1
|
Liang Y, Qu X, Shah NM, Wang T. Towards targeting transposable elements for cancer therapy. Nat Rev Cancer 2024; 24:123-140. [PMID: 38228901 DOI: 10.1038/s41568-023-00653-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/04/2023] [Indexed: 01/18/2024]
Abstract
Transposable elements (TEs) represent almost half of the human genome. Historically deemed 'junk DNA', recent technological advancements have stimulated a wave of research into the functional impact of TEs on gene-regulatory networks in evolution and development, as well as in diseases including cancer. The genetic and epigenetic evolution of cancer involves the exploitation of TEs, whereby TEs contribute directly to cancer-specific gene activities. This Review provides a perspective on the role of TEs in cancer as being a 'double-edged sword', both promoting cancer evolution and representing a vulnerability that could be exploited in cancer therapy. We discuss how TEs affect transcriptome regulation and other cellular processes in cancer. We highlight the potential of TEs as therapeutic targets for cancer. We also summarize technical hurdles in the characterization of TEs with genomic assays. Last, we outline open questions and exciting future research avenues.
Collapse
Affiliation(s)
- Yonghao Liang
- Department of Genetics, Washington University School of Medicine, Saint Louis, MO, USA
- Center for Genome Sciences and Systems Biology, Washington University School of Medicine, Saint Louis, MO, USA
| | - Xuan Qu
- Department of Genetics, Washington University School of Medicine, Saint Louis, MO, USA
- Center for Genome Sciences and Systems Biology, Washington University School of Medicine, Saint Louis, MO, USA
| | - Nakul M Shah
- Division of Cancer Medicine, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Ting Wang
- Department of Genetics, Washington University School of Medicine, Saint Louis, MO, USA.
- Center for Genome Sciences and Systems Biology, Washington University School of Medicine, Saint Louis, MO, USA.
- McDonnell Genome Institute, Washington University School of Medicine, Saint Louis, MO, USA.
| |
Collapse
|
2
|
Bucknell AH, McDonald MC. That's no moon, it's a Starship: Giant transposons driving fungal horizontal gene transfer. Mol Microbiol 2023; 120:555-563. [PMID: 37434470 DOI: 10.1111/mmi.15118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 06/09/2023] [Accepted: 06/13/2023] [Indexed: 07/13/2023]
Abstract
To date, most reports of horizontal gene transfer (HGT) in fungi rely on genome sequence data and are therefore an indirect measure of HGT after the event has occurred. However, a novel group of class II-like transposons known as Starships may soon alter this status quo. Starships are giant transposable elements that carry dozens of genes, some of which are host-beneficial, and are linked to many recent HGT events in the fungal kingdom. These transposons remain active and mobile in many fungal genomes and their transposition has recently been shown to be driven by a conserved tyrosine-recombinase called 'Captain'. This perspective explores some of the remaining unanswered questions about how these Starship transposons move, both within a genome and between different species. We seek to outline several experimental approaches that can be used to identify the genes essential for Starship-mediated HGT and draw links to other recently discovered giant transposons outside of the fungal kingdom.
Collapse
Affiliation(s)
- Angus H Bucknell
- School of Biosciences, Institute of Microbiology and Infection, University of Birmingham, Birmingham, UK
| | - Megan C McDonald
- School of Biosciences, Institute of Microbiology and Infection, University of Birmingham, Birmingham, UK
| |
Collapse
|
3
|
Zhang P, Mbodj A, Soundiramourtty A, Llauro C, Ghesquière A, Ingouff M, Keith Slotkin R, Pontvianne F, Catoni M, Mirouze M. Extrachromosomal circular DNA and structural variants highlight genome instability in Arabidopsis epigenetic mutants. Nat Commun 2023; 14:5236. [PMID: 37640706 PMCID: PMC10462705 DOI: 10.1038/s41467-023-41023-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Accepted: 08/21/2023] [Indexed: 08/31/2023] Open
Abstract
Abundant extrachromosomal circular DNA (eccDNA) is associated with transposable element (TE) activity. However, how the eccDNA compartment is controlled by epigenetic regulations and what is its impact on the genome is understudied. Here, using long reads, we sequence both the eccDNA compartment and the genome of Arabidopsis thaliana mutant plants affected in DNA methylation and post-transcriptional gene silencing. We detect a high load of TE-derived eccDNA with truncated and chimeric forms. On the genomic side, on top of truncated and full length TE neo-insertions, we detect complex structural variations (SVs) notably at a disease resistance cluster being a natural hotspot of SV. Finally, we serendipitously identify large tandem duplications in hypomethylated plants, suggesting that SVs could have been overlooked in epigenetic mutants. We propose that a high eccDNA load may alter DNA repair pathways leading to genome instability and the accumulation of SVs, at least in plants.
Collapse
Affiliation(s)
- Panpan Zhang
- Institut de Recherche pour le Développement (IRD), Laboratory of Plant Genome and Development, Perpignan, France
- EMR269 MANGO (CNRS/IRD/UPVD), Laboratory of Plant Genome and Development, Perpignan, France
- University of Montpellier, Montpellier, France
| | - Assane Mbodj
- Institut de Recherche pour le Développement (IRD), Laboratory of Plant Genome and Development, Perpignan, France
- EMR269 MANGO (CNRS/IRD/UPVD), Laboratory of Plant Genome and Development, Perpignan, France
| | - Abirami Soundiramourtty
- EMR269 MANGO (CNRS/IRD/UPVD), Laboratory of Plant Genome and Development, Perpignan, France
- University of Perpignan, Perpignan, France
| | - Christel Llauro
- EMR269 MANGO (CNRS/IRD/UPVD), Laboratory of Plant Genome and Development, Perpignan, France
- Centre National de la Recherche Scientifique (CNRS), Laboratory of Plant Genome and Development, Perpignan, France
| | - Alain Ghesquière
- DIADE, University of Montpellier, IRD, CIRAD, Montpellier, France
| | - Mathieu Ingouff
- DIADE, University of Montpellier, IRD, CIRAD, Montpellier, France
| | - R Keith Slotkin
- Donald Danforth Plant Science Center, St. Louis, MO, 63132, USA
- Division of Biological Sciences, University of Missouri, Columbia, MO, 65211, USA
| | - Frédéric Pontvianne
- Centre National de la Recherche Scientifique (CNRS), Laboratory of Plant Genome and Development, Perpignan, France
| | - Marco Catoni
- School of Biosciences, University of Birmingham, Birmingham, B15 2TT, UK
| | - Marie Mirouze
- Institut de Recherche pour le Développement (IRD), Laboratory of Plant Genome and Development, Perpignan, France.
- EMR269 MANGO (CNRS/IRD/UPVD), Laboratory of Plant Genome and Development, Perpignan, France.
| |
Collapse
|
4
|
Yang F, Su W, Chung OW, Tracy L, Wang L, Ramsden DA, Zhang ZZZ. Retrotransposons hijack alt-EJ for DNA replication and eccDNA biogenesis. Nature 2023; 620:218-225. [PMID: 37438532 PMCID: PMC10691919 DOI: 10.1038/s41586-023-06327-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 06/14/2023] [Indexed: 07/14/2023]
Abstract
Retrotransposons are highly enriched in the animal genome1-3. The activation of retrotransposons can rewrite host DNA information and fundamentally impact host biology1-3. Although developmental activation of retrotransposons can offer benefits for the host, such as against virus infection, uncontrolled activation promotes disease or potentially drives ageing1-5. After activation, retrotransposons use their mRNA as templates to synthesize double-stranded DNA for making new insertions in the host genome1-3,6. Although the reverse transcriptase that they encode can synthesize the first-strand DNA1-3,6, how the second-strand DNA is generated remains largely unclear. Here we report that retrotransposons hijack the alternative end-joining (alt-EJ) DNA repair process of the host for a circularization step to synthesize their second-strand DNA. We used Nanopore sequencing to examine the fates of replicated retrotransposon DNA, and found that 10% of them achieve new insertions, whereas 90% exist as extrachromosomal circular DNA (eccDNA). Using eccDNA production as a readout, further genetic screens identified factors from alt-EJ as essential for retrotransposon replication. alt-EJ drives the second-strand synthesis of the long terminal repeat retrotransposon DNA through a circularization process and is therefore necessary for eccDNA production and new insertions. Together, our study reveals that alt-EJ is essential in driving the propagation of parasitic genomic retroelements. Our study uncovers a conserved function of this understudied DNA repair process, and provides a new perspective to understand-and potentially control-the retrotransposon life cycle.
Collapse
Affiliation(s)
- Fu Yang
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, NC, USA
| | - Weijia Su
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, NC, USA
| | - Oliver W Chung
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, NC, USA
| | - Lauren Tracy
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, NC, USA
| | - Lu Wang
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, NC, USA
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China
| | - Dale A Ramsden
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Z Z Zhao Zhang
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, NC, USA.
