1
|
Fajri N, Petryk N. Monitoring and quantifying replication fork dynamics with high-throughput methods. Commun Biol 2024; 7:729. [PMID: 38877080 PMCID: PMC11178896 DOI: 10.1038/s42003-024-06412-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Accepted: 06/04/2024] [Indexed: 06/16/2024] Open
Abstract
Before each cell division, eukaryotic cells must replicate their chromosomes to ensure the accurate transmission of genetic information. Chromosome replication involves more than just DNA duplication; it also includes chromatin assembly, inheritance of epigenetic marks, and faithful resumption of all genomic functions after replication. Recent progress in quantitative technologies has revolutionized our understanding of the complexity and dynamics of DNA replication forks at both molecular and genomic scales. Here, we highlight the pivotal role of these novel methods in uncovering the principles and mechanisms of chromosome replication. These technologies have illuminated the regulation of genome replication programs, quantified the impact of DNA replication on genomic mutations and evolutionary processes, and elucidated the mechanisms of replication-coupled chromatin assembly and epigenome maintenance.
Collapse
Affiliation(s)
- Nora Fajri
- UMR9019 - CNRS, Intégrité du Génome et Cancers, Université Paris-Saclay, Gustave Roussy, Villejuif, France, 114 rue Edouard Vaillant, 94805, Villejuif, France
| | - Nataliya Petryk
- UMR9019 - CNRS, Intégrité du Génome et Cancers, Université Paris-Saclay, Gustave Roussy, Villejuif, France, 114 rue Edouard Vaillant, 94805, Villejuif, France.
| |
Collapse
|
2
|
Bugallo A, Sánchez M, Fernández-García M, Segurado M. S-phase checkpoint prevents leading strand degradation from strand-associated nicks at stalled replication forks. Nucleic Acids Res 2024; 52:5121-5137. [PMID: 38520409 PMCID: PMC11109941 DOI: 10.1093/nar/gkae192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Revised: 03/01/2024] [Accepted: 03/07/2024] [Indexed: 03/25/2024] Open
Abstract
The S-phase checkpoint is involved in coupling DNA unwinding with nascent strand synthesis and is critical to maintain replication fork stability in conditions of replicative stress. However, its role in the specific regulation of leading and lagging strands at stalled forks is unclear. By conditionally depleting RNaseH2 and analyzing polymerase usage genome-wide, we examine the enzymology of DNA replication during a single S-phase in the presence of replicative stress and show that there is a differential regulation of lagging and leading strands. In checkpoint proficient cells, lagging strand replication is down-regulated through an Elg1-dependent mechanism. Nevertheless, when checkpoint function is impaired we observe a defect specifically at the leading strand, which was partially dependent on Exo1 activity. Further, our genome-wide mapping of DNA single-strand breaks reveals that strand discontinuities highly accumulate at the leading strand in HU-treated cells, whose dynamics are affected by checkpoint function and Exo1 activity. Our data reveal an unexpected role of Exo1 at the leading strand and support a model of fork stabilization through prevention of unrestrained Exo1-dependent resection of leading strand-associated nicks after fork stalling.
Collapse
Affiliation(s)
- Alberto Bugallo
- Instituto de Biología Funcional y Genómica (CSIC/USAL), Campus Miguel de Unamuno, Salamanca 37007, Spain
| | - Mar Sánchez
- Instituto de Biología Funcional y Genómica (CSIC/USAL), Campus Miguel de Unamuno, Salamanca 37007, Spain
| | - María Fernández-García
- Instituto de Biología Funcional y Genómica (CSIC/USAL), Campus Miguel de Unamuno, Salamanca 37007, Spain
| | - Mónica Segurado
- Instituto de Biología Funcional y Genómica (CSIC/USAL), Campus Miguel de Unamuno, Salamanca 37007, Spain
- Departamento de Microbiología y Genética (USAL), Campus Miguel de Unamuno, Salamanca 37007, Spain
| |
Collapse
|
3
|
Elango R, Nilavar N, Li AG, Duffey EE, Jiang Y, Nguyen D, Abakir A, Willis NA, Houseley J, Scully R. Two-ended recombination at a Flp-nickase-broken replication fork. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.10.588130. [PMID: 38645103 PMCID: PMC11030319 DOI: 10.1101/2024.04.10.588130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/23/2024]
Abstract
Collision of a replication fork with a DNA nick is thought to generate a one-ended break, fostering genomic instability. Collision of the opposing converging fork with the nick could, in principle, form a second DNA end, enabling conservative repair by homologous recombination (HR). To study mechanisms of nickase-induced HR, we developed the Flp recombinase "step arrest" nickase in mammalian cells. Flp-nickase-induced HR entails two-ended, BRCA2/RAD51-dependent short tract gene conversion (STGC), BRCA2/RAD51-independent long tract gene conversion, and discoordinated two-ended invasions. HR induced by a replication-independent break and by the Flp-nickase differ in their dependence on BRCA1 . To determine the origin of the second DNA end during Flp-nickase-induced STGC, we blocked the opposing fork using a site-specific Tus/ Ter replication fork barrier. Flp-nickase-induced STGC remained robust and two-ended. Thus, collision of a single replication fork with a Flp-nick can trigger two-ended HR, possibly reflecting replicative bypass of lagging strand nicks. This response may limit genomic instability during replication of a nicked DNA template.
