1
|
Carbonell-Sala S, Perteghella T, Lagarde J, Nishiyori H, Palumbo E, Arnan C, Takahashi H, Carninci P, Uszczynska-Ratajczak B, Guigó R. CapTrap-seq: a platform-agnostic and quantitative approach for high-fidelity full-length RNA sequencing. Nat Commun 2024; 15:5278. [PMID: 38937428 PMCID: PMC11211341 DOI: 10.1038/s41467-024-49523-3] [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: 07/12/2023] [Accepted: 06/10/2024] [Indexed: 06/29/2024] Open
Abstract
Long-read RNA sequencing is essential to produce accurate and exhaustive annotation of eukaryotic genomes. Despite advancements in throughput and accuracy, achieving reliable end-to-end identification of RNA transcripts remains a challenge for long-read sequencing methods. To address this limitation, we develop CapTrap-seq, a cDNA library preparation method, which combines the Cap-trapping strategy with oligo(dT) priming to detect 5' capped, full-length transcripts. In our study, we evaluate the performance of CapTrap-seq alongside other widely used RNA-seq library preparation protocols in human and mouse tissues, employing both ONT and PacBio sequencing technologies. To explore the quantitative capabilities of CapTrap-seq and its accuracy in reconstructing full-length RNA molecules, we implement a capping strategy for synthetic RNA spike-in sequences that mimics the natural 5'cap formation. Our benchmarks, incorporating the Long-read RNA-seq Genome Annotation Assessment Project (LRGASP) data, demonstrate that CapTrap-seq is a competitive, platform-agnostic RNA library preparation method for generating full-length transcript sequences.
Collapse
Affiliation(s)
- Sílvia Carbonell-Sala
- Centre for Genomic Regulation (CRG), the Barcelona Institute of Science and Technology, Barcelona, Catalonia, Spain
| | - Tamara Perteghella
- Centre for Genomic Regulation (CRG), the Barcelona Institute of Science and Technology, Barcelona, Catalonia, Spain
- Universitat Pompeu Fabra, Barcelona, Catalonia, Spain
| | - Julien Lagarde
- Centre for Genomic Regulation (CRG), the Barcelona Institute of Science and Technology, Barcelona, Catalonia, Spain
- Flomics Biotech, SL, Carrer de Roc Boronat 31, 08005, Barcelona, Catalonia, Spain
| | - Hiromi Nishiyori
- Laboratory for Transcriptome Technology, RIKEN Center for Integrative Medical Sciences (IMS), Yokohama, Kanagawa, Japan
| | - Emilio Palumbo
- Centre for Genomic Regulation (CRG), the Barcelona Institute of Science and Technology, Barcelona, Catalonia, Spain
| | - Carme Arnan
- Centre for Genomic Regulation (CRG), the Barcelona Institute of Science and Technology, Barcelona, Catalonia, Spain
| | - Hazuki Takahashi
- Laboratory for Transcriptome Technology, RIKEN Center for Integrative Medical Sciences (IMS), Yokohama, Kanagawa, Japan
| | - Piero Carninci
- Laboratory for Transcriptome Technology, RIKEN Center for Integrative Medical Sciences (IMS), Yokohama, Kanagawa, Japan
- Human Technopole, Milan, Italy
| | - Barbara Uszczynska-Ratajczak
- Centre for Genomic Regulation (CRG), the Barcelona Institute of Science and Technology, Barcelona, Catalonia, Spain.
- Department of Computational Biology of Noncoding RNA, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan, Poland.
| | - Roderic Guigó
- Centre for Genomic Regulation (CRG), the Barcelona Institute of Science and Technology, Barcelona, Catalonia, Spain.
- Universitat Pompeu Fabra, Barcelona, Catalonia, Spain.
| |
Collapse
|
2
|
Wang ZY, Ge LP, Ouyang Y, Jin X, Jiang YZ. Targeting transposable elements in cancer: developments and opportunities. Biochim Biophys Acta Rev Cancer 2024; 1879:189143. [PMID: 38936517 DOI: 10.1016/j.bbcan.2024.189143] [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: 12/07/2023] [Revised: 05/23/2024] [Accepted: 06/19/2024] [Indexed: 06/29/2024]
Abstract
Transposable elements (TEs), comprising nearly 50% of the human genome, have transitioned from being perceived as "genomic junk" to key players in cancer progression. Contemporary research links TE regulatory disruptions with cancer development, underscoring their therapeutic potential. Advances in long-read sequencing, computational analytics, single-cell sequencing, proteomics, and CRISPR-Cas9 technologies have enriched our understanding of TEs' clinical implications, notably their impact on genome architecture, gene regulation, and evolutionary processes. In cancer, TEs, including long interspersed element-1 (LINE-1), Alus, and long terminal repeat (LTR) elements, demonstrate altered patterns, influencing both tumorigenic and tumor-suppressive mechanisms. TE-derived nucleic acids and tumor antigens play critical roles in tumor immunity, bridging innate and adaptive responses. Given their central role in oncology, TE-targeted therapies, particularly through reverse transcriptase inhibitors and epigenetic modulators, represent a novel avenue in cancer treatment. Combining these TE-focused strategies with existing chemotherapy or immunotherapy regimens could enhance efficacy and offer a new dimension in cancer treatment. This review delves into recent TE detection advancements, explores their multifaceted roles in tumorigenesis and immune regulation, discusses emerging diagnostic and therapeutic approaches centered on TEs, and anticipates future directions in cancer research.
Collapse
Affiliation(s)
- Zi-Yu Wang
- Department of Breast Surgery, Fudan University Shanghai Cancer Center; Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Li-Ping Ge
- Department of Breast Surgery, Fudan University Shanghai Cancer Center; Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Yang Ouyang
- Department of Breast Surgery, Fudan University Shanghai Cancer Center; Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Xi Jin
- Department of Breast Surgery, Fudan University Shanghai Cancer Center; Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Yi-Zhou Jiang
- Department of Breast Surgery, Fudan University Shanghai Cancer Center; Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, China.
| |
Collapse
|
3
|
Gao D, Fox-Fogle E. Identification of transcriptionally active transposons in Barley. BMC Genom Data 2023; 24:64. [PMID: 37925398 PMCID: PMC10625261 DOI: 10.1186/s12863-023-01170-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 10/30/2023] [Indexed: 11/06/2023] Open
Abstract
BACKGROUND The genomes of many major crops including barley (Hordeum vulgare) consist of numerous transposons. Despite their important roles in crop genome evolution and morphological variations, most of these elements are silent or truncated and unable to be mobile in host genomes. Thus far, only a very limited number of active transposons were identified in plants. RESULTS We analyzed the barley full-length cDNA (FLcDNA) sequences and detected 71 unique FLcDNAs exhibiting significant sequence similarity to the extant transposase proteins. These FLcDNAs were then used to search against the genome of a malting barley cultivar 'Morex', seven new intact transposons were identified. Sequence alignments indicated that six intact transposons contained the entire FLcDNAs whereas another one served as 3' untranslated region (3' UTR) of a barley gene. Our reverse transcription-PCR (RT-PCR) experiment further confirmed the expression of these six transposons and revealed their differential expression. We conducted genome-wide transposon comparisons and detected polymorphisms of three transposon families between the genomes of 'Morex' and other three genotypes including the wild barley (Hordeum spontaneum, B1K-04-12) and two cultivated barley varieties, 'Golden Promise' and 'Lasa Goumang'. Lastly, we screened the transcripts of all annotated barley genes and found that some transposons may serve as the coding regions (CDSs) or UTRs of barley genes. CONCLUSION We identified six newly expressed transposons in the barley genome and revealed the recent mobility of three transposon families. Our efforts provide a valuable resource for understanding the effects of transposons on barley genome evolution and for developing novel molecular tools for barley genetic improvement and other research.
