1.Functional characterization of piggyBac-like elements from Nilaparvata lugens (Stål) (Hemiptera: Delphacidae).
Jun LYU ; Qin SU ; Jinhui LIU ; Lin CHEN ; Jiawei SUN ; Wenqing ZHANG
Journal of Zhejiang University. Science. B 2022;23(6):515-527
PiggyBac is a transposable DNA element originally discovered in the cabbage looper moth (Trichoplusia ni). The T. ni piggyBac transposon can introduce exogenous fragments into a genome, constructing a transgenic organism. Nevertheless, the comprehensive analysis of endogenous piggyBac-like elements (PLEs) is important before using piggyBac, because they may influence the genetic stability of transgenic lines. Herein, we conducted a genome-wide analysis of PLEs in the brown planthopper (BPH) Nilaparvata lugens (Stål) (Hemiptera: Delphacidae), and identified a total of 28 PLE sequences. All N. lugens piggyBac-like elements (NlPLEs) were present as multiple copies in the genome of BPH. Among the identified NlPLEs, NlPLE25 had the highest copy number and it was distributed on five chromosomes. The full length of NlPLE25 consisted of terminal inverted repeats and sub-terminal inverted repeats at both terminals, as well as a single open reading frame transposase encoding 546 amino acids. Furthermore, NlPLE25 transposase caused precise excision and transposition in cultured insect cells and also restored the original TTAA target sequence after excision. A cross-recognition between the NlPLE25 transposon and the piggyBac transposon was also revealed in this study. These findings provide useful information for the construction of transgenic insect lines.
Amino Acid Sequence
;
Animals
;
Animals, Genetically Modified
;
DNA Transposable Elements/genetics*
;
Hemiptera/genetics*
;
Transposases/genetics*
2.Recent advances in CRISPR-related transposable elements.
Shuqing NING ; Xinxin WU ; Yunzi LUO
Chinese Journal of Biotechnology 2022;38(12):4371-4384
A new wave of research has been inspired by the CRISPR-Cas system with respect to their application in genome editing. The CRISPR-Cas system can not only be applied in gene knockout and insertion, but also be used in base editing, transcriptional regulation and recombination of gene clusters. However, the low efficiency of homology-directed repair (HDR) limits its application. Unlike the CRISPR-Cas system, mobile genetic elements (MGE) can insert DNA fragments into cell chromosomes without the aid of HDR. Recently, it is reported that CRISPR-related transposable elements can guide targeted DNA insertion. Their transposition mechanisms and reprogramming abilities have brought novel opportunities to the development of this field. This review summarized the research progress and application development of natural CRISPR-related transposable elements in recent years, as well as the applications of fused dCas9-transposase. It proposed the application prospects and potential challenges of CRISPR-related transposable elements in the future, which provided a reference for the development direction of gene editing tools.
DNA Transposable Elements/genetics*
;
Gene Editing
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CRISPR-Cas Systems/genetics*
3.Insights into epigenetic patterns in mammalian early embryos.
Ruimin XU ; Chong LI ; Xiaoyu LIU ; Shaorong GAO
Protein & Cell 2021;12(1):7-28
Mammalian fertilization begins with the fusion of two specialized gametes, followed by major epigenetic remodeling leading to the formation of a totipotent embryo. During the development of the pre-implantation embryo, precise reprogramming progress is a prerequisite for avoiding developmental defects or embryonic lethality, but the underlying molecular mechanisms remain elusive. For the past few years, unprecedented breakthroughs have been made in mapping the regulatory network of dynamic epigenomes during mammalian early embryo development, taking advantage of multiple advances and innovations in low-input genome-wide chromatin analysis technologies. The aim of this review is to highlight the most recent progress in understanding the mechanisms of epigenetic remodeling during early embryogenesis in mammals, including DNA methylation, histone modifications, chromatin accessibility and 3D chromatin organization.
