianrong Wong
- Laboratory of Developmental and Regenerative Biology, Skin Research Institute of Singapore, Agency for Science, Technology and Research (A∗STAR), Singapore 138648
| | - Ashley J Melendez-Perez
- Department of Biological Chemistry and Center for Epigenetics, Johns Hopkins University of Medicine, Baltimore, Maryland 21205, USA
| | - Karen L Reddy
- Department of Biological Chemistry and Center for Epigenetics, Johns Hopkins University of Medicine, Baltimore, Maryland 21205, USA
- Sidney Kimmel Cancer Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland 21231, USA
| |
Collapse
|
156
|
Mammel AE, Huang HZ, Gunn AL, Choo E, Hatch EM. Chromosome length and gene density contribute to micronuclear membrane stability. Life Sci Alliance 2022; 5:e202101210. [PMID: 34789512 PMCID: PMC8605325 DOI: 10.26508/lsa.202101210] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 11/01/2021] [Accepted: 11/03/2021] [Indexed: 11/24/2022] Open
Abstract
Micronuclei are derived from missegregated chromosomes and frequently lose membrane integrity, leading to DNA damage, innate immune activation, and metastatic signaling. Here, we demonstrate that two characteristics of the trapped chromosome, length and gene density, are key contributors to micronuclei membrane stability and determine the timing of micronucleus rupture. We demonstrate that these results are not due to chromosome-specific differences in spindle position or initial protein recruitment during post-mitotic nuclear envelope assembly. Micronucleus size strongly correlates with lamin B1 levels and nuclear pore density in intact micronuclei, but, unexpectedly, lamin B1 levels do not completely predict nuclear lamina organization or membrane stability. Instead, small gene-dense micronuclei have decreased nuclear lamina gaps compared to large micronuclei, despite very low levels of lamin B1. Our data strongly suggest that nuclear envelope composition defects previously correlated with membrane rupture only partly explain membrane stability in micronuclei. We propose that an unknown factor linked to gene density has a separate function that inhibits the appearance of nuclear lamina gaps and delays membrane rupture until late in the cell cycle.
Collapse
Affiliation(s)
- Anna E Mammel
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Heather Z Huang
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Amanda L Gunn
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Emma Choo
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Emily M Hatch
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
- Human Biology Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| |
Collapse
|
157
|
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.
Collapse
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
| |
Collapse
|
158
|
Amici G, Caraglio M, Orlandini E, Micheletti C. Topological Friction and Relaxation Dynamics of Spatially Confined Catenated Polymers. ACS Macro Lett 2022; 11:1-6. [PMID: 35574798 PMCID: PMC8772382 DOI: 10.1021/acsmacrolett.1c00594] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 12/03/2021] [Indexed: 11/30/2022]
Abstract
We study catenated ring polymers confined inside channels and slits with Langevin dynamics simulations and address how the contour position and size of the interlocked or physically linked region evolve with time. We show that the catenation constraints generate a drag, or topological friction, that couples the contour motion of the interlocked regions. Notably, the coupling strength decreases as the interlocking is made tighter, but also shorter, by confinement. Though the coupling strength differs for channel and slit confinement, the data outline a single universal curve when plotted against the size of the linked region. Finally, we study how the relaxation kinetics changes after one of the rings is cut open and conclude that considering interlocked circular polymers is key for isolating the manifestations of topological friction. The results ought to be relevant for linked biomolecules in experimental or biological confining conditions.
Collapse
Affiliation(s)
- Giulia Amici
- Scuola
Internazionale Superiore di Studi Avanzati - SISSA, via Bonomea 265, 34136 Trieste, Italy
| | - Michele Caraglio
- Institut
für Theoretische Physik, Universität
Innsbruck, Technikerstraße 21A, A-6020 Innsbruck, Austria
| | - Enzo Orlandini
- Department
of Physics and Astronomy, University of
Padova, Via Marzolo 8, I-35100 Padova, Italy
| | - Cristian Micheletti
- Scuola
Internazionale Superiore di Studi Avanzati - SISSA, via Bonomea 265, 34136 Trieste, Italy
| |
Collapse
|
159
|
Cheng Q, Delafrouz P, Liang J, Liu C, Shen J. Modeling and simulation of cell nuclear architecture reorganization process. JOURNAL OF COMPUTATIONAL PHYSICS 2022; 449:110808. [PMID: 36185393 PMCID: PMC9524197 DOI: 10.1016/j.jcp.2021.110808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
We develop a special phase field/diffusive interface method to model the nuclear architecture reorganization process. In particular, we use a Lagrange multiplier approach in the phase field model to preserve the specific physical and geometrical constraints for the biological events. We develop several efficient and robust linear and weakly nonlinear schemes for this new model. To validate the model and numerical methods, we present ample numerical simulations which in particular reproduce several processes of nuclear architecture reorganization from the experiment literature.
Collapse
Affiliation(s)
- Qing Cheng
- Department of Mathematics,Purdue University, West Lafayette, IN 47907, USA
| | - Pourya Delafrouz
- Department of Bioengineering, University of Illinois at Chicago, SEO, MC-063, Chicago, IL, 60607-7052, USA
| | - Jie Liang
- Department of Bioengineering, University of Illinois at Chicago, SEO, MC-063, Chicago, IL, 60607-7052, USA
| | - Chun Liu
- Department of Applied Mathematics, Illinois Institute of Technology, Chicago, IL 60616, USA
| | - Jie Shen
- Department of Mathematics,Purdue University, West Lafayette, IN 47907, USA
| |
Collapse
|
160
|
Laghmach R, Di Pierro M, Potoyan D. A Liquid State Perspective on Dynamics of Chromatin Compartments. Front Mol Biosci 2022; 8:781981. [PMID: 35096966 PMCID: PMC8793688 DOI: 10.3389/fmolb.2021.781981] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 12/22/2021] [Indexed: 12/11/2022] Open
Abstract
The interior of the eukaryotic cell nucleus has a crowded and heterogeneous environment packed with chromatin polymers, regulatory proteins, and RNA molecules. Chromatin polymer, assisted by epigenetic modifications, protein and RNA binders, forms multi-scale compartments which help regulate genes in response to cellular signals. Furthermore, chromatin compartments are dynamic and tend to evolve in size and composition in ways that are not fully understood. The latest super-resolution imaging experiments have revealed a much more dynamic and stochastic nature of chromatin compartments than was appreciated before. An emerging mechanism explaining chromatin compartmentalization dynamics is the phase separation of protein and nucleic acids into membraneless liquid condensates. Consequently, concepts and ideas from soft matter and polymer systems have been rapidly entering the lexicon of cell biology. In this respect, the role of computational models is crucial for establishing a rigorous and quantitative foundation for the new concepts and disentangling the complex interplay of forces that contribute to the emergent patterns of chromatin dynamics and organization. Several multi-scale models have emerged to address various aspects of chromatin dynamics, ranging from equilibrium polymer simulations, hybrid non-equilibrium simulations coupling protein binding and chromatin folding, and mesoscopic field-theoretic models. Here, we review these emerging theoretical paradigms and computational models with a particular focus on chromatin’s phase separation and liquid-like properties as a basis for nuclear organization and dynamics.
Collapse
Affiliation(s)
- Rabia Laghmach
- Department of Chemistry, Iowa State University, Ames, IA, United States
| | - Michele Di Pierro
- Department of Physics, Northeastern University, Boston, MA, United States
| | - Davit Potoyan
- Department of Chemistry, Iowa State University, Ames, IA, United States
- *Correspondence: Davit Potoyan,
| |
Collapse
|
161
|
RNA gradients: Shapers of 3D genome architecture. Curr Opin Cell Biol 2022; 74:7-12. [PMID: 34998095 DOI: 10.1016/j.ceb.2021.12.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 12/01/2021] [Accepted: 12/03/2021] [Indexed: 01/13/2023]
Abstract
A growing body of evidence points to a role of nuclear RNAs (nucRNAs) in shaping the three-dimensional (3D) architecture of the genome within the nucleus of a eukaryotic cell. nucRNAs are non-homogeneously distributed within the nucleus where they can form global and local gradients that might contribute to instructing the formation and coordinating the function of different types of 3D genome structures. In this article, we highlight the available literature supporting a role of nucRNAs as 3D genome shapers and propose that nucRNA gradients are key mediators of genome structure and function.
Collapse
|
162
|
Lochs SJA, Kind J. Simultaneous Quantification of Spatial Genome Positioning and Transcriptomics in Single Cells with scDam&T-Seq. Methods Mol Biol 2022; 2532:215-241. [PMID: 35867252 DOI: 10.1007/978-1-0716-2497-5_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Spatial genome organization is considered to play an important role in mammalian cells, by guiding gene expression programs and supporting lineage specification. Yet it is still an outstanding question in the field what the direct impact of spatial genome organization on gene expression is. To elucidate this relationship further, we have recently developed scDam&T-seq, a method that simultaneously quantifies protein-DNA interactions and transcriptomes in single cells. This method efficiently combines two preexisting methods: DamID for measuring protein-DNA contacts and CEL-Seq2 for quantification of the transcriptome in single cells. scDam&T-seq has been successfully applied to measure DNA contacts with the nuclear lamina, while at the same time revealing the effect of these contacts on gene expression. This method is applicable to many different proteins of interest and can thereby aid in studying the relationship between protein-DNA interactions and gene expression in single cells.
