1
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Pathak RU, Phanindhar K, Mishra RK. Transposable elements as scaffold/matrix attachment regions: shaping organization and functions in genomes. Front Mol Biosci 2024; 10:1326933. [PMID: 38455359 PMCID: PMC10918478 DOI: 10.3389/fmolb.2023.1326933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Accepted: 12/27/2023] [Indexed: 03/09/2024] Open
Abstract
The hierarchical structure of eukaryotic genomes has regulatory layers, one of them being epigenetic "indexing" of the genome that leads to cell-type-specific patterns of gene expression. By establishing loops and defining chromatin domains, cells can achieve coordinated control over multi-locus segments of the genome. This is thought to be achieved using scaffold/matrix attachment regions (S/MARs) that establish structural and functional loops and topologically associating domains (TADs) that define a self-interacting region of the genome. Large-scale genome-wide mapping of S/MARs has begun to uncover these aspects of genome organization. A recent genome-wide study showed the association of transposable elements (TEs) with a significant fraction of S/MARs, suggesting that the multitude of TE-derived repeats constitute a class of anchorage sites of chromatin loops to nuclear architecture. In this study, we provide an insight that TE-driven dispersal of S/MARs has the potential to restructure the chromosomes by creating novel loops and domains. The combination of TEs and S/MARs, as elements that can hop through the genome along with regulatory capabilities, may provide an active mechanism of genome evolution leading to the emergence of novel features in biological systems. The significance is that a genome-wide study mapping developmental S/MARs reveals an intriguing link between these elements and TEs. This article highlights the potential of the TE-S/MAR combination to drive evolution by restructuring and shaping the genome.
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Affiliation(s)
| | | | - Rakesh K. Mishra
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
- Tata Institute for Genetics and Society, Bengaluru, India
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2
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Xu L, Zheng S, Witzel K, Van De Slijke E, Baekelandt A, Mylle E, Van Damme D, Cheng J, De Jaeger G, Inzé D, Jiang H. Chromatin attachment to the nuclear matrix represses hypocotyl elongation in Arabidopsis thaliana. Nat Commun 2024; 15:1286. [PMID: 38346986 PMCID: PMC10861482 DOI: 10.1038/s41467-024-45577-5] [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: 07/03/2023] [Accepted: 01/26/2024] [Indexed: 02/15/2024] Open
Abstract
The nuclear matrix is a nuclear compartment that has diverse functions in chromatin regulation and transcription. However, how this structure influences epigenetic modifications and gene expression in plants is largely unknown. In this study, we show that a nuclear matrix binding protein, AHL22, together with the two transcriptional repressors FRS7 and FRS12, regulates hypocotyl elongation by suppressing the expression of a group of genes known as SMALL AUXIN UP RNAs (SAURs) in Arabidopsis thaliana. The transcriptional repression of SAURs depends on their attachment to the nuclear matrix. The AHL22 complex not only brings these SAURs, which contain matrix attachment regions (MARs), to the nuclear matrix, but it also recruits the histone deacetylase HDA15 to the SAUR loci. This leads to the removal of H3 acetylation at the SAUR loci and the suppression of hypocotyl elongation. Taken together, our results indicate that MAR-binding proteins act as a hub for chromatin and epigenetic regulators. Moreover, we present a mechanism by which nuclear matrix attachment to chromatin regulates histone modifications, transcription, and hypocotyl elongation.
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Affiliation(s)
- Linhao Xu
- Leibniz Institute of Plant Genetics and Crop Plant Research, Gatersleben, 06466, Germany
| | - Shiwei Zheng
- Leibniz Institute of Plant Genetics and Crop Plant Research, Gatersleben, 06466, Germany
| | - Katja Witzel
- Leibniz Institute of Vegetable and Ornamental Crops, Großbeeren, 14979, Germany
| | - Eveline Van De Slijke
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, 9052, Belgium
- VIB Center for Plant Systems Biology, Ghent, 9052, Belgium
| | - Alexandra Baekelandt
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, 9052, Belgium
- VIB Center for Plant Systems Biology, Ghent, 9052, Belgium
| | - Evelien Mylle
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, 9052, Belgium
- VIB Center for Plant Systems Biology, Ghent, 9052, Belgium
| | - Daniel Van Damme
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, 9052, Belgium
- VIB Center for Plant Systems Biology, Ghent, 9052, Belgium
| | - Jinping Cheng
- Leibniz Institute of Plant Genetics and Crop Plant Research, Gatersleben, 06466, Germany
| | - Geert De Jaeger
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, 9052, Belgium
- VIB Center for Plant Systems Biology, Ghent, 9052, Belgium
| | - Dirk Inzé
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, 9052, Belgium
- VIB Center for Plant Systems Biology, Ghent, 9052, Belgium
| | - Hua Jiang
- Leibniz Institute of Plant Genetics and Crop Plant Research, Gatersleben, 06466, Germany.