Collapse
Affiliation(s)
- Dongying Gao
- Small Grains and Potato Germplasm Research Unit, USDA-ARS, Aberdeen, ID, 83210, USA.
| | - Emma Fox-Fogle
- Small Grains and Potato Germplasm Research Unit, USDA-ARS, Aberdeen, ID, 83210, USA
- National Agricultural Statistical Service, USDA, Olympia, WA, 98501, USA
| |
Collapse
|
4
|
Zhu J, Guo Q, Choi M, Liang Z, Yuen KWY. Centromeric and pericentric transcription and transcripts: their intricate relationships, regulation, and functions. Chromosoma 2023:10.1007/s00412-023-00801-x. [PMID: 37401943 PMCID: PMC10356649 DOI: 10.1007/s00412-023-00801-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 05/22/2023] [Accepted: 05/23/2023] [Indexed: 07/05/2023]
Abstract
Centromeres are no longer considered to be silent. Both centromeric and pericentric transcription have been discovered, and their RNA transcripts have been characterized and probed for functions in numerous monocentric model organisms recently. Here, we will discuss the challenges in centromere transcription studies due to the repetitive nature and sequence similarity in centromeric and pericentric regions. Various technological breakthroughs have helped to tackle these challenges and reveal unique features of the centromeres and pericentromeres. We will briefly introduce these techniques, including third-generation long-read DNA and RNA sequencing, protein-DNA and RNA-DNA interaction detection methods, and epigenomic and nucleosomal mapping techniques. Interestingly, some newly analyzed repeat-based holocentromeres also resemble the architecture and the transcription behavior of monocentromeres. We will summarize evidences that support the functions of the transcription process and stalling, and those that support the functions of the centromeric and pericentric RNAs. The processing of centromeric and pericentric RNAs into multiple variants and their diverse structures may also provide clues to their functions. How future studies may address the separation of functions of specific centromeric transcription steps, processing pathways, and the transcripts themselves will also be discussed.
Collapse
Affiliation(s)
- Jing Zhu
- School of Biological Sciences, The University of Hong Kong, Kadoorie Biological Sciences Building, Pokfulam Road, Hong Kong, China
| | - Qiao Guo
- School of Biological Sciences, The University of Hong Kong, Kadoorie Biological Sciences Building, Pokfulam Road, Hong Kong, China
- Institute of Molecular Physiology, Gaoke Innovation Center, Shenzhen Bay Laboratory, Guangming District, Guangqiao Road, Shenzhen, China
| | - Minjun Choi
- School of Biological Sciences, The University of Hong Kong, Kadoorie Biological Sciences Building, Pokfulam Road, Hong Kong, China
| | - Zhoubin Liang
- Institute of Molecular Physiology, Gaoke Innovation Center, Shenzhen Bay Laboratory, Guangming District, Guangqiao Road, Shenzhen, China
| | - Karen Wing Yee Yuen
- School of Biological Sciences, The University of Hong Kong, Kadoorie Biological Sciences Building, Pokfulam Road, Hong Kong, China.
| |
Collapse
|
5
|
Carbonell-Sala S, Lagarde J, Nishiyori H, Palumbo E, Arnan C, Takahashi H, Carninci P, Uszczynska-Ratajczak B, Guigó R. CapTrap-Seq: A platform-agnostic and quantitative approach for high-fidelity full-length RNA transcript sequencing. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.16.543444. [PMID: 37398314 PMCID: PMC10312720 DOI: 10.1101/2023.06.16.543444] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Long-read RNA sequencing is essential to produce accurate and exhaustive annotation of eukaryotic genomes. Despite advancements in throughput and accuracy, achieving reliable end-to-end identification of RNA transcripts remains a challenge for long-read sequencing methods. To address this limitation, we developed CapTrap-seq, a cDNA library preparation method, which combines the Cap-trapping strategy with oligo(dT) priming to detect 5'capped, full-length transcripts, together with the data processing pipeline LyRic. We benchmarked CapTrap-seq and other popular RNA-seq library preparation protocols in a number of human tissues using both ONT and PacBio sequencing. To assess the accuracy of the transcript models produced, we introduced a capping strategy for synthetic RNA spike-in sequences that mimics the natural 5'cap formation in RNA spike-in molecules. We found that the vast majority (up to 90%) of transcript models that LyRic derives from CapTrap-seq reads are full-length. This makes it possible to produce highly accurate annotations with minimal human intervention.
Collapse
|
6
|
Prawer YDJ, Gleeson J, De Paoli-Iseppi R, Clark MB. Pervasive effects of RNA degradation on Nanopore direct RNA sequencing. NAR Genom Bioinform 2023; 5:lqad060. [PMID: 37305170 PMCID: PMC10251640 DOI: 10.1093/nargab/lqad060] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 04/18/2023] [Accepted: 06/07/2023] [Indexed: 06/13/2023] Open
Abstract
Oxford Nanopore direct RNA sequencing (DRS) is capable of sequencing complete RNA molecules and accurately measuring gene and isoform expression. However, as DRS is designed to profile intact RNA, expression quantification may be more heavily dependent upon RNA integrity than alternative RNA sequencing methodologies. It is currently unclear how RNA degradation impacts DRS or whether it can be corrected for. To assess the impact of RNA integrity on DRS, we performed a degradation time series using SH-SY5Y neuroblastoma cells. Our results demonstrate that degradation is a significant and pervasive factor that can bias DRS measurements, including a reduction in library complexity resulting in an overrepresentation of short genes and isoforms. Degradation also biases differential expression analyses; however, we find that explicit correction can almost fully recover meaningful biological signal. In addition, DRS provided less biased profiling of partially degraded samples than Nanopore PCR-cDNA sequencing. Overall, we find that samples with RNA integrity number (RIN) > 9.5 can be treated as undegraded and samples with RIN > 7 can be utilized for DRS with appropriate correction. These results establish the suitability of DRS for a wide range of samples, including partially degraded in vivo clinical and post-mortem samples, while limiting the confounding effect of degradation on expression quantification.
Collapse
Affiliation(s)
- Yair D J Prawer
- Centre for Stem Cell Systems, Department of Anatomy and Physiology, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Josie Gleeson
- Centre for Stem Cell Systems, Department of Anatomy and Physiology, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Ricardo De Paoli-Iseppi
- Centre for Stem Cell Systems, Department of Anatomy and Physiology, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Michael B Clark
- To whom correspondence should be addressed. Tel: +61 3 9035 3669;
| |
Collapse
|
7
|
Gvozdenov Z. Genome-Wide Mapping of 5' Isoforms with 5'-Seq. Curr Protoc 2023; 3:e750. [PMID: 37084173 DOI: 10.1002/cpz1.750] [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] [Indexed: 04/22/2023]
Abstract
The transcriptome is far more complex than previously assumed. Transcripts from the same gene can differ in terms of transcription start site, transcription end site, or pattern of splicing, and growing evidence supports the functional importance of these distinct transcript isoforms. Easily identifying these isoforms experimentally via library construction and high-throughput sequencing is crucial. Current library construction methods for identifying transcription start sites (5' transcript isoforms) involve large number of steps and (expensive) reagents, utilization of cDNA intermediates for adapter ligation, and are less suitable for studying low-abundance isoforms. Here, I describe a quick protocol for the generation of sequencing libraries to define capped 5' isoforms (5'-Seq) of various abundances in yeast and suggest a 5' isoform data analysis pipeline. The protocol relies on the utilization of a dephosphorylation-decapping method (oligo-capping) to generate a sequencing library from mRNA fragments and is a simplification of previously published 5' isoform protocols in terms of the handling steps, time, and cost. This method is exemplified using Saccharomyces cerevisiae mRNA, but it can be applied to various cellular conditions to study the effects of 5' transcript isoforms on transcriptional and/or translational regulation. © 2023 Wiley Periodicals LLC. Basic Protocol: Construction of a DNA sequencing library from capped 5' isoforms Support Protocol: Sequencing data analysis.
