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Raabe K, Sun L, Schindfessel C, Honys D, Geelen D. A word of caution: T-DNA-associated mutagenesis in plant reproduction research. JOURNAL OF EXPERIMENTAL BOTANY 2024; 75:3248-3258. [PMID: 38477707 DOI: 10.1093/jxb/erae114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Accepted: 03/12/2024] [Indexed: 03/14/2024]
Abstract
T-DNA transformation is prevalent in Arabidopsis research and has expanded to a broad range of crops and model plants. While major progress has been made in optimizing the Agrobacterium-mediated transformation process for various species, a variety of pitfalls associated with the T-DNA insertion may lead to the misinterpretation of T-DNA mutant analysis. Indeed, secondary mutagenesis either on the integration site or elsewhere in the genome, together with epigenetic interactions between T-DNA inserts or frequent genomic rearrangements, can be tricky to differentiate from the effect of the knockout of the gene of interest. These are mainly the case for genomic rearrangements that become balanced in filial generations without consequential phenotypical defects, which may be confusing particularly for studies that aim to investigate fertility and gametogenesis. As a cautionary note to the plant research community studying gametogenesis, we here report an overview of the consequences of T-DNA-induced secondary mutagenesis with emphasis on the genomic imbalance on gametogenesis. Additionally, we present a simple guideline to evaluate the T-DNA-mutagenized transgenic lines to decrease the risk of faulty analysis with minimal experimental effort.
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Affiliation(s)
- Karel Raabe
- Laboratory of Pollen Biology, Institute of Experimental Botany of the Czech Academy of Sciences, Rozvojová 263, 165 02 Prague 6, Czech Republic
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Viničná 5, 128 44 Prague 2, Czech Republic
| | - Limin Sun
- Horticell, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| | - Cédric Schindfessel
- Horticell, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| | - David Honys
- Laboratory of Pollen Biology, Institute of Experimental Botany of the Czech Academy of Sciences, Rozvojová 263, 165 02 Prague 6, Czech Republic
| | - Danny Geelen
- Horticell, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent, Belgium
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Li NN, Lun DX, Gong N, Meng G, Du XY, Wang H, Bao X, Li XY, Song JW, Hu K, Li L, Li SY, Liu W, Zhu W, Zhang Y, Li J, Yao T, Mou L, Han X, Hao F, Hu Y, Liu L, Zhu H, Wu Y, Liu B. Targeting the chromatin structural changes of antitumor immunity. J Pharm Anal 2024; 14:100905. [PMID: 38665224 PMCID: PMC11043877 DOI: 10.1016/j.jpha.2023.11.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 09/28/2023] [Accepted: 11/21/2023] [Indexed: 04/28/2024] Open
Abstract
Epigenomic imbalance drives abnormal transcriptional processes, promoting the onset and progression of cancer. Although defective gene regulation generally affects carcinogenesis and tumor suppression networks, tumor immunogenicity and immune cells involved in antitumor responses may also be affected by epigenomic changes, which may have significant implications for the development and application of epigenetic therapy, cancer immunotherapy, and their combinations. Herein, we focus on the impact of epigenetic regulation on tumor immune cell function and the role of key abnormal epigenetic processes, DNA methylation, histone post-translational modification, and chromatin structure in tumor immunogenicity, and introduce these epigenetic research methods. We emphasize the value of small-molecule inhibitors of epigenetic modulators in enhancing antitumor immune responses and discuss the challenges of developing treatment plans that combine epigenetic therapy and immunotherapy through the complex interaction between cancer epigenetics and cancer immunology.