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3
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Wheeler E, Brooks AM, Concia L, Vera DL, Wear EE, LeBlanc C, Ramu U, Vaughn MW, Bass HW, Martienssen RA, Thompson WF, Hanley-Bowdoin L. Arabidopsis DNA Replication Initiates in Intergenic, AT-Rich Open Chromatin. PLANT PHYSIOLOGY 2020; 183:206-220. [PMID: 32205451 PMCID: PMC7210620 DOI: 10.1104/pp.19.01520] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 03/03/2020] [Indexed: 05/04/2023]
Abstract
The selection and firing of DNA replication origins play key roles in ensuring that eukaryotes accurately replicate their genomes. This process is not well documented in plants due in large measure to difficulties in working with plant systems. We developed a new functional assay to label and map very early replicating loci that must, by definition, include at least a subset of replication origins. Arabidopsis (Arabidopsis thaliana) cells were briefly labeled with 5-ethynyl-2'-deoxy-uridine, and nuclei were subjected to two-parameter flow sorting. We identified more than 5500 loci as initiation regions (IRs), the first regions to replicate in very early S phase. These were classified as strong or weak IRs based on the strength of their replication signals. Strong initiation regions were evenly spaced along chromosomal arms and depleted in centromeres, while weak initiation regions were enriched in centromeric regions. IRs are AT-rich sequences flanked by more GC-rich regions and located predominantly in intergenic regions. Nuclease sensitivity assays indicated that IRs are associated with accessible chromatin. Based on these observations, initiation of plant DNA replication shows some similarity to, but is also distinct from, initiation in other well-studied eukaryotic systems.
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Affiliation(s)
- Emily Wheeler
- North Carolina State University, Department of Plant and Microbial Biology, Raleigh, North Carolina 27695
| | - Ashley M Brooks
- North Carolina State University, Department of Plant and Microbial Biology, Raleigh, North Carolina 27695
| | - Lorenzo Concia
- North Carolina State University, Department of Plant and Microbial Biology, Raleigh, North Carolina 27695
| | - Daniel L Vera
- Florida State University, Center for Genomics and Personalized Medicine, Tallahassee, Florida 32306
| | - Emily E Wear
- North Carolina State University, Department of Plant and Microbial Biology, Raleigh, North Carolina 27695
| | - Chantal LeBlanc
- Howard Hughes Medical Institute, Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724
| | - Umamaheswari Ramu
- Howard Hughes Medical Institute, Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724
| | - Matthew W Vaughn
- Texas Advanced Computing Center, University of Texas, Austin, Texas 78758
| | - Hank W Bass
- Florida State University, Department of Biological Science, Tallahassee, Florida 32306
| | - Robert A Martienssen
- Howard Hughes Medical Institute, Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724
| | - William F Thompson
- North Carolina State University, Department of Plant and Microbial Biology, Raleigh, North Carolina 27695
| | - Linda Hanley-Bowdoin
- North Carolina State University, Department of Plant and Microbial Biology, Raleigh, North Carolina 27695
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4
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Negrini F, O’Grady K, Hyvönen M, Folta KM, Baraldi E. Genomic structure and transcript analysis of the Rapid Alkalinization Factor (RALF) gene family during host-pathogen crosstalk in Fragaria vesca and Fragaria x ananassa strawberry. PLoS One 2020; 15:e0226448. [PMID: 32214345 PMCID: PMC7098601 DOI: 10.1371/journal.pone.0226448] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 03/01/2020] [Indexed: 11/19/2022] Open
Abstract
Rapid Alkalinization Factors (RALFs) are cysteine-rich peptides ubiquitous within plant kingdom. They play multiple roles as hormonal signals in diverse processes, including root elongation, cell growth, pollen tube development, and fertilization. Their involvement in host-pathogen crosstalk as negative regulators of immunity in Arabidopsis has also been recognized. In addition, peptides homologous to RALF are secreted by different fungal pathogens as effectors during early stages of infection. Previous studies have identified nine RALF genes in the diploid strawberry (Fragaria vesca) genome. This work describes the genomic organization of the RALF gene families in commercial octoploid strawberry (Fragaria × ananassa) and the re-annotated genome of F. vesca, and then compares findings with orthologs in Arabidopsis thaliana. We reveal the presence of 15 RALF genes in F. vesca genotype Hawaii 4 and 50 in Fragaria x ananassa cv. Camarosa, showing a non-homogenous localization of genes among the different Fragaria x ananassa subgenomes. Expression analysis of Fragaria x ananassa RALF genes upon infection with Colletotrichum acutatum or Botrytis cinerea showed that FanRALF3-1 was the only fruit RALF gene upregulated after fungal infection. In silico analysis was used to identify distinct pathogen inducible elements upstream of the FanRALF3-1 gene. Agroinfiltration of strawberry fruit with deletion constructs of the FanRALF3-1 promoter identified a 5' region required for FanRALF3-1 expression in fruit, but failed to identify a region responsible for fungal induced expression.