Collapse
Affiliation(s)
- Zlata Gvozdenov
- Harvard Medical School, Department of Biological Chemistry and Molecular Pharmacology, Boston, Massachusetts
| |
Collapse
|
8
|
Santos D, Feng M, Kolliopoulou A, Taning CNT, Sun J, Swevers L. What Are the Functional Roles of Piwi Proteins and piRNAs in Insects? INSECTS 2023; 14:insects14020187. [PMID: 36835756 PMCID: PMC9962485 DOI: 10.3390/insects14020187] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Revised: 02/09/2023] [Accepted: 02/11/2023] [Indexed: 06/01/2023]
Abstract
Research on Piwi proteins and piRNAs in insects has focused on three experimental models: oogenesis and spermatogenesis in Drosophila melanogaster, the antiviral response in Aedes mosquitoes and the molecular analysis of primary and secondary piRNA biogenesis in Bombyx mori-derived BmN4 cells. Significant unique and complementary information has been acquired and has led to a greater appreciation of the complexity of piRNA biogenesis and Piwi protein function. Studies performed in other insect species are emerging and promise to add to the current state of the art on the roles of piRNAs and Piwi proteins. Although the primary role of the piRNA pathway is genome defense against transposons, particularly in the germline, recent findings also indicate an expansion of its functions. In this review, an extensive overview is presented of the knowledge of the piRNA pathway that so far has accumulated in insects. Following a presentation of the three major models, data from other insects were also discussed. Finally, the mechanisms for the expansion of the function of the piRNA pathway from transposon control to gene regulation were considered.
Collapse
Affiliation(s)
- Dulce Santos
- Research Group of Molecular Developmental Physiology and Signal Transduction, Division of Animal Physiology and Neurobiology, Department of Biology, KU Leuven, Naamsestraat 59, 3000 Leuven, Belgium
| | - Min Feng
- Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou 510642, China
| | - Anna Kolliopoulou
- Insect Molecular Genetics and Biotechnology, Institute of Biosciences & Applications, National Centre for Scientific Research “Demokritos”, Aghia Paraskevi, 15341 Athens, Greece
| | - Clauvis N. T. Taning
- Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, 9000 Ghent, Belgium
| | - Jingchen Sun
- Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou 510642, China
| | - Luc Swevers
- Insect Molecular Genetics and Biotechnology, Institute of Biosciences & Applications, National Centre for Scientific Research “Demokritos”, Aghia Paraskevi, 15341 Athens, Greece
| |
Collapse
|
9
|
Ding D, Zhang J, Du B, Wang X, Hou L, Guo S, Chen B, Kang L. Non-canonical function of an Hif-1α splice variant contributes to the sustained flight of locusts. eLife 2022; 11:74554. [PMID: 36039636 PMCID: PMC9427102 DOI: 10.7554/elife.74554] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 07/11/2022] [Indexed: 12/30/2022] Open
Abstract
The hypoxia inducible factor (Hif) pathway is functionally conserved across metazoans in modulating cellular adaptations to hypoxia. However, the functions of this pathway under aerobic physiological conditions are rarely investigated. Here, we show that Hif-1α2, a locust Hif-1α isoform, does not induce canonical hypoxic responses but functions as a specific regulator of locust flight, which is a completely aerobic physiological process. Two Hif-1α splice variants were identified in locusts, a ubiquitously expressed Hif-1α1 and a muscle-predominantly expressed Hif-1α2. Hif-1α1 that induces typical hypoxic responses upon hypoxia exposure remains inactive during flight. By contrast, the expression of Hif-1α2, which lacks C-terminal transactivation domain, is less sensitive to oxygen tension but induced extensively by flying. Hif-1α2 regulates physiological processes involved in glucose metabolism and antioxidation during flight and sustains flight endurance by maintaining redox homeostasis through upregulating the production of a reactive oxygen species (ROS) quencher, DJ-1. Overall, this study reveals a novel Hif-mediated mechanism underlying prolonged aerobic physiological activity.
Collapse
Affiliation(s)
- Ding Ding
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Jie Zhang
- Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing, China
| | - Baozhen Du
- Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing, China
| | - Xuanzhao Wang
- School of Life Science, Hebei University, Baoding, China
| | - Li Hou
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Siyuan Guo
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Bing Chen
- School of Life Science, Hebei University, Baoding, China
| | - Le Kang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing, China.,School of Life Science, Hebei University, Baoding, China
| |
Collapse
|
10
|
Lee Y, Ha U, Moon S. Ongoing endeavors to detect mobilization of transposable elements. BMB Rep 2022. [PMID: 35725016 PMCID: PMC9340088 DOI: 10.5483/bmbrep.2022.55.7.088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Transposable elements (TEs) are DNA sequences capable of mobilization from one location to another in the genome. Since the discovery of ‘Dissociation (Dc) locus’ by Barbara McClintock in maize (1), mounting evidence in the era of genomics indicates that a significant fraction of most eukaryotic genomes is composed of TE sequences, involving in various aspects of biological processes such as development, physiology, diseases and evolution. Although technical advances in genomics have discovered numerous functional impacts of TE across species, our understanding of TEs is still ongoing process due to challenges resulted from complexity and abundance of TEs in the genome. In this mini-review, we briefly summarize biology of TEs and their impacts on the host genome, emphasizing importance of understanding TE landscape in the genome. Then, we introduce recent endeavors especially in vivo retrotransposition assays and long read sequencing technology for identifying de novo insertions/TE polymorphism, which will broaden our knowledge of extraordinary relationship between genomic cohabitants and their host.
Collapse
Affiliation(s)
- Yujeong Lee
- Department of Biological Sciences, Kangwon National University, Chuncheon 24341, Korea
| | - Una Ha
- Department of Biological Sciences, Kangwon National University, Chuncheon 24341, Korea
| | - Sungjin Moon
- Department of Biological Sciences, Kangwon National University, Chuncheon 24341, Korea
| |
Collapse
|
11
|
Tombácz D, Kakuk B, Torma G, Csabai Z, Gulyás G, Tamás V, Zádori Z, Jefferson VA, Meyer F, Boldogkői Z. In-Depth Temporal Transcriptome Profiling of an Alphaherpesvirus Using Nanopore Sequencing. Viruses 2022; 14:v14061289. [PMID: 35746760 PMCID: PMC9229804 DOI: 10.3390/v14061289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 06/05/2022] [Accepted: 06/08/2022] [Indexed: 12/10/2022] Open
Abstract
In this work, a long-read sequencing (LRS) technique based on the Oxford Nanopore Technology MinION platform was used for quantifying and kinetic characterization of the poly(A) fraction of bovine alphaherpesvirus type 1 (BoHV-1) lytic transcriptome across a 12-h infection period. Amplification-based LRS techniques frequently generate artefactual transcription reads and are biased towards the production of shorter amplicons. To avoid these undesired effects, we applied direct cDNA sequencing, an amplification-free technique. Here, we show that a single promoter can produce multiple transcription start sites whose distribution patterns differ among the viral genes but are similar in the same gene at different timepoints. Our investigations revealed that the circ gene is expressed with immediate–early (IE) kinetics by utilizing a special mechanism based on the use of the promoter of another IE gene (bicp4) for the transcriptional control. Furthermore, we detected an overlap between the initiation of DNA replication and the transcription from the bicp22 gene, which suggests an interaction between the two molecular machineries. This study developed a generally applicable LRS-based method for the time-course characterization of transcriptomes of any organism.
