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Zhou J, Lei X, Shafiq S, Zhang W, Li Q, Li K, Zhu J, Dong Z, He XJ, Sun Q. DDM1-mediated R-loop resolution and H2A.Z exclusion facilitates heterochromatin formation in Arabidopsis. SCIENCE ADVANCES 2023; 9:eadg2699. [PMID: 37566662 PMCID: PMC10421056 DOI: 10.1126/sciadv.adg2699] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 07/13/2023] [Indexed: 08/13/2023]
Abstract
Programmed constitutive heterochromatin silencing is essential for eukaryotic genome regulation, yet the initial step of this process is ambiguous. A large proportion of R-loops (RNA:DNA hybrids) had been unexpectedly identified within Arabidopsis pericentromeric heterochromatin with unknown functions. Through a genome-wide R-loop profiling screen, we find that DDM1 (decrease in DNA methylation 1) is the primary restrictor of pericentromeric R-loops via its RNA:DNA helicase activity. Low levels of pericentromeric R-loops resolved by DDM1 cotranscriptionally can facilitate constitutive heterochromatin silencing. Furthermore, we demonstrate that DDM1 physically excludes histone H2A variant H2A.Z and promotes H2A.W deposition for faithful heterochromatin initiation soon after R-loop clearance. The dual functions of DDM1 in R-loop resolution and H2A.Z eviction are essential for sperm nuclei structure maintenance in mature pollen. Our work unravels the cotranscriptional R-loop resolution coupled with accurate H2A variants deposition is the primary step of constitutive heterochromatin silencing in Arabidopsis, which might be conserved across eukaryotes.
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Affiliation(s)
- Jincong Zhou
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
| | - Xue Lei
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
| | - Sarfraz Shafiq
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
| | - Weifeng Zhang
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
| | - Qin Li
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
| | - Kuan Li
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
| | - Jiafu Zhu
- School of Life Sciences, Guangzhou University, Guangzhou 510006, China
| | - Zhicheng Dong
- School of Life Sciences, Guangzhou University, Guangzhou 510006, China
| | - Xin-jian He
- National Institute of Biological Sciences, Beijing, China
| | - Qianwen Sun
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
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2
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Vaquero-Sedas MI, Vega-Palas MA. Epigenetic nature of Arabidopsis thaliana telomeres. PLANT PHYSIOLOGY 2023; 191:47-55. [PMID: 36218957 PMCID: PMC9806604 DOI: 10.1093/plphys/kiac471] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 09/22/2022] [Indexed: 05/15/2023]
Abstract
The epigenetic features of defined chromosomal domains condition their biochemical and functional properties. Therefore, there is considerable interest in studying the epigenetic marks present at relevant chromosomal loci. Telomeric regions, which include telomeres and subtelomeres, have been traditionally considered heterochromatic. However, whereas the heterochromatic nature of subtelomeres has been widely accepted, the epigenetic status of telomeres remains controversial. Here, we studied the epigenetic features of Arabidopsis (Arabidopsis thaliana) telomeres by analyzing multiple genome-wide ChIP-seq experiments. Our analyses revealed that Arabidopsis telomeres are not significantly enriched either in euchromatic marks like H3K4me2, H3K9ac, and H3K27me3 or in heterochromatic marks such as H3K27me1 and H3K9me2. Thus, telomeric regions in Arabidopsis have a bimodal chromatin organization with telomeres lacking significant levels of canonical euchromatic and heterochromatic marks followed by heterochromatic subtelomeres. Since heterochromatin is known to influence telomere function, the heterochromatic modifications present at Arabidopsis subtelomeres could play a relevant role in telomere biology.
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Affiliation(s)
- María I Vaquero-Sedas
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC-Universidad de Sevilla, IBVF (CSIC-US), Seville E41092, Spain
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3
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Ma X, Feng Y, Yang Y, Li X, Shi Y, Tao S, Cheng X, Huang J, Wang XE, Chen C, Monchaud D, Zhang W. Genome-wide characterization of i-motifs and their potential roles in the stability and evolution of transposable elements in rice. Nucleic Acids Res 2022; 50:3226-3238. [PMID: 35188565 PMCID: PMC8989525 DOI: 10.1093/nar/gkac121] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 01/13/2022] [Accepted: 02/07/2022] [Indexed: 12/15/2022] Open
Abstract
I-motifs (iMs) are non-canonical DNA secondary structures that fold from cytosine (C)-rich genomic DNA regions termed putative i-motif forming sequences (PiMFSs). The structure of iMs is stabilized by hemiprotonated C-C base pairs, and their functions are now suspected in key cellular processes in human cells such as genome stability and regulation of gene transcription. In plants, their biological relevance is still largely unknown. Here, we characterized PiMFSs with high potential for i-motif formation in the rice genome by developing and applying a protocol hinging on an iMab antibody-based immunoprecipitation (IP) coupled with high-throughput sequencing (seq), consequently termed iM-IP-seq. We found that PiMFSs had intrinsic subgenomic distributions, cis-regulatory functions and an intricate relationship with DNA methylation. We indeed found that the coordination of PiMFSs with DNA methylation may affect dynamics of transposable elements (TEs) among different cultivated Oryza subpopulations or during evolution of wild rice species. Collectively, our study provides first and unique insights into the biology of iMs in plants, with potential applications in plant biotechnology for improving important agronomic rice traits.