Animals
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Chromatin Assembly and Disassembly
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DNA Methylation
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DNA Transposable Elements
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Embryo, Mammalian
;
Embryonic Development/genetics*
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Epigenesis, Genetic
;
Epigenome
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Female
;
Fertilization/physiology*
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Gene Expression Regulation, Developmental
;
Histone Code
;
Histones/metabolism*
;
Male
;
Mice
;
Oocytes/metabolism*
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Spermatozoa/metabolism*
4.Construction of Tn5 transposon insertion mutants of Ralstonia solanacearum isolated from Pogostemon cablin.
Ya-Qin WANG ; Yu-Yao ZHANG ; Hong HE ; Zhuan LI ; Zhi-Cheng DENG ; Hua JIN ; Guang-Wei LI
China Journal of Chinese Materia Medica 2019;44(1):77-81
Ralstonia solanacearum strain PRS-84 used in this study was isolated from diseased Pogostemon cablin plants in our previous study.The competent cells of R.solanacearum strain PRS-84 were transformed by electroporation with Tn5 transposon and then were plated on TTC agar plates containing kanamycin to select for kanamycin-resistant colonies.The detection of kanamycin-resistant gene in kanamycin-resistant colonies was performed by PCR.Further,the flanking fragments of Tn5 transposon insertion site in the mutants were amplified by inverse PCR,and the flanking fragments were sequenced and analyzed.The results indicated that the kanamycin-resistant colonies were obtained in the transformation experiment of R.solanacearum strain PRS-84 by electroporation with Tn5 transposon.A specific band of approximately 700 bp was amplified by PCR from kanamycin-resistant colonies.The flanking sequences of Tn5 transposon insertion site in the transformants were obtained by inverse PCR.After sequencing and sequence analysis of Tn5 transposon insertion site in mutants,we preliminarily speculated that the Tn5 transposon inserted in the typ A gene,rec O gene and gid A gene in three mutants,respectively.A random mutagenesis system of R.solanacearum strain PRS-84 by electroporation with Tn5 transposon has been established,and the Tn5 insertion mutants have been obtained.This study might facilitate the creation of mutant library and the discovery of the virulence gene of R.solanacearum isolated from P.cablin.
DNA Transposable Elements
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Electroporation
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Genes, Bacterial
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Mutagenesis, Insertional
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Pogostemon
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microbiology
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Ralstonia solanacearum
;
genetics
;
Virulence
6.Comparison of MITE transposons mPing in different rice subspecies.
Ning ZHANG ; Yanan RUAN ; Shanshan WANG ; Yang LIU ; Chen ZHAO ; Jingjing WANG ; Kaixi WANG ; Yanli WANG ; Hongyan WANG
Chinese Journal of Biotechnology 2016;32(9):1264-1272
The mPing family is the first active MITE TE family identified in rice genome. In order to compare the compositions and distributions of mPing family in the genomes of two rice subspecies japonica (cv. Nipponbare) and indica (cv. 93-11), we initially estimated the copy numbers of mPing family in those two subspecies using Southern blot and then confirmed the results by searching homologous copies in each reference genome using Blastn program, which turned out to have 52 and 14 mPing copies in corresponding reference genome, respectively. All mPing members in Nipponbare genome belong to mPing-1, while there are 3 mPing-1 and 11 mPing-2 copies in 93-11 genome. By further investigating the 5-kb flanking sequences of those mPing copies, it was found that 23 and 3 protein-coding genes in Nipponbare and 93-11 genome are residing adjacent to those mPing copies respectively. These results establish the preliminary theoretical foundation for further dissecting the genetic differences of japonica and indica rice in terms of the diversities and distributions of their component mPing.
Animals
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DNA Transposable Elements
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genetics
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Genome, Plant
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Oryza
;
classification
;
genetics
7.Cashmere goat bacterial artificial chromosome recombination and cell transfection system.