Collapse
Affiliation(s)
- Silke J A Lochs
- Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences (KNAW), University Medical Center Utrecht, Radboud University & Oncode Institute, Utrecht, The Netherlands
| | - Jop Kind
- Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences (KNAW), University Medical Center Utrecht, Radboud University & Oncode Institute, Utrecht, The Netherlands.
| |
Collapse
|
163
|
Knoch TA. How Genomes Emerge, Function, and Evolve: Living Systems Emergence-Genotype-Phenotype-Multilism-Genome/Systems Ecology. Results Probl Cell Differ 2022; 70:103-156. [PMID: 36348106 DOI: 10.1007/978-3-031-06573-6_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
What holds together the world in its innermost, what life is, how it emerges, functions, and evolves, has not only been an epic matter of endless romantic sunset poetry and philosophy, but also manifests explicitly in its perhaps most central organization unit-genomes. Their 3D architecture and dynamics, including the interaction networks of regulatory elements, obviously co-evolved as inseparable systems allowing the physical storage, expression, and replication of genetic information. Since we were able to fill finally the much-debated centennial gaps in their 3D architecture and dynamics, now entire new perspectives open beyond epigenetics reaching as far as a general understanding of living systems: besides the previously known DNA double helix and nucleosome structure, the latter compact into a chromatin quasi-fibre folded into stable loops forming stable multi-loop aggregates/rosettes connected by linkers, creating hence the again already known chromosome arms and entire chromosomes forming the cell nucleus. Instantly and for the first time this leads now to a consistent and cross-proven systems statistical mechanics genomics framework elucidating genome intrinsic function and regulation including various components. It balances stability/flexibility ensuring genome integrity, enabling expression/regulation of genetic information, as well as genome replication/spread. Furthermore, genotype and phenotype are multiplisticly entangled being evolutionarily the outcome of both Darwinian natural selection and Lamarckian self-referenced manipulation-all embedded in even broader genome ecology (autopoietic) i(!)n- and environmental scopes. This allows formulating new meta-level functional semantics of genomics, i.e. notions as communication of genes, genomes, and information networks, architectural and dynamic spaces for creativity and innovation, or genomes as central geno-/phenotype entanglements. Beyond and most fundamentally, the paradoxical-seeming local equilibrium substance stability in its entity though far from a universal heat-death-like equilibrium is solved, and system irreversibility, time directionality, and thus the emergence of existence are clarified. Consequently, real deep understandings of genomes, life, and complex systems in general appear in evolutionary perspectives as well as from systems analyses, via system damage/disease (its repair/cure and manipulation) as far as the understanding of extraterrestrial life, the de novo creation and thus artificial life, and even the raison d'etre.
Collapse
Affiliation(s)
- Tobias A Knoch
- Biophysical Genomics, TAKnoch Joined Operations Administrative Office, Mannheim, Germany.
- Human Ecology and Complex Systems, German Society for Human Ecology (DGH), TAKnoch Joined Operations Administrative Office, Mannheim, Germany.
- TAK Renewable Energy UG, TAKnoch Joined Operations Administrative Office, Mannheim, Germany.
| |
Collapse
|
164
|
Knoch TA. Simulation of Different Three-Dimensional Models of Whole Interphase Nuclei Compared to Experiments - A Consistent Scale-Bridging Simulation Framework for Genome Organization. Results Probl Cell Differ 2022; 70:495-549. [PMID: 36348120 DOI: 10.1007/978-3-031-06573-6_18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The three-dimensional architecture of chromosomes, their arrangement, and dynamics within cell nuclei are still subject of debate. Obviously, the function of genomes-the storage, replication, and transcription of genetic information-has closely coevolved with this architecture and its dynamics, and hence are closely connected. In this work a scale-bridging framework investigates how of the 30 nm chromatin fibre organizes into chromosomes including their arrangement and morphology in the simulation of whole nuclei. Therefore, mainly two different topologies were simulated with corresponding parameter variations and comparing them to experiments: The Multi-Loop-Subcompartment (MLS) model, in which (stable) small loops form (stable) rosettes, connected by chromatin linkers, and the Random-Walk/Giant-Loop (RW/GL) model, in which large loops are attached to a flexible non-protein backbone, were simulated for various loop and linker sizes. The 30 nm chromatin fibre was modelled as a polymer chain with stretching, bending and excluded volume interactions. A spherical boundary potential simulated the confinement to nuclei with different radii. Simulated annealing and Brownian Dynamics methods were applied in a four-step decondensation procedure to generate from metaphase decondensated interphase configurations at thermodynamical equilibrium. Both the MLS and the RW/GL models form chromosome territories, with different morphologies: The MLS rosettes result in distinct subchromosomal domains visible in electron and confocal laser scanning microscopic images. In contrast, the big RW/GL loops lead to a mostly homogeneous chromatin distribution. Even small changes of the model parameters induced significant rearrangements of the chromatin morphology. The low overlap of chromosomes, arms, and subchromosomal domains observed in experiments agrees only with the MLS model. The chromatin density distribution in CLSM image stacks reveals a bimodal behaviour in agreement with recent experiments. Combination of these results with a variety of (spatial distance) measurements favour an MLS like model with loops and linkers of 63 to 126 kbp. The predicted large spaces between the chromatin fibres allow typically sized biological molecules to reach nearly every location in the nucleus by moderately obstructed diffusion and is in disagreement with the much simplified assumption that defined channels between territories for molecular transport as in the Interchromosomal Domain (ICD) hypothesis exist and are necessary for transport. All this is also in agreement with recent selective high-resolution chromosome interaction capture (T2C) experiments, the scaling behaviour of the DNA sequence, the dynamics of the chromatin fibre, the diffusion of molecules, and other measurements. Also all other chromosome topologies can in principle be excluded. In summary, polymer simulations of whole nuclei compared to experimental data not only clearly favour only a stable loop aggregate/rosette like genome architecture whose local topology is tightly connected to the global morphology and dynamics of the cell nucleus and hence can be used for understanding genome organization also in respect to diagnosis and treatment. This is in agreement with and also leads to a general novel framework of genome emergence, function, and evolution.
Collapse
Affiliation(s)
- Tobias A Knoch
- Biophysical Genomics, TAKnoch Joined Operations Administrative Office, Mannheim, Germany.
- Human Ecology and Complex Systems, German Society for Human Ecology (DGH), TAKnoch Joined Operations Administrative Office, Mannheim, Germany.
- TAK Renewable Energy UG, TAKnoch Joined Operations Administrative Office, Mannheim, Germany.
| |
Collapse
|
165
|
Maresca M, Liu NQ, de Wit E. Acute Protein Depletion Strategies to Functionally Dissect the 3D Genome. Methods Mol Biol 2022; 2532:311-331. [PMID: 35867256 DOI: 10.1007/978-1-0716-2497-5_15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The organization of the genome inside the nucleus facilitates many nuclear processes. Because the nuclear genome is highly dynamic and often regulated by essential proteins, rapid depletion strategies are necessary to perform loss-of-function analyses. Fortunately, in recent years, various methods have been developed to manipulate the cellular levels of a protein directly and acutely. Here, we describe different methods that have been developed to rapidly deplete proteins from cells, with a focus on auxin inducible degron and dTAG methods, as these are most commonly used in 3D genome organization studies. We outline best practices for designing a knockin strategy, as well as generation and validation of knockin cell lines. Acute depletion strategies have been transformative for the study of the 3D genome and will be important tools for delineating the processes and factors that determine organization of the genome inside the nucleus.
Collapse
Affiliation(s)
- Michela Maresca
- Division Gene Regulation, Oncode Institute, Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Ning Qing Liu
- Division Gene Regulation, Oncode Institute, Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Elzo de Wit
- Division Gene Regulation, Oncode Institute, Netherlands Cancer Institute, Amsterdam, The Netherlands.
| |
Collapse
|
166
|
The Physical Behavior of Interphase Chromosomes: Polymer Theory and Coarse-Grain Computer Simulations. Methods Mol Biol 2022; 2301:235-258. [PMID: 34415539 DOI: 10.1007/978-1-0716-1390-0_12] [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: 01/12/2023]
Abstract
Fluorescence in situ hybridization and chromosome conformation capture methods point to the same conclusion: that chromosomes appear to the external observer as compact structures with a highly nonrandom three-dimensional organization. In this work, we recapitulate the efforts made by us and other groups to rationalize this behavior in terms of the mathematical language and tools of polymer physics. After a brief introduction dedicated to some crucial experiments dissecting the structure of interphase chromosomes, we discuss at a nonspecialistic level some fundamental aspects of theoretical and numerical polymer physics. Then, we inglobe biological and polymer aspects into a polymer model for interphase chromosomes which moves from the observation that mutual topological constraints, such as those typically present between polymer chains in ordinary melts, induce slow chain dynamics and "constraint" chromosomes to resemble double-folded randomly branched polymer conformations. By explicitly turning these ideas into a multi-scale numerical algorithm which is described here in full details, we can design accurate model polymer conformations for interphase chromosomes and offer them for systematic comparison to experiments. The review is concluded by discussing the limitations of our approach and pointing to promising perspectives for future work.
Collapse
|
167
|
Miron E, Windo J, Ochs F, Schermelleh L. Replication Labeling Methods for Super-Resolution Imaging of Chromosome Territories and Chromatin Domains. Methods Mol Biol 2022; 2476:111-128. [PMID: 35635700 DOI: 10.1007/978-1-0716-2221-6_9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Continuing progress in super-resolution microscopy enables the study of sub-chromosomal chromatin organization in single cells with unprecedented detail. Here we describe refined methods for pulse-chase replication labeling of individual chromosome territories (CTs) and replication domain units in mammalian cell nuclei, with specific focus on their application to three-dimensional structured illumination microscopy (3D-SIM). We provide detailed protocols for highly efficient electroporation-based delivery or scratch loading of cell-impermeable fluorescent nucleotides for live-cell studies. Furthermore, we describe the application of (2'S)-2'-deoxy-2'-fluoro-5-ethynyluridine (F-ara-EdU) and 5-vinyl-2'-deoxyuridine (VdU) for the in situ detection of segregated chromosome territories and sister chromatids with minimized cytotoxic side effects.
Collapse
Affiliation(s)
- Ezequiel Miron
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Joseph Windo
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Fena Ochs
- Department of Biochemistry, University of Oxford, Oxford, UK
| | | |
Collapse
|
168
|
Conte M, Fiorillo L, Annunziatella C, Esposito A, Musella F, Abraham A, Bianco S, Chiariello AM. Dynamic and equilibrium properties of finite-size polymer models of chromosome folding. Phys Rev E 2021; 104:054402. [PMID: 34942797 DOI: 10.1103/physreve.104.054402] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 10/12/2021] [Indexed: 12/12/2022]
Abstract
Novel technologies are revealing that chromosomes have a complex three-dimensional organization within the cell nucleus that serves functional purposes. Models from polymer physics have been developed to quantitively understand the molecular principles controlling their structure and folding mechanisms. Here, by using massive molecular-dynamics simulations we show that classical scaling laws combined with finite-size effects of a simple polymer model can effectively explain the scaling behavior that chromatin exhibits at the topologically associating domains level, as revealed by experimental observations. Model results are then validated against recently published high-resolution in situ Hi-C data.