- Duke Regeneration Center, Duke University School of Medicine, Durham, NC, USA.
| |
Collapse
|
5
|
Joubert PM, Krasileva KV. The extrachromosomal circular DNAs of the rice blast pathogen Magnaporthe oryzae contain a wide variety of LTR retrotransposons, genes, and effectors. BMC Biol 2022; 20:260. [PMID: 36424609 PMCID: PMC9694575 DOI: 10.1186/s12915-022-01457-2] [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: 10/04/2022] [Accepted: 11/03/2022] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND One of the ways genomes respond to stress is by producing extrachromosomal circular DNAs (eccDNAs). EccDNAs can contain genes and dramatically increase their copy number. They can also reinsert into the genome, generating structural variation. They have been shown to provide a source of phenotypic and genotypic plasticity in several species. However, whole circularome studies have so far been limited to a few model organisms. Fungal plant pathogens are a serious threat to global food security in part because of their rapid adaptation to disease prevention strategies. Understanding the mechanisms fungal pathogens use to escape disease control is paramount to curbing their threat. RESULTS We present a whole circularome sequencing study of the rice blast pathogen, Magnaporthe oryzae. We find that M. oryzae has a highly diverse circularome that contains many genes and shows evidence of large LTR retrotransposon activity. We find that genes enriched on eccDNAs in M. oryzae occur in genomic regions prone to presence-absence variation and that disease-associated genes are frequently on eccDNAs. Finally, we find that a subset of genes is never present on eccDNAs in our data, which indicates that the presence of these genes on eccDNAs is selected against. CONCLUSIONS Our study paves the way to understanding how eccDNAs contribute to adaptation in M. oryzae. Our analysis also reveals how M. oryzae eccDNAs differ from those of other species and highlights the need for further comparative characterization of eccDNAs across species to gain a better understanding of these molecules.
Collapse
Affiliation(s)
- Pierre M Joubert
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720, USA.
| | - Ksenia V Krasileva
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720, USA.
| |
Collapse
|
6
|
Li F, Yang L, Han J, Han X, Peng L, Du Y, Xia H, Yang L, Zhou Y. Characterization of extrachromosomal circular DNA in cattle using 676 whole genome sequencing datasets. Anim Genet 2022; 53:761-768. [PMID: 36226728 DOI: 10.1111/age.13269] [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: 09/22/2022] [Revised: 09/22/2022] [Accepted: 09/24/2022] [Indexed: 11/28/2022]
Abstract
Extrachromosomal circular DNA (eccDNA) is an important fraction of the genome. Recent studies proved that eccDNA plays important roles in genetic variation, aging and environmental adaptation, which have drawn wide attention. However, the characteristics of eccDNA in cattle remain unclear. Here, we studied eccDNAs from 676 cattle of 58 breeds using whole genome sequencing datasets. In total, 47 355 high-confidence eccDNAs were identified and covered 4.6% of the cattle autosomes in length. Similarly to other species, the cattle eccDNA preferentially located in the genic and repeat sequences. Cattle eccDNAs contained complete sequences of 661 genes, which were significantly (p < 0.05) enriched in immunity-related functions. The eccDNA was further proved to have inverted repeats on the boundaries, which contained a high proportion of A/T and ranged from 4 to 17 bp. Interestingly, we successfully separated animals according to their geographical distributions and their tissues where DNA was isolated. This implied possible roles for eccDNA in cattle selection and tissue development. Our study supplies basic knowledges on eccDNAs in cattle, which will promote understanding of extrachromosomal DNA.
Collapse
Affiliation(s)
- Fan Li
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan, China
| | - Lv Yang
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan, China
| | - Jiazheng Han
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan, China
| | - Xiaotao Han
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan, China
| | - Lingwei Peng
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan, China
| | - Yuqin Du
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan, China
| | - Han Xia
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan, China
| | - Liguo Yang
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan, China.,National Center for International Research on Animal Genetics, Breeding and Reproduction, Huazhong Agricultural University, Wuhan, China.,Frontiers Science Center for Animal Breeding and Sustainable Production, Huazhong Agricultural University, Wuhan, China
| | - Yang Zhou
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan, China.,National Center for International Research on Animal Genetics, Breeding and Reproduction, Huazhong Agricultural University, Wuhan, China.,Frontiers Science Center for Animal Breeding and Sustainable Production, Huazhong Agricultural University, Wuhan, China
| |
Collapse
|
7
|
Li R, Wang Y, Li J, Zhou X. Extrachromosomal circular DNA (eccDNA): an emerging star in cancer. Biomark Res 2022; 10:53. [PMID: 35883211 PMCID: PMC9327165 DOI: 10.1186/s40364-022-00399-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Accepted: 07/13/2022] [Indexed: 02/08/2023] Open
Abstract
Extrachromosomal circular DNA (eccDNA) is defined as a type of circular DNA that exists widely in nature and is independent of chromosomes. EccDNA has attracted the attention of researchers due to its broad, random distribution, complex biogenesis and tumor-relevant functions. EccDNA can carry complete gene information, especially the oncogenic driver genes that are often carried in tumors, with increased copy number and high transcriptional activity. The high overexpression of oncogenes by eccDNA leads to malignant growth of tumors. Regardless, the exact generation and functional mechanisms of eccDNA in disease progression are not yet clear. There is, however, an emerging body of evidence characterizing that eccDNA can be generated from multiple pathways, including DNA damage repair pathways, breakage-fusion-bridge (BFB) mechanisms, chromothripsis and cell apoptosis, and participates in the regulation of tumor progression with multiplex functions. This up-to-date review summarizes and discusses the origins, biogenesis and functions of eccDNA, including its contribution to the formation of oncogene instability and mutations, the heterogeneity and cellular senescence of tumor cells, and the proinflammatory response of tumors. We highlight the possible cancer-related applications of eccDNA, such as its potential use in the diagnosis, targeted therapy and prognostic assessment of cancer.
Collapse
Affiliation(s)
- Ruomeng Li
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu, 610041, China.,State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Chinese Academy of Medical Sciences Research Unit of Oral Carcinogenesis and Management, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, 610041, PR China
| | - Ying Wang
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Chinese Academy of Medical Sciences Research Unit of Oral Carcinogenesis and Management, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, 610041, PR China
| | - Jing Li
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Chinese Academy of Medical Sciences Research Unit of Oral Carcinogenesis and Management, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, 610041, PR China.
| | - Xikun Zhou
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu, 610041, China.
| |
Collapse
|
8
|
Kwolek K, Kędzierska P, Hankiewicz M, Mirouze M, Panaud O, Grzebelus D, Macko‐Podgórni A. Diverse and mobile: eccDNA-based identification of carrot low-copy-number LTR retrotransposons active in callus cultures. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2022; 110:1811-1828. [PMID: 35426957 PMCID: PMC9324142 DOI: 10.1111/tpj.15773] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 03/15/2022] [Accepted: 03/29/2022] [Indexed: 05/28/2023]
Abstract
Long terminal repeat retrotransposons (LTR-RTs) are mobilized via an RNA intermediate using a 'copy and paste' mechanism, and account for the majority of repetitive DNA in plant genomes. As a side effect of mobilization, the formation of LTR-RT-derived extrachromosomal circular DNAs (eccDNAs) occurs. Thus, high-throughput sequencing of eccDNA can be used to identify active LTR-RTs in plant genomes. Despite the release of a reference genome assembly, carrot LTR-RTs have not yet been thoroughly characterized. LTR-RTs are abundant and diverse in the carrot genome. We identified 5976 carrot LTR-RTs, 2053 and 1660 of which were attributed to Copia and Gypsy superfamilies, respectively. They were further classified into lineages, families and subfamilies. More diverse LTR-RT lineages, i.e. lineages comprising many low-copy-number subfamilies, were more frequently associated with genic regions. Certain LTR-RT lineages have been recently active in Daucus carota. In particular, low-copy-number LTR-RT subfamilies, e.g. those belonging to the DcAle lineage, have significantly contributed to carrot genome diversity as a result of continuing activity. We utilized eccDNA sequencing to identify and characterize two DcAle subfamilies, Alex1 and Alex3, active in carrot callus. We documented 14 and 32 de novo insertions of Alex1 and Alex3, respectively, which were positioned in non-repetitive regions.