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Affiliation(s)
- Xing Ma
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Collaborative Innovation Center for Modern Crop Production co-sponsored by Province and Ministry (CIC-MCP), Nanjing Agricultural University, No.1 Weigang, Nanjing, Jiangsu 210095, P.R. China
| | - Yilong Feng
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Collaborative Innovation Center for Modern Crop Production co-sponsored by Province and Ministry (CIC-MCP), Nanjing Agricultural University, No.1 Weigang, Nanjing, Jiangsu 210095, P.R. China
| | - Ying Yang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Collaborative Innovation Center for Modern Crop Production co-sponsored by Province and Ministry (CIC-MCP), Nanjing Agricultural University, No.1 Weigang, Nanjing, Jiangsu 210095, P.R. China
| | - Xin Li
- Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, Hunan410125, P.R. China
| | - Yining Shi
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Collaborative Innovation Center for Modern Crop Production co-sponsored by Province and Ministry (CIC-MCP), Nanjing Agricultural University, No.1 Weigang, Nanjing, Jiangsu 210095, P.R. China
| | - Shentong Tao
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Collaborative Innovation Center for Modern Crop Production co-sponsored by Province and Ministry (CIC-MCP), Nanjing Agricultural University, No.1 Weigang, Nanjing, Jiangsu 210095, P.R. China
| | - Xuejiao Cheng
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Collaborative Innovation Center for Modern Crop Production co-sponsored by Province and Ministry (CIC-MCP), Nanjing Agricultural University, No.1 Weigang, Nanjing, Jiangsu 210095, P.R. China
| | - Jian Huang
- School of Biology & Basic Medical Science, Soochow University, Suzhou, Jiangsu 215123, P.R. China
| | - Xiu-e Wang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Collaborative Innovation Center for Modern Crop Production co-sponsored by Province and Ministry (CIC-MCP), Nanjing Agricultural University, No.1 Weigang, Nanjing, Jiangsu 210095, P.R. China
| | - Caiyan Chen
- Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, Hunan410125, P.R. China
| | - David Monchaud
- Institut de Chimie Moleculaire, ICMUB CNRS UMR 6302, UBFC Dijon, France
| | - Wenli Zhang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Collaborative Innovation Center for Modern Crop Production co-sponsored by Province and Ministry (CIC-MCP), Nanjing Agricultural University, No.1 Weigang, Nanjing, Jiangsu 210095, P.R. China
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4
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Farrell C, Vaquero-Sedas MI, Cubiles MD, Thompson M, Vega-Vaquero A, Pellegrini M, Vega-Palas MA. A complex network of interactions governs DNA methylation at telomeric regions. Nucleic Acids Res 2022; 50:1449-1464. [PMID: 35061900 PMCID: PMC8860613 DOI: 10.1093/nar/gkac012] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 01/10/2022] [Indexed: 12/13/2022] Open
Abstract
DNA methylation modulates telomere function. In Arabidopsis thaliana, telomeric regions have a bimodal chromatin organization with unmethylated telomeres and methylated subtelomeres. To gain insight into this organization we have generated TAIR10-Tel, a modified version of the Arabidopsis reference genome with additional sequences at most chromosome ends. TAIR10-Tel has allowed us to analyse DNA methylation at nucleotide resolution level in telomeric regions. We have analysed the wild-type strain and mutants that encode inactive versions of all currently known relevant methyltransferases involved in cytosine methylation. These analyses have revealed that subtelomeric DNA methylation extends 1 to 2 kbp from Interstitial Telomeric Sequences (ITSs) that abut or are very near to telomeres. However, DNA methylation drops at the telomeric side of the telomere-subtelomere boundaries and disappears at the inner part of telomeres. We present a comprehensive and integrative model for subtelomeric DNA methylation that should help to decipher the mechanisms that govern the epigenetic regulation of telomeres. This model involves a complex network of interactions between methyltransferases and subtelomeric DNA sequences.