Collapse
Affiliation(s)
- Mattia Conte
- Dipartimento di Fisica, Università di Napoli Federico II, and INFN Napoli, Complesso Universitario di Monte Sant'Angelo, 80126 Naples, Italy
| | - Luca Fiorillo
- Dipartimento di Fisica, Università di Napoli Federico II, and INFN Napoli, Complesso Universitario di Monte Sant'Angelo, 80126 Naples, Italy
| | - Carlo Annunziatella
- Dipartimento di Fisica, Università di Napoli Federico II, and INFN Napoli, Complesso Universitario di Monte Sant'Angelo, 80126 Naples, Italy
| | - Andrea Esposito
- Dipartimento di Fisica, Università di Napoli Federico II, and INFN Napoli, Complesso Universitario di Monte Sant'Angelo, 80126 Naples, Italy
| | - Francesco Musella
- Dipartimento di Fisica, Università di Napoli Federico II, and INFN Napoli, Complesso Universitario di Monte Sant'Angelo, 80126 Naples, Italy
| | - Alex Abraham
- Dipartimento di Fisica, Università di Napoli Federico II, and INFN Napoli, Complesso Universitario di Monte Sant'Angelo, 80126 Naples, Italy
| | - Simona Bianco
- Berlin Institute for Medical Systems Biology, Max-Delbrück Center (MDC) for Molecular Medicine, Hannoversche Str. 28, 10115, Berlin, Germany
| | - Andrea M Chiariello
- Dipartimento di Fisica, Università di Napoli Federico II, and INFN Napoli, Complesso Universitario di Monte Sant'Angelo, 80126 Naples, Italy
| |
Collapse
|
169
|
Ubertini MA, Rosa A. Computer simulations of melts of ring polymers with nonconserved topology: A dynamic Monte Carlo lattice model. Phys Rev E 2021; 104:054503. [PMID: 34942724 DOI: 10.1103/physreve.104.054503] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 10/26/2021] [Indexed: 11/07/2022]
Abstract
We present computer simulations of a dynamic Monte Carlo algorithm for polymer chains on a fcc lattice which explicitly takes into account the possibility to overcome topological constraints by controlling the rate at which nearby polymer strands may cross through each other. By applying the method to systems of interacting ring polymers at melt conditions, we characterize their structure and dynamics by measuring, in particular, the amounts of knots and links which are formed during the relaxation process. In comparison with standard melts of unknotted and unconcatenated rings, our simulations demonstrate that the mechanism of strand crossing makes polymer dynamics faster provided the characteristic timescale of the process is smaller than the typical timescale for chain relaxation in the unperturbed state, in agreement with recent experiments employing solutions of DNA rings in the presence of the type II topoisomerase enzyme. In the opposite case of slow rates the melt is shown to become slower, and this prediction may be easily validated experimentally.
Collapse
Affiliation(s)
- Mattia Alberto Ubertini
- Scuola Internazionale Superiore di Studi Avanzati (SISSA), Via Bonomea 265, 34136 Trieste, Italy
| | - Angelo Rosa
- Scuola Internazionale Superiore di Studi Avanzati (SISSA), Via Bonomea 265, 34136 Trieste, Italy
| |
Collapse
|
170
|
Marchal C, Singh N, Corso-Díaz X, Swaroop A. HiCRes: a computational method to estimate and predict the genomic resolution of Hi-C libraries. Nucleic Acids Res 2021; 50:e35. [PMID: 34928367 DOI: 10.1093/nar/gkab1235] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 11/19/2021] [Accepted: 12/04/2021] [Indexed: 11/13/2022] Open
Abstract
Three-dimensional (3D) conformation of the chromatin is crucial to stringently regulate gene expression patterns and DNA replication in a cell-type specific manner. Hi-C is a key technique for measuring 3D chromatin interactions genome wide. Estimating and predicting the resolution of a library is an essential step in any Hi-C experimental design. Here, we present the mathematical concepts to estimate the resolution of a dataset and predict whether deeper sequencing would enhance the resolution. We have developed HiCRes, a docker pipeline, by applying these concepts to several Hi-C libraries.
Collapse
Affiliation(s)
- Claire Marchal
- Neurobiology, Neurodegeneration & Repair Laboratory, National Eye Institute, National Institutes of Health, MSC0610, 6 Center Drive, Bethesda, MD 20892, USA.,In silichrom Ltd, First Floor, Angel Court, 81 St Clements St, Oxford OX4 1AW, UK
| | - Nivedita Singh
- Neurobiology, Neurodegeneration & Repair Laboratory, National Eye Institute, National Institutes of Health, MSC0610, 6 Center Drive, Bethesda, MD 20892, USA
| | - Ximena Corso-Díaz
- Neurobiology, Neurodegeneration & Repair Laboratory, National Eye Institute, National Institutes of Health, MSC0610, 6 Center Drive, Bethesda, MD 20892, USA
| | - Anand Swaroop
- Neurobiology, Neurodegeneration & Repair Laboratory, National Eye Institute, National Institutes of Health, MSC0610, 6 Center Drive, Bethesda, MD 20892, USA
| |
Collapse
|
171
|
Cardozo Gizzi AM. A Shift in Paradigms: Spatial Genomics Approaches to Reveal Single-Cell Principles of Genome Organization. Front Genet 2021; 12:780822. [PMID: 34868269 PMCID: PMC8640135 DOI: 10.3389/fgene.2021.780822] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 11/03/2021] [Indexed: 12/12/2022] Open
Abstract
The genome tridimensional (3D) organization and its role towards the regulation of key cell processes such as transcription is currently a main question in biology. Interphase chromosomes are spatially segregated into "territories," epigenetically-defined large domains of chromatin that interact to form "compartments" with common transcriptional status, and insulator-flanked domains called "topologically associating domains" (TADs). Moreover, chromatin organizes around nuclear structures such as lamina, speckles, or the nucleolus to acquire a higher-order genome organization. Due to recent technological advances, the different hierarchies are being solved. Particularly, advances in microscopy technologies are shedding light on the genome structure at multiple levels. Intriguingly, more and more reports point to high variability and stochasticity at the single-cell level. However, the functional consequences of such variability in genome conformation are still unsolved. Here, I will discuss the implication of the cell-to-cell heterogeneity at the different scales in the context of newly developed imaging approaches, particularly multiplexed Fluorescence in situ hybridization methods that enabled "chromatin tracing." Extensions of these methods are now combining spatial information of dozens to thousands of genomic loci with the localization of nuclear features such as the nucleolus, nuclear speckles, or even histone modifications, creating the fast-moving field of "spatial genomics." As our view of genome organization shifts the focus from ensemble to single-cell, new insights to fundamental questions begin to emerge.
Collapse
Affiliation(s)
- Andres M Cardozo Gizzi
- Centro de Investigación en Medicina Traslacional Severo Amuchastegui (CIMETSA), Instituto Universitario de Ciencias Biomédicas de Córdoba (IUCBC), CONICET, Córdoba, Argentina
| |
Collapse
|
172
|
Hirata Y, Kitanishi Y, Sugishita H, Gotoh Y. Fast reconstruction of an original continuous series from a recurrence plot. CHAOS (WOODBURY, N.Y.) 2021; 31:121101. [PMID: 34972333 DOI: 10.1063/5.0073899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Accepted: 11/18/2021] [Indexed: 06/14/2023]
Abstract
We propose an algorithm to refine the reconstruction of an original time series given a recurrence plot, which is also referred to as a contact map. The refinement process calculates the local distances based on the Jaccard coefficients with the neighbors in the previous resolution for each point and takes their weighted average using local distances. We demonstrate the utility of our method using two examples.
Collapse
Affiliation(s)
- Yoshito Hirata
- Faculty of Engineering, Information and Systems, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573, Japan
| | - Yuki Kitanishi
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Hiroki Sugishita
- International Research Center for Neurointelligence (WPI-IRCN), The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Yukiko Gotoh
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0032, Japan
| |
Collapse
|
173
|
Di Stefano M, Nützmann HW. Modeling the 3D genome of plants. Nucleus 2021; 12:65-81. [PMID: 34057011 PMCID: PMC8168717 DOI: 10.1080/19491034.2021.1927503] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 04/29/2021] [Accepted: 05/05/2021] [Indexed: 12/11/2022] Open
Abstract
Chromosomes are the carriers of inheritable traits and define cell function and development. This is not only based on the linear DNA sequence of chromosomes but also on the additional molecular information they are associated with, including the transcription machinery, histone modifications, and their three-dimensional folding. The synergistic application of experimental approaches and computer simulations has helped to unveil how these organizational layers of the genome interplay in various organisms. However, such multidisciplinary approaches are still rarely explored in the plant kingdom. Here, we provide an overview of our current knowledge on plant 3D genome organization and review recent efforts to integrate cutting-edge experiments from microscopy and next-generation sequencing approaches with theoretical models. Building on these recent approaches, we propose possible avenues to extend the application of theoretical modeling in the characterization of the 3D genome organization in plants.
Collapse
Affiliation(s)
- Marco Di Stefano
- Institute of Human Genetics, Centre National de la Recherche Scientifique, University of Montpellier, Montpellier, France
| | - Hans-Wilhelm Nützmann
- The Milner Centre for Evolution, Department of Biology and Biochemistry, University of Bath, Bath, UK
| |
Collapse
|
174
|
Chiang M, Brackley CA, Marenduzzo D, Gilbert N. Predicting genome organisation and function with mechanistic modelling. Trends Genet 2021; 38:364-378. [PMID: 34857425 DOI: 10.1016/j.tig.2021.11.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 10/11/2021] [Accepted: 11/01/2021] [Indexed: 12/14/2022]
Abstract
Fitting-free mechanistic models based on polymer simulations predict chromatin folding in 3D by focussing on the underlying biophysical mechanisms. This class of models has been increasingly used in conjunction with experiments to study the spatial organisation of eukaryotic chromosomes. Feedback from experiments to models leads to successive model refinement and has previously led to the discovery of new principles for genome organisation. Here, we review the basis of mechanistic polymer simulations, explain some of the more recent approaches and the contexts in which they have been useful to explain chromosome biology, and speculate on how they might be used in the future.
