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Kohlrausch FB, Wang F, McKerrow W, Grivainis M, Fenyo D, Keefe DL. Mapping of long interspersed element-1 (L1) insertions by TIPseq provides information about sub chromosomal genetic variation in human embryos. J Assist Reprod Genet 2024:10.1007/s10815-024-03176-9. [PMID: 38951360 DOI: 10.1007/s10815-024-03176-9] [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: 07/14/2023] [Accepted: 06/12/2024] [Indexed: 07/03/2024] Open
Abstract
PURPOSE Retrotransposons play important roles during early development when they are transiently de-repressed during epigenetic reprogramming. Long interspersed element-1 (L1), the only autonomous retrotransposon in humans, comprises 17% of the human genome. We applied the Single Cell Transposon Insertion Profiling by Sequencing (scTIPseq) to characterize and map L1 insertions in human embryos. METHODS Sixteen cryopreserved, genetically tested, human blastocysts, were accessed from consenting couples undergoing IVF at NYU Langone Fertility Center. Additionally, four trios (father, mother, and embryos) were also evaluated. scTIPseq was applied to map L1 insertions in all samples, using L1 locations reported in the 1000 Genomes as controls. RESULTS Twenty-nine unknown and unique insertions were observed in the sixteen embryos. Most were intergenic; no insertions were located in exons or immediately upstream of genes. The location or number of unknown insertions did not differ between euploid and aneuploid embryos, suggesting they are not merely markers of aneuploidy. Rather, scTIPseq provides novel information about sub-chromosomal structural variation in human embryos. Trio analyses showed a parental origin of all L1 insertions in embryos. CONCLUSION Several studies have measured L1 expression at different stages of development in mice, but this study for the first time reports unknown insertions in human embryos that were inherited from one parent, confirming no de novo L1 insertions occurred in parental germline or during embryogenesis. Since one-third of euploid embryo transfers fail, future studies would be useful for understanding whether these sub-chromosomal genetic variants or de novo L1 insertions affect embryo developmental potential.
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Affiliation(s)
- Fabiana B Kohlrausch
- Departamento de Biologia Geral, Instituto de Biologia, Universidade Federal Fluminense, Niterói, RJ, 24210-201, Brazil.
- Department of Obstetrics and Gynecology, New York University, New York, NY, 10016, USA.
| | - Fang Wang
- Department of Obstetrics and Gynecology, New York University, New York, NY, 10016, USA
| | - Wilson McKerrow
- Institute for Systems Genetics, New York University, New York, NY, 10016, USA
| | - Mark Grivainis
- Institute for Systems Genetics, New York University, New York, NY, 10016, USA
| | - David Fenyo
- Institute for Systems Genetics, New York University, New York, NY, 10016, USA
| | - David L Keefe
- Department of Obstetrics and Gynecology, New York University, New York, NY, 10016, USA
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2
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Wu Y, Wang J, Zhao J, Su Y, Li X, Chen Z, Wu X, Huang S, He X, Liang L. LTR retrotransposon-derived LncRNA LINC01446 promotes hepatocellular carcinoma progression and angiogenesis by regulating the SRPK2/SRSF1/VEGF axis. Cancer Lett 2024; 598:217088. [PMID: 38945203 DOI: 10.1016/j.canlet.2024.217088] [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: 01/08/2024] [Revised: 06/15/2024] [Accepted: 06/25/2024] [Indexed: 07/02/2024]
Abstract
The causal link between long terminal repeat (LTR) retrotransposon-derived lncRNAs and hepatocellular carcinoma (HCC) remains elusive and whether these cancer-exclusive lncRNAs contribute to the effectiveness of current HCC therapies is yet to explore. Here, we investigated the activation of LTR retrotransposon-derived lncRNAs in a broad range of liver diseases. We found that LTR retrotransposon-derived lncRNAs are mainly activated in HCC and is correlated with the proliferation status of HCC. Furthermore, we discovered that an LTR retrotransposon-derived lncRNA, LINC01446, exhibits specific expression in HCC. HCC patients with higher LINC01446 expression had shorter overall survival times. In vitro and in vivo assays showed that LINC01446 promoted HCC growth and angiogenesis. Mechanistically, LINC01446 bound to serine/arginine protein kinase 2 (SRPK2) and activated its downstream target, serine/arginine splicing factor 1 (SRSF1). Furthermore, activation of the SRPK2-SRSF1 axis increased the splicing and expression of VEGF isoform A165 (VEGFA165). Notably, inhibiting LINC01446 expression dramatically impaired tumor growth in vivo and resulted in better therapeutic outcomes when combined with antiangiogenic agents. In addition, we found that the transcription factor MESI2 bound to the cryptic MLT2B3 LTR promoter and drove LINC01446 transcription in HCC cells. Taken together, our findings demonstrate that LTR retrotransposon-derived LINC01446 promotes the progression of HCC by activating the SRPK2/SRSF1/VEGFA165 axis and highlight targeting LINC01446 as a potential therapeutic strategy for HCC patients.
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Affiliation(s)
- Yangjun Wu
- Fudan University Shanghai Cancer Center and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China; Department of Gynecologic Oncology, Fudan University Shanghai Cancer Center, Fudan University, Shanghai, China; Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Jiajia Wang
- Fudan University Shanghai Cancer Center and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
| | - Jingjing Zhao
- Fudan University Shanghai Cancer Center and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
| | - Yue Su
- Fudan University Shanghai Cancer Center and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
| | - Xinrong Li
- Fudan University Shanghai Cancer Center and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
| | - Zhiao Chen
- Fudan University Shanghai Cancer Center and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
| | - Xiaohua Wu
- Department of Gynecologic Oncology, Fudan University Shanghai Cancer Center, Fudan University, Shanghai, China; Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Shenglin Huang
- Fudan University Shanghai Cancer Center and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China; Department of Integrative Oncology, Fudan University Shanghai Cancer Center, China
| | - Xianghuo He
- Fudan University Shanghai Cancer Center and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China.
| | - Linhui Liang
- Fudan University Shanghai Cancer Center and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China.
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3
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Zhang X, Celic I, Mitchell H, Stuckert S, Vedula L, Han J. Comprehensive profiling of L1 retrotransposons in mouse. Nucleic Acids Res 2024; 52:5166-5178. [PMID: 38647072 PMCID: PMC11109951 DOI: 10.1093/nar/gkae273] [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: 11/13/2023] [Revised: 03/25/2024] [Accepted: 04/06/2024] [Indexed: 04/25/2024] Open
Abstract
L1 elements are retrotransposons currently active in mammals. Although L1s are typically silenced in most normal tissues, elevated L1 expression is associated with a variety of conditions, including cancer, aging, infertility and neurological disease. These associations have raised interest in the mapping of human endogenous de novo L1 insertions, and a variety of methods have been developed for this purpose. Adapting these methods to mouse genomes would allow us to monitor endogenous in vivo L1 activity in controlled, experimental conditions using mouse disease models. Here, we use a modified version of transposon insertion profiling, called nanoTIPseq, to selectively enrich young mouse L1s. By linking this amplification step with nanopore sequencing, we identified >95% annotated L1s from C57BL/6 genomic DNA using only 200 000 sequencing reads. In the process, we discovered 82 unannotated L1 insertions from a single C57BL/6 genome. Most of these unannotated L1s were near repetitive sequence and were not found with short-read TIPseq. We used nanoTIPseq on individual mouse breast cancer cells and were able to identify the annotated and unannotated L1s, as well as new insertions specific to individual cells, providing proof of principle for using nanoTIPseq to interrogate retrotransposition activity at the single-cell level in vivo.