Collapse
Affiliation(s)
- Kornelia Kwolek
- Department of Plant Biology and Biotechnology, Faculty of Biotechnology and HorticultureUniversity of Agriculture in Krakow31 120KrakowPoland
| | - Patrycja Kędzierska
- Department of Plant Biology and Biotechnology, Faculty of Biotechnology and HorticultureUniversity of Agriculture in Krakow31 120KrakowPoland
| | - Magdalena Hankiewicz
- Department of Plant Biology and Biotechnology, Faculty of Biotechnology and HorticultureUniversity of Agriculture in Krakow31 120KrakowPoland
| | - Marie Mirouze
- Laboratoire Génome et Développement des Plantes, UMR 5096 CNRS/UPVDUniversité de PerpignanVia Domitia, 52 Avenue Paul Alduy66 860Perpignan CedexFrance
- IRD, EMR IRD‐CNRS‐UPVD ‘MANGO’Université de PerpignanPerpignanFrance
| | - Olivier Panaud
- Laboratoire Génome et Développement des Plantes, UMR 5096 CNRS/UPVDUniversité de PerpignanVia Domitia, 52 Avenue Paul Alduy66 860Perpignan CedexFrance
| | - Dariusz Grzebelus
- Department of Plant Biology and Biotechnology, Faculty of Biotechnology and HorticultureUniversity of Agriculture in Krakow31 120KrakowPoland
| | - Alicja Macko‐Podgórni
- Department of Plant Biology and Biotechnology, Faculty of Biotechnology and HorticultureUniversity of Agriculture in Krakow31 120KrakowPoland
| |
Collapse
|
9
|
Peng L, Zhou N, Zhang CY, Li GC, Yuan XQ. eccDNAdb: a database of extrachromosomal circular DNA profiles in human cancers. Oncogene 2022; 41:2696-2705. [PMID: 35388171 PMCID: PMC9076536 DOI: 10.1038/s41388-022-02286-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 03/09/2022] [Accepted: 03/17/2022] [Indexed: 12/26/2022]
Abstract
Extrachromosomal circular DNA (eccDNA) elements are circular DNA molecules that are derived from but are independent of chromosomal DNA. EccDNA is emerging as a rising star because of its ubiquitous existence in cancers and its crucial role in oncogene amplification and tumor progression. In the present study, whole-genome sequencing (WGS) data of cancer samples were downloaded from public repositories. Afterwards, eccDNAs were identified from WGS data via bioinformatic analyses. To leverage database coverage, eccDNAs were also collected by manual curation of literatures. Gene expression and clinical data were downloaded from TCGA and CCLE and then used to investigate the roles of eccDNAs in cancers. Finally, the first integrated database of eccDNAs, eccDNAdb, was developed. eccDNAdb currently includes 1270 eccDNAs, which were identified in 480 samples (of 42 cancers) after analyzing a total number of 3395 tumor samples (of 57 cancers) including patient tissues, patient-derived xenografts, and cancer cell lines. A total number of 54,901 eccDNA genes were annotated and included in the database as well. With the integration of gene expression, clinical information and chromatin accessibility data, eccDNAdb enables users to easily determine the biological function and clinical relevance of eccDNAs in human cancers. In conclusion, eccDNAdb is freely accessible at http://www.eccdnadb.org . To our knowledge, eccDNAdb is the first database in the eccDNA research field. It is expected to provide insight for novel cancer therapies.
Collapse
Affiliation(s)
- Li Peng
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Guangdong-Hong Kong Joint Laboratory for RNA Medicine, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China. .,Medical Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China.
| | - Nan Zhou
- Department of Research, The Affiliated Brain Hospital of Guangzhou Medical University, Guangzhou, China.,Guangdong Engineering Technology Research Center for Translational Medicine of Mental Disorders, Guangzhou, China
| | - Chao-Yang Zhang
- Division of Functional Genome Analysis, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Guan-Cheng Li
- Key Laboratory of Carcinogenesis of the Chinese Ministry of Health and the Key Laboratory of Carcinogenesis and Cancer Invasion of Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, China
| | - Xiao-Qing Yuan
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Guangdong-Hong Kong Joint Laboratory for RNA Medicine, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China. .,Breast Tumor Center, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, 510120, China.
| |
Collapse
|
10
|
Yang H, He J, Huang S, Yang H, Yi Q, Tao Y, Chen M, Zhang X, Qi H. Identification and Characterization of Extrachromosomal Circular DNA in Human Placentas With Fetal Growth Restriction. Front Immunol 2022; 12:780779. [PMID: 34992600 PMCID: PMC8724250 DOI: 10.3389/fimmu.2021.780779] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 11/29/2021] [Indexed: 12/13/2022] Open
Abstract
Many studies have confirmed that extrachromosomal circular DNAs (eccDNAs/ecDNAs) exist in tumor and normal cells independently of the chromosome and are essential for oncogene plasticity and drug resistance. Studies have confirmed that there are many eccDNAs/ecDNAs in maternal plasma derived from the fetus. Fetal growth restriction (FGR) is a pregnancy-related disease associated with high newborn morbidity and mortality. However, the characteristics and nature of eccDNAs/ecDNAs in FGR are poorly understood. This study aims to deconstruct the properties and potential functions of eccDNAs/ecDNAs in FGR. We performed circle-seq to identify the expression profile of eccDNAs/ecDNAs, analyzed by bioinformatics, and verified by real-time Polymerase Chain Reaction (PCR) combined with southern blot in FGR compared with the normal groups. A total of 45,131 eccDNAs/ecDNAs (including 2,118 unique ones) were identified, which had significantly higher abundance in FRG group than in normal group, and was bimodal in length, peaking at ~146bp and ~340bp, respectively. Gestational age may be one independent factor affecting the production of eccDNAs/ecDNAs, most of which come from genomic regions with high gene density, with a 4~12bp repeat around the junction, and their origin had a certain genetic preference. In addition, some of the host-genes overlapped with non-coding RNAs (ncRNAs) partially or even completely. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis revealed that host-genes on the differentially expressed eccDNAs/ecDNAs (DEEECs/DEECs) were mainly enriched in immune-related functions and pathways. The presence of some ecDNAs were verified, and whose variability were consistent with the circle-seq results. We identified and characterized eccDNAs/ecDNAs in placentas with FGR, and elucidated the formation mechanisms and the networks with ncRNAs, which provide a new vision for the screening of new biomarkers and therapeutic targets for FGR.
Collapse
Affiliation(s)
- Huan Yang
- Department of Obstetrics, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China.,Department of Obstetrics, Chongqing University Three Gorges Hospital, Chongqing, China.,Chongqing Key Laboratory of Maternal and Fetal Medicine, Chongqing Medical University, Chongqing, China.,China-Canada-New Zealand Joint International Research Laboratory of Reproduction and Development of Chinese Ministry of Education, Chongqing Medical University, Chongqing, China
| | - Jie He
- Department of Obstetrics, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China.,Chongqing Key Laboratory of Maternal and Fetal Medicine, Chongqing Medical University, Chongqing, China.,China-Canada-New Zealand Joint International Research Laboratory of Reproduction and Development of Chinese Ministry of Education, Chongqing Medical University, Chongqing, China
| | - Shuai Huang
- Department of Obstetrics, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China.,Chongqing Key Laboratory of Maternal and Fetal Medicine, Chongqing Medical University, Chongqing, China.,China-Canada-New Zealand Joint International Research Laboratory of Reproduction and Development of Chinese Ministry of Education, Chongqing Medical University, Chongqing, China
| | - Hongbing Yang
- Department of Obstetrics, Chongqing University Three Gorges Hospital, Chongqing, China
| | - Qingjie Yi
- Department of Obstetrics, Chongqing University Three Gorges Hospital, Chongqing, China.,Department of Epidemiology and Health Statistics, School of Public Health and Management, Chongqing Medical University, Chongqing, China
| | - Yuelan Tao
- Department of Obstetrics, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China.,Chongqing Key Laboratory of Maternal and Fetal Medicine, Chongqing Medical University, Chongqing, China.,China-Canada-New Zealand Joint International Research Laboratory of Reproduction and Development of Chinese Ministry of Education, Chongqing Medical University, Chongqing, China
| | - Miaomiao Chen
- Department of Obstetrics, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China.,Chongqing Key Laboratory of Maternal and Fetal Medicine, Chongqing Medical University, Chongqing, China.,China-Canada-New Zealand Joint International Research Laboratory of Reproduction and Development of Chinese Ministry of Education, Chongqing Medical University, Chongqing, China
| | - Xuemei Zhang
- Department of Obstetrics, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China.,Chongqing Key Laboratory of Maternal and Fetal Medicine, Chongqing Medical University, Chongqing, China.,China-Canada-New Zealand Joint International Research Laboratory of Reproduction and Development of Chinese Ministry of Education, Chongqing Medical University, Chongqing, China
| | - Hongbo Qi
- Department of Obstetrics, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China.,Chongqing Key Laboratory of Maternal and Fetal Medicine, Chongqing Medical University, Chongqing, China.,China-Canada-New Zealand Joint International Research Laboratory of Reproduction and Development of Chinese Ministry of Education, Chongqing Medical University, Chongqing, China
| |
Collapse
|
11
|
Fan W, Wang L, Chu J, Li H, Kim EY, Cho J. Tracing Mobile DNAs: From Molecular to Population Scales. FRONTIERS IN PLANT SCIENCE 2022; 13:837378. [PMID: 35178063 PMCID: PMC8843828 DOI: 10.3389/fpls.2022.837378] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 01/11/2022] [Indexed: 06/14/2023]
Abstract
Transposable elements (TEs, transposons) are mobile DNAs that are prevalent in most eukaryotic genomes. In plants, their mobility has vastly contributed to genetic diversity which is essential for adaptive changes and evolution of a species. Such mobile nature of transposon has been also actively exploited in plant science research by generating genetic mutants in non-model plant systems. On the other hand, transposon mobilization can bring about detrimental effects to host genomes and they are therefore mostly silenced by the epigenetic mechanisms. TEs have been studied as major silencing targets and acted a main feature in the remarkable growth of the plant epigenetics field. Despite the importance of transposon in plant biology and biotechnology, their mobilization and the underlying mechanisms are largely left unanswered. This is mainly because of the sequence repetitiveness of transposons, which makes their detection and analyses difficult and complicated. Recently, some attempts have been made to develop new experimental methods detecting active transposons and their mobilization behavior. These techniques reveal TE mobility in various levels, including the molecular, cellular, organismal and population scales. In this review, we will highlight the novel technical approaches in the study of mobile genetic elements and discuss how these techniques impacted on the advancement of transposon research and broadened our understanding of plant genome plasticity.