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Affiliation(s)
- Colin Farrell
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, CA90095, USA
| | - María I Vaquero-Sedas
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC-Universidad de Sevilla, IBVF (CSIC-US), Seville, E41092, Spain
| | - María D Cubiles
- Departamento de Estadística e Investigación Operativa, Facultad de Matemáticas, Universidad de Sevilla, Seville, E41012, Spain
| | - Michael Thompson
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, CA90095, USA
| | - Alejandro Vega-Vaquero
- Escuela Técnica Superior de Ingeniería Informática, Universidad de Sevilla, Seville, E41012, Spain
| | - Matteo Pellegrini
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, CA90095, USA.,Institute of Genomics and Proteomics, Los Angeles, CA90095, USA
| | - Miguel A Vega-Palas
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC-Universidad de Sevilla, IBVF (CSIC-US), Seville, E41092, Spain
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5
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D'Amico-Willman KM, Anderson ES, Gradziel TM, Fresnedo-Ramírez J. Relative Telomere Length and Telomerase Reverse Transcriptase (TERT) Expression Are Associated with Age in Almond ( Prunus dulcis [Mill.] D.A.Webb). PLANTS (BASEL, SWITZERLAND) 2021; 10:189. [PMID: 33498228 PMCID: PMC7909263 DOI: 10.3390/plants10020189] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 01/15/2021] [Accepted: 01/18/2021] [Indexed: 01/02/2023]
Abstract
While all organisms age, our understanding of how aging occurs varies among species. The aging process in perennial plants is not well-defined, yet can have implications on production and yield of valuable fruit and nut crops. Almond exhibits an age-related disorder known as non-infectious bud failure (BF) that affects vegetative bud development, indirectly affecting kernel yield. This species and disorder present an opportunity to address aging in a commercially relevant and vegetatively propagated perennial crop. The hypothesis tested in this study was that relative telomere length and/or telomerase reverse transcriptase (TERT) expression can serve as biomarkers of aging in almond. Relative telomere lengths and expression of TERT, a subunit of the enzyme telomerase, were measured via qPCR methods using bud and leaf samples collected from distinct age cohorts over a two-year period. Results from this work show a marginal but significant association between both relative telomere length and TERT expression, and age, suggesting that as almonds age, telomeres shorten and TERT expression decreases. This work provides information on potential biomarkers of perennial plant aging, contributing to our knowledge of this process. In addition, these results provide opportunities to address BF in almond breeding and nursery propagation.
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Affiliation(s)
- Katherine M. D'Amico-Willman
- Department of Horticulture and Crop Science, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, OH 446911, USA;
- Center for Applied Plant Sciences, The Ohio State University, Columbus, OH 432102, USA
| | | | - Thomas M. Gradziel
- Department of Plant Sciences, University of California, Davis, CA 95616, USA;
| | - Jonathan Fresnedo-Ramírez
- Department of Horticulture and Crop Science, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, OH 446911, USA;
- Center for Applied Plant Sciences, The Ohio State University, Columbus, OH 432102, USA
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6
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Konečná K, Sováková PP, Anteková K, Fajkus J, Fojtová M. Distinct Responses of Arabidopsis Telomeres and Transposable Elements to Zebularine Exposure. Int J Mol Sci 2021; 22:ijms22010468. [PMID: 33466545 PMCID: PMC7796508 DOI: 10.3390/ijms22010468] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 12/21/2020] [Accepted: 12/28/2020] [Indexed: 12/17/2022] Open
Abstract
Involvement of epigenetic mechanisms in the regulation of telomeres and transposable elements (TEs), genomic regions with the protective and potentially detrimental function, respectively, has been frequently studied. Here, we analyzed telomere lengths in Arabidopsis thaliana plants of Columbia, Landsberg erecta and Wassilevskija ecotypes exposed repeatedly to the hypomethylation drug zebularine during germination. Shorter telomeres were detected in plants growing from seedlings germinated in the presence of zebularine with a progression in telomeric phenotype across generations, relatively high inter-individual variability, and diverse responses among ecotypes. Interestingly, the extent of telomere shortening in zebularine Columbia and Wassilevskija plants corresponded to the transcriptional activation of TEs, suggesting a correlated response of these genomic elements to the zebularine treatment. Changes in lengths of telomeres and levels of TE transcripts in leaves were not always correlated with a hypomethylation of cytosines located in these regions, indicating a cytosine methylation-independent level of their regulation. These observations, including differences among ecotypes together with distinct dynamics of the reversal of the disruption of telomere homeostasis and TEs transcriptional activation, reflect a complex involvement of epigenetic processes in the regulation of crucial genomic regions. Our results further demonstrate the ability of plant cells to cope with these changes without a critical loss of the genome stability.
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Affiliation(s)
- Klára Konečná
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute for Technology (CEITEC), Masaryk University, Kamenice 5, CZ-62500 Brno, Czech Republic; (K.K.); (P.P.S.); (K.A.); (J.F.)
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kotlářská 2, CZ-61137 Brno, Czech Republic
| | - Pavla Polanská Sováková
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute for Technology (CEITEC), Masaryk University, Kamenice 5, CZ-62500 Brno, Czech Republic; (K.K.); (P.P.S.); (K.A.); (J.F.)
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kotlářská 2, CZ-61137 Brno, Czech Republic
| | - Karin Anteková
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute for Technology (CEITEC), Masaryk University, Kamenice 5, CZ-62500 Brno, Czech Republic; (K.K.); (P.P.S.); (K.A.); (J.F.)