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Affiliation(s)
- Francesca Negrini
- Laboratory of Plant Pathology and Biotechnology, DISTAL, University of Bologna, Bologna Italy
- Horticultural Sciences Department, University of Florida, Gainesville, Florida, United States of America
| | - Kevin O’Grady
- Horticultural Sciences Department, University of Florida, Gainesville, Florida, United States of America
| | - Marko Hyvönen
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Kevin M. Folta
- Horticultural Sciences Department, University of Florida, Gainesville, Florida, United States of America
| | - Elena Baraldi
- Laboratory of Plant Pathology and Biotechnology, DISTAL, University of Bologna, Bologna Italy
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5
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Narwade N, Patel S, Alam A, Chattopadhyay S, Mittal S, Kulkarni A. Mapping of scaffold/matrix attachment regions in human genome: a data mining exercise. Nucleic Acids Res 2019; 47:7247-7261. [PMID: 31265077 PMCID: PMC6698742 DOI: 10.1093/nar/gkz562] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 06/08/2019] [Accepted: 06/27/2019] [Indexed: 11/14/2022] Open
Abstract
Scaffold/matrix attachment regions (S/MARs) are DNA elements that serve to compartmentalize the chromatin into structural and functional domains. These elements are involved in control of gene expression which governs the phenotype and also plays role in disease biology. Therefore, genome-wide understanding of these elements holds great therapeutic promise. Several attempts have been made toward identification of S/MARs in genomes of various organisms including human. However, a comprehensive genome-wide map of human S/MARs is yet not available. Toward this objective, ChIP-Seq data of 14 S/MAR binding proteins were analyzed and the binding site coordinates of these proteins were used to prepare a non-redundant S/MAR dataset of human genome. Along with co-ordinate (location) details of S/MARs, the dataset also revealed details of S/MAR features, namely, length, inter-SMAR length (the chromatin loop size), nucleotide repeats, motif abundance, chromosomal distribution and genomic context. S/MARs identified in present study and their subsequent analysis also suggests that these elements act as hotspots for integration of retroviruses. Therefore, these data will help toward better understanding of genome functioning and designing effective anti-viral therapeutics. In order to facilitate user friendly browsing and retrieval of the data obtained in present study, a web interface, MARome (http://bioinfo.net.in/MARome), has been developed.
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Affiliation(s)
- Nitin Narwade
- Bioinformatics Centre, Savitribai Phule Pune University, Pune - 411 007, Maharashtra, India
| | - Sonal Patel
- Chromatin and Disease Biology Lab, National Centre for Cell Science, Pune - 411 007, Maharashtra, India
| | - Aftab Alam
- Chromatin and Disease Biology Lab, National Centre for Cell Science, Pune - 411 007, Maharashtra, India
| | - Samit Chattopadhyay
- Chromatin and Disease Biology Lab, National Centre for Cell Science, Pune - 411 007, Maharashtra, India.,Indian Institute of Chemical Biology, 4, Raja S.C. Mullick Road, Jadavpur, Kolkata - 700 032, West Bengal, India
| | - Smriti Mittal
- Department of Biotechnology, Savitribai Phule Pune University, Pune - 411 007, Maharashtra, India
| | - Abhijeet Kulkarni
- Bioinformatics Centre, Savitribai Phule Pune University, Pune - 411 007, Maharashtra, India
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6
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Pérez-González A, Caro E. Benefits of using genomic insulators flanking transgenes to increase expression and avoid positional effects. Sci Rep 2019; 9:8474. [PMID: 31186481 PMCID: PMC6560062 DOI: 10.1038/s41598-019-44836-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 05/23/2019] [Indexed: 01/03/2023] Open
Abstract
For more than 20 years, plant biologists have tried to achieve complete control of transgene expression. Until the techniques to target transgenes to safe harbor sites in the genome become routine, flanking transgenes with genetic insulators, DNA sequences that create independent domains of gene expression, can help avoid positional effects and stabilize their expression. We have, for the first time, compared the effect of three insulator sequences previously described in the literature and one never tested before. Our results indicate that their use increases transgene expression, but only the last one reduces variability between lines and between individuals. We have analyzed the integration of insulator-flanked T-DNAs using whole genome re-sequencing (to our knowledge, also for the first time) and found data suggesting that chiMARs can shelter transgene insertions from neighboring repressive epigenetic states. Finally, we could also observe a loss of accuracy of the RB insertion in the lines harboring insulators, evidenced by a high frequency of truncation of T-DNAs and of insertion of vector backbone that, however, did not affect transgene expression. Our data supports that the effect of each genetic insulator is different and their use in transgenic constructs should depend on the needs of each specific experiment.