Collapse
Affiliation(s)
- Wenwen Fan
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Ling Wang
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Jie Chu
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Hui Li
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Eun Yu Kim
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Jungnam Cho
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
- CAS-JIC Centre of Excellence for Plant and Microbial Science, Chinese Academy of Sciences, Shanghai, China
| |
Collapse
|
12
|
Zuo S, Yi Y, Wang C, Li X, Zhou M, Peng Q, Zhou J, Yang Y, He Q. Extrachromosomal Circular DNA (eccDNA): From Chaos to Function. Front Cell Dev Biol 2022; 9:792555. [PMID: 35083218 PMCID: PMC8785647 DOI: 10.3389/fcell.2021.792555] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2021] [Accepted: 12/16/2021] [Indexed: 11/15/2022] Open
Abstract
Extrachromosomal circular DNA (eccDNA) is a type of double-stranded circular DNA that is derived and free from chromosomes. It has a strong heterogeneity in sequence, length, and origin and has been identified in both normal and cancer cells. Although many studies suggested its potential roles in various physiological and pathological procedures including aging, telomere and rDNA maintenance, drug resistance, and tumorigenesis, the functional relevance of eccDNA remains to be elucidated. Recently, due to technological advancements, accumulated evidence highlighted that eccDNA plays an important role in cancers by regulating the expression of oncogenes, chromosome accessibility, genome replication, immune response, and cellular communications. Here, we review the features, biogenesis, physiological functions, potential functions in cancer, and research methods of eccDNAs with a focus on some open problems in the field and provide a perspective on how eccDNAs evolve specific functions out of the chaos in cells.
Collapse
Affiliation(s)
- Shanru Zuo
- Department of Pharmacy, The Third Xiangya Hospital, Central South University, Changsha, China.,The Key Laboratory of Model Animals and Stem Cell Biology in Hunan Province, School of Medicine, Hunan Normal University, Changsha, China
| | - Yihu Yi
- Department of Orthopaedics, Wuhan Union Hospital, Wuhan, China
| | - Chen Wang
- Department of Obstetrics and Gynecology, The Third Xiangya Hospital of Central South University, Changsha, China
| | - Xueguang Li
- The Key Laboratory of Model Animals and Stem Cell Biology in Hunan Province, School of Medicine, Hunan Normal University, Changsha, China
| | - Mingqing Zhou
- Zhongshan Hospital Affiliated to Sun Yat-Sen University, Zhongshan People's Hospital, Zhongshan, China
| | - Qiyao Peng
- Institute of Chinese Medicine, Hunan Academy of Traditional Chinese Medicine and Innovation Centre for Science and Technology, Hunan University of Chinese Medicine, Changsa, China.,Chongqing Key Laboratory for Pharmaceutical Metabolism Research, College of Pharmacy, College of Traditional Chinese Medicine, Chongqing Medical University, Chongqing, China
| | - Junhua Zhou
- The Key Laboratory of Model Animals and Stem Cell Biology in Hunan Province, School of Medicine, Hunan Normal University, Changsha, China
| | - Yide Yang
- The Key Laboratory of Model Animals and Stem Cell Biology in Hunan Province, School of Medicine, Hunan Normal University, Changsha, China
| | - Quanyuan He
- The Key Laboratory of Model Animals and Stem Cell Biology in Hunan Province, School of Medicine, Hunan Normal University, Changsha, China
| |
Collapse
|
13
|
Ling X, Han Y, Meng J, Zhong B, Chen J, Zhang H, Qin J, Pang J, Liu L. Small extrachromosomal circular DNA (eccDNA): major functions in evolution and cancer. Mol Cancer 2021; 20:113. [PMID: 34479546 PMCID: PMC8414719 DOI: 10.1186/s12943-021-01413-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 08/22/2021] [Indexed: 12/13/2022] Open
Abstract
Extrachromosomal circular DNA (eccDNA) refers to a type of circular DNA that originate from but are likely independent of chromosomes. Due to technological advancements, eccDNAs have recently emerged as multifunctional molecules with numerous characteristics. The unique topological structure and genetic characteristics of eccDNAs shed new light on the monitoring, early diagnosis, treatment, and prediction of cancer. EccDNAs are commonly observed in both normal and cancer cells and function via different mechanisms in the stress response to exogenous and endogenous stimuli, aging, and carcinogenesis and in drug resistance during cancer treatment. The structural diversity of eccDNAs contributes to the function and numerical diversity of eccDNAs and thereby endows eccDNAs with powerful roles in evolution and in cancer initiation and progression by driving genetic plasticity and heterogeneity from extrachromosomal sites, which has been an ignored function in evolution in recent decades. EccDNAs show great potential in cancer, and we summarize the features, biogenesis, evaluated functions, functional mechanisms, related methods, and clinical utility of eccDNAs with a focus on their role in evolution and cancer.
Collapse
Affiliation(s)
- Xiaoxuan Ling
- Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan, 523808, P.R. China
| | - Yali Han
- Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan, 523808, P.R. China
| | - Jinxue Meng
- Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan, 523808, P.R. China
| | - Bohuan Zhong
- Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan, 523808, P.R. China
| | - Jialong Chen
- Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan, 523808, P.R. China.,Department of Preventive Medicine, School of Public Health, Guangdong Medical University, Dongguan, 523808, P.R. China
| | - He Zhang
- Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan, 523808, P.R. China.,Department of Preventive Medicine, School of Public Health, Guangdong Medical University, Dongguan, 523808, P.R. China
| | - Jiheng Qin
- Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan, 523808, P.R. China
| | - Jing Pang
- Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan, 523808, P.R. China
| | - Linhua Liu
- Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan, 523808, P.R. China. .,Department of Preventive Medicine, School of Public Health, Guangdong Medical University, Dongguan, 523808, P.R. China.
| |
Collapse
|
14
|
Darphorn TS, Hu Y, Koenders-van Sintanneland BB, Brul S, ter Kuile BH. Multiplication of ampC upon Exposure to a Beta-Lactam Antibiotic Results in a Transferable Transposon in Escherichia coli. Int J Mol Sci 2021; 22:ijms22179230. [PMID: 34502136 PMCID: PMC8430887 DOI: 10.3390/ijms22179230] [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: 07/26/2021] [Revised: 08/23/2021] [Accepted: 08/24/2021] [Indexed: 11/16/2022] Open
Abstract
Plasmids play a crucial role in spreading antimicrobial resistance genes. Plasmids have many ways to incorporate various genes. By inducing amoxicillin resistance in Escherichia coli, followed by horizontal gene transfer experiments and sequencing, we show that the chromosomal beta-lactamase gene ampC is multiplied and results in an 8–13 kb contig. This contig is comparable to a transposon, showing similarities to variable regions found in environmental plasmids, and can be transferred between E. coli cells. As in eight out of nine replicate strains an almost completely identical transposon was isolated, we conclude that this process is under strict control by the cell. The single transposon that differed was shortened at both ends, but otherwise identical. The outcome of this study indicates that as a result of exposure to beta-lactam antibiotics, E. coli can form a transposon containing ampC that can subsequently be integrated into plasmids or genomes. This observation offers an explanation for the large diversity of genes in plasmids found in nature and proposes mechanisms by which the dynamics of plasmids are maintained.
Collapse
Affiliation(s)
- Tania S. Darphorn
- Laboratory for Molecular Biology and Microbial Food Safety, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands; (T.S.D.); (Y.H.); (B.B.K.-v.S.); (S.B.)
| | - Yuanqing Hu
- Laboratory for Molecular Biology and Microbial Food Safety, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands; (T.S.D.); (Y.H.); (B.B.K.-v.S.); (S.B.)
- School of Biological Science and Biotechnology, Minnan Normal University, Zhangzhou 363000, China
| | - Belinda B. Koenders-van Sintanneland
- Laboratory for Molecular Biology and Microbial Food Safety, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands; (T.S.D.); (Y.H.); (B.B.K.-v.S.); (S.B.)
| | - Stanley Brul
- Laboratory for Molecular Biology and Microbial Food Safety, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands; (T.S.D.); (Y.H.); (B.B.K.-v.S.); (S.B.)
| | - Benno H. ter Kuile
- Laboratory for Molecular Biology and Microbial Food Safety, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands; (T.S.D.); (Y.H.); (B.B.K.-v.S.); (S.B.)