Collapse
Affiliation(s)
- Michael Chiang
- SUPA, School of Physics and Astronomy, University of Edinburgh, Peter Guthrie Tait Road, Edinburgh, EH9 3FD, UK
| | - Chris A Brackley
- SUPA, School of Physics and Astronomy, University of Edinburgh, Peter Guthrie Tait Road, Edinburgh, EH9 3FD, UK
| | - Davide Marenduzzo
- SUPA, School of Physics and Astronomy, University of Edinburgh, Peter Guthrie Tait Road, Edinburgh, EH9 3FD, UK
| | - Nick Gilbert
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Western General Hospital, Crewe Road South, Edinburgh, EH4 2XU, UK.
| |
Collapse
|
175
|
Choi JH, Kwon T, Sung BJ. Relative Chain Flexibility Determines the Spatial Arrangement and the Diffusion of a Single Ring Chain in Linear Chain Films. Macromolecules 2021. [DOI: 10.1021/acs.macromol.1c01937] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- Jong Ho Choi
- Department of Chemistry, Sogang University, Seoul 04107, Republic of Korea
| | - Taejin Kwon
- Department of Chemistry, Sogang University, Seoul 04107, Republic of Korea
| | - Bong June Sung
- Department of Chemistry, Sogang University, Seoul 04107, Republic of Korea
| |
Collapse
|
176
|
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: 2] [Impact Index Per Article: 0.7] [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.
Collapse
|
177
|
Wakim JG, Sandholtz SH, Spakowitz AJ. Impact of chromosomal organization on epigenetic drift and domain stability revealed by physics-based simulations. Biophys J 2021; 120:4932-4943. [PMID: 34687722 DOI: 10.1016/j.bpj.2021.10.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 09/07/2021] [Accepted: 10/18/2021] [Indexed: 12/21/2022] Open
Abstract
We examine the relationship between the size of domains of epigenetic marks and the stability of those domains using our theoretical model that captures the physical mechanisms governing the maintenance of epigenetic modifications. We focus our study on histone H3 lysine-9 trimethylation, one of the most common and consequential epigenetic marks with roles in chromatin compaction and gene repression. Our model combines the effects of methyl spreading by methyltransferases and chromatin segregation into heterochromatin and euchromatin because of preferential heterochromatin protein 1 (HP1) binding. Our model indicates that, although large methylated domains are passed successfully from one chromatin generation to the next, small alterations to the methylation sequence are not maintained during chromatin replication. Using our predictive model, we investigate the size required for an epigenetic domain to persist over chromatin generations while surrounded by a much larger domain of opposite methylation and compaction state. We find that there is a critical size threshold in the hundreds-of-nucleosomes scale above which an epigenetic domain will be reliably maintained over generations. The precise size of the threshold differs for heterochromatic and euchromatic domains. Our results are consistent with natural alterations to the epigenetic sequence occurring during embryonic development and due to age-related epigenetic drift.
Collapse
Affiliation(s)
- Joseph G Wakim
- Department of Chemical Engineering, Stanford University, Stanford, California
| | | | - Andrew J Spakowitz
- Department of Chemical Engineering, Stanford University, Stanford, California; Department of Materials Science and Engineering, Stanford University, Stanford, California; Biophysics Program, Stanford University, Stanford, California; Department of Applied Physics, Stanford University, Stanford, California.
| |
Collapse
|
178
|
Roca J, Dyson S, Segura J, Valdés A, Martínez-García B. Keeping intracellular DNA untangled: A new role for condensin? Bioessays 2021; 44:e2100187. [PMID: 34761394 DOI: 10.1002/bies.202100187] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 10/25/2021] [Accepted: 10/26/2021] [Indexed: 12/25/2022]
Abstract
The DNA-passage activity of topoisomerase II accidentally produces DNA knots and interlinks within and between chromatin fibers. Fortunately, these unwanted DNA entanglements are actively removed by some mechanism. Here we present an outline on DNA knot formation and discuss recent studies that have investigated how intracellular DNA knots are removed. First, although topoisomerase II is able to minimize DNA entanglements in vitro to below equilibrium values, it is unclear whether such capacity performs equally in vivo in chromatinized DNA. Second, DNA supercoiling could bias topoisomerase II to untangle the DNA. However, experimental evidence indicates that transcriptional supercoiling of intracellular DNA boosts knot formation. Last, cohesin and condensin could tighten DNA entanglements via DNA loop extrusion (LE) and force their dissolution by topoisomerase II. Recent observations indicate that condensin activity promotes the removal of DNA knots during interphase and mitosis. This activity might facilitate the spatial organization and dynamics of chromatin.
Collapse
Affiliation(s)
- Joaquim Roca
- Molecular Biology Institute of Barcelona (IBMB), Spanish National Research Council (CSIC), Barcelona, Spain
| | - Silvia Dyson
- Molecular Biology Institute of Barcelona (IBMB), Spanish National Research Council (CSIC), Barcelona, Spain
| | - Joana Segura
- Molecular Biology Institute of Barcelona (IBMB), Spanish National Research Council (CSIC), Barcelona, Spain
| | - Antonio Valdés
- Julius Maximilian University of Würzburg, Würzburg, Germany
| | - Belén Martínez-García
- Molecular Biology Institute of Barcelona (IBMB), Spanish National Research Council (CSIC), Barcelona, Spain
| |
Collapse
|
179
|
Waters PD, Patel HR, Ruiz-Herrera A, Álvarez-González L, Lister NC, Simakov O, Ezaz T, Kaur P, Frere C, Grützner F, Georges A, Graves JAM. Microchromosomes are building blocks of bird, reptile, and mammal chromosomes. Proc Natl Acad Sci U S A 2021; 118:e2112494118. [PMID: 34725164 PMCID: PMC8609325 DOI: 10.1073/pnas.2112494118] [Citation(s) in RCA: 63] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/09/2021] [Indexed: 12/11/2022] Open
Abstract
Microchromosomes, once considered unimportant shreds of the chicken genome, are gene-rich elements with a high GC content and few transposable elements. Their origin has been debated for decades. We used cytological and whole-genome sequence comparisons, and chromosome conformation capture, to trace their origin and fate in genomes of reptiles, birds, and mammals. We find that microchromosomes as well as macrochromosomes are highly conserved across birds and share synteny with single small chromosomes of the chordate amphioxus, attesting to their origin as elements of an ancient animal genome. Turtles and squamates (snakes and lizards) share different subsets of ancestral microchromosomes, having independently lost microchromosomes by fusion with other microchromosomes or macrochromosomes. Patterns of fusions were quite different in different lineages. Cytological observations show that microchromosomes in all lineages are spatially separated into a central compartment at interphase and during mitosis and meiosis. This reflects higher interaction between microchromosomes than with macrochromosomes, as observed by chromosome conformation capture, and suggests some functional coherence. In highly rearranged genomes fused microchromosomes retain most ancestral characteristics, but these may erode over evolutionary time; surprisingly, de novo microchromosomes have rapidly adopted high interaction. Some chromosomes of early-branching monotreme mammals align to several bird microchromosomes, suggesting multiple microchromosome fusions in a mammalian ancestor. Subsequently, multiple rearrangements fueled the extraordinary karyotypic diversity of therian mammals. Thus, microchromosomes, far from being aberrant genetic elements, represent fundamental building blocks of amniote chromosomes, and it is mammals, rather than reptiles and birds, that are atypical.
Collapse
Affiliation(s)
- Paul D Waters
- School of Biotechnology and Biomolecular Science, Faculty of Science, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Hardip R Patel
- The John Curtin School of Medical Research, Australian National University, Canberra, ACT 2601, Australia
| | - Aurora Ruiz-Herrera
- Departament de Biologia Cel·lular, Fisiologia i Immunologia, Universitat Autònoma de Barcelona, Cerdanyola del Vallès 08193, Spain
- Genome Integrity and Instability Group, Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Cerdanyola del Vallès 08193, Spain
| | - Lucía Álvarez-González
- Departament de Biologia Cel·lular, Fisiologia i Immunologia, Universitat Autònoma de Barcelona, Cerdanyola del Vallès 08193, Spain
- Genome Integrity and Instability Group, Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Cerdanyola del Vallès 08193, Spain
| | - Nicholas C Lister
- School of Biotechnology and Biomolecular Science, Faculty of Science, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Oleg Simakov
- Department of Neurosciences and Developmental Biology, University of Vienna, 1010 Vienna, Austria
| | - Tariq Ezaz
- Institute for Applied Ecology, University of Canberra, Canberra, ACT 2601, Australia
| | - Parwinder Kaur
- UWA School of Agriculture and Environment, The University of Western Australia, Crawley, WA 6009, Australia
| | - Celine Frere
- Global Change Ecology Research Group, University of the Sunshine Coast, Sippy Downs, QLD 4556, Australia
| | - Frank Grützner
- School of Biological Sciences, University of Adelaide, Adelaide, SA 5000, Australia
| | - Arthur Georges
- Institute for Applied Ecology, University of Canberra, Canberra, ACT 2601, Australia
| | - Jennifer A Marshall Graves
- Institute for Applied Ecology, University of Canberra, Canberra, ACT 2601, Australia;
- School of Life Sciences, La Trobe University, Bundoora, VIC 3068, Australia
| |
Collapse
|
180
|
Park TL, Lee Y, Cho WK. Visualization of chromatin higher-order structures and dynamics in live cells. BMB Rep 2021. [PMID: 34488934 PMCID: PMC8560465 DOI: 10.5483/bmbrep.2021.54.10.098] [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] [Indexed: 11/20/2022] Open
Abstract
Chromatin has highly organized structures in the nucleus, and these higher-order structures are proposed to regulate gene activities and cellular processes. Sequencing-based techniques, such as Hi-C, and fluorescent in situ hybridization (FISH) have revealed a spatial segregation of active and inactive compartments of chromatin, as well as the non-random positioning of chromosomes in the nucleus, respectively. However, regardless of their efficiency in capturing target genomic sites, these techniques are limited to fixed cells. Since chromatin has dynamic structures, live cell imaging techniques are highlighted for their ability to detect conformational changes in chromatin at a specific time point, or to track various arrangements of chromatin through long-term imaging. Given that the imaging approaches to study live cells are dramatically advanced, we recapitulate methods that are widely used to visualize the dynamics of higher-order chromatin structures.