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kotlářská 2, CZ-61137 Brno, Czech Republic
| | - Jiří Fajkus
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute for Technology (CEITEC), Masaryk University, Kamenice 5, CZ-62500 Brno, Czech Republic; (K.K.); (P.P.S.); (K.A.); (J.F.)
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kotlářská 2, CZ-61137 Brno, Czech Republic
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, CZ-61265 Brno, Czech Republic
| | - Miloslava Fojtová
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute for Technology (CEITEC), Masaryk University, Kamenice 5, CZ-62500 Brno, Czech Republic; (K.K.); (P.P.S.); (K.A.); (J.F.)
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kotlářská 2, CZ-61137 Brno, Czech Republic
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, CZ-61265 Brno, Czech Republic
- Correspondence: ; Tel.: +420-54949-8063
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Aguilar M, Prieto P. Telomeres and Subtelomeres Dynamics in the Context of Early Chromosome Interactions During Meiosis and Their Implications in Plant Breeding. FRONTIERS IN PLANT SCIENCE 2021; 12:672489. [PMID: 34149773 PMCID: PMC8212018 DOI: 10.3389/fpls.2021.672489] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 05/06/2021] [Indexed: 05/08/2023]
Abstract
Genomic architecture facilitates chromosome recognition, pairing, and recombination. Telomeres and subtelomeres play an important role at the beginning of meiosis in specific chromosome recognition and pairing, which are critical processes that allow chromosome recombination between homologs (equivalent chromosomes in the same genome) in later stages. In plant polyploids, these terminal regions are even more important in terms of homologous chromosome recognition, due to the presence of homoeologs (equivalent chromosomes from related genomes). Although telomeres interaction seems to assist homologous pairing and consequently, the progression of meiosis, other chromosome regions, such as subtelomeres, need to be considered, because the DNA sequence of telomeres is not chromosome-specific. In addition, recombination operates at subtelomeres and, as it happens in rye and wheat, homologous recognition and pairing is more often correlated with recombining regions than with crossover-poor regions. In a plant breeding context, the knowledge of how homologous chromosomes initiate pairing at the beginning of meiosis can contribute to chromosome manipulation in hybrids or interspecific genetic crosses. Thus, recombination in interspecific chromosome associations could be promoted with the aim of transferring desirable agronomic traits from related genetic donor species into crops. In this review, we summarize the importance of telomeres and subtelomeres on chromatin dynamics during early meiosis stages and their implications in recombination in a plant breeding framework.
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Affiliation(s)
- Miguel Aguilar
- Área de Fisiología Vegetal, Universidad de Córdoba, Córdoba, Spain
| | - Pilar Prieto
- Plant Breeding Department, Institute for Sustainable Agriculture, Agencia Estatal Consejo Superior de Investigaciones Científicas (CSIC), Córdoba, Spain
- *Correspondence: Pilar Prieto, ; orcid.org/0000-0002-8160-808X
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Školáková P, Badri Z, Foldynová-Trantírková S, Ryneš J, Šponer J, Fojtová M, Fajkus J, Marek R, Vorlíčková M, Mergny JL, Trantírek L. Composite 5-methylations of cytosines modulate i-motif stability in a sequence-specific manner: Implications for DNA nanotechnology and epigenetic regulation of plant telomeric DNA. Biochim Biophys Acta Gen Subj 2020; 1864:129651. [DOI: 10.1016/j.bbagen.2020.129651] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 05/23/2020] [Accepted: 05/28/2020] [Indexed: 12/14/2022]
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Achrem M, Szućko I, Kalinka A. The epigenetic regulation of centromeres and telomeres in plants and animals. COMPARATIVE CYTOGENETICS 2020; 14:265-311. [PMID: 32733650 PMCID: PMC7360632 DOI: 10.3897/compcytogen.v14i2.51895] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 05/18/2020] [Indexed: 05/10/2023]
Abstract
The centromere is a chromosomal region where the kinetochore is formed, which is the attachment point of spindle fibers. Thus, it is responsible for the correct chromosome segregation during cell division. Telomeres protect chromosome ends against enzymatic degradation and fusions, and localize chromosomes in the cell nucleus. For this reason, centromeres and telomeres are parts of each linear chromosome that are necessary for their proper functioning. More and more research results show that the identity and functions of these chromosomal regions are epigenetically determined. Telomeres and centromeres are both usually described as highly condensed heterochromatin regions. However, the epigenetic nature of centromeres and telomeres is unique, as epigenetic modifications characteristic of both eu- and heterochromatin have been found in these areas. This specificity allows for the proper functioning of both regions, thereby affecting chromosome homeostasis. This review focuses on demonstrating the role of epigenetic mechanisms in the functioning of centromeres and telomeres in plants and animals.