Collapse
|
4
|
Piguet B, Houseley J. Transcription as source of genetic heterogeneity in budding yeast. Yeast 2024; 41:171-185. [PMID: 38196235 DOI: 10.1002/yea.3926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Revised: 12/10/2023] [Accepted: 12/20/2023] [Indexed: 01/11/2024] Open
Abstract
Transcription presents challenges to genome stability both directly, by altering genome topology and exposing single-stranded DNA to chemical insults and nucleases, and indirectly by introducing obstacles to the DNA replication machinery. Such obstacles include the RNA polymerase holoenzyme itself, DNA-bound regulatory factors, G-quadruplexes and RNA-DNA hybrid structures known as R-loops. Here, we review the detrimental impacts of transcription on genome stability in budding yeast, as well as the mitigating effects of transcription-coupled nucleotide excision repair and of systems that maintain DNA replication fork processivity and integrity. Interactions between DNA replication and transcription have particular potential to induce mutation and structural variation, but we conclude that such interactions must have only minor effects on DNA replication by the replisome with little if any direct mutagenic outcome. However, transcription can significantly impair the fidelity of replication fork rescue mechanisms, particularly Break Induced Replication, which is used to restart collapsed replication forks when other means fail. This leads to de novo mutations, structural variation and extrachromosomal circular DNA formation that contribute to genetic heterogeneity, but only under particular conditions and in particular genetic contexts, ensuring that the bulk of the genome remains extremely stable despite the seemingly frequent interactions between transcription and DNA replication.
Collapse
|
5
|
Martins F, Rosspopoff O, Carlevaro-Fita J, Forey R, Offner S, Planet E, Pulver C, Pak H, Huber F, Michaux J, Bassani-Sternberg M, Turelli P, Trono D. A Cluster of Evolutionarily Recent KRAB Zinc Finger Proteins Protects Cancer Cells from Replicative Stress-Induced Inflammation. Cancer Res 2024; 84:808-826. [PMID: 38345497 PMCID: PMC10940857 DOI: 10.1158/0008-5472.can-23-1237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 10/15/2023] [Accepted: 01/19/2024] [Indexed: 03/16/2024]
Abstract
Heterochromatin loss and genetic instability enhance cancer progression by favoring clonal diversity, yet uncontrolled replicative stress leads to mitotic catastrophe and inflammatory responses that promote immune rejection. KRAB domain-containing zinc finger proteins (KZFP) contribute to heterochromatin maintenance at transposable elements (TE). Here, we identified an association of upregulation of a cluster of primate-specific KZFPs with poor prognosis, increased copy-number alterations, and changes in the tumor microenvironment in diffuse large B-cell lymphoma (DLBCL). Depleting two of these KZFPs targeting evolutionarily recent TEs, ZNF587 and ZNF417, impaired the proliferation of cells derived from DLBCL and several other tumor types. ZNF587 and ZNF417 depletion led to heterochromatin redistribution, replicative stress, and cGAS-STING-mediated induction of an interferon/inflammatory response, which enhanced susceptibility to macrophage-mediated phagocytosis and increased surface expression of HLA-I, together with presentation of a neoimmunopeptidome. Thus, cancer cells can exploit KZFPs to dampen TE-originating surveillance mechanisms, which likely facilitates clonal expansion, diversification, and immune evasion. SIGNIFICANCE Upregulation of a cluster of primate-specific KRAB zinc finger proteins in cancer cells prevents replicative stress and inflammation by regulating heterochromatin maintenance, which could facilitate the development of improved biomarkers and treatments.
Collapse
Affiliation(s)
- Filipe Martins
- School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
- Clinics of Medical Oncology, Cantonal Hospital of Fribourg (HFR), Fribourg, Switzerland
| | - Olga Rosspopoff
- School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Joana Carlevaro-Fita
- School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Romain Forey
- School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Sandra Offner
- School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Evarist Planet
- School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Cyril Pulver
- School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - HuiSong Pak
- Department of Oncology, Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne, Switzerland
- Agora Cancer Research Centre, Lausanne, Switzerland
- Ludwig Institute for Cancer Research, University of Lausanne, Lausanne, Switzerland
| | - Florian Huber
- Department of Oncology, Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne, Switzerland
- Agora Cancer Research Centre, Lausanne, Switzerland
- Ludwig Institute for Cancer Research, University of Lausanne, Lausanne, Switzerland
| | - Justine Michaux
- Department of Oncology, Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne, Switzerland
- Agora Cancer Research Centre, Lausanne, Switzerland
- Ludwig Institute for Cancer Research, University of Lausanne, Lausanne, Switzerland
| | - Michal Bassani-Sternberg
- Department of Oncology, Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne, Switzerland
- Agora Cancer Research Centre, Lausanne, Switzerland
- Ludwig Institute for Cancer Research, University of Lausanne, Lausanne, Switzerland
| | - Priscilla Turelli
- School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Didier Trono
- School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| |
Collapse
|
6
|
Xu S, Wei J, Sun S, Zhang J, Chan TF, Li Y. SSBlazer: a genome-wide nucleotide-resolution model for predicting single-strand break sites. Genome Biol 2024; 25:46. [PMID: 38347618 PMCID: PMC10863285 DOI: 10.1186/s13059-024-03179-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 01/24/2024] [Indexed: 02/15/2024] Open
Abstract
Single-strand breaks are the major DNA damage in the genome and serve a crucial role in various biological processes. To reveal the significance of single-strand breaks, multiple sequencing-based single-strand break detection methods have been developed, which are costly and unfeasible for large-scale analysis. Hence, we propose SSBlazer, an explainable and scalable deep learning framework for single-strand break site prediction at the nucleotide level. SSBlazer is a lightweight model with robust generalization capabilities across various species and is capable of numerous unexplored SSB-related applications.