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Affiliation(s)
- Xuanming Zhang
- Department of Biochemistry and Molecular Biology, Tulane University School of Medicine, New Orleans, LA 70112, USA
- Tulane Cancer Center, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - Ivana Celic
- Department of Biochemistry and Molecular Biology, Tulane University School of Medicine, New Orleans, LA 70112, USA
- Tulane Cancer Center, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - Hannah Mitchell
- Department of Biochemistry and Molecular Biology, Tulane University School of Medicine, New Orleans, LA 70112, USA
- Tulane Cancer Center, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - Sam Stuckert
- Department of Biochemistry and Molecular Biology, Tulane University School of Medicine, New Orleans, LA 70112, USA
- Tulane Cancer Center, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - Lalitha Vedula
- Department of Biochemistry and Molecular Biology, Tulane University School of Medicine, New Orleans, LA 70112, USA
- Tulane Cancer Center, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - Jeffrey S Han
- Department of Biochemistry and Molecular Biology, Tulane University School of Medicine, New Orleans, LA 70112, USA
- Tulane Cancer Center, Tulane University School of Medicine, New Orleans, LA 70112, USA
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4
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Lee M, Ahmad SF, Xu J. Regulation and function of transposable elements in cancer genomes. Cell Mol Life Sci 2024; 81:157. [PMID: 38556602 PMCID: PMC10982106 DOI: 10.1007/s00018-024-05195-2] [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: 12/03/2023] [Revised: 02/28/2024] [Accepted: 03/01/2024] [Indexed: 04/02/2024]
Abstract
Over half of human genomic DNA is composed of repetitive sequences generated throughout evolution by prolific mobile genetic parasites called transposable elements (TEs). Long disregarded as "junk" or "selfish" DNA, TEs are increasingly recognized as formative elements in genome evolution, wired intimately into the structure and function of the human genome. Advances in sequencing technologies and computational methods have ushered in an era of unprecedented insight into how TE activity impacts human biology in health and disease. Here we discuss the current views on how TEs have shaped the regulatory landscape of the human genome, how TE activity is implicated in human cancers, and how recent findings motivate novel strategies to leverage TE activity for improved cancer therapy. Given the crucial role of methodological advances in TE biology, we pair our conceptual discussions with an in-depth review of the inherent technical challenges in studying repeats, specifically related to structural variation, expression analyses, and chromatin regulation. Lastly, we provide a catalog of existing and emerging assays and bioinformatic software that altogether are enabling the most sophisticated and comprehensive investigations yet into the regulation and function of interspersed repeats in cancer genomes.
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Affiliation(s)
- Michael Lee
- Department of Pediatrics, Children's Medical Center Research Institute, University of Texas Southwestern Medical Center, 6000 Harry Hines Blvd., Dallas, TX, 75390, USA.
| | - Syed Farhan Ahmad
- Department of Pathology, Center of Excellence for Leukemia Studies, St. Jude Children's Research Hospital, 262 Danny Thomas Place - MS 345, Memphis, TN, 38105, USA
| | - Jian Xu
- Department of Pathology, Center of Excellence for Leukemia Studies, St. Jude Children's Research Hospital, 262 Danny Thomas Place - MS 345, Memphis, TN, 38105, USA.
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5
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Zhang X, Celic I, Mitchell H, Stuckert S, Vedula L, Han JS. Comprehensive profiling of L1 retrotransposons in mouse. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.13.566638. [PMID: 38014156 PMCID: PMC10680791 DOI: 10.1101/2023.11.13.566638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
L1 elements are retrotransposons currently active in mammals. Although L1s are typically silenced in most normal tissues, elevated L1 expression is associated with a variety of conditions, including cancer, aging, infertility, and neurological disease. These associations have raised interest in the mapping of human endogenous de novo L1 insertions, and a variety of methods have been developed for this purpose. Adapting these methods to mouse genomes would allow us to monitor endogenous in vivo L1 activity in controlled, experimental conditions using mouse disease models. Here we use a modified version of transposon insertion profiling, called nanoTIPseq, to selectively enrich young mouse L1s. By linking this amplification step with nanopore sequencing, we identified >95% annotated L1s from C57BL/6 genomic DNA using only 200,000 sequencing reads. In the process, we discovered 82 unannotated L1 insertions from a single C57BL/6 genome. Most of these unannotated L1s were near repetitive sequence and were not found with short-read TIPseq. We used nanoTIPseq on individual mouse breast cancer cells and were able to identify the annotated and unannotated L1s, as well as new insertions specific to individual cells, providing proof of principle for using nanoTIPseq to interrogate retrotransposition activity at the single cell level in vivo .
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6
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Berteli TS, Wang F, McKerrow W, Navarro PA, Fenyo D, Boeke JD, Kohlrausch FB, Keefe DL. Transposon insertion profiling by sequencing (TIPseq) identifies novel LINE-1 insertions in human sperm. J Assist Reprod Genet 2023; 40:1835-1843. [PMID: 37310664 PMCID: PMC10371950 DOI: 10.1007/s10815-023-02852-6] [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: 03/27/2023] [Accepted: 06/01/2023] [Indexed: 06/14/2023] Open
Abstract
PURPOSE Long interspersed nuclear element-1 (LINE-1 or L1) comprises 17% of the human genome. Retrotransposons may perturb gene integrity or alter gene expression by altering regulatory regions in the genome. The germline employs a number of mechanisms, including cytosine methylation, to repress retrotransposon transcription throughout most of life. Demethylation during germ cell and early embryo development de-represses retrotransposons. Intriguingly, de novo genetic variation appearing in sperm has been implicated in a number of disorders in offspring, including autism spectrum disorder, schizophrenia, and bipolar disorder. We hypothesize that human sperm exhibit de novo retrotransposition and employ a new sequencing method, single cell transposon insertion profiling by sequencing (scTIPseq) to map them in small amounts of human sperm. METHODS Cross-sectional case-control study of sperm samples (n=10 men; ages 32-55 years old) from consenting men undergoing IVF at NYU Langone Fertility Center. scTIPseq identified novel LINE-1 insertions in individual sperm and TIPseqHunter, a custom bioinformatics pipeline, compared the architecture of sperm LINE-1 to known LINE-1 insertions from the European database of Human specific LINE-1 (L1Hs) retrotransposon insertions (euL1db). RESULTS scTIPseq identified 17 novel insertions in sperm. New insertions were mainly intergenic or intronic. Only one sample did not exhibit new insertions. The location or number of novel insertions did not differ by paternal age. CONCLUSION This study for the first time reports novel LINE-1 insertions in human sperm, demonstrating the feasibility of scTIPseq, and identifies new contributors to genetic diversity in the human germ line.