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Affiliation(s)
- Magdalena Achrem
- Institute of Biology, University of Szczecin, Szczecin, PolandUniversity of SzczecinSzczecinPoland
- Molecular Biology and Biotechnology Center, University of Szczecin, Szczecin, PolandUniversity of SzczecinSzczecinPoland
| | - Izabela Szućko
- Institute of Biology, University of Szczecin, Szczecin, PolandUniversity of SzczecinSzczecinPoland
- Molecular Biology and Biotechnology Center, University of Szczecin, Szczecin, PolandUniversity of SzczecinSzczecinPoland
| | - Anna Kalinka
- Institute of Biology, University of Szczecin, Szczecin, PolandUniversity of SzczecinSzczecinPoland
- Molecular Biology and Biotechnology Center, University of Szczecin, Szczecin, PolandUniversity of SzczecinSzczecinPoland
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10
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Telomeres in Plants and Humans: Not So Different, Not So Similar. Cells 2019; 8:cells8010058. [PMID: 30654521 PMCID: PMC6356271 DOI: 10.3390/cells8010058] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 01/07/2019] [Accepted: 01/07/2019] [Indexed: 01/01/2023] Open
Abstract
Parallel research on multiple model organisms shows that while some principles of telomere biology are conserved among all eukaryotic kingdoms, we also find some deviations that reflect different evolutionary paths and life strategies, which may have diversified after the establishment of telomerase as a primary mechanism for telomere maintenance. Much more than animals, plants have to cope with environmental stressors, including genotoxic factors, due to their sessile lifestyle. This is, in principle, made possible by an increased capacity and efficiency of the molecular systems ensuring maintenance of genome stability, as well as a higher tolerance to genome instability. Furthermore, plant ontogenesis differs from that of animals in which tissue differentiation and telomerase silencing occur during early embryonic development, and the “telomere clock” in somatic cells may act as a preventive measure against carcinogenesis. This does not happen in plants, where growth and ontogenesis occur through the serial division of apical meristems consisting of a small group of stem cells that generate a linear series of cells, which differentiate into an array of cell types that make a shoot and root. Flowers, as generative plant organs, initiate from the shoot apical meristem in mature plants which is incompatible with the human-like developmental telomere shortening. In this review, we discuss differences between human and plant telomere biology and the implications for aging, genome stability, and cell and organism survival. In particular, we provide a comprehensive comparative overview of telomere proteins acting in humans and in Arabidopsis thaliana model plant, and discuss distinct epigenetic features of telomeric chromatin in these species.
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11
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Sováková PP, Magdolenová A, Konečná K, Rájecká V, Fajkus J, Fojtová M. Telomere elongation upon transfer to callus culture reflects the reprogramming of telomere stability control in Arabidopsis. PLANT MOLECULAR BIOLOGY 2018; 98:81-99. [PMID: 30128721 DOI: 10.1007/s11103-018-0765-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 08/12/2018] [Indexed: 05/23/2023]
Abstract
KEY MESSAGE Standard pathways involved in the regulation of telomere stability do not contribute to gradual telomere elongation observed in the course of A. thaliana calli propagation. Genetic and epigenetic changes accompanying the culturing of plant cells have frequently been reported. Here we aimed to characterize the telomere homeostasis during long term callus propagation. While in Arabidopsis thaliana calli gradual telomere elongation was observed, telomeres were stable in Nicotiana tabacum and N. sylvestris cultures. Telomere elongation during callus propagation is thus not a general feature of plant cells. The long telomere phenotype in Arabidopsis calli was correlated neither with changes in telomerase activity nor with activation of alternative mechanisms of telomere elongation. The dynamics of telomere length changes was maintained in mutant calli with loss of function of important epigenetic modifiers but compromised in the presence of epigenetically active drug zebularine. To examine whether the cell culture-induced disruption of telomere homeostasis is associated with the modulated structure of chromosome ends, epigenetic properties of telomere chromatin were analysed. Albeit distinct changes in epigenetic modifications of telomere histones were observed, these were broadly stochastic. Our results show that contrary to animal cells, the structure and function of plant telomeres is not determined significantly by the epigenetic character of telomere chromatin. Set of differentially transcribed genes was identified in calli, but considering the known telomere- or telomerase-related functions of respective proteins, none of these changes per se was apparently related to the elongated telomere phenotype. Based on our data, we propose that the disruption in telomere homeostasis in Arabidopsis calli arises from the interplay of multiple factors, as a part of reprogramming of plant cells to long-term culture conditions.