Collapse
Affiliation(s)
- Tae Lim Park
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - YigJi Lee
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Won-Ki Cho
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
- KI for Health Science and Technology (KIHST), Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| |
Collapse
|
181
|
Hansen JC, Maeshima K, Hendzel MJ. The solid and liquid states of chromatin. Epigenetics Chromatin 2021; 14:50. [PMID: 34717733 PMCID: PMC8557566 DOI: 10.1186/s13072-021-00424-5] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 10/22/2021] [Indexed: 12/14/2022] Open
Abstract
The review begins with a concise description of the principles of phase separation. This is followed by a comprehensive section on phase separation of chromatin, in which we recount the 60 years history of chromatin aggregation studies, discuss the evidence that chromatin aggregation intrinsically is a physiologically relevant liquid-solid phase separation (LSPS) process driven by chromatin self-interaction, and highlight the recent findings that under specific solution conditions chromatin can undergo liquid-liquid phase separation (LLPS) rather than LSPS. In the next section of the review, we discuss how certain chromatin-associated proteins undergo LLPS in vitro and in vivo. Some chromatin-binding proteins undergo LLPS in purified form in near-physiological ionic strength buffers while others will do so only in the presence of DNA, nucleosomes, or chromatin. The final section of the review evaluates the solid and liquid states of chromatin in the nucleus. While chromatin behaves as an immobile solid on the mesoscale, nucleosomes are mobile on the nanoscale. We discuss how this dual nature of chromatin, which fits well the concept of viscoelasticity, contributes to genome structure, emphasizing the dominant role of chromatin self-interaction.
Collapse
Affiliation(s)
- Jeffrey C Hansen
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, 80523, USA.
| | - Kazuhiro Maeshima
- Genome Dynamics Laboratory, National Institute of Genetics, and Department of Genetics, Sokendai (Graduate University for Advanced Studies), Mishima, Shizuoka, 411-8540, Japan.
| | - Michael J Hendzel
- Department of Cell Biology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada.
- Department of Oncology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada.
| |
Collapse
|
182
|
Marti-Marimon M, Vialaneix N, Lahbib-Mansais Y, Zytnicki M, Camut S, Robelin D, Yerle-Bouissou M, Foissac S. Major Reorganization of Chromosome Conformation During Muscle Development in Pig. Front Genet 2021; 12:748239. [PMID: 34675966 PMCID: PMC8523936 DOI: 10.3389/fgene.2021.748239] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 09/14/2021] [Indexed: 12/12/2022] Open
Abstract
The spatial organization of the genome in the nucleus plays a crucial role in eukaryotic cell functions, yet little is known about chromatin structure variations during late fetal development in mammals. We performed in situ high-throughput chromosome conformation capture (Hi-C) sequencing of DNA from muscle samples of pig fetuses at two late stages of gestation. Comparative analysis of the resulting Hi-C interaction matrices between both groups showed widespread differences of different types. First, we discovered a complex landscape of stable and group-specific Topologically Associating Domains (TADs). Investigating the nuclear partition of the chromatin into transcriptionally active and inactive compartments, we observed a genome-wide fragmentation of these compartments between 90 and 110 days of gestation. Also, we identified and characterized the distribution of differential cis- and trans-pairwise interactions. In particular, trans-interactions at chromosome extremities revealed a mechanism of telomere clustering further confirmed by 3D Fluorescence in situ Hybridization (FISH). Altogether, we report major variations of the three-dimensional genome conformation during muscle development in pig, involving several levels of chromatin remodeling and structural regulation.
Collapse
Affiliation(s)
| | | | | | | | - Sylvie Camut
- GenPhySE, Université de Toulouse, INRAE, ENVT, Castanet Tolosan, France
| | - David Robelin
- GenPhySE, Université de Toulouse, INRAE, ENVT, Castanet Tolosan, France
| | | | - Sylvain Foissac
- GenPhySE, Université de Toulouse, INRAE, ENVT, Castanet Tolosan, France
| |
Collapse
|
183
|
Four-dimensional chromosome reconstruction elucidates the spatiotemporal reorganization of the mammalian X chromosome. Proc Natl Acad Sci U S A 2021; 118:2107092118. [PMID: 34645712 DOI: 10.1073/pnas.2107092118] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/27/2021] [Indexed: 12/14/2022] Open
Abstract
Chromosomes are segmented into domains and compartments, but how these structures are spatially related in three dimensions (3D) is unclear. Here, we developed tools that directly extract 3D information from Hi-C experiments and integrate the data across time. With our "4DHiC" method, we use X chromosome inactivation (XCI) as a model to examine the time evolution of 3D chromosome architecture during large-scale changes in gene expression. Our modeling resulted in several insights. Both A/B and S1/S2 compartments divide the X chromosome into hemisphere-like structures suggestive of a spatial phase-separation. During the XCI, the X chromosome transits through A/B, S1/S2, and megadomain structures by undergoing only partial mixing to assume new structures. Interestingly, when an active X chromosome (Xa) is reorganized into an inactive X chromosome (Xi), original underlying compartment structures are not fully eliminated within the Xi superstructure. Our study affirms slow mixing dynamics in the inner chromosome core and faster dynamics near the surface where escapees reside. Once established, the Xa and Xi resemble glassy polymers where mixing no longer occurs. Finally, Xist RNA molecules initially reside within the A compartment but transition to the interface between the A and B hemispheres and then spread between hemispheres via both surface and core to establish the Xi.
Collapse
|
184
|
Park TL, Lee Y, Cho WK. Visualization of chromatin higher-order structures and dynamics in live cells. BMB Rep 2021; 54:489-496. [PMID: 34488934 PMCID: PMC8560465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 08/09/2021] [Accepted: 08/29/2021] [Indexed: 04/05/2024] Open
Abstract
Chromatin has highly organized structures in the nucleus, and these higher-order structures are proposed to regulate gene activities and cellular processes. Sequencing-based techniques, such as Hi-C, and fluorescent in situ hybridization (FISH) have revealed a spatial segregation of active and inactive compartments of chromatin, as well as the non-random positioning of chromosomes in the nucleus, respectively. However, regardless of their efficiency in capturing target genomic sites, these techniques are limited to fixed cells. Since chromatin has dynamic structures, live cell imaging techniques are highlighted for their ability to detect conformational changes in chromatin at a specific time point, or to track various arrangements of chromatin through long-term imaging. Given that the imaging approaches to study live cells are dramatically advanced, we recapitulate methods that are widely used to visualize the dynamics of higher-order chromatin structures. [BMB Reports 2021; 54(10): 489-496].
Collapse
Affiliation(s)
- Tae Lim Park
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - YigJi Lee
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Won-Ki Cho
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
- KI for Health Science and Technology (KIHST), Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| |
Collapse
|
185
|
Chaudhary N, Im JK, Nho SH, Kim H. Visualizing Live Chromatin Dynamics through CRISPR-Based Imaging Techniques. Mol Cells 2021; 44:627-636. [PMID: 34588320 PMCID: PMC8490199 DOI: 10.14348/molcells.2021.2254] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2020] [Revised: 08/25/2021] [Accepted: 08/26/2021] [Indexed: 11/27/2022] Open
Abstract
The three-dimensional organization of chromatin and its time-dependent changes greatly affect virtually every cellular function, especially DNA replication, genome maintenance, transcription regulation, and cell differentiation. Sequencing-based techniques such as ChIP-seq, ATAC-seq, and Hi-C provide abundant information on how genomic elements are coupled with regulatory proteins and functionally organized into hierarchical domains through their interactions. However, visualizing the time-dependent changes of such organization in individual cells remains challenging. Recent developments of CRISPR systems for site-specific fluorescent labeling of genomic loci have provided promising strategies for visualizing chromatin dynamics in live cells. However, there are several limiting factors, including background signals, off-target binding of CRISPR, and rapid photobleaching of the fluorophores, requiring a large number of target-bound CRISPR complexes to reliably distinguish the target-specific foci from the background. Various modifications have been engineered into the CRISPR system to enhance the signal-to-background ratio and signal longevity to detect target foci more reliably and efficiently, and to reduce the required target size. In this review, we comprehensively compare the performances of recently developed CRISPR designs for improved visualization of genomic loci in terms of the reliability of target detection, the ability to detect small repeat loci, and the allowed time of live tracking. Longer observation of genomic loci allows the detailed identification of the dynamic characteristics of chromatin. The diffusion properties of chromatin found in recent studies are reviewed, which provide suggestions for the underlying biological processes.
Collapse
Affiliation(s)
- Narendra Chaudhary
- Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919, Korea
| | - Jae-Kyeong Im
- Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919, Korea
| | - Si-Hyeong Nho
- Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919, Korea
| | - Hajin Kim
- Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919, Korea
| |
Collapse
|
186
|
Gene Amplification and the Extrachromosomal Circular DNA. Genes (Basel) 2021; 12:genes12101533. [PMID: 34680928 PMCID: PMC8535887 DOI: 10.3390/genes12101533] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2021] [Revised: 09/09/2021] [Accepted: 09/23/2021] [Indexed: 12/12/2022] Open
Abstract
Oncogene amplification is closely linked to the pathogenesis of a broad spectrum of human malignant tumors. The amplified genes localize either to the extrachromosomal circular DNA, which has been referred to as cytogenetically visible double minutes (DMs), or submicroscopic episome, or to the chromosomal homogeneously staining region (HSR). The extrachromosomal circle from a chromosome arm can initiate gene amplification, resulting in the formation of DMs or HSR, if it had a sequence element required for replication initiation (the replication initiation region/matrix attachment region; the IR/MAR), under a genetic background that permits gene amplification. In this article, the nature, intracellular behavior, generation, and contribution to cancer genome plasticity of such extrachromosomal circles are summarized and discussed by reviewing recent articles on these topics. Such studies are critical in the understanding and treating human cancer, and also for the production of recombinant proteins such as biopharmaceuticals by increasing the recombinant genes in the cells.