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Affiliation(s)
- Thalita S Berteli
- Department of Obstetrics and Gynecology, NYU Grossman School of Medicine, New York, NY, USA.
- Human Reproduction Division, Department of Gynecology and Obstetrics, Faculty of Medicine of Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, SP, Brazil.
| | - Fang Wang
- Department of Obstetrics and Gynecology, NYU Grossman School of Medicine, New York, NY, USA
| | - Wilson McKerrow
- Institute for Systems Genetics, NYU Grossman School of Medicine, New York, NY, USA
| | - Paula A Navarro
- Human Reproduction Division, Department of Gynecology and Obstetrics, Faculty of Medicine of Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, SP, Brazil
| | - David Fenyo
- Institute for Systems Genetics, NYU Grossman School of Medicine, New York, NY, USA
| | - Jef D Boeke
- Institute for Systems Genetics, NYU Grossman School of Medicine, New York, NY, USA
| | - Fabiana B Kohlrausch
- Department of Obstetrics and Gynecology, NYU Grossman School of Medicine, New York, NY, USA
- Biology Institute, Department of General Biology, Fluminense Federal University (UFF), Niteroi, RJ, Brazil
| | - David L Keefe
- Department of Obstetrics and Gynecology, NYU Grossman School of Medicine, New York, NY, USA
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7
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Li TD, Murano K, Kitano T, Guo Y, Negishi L, Siomi H. TDP-43 safeguards the embryo genome from L1 retrotransposition. SCIENCE ADVANCES 2022; 8:eabq3806. [PMID: 36417507 PMCID: PMC9683724 DOI: 10.1126/sciadv.abq3806] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Accepted: 10/06/2022] [Indexed: 06/16/2023]
Abstract
Transposable elements (TEs) are genomic parasites that propagate within the host genome and introduce mutations. Long interspersed nuclear element-1 (LINE-1 or L1) is the major TE class, which occupies nearly 20% of the mouse genome. L1 is highly active in mammalian preimplantation embryos, posing a major threat to genome integrity, but the mechanism of stage-specific protection against L1 retrotransposition is unknown. Here, we show that TAR DNA-binding protein 43 (TDP-43), mutations in which constitute a major risk factor for amyotrophic lateral sclerosis, inhibits L1 retrotransposition in mouse embryonic stem cells (mESCs) and preimplantation embryos. Knockdown of TDP-43 resulted in massive genomic L1 expansion and impaired cell growth in preimplantation embryos and ESCs. Functional analysis demonstrated that TDP-43 interacts with L1 open reading frame 1 protein (L1 ORF1p) to mediate genomic protection, and loss of this interaction led to derepression of L1 retrotransposition. Our results identify TDP-43 as a guardian of the embryonic genome.
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Affiliation(s)
- Ten D. Li
- Department of Molecular Biology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Kensaku Murano
- Department of Molecular Biology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Tomohiro Kitano
- Department of Molecular Biology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Youjia Guo
- Department of Molecular Biology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Lumi Negishi
- Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, Tokyo 113-0032, Japan
| | - Haruhiko Siomi
- Department of Molecular Biology, Keio University School of Medicine, Tokyo 160-8582, Japan
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8
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Vourlaki IT, Castanera R, Ramos-Onsins SE, Casacuberta JM, Pérez-Enciso M. Transposable element polymorphisms improve prediction of complex agronomic traits in rice. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2022; 135:3211-3222. [PMID: 35931838 PMCID: PMC9482605 DOI: 10.1007/s00122-022-04180-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 07/12/2022] [Indexed: 06/15/2023]
Abstract
Transposon insertion polymorphisms can improve prediction of complex agronomic traits in rice compared to using SNPs only, especially when accessions to be predicted are less related to the training set. Transposon insertion polymorphisms (TIPs) are significant sources of genetic variation. Previous work has shown that TIPs can improve detection of causative loci on agronomic traits in rice. Here, we quantify the fraction of variance explained by single nucleotide polymorphisms (SNPs) compared to TIPs, and we explore whether TIPs can improve prediction of traits when compared to using only SNPs. We used eleven traits of agronomic relevance from by five different rice population groups (Aus, Indica, Aromatic, Japonica, and Admixed), 738 accessions in total. We assess prediction by applying data split validation in two scenarios. In the within-population scenario, we predicted performance of improved Indica varieties using the rest of Indica accessions. In the across population scenario, we predicted all Aromatic and Admixed accessions using the rest of populations. In each scenario, Bayes C and a Bayesian reproducible kernel Hilbert space regression were compared. We find that TIPs can explain an important fraction of total genetic variance and that they also improve genomic prediction. In the across population prediction scenario, TIPs outperformed SNPs in nine out of the eleven traits analyzed. In some traits like leaf senescence or grain width, using TIPs increased predictive correlation by 30-50%. Our results evidence, for the first time, that TIPs genotyping can improve prediction on complex agronomic traits in rice, especially when accessions to be predicted are less related to training accessions.
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Affiliation(s)
- Ioanna-Theoni Vourlaki
- Universitat Autònoma de Barcelona, Department of Animal Production, 08193, Bellaterra, Barcelona, Spain.
- Centre for Research in Agricultural Genomics CSIC-IRTA-UAB-UB, 08193, Bellaterra, Barcelona, Spain.
| | - Raúl Castanera
- Centre for Research in Agricultural Genomics CSIC-IRTA-UAB-UB, 08193, Bellaterra, Barcelona, Spain
| | - Sebastián E Ramos-Onsins
- Centre for Research in Agricultural Genomics CSIC-IRTA-UAB-UB, 08193, Bellaterra, Barcelona, Spain
| | - Josep M Casacuberta
- Centre for Research in Agricultural Genomics CSIC-IRTA-UAB-UB, 08193, Bellaterra, Barcelona, Spain
| | - Miguel Pérez-Enciso
- Universitat Autònoma de Barcelona, Department of Animal Production, 08193, Bellaterra, Barcelona, Spain.
- Centre for Research in Agricultural Genomics CSIC-IRTA-UAB-UB, 08193, Bellaterra, Barcelona, Spain.
- Catalan Institute for Research and Advanced studies, ICREA, 08010, Barcelona, Spain.