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Affiliation(s)
- Pavla Polanská Sováková
- Laboratory of Functional Genomics and Proteomics, Faculty of Science, National Centre for Biomolecular Research, Masaryk University, 625 00, Brno, Czech Republic
| | - Alžbeta Magdolenová
- Laboratory of Functional Genomics and Proteomics, Faculty of Science, National Centre for Biomolecular Research, Masaryk University, 625 00, Brno, Czech Republic
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic v.v.i., Prague, Czech Republic
| | - Klára Konečná
- Laboratory of Functional Genomics and Proteomics, Faculty of Science, National Centre for Biomolecular Research, Masaryk University, 625 00, Brno, Czech Republic
| | - Veronika Rájecká
- Laboratory of Functional Genomics and Proteomics, Faculty of Science, National Centre for Biomolecular Research, Masaryk University, 625 00, Brno, Czech Republic
| | - Jiří Fajkus
- Laboratory of Functional Genomics and Proteomics, Faculty of Science, National Centre for Biomolecular Research, Masaryk University, 625 00, Brno, Czech Republic
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology (CEITEC), Masaryk University, 625 00, Brno, Czech Republic
- Institute of Biophysics, Academy of Sciences of the Czech Republic v.v.i., 612 65, Brno, Czech Republic
| | - Miloslava Fojtová
- Laboratory of Functional Genomics and Proteomics, Faculty of Science, National Centre for Biomolecular Research, Masaryk University, 625 00, Brno, Czech Republic.
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology (CEITEC), Masaryk University, 625 00, Brno, Czech Republic.
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12
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Xie X, Shippen DE. DDM1 guards against telomere truncation in Arabidopsis. PLANT CELL REPORTS 2018; 37:501-513. [PMID: 29392401 PMCID: PMC5880217 DOI: 10.1007/s00299-017-2245-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Accepted: 12/26/2017] [Indexed: 05/20/2023]
Abstract
Prolonged hypomethylation of DNA leads to telomere truncation correlated with increased telomere recombination, transposon mobilization and stem cell death. Epigenetic pathways, including DNA methylation, are crucial for telomere maintenance. Deficient in DNA Methylation 1 (DDM1) encodes a nucleosome remodeling protein, required to maintain DNA methylation in Arabidopsis thaliana. Plants lacking DDM1 can be self-propagated, but in the sixth generation (G6) hypomethylation leads to rampant transposon activation and infertility. Here we examine the role of DDM1 in telomere length homeostasis through a longitudinal study of successive generations of ddm1-2 mutants. We report that bulk telomere length remains within the wild-type range for the first five generations (G1-G5), and then precipitously drops in G6. While telomerase activity becomes more variable in later generation ddm1-2 mutants, there is no correlation between enzyme activity and telomere length. Plants lacking DDM1 also exhibit no dysregulation of several known telomere-associated transcripts, including TERRA. Instead, telomere shortening coincides with increased G-overhangs and extra-chromosomal circles, consistent with deletional recombination. Telomere shortening also correlates with transcriptional activation of retrotransposons, and a hypersensitive DNA damage response in root apical meristems. Since abiotic stresses, including DNA damage, stimulate homologous recombination, we hypothesize that telomere deletion in G6 ddm1-2 mutants is a by-product of elevated genome-wide recombination in response to transposon mobilization. Further, we speculate that telomere truncation may be beneficial in adverse environmental conditions by accelerating the elimination of stem cells with aberrant genomes.
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Affiliation(s)
- Xiaoyuan Xie
- Department of Biochemistry and Biophysics, Texas A&M University, 2128 TAMU, College Station, TX, 77843-2128, USA
| | - Dorothy E Shippen
- Department of Biochemistry and Biophysics, Texas A&M University, 2128 TAMU, College Station, TX, 77843-2128, USA.
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13
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Vega-Vaquero A, Bonora G, Morselli M, Vaquero-Sedas MI, Rubbi L, Pellegrini M, Vega-Palas MA. Novel features of telomere biology revealed by the absence of telomeric DNA methylation. Genome Res 2016; 26:1047-56. [PMID: 27405804 PMCID: PMC4971770 DOI: 10.1101/gr.202465.115] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Accepted: 06/20/2016] [Indexed: 12/21/2022]
Abstract
Cytosine methylation regulates the length and stability of telomeres, which can affect a wide variety of biological features, including cell differentiation, development, or illness. Although it is well established that subtelomeric regions are methylated, the presence of methylated cytosines at telomeres has remained controversial. Here, we have analyzed multiple bisulfite sequencing studies to address the methylation status of Arabidopsis thaliana telomeres. We found that the levels of estimated telomeric DNA methylation varied among studies. Interestingly, we estimated higher levels of telomeric DNA methylation in studies that produced C-rich telomeric strands with lower efficiency. However, these high methylation estimates arose due to experimental limitations of the bisulfite technique. We found a similar phenomenon for mitochondrial DNA: The levels of mitochondrial DNA methylation detected were higher in experiments with lower mitochondrial read production efficiencies. Based on experiments with high telomeric C-rich strand production efficiencies, we concluded that Arabidopsis telomeres are not methylated, which was confirmed by methylation-dependent restriction enzyme analyses. Thus, our studies indicate that telomeres are refractory to de novo DNA methylation by the RNA-directed DNA methylation machinery. This result, together with previously reported data, reveals that subtelomeric DNA methylation controls the homeostasis of telomere length.