- The Netherlands Food and Consumer Product Safety Authority, Office for Risk Assessment, Catharijnesingel 59, 3511 GG Utrecht, The Netherlands
- Correspondence: ; Tel.: +31-6-46596684
| |
Collapse
|
15
|
Su Z, Saha S, Paulsen T, Kumar P, Dutta A. ATAC-Seq-based Identification of Extrachromosomal Circular DNA in Mammalian Cells and Its Validation Using Inverse PCR and FISH. Bio Protoc 2021; 11:e4003. [PMID: 34124304 DOI: 10.21769/bioprotoc.4003] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 02/19/2021] [Accepted: 02/23/2021] [Indexed: 01/11/2023] Open
Abstract
Recent studies from multiple labs including ours have demonstrated the importance of extrachromosomal circular DNA (eccDNA) from yeast to humans ( Shibata et al., 2012 ; Dillon et al., 2015 ; Møller et al., 2016 ; Kumar et al., 2017 ; Turner et al., 2017 ; Kim et al., 2020 ). More recently, it has been found that cancer cells obtain a selective advantage by amplifying oncogenes on eccDNA, which drives genomic instability ( Wu et al., 2019 ; Kim et al., 2020 ). Previously, we have purified circular DNA and enriched the population using rolling circle amplification followed by high-throughput sequencing for the identification of eccDNA based on the unique junctional sequence. However, eccDNA identification by rolling circle amplification is biased toward small circles. Here, we report a rolling circle-independent method to detect eccDNA in human cancer cells. We demonstrate a sensitive and robust step-by-step workflow for finding novel eccDNAs using ATAC-seq (Assay for Transposase-Accessible Chromatin using sequencing) combined with a Circle_finder bioinformatics algorithm to predict the eccDNAs, followed by its validation using two independent methods, inverse PCR and metaphase FISH (Fluorescence in situ Hybridization).
Collapse
Affiliation(s)
- Zhangli Su
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Shekhar Saha
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Teressa Paulsen
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Pankaj Kumar
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Anindya Dutta
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| |
Collapse
|
16
|
Deciphering extrachromosomal circular DNA in Arabidopsis. Comput Struct Biotechnol J 2021; 19:1176-1183. [PMID: 33680359 PMCID: PMC7899950 DOI: 10.1016/j.csbj.2021.01.043] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 01/27/2021] [Accepted: 01/30/2021] [Indexed: 11/23/2022] Open
Abstract
743 eccDNAs were detected in Arabidopsis leaf, flower, stem and root tissues. A large number of tRNAs and transposons were hosted by the eccDNAs. eccDNAs have inverted repeats at upstream and downstream of the boundaries.
Extrachromosomal circular DNA (eccDNA) is independent of the chromosome and exists in many eukaryotes. However, the nature and origin of eccDNA in plants remains unclear. In this study, we sequenced 12 samples from four tissues (leaf, flower, stem and root) with three biological replicates. In total, we found 743 eccDNAs found in at least two samples. Most of eccDNA have inverted repeats ranging from 4 to 12 bp in the boundaries. Interestingly, eccDNA is not only related to transposon activity, but also hosts tRNA genes, suggesting that the eccDNAs may be associated with tRNA abundance which controls protein synthesis under conditions of stress. Our results provide an unprecedented view of eccDNA, which is still naïve in scope.
Collapse
|
17
|
Molin WT, Patterson EL, Saski CA. Homogeneity among glyphosate-resistant Amaranthus palmeri in geographically distant locations. PLoS One 2020; 15:e0233813. [PMID: 32903277 PMCID: PMC7480871 DOI: 10.1371/journal.pone.0233813] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 08/10/2020] [Indexed: 02/06/2023] Open
Abstract
Since the initial report of glyphosate-resistant (GR) Amaranthus palmeri S. Watson in 2006, resistant populations have been reported in 28 states. The mechanism of resistance is amplification of a 399-kb extrachromosomal circular DNA, called the EPSPS replicon, and is unique to glyphosate-resistant plants. The replicon contains a single copy of the 10-kb 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene which causes the concomitant increased expression of EPSP synthase, the target enzyme of glyphosate. It is not known whether the resistance by this amplification mechanism evolved once and then spread across the country or evolved independently in several locations. To compare genomic representation and variation across the EPSPS replicon, whole genome shotgun sequencing (WGS) and mapping of sequences from both GR and susceptible (GS) biotypes to the replicon consensus sequence was performed. Sampling of GR biotypes from AZ, KS, GA, MD and DE and GS biotypes from AZ, KS and GA revealed complete contiguity and deep representation with sequences from GR plants, but lack of homogeneity and contiguity with breaks in coverage were observed with sequences from GS biotypes. The high sequence conservation among GR biotypes with very few polymorphisms which were widely distributed across the USA further supports the hypothesis that glyphosate resistance most likely originated from a single population. We show that the replicon from different populations was unique to GR plants and had similar levels of amplification.
Collapse
Affiliation(s)
- William T. Molin
- Crop Production Systems Research Unit, United States Department of Agriculture, Stoneville, Mississippi, United States of America
| | - Eric L. Patterson
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, Michigan, United States of America
| | - Christopher A. Saski
- Department of Plant and Environmental Sciences, Clemson University, Clemson, South Carolina, United States of America
| |
Collapse
|
18
|
Prada-Luengo I, Møller HD, Henriksen RA, Gao Q, Larsen C, Alizadeh S, Maretty L, Houseley J, Regenberg B. Replicative aging is associated with loss of genetic heterogeneity from extrachromosomal circular DNA in Saccharomyces cerevisiae. Nucleic Acids Res 2020; 48:7883-7898. [PMID: 32609810 PMCID: PMC7430651 DOI: 10.1093/nar/gkaa545] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Revised: 05/28/2020] [Accepted: 06/17/2020] [Indexed: 12/26/2022] Open
Abstract
Circular DNA can arise from all parts of eukaryotic chromosomes. In yeast, circular ribosomal DNA (rDNA) accumulates dramatically as cells age, however little is known about the accumulation of other chromosome-derived circles or the contribution of such circles to genetic variation in aged cells. We profiled circular DNA in Saccharomyces cerevisiae populations sampled when young and after extensive aging. Young cells possessed highly diverse circular DNA populations but 94% of the circular DNA were lost after ∼15 divisions, whereas rDNA circles underwent massive accumulation to >95% of circular DNA. Circles present in both young and old cells were characterized by replication origins including circles from unique regions of the genome and repetitive regions: rDNA and telomeric Y' regions. We further observed that circles can have flexible inheritance patterns: [HXT6/7circle] normally segregates to mother cells but in low glucose is present in up to 50% of cells, the majority of which must have inherited this circle from their mother. Interestingly, [HXT6/7circle] cells are eventually replaced by cells carrying stable chromosomal HXT6 HXT6/7 HXT7 amplifications, suggesting circular DNAs are intermediates in chromosomal amplifications. In conclusion, the heterogeneity of circular DNA offers flexibility in adaptation, but this heterogeneity is remarkably diminished with age.
Collapse
Affiliation(s)
- Iñigo Prada-Luengo
- Ecology and Evolution, Department of Biology, University of Copenhagen, Copenhagen DK-2100, Denmark
| | - Henrik D Møller
- Ecology and Evolution, Department of Biology, University of Copenhagen, Copenhagen DK-2100, Denmark
- Department of Biology, Institute of Biochemistry, ETH Zürich, Zurich CH-8093, Switzerland
| | - Rasmus A Henriksen
- Ecology and Evolution, Department of Biology, University of Copenhagen, Copenhagen DK-2100, Denmark
| | - Qian Gao
- Epigenetics Programme, The Babraham Institute, Babraham, Cambridge CB22 3-AT, UK
- Adaptimmune Ltd, Oxfordshire OX14 4RX, UK
| | - Camilla Eggert Larsen
- Ecology and Evolution, Department of Biology, University of Copenhagen, Copenhagen DK-2100, Denmark
| | - Sefa Alizadeh
- Ecology and Evolution, Department of Biology, University of Copenhagen, Copenhagen DK-2100, Denmark
| | - Lasse Maretty
- Department of Molecular Medicine, Aarhus University Hospital, Aarhus DK-8200, Denmark
| | - Jonathan Houseley
- Epigenetics Programme, The Babraham Institute, Babraham, Cambridge CB22 3-AT, UK
| | - Birgitte Regenberg
- Ecology and Evolution, Department of Biology, University of Copenhagen, Copenhagen DK-2100, Denmark
| |
Collapse
|
19
|
Møller HD, Ramos-Madrigal J, Prada-Luengo I, Gilbert MTP, Regenberg B. Near-Random Distribution of Chromosome-Derived Circular DNA in the Condensed Genome of Pigeons and the Larger, More Repeat-Rich Human Genome. Genome Biol Evol 2020; 12:3762-3777. [PMID: 31882998 PMCID: PMC6993614 DOI: 10.1093/gbe/evz281] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/20/2019] [Indexed: 12/15/2022] Open
Abstract
Extrachromosomal circular DNA (eccDNA) elements of chromosomal origin are known to be common in a number of eukaryotic species. However, it remains to be addressed whether genomic features such as genome size, the load of repetitive elements within a genome, and/or animal physiology affect the number of eccDNAs. Here, we investigate the distribution and numbers of eccDNAs in a condensed and less repeat-rich genome compared with the human genome, using Columba livia domestica (domestic rock pigeon) as a model organism. By sequencing eccDNA in blood and breast muscle from three pigeon breeds at various ages and with different flight behavior, we characterize 30,000 unique eccDNAs. We identify genomic regions that are likely hotspots for DNA circularization in breast muscle, including genes involved in muscle development. We find that although eccDNA counts do not correlate with the biological age in pigeons, the number of unique eccDNAs in a nonflying breed (king pigeons) is significantly higher (9-fold) than homing pigeons. Furthermore, a comparison between eccDNA from skeletal muscle in pigeons and humans reveals ∼9-10 times more unique eccDNAs per human nucleus. The fraction of eccDNA sequences, derived from repetitive elements, exist in proportions to genome content, that is, human 72.4% (expected 52.5%) and pigeon 8.7% (expected 5.5%). Overall, our results support that eccDNAs are common in pigeons, that the amount of unique eccDNA types per nucleus can differ between species as well as subspecies, and suggest that eccDNAs from repeats are found in proportions relative to the content of repetitive elements in a genome.