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Affiliation(s)
- Nian-nian Li
- Weifang People's Hospital, Weifang, Shandong, 261000, China
- School of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Deng-xing Lun
- Weifang People's Hospital, Weifang, Shandong, 261000, China
| | - Ningning Gong
- Weifang Traditional Chinese Medicine Hospital, Weifang, Shandong, 261000, China
| | - Gang Meng
- Shaanxi Key Laboratory of Sericulture, Ankang University, Ankang, Shaanxi, 725000, China
| | - Xin-ying Du
- Weifang People's Hospital, Weifang, Shandong, 261000, China
| | - He Wang
- Weifang People's Hospital, Weifang, Shandong, 261000, China
| | - Xiangxiang Bao
- Weifang People's Hospital, Weifang, Shandong, 261000, China
| | - Xin-yang Li
- Guizhou Education University, Guiyang, 550018, China
| | - Ji-wu Song
- Weifang People's Hospital, Weifang, Shandong, 261000, China
| | - Kewei Hu
- Weifang Traditional Chinese Medicine Hospital, Weifang, Shandong, 261000, China
| | - Lala Li
- Guizhou Normal University, Guiyang, 550025, China
| | - Si-ying Li
- Weifang People's Hospital, Weifang, Shandong, 261000, China
| | - Wenbo Liu
- Weifang People's Hospital, Weifang, Shandong, 261000, China
| | - Wanping Zhu
- Weifang People's Hospital, Weifang, Shandong, 261000, China
| | - Yunlong Zhang
- School of Medical Imaging, Weifang Medical University, Weifang, Shandong, 261053, China
| | - Jikai Li
- Department of Bone and Soft Tissue Oncology, Tianjin Hospital, Tianjin, 300299, China
| | - Ting Yao
- School of Life Sciences, Nankai University, Tianjin, 300071, China
- Teda Institute of Biological Sciences & Biotechnology, Nankai University, Tianjin, 300457, China
| | - Leming Mou
- Weifang People's Hospital, Weifang, Shandong, 261000, China
| | - Xiaoqing Han
- Weifang People's Hospital, Weifang, Shandong, 261000, China
| | - Furong Hao
- Weifang People's Hospital, Weifang, Shandong, 261000, China
| | - Yongcheng Hu
- Weifang People's Hospital, Weifang, Shandong, 261000, China
| | - Lin Liu
- School of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Hongguang Zhu
- Weifang People's Hospital, Weifang, Shandong, 261000, China
| | - Yuyun Wu
- Xinqiao Hospital of Army Military Medical University, Chongqing, 400038, China
| | - Bin Liu
- Weifang People's Hospital, Weifang, Shandong, 261000, China
- School of Life Sciences, Nankai University, Tianjin, 300071, China
- Teda Institute of Biological Sciences & Biotechnology, Nankai University, Tianjin, 300457, China
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3
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Pucker B, Kleinbölting N, Weisshaar B. Large scale genomic rearrangements in selected Arabidopsis thaliana T-DNA lines are caused by T-DNA insertion mutagenesis. BMC Genomics 2021; 22:599. [PMID: 34362298 PMCID: PMC8348815 DOI: 10.1186/s12864-021-07877-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Accepted: 07/06/2021] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND Experimental proof of gene function assignments in plants is based on mutant analyses. T-DNA insertion lines provided an invaluable resource of mutants and enabled systematic reverse genetics-based investigation of the functions of Arabidopsis thaliana genes during the last decades. RESULTS We sequenced the genomes of 14 A. thaliana GABI-Kat T-DNA insertion lines, which eluded flanking sequence tag-based attempts to characterize their insertion loci, with Oxford Nanopore Technologies (ONT) long reads. Complex T-DNA insertions were resolved and 11 previously unknown T-DNA loci identified, resulting in about 2 T-DNA insertions per line and suggesting that this number was previously underestimated. T-DNA mutagenesis caused fusions of chromosomes along with compensating translocations to keep the gene set complete throughout meiosis. Also, an inverted duplication of 800 kbp was detected. About 10 % of GABI-Kat lines might be affected by chromosomal rearrangements, some of which do not involve T-DNA. Local assembly of selected reads was shown to be a computationally effective method to resolve the structure of T-DNA insertion loci. We developed an automated workflow to support investigation of long read data from T-DNA insertion lines. All steps from DNA extraction to assembly of T-DNA loci can be completed within days. CONCLUSIONS Long read sequencing was demonstrated to be an effective way to resolve complex T-DNA insertions and chromosome fusions. Many T-DNA insertions comprise not just a single T-DNA, but complex arrays of multiple T-DNAs. It is becoming obvious that T-DNA insertion alleles must be characterized by exact identification of both T-DNA::genome junctions to generate clear genotype-to-phenotype relations.