Collapse
Affiliation(s)
- Sheng Xu
- Department of Computer Science and Engineering, The Chinese University of Hong Kong, 100871, Hong Kong SAR, China
- Research Institute of Intelligent Complex Systems, Fudan University, 220 Handan Rd, Shanghai, 200437, China
- Shanghai AI Lab, 422 Jingan Rd, 200041, Shanghai, China
| | - Junkang Wei
- Department of Computer Science and Engineering, The Chinese University of Hong Kong, 100871, Hong Kong SAR, China.
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, USA.
| | - Siqi Sun
- Research Institute of Intelligent Complex Systems, Fudan University, 220 Handan Rd, Shanghai, 200437, China
- Shanghai AI Lab, 422 Jingan Rd, 200041, Shanghai, China
| | - Jizhou Zhang
- School of Life Sciences, The Chinese University of Hong Kong, 100871, Hong Kong SAR, China
- State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, 100871, Hong Kong SAR, China
| | - Ting-Fung Chan
- School of Life Sciences, The Chinese University of Hong Kong, 100871, Hong Kong SAR, China
- State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, 100871, Hong Kong SAR, China
| | - Yu Li
- Department of Computer Science and Engineering, The Chinese University of Hong Kong, 100871, Hong Kong SAR, China.
- The CUHK Shenzhen Research Institute, Hi-Tech Park, Nanshan, 518057, Shenzhen, China.
| |
Collapse
|
7
|
Liang Y, Yuan Q, Zheng Q, Mei Z, Song Y, Yan H, Yang J, Wu S, Yuan J, Wu W. DNA Damage Atlas: an atlas of DNA damage and repair. Nucleic Acids Res 2024; 52:D1218-D1226. [PMID: 37831087 PMCID: PMC10767978 DOI: 10.1093/nar/gkad845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2023] [Revised: 09/06/2023] [Accepted: 09/21/2023] [Indexed: 10/14/2023] Open
Abstract
DNA damage and its improper repair are the major source of genomic alterations responsible for many human diseases, particularly cancer. To aid researchers in understanding the underlying mechanisms of genome instability, a number of genome-wide profiling approaches have been developed to monitor DNA damage and repair events. The rapid accumulation of published datasets underscores the critical necessity of a comprehensive database to curate sequencing data on DNA damage and repair intermediates. Here, we present DNA Damage Atlas (DDA, http://www.bioinformaticspa.com/DDA/), the first large-scale repository of DNA damage and repair information. Currently, DDA comprises 6,030 samples from 262 datasets by 59 technologies, covering 16 species, 10 types of damage and 135 treatments. Data collected in DDA was processed through a standardized workflow, including quality checks, hotspots identification and a series of feature characterization for the hotspots. Notably, DDA encompasses analyses of highly repetitive regions, ribosomal DNA and telomere. DDA offers a user-friendly interface that facilitates browsing, searching, genome browser visualization, hotspots comparison and data downloading, enabling convenient and thorough exploration for datasets of interest. In summary, DDA will stand as a valuable resource for research in genome instability and its association with diseases.
Collapse
Affiliation(s)
- Yu Liang
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China
| | - Qingqing Yuan
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China
| | - Qijie Zheng
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China
| | - Zilv Mei
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China
| | - Yawei Song
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China
| | - Huan Yan
- GMU-GIBH Joint School of Life Sciences, The Guangdong-Hong Kong-Macau Joint Laboratory for Cell Fate Regulation and Diseases, Guangzhou National Laboratory, Guangzhou Medical University, Guangzhou, China
| | - Jiajie Yang
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China
| | - Shuheng Wu
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China
| | - Jiao Yuan
- GMU-GIBH Joint School of Life Sciences, The Guangdong-Hong Kong-Macau Joint Laboratory for Cell Fate Regulation and Diseases, Guangzhou National Laboratory, Guangzhou Medical University, Guangzhou, China
| | - Wei Wu
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China
| |
Collapse
|
8
|
Hadjicharalambous A, Whale AJ, Can G, Skehel JM, Houseley JM, Zegerman P. Checkpoint kinase interaction with DNA polymerase alpha regulates replication progression during stress. Wellcome Open Res 2023; 8:327. [PMID: 37766847 PMCID: PMC10521137 DOI: 10.12688/wellcomeopenres.19617.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/06/2023] [Indexed: 09/29/2023] Open
Abstract
Background: In eukaryotes, replication stress activates a checkpoint response, which facilitates genome duplication by stabilising the replisome. How the checkpoint kinases regulate the replisome remains poorly understood. The aim of this study is to identify new targets of checkpoint kinases within the replisome during replication stress. Methods: Here we use an unbiased biotin proximity-ligation approach in Saccharomyces cerevisiae to identify new interactors and substrates of the checkpoint kinase Rad53 in vivo. Results: From this screen, we identified the replication initiation factor Sld7 as a Rad53 substrate, and Pol1, the catalytic subunit of polymerase a, as a Rad53-interactor. We showed that CDK phosphorylation of Pol1 mediates its interaction with Rad53. Combined with other interactions between Rad53 and the replisome, this Rad53-Pol1 interaction is important for viability and replisome progression during replication stress. Conclusions: Together, we explain how the interactions of Rad53 with the replisome are controlled by both replication stress and the cell cycle, and why these interactions might be important for coordinating the stabilisation of both the leading and lagging strand machineries.