Collapse
Affiliation(s)
- Henrik Devitt Møller
- Department of Biology, University of Copenhagen, Denmark.,Department of Biology, Institute of Biochemistry, ETH Zürich, Switzerland
| | | | | | - M Thomas P Gilbert
- The GLOBE Institute, University of Copenhagen, Denmark.,NTNU University Museum, Trondheim, Norway
| | | |
Collapse
|
20
|
Kumar P, Kiran S, Saha S, Su Z, Paulsen T, Chatrath A, Shibata Y, Shibata E, Dutta A. ATAC-seq identifies thousands of extrachromosomal circular DNA in cancer and cell lines. SCIENCE ADVANCES 2020; 6:eaba2489. [PMID: 32440553 PMCID: PMC7228742 DOI: 10.1126/sciadv.aba2489] [Citation(s) in RCA: 84] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2019] [Accepted: 03/06/2020] [Indexed: 05/17/2023]
Abstract
Extrachromosomal circular DNAs (eccDNAs) are somatically mosaic and contribute to intercellular heterogeneity in normal and tumor cells. Because short eccDNAs are poorly chromatinized, we hypothesized that they are sequenced by tagmentation in ATAC-seq experiments without any enrichment of circular DNA. Indeed, ATAC-seq identified thousands of eccDNAs in cell lines that were validated by inverse PCR and by metaphase FISH. ATAC-seq in gliomas and glioblastomas identify hundreds of eccDNAs, including one containing the well-known EGFR gene amplicon from chr7. More than 18,000 eccDNAs, many carrying known cancer driver genes, are identified in a pan-cancer analysis of ATAC-seq libraries from 23 tumor types. Somatically mosaic eccDNAs are identified by ATAC-seq even before amplification is recognized by genome-wide copy number variation measurements. Thus, ATAC-seq is a sensitive method to detect eccDNA present in a tumor at the pre-amplification stage and can be used to predict resistance to therapy.
Collapse
Affiliation(s)
- Pankaj Kumar
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Shashi Kiran
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Shekhar Saha
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Zhangli Su
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Teressa Paulsen
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Ajay Chatrath
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Yoshiyuki Shibata
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Etsuko Shibata
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | | |
Collapse
|
21
|
Mehta D, Cornet L, Hirsch-Hoffmann M, Zaidi SSEA, Vanderschuren H. Full-length sequencing of circular DNA viruses and extrachromosomal circular DNA using CIDER-Seq. Nat Protoc 2020; 15:1673-1689. [PMID: 32246135 DOI: 10.1038/s41596-020-0301-0] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 01/20/2020] [Indexed: 12/19/2022]
Abstract
Circular DNA is ubiquitous in nature in the form of plasmids, circular DNA viruses, and extrachromosomal circular DNA (eccDNA) in eukaryotes. Sequencing of such molecules is essential to profiling virus distributions, discovering new viruses and understanding the roles of eccDNAs in eukaryotic cells. Circular DNA enrichment sequencing (CIDER-Seq) is a technique to enrich and accurately sequence circular DNA without the need for polymerase chain reaction amplification, cloning, and computational sequence assembly. The approach is based on randomly primed circular DNA amplification, which is followed by several enzymatic DNA repair steps and then by long-read sequencing. CIDER-Seq includes a custom data analysis package (CIDER-Seq Data Analysis Software 2) that implements the DeConcat algorithm to deconcatenate the long sequencing products of random circular DNA amplification into the intact sequences of the input circular DNA. The CIDER-Seq data analysis package can generate full-length annotated virus genomes, as well as circular DNA sequences of novel viruses. Applications of CIDER-Seq also include profiling of eccDNA molecules such as transposable elements (TEs) from biological samples. The method takes ~2 weeks to complete, depending on the computational resources available. Owing to the present constraints of long-read single-molecule sequencing, the accuracy of circular virus and eccDNA sequences generated by the CIDER-Seq method scales with sequence length, and the greatest accuracy is obtained for molecules <10 kb long.
Collapse
Affiliation(s)
- Devang Mehta
- Laboratory of Plant Genomics, Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada.
| | - Luc Cornet
- Plant Genetics, TERRA Teaching and Research Center, Gembloux Agro-Bio Tech, University of Liège, Gembloux, Belgium
| | | | - Syed Shan-E-Ali Zaidi
- Plant Genetics, TERRA Teaching and Research Center, Gembloux Agro-Bio Tech, University of Liège, Gembloux, Belgium
| | - Hervé Vanderschuren
- Plant Genetics, TERRA Teaching and Research Center, Gembloux Agro-Bio Tech, University of Liège, Gembloux, Belgium. .,Laboratory of Tropical Crop Improvement, Division of Crop Biotechnics, Biosystems Department, KU Leuven, Leuven, Belgium.
| |
Collapse
|
22
|
Ain Q, Schmeer C, Wengerodt D, Witte OW, Kretz A. Extrachromosomal Circular DNA: Current Knowledge and Implications for CNS Aging and Neurodegeneration. Int J Mol Sci 2020; 21:ijms21072477. [PMID: 32252492 PMCID: PMC7177960 DOI: 10.3390/ijms21072477] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 03/26/2020] [Accepted: 03/30/2020] [Indexed: 12/13/2022] Open
Abstract
Still unresolved is the question of how a lifetime accumulation of somatic gene copy number alterations impact organ functionality and aging and age-related pathologies. Such an issue appears particularly relevant in the broadly post-mitotic central nervous system (CNS), where non-replicative neurons are restricted in DNA-repair choices and are prone to accumulate DNA damage, as they remain unreplaced over a lifetime. Both DNA injuries and consecutive DNA-repair strategies are processes that can evoke extrachromosomal circular DNA species, apparently from either part of the genome. Due to their capacity to amplify gene copies and related transcripts, the individual cellular load of extrachromosomal circular DNAs will contribute to a dynamic pool of additional coding and regulatory chromatin elements. Analogous to tumor tissues, where the mosaicism of circular DNAs plays a well-characterized role in oncogene plasticity and drug resistance, we suggest involvement of the "circulome" also in the CNS. Accordingly, we summarize current knowledge on the molecular biogenesis, homeostasis and gene regulatory impacts of circular extrachromosomal DNA and propose, in light of recent discoveries, a critical role in CNS aging and neurodegeneration. Future studies will elucidate the influence of individual extrachromosomal DNA species according to their sequence complexity and regional distribution or cell-type-specific abundance.
Collapse
Affiliation(s)
- Quratul Ain
- Hans-Berger Department of Neurology, Jena University Hospital, 07747 Jena, Thuringia, Germany; (Q.A.); (C.S.); (D.W.); (O.W.W.)
| | - Christian Schmeer
- Hans-Berger Department of Neurology, Jena University Hospital, 07747 Jena, Thuringia, Germany; (Q.A.); (C.S.); (D.W.); (O.W.W.)
- Jena Center for Healthy Ageing, Jena University Hospital, 07747 Jena, Thuringia, Germany
| | - Diane Wengerodt
- Hans-Berger Department of Neurology, Jena University Hospital, 07747 Jena, Thuringia, Germany; (Q.A.); (C.S.); (D.W.); (O.W.W.)
| | - Otto W. Witte
- Hans-Berger Department of Neurology, Jena University Hospital, 07747 Jena, Thuringia, Germany; (Q.A.); (C.S.); (D.W.); (O.W.W.)
- Jena Center for Healthy Ageing, Jena University Hospital, 07747 Jena, Thuringia, Germany
| | - Alexandra Kretz
- Hans-Berger Department of Neurology, Jena University Hospital, 07747 Jena, Thuringia, Germany; (Q.A.); (C.S.); (D.W.); (O.W.W.)
- Jena Center for Healthy Ageing, Jena University Hospital, 07747 Jena, Thuringia, Germany
- Correspondence:
| |
Collapse
|
23
|
Circle-Seq: Isolation and Sequencing of Chromosome-Derived Circular DNA Elements in Cells. Methods Mol Biol 2020; 2119:165-181. [PMID: 31989524 DOI: 10.1007/978-1-0716-0323-9_15] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Chromosome-derived extrachromosomal circular DNA elements (eccDNAs) are detected in all eukaryotes examined so far. Here I describe the Circle-Seq protocol, applicable for physical enrichment of eccDNAs of a broad size range, combined with sequence confirmation of circular structures.Briefly, by concise alkaline treatment and gentle gravity flow-through an ion-exchange column, eccDNAs are enriched in the eluate fraction. EccDNAs are enzymatically isolated by extensive Plasmid-Safe DNase digestion of linear chromosomes and further enriched by φ29 rolling circle amplification. By means of high throughput sequencing of amplified eccDNA and custom eccDNA mapping software, around ten-thousand unique eccDNA types could be detected at nucleotide resolution in a million human muscle nuclei by this method.