Collapse
Affiliation(s)
- Dóra Tombácz
- Department of Medical Biology, Albert Szent-Györgyi Medical School, University of Szeged, Somogyi u. 4, 6720 Szeged, Hungary; (D.T.); (B.K.); (G.T.); (Z.C.); (G.G.)
| | - Balázs Kakuk
- Department of Medical Biology, Albert Szent-Györgyi Medical School, University of Szeged, Somogyi u. 4, 6720 Szeged, Hungary; (D.T.); (B.K.); (G.T.); (Z.C.); (G.G.)
| | - Gábor Torma
- Department of Medical Biology, Albert Szent-Györgyi Medical School, University of Szeged, Somogyi u. 4, 6720 Szeged, Hungary; (D.T.); (B.K.); (G.T.); (Z.C.); (G.G.)
| | - Zsolt Csabai
- Department of Medical Biology, Albert Szent-Györgyi Medical School, University of Szeged, Somogyi u. 4, 6720 Szeged, Hungary; (D.T.); (B.K.); (G.T.); (Z.C.); (G.G.)
| | - Gábor Gulyás
- Department of Medical Biology, Albert Szent-Györgyi Medical School, University of Szeged, Somogyi u. 4, 6720 Szeged, Hungary; (D.T.); (B.K.); (G.T.); (Z.C.); (G.G.)
| | - Vivien Tamás
- Institute for Veterinary Medical Research, Centre for Agricultural Research, Hungária krt. 21, 1143 Budapest, Hungary; (V.T.); (Z.Z.)
| | - Zoltán Zádori
- Institute for Veterinary Medical Research, Centre for Agricultural Research, Hungária krt. 21, 1143 Budapest, Hungary; (V.T.); (Z.Z.)
| | - Victoria A. Jefferson
- Department of Biochemistry & Molecular Biology, Entomology & Plant Pathology, Mississippi State University, 408 Dorman P.O. Box 9655, 32 Creelman St., Starkville, MS 39762, USA; (V.A.J.); (F.M.)
| | - Florencia Meyer
- Department of Biochemistry & Molecular Biology, Entomology & Plant Pathology, Mississippi State University, 408 Dorman P.O. Box 9655, 32 Creelman St., Starkville, MS 39762, USA; (V.A.J.); (F.M.)
| | - Zsolt Boldogkői
- Department of Medical Biology, Albert Szent-Györgyi Medical School, University of Szeged, Somogyi u. 4, 6720 Szeged, Hungary; (D.T.); (B.K.); (G.T.); (Z.C.); (G.G.)
- Correspondence:
| |
Collapse
|
12
|
Wongsurawat T, Jenjaroenpun P, Wanchai V, Nookaew I. Native RNA or cDNA Sequencing for Transcriptomic Analysis: A Case Study on Saccharomyces cerevisiae. Front Bioeng Biotechnol 2022; 10:842299. [PMID: 35497361 PMCID: PMC9039254 DOI: 10.3389/fbioe.2022.842299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 03/01/2022] [Indexed: 11/13/2022] Open
Abstract
Direct sequencing of single molecules through nanopores allows for accurate quantification and full-length characterization of native RNA or complementary DNA (cDNA) without amplification. Both nanopore-based native RNA and cDNA approaches involve complex transcriptome procedures at a lower cost. However, there are several differences between the two approaches. In this study, we perform matched native RNA sequencing and cDNA sequencing to enable relevant comparisons and evaluation. Using Saccharomyces cerevisiae, a eukaryotic model organism widely used in industrial biotechnology, two different growing conditions are considered for comparison, including the poly-A messenger RNA isolated from yeast cells grown in minimum media under respirofermentative conditions supplemented with glucose (glucose growth conditions) and from cells that had shifted to ethanol as a carbon source (ethanol growth conditions). Library preparation for direct RNA sequencing is shorter than that for direct cDNA sequencing. The sequence characteristics of the two methods were different, such as sequence yields, quality score of reads, read length distribution, and mapped on reference ability of reads. However, differential gene expression analyses derived from the two approaches are comparable. The unique feature of direct RNA sequencing is RNA modification; we found that the RNA modification at the 5' end of a transcript was underestimated due to the 3' bias behavior of the direct RNA sequencing. Our comprehensive evaluation from this work could help researchers make informed choices when selecting an appropriate long-read sequencing method for understanding gene functions, pathways, and detailed functional characterization.
Collapse
Affiliation(s)
- Thidathip Wongsurawat
- Division of Bioinformatics and Data Management for Research, Research Group and Research Network Division, Research Department, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Piroon Jenjaroenpun
- Division of Bioinformatics and Data Management for Research, Research Group and Research Network Division, Research Department, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Visanu Wanchai
- Department of Biomedical Informatics, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Intawat Nookaew
- Department of Biomedical Informatics, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| |
Collapse
|
13
|
Ugolini C, Mulroney L, Leger A, Castelli M, Criscuolo E, Williamson MK, Davidson AD, Almuqrin A, Giambruno R, Jain M, Frigè G, Olsen H, Tzertzinis G, Schildkraut I, Wulf MG, Corrêa IR, Ettwiller L, Clementi N, Clementi M, Mancini N, Birney E, Akeson M, Nicassio F, Matthews D, Leonardi T. Nanopore ReCappable sequencing maps SARS-CoV-2 5' capping sites and provides new insights into the structure of sgRNAs. Nucleic Acids Res 2022; 50:3475-3489. [PMID: 35244721 PMCID: PMC8989550 DOI: 10.1093/nar/gkac144] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 02/05/2022] [Accepted: 02/16/2022] [Indexed: 01/09/2023] Open
Abstract
The SARS-CoV-2 virus has a complex transcriptome characterised by multiple, nested subgenomic RNAsused to express structural and accessory proteins. Long-read sequencing technologies such as nanopore direct RNA sequencing can recover full-length transcripts, greatly simplifying the assembly of structurally complex RNAs. However, these techniques do not detect the 5' cap, thus preventing reliable identification and quantification of full-length, coding transcript models. Here we used Nanopore ReCappable Sequencing (NRCeq), a new technique that can identify capped full-length RNAs, to assemble a complete annotation of SARS-CoV-2 sgRNAs and annotate the location of capping sites across the viral genome. We obtained robust estimates of sgRNA expression across cell lines and viral isolates and identified novel canonical and non-canonical sgRNAs, including one that uses a previously un-annotated leader-to-body junction site. The data generated in this work constitute a useful resource for the scientific community and provide important insights into the mechanisms that regulate the transcription of SARS-CoV-2 sgRNAs.