Collapse
Affiliation(s)
| | - Alex J. Whale
- Epigenetics Programme, Babraham Institute, University of Cambridge, Cambridge, England, CB22 3AT, UK
| | - Geylani Can
- Department of Biochemistry, University of Cambridge, Cambridge, England, CB2 1GA, UK
| | - J. Mark Skehel
- Medical Research Council Laboratory of Molecular Biology, Cambridge Biomedical Campus, London, England, CB2 0QH, UK
| | - Jonathan M. Houseley
- Epigenetics Programme, Babraham Institute, University of Cambridge, Cambridge, England, CB22 3AT, UK
| | - Philip Zegerman
- Department of Biochemistry, University of Cambridge, Cambridge, England, CB2 1GA, UK
| |
Collapse
|
9
|
Xu W, Liu C, Zhang Z, Sun C, Li Q, Li K, Jiang H, Li W, Sun Q. DEtail-seq is an ultra-efficient and convenient method for meiotic DNA break profiling in multiple organisms. SCIENCE CHINA. LIFE SCIENCES 2023; 66:1392-1407. [PMID: 36723795 DOI: 10.1007/s11427-022-2277-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 01/02/2023] [Indexed: 06/15/2023]
Abstract
Programmed DNA double-strand break (DSB) formation is a crucial step in meiotic recombination, yet techniques for high-efficiency and precise mapping of the 3' ends of DSBs are still in their infancy. Here, we report a novel technique, named DNA End tailing and sequencing (DEtail-seq), which can directly and ultra-efficiently characterize the 3' ends of meiotic DSBs with near single-nucleotide resolution in a variety of species, including yeast, mouse, and human. We find that the 3' ends of meiotic DSBs are stable without significant resection in budding yeast. Meiotic DSBs are strongly enriched in de novo H3K4me3 peaks in the mouse genome at leptotene stage. We also profile meiotic DSBs in human and find DSB hotspots are enriched near the common fragile sites during human meiosis, especially at CCCTC-binding factor (CTCF)-associated enhancers. Therefore, DEtail-seq provides a powerful method to detect DSB ends in various species, and our results provide new insights into the distribution and regulation of meiotic DSB hotspots.
Collapse
Affiliation(s)
- Wei Xu
- School of Life Sciences, Tsinghua University, Beijing, 100084, China.
- Tsinghua-Peking Center for Life Sciences, Beijing, 100084, China.
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518120, China.
| | - Chao Liu
- Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, 510623, China
| | - Zhe Zhang
- Department of Urology, Department of Andrology, Department of Reproductive Medicine Center, and Department of Human Sperm Bank, Peking University Third Hospital, Beijing, 100191, China
| | - Changbin Sun
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518120, China
| | - Qin Li
- School of Life Sciences, Tsinghua University, Beijing, 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing, 100084, China
| | - Kuan Li
- School of Life Sciences, Tsinghua University, Beijing, 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing, 100084, China
| | - Hui Jiang
- Department of Urology, Department of Andrology, Department of Reproductive Medicine Center, and Department of Human Sperm Bank, Peking University Third Hospital, Beijing, 100191, China.
| | - Wei Li
- Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, 510623, China.
| | - Qianwen Sun
- School of Life Sciences, Tsinghua University, Beijing, 100084, China.
- Tsinghua-Peking Center for Life Sciences, Beijing, 100084, China.
| |
Collapse
|
10
|
Liu Y, Wu X, d'Aubenton-Carafa Y, Thermes C, Chen CL. OKseqHMM: a genome-wide replication fork directionality analysis toolkit. Nucleic Acids Res 2023; 51:e22. [PMID: 36629249 PMCID: PMC9976876 DOI: 10.1093/nar/gkac1239] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 12/06/2022] [Accepted: 12/19/2022] [Indexed: 01/12/2023] Open
Abstract
During each cell division, tens of thousands of DNA replication origins are co-ordinately activated to ensure the complete duplication of the human genome. However, replication fork progression can be challenged by many factors, including co-directional and head-on transcription-replication conflicts (TRC). Head-on TRCs are more dangerous for genome integrity. To study the direction of replication fork movement and TRCs, we developed a bioinformatics toolkit called OKseqHMM (https://github.com/CL-CHEN-Lab/OK-Seq, https://doi.org/10.5281/zenodo.7428883). Then, we used OKseqHMM to analyse a large number of datasets obtained by Okazaki fragment sequencing to directly measure the genome-wide replication fork directionality (RFD) and to accurately predict replication initiation and termination at a fine resolution in organisms including yeast, mouse and human. We also successfully applied our analysis to other genome-wide sequencing techniques that also contain RFD information (e.g. eSPAN, TrAEL-seq). Our toolkit can be used to predict replication initiation and fork progression direction genome-wide in a wide range of cell models and growth conditions. Comparing the replication and transcription directions allows identifying loci at risk of TRCs, particularly head-on TRCs, and investigating their role in genome instability by checking DNA damage data, which is of prime importance for human health.