Collapse
|
187
|
Takatsuka H, Shibata A, Umeda M. Genome Maintenance Mechanisms at the Chromatin Level. Int J Mol Sci 2021; 22:ijms221910384. [PMID: 34638727 PMCID: PMC8508675 DOI: 10.3390/ijms221910384] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 09/22/2021] [Accepted: 09/24/2021] [Indexed: 12/12/2022] Open
Abstract
Genome integrity is constantly threatened by internal and external stressors, in both animals and plants. As plants are sessile, a variety of environment stressors can damage their DNA. In the nucleus, DNA twines around histone proteins to form the higher-order structure “chromatin”. Unraveling how chromatin transforms on sensing genotoxic stress is, thus, key to understanding plant strategies to cope with fluctuating environments. In recent years, accumulating evidence in plant research has suggested that chromatin plays a crucial role in protecting DNA from genotoxic stress in three ways: (1) changes in chromatin modifications around damaged sites enhance DNA repair by providing a scaffold and/or easy access to DNA repair machinery; (2) DNA damage triggers genome-wide alterations in chromatin modifications, globally modulating gene expression required for DNA damage response, such as stem cell death, cell-cycle arrest, and an early onset of endoreplication; and (3) condensed chromatin functions as a physical barrier against genotoxic stressors to protect DNA. In this review, we highlight the chromatin-level control of genome stability and compare the regulatory systems in plants and animals to find out unique mechanisms maintaining genome integrity under genotoxic stress.
Collapse
Affiliation(s)
- Hirotomo Takatsuka
- School of Biological Science and Technology, College of Science and Engineering, Kanazawa University, Kakuma-Machi, Kanazawa 920-1192, Japan;
| | - Atsushi Shibata
- Signal Transduction Program, Gunma University Initiative for Advanced Research (GIAR), 3-39-22, Showa-Machi, Maebashi 371-8511, Japan;
| | - Masaaki Umeda
- Graduate School of Science and Technology, Nara Institute of Science and Technology, Ikoma 630-0192, Japan
- Correspondence:
| |
Collapse
|
188
|
Shiimori M, Nukiwa R, Imai Y. Dynamics of the host chromatin three-dimensional response to influenza virus infection. Int Immunol 2021; 33:541-545. [PMID: 34282455 DOI: 10.1093/intimm/dxab043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 07/19/2021] [Indexed: 11/14/2022] Open
Abstract
The spatial organization of chromatin is known to be highly dynamic in response to environmental stress. However, it remains unknown how chromatin dynamics contributes to or modulates the pathogenesis of immune and infectious diseases. Influenza virus is a single-stranded RNA virus, and transcription and replication of the virus genome occur in the nucleus. Since viral infection is generally associated with virus-driven hijack of the host cellular machineries, influenza virus may utilize and/or affect the nuclear system. In this review article, we focus on recent studies showing that the three-dimensional structure of chromatin changes with influenza virus infection, which affects the pathology of infection. Also, we discuss studies showing the roles of epigenetics in influenza virus infection. Understanding how this affects immune responses may lead to novel strategies to combat immune and infectious diseases.
Collapse
Affiliation(s)
- Masami Shiimori
- Laboratory of Regulation for Intractable Infectious Diseases, National Institutes of Biomedical Innovation, Health and Nutrition (NIBIOHN), Osaka 567-0085, Japan
| | - Ryota Nukiwa
- Laboratory of Regulation for Intractable Infectious Diseases, National Institutes of Biomedical Innovation, Health and Nutrition (NIBIOHN), Osaka 567-0085, Japan
| | - Yumiko Imai
- Laboratory of Regulation for Intractable Infectious Diseases, National Institutes of Biomedical Innovation, Health and Nutrition (NIBIOHN), Osaka 567-0085, Japan
- Laboratory for Infectious Systems, Institute for Protein Research, Osaka University, Osaka 565-0871, Japan
| |
Collapse
|
189
|
Doughty TW, Yu R, Chao LFI, Qin Z, Siewers V, Nielsen J. A single chromosome strain of S. cerevisiae exhibits diminished ethanol metabolism and tolerance. BMC Genomics 2021; 22:688. [PMID: 34551706 PMCID: PMC8456624 DOI: 10.1186/s12864-021-07947-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 08/25/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Eukaryotic organisms, like the model yeast S. cerevisiae, have linear chromosomes that facilitate organization and protection of nuclear DNA. A recent work described a stepwise break/repair method that enabled fusion of the 16 chromosomes of S. cerevisiae into a single large chromosome. Construction of this strain resulted in the removal of 30 of 32 telomeres, over 300 kb of subtelomeric DNA, and 107 subtelomeric ORFs. Despite these changes, characterization of the single chromosome strain uncovered modest phenotypes compared to a reference strain. RESULTS This study further characterized the single chromosome strain and found that it exhibited a longer lag phase, increased doubling time, and lower final biomass concentration compared with a reference strain when grown on YPD. These phenotypes were amplified when ethanol was added to the medium or used as the sole carbon source. RNAseq analysis showed poor induction of genes involved in diauxic shift, ethanol metabolism, and fatty-acid ß-oxidation during growth on ethanol compared to the reference strain. Enzyme-constrained metabolic modeling identified decreased flux through the enzymes that are encoded by these poorly induced genes as a likely cause of diminished biomass accumulation. The diminished growth on ethanol for the single chromosome strain was rescued by nicotinamide, an inhibitor of sirtuin family deacetylases, which have been shown to silence gene expression in heterochromatic regions. CONCLUSIONS Our results indicate that sirtuin-mediated silencing in the single chromosome strain interferes with growth on non-fermentable carbon sources. We propose that the removal of subtelomeric DNA that would otherwise be bound by sirtuins leads to silencing at other loci in the single chromosome strain. Further, we hypothesize that the poorly induced genes in the single chromosome strain during ethanol growth could be silenced by sirtuins in wildtype S. cerevisiae during growth on glucose.
Collapse
Affiliation(s)
- Tyler W Doughty
- Department of Biology and Biological Engineering, Chalmers University of Technology, SE-412 96, Gothenburg, Sweden
- Novo Nordisk Foundation Center for Biosustainability, Chalmers University of Technology, SE-412 96, Gothenburg, Sweden
| | - Rosemary Yu
- Department of Biology and Biological Engineering, Chalmers University of Technology, SE-412 96, Gothenburg, Sweden
- Novo Nordisk Foundation Center for Biosustainability, Chalmers University of Technology, SE-412 96, Gothenburg, Sweden
| | - Lucy Fang-I Chao
- Department of Biology and Biological Engineering, Chalmers University of Technology, SE-412 96, Gothenburg, Sweden
- Novo Nordisk Foundation Center for Biosustainability, Chalmers University of Technology, SE-412 96, Gothenburg, Sweden
| | - Zhongjun Qin
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Verena Siewers
- Department of Biology and Biological Engineering, Chalmers University of Technology, SE-412 96, Gothenburg, Sweden
- Novo Nordisk Foundation Center for Biosustainability, Chalmers University of Technology, SE-412 96, Gothenburg, Sweden
| | - Jens Nielsen
- Department of Biology and Biological Engineering, Chalmers University of Technology, SE-412 96, Gothenburg, Sweden.
- Novo Nordisk Foundation Center for Biosustainability, Chalmers University of Technology, SE-412 96, Gothenburg, Sweden.
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, DK-2800, Kongens Lyngby, Denmark.
- BioInnovation Institute, DK-2200, Copenhagen N, Denmark.
| |
Collapse
|
190
|
Liao X, Guo S, Yin X, Liao B, Li M, Su H, Li Q, Pei J, Gao J, Lei J, Li X, Huang Z, Xu J, Chen S. Hierarchical chromatin features reveal the toxin production in Bungarus multicinctus. Chin Med 2021; 16:90. [PMID: 34535171 PMCID: PMC8447776 DOI: 10.1186/s13020-021-00502-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 09/04/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Bungarus multicinctus, from which a classical Chinese medicine is produced, is known as the most venomous land snake in the world, but the chromatin organization and transcription factor activity during venom replenishment progress have not been explored yet. This study aimed to determine the roles of chromatin structure in toxin activity via bioinformatics and experimental validation. METHODS Chromosome conformation capture (Hi-C) analysis was used to examine interactions among chromosomes and identify different scales of chromatin during envenomation in B. multicinctus. Correlations between epigenetic modifications and chromatin structure were verified through ChIP-seq analysis. RNA-seq was used to validate the influence of variation in chromatin structure and gene expression levels on venom production and regulation. RESULTS Our results suggested that intra-chromosomal interactions are more intense than inter-chromosomal interactions among the control group, 3-day group of venom glands and muscles. Through this, we found that compartmental transition was correlated with chromatin interactions. Interestingly, the up-regulated genes in more compartmental switch regions reflect the function of toxin activity. Topologically associated domain (TAD) boundaries enriched with histone modifications are associated with different distributions of genes and the expression levels. Toxin-coding genes in the same loop are highly expressed, implying that the importance of epigenetic regulation during envenomination. On a smaller scale, the epigenetic markers affect transcriptional regulation by controlling the recruitment/inhibition of transcription initiation complexes. CONCLUSIONS Chromatin structure and epigenetic modifications could play a vital status role in the mechanisms of venom regulation in B. multicinctus.