Collapse
|
24
|
Hull RM, King M, Pizza G, Krueger F, Vergara X, Houseley J. Transcription-induced formation of extrachromosomal DNA during yeast ageing. PLoS Biol 2019; 17:e3000471. [PMID: 31794573 PMCID: PMC6890164 DOI: 10.1371/journal.pbio.3000471] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Accepted: 10/31/2019] [Indexed: 12/22/2022] Open
Abstract
Extrachromosomal circular DNA (eccDNA) facilitates adaptive evolution by allowing rapid and extensive gene copy number variation and is implicated in the pathology of cancer and ageing. Here, we demonstrate that yeast aged under environmental copper accumulate high levels of eccDNA containing the copper-resistance gene CUP1. Transcription of the tandemly repeated CUP1 gene causes CUP1 eccDNA accumulation, which occurs in the absence of phenotypic selection. We have developed a sensitive and quantitative eccDNA sequencing pipeline that reveals CUP1 eccDNA accumulation on copper exposure to be exquisitely site specific, with no other detectable changes across the eccDNA complement. eccDNA forms de novo from the CUP1 locus through processing of DNA double-strand breaks (DSBs) by Sae2, Mre11 and Mus81, and genome-wide analyses show that other protein coding eccDNA species in aged yeast share a similar biogenesis pathway. Although abundant, we find that CUP1 eccDNA does not replicate efficiently, and high-copy numbers in aged cells arise through frequent formation events combined with asymmetric DNA segregation. The transcriptional stimulation of CUP1 eccDNA formation shows that age-linked genetic change varies with transcription pattern, resulting in gene copy number profiles tailored by environment. Transcription can cause the de novo formation of protein-coding extrachromosomal DNA that accumulates in ageing yeast cells; these extrachromosomal circular DNA molecules form frequently by a DNA double strand break repair mechanism.
Collapse
Affiliation(s)
- Ryan M. Hull
- Epigenetics Programme, Babraham Institute, Cambridge, United Kingdom
| | - Michelle King
- Epigenetics Programme, Babraham Institute, Cambridge, United Kingdom
| | - Grazia Pizza
- Epigenetics Programme, Babraham Institute, Cambridge, United Kingdom
| | - Felix Krueger
- Babraham Bioinformatics, Babraham Institute, Cambridge, United Kingdom
| | - Xabier Vergara
- Epigenetics Programme, Babraham Institute, Cambridge, United Kingdom
| | - Jonathan Houseley
- Epigenetics Programme, Babraham Institute, Cambridge, United Kingdom
- * E-mail:
| |
Collapse
|
25
|
Yerlici VT, Lu MW, Hoge CR, Miller RV, Neme R, Khurana JS, Bracht JR, Landweber LF. Programmed genome rearrangements in Oxytricha produce transcriptionally active extrachromosomal circular DNA. Nucleic Acids Res 2019; 47:9741-9760. [PMID: 31504770 PMCID: PMC6765146 DOI: 10.1093/nar/gkz725] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 08/02/2019] [Accepted: 08/20/2019] [Indexed: 11/13/2022] Open
Abstract
Extrachromosomal circular DNA (eccDNA) is both a driver of eukaryotic genome instability and a product of programmed genome rearrangements, but its extent had not been surveyed in Oxytricha, a ciliate with elaborate DNA elimination and translocation during development. Here, we captured rearrangement-specific circular DNA molecules across the genome to gain insight into its processes of programmed genome rearrangement. We recovered thousands of circularly excised Tc1/mariner-type transposable elements and high confidence non-repetitive germline-limited loci. We verified their bona fide circular topology using circular DNA deep-sequencing, 2D gel electrophoresis and inverse polymerase chain reaction. In contrast to the precise circular excision of transposable elements, we report widespread heterogeneity in the circular excision of non-repetitive germline-limited loci. We also demonstrate that circular DNAs are transcribed in Oxytricha, producing rearrangement-specific long non-coding RNAs. The programmed formation of thousands of eccDNA molecules makes Oxytricha a model system for studying nucleic acid topology. It also suggests involvement of eccDNA in programmed genome rearrangement.
Collapse
Affiliation(s)
- V Talya Yerlici
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA.,Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Michael W Lu
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA.,Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Carla R Hoge
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Richard V Miller
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA.,Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Rafik Neme
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Jaspreet S Khurana
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - John R Bracht
- Department of Biology, American University, Washington, DC 20016, USA
| | - Laura F Landweber
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA.,Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| |
Collapse
|
26
|
Zhu J, Chen S, Zhang F, Wang L. Cell-Free eccDNAs: A New Type of Nucleic Acid Component for Liquid Biopsy? Mol Diagn Ther 2019; 22:515-522. [PMID: 29959693 DOI: 10.1007/s40291-018-0348-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Extrachromosomal circular DNAs (eccDNAs) are circular DNAs that are originated from chromosomes, but are independent from chromosomal DNA. The eccDNAs are commonly found in various tissues and cell types, and in both normal and diseased conditions. Due to their highly heterogeneous origins and being widely spread in nearly all eukaryotes, the eccDNAs are believed to reflect the genome's plasticity and instability. With the assistance of next-generation sequencing, more eccDNAs have been characterized at the molecular level. Recently, eccDNAs have been reported as cell-free DNAs in the circulation system. Importantly, these circulating eccDNAs have shown some evidence with disease associations, suggesting their potential utility as a new type of biomarker for disease detection, treatment assessment and progress surveillance. However, many challenges need to be addressed before implementing the eccDNAs as a new source of genetic material for liquid biopsy.
Collapse
Affiliation(s)
- Jing Zhu
- Laboratory of Medical Genetics, Harbin Medical University, 157 Baojian Road, Harbin, 150081, Heilongjiang, China.
| | - Siyu Chen
- Laboratory of Medical Genetics, Harbin Medical University, 157 Baojian Road, Harbin, 150081, Heilongjiang, China
| | - Fan Zhang
- School of Computer Science and Technology, Harbin Institute of Technology, Harbin, 150001, Heilongjiang, China
| | - Liang Wang
- Department of Pathology and MCW Cancer Center, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA.
| |
Collapse
|
27
|
Cho J, Benoit M, Catoni M, Drost HG, Brestovitsky A, Oosterbeek M, Paszkowski J. Sensitive detection of pre-integration intermediates of long terminal repeat retrotransposons in crop plants. NATURE PLANTS 2019; 5:26-33. [PMID: 30531940 PMCID: PMC6366555 DOI: 10.1038/s41477-018-0320-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2018] [Accepted: 11/07/2018] [Indexed: 05/02/2023]
Abstract
Retrotransposons have played an important role in the evolution of host genomes1,2. Their impact is mainly deduced from the composition of DNA sequences that have been fixed over evolutionary time2. Such studies provide important 'snapshots' reflecting the historical activities of transposons but do not predict current transposition potential. We previously reported sequence-independent retrotransposon trapping (SIRT) as a method that, by identification of extrachromosomal linear DNA (eclDNA), revealed the presence of active long terminal repeat (LTR) retrotransposons in Arabidopsis3. However, SIRT cannot be applied to large and transposon-rich genomes, as found in crop plants. We have developed an alternative approach named ALE-seq (amplification of LTR of eclDNAs followed by sequencing) for such situations. ALE-seq reveals sequences of 5' LTRs of eclDNAs after two-step amplification: in vitro transcription and subsequent reverse transcription. Using ALE-seq in rice, we detected eclDNAs for a novel Copia family LTR retrotransposon, Go-on, which is activated by heat stress. Sequencing of rice accessions revealed that Go-on has preferentially accumulated in Oryza sativa ssp. indica rice grown at higher temperatures. Furthermore, ALE-seq applied to tomato fruits identified a developmentally regulated Gypsy family of retrotransposons. A bioinformatic pipeline adapted for ALE-seq data analyses is used for the direct and reference-free annotation of new, active retroelements. This pipeline allows assessment of LTR retrotransposon activities in organisms for which genomic sequences and/or reference genomes are either unavailable or of low quality.
Collapse
Affiliation(s)
- Jungnam Cho
- The Sainsbury Laboratory, University of Cambridge, Cambridge, UK.
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai, China.
- CAS-JIC Centre of Excellence for Plant and Microbial Science, Chinese Academy of Sciences, Shanghai, China.
| | - Matthias Benoit
- The Sainsbury Laboratory, University of Cambridge, Cambridge, UK
| | - Marco Catoni
- The Sainsbury Laboratory, University of Cambridge, Cambridge, UK
- School of Biosciences, University of Birmingham, Birmingham, UK
| | - Hajk-Georg Drost
- The Sainsbury Laboratory, University of Cambridge, Cambridge, UK
| | | | - Matthijs Oosterbeek
- The Sainsbury Laboratory, University of Cambridge, Cambridge, UK
- Laboratory of Nematology, Wageningen University, Wageningen, the Netherlands
| | - Jerzy Paszkowski
- The Sainsbury Laboratory, University of Cambridge, Cambridge, UK.