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Affiliation(s)
- Boas Pucker
- Genetics and Genomics of Plants, Center for Biotechnology (CeBiTec), Bielefeld University, Sequenz 1, 33615 Bielefeld, Germany
- Evolution and Diversity, Department of Plant Sciences, University of Cambridge, Cambridge, UK
| | - Nils Kleinbölting
- Bioinformatics Resource Facility, Center for Biotechnology (CeBiTec, Bielefeld University, Sequenz 1, 33615 Bielefeld, Germany
| | - Bernd Weisshaar
- Genetics and Genomics of Plants, Center for Biotechnology (CeBiTec), Bielefeld University, Sequenz 1, 33615 Bielefeld, Germany
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Smith PJ, O'Neill MA, Backe J, York WS, Peña MJ, Urbanowicz BR. Analytical Techniques for Determining the Role of Domain of Unknown Function 579 Proteins in the Synthesis of O-Methylated Plant Polysaccharides. SLAS Technol 2020; 25:345-355. [PMID: 32204644 DOI: 10.1177/2472630320912692] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Matrix polysaccharides are a diverse group of structurally complex carbohydrates and account for a large portion of the biomass consumed as food or used to produce fuels and materials. Glucuronoxylan and arabinogalactan protein are matrix glycans that have sidechains decorated with 4-O-methyl glucuronosyl residues. Methylation is a key determinant of the physical properties of these wall glycopolymers and consequently affects both their biological function and ability to interact with other wall polymers. Indeed, there is increasing interest in determining the distribution and abundance of methyl-etherified polysaccharides in different plant species, tissues, and developmental stages. There is also a need to understand the mechanisms involved in their biosynthesis. Members of the Domain of Unknown Function (DUF) 579 family have been demonstrated to have a role in the biosynthesis of methyl-etherified glycans. Here we describe methods for the analysis of the 4-O-methyl glucuronic acid moieties that are present in sidechains of arabinogalactan proteins. These methods are then applied toward the analysis of loss-of-function mutants of two DUF579 family members that lack this modification in muro. We also present a procedure to assay DUF579 family members for enzymatic activity in vitro using acceptor oligosaccharides prepared from xylan of loss-of-function mutants. Our approach facilitates the characterization of enzymes that modify glycosyl residues during cell wall synthesis and the structures that they generate.