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Affiliation(s)
- Ana Pérez-González
- Centre for Plant Biotechnology and Genomics Universidad Politécnica de Madrid (UPM) - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA) Campus Montegancedo UPM Pozuelo de Alarcón (Madrid), Madrid, Spain
| | - Elena Caro
- Centre for Plant Biotechnology and Genomics Universidad Politécnica de Madrid (UPM) - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA) Campus Montegancedo UPM Pozuelo de Alarcón (Madrid), Madrid, Spain.
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7
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Sotelo-Silveira M, Chávez Montes RA, Sotelo-Silveira JR, Marsch-Martínez N, de Folter S. Entering the Next Dimension: Plant Genomes in 3D. TRENDS IN PLANT SCIENCE 2018; 23:598-612. [PMID: 29703667 DOI: 10.1016/j.tplants.2018.03.014] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 03/19/2018] [Accepted: 03/26/2018] [Indexed: 05/07/2023]
Abstract
After linear sequences of genomes and epigenomic landscape data, the 3D organization of chromatin in the nucleus is the next level to be explored. Different organisms present a general hierarchical organization, with chromosome territories at the top. Chromatin interaction maps, obtained by chromosome conformation capture (3C)-based methodologies, for eight plant species reveal commonalities, but also differences, among them and with animals. The smallest structures, found in high-resolution maps of the Arabidopsis genome, are single genes. Epigenetic marks (histone modification and DNA methylation), transcriptional activity, and chromatin interaction appear to be correlated, and whether structure is the cause or consequence of the function of interacting regions is being actively investigated.
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Affiliation(s)
- Mariana Sotelo-Silveira
- Departamento de Biología Vegetal, Laboratorio de Bioquímica, Facultad de Agronomía, Garzón 809, 12900 Montevideo, Uruguay
| | - Ricardo A Chávez Montes
- Unidad de Genómica Avanzada, Laboratorio Nacional de Genómica para la Biodiversidad (LANGEBIO), Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Km. 9.6 Libramiento Norte, Carretera Irapuato-León, 36824 Irapuato, Guanajuato, Mexico
| | - Jose R Sotelo-Silveira
- Department of Genomics, Instituto de Investigaciones Biológicas Clemente Estable, Av. Italia 3318, 11600 Montevideo, Uruguay; Sección Biología Celular, Dept. Cell and Molecular Biology, Facultad de Ciencias, Universidad de la Republica, Igua 4225, Montevideo, Uruguay
| | - Nayelli Marsch-Martínez
- Departamento de Biotecnología y Bioquímica, Unidad Irapuato, CINVESTAV-IPN, Km. 9.6 Libramiento Norte, Carretera Irapuato-León, 36824 Irapuato, Guanajuato, Mexico
| | - Stefan de Folter
- Unidad de Genómica Avanzada, Laboratorio Nacional de Genómica para la Biodiversidad (LANGEBIO), Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Km. 9.6 Libramiento Norte, Carretera Irapuato-León, 36824 Irapuato, Guanajuato, Mexico.
