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Li L, Liu P, Sun L, Bin Zhou, Fei J. PiggyBac transposon-based polyadenylation-signal trap for genome-wide mutagenesis in mice. Sci Rep 2016; 6:27788. [PMID: 27292714 PMCID: PMC4904408 DOI: 10.1038/srep27788] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 05/23/2016] [Indexed: 12/12/2022] Open
Abstract
We designed a new type of polyadenylation-signal (PAS) trap vector system in living mice, the piggyBac (PB) (PAS-trapping (EGFP)) gene trapping vector, which takes advantage of the efficient transposition ability of PB and efficient gene trap and insertional mutagenesis of PAS-trapping. The reporter gene of PB(PAS-trapping (EGFP)) is an EGFP gene with its own promoter, but lacking a poly(A) signal. Transgenic mouse lines carrying PB(PAS-trapping (EGFP)) and protamine 1 (Prm1) promoter-driven PB transposase transgenes (Prm1-PBase) were generated by microinjection. Male mice doubly positive for PB(PAS-trapping (EGFP)) and Prm1-PBase were crossed with WT females, generating offspring with various insertion mutations. We found that 44.8% (26/58) of pups were transposon-positive progenies. New transposon integrations comprised 26.9% (7/26) of the transposon-positive progenies. We found that 100% (5/5) of the EGFP fluorescence-positive mice had new trap insertions mediated by a PB transposon in transcriptional units. The direction of the EGFP gene in the vector was consistent with the direction of the endogenous gene reading frame. Furthermore, mice that were EGFP-PCR positive, but EGFP fluorescent negative, did not show successful gene trapping. Thus, the novel PB(PAS-trapping (EGFP)) system is an efficient genome-wide gene-trap mutagenesis in mice.
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Affiliation(s)
- Limei Li
- Research Center for Translational Medicine, Shanghai East Hospital, Tongji University School of Medicine, Shanghai 200120, China
- Department of vascular surgery, Shanghai East Hospital, Tongji University School of Medicine, Shanghai 200120, China
- Key Laboratory of Arrhythmias of the Ministry of Education of China, East Hospital, Tongji University School of Medicine, Shanghai, China
| | - Peng Liu
- Research Center for Translational Medicine, Shanghai East Hospital, Tongji University School of Medicine, Shanghai 200120, China
- Department of Cardiology, East Hospital, Tongji University School of Medicine, Shanghai, China
| | - Liangliang Sun
- Department of Endocrinology, Changzheng Hospital, Second Military Medical University, Shanghai, 200003, PR China
| | - Bin Zhou
- Department of vascular surgery, Shanghai East Hospital, Tongji University School of Medicine, Shanghai 200120, China
| | - Jian Fei
- Research Center for Translational Medicine, Shanghai East Hospital, Tongji University School of Medicine, Shanghai 200120, China
- Metastasis research institute, Shanghai East Hospital, Tongji University School of Medicine, Shanghai 200120, China
- School of Life Science and Technology, Tongji University, Shanghai, China
- Shanghai Research Center for Model Organisms, Shanghai, 201203, China
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Song G, Cui Z. Novel strategies for gene trapping and insertional mutagenesis mediated by Sleeping Beauty transposon. Mob Genet Elements 2013; 3:e26499. [PMID: 24251071 DOI: 10.4161/mge.26499] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Revised: 09/10/2013] [Accepted: 09/15/2013] [Indexed: 12/29/2022] Open
Abstract
Gene and poly(A) trappings are high-throughput approaches to capture and interrupt the expression of endogenous genes within a target genome. Although a number of trapping vectors have been developed for investigation of gene functions in cells and vertebrate models, there is still room for the improvement of their efficiency and sensitivity. Recently, two novel trapping vectors mediated by Sleeping Beauty (SB) transposon have been generated by the combination of three functional cassettes that are required for finding endogenous genes, disrupting the expression of trapped genes, and inducing the excision of integrated traps from their original insertion sites and then inserting into another gene. In addition, several other strategies are utilized to improve the activities of two trapping vectors. First, activities of all components were examined in vitro before the generation of two vectors. Second, the inducible promoter from the tilapia Hsp70 gene was used to drive the expression of SB gene, which can mediate the excision of integrated transposons upon induction at 37 °C. Third, the Cre/LoxP system was introduced to delete the SB expression cassette for stabilization of gene interruption and bio-safety. Fourth, three stop codons in different reading frames were introduced downstream of a strong splice acceptor (SA) in the gene trapping vector to effectively terminate the translation of trapped endogenous genes. Fifth, the strong splicing donor (SD) and AU-rich RNA-destabilizing element exhibited no obvious insertion bias and markedly reduced SD read-through events, and the combination of an enhanced SA, a poly(A) signal and a transcript terminator in the poly(A) trapping vector efficiently disrupted the transcription of trapped genes. Thus, these two trapping vectors are alternative and effective tools for large-scale identification and disruption of endogenous genes in vertebrate cells and animals.