Collapse
Affiliation(s)
- Camilla Ugolini
- Center for Genomic Science of IIT@SEMM, Fondazione Istituto Italiano di Tecnologia, 20139 Milano, Italy
| | - Logan Mulroney
- Center for Genomic Science of IIT@SEMM, Fondazione Istituto Italiano di Tecnologia, 20139 Milano, Italy
- European Molecular Biology Laboratory, European Bioinformatics Institute, Hinxton, UK
- Biomolecular Engineering Department, UC Santa Cruz, CA 95064, USA
| | - Adrien Leger
- European Molecular Biology Laboratory, European Bioinformatics Institute, Hinxton, UK
| | - Matteo Castelli
- Laboratory of Microbiology and Virology, Vita-Salute San Raffaele University; via Olgettina 58, 20132 Milan, Italy
| | - Elena Criscuolo
- Laboratory of Microbiology and Virology, Vita-Salute San Raffaele University; via Olgettina 58, 20132 Milan, Italy
| | - Maia Kavanagh Williamson
- School of Cellular and Molecular Medicine, Faculty of Life Sciences, University Walk, University of Bristol, Bristol BS8 1TD, UK
| | - Andrew D Davidson
- School of Cellular and Molecular Medicine, Faculty of Life Sciences, University Walk, University of Bristol, Bristol BS8 1TD, UK
| | - Abdulaziz Almuqrin
- School of Cellular and Molecular Medicine, Faculty of Life Sciences, University Walk, University of Bristol, Bristol BS8 1TD, UK
- Department of Clinical Laboratory Sciences, King Saud University, Riyadh, Saudi Arabia
| | - Roberto Giambruno
- Center for Genomic Science of IIT@SEMM, Fondazione Istituto Italiano di Tecnologia, 20139 Milano, Italy
| | - Miten Jain
- Biomolecular Engineering Department, UC Santa Cruz, CA 95064, USA
| | - Gianmaria Frigè
- Department of Experimental Oncology, IEO European Institute of Oncology IRCCS, 20139 Milano, Italy
| | - Hugh Olsen
- Biomolecular Engineering Department, UC Santa Cruz, CA 95064, USA
| | | | | | | | | | | | - Nicola Clementi
- Laboratory of Microbiology and Virology, Vita-Salute San Raffaele University; via Olgettina 58, 20132 Milan, Italy
- Laboratory of Medical Microbiology and Virology, IRCCS San Raffaele Scientific Institute; via Olgettina 60, 20132 Milan, Italy
| | - Massimo Clementi
- Laboratory of Microbiology and Virology, Vita-Salute San Raffaele University; via Olgettina 58, 20132 Milan, Italy
- Laboratory of Medical Microbiology and Virology, IRCCS San Raffaele Scientific Institute; via Olgettina 60, 20132 Milan, Italy
| | - Nicasio Mancini
- Laboratory of Microbiology and Virology, Vita-Salute San Raffaele University; via Olgettina 58, 20132 Milan, Italy
- Laboratory of Medical Microbiology and Virology, IRCCS San Raffaele Scientific Institute; via Olgettina 60, 20132 Milan, Italy
| | - Ewan Birney
- European Molecular Biology Laboratory, European Bioinformatics Institute, Hinxton, UK
| | - Mark Akeson
- Biomolecular Engineering Department, UC Santa Cruz, CA 95064, USA
| | - Francesco Nicassio
- Center for Genomic Science of IIT@SEMM, Fondazione Istituto Italiano di Tecnologia, 20139 Milano, Italy
| | - David A Matthews
- School of Cellular and Molecular Medicine, Faculty of Life Sciences, University Walk, University of Bristol, Bristol BS8 1TD, UK
| | - Tommaso Leonardi
- Center for Genomic Science of IIT@SEMM, Fondazione Istituto Italiano di Tecnologia, 20139 Milano, Italy
| |
Collapse
|
14
|
Wang H, Jiang F, Liu X, Liu Q, Fu Y, Li R, Hou L, Zhang J, He J, Kang L. Piwi/piRNAs control food intake by promoting neuropeptide F expression in locusts. EMBO Rep 2022; 23:e50851. [PMID: 34985794 PMCID: PMC8892266 DOI: 10.15252/embr.202050851] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Revised: 12/08/2021] [Accepted: 12/16/2021] [Indexed: 11/18/2022] Open
Abstract
Animal feeding, which directly affects growth and metabolism, is an important physiological process. However, the contribution of PIWI proteins and PIWI‐interacting RNAs (piRNAs) to the regulatory mechanism of animal feeding is unknown. Here, we report a novel function of Piwi and piRNAs in regulating food intake in locusts. Our study shows that the locust can serve as a representative species for determining PIWI function in insects. Knockdown of Piwi1 expression suppresses anabolic processes and reduces food consumption and body weight. The reduction in food intake by knockdown of Piwi1 expression results from decreased expression of neuropeptide NPF1 in a piRNA‐dependent manner. Mechanistically, intronic piRNAs might enhance RNA splicing of NPF1 by preventing hairpin formation at the branch point sites. These results suggest a novel nuclear PIWI/piRNA‐mediated mechanism that controls food intake in the locust nervous system.
Collapse
Affiliation(s)
- Huimin Wang
- Beijing Institutes of Life Science Chinese Academy of Sciences Beijing China
- CAS Center for Excellence in Biotic Interactions University of Chinese Academy of Sciences Beijing China
| | - Feng Jiang
- Beijing Institutes of Life Science Chinese Academy of Sciences Beijing China
- CAS Center for Excellence in Biotic Interactions University of Chinese Academy of Sciences Beijing China
| | - Xiang Liu
- State Key Laboratory of Integrated Management of Pest Insects and Rodents Institute of Zoology Chinese Academy of Sciences Beijing China
| | - Qing Liu
- State Key Laboratory of Integrated Management of Pest Insects and Rodents Institute of Zoology Chinese Academy of Sciences Beijing China
- Sino‐Danish College University of Chinese Academy of Sciences Beijing China
| | - Yunyun Fu
- College of Life Science Hebei University Baoding China
| | - Ran Li
- Beijing Institutes of Life Science Chinese Academy of Sciences Beijing China
| | - Li Hou
- State Key Laboratory of Integrated Management of Pest Insects and Rodents Institute of Zoology Chinese Academy of Sciences Beijing China
| | - Jie Zhang
- Beijing Institutes of Life Science Chinese Academy of Sciences Beijing China
| | - Jing He
- State Key Laboratory of Integrated Management of Pest Insects and Rodents Institute of Zoology Chinese Academy of Sciences Beijing China
| | - Le Kang
- Beijing Institutes of Life Science Chinese Academy of Sciences Beijing China
- CAS Center for Excellence in Biotic Interactions University of Chinese Academy of Sciences Beijing China
- State Key Laboratory of Integrated Management of Pest Insects and Rodents Institute of Zoology Chinese Academy of Sciences Beijing China
- College of Life Science Hebei University Baoding China
| |
Collapse
|
15
|
Mulroney L, Wulf MG, Schildkraut I, Tzertzinis G, Buswell J, Jain M, Olsen H, Diekhans M, Corrêa IR, Akeson M, Ettwiller L. Identification of high-confidence human poly(A) RNA isoform scaffolds using nanopore sequencing. RNA (NEW YORK, N.Y.) 2022; 28:162-176. [PMID: 34728536 PMCID: PMC8906549 DOI: 10.1261/rna.078703.121] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 10/13/2021] [Indexed: 06/13/2023]
Abstract
Nanopore sequencing devices read individual RNA strands directly. This facilitates identification of exon linkages and nucleotide modifications; however, using conventional direct RNA nanopore sequencing, the 5' and 3' ends of poly(A) RNA cannot be identified unambiguously. This is due in part to RNA degradation in vivo and in vitro that can obscure transcription start and end sites. In this study, we aimed to identify individual full-length human RNA isoforms among ∼4 million nanopore poly(A)-selected RNA reads. First, to identify RNA strands bearing 5' m7G caps, we exchanged the biological cap for a modified cap attached to a 45-nt oligomer. This oligomer adaptation method improved 5' end sequencing and ensured correct identification of the 5' m7G capped ends. Second, among these 5'-capped nanopore reads, we screened for features consistent with a 3' polyadenylation site. Combining these two steps, we identified 294,107 individual high-confidence full-length RNA scaffolds from human GM12878 cells, most of which (257,721) aligned to protein-coding genes. Of these, 4876 scaffolds indicated unannotated isoforms that were often internal to longer, previously identified RNA isoforms. Orthogonal data for m7G caps and open chromatin, such as CAGE and DNase-HS seq, confirmed the validity of these high-confidence RNA scaffolds.
Collapse
Affiliation(s)
- Logan Mulroney
- Biomolecular Engineering Department, UC Santa Cruz, California 95064, USA
| | | | | | | | - John Buswell
- New England Biolabs, Ipswich, Massachusetts 01938, USA
| | - Miten Jain
- Biomolecular Engineering Department, UC Santa Cruz, California 95064, USA
| | - Hugh Olsen
- Biomolecular Engineering Department, UC Santa Cruz, California 95064, USA
| | - Mark Diekhans
- Genomics Institute, UC Santa Cruz, California 95064, USA
| | - Ivan R Corrêa
- New England Biolabs, Ipswich, Massachusetts 01938, USA
| | - Mark Akeson
- Biomolecular Engineering Department, UC Santa Cruz, California 95064, USA
| | | |
Collapse
|
16
|
Nanopore sequencing technology, bioinformatics and applications. Nat Biotechnol 2021; 39:1348-1365. [PMID: 34750572 PMCID: PMC8988251 DOI: 10.1038/s41587-021-01108-x] [Citation(s) in RCA: 476] [Impact Index Per Article: 158.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 09/22/2021] [Indexed: 12/13/2022]
Abstract
Rapid advances in nanopore technologies for sequencing single long DNA and RNA molecules have led to substantial improvements in accuracy, read length and throughput. These breakthroughs have required extensive development of experimental and bioinformatics methods to fully exploit nanopore long reads for investigations of genomes, transcriptomes, epigenomes and epitranscriptomes. Nanopore sequencing is being applied in genome assembly, full-length transcript detection and base modification detection and in more specialized areas, such as rapid clinical diagnoses and outbreak surveillance. Many opportunities remain for improving data quality and analytical approaches through the development of new nanopores, base-calling methods and experimental protocols tailored to particular applications.