Collapse
Affiliation(s)
- Yaqun Liu
- Institut Curie, Université PSL, Sorbonne Université, CNRS UMR3244, Dynamics of Genetic Information, 75005 Paris, France
| | - Xia Wu
- Institut Curie, Université PSL, Sorbonne Université, CNRS UMR3244, Dynamics of Genetic Information, 75005 Paris, France
| | - Yves d'Aubenton-Carafa
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France
| | - Claude Thermes
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France
| | - Chun-Long Chen
- Institut Curie, Université PSL, Sorbonne Université, CNRS UMR3244, Dynamics of Genetic Information, 75005 Paris, France
| |
Collapse
|
11
|
Genome-wide measurement of DNA replication fork directionality and quantification of DNA replication initiation and termination with Okazaki fragment sequencing. Nat Protoc 2023; 18:1260-1295. [PMID: 36653528 DOI: 10.1038/s41596-022-00793-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 11/09/2022] [Indexed: 01/19/2023]
Abstract
Studying the dynamics of genome replication in mammalian cells has been historically challenging. To reveal the location of replication initiation and termination in the human genome, we developed Okazaki fragment sequencing (OK-seq), a quantitative approach based on the isolation and strand-specific sequencing of Okazaki fragments, the lagging strand replication intermediates. OK-seq quantitates the proportion of leftward- and rightward-oriented forks at every genomic locus and reveals the location and efficiency of replication initiation and termination events. Here we provide the detailed experimental procedures for performing OK-seq in unperturbed cultured human cells and budding yeast and the bioinformatics pipelines for data processing and computation of replication fork directionality. Furthermore, we present the analytical approach based on a hidden Markov model, which allows automated detection of ascending, descending and flat replication fork directionality segments revealing the zones of replication initiation, termination and unidirectional fork movement across the entire genome. These tools are essential for the accurate interpretation of human and yeast replication programs. The experiments and the data processing can be accomplished within six days. Besides revealing the genome replication program in fine detail, OK-seq has been instrumental in numerous studies unravelling mechanisms of genome stability, epigenome maintenance and genome evolution.
Collapse
|
12
|
Vergara X, Schep R, Medema RH, van Steensel B. From fluorescent foci to sequence: Illuminating DNA double strand break repair by high-throughput sequencing technologies. DNA Repair (Amst) 2022; 118:103388. [PMID: 36037787 DOI: 10.1016/j.dnarep.2022.103388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 08/16/2022] [Accepted: 08/17/2022] [Indexed: 11/25/2022]
Abstract
Technologies to study DNA double-strand break (DSB) repair have traditionally mostly relied on fluorescence read-outs, either by microscopy or flow cytometry. The advent of high throughput sequencing (HTS) has created fundamentally new opportunities to study the mechanisms underlying DSB repair. Here, we review the suite of HTS-based assays that are used to study three different aspects of DNA repair: detection of broken ends, protein recruitment and pathway usage. We highlight new opportunities that HTS technology offers towards a better understanding of the DSB repair process.
Collapse
Affiliation(s)
- Xabier Vergara
- Division of Gene Regulation, Netherlands Cancer Institute, 1066 CX Amsterdam, the Netherlands; Division of Cell Biology, Netherlands Cancer Institute, 1066 CX Amsterdam, the Netherlands; Oncode Institute, the Netherlands
| | - Ruben Schep
- Division of Gene Regulation, Netherlands Cancer Institute, 1066 CX Amsterdam, the Netherlands; Oncode Institute, the Netherlands
| | - René H Medema
- Division of Cell Biology, Netherlands Cancer Institute, 1066 CX Amsterdam, the Netherlands; Oncode Institute, the Netherlands.
| | - Bas van Steensel
- Division of Gene Regulation, Netherlands Cancer Institute, 1066 CX Amsterdam, the Netherlands; Oncode Institute, the Netherlands; Department of Cell Biology, Erasmus University Medical Centre, the Netherlands.