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Affiliation(s)
- Alejandro Vega-Vaquero
- Technical Superior School of Informatics Engineering, University of Seville, 41080 Seville, Spain
| | - Giancarlo Bonora
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, California 90095, USA
| | - Marco Morselli
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, California 90095, USA
| | - María I Vaquero-Sedas
- Institute of Vegetal Biochemistry and Photosynthesis, CSIC-University of Seville, IBVF (CSIC-US), 41092 Seville, Spain
| | - Liudmilla Rubbi
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, California 90095, USA
| | - Matteo Pellegrini
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, California 90095, USA
| | - Miguel A Vega-Palas
- Institute of Vegetal Biochemistry and Photosynthesis, CSIC-University of Seville, IBVF (CSIC-US), 41092 Seville, Spain
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14
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Dvořáčková M, Fojtová M, Fajkus J. Chromatin dynamics of plant telomeres and ribosomal genes. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2015; 83:18-37. [PMID: 25752316 DOI: 10.1111/tpj.12822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Revised: 03/03/2015] [Accepted: 03/03/2015] [Indexed: 05/03/2023]
Abstract
Telomeres and genes encoding 45S ribosomal RNA (rDNA) are frequently located adjacent to each other on eukaryotic chromosomes. Although their primary roles are different, they show striking similarities with respect to their features and additional functions. Both genome domains have remarkably dynamic chromatin structures. Both are hypersensitive to dysfunctional histone chaperones, responding at the genomic and epigenomic levels. Both generate non-coding transcripts that, in addition to their epigenetic roles, may induce gross chromosomal rearrangements. Both give rise to chromosomal fragile sites, as their replication is intrinsically problematic. However, at the same time, both are essential for maintenance of genomic stability and integrity. Here we discuss the structural and functional inter-connectivity of telomeres and rDNA, with a focus on recent results obtained in plants.
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Affiliation(s)
- Martina Dvořáčková
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Kamenice 5, 62500, Brno, Czech Republic
- Faculty of Science, Masaryk University, Kamenice 5, 62500, Brno, Czech Republic
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 61265, Brno, Czech Republic
| | - Miloslava Fojtová
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Kamenice 5, 62500, Brno, Czech Republic
- Faculty of Science, Masaryk University, Kamenice 5, 62500, Brno, Czech Republic
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 61265, Brno, Czech Republic
| | - Jiří Fajkus
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Kamenice 5, 62500, Brno, Czech Republic
- Faculty of Science, Masaryk University, Kamenice 5, 62500, Brno, Czech Republic
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 61265, Brno, Czech Republic
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15
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Vaquero-Sedas MI, Vega-Palas MA. Determination of Arabidopsis thaliana telomere length by PCR. Sci Rep 2014; 4:5540. [PMID: 24986269 PMCID: PMC4078305 DOI: 10.1038/srep05540] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Accepted: 06/16/2014] [Indexed: 11/28/2022] Open
Abstract
In humans, telomere length studies have acquired great relevance because the length of telomeres has been related to natural processes like disease, aging and cancer. However, very little is known about the influence of telomere length on the biology of wild type plants. The length of plant telomeres has been usually studied by Terminal Restriction Fragment (TRF) analyses. This technique requires high amounts of tissue, including multiple cell types, which might be the reason why very little is known about the influence of telomere length on plant natural processes. In contrast, many of the human telomere length studies have focused on homogenous cell populations. Most of these studies have been performed by PCR, using telomeric degenerated primers, which allow the determination of telomere length from small amounts of human cells. Here, we have adapted the human PCR procedure to analyze the length of Arabidopsis thaliana telomeres. This PCR approach will facilitate the analysis of telomere length from low amounts of tissue. We have used it to determine that CG and non CG DNA methylation positively regulates Arabidopsis telomere length.
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Affiliation(s)
- María I. Vaquero-Sedas
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC-Universidad de Sevilla, IBVF (CSIC-US), c/Américo Vespucio n° 49, 41092 Seville, Spain
| | - Miguel A. Vega-Palas
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC-Universidad de Sevilla, IBVF (CSIC-US), c/Américo Vespucio n° 49, 41092 Seville, Spain
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16
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Del Prete S, Arpón J, Sakai K, Andrey P, Gaudin V. Nuclear architecture and chromatin dynamics in interphase nuclei of Arabidopsis thaliana. Cytogenet Genome Res 2014; 143:28-50. [PMID: 24992956 DOI: 10.1159/000363724] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The interphase cell nucleus is extraordinarily complex, ordered, and dynamic. In the last decade, remarkable progress has been made in deciphering the functional organisation of the cell nucleus, and intricate relationships between genome functions (transcription, DNA repair, or replication) and various nuclear compartments have been revealed. In this review, we describe the architecture of the Arabidopsis thaliana interphase cell nucleus and discuss the dynamic nature of its organisation. We underline the need for further developments in quantitative and modelling approaches to nuclear organization.