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Affiliation(s)
- Peter J Smith
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, USA.,Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, USA.,Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, OakRidge, TN, USA
| | - Malcolm A O'Neill
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, USA
| | - Jason Backe
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, USA.,Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, USA.,Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, OakRidge, TN, USA
| | - William S York
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, USA.,Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, USA.,Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, OakRidge, TN, USA
| | - Maria J Peña
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, USA.,Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, OakRidge, TN, USA
| | - Breeanna R Urbanowicz
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, USA.,Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, USA.,Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, OakRidge, TN, USA
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Aulakh K, Durrett TP. The Plastid Lipase PLIP1 Is Critical for Seed Viability in diacylglycerol acyltransferase1 Mutant Seed. PLANT PHYSIOLOGY 2019; 180:1962-1974. [PMID: 31221730 PMCID: PMC6670099 DOI: 10.1104/pp.19.00600] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 06/05/2019] [Indexed: 05/20/2023]
Abstract
In developing Arabidopsis (Arabidopsis thaliana) seeds, the synthesis of triacylglycerol (TAG) is mediated primarily by the acyl-CoA-dependent enzyme diacylglycerol acyltransferase1 (DGAT1). In the absence of DGAT1 activity, phospholipid:diacylglycerol acyltransferase (PDAT1) plays an important role in TAG synthesis, consistent with the higher-than-expected oil content and altered fatty acid composition of dgat1 seed. Transcript profiling of developing wild type (Columbia-0) and dgat1-1 mutant seed identified 602 differentially expressed genes. Expression of genes important for the formation of phosphatidylcholine, including LYSOPHOSPHATIDYLCHOLINE ACYLTRANSFERASE2, and REDUCED OLEATE DESATURATION1 were strongly upregulated, consistent with increased substrate supply for PDAT1. In addition, several genes lacking a defined role in TAG biosynthesis were also upregulated, including the α/β-hydrolase family gene PLIP1, which encodes a plastid-localized lipase. In most tissues, PLIP1 was expressed at equivalent levels in wild-type and dgat1 plants, except for developing seed, where transcript levels were higher in the dgat1 mutant. Seeds from plip1 mutant plants possessed a 20% reduction in oil content and were smaller than seed from wild-type plants. Crosses between dgat1 and plip1 failed to generate double-homozygous mutant plants. Reciprocal crossing with wild-type plants demonstrated that both male and female gametophytes could transmit the dgat1 plip1 double-mutant genotype. Double-homozygous dgat1 plip1 seed formed but was green and failed to germinate. The synthetic lethal phenotype of dgat1 with plip1 indicates an important role for PLIP1 in the absence of DGAT1 activity, likely by supplying polyunsaturated fatty acid substrates for PDAT1.
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Affiliation(s)
- Karanbir Aulakh
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, Kansas 66506
| | - Timothy P Durrett
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, Kansas 66506
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Patel JS, Sarma BK. Designing and experimental evaluation of gene-specific primers of pea ( Pisum sativum) defense proteins. 3 Biotech 2018; 8:482. [PMID: 30456016 DOI: 10.1007/s13205-018-1508-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 11/07/2018] [Indexed: 11/25/2022] Open
Abstract
Real-time gene expression analysis by semi-quantitative and quantitative RT-PCR requires a set of gene-specific primers which should have the ability to amplify the gene of interest specifically. In the present study, we have standardized certain parameters for primer design using the freely available Primer3 software. We have designed the primers for defense genes such as ICS (isochorismate synthase), CCoAOMT (caffeoyl CoA O-methyltransferase), C4H (cinnamate 4-hydroxylase), and G-alpha in pea. We have also discussed, the way of sequence retrieval, when the sequence is not reported in the organism of interest. We have evaluated the designed primers using cDNA prepared from mRNA isolated from the pea leaves. By analyzing the results, we have found that primers are perfectly binding with the target and giving single sharp band on a DNA electrophoresis gel. It can be concluded that the parameters used for primer designing by Primer3 play a critical role in the experimental results and parameters defined in the present study resulting in a very good amplification during PCR.
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Affiliation(s)
- Jai Singh Patel
- 1Department of Plant Food and Environmental Sciences, Dalhousie University, Halifax, NS Canada
| | - Birinchi Kumar Sarma
- 2Department of Mycology and Plant Pathology, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, India
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Kleinboelting N, Huep G, Weisshaar B. Enhancing the GABI-Kat Arabidopsis thaliana T-DNA Insertion Mutant Database by Incorporating Araport11 Annotation. PLANT & CELL PHYSIOLOGY 2017; 58:e7. [PMID: 28013277 PMCID: PMC5444572 DOI: 10.1093/pcp/pcw205] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Accepted: 11/11/2016] [Indexed: 05/29/2023]
Abstract
SimpleSearch provides access to a database containing information about T-DNA insertion lines of the GABI-Kat collection of Arabidopsis thaliana mutants. These mutants are an important tool for reverse genetics, and GABI-Kat is the second largest collection of such T-DNA insertion mutants. Insertion sites were deduced from flanking sequence tags (FSTs), and the database contains information about mutant plant lines as well as insertion alleles. Here, we describe improvements within the interface (available at http://www.gabi-kat.de/db/genehits.php) and with regard to the database content that have been realized in the last five years. These improvements include the integration of the Araport11 genome sequence annotation data containing the recently updated A. thaliana structural gene descriptions, an updated visualization component that displays groups of insertions with very similar insertion positions, mapped confirmation sequences, and primers. The visualization component provides a quick way to identify insertions of interest, and access to improved data about the exact structure of confirmed insertion alleles. In addition, the database content has been extended by incorporating additional insertion alleles that were detected during the confirmation process, as well as by adding new FSTs that have been produced during continued efforts to complement gaps in FST availability. Finally, the current database content regarding predicted and confirmed insertion alleles as well as primer sequences has been made available as downloadable flat files.