Collapse
Affiliation(s)
- Xuejiao Liao
- Pharmacy College, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Shuai Guo
- Pharmacy College, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Xianmei Yin
- Pharmacy College, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Baosheng Liao
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Mingqian Li
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - He Su
- Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, 510006, China
| | - Qiushi Li
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Jin Pei
- Pharmacy College, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Jihai Gao
- Pharmacy College, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Juan Lei
- College of Life Sciences, Beijing Normal University, Beijing, 100875, China
| | - Xiwen Li
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Zhihai Huang
- Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, 510006, China
| | - Jiang Xu
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China.
| | - Shilin Chen
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China.
| |
Collapse
|
191
|
Knytl M, Fornaini NR. Measurement of Chromosomal Arms and FISH Reveal Complex Genome Architecture and Standardized Karyotype of Model Fish, Genus Carassius. Cells 2021; 10:2343. [PMID: 34571992 PMCID: PMC8471844 DOI: 10.3390/cells10092343] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Revised: 08/20/2021] [Accepted: 08/29/2021] [Indexed: 11/23/2022] Open
Abstract
The widely distributed ray-finned fish genus Carassius is very well known due to its unique biological characteristics such as polyploidy, clonality, and/or interspecies hybridization. These biological characteristics have enabled Carassius species to be successfully widespread over relatively short period of evolutionary time. Therefore, this fish model deserves to be the center of attention in the research field. Some studies have already described the Carassius karyotype, but results are inconsistent in the number of morphological categories for individual chromosomes. We investigated three focal species: Carassius auratus, C. carassius and C. gibelio with the aim to describe their standardized diploid karyotypes, and to study their evolutionary relationships using cytogenetic tools. We measured length (q+plength) of each chromosome and calculated centromeric index (i value). We found: (i) The relationship between q+plength and i value showed higher similarity of C. auratus and C. carassius. (ii) The variability of i value within each chromosome expressed by means of the first quartile (Q1) up to the third quartile (Q3) showed higher similarity of C. carassius and C. gibelio. (iii) The fluorescent in situ hybridization (FISH) analysis revealed higher similarity of C. auratus and C. gibelio. (iv) Standardized karyotype formula described using median value (Q2) showed differentiation among all investigated species: C. auratus had 24 metacentric (m), 40 submetacentric (sm), 2 subtelocentric (st), 2 acrocentric (a) and 32 telocentric (T) chromosomes (24m+40sm+2st+2a+32T); C. carassius: 16m+34sm+8st+42T; and C. gibelio: 16m+22sm+10st+2a+50T. (v) We developed R scripts applicable for the description of standardized karyotype for any other species. The diverse results indicated unprecedented complex genomic and chromosomal architecture in the genus Carassius probably influenced by its unique biological characteristics which make the study of evolutionary relationships more difficult than it has been originally postulated.
Collapse
Affiliation(s)
- Martin Knytl
- Department of Cell Biology, Faculty of Science, Charles University, 12843 Prague, Czech Republic;
| | | |
Collapse
|
192
|
Cornforth MN, Bedford JS, Bailey SM. Destabilizing Effects of Ionizing Radiation on Chromosomes: Sizing up the Damage. Cytogenet Genome Res 2021; 161:328-351. [PMID: 34488218 DOI: 10.1159/000516523] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 02/16/2021] [Indexed: 11/19/2022] Open
Abstract
For long-term survival and evolution, all organisms have depended on a delicate balance between processes involved in maintaining stability of their genomes and opposing processes that lead toward destabilization. At the level of mammalian somatic cells in renewal tissues, events or conditions that can tip this balance toward instability have attracted special interest in connection with carcinogenesis. Mutations affecting DNA (and its subsequent repair) would, of course, be a major consideration here. These may occur spontaneously through endogenous cellular processes or as a result of exposure to mutagenic environmental agents. It is in this context that we discuss the rather unique destabilizing effects of ionizing radiation (IR) in terms of its ability to cause large-scale structural rearrangements to the genome. We present arguments supporting the conclusion that these and other important effects of IR originate largely from microscopically visible chromosome aberrations.
Collapse
Affiliation(s)
- Michael N Cornforth
- Department of Radiation Oncology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Joel S Bedford
- Department of Environmental & Radiological Health Sciences, Colorado State University, Fort Collins, Colorado, USA
| | - Susan M Bailey
- Department of Environmental & Radiological Health Sciences, Colorado State University, Fort Collins, Colorado, USA
| |
Collapse
|
193
|
Danieli A, Papantonis A. Spatial genome architecture and the emergence of malignancy. Hum Mol Genet 2021; 29:R197-R204. [PMID: 32619215 DOI: 10.1093/hmg/ddaa128] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 06/16/2020] [Accepted: 06/16/2020] [Indexed: 01/30/2023] Open
Abstract
Human chromosomes are large spatially and hierarchically structured entities, the integrity of which needs to be preserved throughout the lifespan of the cell and in conjunction with cell cycle progression. Preservation of chromosomal structure is important for proper deployment of cell type-specific gene expression programs. Thus, aberrations in the integrity and structure of chromosomes will predictably lead to disease, including cancer. Here, we provide an updated standpoint with respect to chromatin misfolding and the emergence of various cancer types. We discuss recent studies implicating the disruption of topologically associating domains, switching between active and inactive compartments, rewiring of promoter-enhancer interactions in malignancy as well as the effects of single nucleotide polymorphisms in non-coding regions involved in long-range regulatory interactions. In light of these findings, we argue that chromosome conformation studies may now also be useful for patient diagnosis and drug target discovery.
Collapse
Affiliation(s)
- Adi Danieli
- Institute of Pathology, University Medical Center Göttingen, 37075 Göttingen, Germany
| | - Argyris Papantonis
- Institute of Pathology, University Medical Center Göttingen, 37075 Göttingen, Germany
| |
Collapse
|
194
|
Forte G, Michieletto D, Marenduzzo D, Orlandini E. Investigating site-selection mechanisms of retroviral integration in supercoiled DNA braids. J R Soc Interface 2021; 18:20210229. [PMID: 34428944 PMCID: PMC8385341 DOI: 10.1098/rsif.2021.0229] [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] [Indexed: 01/08/2023] Open
Abstract
We theoretically study the integration of short viral DNA in a DNA braid made up by two entwined double-stranded DNA molecules. We show that the statistics of single integration events substantially differ in the straight and buckled, or plectonemic, phase of the braid and are more likely in the latter. We further discover that integration is most likely close to plectoneme tips, where the larger bending energy helps overcome the associated energy barrier and that successive integration events are spatio-temporally correlated, suggesting a potential mechanistic explanation of clustered integration sites in host genomes. The braid geometry we consider provides a novel experimental set-up to quantify integration in a supercoiled substrate in vitro, and to better understand the role of double-stranded DNA topology during this process.
Collapse
Affiliation(s)
- G Forte
- SUPA, School of Physics and Astronomy, Peter Guthrie Tait Road, University of Edinburgh, Edinburgh EH9 3FD, UK.,MRC Human Genetics Unit, MRC Institute of Genetics and Cancer, University of Edinburgh, Western General Hospital, Edinburgh EH4 2XU, UK
| | - D Michieletto
- SUPA, School of Physics and Astronomy, Peter Guthrie Tait Road, University of Edinburgh, Edinburgh EH9 3FD, UK.,MRC Human Genetics Unit, MRC Institute of Genetics and Cancer, University of Edinburgh, Western General Hospital, Edinburgh EH4 2XU, UK
| | - D Marenduzzo
- SUPA, School of Physics and Astronomy, Peter Guthrie Tait Road, University of Edinburgh, Edinburgh EH9 3FD, UK
| | - E Orlandini
- Dipartimento di Fisica e Astronomia and Sezione INFN, Universitá degli Studi di Padova, 35131 Padova, Italy
| |
Collapse
|
195
|
Mulia GE, Picanço-Castro V, Stavrou EF, Athanassiadou A, Figueiredo ML. Advances in the Development and the Applications of Non-viral, Episomal Vectors for Gene Therapy. Hum Gene Ther 2021; 32:1076-1095. [PMID: 34348480 PMCID: PMC8819515 DOI: 10.1089/hum.2020.310] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Nonviral and nonintegrating episomal vectors are reemerging as a valid, alternative technology to integrating viral vectors for gene therapy, due to their more favorable safety profile, significantly lower risk for insertional mutagenesis, and a lesser potential for innate immune reactions, in addition to their low production cost. Over the past few years, attempts have been made to generate highly functional nonviral vectors that display long-term maintenance within cells and promote more sustained gene expression relative to conventional plasmids. Extensive research into the parameters that stabilize the episomal DNA within dividing and nondividing cells has shed light into the genetic and epigenetic mechanisms that govern replication and transcription of episomal DNA within a mammalian nucleus in long-term cell culture. Episomal vectors based on scaffold/matrix attachment regions (S/MARs) do not integrate into the genomic DNA and address the serious problem of plasmid loss during mitosis by providing mitotic stability to established plasmids, which results in long-term transfection and transgene expression. The inclusion, in such vectors, of an origin of replication—initiation region—from the human genome has greatly enhanced their performance in primary cell culture. A number of vectors that function as episomes have arisen, which are either devoid or depleted of harmful CpG sequences and bacterial genes, and their effectiveness, as well as that of nonintegrating viral episomes, is enhanced when combined with S/MAR elements. As a result of these advances, an “S/MAR technology” has emerged for the production of efficient episomal vectors. Significant research continues in this field and innovations, in combination with promising systems based on nanoparticles and potentially combined with physical delivery methods, will enable the generation of optimized systems with scale-up and clinical application suitability utilizing episomal vectors.