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9
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Somatic Mobilization: High Somatic Insertion Rate of mariner Transposable Element in Drosophila simulans. INSECTS 2022; 13:insects13050454. [PMID: 35621789 PMCID: PMC9144738 DOI: 10.3390/insects13050454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Revised: 05/09/2022] [Accepted: 05/10/2022] [Indexed: 11/17/2022]
Abstract
Although transposable elements (TEs) are usually silent in somatic tissues, they are sometimes mobilized in the soma and can potentially have biological consequences. The mariner element is one of the TEs involved in somatic mobilization (SM) in Drosophila and has a high rate of somatic excision. It is also known that temperature is an important factor in the increase of the mariner element SM in the fly. However, it is important to emphasize that excision is only one step of TE transposition, and the final step in this process is insertion. In the present study, we used an assay based on sequencing of the mariner flanking region and developed a pipeline to identify novel mariner insertions in Drosophila simulans at 20 and 28 °C. We found that flies carrying two mariner copies (one autonomous and one non-autonomous) had an average of 236.4 (±99.3) to 279 (±107.7) new somatic insertions at 20 °C and an average of 172.7 (±95.3) to 252.6 (±67.3) at 28 °C. In addition, we detected fragments containing mariner and others without mariner in the same regions with low-coverage long-read sequencing, indicating the process of excision and insertion. In conclusion, a low number of autonomous copies of the mariner transposon can promote a high rate of new somatic insertions during the developmental stages of Drosophila. Additionally, the developed method seems to be sensitive and adequate for the verification and estimation of somatic insertion.
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10
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Autio MI, Bin Amin T, Perrin A, Wong JY, Foo RSY, Prabhakar S. Transposable elements that have recently been mobile in the human genome. BMC Genomics 2021; 22:789. [PMID: 34732136 PMCID: PMC8567694 DOI: 10.1186/s12864-021-08085-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 10/14/2021] [Indexed: 11/29/2022] Open
Abstract
Background Transposable elements (TE) comprise nearly half of the human genome and their insertions have profound effects to human genetic diversification and as well as disease. Despite their abovementioned significance, there is no consensus on the TE subfamilies that remain active in the human genome. In this study, we therefore developed a novel statistical test for recently mobile subfamilies (RMSs), based on patterns of overlap with > 100,000 polymorphic indels. Results Our analysis produced a catalogue of 20 high-confidence RMSs, which excludes many false positives in public databases. Intriguingly though, it includes HERV-K, an LTR subfamily previously thought to be extinct. The RMS catalogue is strongly enriched for contributions to germline genetic disorders (P = 1.1e-10), and thus constitutes a valuable resource for diagnosing disorders of unknown aetiology using targeted TE-insertion screens. Remarkably, RMSs are also highly enriched for somatic insertions in diverse cancers (P = 2.8e-17), thus indicating strong correlations between germline and somatic TE mobility. Using CRISPR/Cas9 deletion, we show that an RMS-derived polymorphic TE insertion increased the expression of RPL17, a gene associated with lower survival in liver cancer. More broadly, polymorphic TE insertions from RMSs were enriched near genes with allele-specific expression, suggesting widespread effects on gene regulation. Conclusions By using a novel statistical test we have defined a catalogue of 20 recently mobile transposable element subfamilies. We illustrate the gene regulatory potential of RMS-derived polymorphic TE insertions, using CRISPR/Cas9 deletion in vitro on a specific candidate, as well as by genome wide analysis of allele-specific expression. Our study presents novel insights into TE mobility and regulatory potential and provides a key resource for human disease genetics and population history studies. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-021-08085-0.
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Affiliation(s)
- Matias I Autio
- Laboratory of Epigenomics and Chromatin Organization, Genome Institute of Singapore, A*STAR, Singapore, 138672, Singapore.,Cardiovascular Research Institute, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117599, Singapore
| | - Talal Bin Amin
- Spatial and Single Cell Systems, Genome Institute of Singapore, A*STAR, 60 Biopolis St, Genome #02-01, Singapore, 138672, Singapore
| | - Arnaud Perrin
- Laboratory of Epigenomics and Chromatin Organization, Genome Institute of Singapore, A*STAR, Singapore, 138672, Singapore.,Cardiovascular Research Institute, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117599, Singapore
| | - Jen Yi Wong
- Spatial and Single Cell Systems, Genome Institute of Singapore, A*STAR, 60 Biopolis St, Genome #02-01, Singapore, 138672, Singapore
| | - Roger S-Y Foo
- Laboratory of Epigenomics and Chromatin Organization, Genome Institute of Singapore, A*STAR, Singapore, 138672, Singapore.,Cardiovascular Research Institute, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117599, Singapore
| | - Shyam Prabhakar
- Spatial and Single Cell Systems, Genome Institute of Singapore, A*STAR, 60 Biopolis St, Genome #02-01, Singapore, 138672, Singapore.
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11
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Wang Y, Zhao B, Choi J, Lee EA. Genomic approaches to trace the history of human brain evolution with an emerging opportunity for transposon profiling of ancient humans. Mob DNA 2021; 12:22. [PMID: 34663455 PMCID: PMC8525043 DOI: 10.1186/s13100-021-00250-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Accepted: 09/27/2021] [Indexed: 12/17/2022] Open
Abstract
Transposable elements (TEs) significantly contribute to shaping the diversity of the human genome, and lines of evidence suggest TEs as one of driving forces of human brain evolution. Existing computational approaches, including cross-species comparative genomics and population genetic modeling, can be adapted for the study of the role of TEs in evolution. In particular, diverse ancient and archaic human genome sequences are increasingly available, allowing reconstruction of past human migration events and holding the promise of identifying and tracking TEs among other evolutionarily important genetic variants at an unprecedented spatiotemporal resolution. However, highly degraded short DNA templates and other unique challenges presented by ancient human DNA call for major changes in current experimental and computational procedures to enable the identification of evolutionarily important TEs. Ancient human genomes are valuable resources for investigating TEs in the evolutionary context, and efforts to explore ancient human genomes will potentially provide a novel perspective on the genetic mechanism of human brain evolution and inspire a variety of technological and methodological advances. In this review, we summarize computational and experimental approaches that can be adapted to identify and validate evolutionarily important TEs, especially for human brain evolution. We also highlight strategies that leverage ancient genomic data and discuss unique challenges in ancient transposon genomics.
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Affiliation(s)
- Yilan Wang
- Division of Genetics and Genomics, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
- The Broad Institute of Harvard and MIT, Cambridge, MA, USA
- Program in Biological and Biomedical Sciences, Harvard Medical School, Boston, MA, USA
| | - Boxun Zhao
- Division of Genetics and Genomics, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
- The Broad Institute of Harvard and MIT, Cambridge, MA, USA
- Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA, USA
| | - Jaejoon Choi
- Division of Genetics and Genomics, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
- Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Eunjung Alice Lee
- Division of Genetics and Genomics, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA.
- The Broad Institute of Harvard and MIT, Cambridge, MA, USA.
- Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA, USA.