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Affiliation(s)
- Nils Kleinboelting
- Center for Biotechnology and Department of Biology, Bielefeld University, Universitaetsstrasse 25, D-33615 Bielefeld, Germany
| | - Gunnar Huep
- Center for Biotechnology and Department of Biology, Bielefeld University, Universitaetsstrasse 25, D-33615 Bielefeld, Germany
| | - Bernd Weisshaar
- Center for Biotechnology and Department of Biology, Bielefeld University, Universitaetsstrasse 25, D-33615 Bielefeld, Germany
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Kleinboelting N, Huep G, Appelhagen I, Viehoever P, Li Y, Weisshaar B. The Structural Features of Thousands of T-DNA Insertion Sites Are Consistent with a Double-Strand Break Repair-Based Insertion Mechanism. MOLECULAR PLANT 2015; 8:1651-64. [PMID: 26343971 DOI: 10.1016/j.molp.2015.08.011] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Revised: 07/28/2015] [Accepted: 08/13/2015] [Indexed: 05/06/2023]
Abstract
Transformation by Agrobacterium tumefaciens, an important tool in modern plant research, involves the integration of T-DNA initially present on a plasmid in agrobacteria into the genome of plant cells. The process of attachment of the agrobacteria to plant cells and the transport of T-DNA into the cell and further to the nucleus has been well described. However, the exact mechanism of integration into the host's DNA is still unclear, although several models have been proposed. During confirmation of T-DNA insertion alleles from the GABI-Kat collection of Arabidopsis thaliana mutants, we have generated about 34,000 sequences from the junctions between inserted T-DNA and adjacent genome regions. Here, we describe the evaluation of this dataset with regard to existing models for T-DNA integration. The results suggest that integration into the plant genome is mainly mediated by the endogenous plant DNA repair machinery. The observed integration events showed characteristics highly similar to those of repair sites of double-strand breaks with respect to microhomology and deletion sizes. In addition, we describe unexpected integration events, such as large deletions and inversions at the integration site that are relevant for correct interpretation of results from T-DNA insertion mutants in reverse genetics experiments.
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Affiliation(s)
- Nils Kleinboelting
- Center for Biotechnology & Department of Biology, Bielefeld University, Universitaetsstrasse 25, 33615 Bielefeld, Germany
| | - Gunnar Huep
- Center for Biotechnology & Department of Biology, Bielefeld University, Universitaetsstrasse 25, 33615 Bielefeld, Germany
| | - Ingo Appelhagen
- Center for Biotechnology & Department of Biology, Bielefeld University, Universitaetsstrasse 25, 33615 Bielefeld, Germany
| | - Prisca Viehoever
- Center for Biotechnology & Department of Biology, Bielefeld University, Universitaetsstrasse 25, 33615 Bielefeld, Germany
| | - Yong Li
- Department of Medicine IV, University Hospital Freiburg, Berliner Allee 29, 79110 Freiburg, Germany
| | - Bernd Weisshaar
- Center for Biotechnology & Department of Biology, Bielefeld University, Universitaetsstrasse 25, 33615 Bielefeld, Germany.
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