Tian HUANG ; Zhongyang CAO ; Yaohui YANG ; Gengsheng CAO
Chinese Journal of Biotechnology 2016;32(3):317-328
The Cashmere goat is mainly used to produce cashmere, which is very popular for its delicate fiber, luscious softness and natural excellent warm property. Keratin associated protein (KAP) and bone morphogenetic protein (BMP) of the Cashmere goat play an important role in the proliferation and development of cashmere fiber follicle cells. Bacterial artificial chromosome containing kap6.3, kap8.1 and bmp4 genes were used to increase the production and quality of Cashmere. First, we constructed bacterial artificial chromosomes by homology recombination. Then Tol2 transposon was inserted into bacterial artificial chromosomes that were then transfected into Cashmere goat fibroblasts by Amaxa Nucleofector technology according to the manufacture's instructions. We successfully constructed the BAC-Tol2 vectors containing target genes. Each vector contained egfp report gene with UBC promoter, Neomycin resistant gene for cell screening and two loxp elements for resistance removing after transfected into cells. The bacterial artificial chromosome-Tol2 vectors showed a high efficiency of transfection that can reach 1% to 6% with a highest efficiency of 10%. We also obtained Cashmere goat fibroblasts integrated exogenous genes (kap6.3, kap8.1 and bmp4) preparing for the clone of Cashmere goat in the future. Our research demonstrates that the insertion of Tol2 transposons into bacterial artificial chromosomes improves the transfection efficiency and accuracy of bacterial artificial chromosome error-free recombination.
Animals
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Bone Morphogenetic Proteins
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genetics
;
Chromosomes, Artificial, Bacterial
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DNA Transposable Elements
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Fibroblasts
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Goats
;
genetics
;
Keratins
;
genetics
;
Transfection
8.Comparative Evaluation of Several Gene Targets for Designing a Multiplex-PCR for an Early Diagnosis of Extrapulmonary Tuberculosis.
Ankush RAJ ; Netrapal SINGH ; Krishna B GUPTA ; Dhruva CHAUDHARY ; Aparna YADAV ; Anil CHAUDHARY ; Kshitij AGARWAL ; Mandira VARMA-BASIL ; Rajendra PRASAD ; Gopal K KHULLER ; Promod K MEHTA
Yonsei Medical Journal 2016;57(1):88-96
PURPOSE: Diagnosis of extrapulmonary tuberculosis (EPTB) poses serious challenges. A careful selection of appropriate gene targets is essential for designing a multiplex-polymerase chain reaction (M-PCR) assay. MATERIALS AND METHODS: We compared several gene targets of Mycobacterium tuberculosis, including IS6110, devR, and genes encoding MPB-64 (mpb64), 38kDa (pstS1), 65kDa (hsp65), 30kDa (fbpB), ESAT-6 (esat6), and CFP-10 (cfp10) proteins, using PCR assays on 105 EPTB specimens. From these data, we chose the two best gene targets to design an M-PCR. RESULTS: Among all gene targets tested, mpb64 showed the highest sensitivity (84% in confirmed cases and 77.5% in clinically suspected cases), followed by IS6110, hsp65, 38kDa, 30kDa, esat6, cfp10, and devR. We used mpb64+IS6110 for designing an M-PCR assay. Our M-PCR assay demonstrated a high sensitivity of 96% in confirmed EPTB cases and 88.75% in clinically suspected EPTB cases with a high specificity of 100%, taking clinical diagnosis as the gold standard. CONCLUSION: These M-PCR results along with the clinical findings may facilitate an early diagnosis of EPTB patients and clinical management of disease.
Bacteriological Techniques/methods
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DNA Transposable Elements/genetics
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DNA, Bacterial/analysis/genetics
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Early Diagnosis
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Female
;
Gene Amplification
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Humans
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Male
;
Multiplex Polymerase Chain Reaction/*methods
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Mycobacterium tuberculosis/genetics/*isolation & purification
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Polymerase Chain Reaction/*methods/standards
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Sensitivity and Specificity
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Tuberculosis/*diagnosis
9.PiggyBac transposon-mediated gene delivery efficiently generates stable transfectants derived from cultured primary human deciduous tooth dental pulp cells (HDDPCs) and HDDPC-derived iPS cells.