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8
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Chen SJ, Wang W, Zhang FY, Jia YL, Wang XY, Guo X, Chen SN, Gao JH, Wang TY. A chimeric HS4 insulator-scaffold attachment region enhances transgene expression in transfected Chinese hamster ovary cells. FEBS Open Bio 2017; 7:2021-2030. [PMID: 29226088 PMCID: PMC5715248 DOI: 10.1002/2211-5463.12335] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2017] [Revised: 09/23/2017] [Accepted: 10/03/2017] [Indexed: 11/12/2022] Open
Abstract
Chinese hamster ovary (CHO) cells are one of the most commonly used expression systems for the production of recombinant proteins but low levels of transgene expression and transgene silencing are frequently encountered. Epigenetic regulatory elements such as the chicken β-globin locus control region hypersensitive site 4 (HS4) and scaffold/matrix attachment regions (S/MARs) have positive effects on transgene expression. In this study, a chimeric HS4-SAR was cloned upstream or downstream of an enhanced green fluorescent protein (eGFP) expression cassette in a eukaryotic vector, and the resulting vectors were transfected into CHO cells. eGFP was detected by flow cytometry. Real-time quantitative PCR (qPCR) was used to determine copy numbers of the stably transfected cells. And fluorescence in situ hybridization (FISH) was used to detect the status of vector in the host cell chromosome. The results showed that HS4-SAR positioned downstream of the expression cassette could enhance eGFP expression by 4.83-fold compared with the control vector. There may not be a relationship between transgene copy number and gene expression level. HS4-SAR did not appear to alter the integration of the transgene into the host cell chromosome or its position in the chromosome. We found a synthetic chimeric HS4-SAR positively increased transgene expression in CHO cells.
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Affiliation(s)
- Si-Jia Chen
- Department of Biochemistry and Molecular Biology Xinxiang Medical University Henan China
| | - Wen Wang
- Pharmacy Collage Xinxiang Medical University Henan China.,Henan Collaborative Innovation Center of Molecular Diagnosis and Laboratory Medicine Xinxiang Medical University China
| | - Feng-Yi Zhang
- Grade 2012 The Third Clinical Medical College of Xinxiang Medical University Henan China
| | - Yan-Long Jia
- Pharmacy Collage Xinxiang Medical University Henan China.,Henan Collaborative Innovation Center of Molecular Diagnosis and Laboratory Medicine Xinxiang Medical University China
| | - Xiao-Yin Wang
- Department of Biochemistry and Molecular Biology Xinxiang Medical University Henan China
| | - Xiao Guo
- Pharmacy Collage Xinxiang Medical University Henan China
| | - Shao-Nan Chen
- Department of Biochemistry and Molecular Biology Xinxiang Medical University Henan China
| | - Jian-Hui Gao
- Department of Biochemistry and Molecular Biology Xinxiang Medical University Henan China
| | - Tian-Yun Wang
- Department of Biochemistry and Molecular Biology Xinxiang Medical University Henan China.,Henan Collaborative Innovation Center of Molecular Diagnosis and Laboratory Medicine Xinxiang Medical University China
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9
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Bi X, Cheng YJ, Hu B, Ma X, Wu R, Wang JW, Liu C. Nonrandom domain organization of the Arabidopsis genome at the nuclear periphery. Genome Res 2017; 27:1162-1173. [PMID: 28385710 PMCID: PMC5495068 DOI: 10.1101/gr.215186.116] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2016] [Accepted: 04/05/2017] [Indexed: 12/12/2022]
Abstract
The nuclear space is not a homogeneous biochemical environment. Many studies have demonstrated that the transcriptional activity of a gene is linked to its positioning within the nuclear space. Following the discovery of lamin-associated domains (LADs), which are transcriptionally repressed chromatin regions, the nonrandom positioning of chromatin at the nuclear periphery and its biological relevance have been studied extensively in animals. However, it remains unknown whether comparable chromatin organizations exist in plants. Here, using a strategy using restriction enzyme-mediated chromatin immunoprecipitation, we present genome-wide identification of nonrandom domain organization of chromatin at the peripheral zone of Arabidopsis thaliana nuclei. We show that in various tissues, 10%-20% of the regions on the chromosome arms are anchored at the nuclear periphery, and these regions largely overlap between different tissues. Unlike LADs in animals, the identified domains in plants are not gene-poor or A/T-rich. These domains are enriched with silenced protein-coding genes, transposable element genes, and heterochromatic marks, which collectively define a repressed environment. In addition, these domains strongly correlate with our genome-wide chromatin interaction data set (Hi-C) by largely explaining the patterns of chromatin compartments, revealed on Hi-C maps. Moreover, our results reveal a spatial compartment of different DNA methylation pathways that regulate silencing of transposable elements, where the CHH methylation of transposable elements located at the nuclear periphery and in the interior are preferentially mediated by CMT2 and DRM methyltransferases, respectively. Taken together, the results demonstrate functional partitioning of the Arabidopsis genome in the nuclear space.