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Affiliation(s)
- Stefania Del Prete
- INRA, UMR1318-AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), INRA-Centre de Versailles-Grignon, Versailles, France
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17
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Fojtová M, Fajkus J. Epigenetic Regulation of Telomere Maintenance. Cytogenet Genome Res 2014; 143:125-35. [DOI: 10.1159/000360775] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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18
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Abstract
By incorporating annotation information into the analysis of next-generation sequencing DNA methylation data, we provide an improvement in performance over current testing procedures. Methylation analysis using genome information (MAGI) is applicable for both unreplicated and replicated data, and provides an effective analysis for studies with low sequencing depth. When compared with current tests, the annotation-informed tests provide an increase in statistical power and offer a significance-based interpretation of differential methylation.
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Affiliation(s)
- Douglas D Baumann
- Department of Mathematics; University of Wisconsin, La Crosse; La Crosse, WI USA
| | - R W Doerge
- Department of Statistics; Purdue University; West Lafayette, IN USA
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19
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Jarillo JA, Gaudin V, Hennig L, Köhler C, Piñeiro M. Plant chromatin warms up in Madrid: meeting summary of the 3rd European Workshop on Plant Chromatin 2013, Madrid, Spain. Epigenetics 2014; 9:644-52. [PMID: 24504145 DOI: 10.4161/epi.28094] [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] [Indexed: 11/19/2022] Open
Abstract
The 3rd European Workshop on Plant Chromatin (EWPC) was held on August 2013 in Madrid, Spain. A number of different topics on plant chromatin were presented during the meeting, including new factors mediating Polycomb Group protein function in plants, chromatin-mediated reprogramming in plant developmental transitions, the role of histone variants, and newly identified chromatin remodeling factors. The function of interactions between chromatin and transcription factors in the modulation of gene expression, the role of chromatin dynamics in the control of nuclear processes and the influence of environmental factors on chromatin organization were also reported. In this report, we highlight some of the new insights emerging in this growing area of research, presented at the 3rd EWPC.
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Affiliation(s)
- José A Jarillo
- Centro de Biotecnología y Genómica de Plantas (CBGP), INIA-UPM; INIA, Campus de Montegancedo; Madrid, Spain
| | - Valérie Gaudin
- NRA; AgroParis Tech; UMR1318; Insitut Jean Pierre Bourgin; Versailles, France
| | - Lars Hennig
- Swedish University of Agricultural Sciences; Uppsala BioCenter; Uppsala, Sweden
| | - Claudia Köhler
- Swedish University of Agricultural Sciences; Uppsala BioCenter; Uppsala, Sweden
| | - Manuel Piñeiro
- Centro de Biotecnología y Genómica de Plantas (CBGP), INIA-UPM; INIA, Campus de Montegancedo; Madrid, Spain
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20
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Majerová E, Mandáková T, Vu GTH, Fajkus J, Lysak MA, Fojtová M. Chromatin features of plant telomeric sequences at terminal vs. internal positions. FRONTIERS IN PLANT SCIENCE 2014; 5:593. [PMID: 25408695 PMCID: PMC4219495 DOI: 10.3389/fpls.2014.00593] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Accepted: 10/11/2014] [Indexed: 05/19/2023]
Abstract
Epigenetic mechanisms are involved in regulation of crucial cellular processes in eukaryotic organisms. Data on the epigenetic features of plant telomeres and their epigenetic regulation were published mostly for Arabidopsis thaliana, in which the presence of interstitial telomeric repeats (ITRs) may interfere with genuine telomeres in most analyses. Here, we studied the epigenetic landscape and transcription of telomeres and ITRs in Nicotiana tabacum with long telomeres and no detectable ITRs, and in Ballantinia antipoda with large blocks of pericentromeric ITRs and relatively short telomeres. Chromatin of genuine telomeres displayed heterochromatic as well as euchromatic marks, while ITRs were just heterochromatic. Methylated cytosines were present at telomeres and ITRs, but showed a bias with more methylation toward distal telomere positions and different blocks of B. antipoda ITRs methylated to different levels. Telomeric transcripts TERRA (G-rich) and ARRET (C-rich) were identified in both plants and their levels varied among tissues with a maximum in blossoms. Plants with substantially different proportions of internally and terminally located telomeric repeats are instrumental in clarifying the chromatin status of telomeric repeats at distinct chromosome locations.
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Affiliation(s)
- Eva Majerová
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology and Faculty of Science, Masaryk UniversityBrno, Czech Republic
| | - Terezie Mandáková
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology and Faculty of Science, Masaryk UniversityBrno, Czech Republic
| | - Giang T. H. Vu
- Max Planck Institute for Plant Breeding ResearchCologne, Germany
| | - Jiří Fajkus
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology and Faculty of Science, Masaryk UniversityBrno, Czech Republic
- Institute of Biophysics, Academy of Sciences of the Czech Republic v.v.i.Brno, Czech Republic
| | - Martin A. Lysak
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology and Faculty of Science, Masaryk UniversityBrno, Czech Republic
| | - Miloslava Fojtová
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology and Faculty of Science, Masaryk UniversityBrno, Czech Republic
- *Correspondence: Miloslava Fojtová, Central European Institute of Technology and Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic e-mail:
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