Collapse
Affiliation(s)
- Grace E Mulia
- Purdue University, Basic Medical Sciences, West Lafayette, Indiana, United States;
| | - Virginia Picanço-Castro
- University of Sao Paulo Faculty of Medicine of Ribeirao Preto, 54539, Center for Cell-based Therapy, Ribeirao Preto, São Paulo, Brazil;
| | - Eleana F Stavrou
- University of Patras, Department of General Biology, Patras, Greece;
| | - Aglaia- Athanassiadou
- University of Patras Medical School, General Biology, Asklepiou str, University Campus, Rion Patras, Greece, 26504;
| | - Marxa L Figueiredo
- Purdue University, Basic Medical Sciences, 625 Harrison St., LYNN 2177, West Lafayette, Indiana, United States, 47907;
| |
Collapse
|
196
|
Papale A, Smrek J, Rosa A. Nanorheology of active-passive polymer mixtures differentiates between linear and ring polymer topology. SOFT MATTER 2021; 17:7111-7117. [PMID: 34254620 DOI: 10.1039/d1sm00665g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
We study the motion of dispersed nanoprobes in entangled active-passive polymer mixtures. By comparing the two architectures of linear vs. unconcatenated and unknotted circular polymers, we demonstrate that novel, rich physics emerge. For both polymer architectures, nanoprobes of size smaller than the entanglement threshold of the solution move faster as activity is increased and more energy is pumped in the system. For larger nanoprobes, a surprising phenomenon occurs: while in linear solutions they move qualitatively as before, in active-passive ring solutions nanoprobes decelerate with respect to the purely passive conditions. We rationalize this effect in terms of the non-equilibrium, topology-dependent association (clustering) of nanoprobes to the cold component of the ring mixture reminiscent of the recently discovered [Weber et al., Phys. Rev. Lett., 2016, 116, 058301] phase separation in scalar active-passive mixtures. We conclude with a potential connection to the microrheology of the chromatin in the nuclei of the cells.
Collapse
Affiliation(s)
- Andrea Papale
- SISSA - Scuola Internazionale Superiore di Studi Avanzati, Via Bonomea 265, 34136 Trieste, Italy.
| | - Jan Smrek
- Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090 Vienna, Austria.
| | - Angelo Rosa
- SISSA - Scuola Internazionale Superiore di Studi Avanzati, Via Bonomea 265, 34136 Trieste, Italy.
| |
Collapse
|
197
|
Boltsis I, Grosveld F, Giraud G, Kolovos P. Chromatin Conformation in Development and Disease. Front Cell Dev Biol 2021; 9:723859. [PMID: 34422840 PMCID: PMC8371409 DOI: 10.3389/fcell.2021.723859] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 07/16/2021] [Indexed: 01/23/2023] Open
Abstract
Chromatin domains and loops are important elements of chromatin structure and dynamics, but much remains to be learned about their exact biological role and nature. Topological associated domains and functional loops are key to gene expression and hold the answer to many questions regarding developmental decisions and diseases. Here, we discuss new findings, which have linked chromatin conformation with development, differentiation and diseases and hypothesized on various models while integrating all recent findings on how chromatin architecture affects gene expression during development, evolution and disease.
Collapse
Affiliation(s)
- Ilias Boltsis
- Department of Cell Biology, Erasmus Medical Centre, Rotterdam, Netherlands
| | - Frank Grosveld
- Department of Cell Biology, Erasmus Medical Centre, Rotterdam, Netherlands
| | - Guillaume Giraud
- Department of Cell Biology, Erasmus Medical Centre, Rotterdam, Netherlands
- Cancer Research Center of Lyon – INSERM U1052, Lyon, France
| | - Petros Kolovos
- Department of Molecular Biology and Genetics, Democritus University of Thrace, Alexandroupolis, Greece
| |
Collapse
|
198
|
Nussinov R, Zhang M, Maloney R, Jang H. Ras isoform-specific expression, chromatin accessibility, and signaling. Biophys Rev 2021; 13:489-505. [PMID: 34466166 PMCID: PMC8355297 DOI: 10.1007/s12551-021-00817-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Accepted: 06/29/2021] [Indexed: 12/12/2022] Open
Abstract
The anchorage of Ras isoforms in the membrane and their nanocluster formations have been studied extensively, including their detailed interactions, sizes, preferred membrane environments, chemistry, and geometry. However, the staggering challenge of their epigenetics and chromatin accessibility in distinct cell states and types, which we propose is a major factor determining their specific expression, still awaits unraveling. Ras isoforms are distinguished by their C-terminal hypervariable region (HVR) which acts in intracellular transport, regulation, and membrane anchorage. Here, we review some isoform-specific activities at the plasma membrane from a structural dynamic standpoint. Inspired by physics and chemistry, we recognize that understanding functional specificity requires insight into how biomolecules can organize themselves in different cellular environments. Within this framework, we suggest that isoform-specific expression may largely be controlled by the chromatin density and physical compaction, which allow (or curb) access to "chromatinized DNA." Genes are preferentially expressed in tissues: proteins expressed in pancreatic cells may not be equally expressed in lung cells. It is the rule-not an exception, and it can be at least partly understood in terms of chromatin organization and accessibility state. Genes are expressed when they can be sufficiently exposed to the transcription machinery, and they are less so when they are persistently buried in dense chromatin. Notably, chromatin accessibility can similarly determine expression of drug resistance genes.
Collapse
Affiliation(s)
- Ruth Nussinov
- Computational Structural Biology Section Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research in the Laboratory of Cancer Immunometabolism National Cancer Institute, 1050 Boyles St, Frederick, MD 21702 USA
- Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine Tel Aviv University, 69978 Tel Aviv, Israel
| | - Mingzhen Zhang
- Computational Structural Biology Section Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research in the Laboratory of Cancer Immunometabolism National Cancer Institute, 1050 Boyles St, Frederick, MD 21702 USA
| | - Ryan Maloney
- Computational Structural Biology Section Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research in the Laboratory of Cancer Immunometabolism National Cancer Institute, 1050 Boyles St, Frederick, MD 21702 USA
| | - Hyunbum Jang
- Computational Structural Biology Section Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research in the Laboratory of Cancer Immunometabolism National Cancer Institute, 1050 Boyles St, Frederick, MD 21702 USA
| |
Collapse
|
199
|
Escudeiro A, Adega F, Robinson TJ, Heslop-Harrison JS, Chaves R. Analysis of the Robertsonian (1;29) fusion in Bovinae reveals a common mechanism: insights into its clinical occurrence and chromosomal evolution. Chromosome Res 2021; 29:301-312. [PMID: 34331632 DOI: 10.1007/s10577-021-09667-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 07/11/2021] [Accepted: 07/14/2021] [Indexed: 10/20/2022]
Abstract
The interest in Robertsonian fusion chromosomes (Rb fusions), sometimes referred to as Robertsonian translocations, derives from their impact on mammalian karyotype evolution, as well from their influence on fertility and disease. The formation of a Rb chromosome necessitates the occurrence of double strand breaks in the pericentromeric regions of two chromosomes in the satellite DNA (satDNA) sequences. Here, we report on the fine-scale molecular analysis of the centromeric satDNA families in the Rb(1;29) translocation of domestic cattle and six antelope species of the subfamily Bovinae. We do so from two perspectives: its occurrence as a chromosomal abnormality in cattle and, secondly, as a fixed evolutionarily rearrangement in spiral-horned antelope (Tragelaphini). By analysing the reorganization of satDNAs in the centromeric regions of translocated chromosomes, we show that Rb fusions are multistep, complex rearrangements which entail the precise elimination and reorganization of specific (peri)centromeric satDNA sequences. Importantly, these structural changes do not influence the centromeric activity of the satellite DNAs that provide segregation stability to the translocated chromosome. Our results suggest a common mechanism for Rb fusions in these bovids and, more widely, for mammals in general.
Collapse
Affiliation(s)
- A Escudeiro
- Department of Genetics and Biotechnology (DGB), CAG - Laboratory of Cytogenomics and Animal Genomics, University of Trás-os-Montes e Alto Douro, Vila Real, Portugal.,BioISI - Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisbon, Lisbon, Portugal
| | - F Adega
- Department of Genetics and Biotechnology (DGB), CAG - Laboratory of Cytogenomics and Animal Genomics, University of Trás-os-Montes e Alto Douro, Vila Real, Portugal.,BioISI - Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisbon, Lisbon, Portugal
| | - T J Robinson
- Department of Botany and Zoology, Stellenbosch University, Stellenbosch, South Africa
| | - J S Heslop-Harrison
- Department of Genetics and Genome Biology, University of Leicester, Leicester, UK
| | - R Chaves
- Department of Genetics and Biotechnology (DGB), CAG - Laboratory of Cytogenomics and Animal Genomics, University of Trás-os-Montes e Alto Douro, Vila Real, Portugal. .,BioISI - Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisbon, Lisbon, Portugal.
| |
Collapse
|
200
|
Li X, Zeng G, Li A, Zhang Z. DeTOKI identifies and characterizes the dynamics of chromatin TAD-like domains in a single cell. Genome Biol 2021; 22:217. [PMID: 34311744 PMCID: PMC8314462 DOI: 10.1186/s13059-021-02435-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 07/14/2021] [Indexed: 12/19/2022] Open
Abstract
Topologically associating domains (TAD) are a key structure of the 3D mammalian genomes. However, the prevalence and dynamics of TAD-like domains in single cells remain elusive. Here we develop a new algorithm, named deTOKI, to decode TAD-like domains with single-cell Hi-C data. By non-negative matrix factorization, deTOKI seeks regions that insulate the genome into blocks with minimal chance of clustering. deTOKI outperforms competing tools and reliably identifies TAD-like domains in single cells. Finally, we find that TAD-like domains are not only prevalent, but also subject to tight regulation in single cells.
Collapse
Affiliation(s)
- Xiao Li
- CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, and China National Center for Bioinformation, Beijing, 100101, China
- School of Life Science, University of Chinese Academy of Sciences, Beijing, People's Republic of China
- School of Artificial Intelligence, University of Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Guangjie Zeng
- State Key Laboratory of Software Development Environment, School of Computer Science, Beihang University, 100083, Beijing, People's Republic of China
| | - Angsheng Li
- State Key Laboratory of Software Development Environment, School of Computer Science, Beihang University, 100083, Beijing, People's Republic of China
| | - Zhihua Zhang
- CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, and China National Center for Bioinformation, Beijing, 100101, China.
- School of Life Science, University of Chinese Academy of Sciences, Beijing, People's Republic of China.
- School of Artificial Intelligence, University of Chinese Academy of Sciences, Beijing, People's Republic of China.
| |
Collapse
|