Collapse
|
17
|
Nicolau M, Picault N, Moissiard G. The Evolutionary Volte-Face of Transposable Elements: From Harmful Jumping Genes to Major Drivers of Genetic Innovation. Cells 2021; 10:cells10112952. [PMID: 34831175 PMCID: PMC8616336 DOI: 10.3390/cells10112952] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 10/20/2021] [Accepted: 10/20/2021] [Indexed: 12/25/2022] Open
Abstract
Transposable elements (TEs) are self-replicating DNA elements that constitute major fractions of eukaryote genomes. Their ability to transpose can modify the genome structure with potentially deleterious effects. To repress TE activity, host cells have developed numerous strategies, including epigenetic pathways, such as DNA methylation or histone modifications. Although TE neo-insertions are mostly deleterious or neutral, they can become advantageous for the host under specific circumstances. The phenomenon leading to the appropriation of TE-derived sequences by the host is known as TE exaptation or co-option. TE exaptation can be of different natures, through the production of coding or non-coding DNA sequences with ultimately an adaptive benefit for the host. In this review, we first give new insights into the silencing pathways controlling TE activity. We then discuss a model to explain how, under specific environmental conditions, TEs are unleashed, leading to a TE burst and neo-insertions, with potential benefits for the host. Finally, we review our current knowledge of coding and non-coding TE exaptation by providing several examples in various organisms and describing a method to identify TE co-option events.
Collapse
Affiliation(s)
- Melody Nicolau
- LGDP-UMR5096, CNRS, 66860 Perpignan, France; (M.N.); (N.P.)
- LGDP-UMR5096, Université de Perpignan Via Domitia, 66860 Perpignan, France
| | - Nathalie Picault
- LGDP-UMR5096, CNRS, 66860 Perpignan, France; (M.N.); (N.P.)
- LGDP-UMR5096, Université de Perpignan Via Domitia, 66860 Perpignan, France
| | - Guillaume Moissiard
- LGDP-UMR5096, CNRS, 66860 Perpignan, France; (M.N.); (N.P.)
- LGDP-UMR5096, Université de Perpignan Via Domitia, 66860 Perpignan, France
- Correspondence:
| |
Collapse
|
18
|
Dai Z, Ren J, Tong X, Hu H, Lu K, Dai F, Han MJ. The Landscapes of Full-Length Transcripts and Splice Isoforms as Well as Transposons Exonization in the Lepidopteran Model System, Bombyx mori. Front Genet 2021; 12:704162. [PMID: 34594358 PMCID: PMC8476886 DOI: 10.3389/fgene.2021.704162] [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: 05/01/2021] [Accepted: 09/01/2021] [Indexed: 11/13/2022] Open
Abstract
The domesticated silkworm, Bombyx mori, is an important model system for the order Lepidoptera. Currently, based on third-generation sequencing, the chromosome-level genome of Bombyx mori has been released. However, its transcripts were mainly assembled by using short reads of second-generation sequencing and expressed sequence tags which cannot explain the transcript profile accurately. Here, we used PacBio Iso-Seq technology to investigate the transcripts from 45 developmental stages of Bombyx mori. We obtained 25,970 non-redundant high-quality consensus isoforms capturing ∼60% of previous reported RNAs, 15,431 (∼47%) novel transcripts, and identified 7,253 long non-coding RNA (lncRNA) with a large proportion of novel lncRNA (∼56%). In addition, we found that transposable elements (TEs) exonization account for 11,671 (∼45%) transcripts including 5,980 protein-coding transcripts (∼32%) and 5,691 lncRNAs (∼79%). Overall, our results expand the silkworm transcripts and have general implications to understand the interaction between TEs and their host genes. These transcripts resource will promote functional studies of genes and lncRNAs as well as TEs in the silkworm.
Collapse
Affiliation(s)
- Zongrui Dai
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, College of Sericulture, Textile and Biomass Science, Southwest University, Chongqing, China.,WESTA College, Southwest University, Chongqing, China
| | - Jianyu Ren
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, College of Sericulture, Textile and Biomass Science, Southwest University, Chongqing, China
| | - Xiaoling Tong
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, College of Sericulture, Textile and Biomass Science, Southwest University, Chongqing, China
| | - Hai Hu
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, College of Sericulture, Textile and Biomass Science, Southwest University, Chongqing, China
| | - Kunpeng Lu
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, College of Sericulture, Textile and Biomass Science, Southwest University, Chongqing, China
| | - Fangyin Dai
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, College of Sericulture, Textile and Biomass Science, Southwest University, Chongqing, China
| | - Min-Jin Han
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, College of Sericulture, Textile and Biomass Science, Southwest University, Chongqing, China
| |
Collapse
|
19
|
Ibrahim F, Oppelt J, Maragkakis M, Mourelatos Z. TERA-Seq: true end-to-end sequencing of native RNA molecules for transcriptome characterization. Nucleic Acids Res 2021; 49:e115. [PMID: 34428294 PMCID: PMC8599856 DOI: 10.1093/nar/gkab713] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 07/31/2021] [Accepted: 08/18/2021] [Indexed: 11/14/2022] Open
Abstract
Direct sequencing of single, native RNA molecules through nanopores has a strong potential to transform research in all aspects of RNA biology and clinical diagnostics. The existing platform from Oxford Nanopore Technologies is unable to sequence the very 5′ ends of RNAs and is limited to polyadenylated molecules. Here, we develop True End-to-end RNA Sequencing (TERA-Seq), a platform that addresses these limitations, permitting more thorough transcriptome characterization. TERA-Seq describes both poly- and non-polyadenylated RNA molecules and accurately identifies their native 5′ and 3′ ends by ligating uniquely designed adapters that are sequenced along with the transcript. We find that capped, full-length mRNAs in human cells show marked variation of poly(A) tail lengths at the single molecule level. We report prevalent capping downstream of canonical transcriptional start sites in otherwise fully spliced and polyadenylated molecules. We reveal RNA processing and decay at single molecule level and find that mRNAs decay cotranslationally, often from their 5′ ends, while frequently retaining poly(A) tails. TERA-Seq will prove useful in many applications where true end-to-end direct sequencing of single, native RNA molecules and their isoforms is desirable.