| |
Collapse
|
13
|
Nunes C, Depestel L, Mus L, Keller KM, Delhaye L, Louwagie A, Rishfi M, Whale A, Kara N, Andrews SR, Dela Cruz F, You D, Siddiquee A, Cologna CT, De Craemer S, Dolman E, Bartenhagen C, De Vloed F, Sanders E, Eggermont A, Bekaert SL, Van Loocke W, Bek JW, Dewyn G, Loontiens S, Van Isterdael G, Decaesteker B, Tilleman L, Van Nieuwerburgh F, Vermeirssen V, Van Neste C, Ghesquiere B, Goossens S, Eyckerman S, De Preter K, Fischer M, Houseley J, Molenaar J, De Wilde B, Roberts SS, Durinck K, Speleman F. RRM2 enhances MYCN-driven neuroblastoma formation and acts as a synergistic target with CHK1 inhibition. SCIENCE ADVANCES 2022; 8:eabn1382. [PMID: 35857500 PMCID: PMC9278860 DOI: 10.1126/sciadv.abn1382] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 05/26/2022] [Indexed: 05/06/2023]
Abstract
High-risk neuroblastoma, a pediatric tumor originating from the sympathetic nervous system, has a low mutation load but highly recurrent somatic DNA copy number variants. Previously, segmental gains and/or amplifications allowed identification of drivers for neuroblastoma development. Using this approach, combined with gene dosage impact on expression and survival, we identified ribonucleotide reductase subunit M2 (RRM2) as a candidate dependency factor further supported by growth inhibition upon in vitro knockdown and accelerated tumor formation in a neuroblastoma zebrafish model coexpressing human RRM2 with MYCN. Forced RRM2 induction alleviates excessive replicative stress induced by CHK1 inhibition, while high RRM2 expression in human neuroblastomas correlates with high CHK1 activity. MYCN-driven zebrafish tumors with RRM2 co-overexpression exhibit differentially expressed DNA repair genes in keeping with enhanced ATR-CHK1 signaling activity. In vitro, RRM2 inhibition enhances intrinsic replication stress checkpoint addiction. Last, combinatorial RRM2-CHK1 inhibition acts synergistic in high-risk neuroblastoma cell lines and patient-derived xenograft models, illustrating the therapeutic potential.
Collapse
Affiliation(s)
- Carolina Nunes
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
- Cancer Research Institute Ghent (CRIG), Ghent, Belgium
| | - Lisa Depestel
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
- Cancer Research Institute Ghent (CRIG), Ghent, Belgium
| | - Liselot Mus
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
- Cancer Research Institute Ghent (CRIG), Ghent, Belgium
| | | | - Louis Delhaye
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
- Cancer Research Institute Ghent (CRIG), Ghent, Belgium
- VIB-UGent Center for Medical Biotechnology, Ghent University, Ghent, Belgium
| | - Amber Louwagie
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
- Cancer Research Institute Ghent (CRIG), Ghent, Belgium
| | - Muhammad Rishfi
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
- Cancer Research Institute Ghent (CRIG), Ghent, Belgium
| | - Alex Whale
- Epigenetics Programme, Babraham Institute, Cambridge, UK
| | - Neesha Kara
- Epigenetics Programme, Babraham Institute, Cambridge, UK
| | | | - Filemon Dela Cruz
- Department of Pediatrics, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Daoqi You
- Department of Pediatrics, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Armaan Siddiquee
- Department of Pediatrics, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Camila Takeno Cologna
- Metabolomics Expertise Center, Center for Cancer Biology (CCB), VIB, Leuven, Belgium
- Metabolomics Expertise Center, Department of Oncology, KU Leuven, Leuven, Belgium
| | - Sam De Craemer
- Metabolomics Expertise Center, Center for Cancer Biology (CCB), VIB, Leuven, Belgium
- Metabolomics Expertise Center, Department of Oncology, KU Leuven, Leuven, Belgium
| | - Emmy Dolman
- Princess Maxima Center, Utrecht, Netherlands
| | - Christoph Bartenhagen
- Center for Molecular Medicine Cologne, Cologne (CMMC), Medical Faculty, University of Cologne, Cologne, Germany
- Department of Experimental Pediatric Oncology, University Children’s Hospital of Cologne, Cologne, Germany
| | - Fanny De Vloed
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
- Cancer Research Institute Ghent (CRIG), Ghent, Belgium
| | - Ellen Sanders
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
- Cancer Research Institute Ghent (CRIG), Ghent, Belgium
| | - Aline Eggermont
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
- Cancer Research Institute Ghent (CRIG), Ghent, Belgium
| | - Sarah-Lee Bekaert
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
| | - Wouter Van Loocke
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
- Cancer Research Institute Ghent (CRIG), Ghent, Belgium
| | - Jan Willem Bek
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
- Cancer Research Institute Ghent (CRIG), Ghent, Belgium
| | - Givani Dewyn
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
- Cancer Research Institute Ghent (CRIG), Ghent, Belgium
| | - Siebe Loontiens
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
- Cancer Research Institute Ghent (CRIG), Ghent, Belgium
| | | | - Bieke Decaesteker
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
- Cancer Research Institute Ghent (CRIG), Ghent, Belgium
| | - Laurentijn Tilleman
- NXTGNT, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium
| | | | - Vanessa Vermeirssen
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
- Cancer Research Institute Ghent (CRIG), Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Christophe Van Neste
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
- Cancer Research Institute Ghent (CRIG), Ghent, Belgium
| | - Bart Ghesquiere
- Metabolomics Expertise Center, Center for Cancer Biology (CCB), VIB, Leuven, Belgium
- Metabolomics Expertise Center, Department of Oncology, KU Leuven, Leuven, Belgium