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12
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Kim YG, Sung H, Shin HS, Kim MJ, Lee JS, Park SS, Seong MW. Intronic LINE-1 insertion in SLCO1B3 as a highly prevalent cause of rotor syndrome in East Asian population. J Hum Genet 2021; 67:71-77. [PMID: 34354231 DOI: 10.1038/s10038-021-00967-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 07/22/2021] [Accepted: 07/25/2021] [Indexed: 11/09/2022]
Abstract
Rotor syndrome is caused by digenic loss-of-function variants in SLCO1B1 and SLCO1B3 but only a few studies have reported co-occurring inactivating variants from both genes. A rotor syndrome-causing long interspersed element-1 (LINE-1) insertion in SLCO1B3 had been reported to be highly prevalent in the Japanese population but there has been no additional report. In spite of its known association with various human diseases, LINE-1 is hard to detect with current sequencing technologies. In this study, we aimed to devise a method to screen the LINE-1 insertion variant and investigate the frequency of this variant in various populations. A chimeric sequence, that was generated by concatenating the reference sequence at the junction and a part of inserted LINE-1 sequence, was searched from 725 raw sequencing data files. In cases containing the chimeric sequence, confirmatory long-range PCR and gap-PCR were performed. In total, 95 (13.1%) of 725 patients were positive for the chimeric sequence, and all were confirmed to have the SLCO1B3 LINE-1 insertion by PCR-based tests. The same chimeric sequence was searched from the 1000 Genomes Project data repository and the carrier frequency was remarkably high in the East Asian populations (10.1%), especially in Southern Han Chinese (18.5%), but almost absent in other populations. This SLCO1B3 LINE-1 insertion should be screened in a population-specific manner under suspicion of Rotor syndrome and the methods proposed in this study would enable this in a simple way.
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Affiliation(s)
- Young-Gon Kim
- Department of Laboratory Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Hobin Sung
- Department of Laboratory Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Ho Seob Shin
- Department of Laboratory Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Man Jin Kim
- Department of Laboratory Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Jee-Soo Lee
- Department of Laboratory Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Sung-Sup Park
- Department of Laboratory Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Moon-Woo Seong
- Department of Laboratory Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea.
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13
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McDonald TL, Zhou W, Castro CP, Mumm C, Switzenberg JA, Mills RE, Boyle AP. Cas9 targeted enrichment of mobile elements using nanopore sequencing. Nat Commun 2021; 12:3586. [PMID: 34117247 PMCID: PMC8196195 DOI: 10.1038/s41467-021-23918-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Accepted: 05/25/2021] [Indexed: 02/05/2023] Open
Abstract
Mobile element insertions (MEIs) are repetitive genomic sequences that contribute to genetic variation and can lead to genetic disorders. Targeted and whole-genome approaches using short-read sequencing have been developed to identify reference and non-reference MEIs; however, the read length hampers detection of these elements in complex genomic regions. Here, we pair Cas9-targeted nanopore sequencing with computational methodologies to capture active MEIs in human genomes. We demonstrate parallel enrichment for distinct classes of MEIs, averaging 44% of reads on-targeted signals and exhibiting a 13.4-54x enrichment over whole-genome approaches. We show an individual flow cell can recover most MEIs (97% L1Hs, 93% AluYb, 51% AluYa, 99% SVA_F, and 65% SVA_E). We identify seventeen non-reference MEIs in GM12878 overlooked by modern, long-read analysis pipelines, primarily in repetitive genomic regions. This work introduces the utility of nanopore sequencing for MEI enrichment and lays the foundation for rapid discovery of elusive, repetitive genetic elements.
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Affiliation(s)
- Torrin L McDonald
- Department of Human Genetics, University of Michigan, Ann Arbor, MI, USA
| | - Weichen Zhou
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, USA
| | - Christopher P Castro
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, USA
| | - Camille Mumm
- Department of Human Genetics, University of Michigan, Ann Arbor, MI, USA
| | - Jessica A Switzenberg
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, USA
| | - Ryan E Mills
- Department of Human Genetics, University of Michigan, Ann Arbor, MI, USA.
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, USA.
| | - Alan P Boyle
- Department of Human Genetics, University of Michigan, Ann Arbor, MI, USA.
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, USA.
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14
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Briggs EM, McKerrow W, Mita P, Boeke JD, Logan SK, Fenyö D. RIP-seq reveals LINE-1 ORF1p association with p-body enriched mRNAs. Mob DNA 2021; 12:5. [PMID: 33563338 PMCID: PMC7874467 DOI: 10.1186/s13100-021-00233-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 01/27/2021] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Long INterspersed Element-1 (LINE-1) is an autonomous retroelement able to "copy-and-paste" itself into new loci of the host genome through a process called retrotransposition. The LINE-1 bicistronic mRNA codes for two proteins, ORF1p, a nucleic acid chaperone, and ORF2p, a protein with endonuclease and reverse transcriptase activity. Both proteins bind LINE-1 mRNA in cis and are necessary for retrotransposition. While LINE-1 transcription is usually repressed in most healthy somatic cells through a plethora of mechanisms, ORF1p expression has been observed in nearly 50% of tumors, and new LINE-1 insertions have been documented in a similar fraction of tumors, including prostate cancer. RESULTS Here, we utilized RNA ImmunoPrecipitation (RIP) and the L1EM analysis software to identify ORF1p bound RNA in prostate cancer cells. We identified LINE-1 loci that were expressed in parental androgen sensitive and androgen independent clonal derivatives. In all androgen independent cells, we found higher levels of LINE-1 RNA, as well as unique expression patterns of LINE-1 loci. Interestingly, we observed that ORF1p bound many non-LINE-1 mRNA in all prostate cancer cell lines evaluated, and polyA RNA, and RNA localized in p-bodies were especially enriched. Furthermore, the expression levels of RNAs identified in our ORF1p RIP correlated with RNAs expressed in LINE-1 positive tumors from The Cancer Genome Atlas (TCGA). CONCLUSION Our results show a significant remodeling of LINE-1 loci expression in androgen independent cell lines when compared to parental androgen dependent cells. Additionally, we found that ORF1p bound a significant amount of non-LINE-1 mRNA, and that the enriched ORF1p bound mRNAs are also amplified in LINE-1 expressing TCGA prostate tumors, indicating the biological relevance of our findings to prostate cancer.
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Affiliation(s)
- Erica M Briggs
- Departments of Biochemistry and Molecular Pharmacology, New York University, 450 East 29th Street, Room 321, New York, NY, 10016, USA
| | - Wilson McKerrow
- Departments of Biochemistry and Molecular Pharmacology, New York University, 450 East 29th Street, Room 321, New York, NY, 10016, USA
- Institute for Systems Genetics, New York University Grossman School of Medicine, 435 East 30th St, 9th Floor, NY, 10016, New York, USA
| | - Paolo Mita
- Departments of Biochemistry and Molecular Pharmacology, New York University, 450 East 29th Street, Room 321, New York, NY, 10016, USA
- Institute for Systems Genetics, New York University Grossman School of Medicine, 435 East 30th St, 9th Floor, NY, 10016, New York, USA
| | - Jef D Boeke
- Departments of Biochemistry and Molecular Pharmacology, New York University, 450 East 29th Street, Room 321, New York, NY, 10016, USA
- Institute for Systems Genetics, New York University Grossman School of Medicine, 435 East 30th St, 9th Floor, NY, 10016, New York, USA
| | - Susan K Logan
- Departments of Biochemistry and Molecular Pharmacology, New York University, 450 East 29th Street, Room 321, New York, NY, 10016, USA.