Collapse
Affiliation(s)
- Fadia Ibrahim
- Department of Pathology and Laboratory Medicine, Division of Neuropathology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Department of Biochemistry and Molecular Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Jan Oppelt
- Department of Pathology and Laboratory Medicine, Division of Neuropathology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Manolis Maragkakis
- Laboratory of Genetics and Genomics, National Institute on Aging, Intramural Research Program, National Institutes of Health, Baltimore, MD 21224, USA
| | - Zissimos Mourelatos
- Department of Pathology and Laboratory Medicine, Division of Neuropathology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| |
Collapse
|
20
|
Tombácz D, Moldován N, Torma G, Nagy T, Hornyák Á, Csabai Z, Gulyás G, Boldogkői M, Jefferson VA, Zádori Z, Meyer F, Boldogkői Z. Dynamic Transcriptome Sequencing of Bovine Alphaherpesvirus Type 1 and Host Cells Carried Out by a Multi-Technique Approach. Front Genet 2021; 12:619056. [PMID: 33897757 PMCID: PMC8059770 DOI: 10.3389/fgene.2021.619056] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 03/16/2021] [Indexed: 12/12/2022] Open
Affiliation(s)
- Dóra Tombácz
- Department of Medical Biology, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Norbert Moldován
- Department of Medical Biology, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Gábor Torma
- Department of Medical Biology, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Tibor Nagy
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Ákos Hornyák
- Institute for Veterinary Medical Research, Centre for Agricultural Research, Budapest, Hungary
| | - Zsolt Csabai
- Department of Medical Biology, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Gábor Gulyás
- Department of Medical Biology, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Miklós Boldogkői
- Department of Medical Biology, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Victoria A Jefferson
- Department of Biochemistry & Molecular Biology, Entomology & Plant Pathology, Mississippi State University, Starkville, MS, United States
| | - Zoltán Zádori
- Institute for Veterinary Medical Research, Centre for Agricultural Research, Budapest, Hungary
| | - Florencia Meyer
- Department of Biochemistry & Molecular Biology, Entomology & Plant Pathology, Mississippi State University, Starkville, MS, United States
| | - Zsolt Boldogkői
- Department of Medical Biology, Faculty of Medicine, University of Szeged, Szeged, Hungary
| |
Collapse
|
21
|
Liu Q, Jiang F, Zhang J, Li X, Kang L. Transcription initiation of distant core promoters in a large-sized genome of an insect. BMC Biol 2021; 19:62. [PMID: 33785021 PMCID: PMC8011201 DOI: 10.1186/s12915-021-01004-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2020] [Accepted: 03/16/2021] [Indexed: 12/30/2022] Open
Abstract
Background Core promoters have a substantial influence on various steps of transcription, including initiation, elongation, termination, polyadenylation, and finally, translation. The characterization of core promoters is crucial for exploring the regulatory code of transcription initiation. However, the current understanding of insect core promoters is focused on those of Diptera (especially Drosophila) species with small genome sizes. Results Here, we present an analysis of the transcription start sites (TSSs) in the migratory locust, Locusta migratoria, which has a genome size of 6.5 Gb. The genomic differences, including lower precision of transcription initiation and fewer constraints on the distance from transcription factor binding sites or regulatory elements to TSSs, were revealed in locusts compared with Drosophila insects. Furthermore, we found a distinct bimodal log distribution of the distances from the start codons to the core promoters of locust genes. We found stricter constraints on the exon length of mRNA leaders and widespread expression activity of the distant core promoters in locusts compared with fruit flies. We further compared core promoters in seven arthropod species across a broad range of genome sizes to reinforce our results on the emergence of distant core promoters in large-sized genomes. Conclusions In summary, our results provide novel insights into the effects of genome size expansion on distant transcription initiation. Supplementary Information The online version contains supplementary material available at 10.1186/s12915-021-01004-5.
Collapse
Affiliation(s)
- Qing Liu
- Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing, China.,Sino-Danish College, University of Chinese Academy of Sciences, Beijing, China.,Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Feng Jiang
- Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing, China.,CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China
| | - Jie Zhang
- Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing, China
| | - Xiao Li
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Le Kang
- Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing, China. .,CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China. .,State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.
| |
Collapse
|
22
|
Time-course profiling of bovine alphaherpesvirus 1.1 transcriptome using multiplatform sequencing. Sci Rep 2020; 10:20496. [PMID: 33235226 PMCID: PMC7686369 DOI: 10.1038/s41598-020-77520-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Accepted: 11/04/2020] [Indexed: 12/11/2022] Open
Abstract
Long-read sequencing (LRS) has become a standard approach for transcriptome analysis in recent years. Bovine alphaherpesvirus 1 (BoHV-1) is an important pathogen of cattle worldwide. This study reports the profiling of the dynamic lytic transcriptome of BoHV-1 using two long-read sequencing (LRS) techniques, the Oxford Nanopore Technologies MinION, and the LoopSeq synthetic LRS methods, using multiple library preparation protocols. In this work, we annotated viral mRNAs and non-coding transcripts, and a large number of transcript isoforms, including transcription start and end sites, as well as splice variants of BoHV-1. Our analysis demonstrated an extremely complex pattern of transcriptional overlaps.
Collapse
|
23
|
Villagra C, Frías-Lasserre D. Epigenetic Molecular Mechanisms in Insects. NEOTROPICAL ENTOMOLOGY 2020; 49:615-642. [PMID: 32514997 DOI: 10.1007/s13744-020-00777-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 04/06/2020] [Indexed: 06/11/2023]
Abstract
Insects are the largest animal group on Earth both in biomass and diversity. Their outstanding success has inspired genetics and developmental research, allowing the discovery of dynamic process explaining extreme phenotypic plasticity and canalization. Epigenetic molecular mechanisms (EMMs) are vital for several housekeeping functions in multicellular organisms, regulating developmental, ontogenetic trajectories and environmental adaptations. In Insecta, EMMs are involved in the development of extreme phenotypic divergences such as polyphenisms and eusocial castes. Here, we review the history of this research field and how the main EMMs found in insects help to understand their biological processes and diversity. EMMs in insects confer them rapid response capacity allowing insect either to change with plastic divergence or to keep constant when facing different stressors or stimuli. EMMs function both at intra as well as transgenerational scales, playing important roles in insect ecology and evolution. We discuss on how EMMs pervasive influences in Insecta require not only the control of gene expression but also the dynamic interplay of EMMs with further regulatory levels, including genetic, physiological, behavioral, and environmental among others, as was earlier proposed by the Probabilistic Epigenesis model and Developmental System Theory.
Collapse
Affiliation(s)
- C Villagra
- Instituto de Entomología, Univ Metropolitana de Ciencias de la Educación, Santiago, Chile.
| | - D Frías-Lasserre
- Instituto de Entomología, Univ Metropolitana de Ciencias de la Educación, Santiago, Chile
| |
Collapse
|
24
|
Shao X, Zhang H, Yang Z, Zhong H, Xia Y, Cai Z. NAD tagSeq for transcriptome-wide identification and characterization of NAD +-capped RNAs. Nat Protoc 2020; 15:2813-2836. [PMID: 32747820 DOI: 10.1038/s41596-020-0363-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Accepted: 04/29/2020] [Indexed: 11/09/2022]
Abstract
Several noncanonical initial nucleotides (NCINs) have been found to cap RNAs and possibly regulate RNA stability, transcription and translation. NAD+ is one of the NCINs that has recently been discovered to cap RNAs in a wide range of species. Identification of the NAD+-capped RNAs (NAD-RNAs) could help to unveil the cap-mediated regulation mechanisms. We previously reported a method termed NAD tagSeq for genome-wide analysis of NAD-RNAs. NAD tagSeq is based on the previously published NAD captureSeq protocol, which applies an enzymatic reaction and a click chemistry reaction to label NAD-RNAs with biotin followed by enrichment with streptavidin resin and identification by RNA sequencing. In the current NAD tagSeq method, NAD-RNAs are labeled with a synthetic RNA tag and identified by direct RNA sequencing based on Oxford Nanopore technology. Compared to NAD captureSeq, NAD tagSeq provides a simpler procedure for direct sequencing of NAD-RNAs and noncapped RNAs and affords information on the whole sequence organization of NAD-RNAs and the ratio of NAD-RNAs to total transcripts. Furthermore, NAD-RNAs can be enriched by hybridizing a complementary DNA probe to the RNA tag, thus increasing the sequencing coverage of NAD-RNAs. The strategy of tagging RNAs with a synthetic RNA tag and identifying them by direct RNA sequencing might be employed in analyzing other NCIN-capped RNAs. The experimental procedure of NAD tagSeq, including RNA extraction, RNA tagging and direct RNA sequencing, takes ~5 d, and initial data analysis can be completed within 2 d.
Collapse
Affiliation(s)
- Xiaojian Shao
- State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Hong Kong, China
| | - Hailei Zhang
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | - Zhu Yang
- State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Hong Kong, China
| | - Huan Zhong
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | - Yiji Xia
- State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Hong Kong, China. .,Department of Biology, Hong Kong Baptist University, Hong Kong, China. .,State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong, China.
| | - Zongwei Cai
- State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Hong Kong, China.
| |
Collapse
|
25
|
Lanciano S, Cristofari G. Measuring and interpreting transposable element expression. Nat Rev Genet 2020; 21:721-736. [PMID: 32576954 DOI: 10.1038/s41576-020-0251-y] [Citation(s) in RCA: 164] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/19/2020] [Indexed: 12/21/2022]
Abstract
Transposable elements (TEs) are insertional mutagens that contribute greatly to the plasticity of eukaryotic genomes, influencing the evolution and adaptation of species as well as physiology or disease in individuals. Measuring TE expression helps to understand not only when and where TE mobilization can occur but also how this process alters gene expression, chromatin accessibility or cellular signalling pathways. Although genome-wide gene expression assays such as RNA sequencing include transposon-derived transcripts, most computational analytical tools discard or misinterpret TE-derived reads. Emerging approaches are improving the identification of expressed TE loci and helping to discriminate TE transcripts that permit TE mobilization from chimeric gene-TE transcripts or pervasive transcription. Here we review the main challenges associated with the detection of TE expression, including mappability, insertional and internal sequence polymorphisms, and the diversity of the TE transcriptional landscape, as well as the different experimental and computational strategies to solve them.