- Radachowka 37, Kolbiel, Poland.
| |
Collapse
|
28
|
Abstract
The human genome is generally organized into stable chromosomes, and only tumor cells are known to accumulate kilobase (kb)-sized extrachromosomal circular DNA elements (eccDNAs). However, it must be expected that kb eccDNAs exist in normal cells as a result of mutations. Here, we purify and sequence eccDNAs from muscle and blood samples from 16 healthy men, detecting ~100,000 unique eccDNA types from 16 million nuclei. Half of these structures carry genes or gene fragments and the majority are smaller than 25 kb. Transcription from eccDNAs suggests that eccDNAs reside in nuclei and recurrence of certain eccDNAs in several individuals implies DNA circularization hotspots. Gene-rich chromosomes contribute to more eccDNAs per megabase and the most transcribed protein-coding gene in muscle, TTN (titin), provides the most eccDNAs per gene. Thus, somatic genomes are rich in chromosome-derived eccDNAs that may influence phenotypes through altered gene copy numbers and transcription of full-length or truncated genes. Somatic cells can accumulate structural variations such as deletions. Here, Møller et al. show that normal human cells generate large extrachromosomal circular DNAs (eccDNAs), most likely the products of excised DNA, that can be transcriptionally active and, thus, may have phenotypic consequences.
Collapse
|
29
|
Prasinovirus Attack of Ostreococcus Is Furtive by Day but Savage by Night. J Virol 2018; 92:JVI.01703-17. [PMID: 29187539 PMCID: PMC5790953 DOI: 10.1128/jvi.01703-17] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 11/09/2017] [Indexed: 12/12/2022] Open
Abstract
Prasinoviruses are large DNA viruses that infect diverse genera of green microalgae worldwide in aquatic ecosystems, but molecular knowledge of their life cycles is lacking. Several complete genomes of both these viruses and their marine algal hosts are now available and have been used to show the pervasive presence of these species in microbial metagenomes. We have analyzed the life cycle of Ostreococcus tauri virus 5 (OtV5), a lytic virus, using transcriptome sequencing (RNA-Seq) from 12 time points of healthy or infected Ostreococcus tauri cells over a day/night cycle in culture. In the day, viral gene transcription remained low while host nitrogen metabolism gene transcription was initially strongly repressed for two successive time points before being induced for 8 h, but during the night, viral transcription increased steeply while host nitrogen metabolism genes were repressed and many host functions that are normally reduced in the dark appeared to be compensated either by genes expressed from the virus or by increased expression of a subset of 4.4% of the host's genes. Some host cells underwent lysis progressively during the night, but a larger proportion were lysed the following morning. Our data suggest that the life cycles of algal viruses mirror the diurnal rhythms of their hosts.IMPORTANCE Prasinoviruses are common in marine environments, and although several complete genomes of these viruses and their hosts have been characterized, little is known about their life cycles. Here we analyze in detail the transcriptional changes occurring over a 27-h-long experiment in a natural diurnal rhythm, in which the growth of host cells is to some extent synchronized, so that host DNA replication occurs late in the day or early in the night and cell division occurs during the night. Surprisingly, viral transcription remains quiescent over the daytime, when the most energy (from light) is available, but during the night viral transcription activates, accompanied by expression of a few host genes that are probably required by the virus. Although our experiment was accomplished in the lab, cyclical changes have been documented in host transcription in the ocean. Our observations may thus be relevant for eukaryotic phytoplankton in natural environments.
Collapse
|
30
|
Zhu J, Zhang F, Du M, Zhang P, Fu S, Wang L. Molecular characterization of cell-free eccDNAs in human plasma. Sci Rep 2017; 7:10968. [PMID: 28887493 PMCID: PMC5591271 DOI: 10.1038/s41598-017-11368-w] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 08/23/2017] [Indexed: 12/18/2022] Open
Abstract
Extrachromosomal circular DNAs (eccDNAs) have been reported in most eukaryotes. However, little is known about the cell-free eccDNA profiles in circulating system such as blood. To characterize plasma cell-free eccDNAs, we performed sequencing analysis in 26 libraries from three blood donors and negative controls. We identified thousands of unique plasma eccDNAs in the three subjects. We observed proportional eccDNA increase with initial DNA input. The detected eccDNAs were also associated with circular DNA enrichment efficiency. Increasing the sequencing depth in an additional sample identified many more eccDNAs with highly heterogenous molecular structure. Size distribution of eccDNAs varied significantly from 31 bp to 19,989 bp. We found significantly higher GC content in smaller eccDNAs (<500 bp) than the larger ones (>500 bp) (p < 0.01). We also found an enrichment of eccDNAs at exons and 3′UTR (enrichment folds from 1.36 to 3.1) as well as the DNase hypersensitive sites (1.58–2.42 fold), H3K4Me1 (1.23–1.42 fold) and H3K27Ac (1.33–1.62 fold) marks. Junction sequence analysis suggested fundamental role of nonhomologous end joining mechanism during eccDNA formation. Further characterization of the extracellular eccDNAs in peripheral blood will facilitate understanding of their molecular mechanisms and potential clinical utilities.
Collapse
Affiliation(s)
- Jing Zhu
- Laboratory of Medical Genetics, Harbin Medical University, Harbin, Heilongjiang, 150081, China.,Department of Pathology and MCW Cancer Center, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
| | - Fan Zhang
- School of Computer Science and Technology, Harbin Institute of Technology, Harbin, Heilongjiang, 150001, China
| | - Meijun Du
- Department of Pathology and MCW Cancer Center, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
| | - Peng Zhang
- Department of Pathology and MCW Cancer Center, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
| | - Songbin Fu
- Laboratory of Medical Genetics, Harbin Medical University, Harbin, Heilongjiang, 150081, China
| | - Liang Wang
- Department of Pathology and MCW Cancer Center, Medical College of Wisconsin, Milwaukee, WI, 53226, USA.
| |
Collapse
|
31
|
Sequencing the extrachromosomal circular mobilome reveals retrotransposon activity in plants. PLoS Genet 2017; 13:e1006630. [PMID: 28212378 PMCID: PMC5338827 DOI: 10.1371/journal.pgen.1006630] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Revised: 03/06/2017] [Accepted: 02/10/2017] [Indexed: 11/19/2022] Open
Abstract
Retrotransposons are mobile genetic elements abundant in plant and animal genomes. While efficiently silenced by the epigenetic machinery, they can be reactivated upon stress or during development. Their level of transcription not reflecting their transposition ability, it is thus difficult to evaluate their contribution to the active mobilome. Here we applied a simple methodology based on the high throughput sequencing of extrachromosomal circular DNA (eccDNA) forms of active retrotransposons to characterize the repertoire of mobile retrotransposons in plants. This method successfully identified known active retrotransposons in both Arabidopsis and rice material where the epigenome is destabilized. When applying mobilome-seq to developmental stages in wild type rice, we identified PopRice as a highly active retrotransposon producing eccDNA forms in the wild type endosperm. The mobilome-seq strategy opens new routes for the characterization of a yet unexplored fraction of plant genomes.
Collapse
|
32
|
Mourier T. Transposable elements and circular DNAs. Mob Genet Elements 2016; 6:e1240748. [PMID: 28090380 PMCID: PMC5173269 DOI: 10.1080/2159256x.2016.1240748] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Accepted: 09/20/2016] [Indexed: 01/06/2023] Open
Abstract
Circular DNAs are extra-chromosomal fragments that become circularized by genomic recombination events. We have recently shown that yeast LTR elements generate circular DNAs through recombination events between their flanking long terminal repeats (LTRs). Similarly, circular DNAs can be generated by recombination between LTRs residing at different genomic loci, in which case the circular DNA will contain the intervening sequence. In yeast, this can result in gene copy number variations when circles contain genes and origins of replication. Here, I speculate on the potential and implications of circular DNAs generated through recombination between human transposable elements.
Collapse
Affiliation(s)
- Tobias Mourier
- Pathogen Genomics Laboratory, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology , Thuwal, Saudi Arabia
| |
Collapse
|
33
|
Mourier T. Potential movement of transposable elements through DNA circularization. Curr Genet 2016; 62:697-700. [PMID: 26979517 DOI: 10.1007/s00294-016-0592-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 03/05/2016] [Accepted: 03/07/2016] [Indexed: 01/09/2023]
Abstract
The generation of circular DNAs is a relatively unrecognized type of genomic structural variation, but recent findings point to a possible role of circular DNAs in the movement of transposable elements. Circularization of genomic DNA is observed across eukaryotic species, in a range of different cell types, and from all parts of the genome. A recent study on circular DNAs in yeast found that transposable element sequence residing in circular structures mostly corresponded to full-length transposable elements. Transposable elements are mobile genetic elements scattered across eukaryotic genomes. Different classes of transposable elements move either through a copy-and-paste or a cut-and-paste. As circular DNA structures may recombine with the genome and re-integrate into a novel genomic locus, transposable elements could move through circularization. In yeast, the predominant type of transposable element is a so-called LTR (long terminal repeats) retrotransposable element that moves through a copy-and-paste mechanism. The observed circularization of this element means it potentially could move through a cut-and-paste mechanism as well. Although further experimental evidence is needed to establish the extent to which movement of transposable elements through DNA circularization takes place, such movement is likely to have a functional impact on the genomic context.
Collapse
Affiliation(s)
- Tobias Mourier
- Centre for GeoGenetics, Natural History Museum of Denmark, University of Copenhagen, Oester Voldgade 5-7, 1350, Copenhagen K, Denmark.
| |
Collapse
|