- Urology, New York University Grossman School of Medicine, 450 East 29th Street, Room 321, New York, NY, 10016, USA.
| | - David Fenyö
- Departments of Biochemistry and Molecular Pharmacology, New York University, 450 East 29th Street, Room 321, New York, NY, 10016, USA.
- Institute for Systems Genetics, New York University Grossman School of Medicine, 435 East 30th St, 9th Floor, NY, 10016, New York, USA.
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15
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Thompson ED, Roberts NJ, Wood LD, Eshleman JR, Goggins MG, Kern SE, Klein AP, Hruban RH. The genetics of ductal adenocarcinoma of the pancreas in the year 2020: dramatic progress, but far to go. Mod Pathol 2020; 33:2544-2563. [PMID: 32704031 PMCID: PMC8375585 DOI: 10.1038/s41379-020-0629-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 07/07/2020] [Accepted: 07/07/2020] [Indexed: 12/12/2022]
Abstract
The publication of the "Pan-Cancer Atlas" by the Pan-Cancer Analysis of Whole Genomes Consortium, a partnership formed by The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC), provides a wonderful opportunity to reflect on where we stand in our understanding of the genetics of pancreatic cancer, as well as on the opportunities to translate this understanding to patient care. From germline variants that predispose to the development of pancreatic cancer, to somatic mutations that are therapeutically targetable, genetics is now providing hope, where there once was no hope, for those diagnosed with pancreatic cancer.
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Affiliation(s)
- Elizabeth D Thompson
- Department of Pathology, The Sol Goldman Pancreatic Cancer Research Center, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Oncology, The Sol Goldman Pancreatic Cancer Research Center, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Nicholas J Roberts
- Department of Pathology, The Sol Goldman Pancreatic Cancer Research Center, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Oncology, The Sol Goldman Pancreatic Cancer Research Center, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Laura D Wood
- Department of Pathology, The Sol Goldman Pancreatic Cancer Research Center, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Oncology, The Sol Goldman Pancreatic Cancer Research Center, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - James R Eshleman
- Department of Pathology, The Sol Goldman Pancreatic Cancer Research Center, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Oncology, The Sol Goldman Pancreatic Cancer Research Center, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Michael G Goggins
- Department of Pathology, The Sol Goldman Pancreatic Cancer Research Center, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Oncology, The Sol Goldman Pancreatic Cancer Research Center, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Medicine, The Sol Goldman Pancreatic Cancer Research Center, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Scott E Kern
- Department of Pathology, The Sol Goldman Pancreatic Cancer Research Center, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Oncology, The Sol Goldman Pancreatic Cancer Research Center, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Alison P Klein
- Department of Pathology, The Sol Goldman Pancreatic Cancer Research Center, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Oncology, The Sol Goldman Pancreatic Cancer Research Center, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Ralph H Hruban
- Department of Pathology, The Sol Goldman Pancreatic Cancer Research Center, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
- Department of Oncology, The Sol Goldman Pancreatic Cancer Research Center, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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16
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Grivainis M, Tang Z, Fenyö D. TranspoScope: interactive visualization of retrotransposon insertions. Bioinformatics 2020; 36:3877-3878. [PMID: 32298413 DOI: 10.1093/bioinformatics/btaa244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 01/09/2020] [Accepted: 04/09/2020] [Indexed: 11/13/2022] Open
Abstract
MOTIVATION Retrotransposition is an important force in shaping the human genome and is involved in prenatal development, disease and aging. Current genome browsers are not optimized for visualizing the experimental evidence for retrotransposon insertions. RESULTS We have developed a specialized browser to visualize the evidence for retrotransposon insertions for both targeted and whole-genome sequencing data. AVAILABILITY AND IMPLEMENTATION TranspoScope's source code, as well as installation instructions, are available at https://github.com/FenyoLab/transposcope.
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Affiliation(s)
- Mark Grivainis
- Institute for Systems Genetics.,Department of Biochemistry and Molecular Pharmacology, NYU School of Medicine, 550 1st Ave, New York, NY 10016, USA
| | - Zuojian Tang
- Institute for Systems Genetics.,Department of Biochemistry and Molecular Pharmacology, NYU School of Medicine, 550 1st Ave, New York, NY 10016, USA
| | - David Fenyö
- Institute for Systems Genetics.,Department of Biochemistry and Molecular Pharmacology, NYU School of Medicine, 550 1st Ave, New York, NY 10016, USA
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17
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Ueberham U, Arendt T. Genomic Indexing by Somatic Gene Recombination of mRNA/ncRNA - Does It Play a Role in Genomic Mosaicism, Memory Formation, and Alzheimer's Disease? Front Genet 2020; 11:370. [PMID: 32411177 PMCID: PMC7200996 DOI: 10.3389/fgene.2020.00370] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 03/25/2020] [Indexed: 12/26/2022] Open
Abstract
Recent evidence indicates that genomic individuality of neurons, characterized by DNA-content variation, is a common if not universal phenomenon in the human brain that occurs naturally but can also show aberrancies that have been linked to the pathomechanism of Alzheimer’s disease and related neurodegenerative disorders. Etiologically, this genomic mosaic has been suggested to arise from defects of cell cycle regulation that may occur either during brain development or in the mature brain after terminal differentiation of neurons. Here, we aim to draw attention towards another mechanism that can give rise to genomic individuality of neurons, with far-reaching consequences. This mechanism has its origin in the transcriptome rather than in replication defects of the genome, i.e., somatic gene recombination of RNA. We continue to develop the concept that somatic gene recombination of RNA provides a physiological process that, through integration of intronless mRNA/ncRNA into the genome, allows a particular functional state at the level of the individual neuron to be indexed. By insertion of defined RNAs in a somatic recombination process, the presence of specific mRNA transcripts within a definite temporal context can be “frozen” and can serve as an index that can be recalled at any later point in time. This allows information related to a specific neuronal state of differentiation and/or activity relevant to a memory trace to be fixed. We suggest that this process is used throughout the lifetime of each neuron and might have both advantageous and deleterious consequences.