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Affiliation(s)
- Xiuli Bi
- Center for Plant Molecular Biology (ZMBP), University of Tübingen, Tübingen 72076, Germany
| | - Ying-Juan Cheng
- National Key Laboratory of Plant Molecular Genetics (NKLPMG), CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology (SIPPE), Shanghai Institutes for Biological Sciences (SIBS), Shanghai 200032, People's Republic of China.,University of Chinese Academy of Sciences, Shanghai 200032, People's Republic of China
| | - Bo Hu
- Center for Plant Molecular Biology (ZMBP), University of Tübingen, Tübingen 72076, Germany
| | - Xiaoli Ma
- Center for Plant Molecular Biology (ZMBP), University of Tübingen, Tübingen 72076, Germany
| | - Rui Wu
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, Tübingen 72076, Germany
| | - Jia-Wei Wang
- National Key Laboratory of Plant Molecular Genetics (NKLPMG), CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology (SIPPE), Shanghai Institutes for Biological Sciences (SIBS), Shanghai 200032, People's Republic of China
| | - Chang Liu
- Center for Plant Molecular Biology (ZMBP), University of Tübingen, Tübingen 72076, Germany
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10
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Recurrence of Chromosome Rearrangements and Reuse of DNA Breakpoints in the Evolution of the Triticeae Genomes. G3-GENES GENOMES GENETICS 2016; 6:3837-3847. [PMID: 27729435 PMCID: PMC5144955 DOI: 10.1534/g3.116.035089] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Chromosomal rearrangements (CRs) play important roles in karyotype diversity and speciation. While many CR breakpoints have been characterized at the sequence level in yeast, insects, and primates, little is known about the structure of evolutionary CR breakpoints in plant genomes, which are much more dynamic in genome size and sequence organization. Here, we report identification of breakpoints of a translocation between chromosome arms 4L and 5L of Triticeae, which is fixed in several species, including diploid wheat and rye, by comparative mapping and analysis of the draft genome and chromosome survey sequences of the Triticeae species. The wheat translocation joined the ends of breakpoints downstream of a WD40 gene on 4AL and a gene of the PMEI family on 5AL. A basic helix-loop-helix transcription factor gene in 5AL junction was significantly restructured. Rye and wheat share the same position for the 4L breakpoint, but the 5L breakpoint positions are not identical, although very close in these two species, indicating the recurrence of 4L/5L translocations in the Triticeae. Although barley does not carry the translocation, collinearity across the breakpoints was violated by putative inversions and/or transpositions. Alignment with model grass genomes indicated that the translocation breakpoints coincided with ancient inversion junctions in the Triticeae ancestor. Our results show that the 4L/5L translocation breakpoints represent two CR hotspots reused during Triticeae evolution, and support breakpoint reuse as a widespread mechanism in all eukaryotes. The mechanisms of the recurrent translocation and its role in Triticeae evolution are also discussed.
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11
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Dumler JS, Sinclair SH, Pappas-Brown V, Shetty AC. Genome-Wide Anaplasma phagocytophilum AnkA-DNA Interactions Are Enriched in Intergenic Regions and Gene Promoters and Correlate with Infection-Induced Differential Gene Expression. Front Cell Infect Microbiol 2016; 6:97. [PMID: 27703927 PMCID: PMC5028410 DOI: 10.3389/fcimb.2016.00097] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 08/26/2016] [Indexed: 12/16/2022] Open
Abstract
Anaplasma phagocytophilum, an obligate intracellular prokaryote, infects neutrophils, and alters cardinal functions via reprogrammed transcription. Large contiguous regions of neutrophil chromosomes are differentially expressed during infection. Secreted A. phagocytophilum effector AnkA transits into the neutrophil or granulocyte nucleus to complex with DNA in heterochromatin across all chromosomes. AnkA binds to gene promoters to dampen cis-transcription and also has features of matrix attachment region (MAR)-binding proteins that regulate three-dimensional chromatin architecture and coordinate transcriptional programs encoded in topologically-associated chromatin domains. We hypothesize that identification of additional AnkA binding sites will better delineate how A. phagocytophilum infection results in reprogramming of the neutrophil genome. Using AnkA-binding ChIP-seq, we showed that AnkA binds broadly throughout all chromosomes in a reproducible pattern, especially at: (i) intergenic regions predicted to be MARs; (ii) within predicted lamina-associated domains; and (iii) at promoters ≤ 3000 bp upstream of transcriptional start sites. These findings provide genome-wide support for AnkA as a regulator of cis-gene transcription. Moreover, the dominant mark of AnkA in distal intergenic regions known to be AT-enriched, coupled with frequent enrichment in the nuclear lamina, provides strong support for its role as a MAR-binding protein and genome “re-organizer.” AnkA must be considered a prime candidate to promote neutrophil reprogramming and subsequent functional changes that belie improved microbial fitness and pathogenicity.