Emi INADA ; Issei SAITOH ; Satoshi WATANABE ; Reiji AOKI ; Hiromi MIURA ; Masato OHTSUKA ; Tomoya MURAKAMI ; Tadashi SAWAMI ; Youichi YAMASAKI ; Masahiro SATO
International Journal of Oral Science 2015;7(3):144-154
The ability of human deciduous tooth dental pulp cells (HDDPCs) to differentiate into odontoblasts that generate mineralized tissue holds immense potential for therapeutic use in the field of tooth regenerative medicine. Realization of this potential depends on efficient and optimized protocols for the genetic manipulation of HDDPCs. In this study, we demonstrate the use of a PiggyBac (PB)-based gene transfer system as a method for introducing nonviral transposon DNA into HDDPCs and HDDPC-derived inducible pluripotent stem cells. The transfection efficiency of the PB-based system was significantly greater than previously reported for electroporation-based transfection of plasmid DNA. Using the neomycin resistance gene as a selection marker, HDDPCs were stably transfected at a rate nearly 40-fold higher than that achieved using conventional methods. Using this system, it was also possible to introduce two constructs simultaneously into a single cell. The resulting stable transfectants, expressing tdTomato and enhanced green fluorescent protein, exhibited both red and green fluorescence. The established cell line did not lose the acquired phenotype over three months of culture. Based on our results, we concluded that PB is superior to currently available methods for introducing plasmid DNA into HDDPCs. There may be significant challenges in the direct clinical application of this method for human dental tissue engineering due to safety risks and ethical concerns. However, the high level of transfection achieved with PB may have significant advantages in basic scientific research for dental tissue engineering applications, such as functional studies of genes and proteins. Furthermore, it is a useful tool for the isolation of genetically engineered HDDPC-derived stem cells for studies in tooth regenerative medicine.
Cells, Cultured
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DNA Transposable Elements
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Dental Pulp
;
cytology
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Humans
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Induced Pluripotent Stem Cells
;
cytology
;
Nerve Tissue Proteins
;
genetics
;
Tooth, Deciduous
;
cytology
;
Transfection
10.Construction of a general piggyBac transposon inducible cell immortalization vector and verification of its basic properties.
Hui HUANG ; Guangdong HU ; Jian KANG ; Suzhu QING ; Yong ZHANG
Chinese Journal of Biotechnology 2014;30(8):1182-1192
In order to construct generally efficient cell immortalization vector, pTP-hTERT, we modified the traditional piggyBac (PB) transposon using artificial synthesis, PCR and enzyme digestion. The modified vector contained the necessary transposon elements, a PB transposase expression cassette, a co-expression selectable element and a human telomerase reverse transcriptase (hTERT) expression cassette. The co-expression selectable element had two markers, enhanced green fluorescent protein (EGFP) gene and puromycin-resistance (Puro) gene, linked by porcine teschovirus-1 2A peptide (P2A). To validate the functionality of vector elements, we transfected pTP-hTERT into HEK293 cell, selected the positive cell clones and then conducted RT-PCR, Western blotting (WB) and Tail-PCR, methylene blue staining and statistic analysis on selected cells. The results of sequencing and cell culture show that the pTP-hTERT was constructed successfully and the positive cell could be selected by puromycin. The WB results, P2A cutting EGFP and Puro fusion protein with high efficiency, reflected the selectable element worked. The sequencing result of Tail-PCR confirmed the vector integrated into the genome through transposition. The results of methylene blue staining and statistic analysis indicated the clone of positive cells triggered by pTP-hTERT significantly increased (P < 0.01) compared with control group. The construction of pTP-hTERT provides an efficient tool for establishing immortalized cell lines and a demonstration for building other eukaryotic plasmids.
Cell Line
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DNA Transposable Elements
;
genetics
;
Genetic Vectors
;
Green Fluorescent Proteins
;
genetics
;
HEK293 Cells
;
Humans
;
Plasmids
;
Polymerase Chain Reaction
;
Telomerase
;
genetics
;
Transfection

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