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Affiliation(s)
- Guili Song
- Institute of Hydrobiology; Chinese Academy of Sciences; Wuhan, P.R. China
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Sharma N, Hollensen AK, Bak RO, Staunstrup NH, Schrøder LD, Mikkelsen JG. The impact of cHS4 insulators on DNA transposon vector mobilization and silencing in retinal pigment epithelium cells. PLoS One 2012; 7:e48421. [PMID: 23110238 PMCID: PMC3482222 DOI: 10.1371/journal.pone.0048421] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2012] [Accepted: 09/25/2012] [Indexed: 12/29/2022] Open
Abstract
DNA transposons have become important vectors for efficient non-viral integration of transgenes into genomic DNA. The Sleeping Beauty (SB), piggyBac (PB), and Tol2 transposable elements have distinct biological properties and currently represent the most promising transposon systems for animal transgenesis and gene therapy. A potential obstacle, however, for persistent function of integrating vectors is transcriptional repression of the element and its genetic cargo. In this study we analyze the insulating effect of the 1.2-kb 5'-HS4 chicken β-globin (cHS4) insulator element in the context of SB, PB, and Tol2 transposon vectors. By examining transgene expression from genomically inserted transposon vectors encoding a marker gene driven by a silencing-prone promoter, we detect variable levels of transcriptional silencing for the three transposon systems in retinal pigment epithelium cells. Notably, the PB system seems less vulnerable to silencing. Incorporation of cHS4 insulator sequences into the transposon vectors results in 2.2-fold and 1.5-fold increased transgene expression levels for insulated SB and PB vectors, respectively, but an improved persistency of expression was not obtained for insulated transgenes. Colony formation assays and quantitative excision assays unveil enhanced SB transposition efficiencies by the inclusion of the cHS4 element, resulting in a significant increase in the stable transfection rate for insulated SB transposon vectors in human cell lines. Our findings reveal a positive impact of cHS4 insulator inclusion for SB and PB vectors in terms of increased transgene expression levels and improved SB stable transfection rates, but also the lack of a long-term protective effect of the cHS4 insulator against progressive transgene silencing in retinal pigment epithelium cells.
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Affiliation(s)
- Nynne Sharma
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | | | - Rasmus O. Bak
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
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Sormacheva I, Smyshlyaev G, Mayorov V, Blinov A, Novikov A, Novikova O. Vertical Evolution and Horizontal Transfer of CR1 Non-LTR Retrotransposons and Tc1/mariner DNA Transposons in Lepidoptera Species. Mol Biol Evol 2012; 29:3685-702. [DOI: 10.1093/molbev/mss181] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
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Zhang Z, Saier MH. Transposon-mediated adaptive and directed mutations and their potential evolutionary benefits. J Mol Microbiol Biotechnol 2012; 21:59-70. [PMID: 22248543 DOI: 10.1159/000333108] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Transposons, mobile genetic elements that can hop from one chromosomal location to another, are known to be both beneficial and deleterious to the cell that bears them. Their value in accelerating evolutionary adaptation is well recognized. We herein summarize published research dealing with these elements and then move on to review our own research efforts which focus on a small transposon that can induce mutations under the control of host factors in a process that phenotypically and mechanistically conforms to the definition of 'directed mutation'. Directed mutations occur at higher frequencies when they are beneficial, being induced by the stress condition that they relieve. Here, we review evidence for transposon-mediated directed mutation in Escherichia coli. Deletion mutants in the crp gene can not grow on glycerol (Glp(-)); however, these cells mutate specifically to efficient glycerol utilization (Glp(+)) at rates that are greatly enhanced by the presence of glycerol or the loss of the glycerol repressor (GlpR). These rates are greatly depressed by glucose or by glpR overexpression. Of the four tandem GlpR-binding sites (O1-O4) in the control region of the glpFK operon, O4 (downstream) specifically controls glpFK expression while O1 (upstream) controls mutation rate. Mutation is due to insertion of the small transposon IS5 into a specific site just upstream of the glpFK promoter. Mutational control by the glycerol regulon repressor GlpR is independent of the selection and assay procedures, and IS5 insertion into other gene activation sites is unaffected by the presence of glycerol or the loss of GlpR. The results establish the principle of transposon-mediated directed mutation, identify a protein responsible for its regulation, and define essential aspects of the mechanism.
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Affiliation(s)
- Zhongge Zhang
- Division of Biological Sciences, Department of Molecular Biology, University of California at San Diego, La Jolla, CA, USA.
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Ménoret S, Tesson L, Remy S, Usal C, Iscache AL, Thynard R, Nguyen TH, Anegon I. Transgenesis and genome analysis, Nantes, France, June 6th 2011. Transgenic Res 2011. [PMCID: PMC7101805 DOI: 10.1007/s11248-011-9541-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Séverine Ménoret
- Platform Transgenic Rats Nantes IBiSA, Nantes, France
- CHU Nantes, Nantes, France
- Université de Nantes, Nantes, France
- CNRS, Nantes, France
| | - Laurent Tesson
- Platform Transgenic Rats Nantes IBiSA, Nantes, France
- CHU Nantes, Nantes, France
- Université de Nantes, Nantes, France
- INSERM UMR 643, 44093 Nantes, France
| | - Séverine Remy
- Platform Transgenic Rats Nantes IBiSA, Nantes, France
- CHU Nantes, Nantes, France
- Université de Nantes, Nantes, France
- INSERM UMR 643, 44093 Nantes, France
| | - Claire Usal
- Platform Transgenic Rats Nantes IBiSA, Nantes, France
- CHU Nantes, Nantes, France
- Université de Nantes, Nantes, France
- INSERM UMR 643, 44093 Nantes, France
| | - Anne-Laure Iscache
- Platform Transgenic Rats Nantes IBiSA, Nantes, France
- CHU Nantes, Nantes, France
- Université de Nantes, Nantes, France
- INSERM UMR 643, 44093 Nantes, France
| | - Reynald Thynard
- Platform Transgenic Rats Nantes IBiSA, Nantes, France
- CHU Nantes, Nantes, France
- Université de Nantes, Nantes, France
- INSERM UMR 643, 44093 Nantes, France
| | | | - Ignacio Anegon
- Platform Transgenic Rats Nantes IBiSA, Nantes, France
- CHU Nantes, Nantes, France
- Université de Nantes, Nantes, France
- CNRS, Nantes, France
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