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Affiliation(s)
- J Stephen Dumler
- Department of Pathology, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences Bethesda, MD, USA
| | | | - Valeria Pappas-Brown
- Department of Pathology, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences Bethesda, MD, USA
| | - Amol C Shetty
- Informatics Resource Center, Institute for Genome Sciences, University of Maryland Baltimore, MD, USA
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Wang XJ, Wang J, Wang YY, Guo YJ, Chu BB, Yang GY. Sus scrofa matrix attachment region enhances expression of the PiggyBac system transfected into HEK293T cells. Biotechnol Lett 2016; 38:949-58. [PMID: 26965151 DOI: 10.1007/s10529-016-2074-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 03/01/2016] [Indexed: 10/22/2022]
Abstract
OBJECTIVES To determine the effects of the Sus scrofa matrix attachment region (SusMAR) on transgene expression in HEK293T cells. RESULTS Three expression vectors with the MAR at different sites in the PiggyBac (PB) transposon vector backbone were compared: two MARs flanking the β-galactosidase (β-gal) expression cassette, and one at the upstream or downstream site. Bos taurus MAR (BosMAR) and a β-gal expression cassette without MARs were the positive and negative controls, respectively. Compared to the control, β-gal activity of all SusMAR and BosMAR vectors was significantly improved in the presence of PB transposase (PBase). However, only the downstream SusMAR and upstream BosMAR vectors showed increased expression in the absence of PBase. Expression was significantly increased in all vectors with the PBase group compared to those without the PBase group. Gene copy numbers were not increased compared to the negative control. CONCLUSIONS SusMAR enhanced recombinant gene expression levels and stability in HEK293T cells, was not increase transgene copy number. These results could facilitate the development of vectors for stable production of therapeutic proteins.
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Affiliation(s)
- Xin-Jian Wang
- Key Laboratory of Animal Biochemistry and Nutrition, Ministry of Agriculture, Henan Agricultural University, Zhengzhou, Henan, China
| | - Jiang Wang
- Key Laboratory of Animal Biochemistry and Nutrition, Ministry of Agriculture, Henan Agricultural University, Zhengzhou, Henan, China
| | - Yue-Ying Wang
- Key Laboratory of Animal Biochemistry and Nutrition, Ministry of Agriculture, Henan Agricultural University, Zhengzhou, Henan, China
| | - Yu-Jie Guo
- Key Laboratory of Animal Biochemistry and Nutrition, Ministry of Agriculture, Henan Agricultural University, Zhengzhou, Henan, China
| | - Bei-Bei Chu
- Key Laboratory of Animal Biochemistry and Nutrition, Ministry of Agriculture, Henan Agricultural University, Zhengzhou, Henan, China
| | - Guo-Yu Yang
- College of Animal Husbandary and Veterinary Science, Henan Agricultural University, Wenhua Road 95, Zhengzhou, 450002, People's Republic of China.
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Noise-plasticity correlations of gene expression in the multicellular organism Arabidopsis thaliana. J Theor Biol 2015; 387:13-22. [PMID: 26431771 DOI: 10.1016/j.jtbi.2015.09.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Revised: 09/05/2015] [Accepted: 09/08/2015] [Indexed: 11/21/2022]
Abstract
Gene expression levels exhibit stochastic variations among genetically identical organisms under the same environmental conditions (called gene expression "noise" or phenotype "fluctuation"). In yeast and Escherichia coli, positive correlations have been found between such gene expression noise and "plasticity" with environmental variations. To determine the universality of such correlations in both unicellular and multicellular organisms, we focused on the relationships between gene expression "noise" and "plasticity" in Arabidopsis thaliana, a multicellular model organism. In recent studies on yeast and E. coli, only some gene groups with specific properties of promoter architecture, average expression levels, and functions exhibited strong noise-plasticity correlations. However, we found strong noise-plasticity correlations for most gene groups in Arabidopsis; additionally, promoter architecture, functional essentiality of genes, and circadian rhythm appeared to have only a weak influence on the correlation strength. The differences in the characteristics of noise-plasticity correlations may result from three-dimensional chromosomal structures and/or circadian rhythm.
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Abstract
Lowary and Widom selected from random sequences those which form exceptionally stable nucleosomes, including clone 601, the current champion of strong nucleosome (SN) sequences. This unique sequence database (LW sequences) carries sequence elements which confer stability on the nucleosomes formed on the sequences, and, thus, may serve as source of information on the structure of "ideal" or close to ideal nucleosome DNA sequence. An important clue is also provided by crystallographic study of Vasudevan and coauthors on clone 601 nucleosomes. It demonstrated that YR·YR dinucleotide stacks (primarily TA·TA) follow one another at distances 10 or 11 bases or multiples thereof, such that they all are located on the interface between DNA and histone octamer. Combining this important information with alignment of the YR-containing 10-mers and 11-mers from LW sequences, the bendability matrices of the stable nucleosome DNA are derived. The matrices suggest that the periodically repeated TA (YR), RR, and YY dinucleotides are the main sequence features of the SNs. This consensus coincides with the one for recently discovered SNs with visibly periodic DNA sequences. Thus, the experimentally observed stable LW nucleosomes and SNs derived computationally appear to represent the same entity - exceptionally stable SNs.