Collapse
|
26
|
Furlan M, Tanaka I, Leonardi T, de Pretis S, Pelizzola M. Direct RNA Sequencing for the Study of Synthesis, Processing, and Degradation of Modified Transcripts. Front Genet 2020; 11:394. [PMID: 32425981 PMCID: PMC7212349 DOI: 10.3389/fgene.2020.00394] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 03/30/2020] [Indexed: 01/24/2023] Open
Abstract
It has been known for a few decades that transcripts can be marked by dozens of different modifications. Yet, we are just at the beginning of charting these marks and understanding their functional impact. High-quality methods were developed for the profiling of some of these marks, and approaches to finely study their impact on specific phases of the RNA life-cycle are available, including RNA metabolic labeling. Thanks to these improvements, the most abundant marks, including N6-methyladenosine, are emerging as important determinants of the fate of marked RNAs. However, we still lack approaches to directly study how the set of marks for a given RNA molecule shape its fate. In this perspective, we first review current leading approaches in the field. Then, we propose an experimental and computational setup, based on direct RNA sequencing and mathematical modeling, to decipher the functional consequences of RNA modifications on the fate of individual RNA molecules and isoforms.
Collapse
Affiliation(s)
- Mattia Furlan
- Center for Genomic Science, Istituto Italiano di Tecnologia, Milan, Italy
- Department of Physics, National Institute of Nuclear Physics, University of Turin, Turin, Italy
| | - Iris Tanaka
- Center for Genomic Science, Istituto Italiano di Tecnologia, Milan, Italy
| | - Tommaso Leonardi
- Center for Genomic Science, Istituto Italiano di Tecnologia, Milan, Italy
| | - Stefano de Pretis
- Center for Genomic Science, Istituto Italiano di Tecnologia, Milan, Italy
| | - Mattia Pelizzola
- Center for Genomic Science, Istituto Italiano di Tecnologia, Milan, Italy
| |
Collapse
|
27
|
Parker MT, Knop K, Sherwood AV, Schurch NJ, Mackinnon K, Gould PD, Hall AJW, Barton GJ, Simpson GG. Nanopore direct RNA sequencing maps the complexity of Arabidopsis mRNA processing and m 6A modification. eLife 2020; 9:e49658. [PMID: 31931956 PMCID: PMC6959997 DOI: 10.7554/elife.49658] [Citation(s) in RCA: 260] [Impact Index Per Article: 65.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Accepted: 12/05/2019] [Indexed: 12/18/2022] Open
Abstract
Understanding genome organization and gene regulation requires insight into RNA transcription, processing and modification. We adapted nanopore direct RNA sequencing to examine RNA from a wild-type accession of the model plant Arabidopsis thaliana and a mutant defective in mRNA methylation (m6A). Here we show that m6A can be mapped in full-length mRNAs transcriptome-wide and reveal the combinatorial diversity of cap-associated transcription start sites, splicing events, poly(A) site choice and poly(A) tail length. Loss of m6A from 3' untranslated regions is associated with decreased relative transcript abundance and defective RNA 3' end formation. A functional consequence of disrupted m6A is a lengthening of the circadian period. We conclude that nanopore direct RNA sequencing can reveal the complexity of mRNA processing and modification in full-length single molecule reads. These findings can refine Arabidopsis genome annotation. Further, applying this approach to less well-studied species could transform our understanding of what their genomes encode.
Collapse
MESH Headings
- Adenosine/analogs & derivatives
- Adenosine/metabolism
- Arabidopsis/genetics
- Arabidopsis/metabolism
- Gene Expression Profiling
- Methylation
- Nanopores
- Poly A/genetics
- Poly A/metabolism
- RNA Caps
- RNA Processing, Post-Transcriptional
- RNA Splicing
- RNA, Messenger/chemistry
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- RNA, Plant/chemistry
- RNA, Plant/genetics
- RNA, Plant/metabolism
- RNA, Untranslated/chemistry
- RNA, Untranslated/genetics
- Sequence Analysis, RNA
Collapse
Affiliation(s)
| | - Katarzyna Knop
- School of Life SciencesUniversity of DundeeDundeeUnited Kingdom
| | - Anna V Sherwood
- School of Life SciencesUniversity of DundeeDundeeUnited Kingdom
| | | | | | - Peter D Gould
- Institute of Integrative BiologyUniversity of LiverpoolLiverpoolUnited Kingdom
| | | | | | - Gordon G Simpson
- School of Life SciencesUniversity of DundeeDundeeUnited Kingdom
- James Hutton InstituteInvergowrieUnited Kingdom
| |
Collapse
|
28
|
Tombácz D, Moldován N, Balázs Z, Gulyás G, Csabai Z, Boldogkői M, Snyder M, Boldogkői Z. Multiple Long-Read Sequencing Survey of Herpes Simplex Virus Dynamic Transcriptome. Front Genet 2019; 10:834. [PMID: 31608102 PMCID: PMC6769088 DOI: 10.3389/fgene.2019.00834] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 08/13/2019] [Indexed: 12/12/2022] Open
Abstract
Long-read sequencing (LRS) has become increasingly important in RNA research due to its strength in resolving complex transcriptomic architectures. In this regard, currently two LRS platforms have demonstrated adequate performance: the Single Molecule Real-Time Sequencing by Pacific Biosciences (PacBio) and the nanopore sequencing by Oxford Nanopore Technologies (ONT). Even though these techniques produce lower coverage and are more error prone than short-read sequencing, they continue to be more successful in identifying polycistronic RNAs, transcript isoforms including splice and transcript end variants, as well as transcript overlaps. Recent reports have successfully applied LRS for the investigation of the transcriptome of viruses belonging to various families. These studies have substantially increased the number of previously known viral RNA molecules. In this work, we used the Sequel and MinION technique from PacBio and ONT, respectively, to characterize the lytic transcriptome of the herpes simplex virus type 1 (HSV-1). In most samples, we analyzed the poly(A) fraction of the transcriptome, but we also performed random oligonucleotide-based sequencing. Besides cDNA sequencing, we also carried out native RNA sequencing. Our investigations identified more than 2,300 previously undetected transcripts, including coding, and non-coding RNAs, multi-splice transcripts, as well as polycistronic and complex transcripts. Furthermore, we found previously unsubstantiated transcriptional start sites, polyadenylation sites, and splice sites. A large number of novel transcriptional overlaps were also detected. Random-primed sequencing revealed that each convergent gene pair produces non-polyadenylated read-through RNAs overlapping the partner genes. Furthermore, we identified novel replication-associated transcripts overlapping the HSV-1 replication origins, and novel LAT variants with very long 5' regions, which are co-terminal with the LAT-0.7kb transcript. Overall, our results demonstrated that the HSV-1 transcripts form an extremely complex pattern of overlaps, and that entire viral genome is transcriptionally active. In most viral genes, if not in all, both DNA strands are expressed.
Collapse
Affiliation(s)
- Dóra Tombácz
- Department of Medical Biology, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Norbert Moldován
- Department of Medical Biology, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Zsolt Balázs
- Department of Medical Biology, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Gábor Gulyás
- Department of Medical Biology, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Zsolt Csabai
- Department of Medical Biology, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Miklós Boldogkői
- Department of Medical Biology, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Michael Snyder
- Department of Genetics, School of Medicine, Stanford University, Stanford, CA, United States
| | - Zsolt Boldogkői
- Department of Medical Biology, Faculty of Medicine, University of Szeged, Szeged, Hungary
| |
Collapse
|