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Affiliation(s)
- Uwe Ueberham
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - Thomas Arendt
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
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18
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Loh JW, Ha H, Lin T, Sun N, Burns KH, Xing J. Integrated Mobile Element Scanning (ME-Scan) method for identifying multiple types of polymorphic mobile element insertions. Mob DNA 2020; 11:12. [PMID: 32110248 PMCID: PMC7035633 DOI: 10.1186/s13100-020-00207-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2019] [Accepted: 02/14/2020] [Indexed: 01/29/2023] Open
Abstract
Background Mobile elements are ubiquitous components of mammalian genomes and constitute more than half of the human genome. Polymorphic mobile element insertions (pMEIs) are a major source of human genomic variation and are gaining research interest because of their involvement in gene expression regulation, genome integrity, and disease. Results Building on our previous Mobile Element Scanning (ME-Scan) protocols, we developed an integrated ME-Scan protocol to identify three major active families of human mobile elements, AluYb, L1HS, and SVA. This approach selectively amplifies insertion sites of currently active retrotransposons for Illumina sequencing. By pooling the libraries together, we can identify pMEIs from all three mobile element families in one sequencing run. To demonstrate the utility of the new ME-Scan protocol, we sequenced 12 human parent-offspring trios. Our results showed high sensitivity (> 90%) and accuracy (> 95%) of the protocol for identifying pMEIs in the human genome. In addition, we also tested the feasibility of identifying somatic insertions using the protocol. Conclusions The integrated ME-Scan protocol is a cost-effective way to identify novel pMEIs in the human genome. In addition, by developing the protocol to detect three mobile element families, we demonstrate the flexibility of the ME-Scan protocol. We present instructions for the library design, a sequencing protocol, and a computational pipeline for downstream analyses as a complete framework that will allow researchers to easily adapt the ME-Scan protocol to their own projects in other genomes.
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Affiliation(s)
- Jui Wan Loh
- 1Department of Genetics, Rutgers, the State University of New Jersey, Piscataway, NJ 08854 USA
| | - Hongseok Ha
- 1Department of Genetics, Rutgers, the State University of New Jersey, Piscataway, NJ 08854 USA.,2Human Genetic Institute of New Jersey, Rutgers, the State University of New Jersey, Piscataway, 08854 NJ USA
| | - Timothy Lin
- 1Department of Genetics, Rutgers, the State University of New Jersey, Piscataway, NJ 08854 USA
| | - Nawei Sun
- 1Department of Genetics, Rutgers, the State University of New Jersey, Piscataway, NJ 08854 USA.,2Human Genetic Institute of New Jersey, Rutgers, the State University of New Jersey, Piscataway, 08854 NJ USA
| | - Kathleen H Burns
- 3Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, 21205 MD USA
| | - Jinchuan Xing
- 1Department of Genetics, Rutgers, the State University of New Jersey, Piscataway, NJ 08854 USA.,2Human Genetic Institute of New Jersey, Rutgers, the State University of New Jersey, Piscataway, 08854 NJ USA
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19
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McKerrow W, Tang Z, Steranka JP, Payer LM, Boeke JD, Keefe D, Fenyö D, Burns KH, Liu C. Human transposon insertion profiling by sequencing (TIPseq) to map LINE-1 insertions in single cells. Philos Trans R Soc Lond B Biol Sci 2020; 375:20190335. [PMID: 32075555 PMCID: PMC7061987 DOI: 10.1098/rstb.2019.0335] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Long interspersed element-1 (LINE-1, L1) sequences, which comprise about 17% of human genome, are the product of one of the most active types of mobile DNAs in modern humans. LINE-1 insertion alleles can cause inherited and de novo genetic diseases, and LINE-1-encoded proteins are highly expressed in some cancers. Genome-wide LINE-1 mapping in single cells could be useful for defining somatic and germline retrotransposition rates, and for enabling studies to characterize tumour heterogeneity, relate insertions to transcriptional and epigenetic effects at the cellular level, or describe cellular phylogenies in development. Our laboratories have reported a genome-wide LINE-1 insertion site mapping method for bulk DNA, named transposon insertion profiling by sequencing (TIPseq). There have been significant barriers applying LINE-1 mapping to single cells, owing to the chimeric artefacts and features of repetitive sequences. Here, we optimize a modified TIPseq protocol and show its utility for LINE-1 mapping in single lymphoblastoid cells. Results from single-cell TIPseq experiments compare well to known LINE-1 insertions found by whole-genome sequencing and TIPseq on bulk DNA. Among the several approaches we tested, whole-genome amplification by multiple displacement amplification followed by restriction enzyme digestion, vectorette ligation and LINE-1-targeted PCR had the best assay performance. This article is part of a discussion meeting issue 'Crossroads between transposons and gene regulation'.
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Affiliation(s)
- Wilson McKerrow
- Institute for Systems Genetics and Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, USA
| | - Zuojian Tang
- Institute for Systems Genetics and Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, USA
| | - Jared P Steranka
- Department of Pathology, Johns Hopkins University School of Medicine, 733N Broadway, Baltimore, MD 21205, USA
| | - Lindsay M Payer
- Department of Pathology, Johns Hopkins University School of Medicine, 733N Broadway, Baltimore, MD 21205, USA
| | - Jef D Boeke
- Institute for Systems Genetics and Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, USA
| | - David Keefe
- Department of Obstetrics and Gynecology, New York University Langone School of Medicine, 462 First Avenue, New York, NY 10016, USA.,Department of Cell Biology, New York University Langone School of Medicine, 462 First Avenue, New York, NY 10016, USA
| | - David Fenyö
- Institute for Systems Genetics and Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, USA
| | - Kathleen H Burns
- Department of Pathology, Johns Hopkins University School of Medicine, 733N Broadway, Baltimore, MD 21205, USA.,McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, 733N Broadway, Baltimore, MD 21205, USA.,High Throughput (HiT) Biology Center, Johns Hopkins University School of Medicine, 733N Broadway, Baltimore, MD 21205, USA.,Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, 401N Broadway, Baltimore, MD 21231, USA
| | - Chunhong Liu
- Department of Pathology, Johns Hopkins University School of Medicine, 733N Broadway, Baltimore, MD 21205, USA
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20
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Ardeljan D, Steranka JP, Liu C, Li Z, Taylor MS, Payer LM, Gorbounov M, Sarnecki JS, Deshpande V, Hruban RH, Boeke JD, Fenyö D, Wu PH, Smogorzewska A, Holland AJ, Burns KH. Cell fitness screens reveal a conflict between LINE-1 retrotransposition and DNA replication. Nat Struct Mol Biol 2020; 27:168-178. [PMID: 32042151 PMCID: PMC7080318 DOI: 10.1038/s41594-020-0372-1] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Accepted: 12/31/2019] [Indexed: 12/18/2022]
Abstract
LINE-1 retrotransposon overexpression is a hallmark of human cancers. We identified a colorectal cancer wherein a fast-growing tumor subclone downregulated LINE-1, prompting us to examine how LINE-1 expression affects cell growth. We find that nontransformed cells undergo a TP53-dependent growth arrest and activate interferon signaling in response to LINE-1. TP53 inhibition allows LINE-1+ cells to grow, and genome-wide-knockout screens show that these cells require replication-coupled DNA-repair pathways, replication-stress signaling and replication-fork restart factors. Our findings demonstrate that LINE-1 expression creates specific molecular vulnerabilities and reveal a retrotransposition-replication conflict that may be an important determinant of cancer growth.