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Affiliation(s)
- Edward N Trifonov
- a Institute of Evolution , University of Haifa , Mount Carmel, 31905 Haifa , Israel
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15
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Zhao J, Favero DS, Qiu J, Roalson EH, Neff MM. Insights into the evolution and diversification of the AT-hook Motif Nuclear Localized gene family in land plants. BMC PLANT BIOLOGY 2014; 14:266. [PMID: 25311531 PMCID: PMC4209074 DOI: 10.1186/s12870-014-0266-7] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Accepted: 09/25/2014] [Indexed: 05/20/2023]
Abstract
BACKGROUND Members of the ancient land-plant-specific transcription factor AT-Hook Motif Nuclear Localized (AHL) gene family regulate various biological processes. However, the relationships among the AHL genes, as well as their evolutionary history, still remain unexplored. RESULTS We analyzed over 500 AHL genes from 19 land plant species, ranging from the early diverging Physcomitrella patens and Selaginella to a variety of monocot and dicot flowering plants. We classified the AHL proteins into three types (Type-I/-II/-III) based on the number and composition of their functional domains, the AT-hook motif(s) and PPC domain. We further inferred their phylogenies via Bayesian inference analysis and predicted gene gain/loss events throughout their diversification. Our analyses suggested that the AHL gene family emerged in embryophytes and further evolved into two distinct clades, with Type-I AHLs forming one clade (Clade-A), and the other two types together diversifying in another (Clade-B). The two AHL clades likely diverged before the separation of Physcomitrella patens from the vascular plant lineage. In angiosperms, Clade-A AHLs expanded into 5 subfamilies; while, the ones in Clade-B expanded into 4 subfamilies. Examination of their expression patterns suggests that the AHLs within each clade share similar expression patterns with each other; however, AHLs in one monophyletic clade exhibit distinct expression patterns from the ones in the other clade. Over-expression of a Glycine max AHL PPC domain in Arabidopsis thaliana recapitulates the phenotype observed when over-expressing its Arabidopsis thaliana counterpart. This result suggests that the AHL genes from different land plant species may share conserved functions in regulating plant growth and development. Our study further suggests that such functional conservation may be due to conserved physical interactions among the PPC domains of AHL proteins. CONCLUSIONS Our analyses reveal a possible evolutionary scenario for the AHL gene family in land plants, which will facilitate the design of new studies probing their biological functions. Manipulating the AHL genes has been suggested to have tremendous effects in agriculture through increased seedling establishment, enhanced plant biomass and improved plant immunity. The information gleaned from this study, in turn, has the potential to be utilized to further improve crop production.
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Affiliation(s)
- Jianfei Zhao
- />Molecular Plant Sciences Graduate Program, Washington State University, Pullman, WA 99164 USA
- />Department of Crop and Soil Sciences, Washington State University, Pullman, WA 99164 USA
- />Present Address: Department of Biology, University of Pennsylvania, Philadelphia, PA 19104 USA
| | - David S Favero
- />Molecular Plant Sciences Graduate Program, Washington State University, Pullman, WA 99164 USA
- />Department of Crop and Soil Sciences, Washington State University, Pullman, WA 99164 USA
| | - Jiwen Qiu
- />Department of Crop and Soil Sciences, Washington State University, Pullman, WA 99164 USA
| | - Eric H Roalson
- />Molecular Plant Sciences Graduate Program, Washington State University, Pullman, WA 99164 USA
- />School of Biological Sciences, Washington State University, Pullman, WA 99164 USA
| | - Michael M Neff
- />Molecular Plant Sciences Graduate Program, Washington State University, Pullman, WA 99164 USA
- />Department of Crop and Soil Sciences, Washington State University, Pullman, WA 99164 USA
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Turan S, Qiao J, Madden S, Benham C, Kotz M, Schambach A, Bode J. Expanding Flp-RMCE options: the potential of Recombinase Mediated Twin-Site Targeting (RMTT). Gene 2014; 546:135-44. [DOI: 10.1016/j.gene.2014.06.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Accepted: 06/02/2014] [Indexed: 01/02/2023]
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