| | - Steven Goossens
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
- Cancer Research Institute Ghent (CRIG), Ghent, Belgium
- Department of Diagnostic Sciences, Ghent University, Ghent, Belgium
| | - Sven Eyckerman
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
- Cancer Research Institute Ghent (CRIG), Ghent, Belgium
- VIB-UGent Center for Medical Biotechnology, Ghent University, Ghent, Belgium
| | - Katleen De Preter
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
- Cancer Research Institute Ghent (CRIG), Ghent, Belgium
| | - Matthias Fischer
- Center for Molecular Medicine Cologne, Cologne (CMMC), Medical Faculty, University of Cologne, Cologne, Germany
- Department of Experimental Pediatric Oncology, University Children’s Hospital of Cologne, Cologne, Germany
| | - Jon Houseley
- Epigenetics Programme, Babraham Institute, Cambridge, UK
| | | | - Bram De Wilde
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
- Cancer Research Institute Ghent (CRIG), Ghent, Belgium
| | - Stephen S. Roberts
- Department of Pediatrics, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Kaat Durinck
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
- Cancer Research Institute Ghent (CRIG), Ghent, Belgium
| | - Frank Speleman
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
- Cancer Research Institute Ghent (CRIG), Ghent, Belgium
| |
Collapse
|
14
|
Whale AJ, King M, Hull RM, Krueger F, Houseley J. Stimulation of adaptive gene amplification by origin firing under replication fork constraint. Nucleic Acids Res 2022; 50:915-936. [PMID: 35018465 PMCID: PMC8789084 DOI: 10.1093/nar/gkab1257] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 11/26/2021] [Accepted: 12/06/2021] [Indexed: 02/06/2023] Open
Abstract
Adaptive mutations can cause drug resistance in cancers and pathogens, and increase the tolerance of agricultural pests and diseases to chemical treatment. When and how adaptive mutations form is often hard to discern, but we have shown that adaptive copy number amplification of the copper resistance gene CUP1 occurs in response to environmental copper due to CUP1 transcriptional activation. Here we dissect the mechanism by which CUP1 transcription in budding yeast stimulates copy number variation (CNV). We show that transcriptionally stimulated CNV requires TREX-2 and Mediator, such that cells lacking TREX-2 or Mediator respond normally to copper but cannot acquire increased resistance. Mediator and TREX-2 can cause replication stress by tethering transcribed loci to nuclear pores, a process known as gene gating, and transcription at the CUP1 locus causes a TREX-2-dependent accumulation of replication forks indicative of replication fork stalling. TREX-2-dependent CUP1 gene amplification occurs by a Rad52 and Rad51-mediated homologous recombination mechanism that is enhanced by histone H3K56 acetylation and repressed by Pol32 and Pif1. CUP1 amplification is also critically dependent on late-firing replication origins present in the CUP1 repeats, and mutations that remove or inactivate these origins strongly suppress the acquisition of copper resistance. We propose that replicative stress imposed by nuclear pore association causes replication bubbles from these origins to collapse soon after activation, leaving a tract of H3K56-acetylated chromatin that promotes secondary recombination events during elongation after replication fork re-start events. The capacity for inefficient replication origins to promote copy number variation renders certain genomic regions more fragile than others, and therefore more likely to undergo adaptive evolution through de novo gene amplification.
Collapse
Affiliation(s)
- Alex J Whale
- Epigenetics Programme, Babraham Institute, Cambridge, UK
| | - Michelle King
- Epigenetics Programme, Babraham Institute, Cambridge, UK
| | - Ryan M Hull
- Epigenetics Programme, Babraham Institute, Cambridge, UK
| | - Felix Krueger
- Babraham Bioinformatics, Babraham Institute, Cambridge, UK
| | | |
Collapse
|
15
|
Pourali P, Pasero P, Pardo B. Top1p targeting by Fob1p at the ribosomal Replication Fork Barrier does not account for camptothecin sensitivity in Saccharomyces cerevisiae cells. MICROPUBLICATION BIOLOGY 2022; 2022:10.17912/micropub.biology.000514. [PMID: 35071999 PMCID: PMC8771244 DOI: 10.17912/micropub.biology.000514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 01/12/2022] [Accepted: 01/13/2022] [Indexed: 11/23/2022]
Abstract
Camptothecin (CPT) is a specific inhibitor of the DNA topoisomerase I (Top1p), currently used in cancer therapy, which induces DNA damage and cell death. Top1p is highly active at the repeated ribosomal DNA locus (rDNA) to relax DNA supercoiling caused by elevated transcription and replication occurring in opposite directions. Fob1p interacts with, and stabilizes, Top1p at the rDNA Replication Fork Barrier (rRFB), where replication and transcription converge. Here, we have investigated if the absence of Fob1p and the consequent loss of Top1p specific targeting to the rRFB impact the sensitivity and the cell cycle progression of wild-type cells to CPT. We have also investigated the consequences of the absence of Fob1p in rad52∆ mutants, which are affected in the repair of CPT-induced DNA damage by homologous recombination. The results show that CPT sensitivity and the global cell cycle progression in cells exposed to CPT is not changed in the absence of Fob1p. Moreover, we have observed in fob1∆ cells treated with CPT that the homologous recombination factor Rad52p still congregates in the shape of foci in the nucleolus, which hosts the rDNA. This suggests that, in the absence of Fob1p, Top1p is still recruited to the rDNA, presumably at sequences other than the rRFB, and its inhibition by CPT leads to recombination events.