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Affiliation(s)
- Daniel Ardeljan
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
- Medical Scientist Training Program, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
| | - Jared P Steranka
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Chunhong Liu
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Zhi Li
- Institute for Systems Genetics and Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York City, NY, USA
| | - Martin S Taylor
- Department of Pathology, Massachusetts General Hospital, Boston, MA, USA
| | - Lindsay M Payer
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Mikhail Gorbounov
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jacob S Sarnecki
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Vikram Deshpande
- Department of Pathology, Massachusetts General Hospital, Boston, MA, USA
| | - Ralph H Hruban
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jef D Boeke
- Institute for Systems Genetics and Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York City, NY, USA
| | - David Fenyö
- Institute for Systems Genetics and Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York City, NY, USA
| | - Pei-Hsun Wu
- Johns Hopkins Physical Sciences Oncology Center, Johns Hopkins University, Baltimore, MD, USA
- Institute for NanoBiotechnology, Johns Hopkins University, Baltimore, MD, USA
| | - Agata Smogorzewska
- Laboratory of Genome Maintenance, The Rockefeller University, New York City, NY, USA
| | - Andrew J Holland
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Kathleen H Burns
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
- Sydney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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21
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Ardeljan D, Wang X, Oghbaie M, Taylor MS, Husband D, Deshpande V, Steranka JP, Gorbounov M, Yang WR, Sie B, Larman HB, Jiang H, Molloy KR, Altukhov I, Li Z, McKerrow W, Fenyö D, Burns KH, LaCava J. LINE-1 ORF2p expression is nearly imperceptible in human cancers. Mob DNA 2019; 11:1. [PMID: 31892958 PMCID: PMC6937734 DOI: 10.1186/s13100-019-0191-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Accepted: 11/22/2019] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Long interspersed element-1 (LINE-1, L1) is the major driver of mobile DNA activity in modern humans. When expressed, LINE-1 loci produce bicistronic transcripts encoding two proteins essential for retrotransposition, ORF1p and ORF2p. Many types of human cancers are characterized by L1 promoter hypomethylation, L1 transcription, L1 ORF1p protein expression, and somatic L1 retrotransposition. ORF2p encodes the endonuclease and reverse transcriptase activities required for L1 retrotransposition. Its expression is poorly characterized in human tissues and cell lines. RESULTS We report mass spectrometry-based tumor proteome profiling studies wherein ORF2p eludes detection. To test whether ORF2p could be detected with specific reagents, we developed and validated five rabbit monoclonal antibodies with immunoreactivity for specific epitopes on the protein. These reagents readily detect ectopic ORF2p expressed from bicistronic L1 constructs. However, endogenous ORF2p is not detected in human tumor samples or cell lines by western blot, immunoprecipitation, or immunohistochemistry despite high levels of ORF1p expression. Moreover, we report endogenous ORF1p-associated interactomes, affinity isolated from colorectal cancers, wherein we similarly fail to detect ORF2p. These samples include primary tumors harboring hundreds of somatically acquired L1 insertions. The new data are available via ProteomeXchange with identifier PXD013743. CONCLUSIONS Although somatic retrotransposition provides unequivocal genetic evidence for the expression of ORF2p in human cancers, we are unable to directly measure its presence using several standard methods. Experimental systems have previously indicated an unequal stoichiometry between ORF1p and ORF2p, but in vivo, the expression of these two proteins may be more strikingly uncoupled. These findings are consistent with observations that ORF2p is not tolerable for cell growth.
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Affiliation(s)
- Daniel Ardeljan
- McKusick Nathans Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205 USA
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21205 USA
| | - Xuya Wang
- Institute for Systems Genetics, Department of Biochemistry and Molecular Pharmacology, NYU School of Medicine, New York, NY 10016 USA
| | - Mehrnoosh Oghbaie
- Laboratory of Cellular and Structural Biology, The Rockefeller University, New York, NY 10065 USA
| | - Martin S. Taylor
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21205 USA
- Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114 USA
| | - David Husband
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21205 USA
| | - Vikram Deshpande
- Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114 USA
| | - Jared P. Steranka
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21205 USA
| | - Mikhail Gorbounov
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21205 USA
| | - Wan Rou Yang
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21205 USA
| | - Brandon Sie
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21205 USA
| | - H. Benjamin Larman
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21205 USA
| | - Hua Jiang
- Laboratory of Cellular and Structural Biology, The Rockefeller University, New York, NY 10065 USA
| | - Kelly R. Molloy
- Laboratory of Mass Spectrometry and Gaseous Ion Chemistry, The Rockefeller University, New York, NY 10065 USA
| | - Ilya Altukhov
- Moscow Institute of Physics and Technology, Dolgoprudny, 141701 Russia
| | - Zhi Li
- Institute for Systems Genetics, Department of Biochemistry and Molecular Pharmacology, NYU School of Medicine, New York, NY 10016 USA
| | - Wilson McKerrow
- Institute for Systems Genetics, Department of Biochemistry and Molecular Pharmacology, NYU School of Medicine, New York, NY 10016 USA
| | - David Fenyö
- Institute for Systems Genetics, Department of Biochemistry and Molecular Pharmacology, NYU School of Medicine, New York, NY 10016 USA
| | - Kathleen H. Burns
- McKusick Nathans Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205 USA
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21205 USA
| | - John LaCava
- Laboratory of Cellular and Structural Biology, The Rockefeller University, New York, NY 10065 USA
- European Research Institute for the Biology of Ageing, University Medical Center Groningen, Groningen, 9713 AV The Netherlands
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22
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Tam OH, Ostrow LW, Gale Hammell M. Diseases of the nERVous system: retrotransposon activity in neurodegenerative disease. Mob DNA 2019; 10:32. [PMID: 31372185 PMCID: PMC6659213 DOI: 10.1186/s13100-019-0176-1] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 07/18/2019] [Indexed: 12/13/2022] Open
Abstract
Transposable Elements (TEs) are mobile genetic elements whose sequences constitute nearly half of the human genome. Each TE copy can be present in hundreds to thousands of locations within the genome, complicating the genetic and genomic studies of these highly repetitive sequences. The recent development of better tools for evaluating TE derived sequences in genomic studies has enabled an increasing appreciation for the contribution of TEs to human development and disease. While some TEs have contributed novel and beneficial host functions, this review will summarize the evidence for detrimental TE activity in neurodegenerative disorders. Much of the evidence for pathogenicity implicates endogenous retroviruses (ERVs), a subset of TEs that entered the genome by retroviral infections of germline cells in our evolutionary ancestors and have since been passed down as a substantial fraction of the human genome. Human specific ERVs (HERVs) represent some of the youngest ERVs in the genome, and thus are presumed to retain greater function and resultant pathogenic potential.
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Affiliation(s)
- Oliver H Tam
- 1Quantitative Biology, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724 USA
| | - Lyle W Ostrow
- 2Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205 USA
| | - Molly Gale Hammell
- 1Quantitative Biology, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724 USA
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