Collapse
Affiliation(s)
- Pardis Pourali
- Institut de Génétique Humaine, Université de Montpellier-CNRS, Montpellier, France
| | - Philippe Pasero
- Institut de Génétique Humaine, Université de Montpellier-CNRS, Montpellier, France
| | - Benjamin Pardo
- Institut de Génétique Humaine, Université de Montpellier-CNRS, Montpellier, France,
Correspondence to: Benjamin Pardo ()
| |
Collapse
|
16
|
Genome-wide mapping of genomic DNA damage: methods and implications. Cell Mol Life Sci 2021; 78:6745-6762. [PMID: 34463773 PMCID: PMC8558167 DOI: 10.1007/s00018-021-03923-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 08/02/2021] [Accepted: 08/11/2021] [Indexed: 12/19/2022]
Abstract
Exposures from the external and internal environments lead to the modification of genomic DNA, which is implicated in the cause of numerous diseases, including cancer, cardiovascular, pulmonary and neurodegenerative diseases, together with ageing. However, the precise mechanism(s) linking the presence of damage, to impact upon cellular function and pathogenesis, is far from clear. Genomic location of specific forms of damage is likely to be highly informative in understanding this process, as the impact of downstream events (e.g. mutation, microsatellite instability, altered methylation and gene expression) on cellular function will be positional—events at key locations will have the greatest impact. However, until recently, methods for assessing DNA damage determined the totality of damage in the genomic location, with no positional information. The technique of “mapping DNA adductomics” describes the molecular approaches that map a variety of forms of DNA damage, to specific locations across the nuclear and mitochondrial genomes. We propose that integrated comparison of this information with other genome-wide data, such as mutational hotspots for specific genotoxins, tumour-specific mutation patterns and chromatin organisation and transcriptional activity in non-cancerous lesions (such as nevi), pre-cancerous conditions (such as polyps) and tumours, will improve our understanding of how environmental toxins lead to cancer. Adopting an analogous approach for non-cancer diseases, including the development of genome-wide assays for other cellular outcomes of DNA damage, will improve our understanding of the role of DNA damage in pathogenesis more generally.
Collapse
|
17
|
Blin M, Lacroix L, Petryk N, Jaszczyszyn Y, Chen CL, Hyrien O, Le Tallec B. DNA molecular combing-based replication fork directionality profiling. Nucleic Acids Res 2021; 49:e69. [PMID: 33836085 PMCID: PMC8266662 DOI: 10.1093/nar/gkab219] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 03/15/2021] [Accepted: 03/19/2021] [Indexed: 01/05/2023] Open
Abstract
The replication strategy of metazoan genomes is still unclear, mainly because definitive maps of replication origins are missing. High-throughput methods are based on population average and thus may exclusively identify efficient initiation sites, whereas inefficient origins go undetected. Single-molecule analyses of specific loci can detect both common and rare initiation events along the targeted regions. However, these usually concentrate on positioning individual events, which only gives an overview of the replication dynamics. Here, we computed the replication fork directionality (RFD) profiles of two large genes in different transcriptional states in chicken DT40 cells, namely untranscribed and transcribed DMD and CCSER1 expressed at WT levels or overexpressed, by aggregating hundreds of oriented replication tracks detected on individual DNA fibres stretched by molecular combing. These profiles reconstituted RFD domains composed of zones of initiation flanking a zone of termination originally observed in mammalian genomes and were highly consistent with independent population-averaging profiles generated by Okazaki fragment sequencing. Importantly, we demonstrate that inefficient origins do not appear as detectable RFD shifts, explaining why dispersed initiation has remained invisible to population-based assays. Our method can both generate quantitative profiles and identify discrete events, thereby constituting a comprehensive approach to study metazoan genome replication.
Collapse
Affiliation(s)
- Marion Blin
- Département de Gastro-entérologie, pôle MAD, Assistance Publique des Hôpitaux de Marseille, Centre Hospitalier Universitaire de Marseille, Marseille, France
| | - Laurent Lacroix
- Institut de Biologie de l’Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, Université PSL, 46 rue d’Ulm, F-75005 Paris, France
| | - Nataliya Petryk
- Institut de Biologie de l’Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, Université PSL, 46 rue d’Ulm, F-75005 Paris, France
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), F-91198 Gif-sur-Yvette, France
| | - Yan Jaszczyszyn
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), F-91198 Gif-sur-Yvette, France
| | - Chun-Long Chen
- Institut Curie, Université PSL, Sorbonne Université, CNRS UMR3244, F-75005 Paris, France
| | - Olivier Hyrien
- Institut de Biologie de l’Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, Université PSL, 46 rue d’Ulm, F-75005 Paris, France
| | - Benoît Le Tallec
- Institut de Biologie de l’Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, Université PSL, 46 rue d’Ulm, F-75005 Paris, France
| |
Collapse
|