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Kakoulidou I, Piecyk RS, Meyer RC, Kuhlmann M, Gutjahr C, Altmann T, Johannes F. Mapping parental DMRs predictive of local and distal methylome remodeling in epigenetic F1 hybrids. Life Sci Alliance 2024; 7:e202402599. [PMID: 38290756 PMCID: PMC10828516 DOI: 10.26508/lsa.202402599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 01/21/2024] [Accepted: 01/22/2024] [Indexed: 02/01/2024] Open
Abstract
F1 hybrids derived from a cross between two inbred parental lines often display widespread changes in DNA methylation and gene expression patterns relative to their parents. An emerging challenge is to understand how parental epigenomic differences contribute to these events. Here, we generated a large mapping panel of F1 epigenetic hybrids, whose parents are isogenic but variable in their DNA methylation patterns. Using a combination of multi-omic profiling and epigenetic mapping strategies we show that differentially methylated regions in parental pericentromeres act as major reorganizers of hybrid methylomes and transcriptomes, even in the absence of genetic variation. These parental differentially methylated regions are associated with hybrid methylation remodeling events at thousands of target regions throughout the genome, both locally (in cis) and distally (in trans). Many of these distally-induced methylation changes lead to nonadditive expression of nearby genes and associate with phenotypic heterosis. Our study highlights the pleiotropic potential of parental pericentromeres in the functional remodeling of hybrid genomes and phenotypes.
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Affiliation(s)
- Ioanna Kakoulidou
- https://ror.org/02kkvpp62 Plant Epigenomics, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Munich, Germany
| | - Robert S Piecyk
- https://ror.org/02kkvpp62 Plant Epigenomics, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Munich, Germany
| | - Rhonda C Meyer
- https://ror.org/02skbsp27 Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, Germany
| | - Markus Kuhlmann
- https://ror.org/02skbsp27 Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, Germany
| | - Caroline Gutjahr
- Plant Genetics, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
| | - Thomas Altmann
- https://ror.org/02skbsp27 Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, Germany
| | - Frank Johannes
- https://ror.org/02kkvpp62 Plant Epigenomics, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Munich, Germany
- https://ror.org/02kkvpp62 Institute of Advanced Studies, Technical University of Munich, Munich, Germany
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2
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Yuditskiy K, Bezdvornykh I, Kazantseva A, Kanapin A, Samsonova A. BSXplorer: analytical framework for exploratory analysis of BS-seq data. BMC Bioinformatics 2024; 25:96. [PMID: 38438881 PMCID: PMC10913661 DOI: 10.1186/s12859-024-05722-9] [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: 11/16/2023] [Accepted: 02/27/2024] [Indexed: 03/06/2024] Open
Abstract
BACKGROUND Bisulfite sequencing detects and quantifies DNA methylation patterns, contributing to our understanding of gene expression regulation, genome stability maintenance, conservation of epigenetic mechanisms across divergent taxa, epigenetic inheritance and, eventually, phenotypic variation. Graphical representation of methylation data is crucial in exploring epigenetic regulation on a genome-wide scale in both plants and animals. This is especially relevant for non-model organisms with poorly annotated genomes and/or organisms where genome sequences are not yet assembled on chromosome level. Despite being a technology of choice to profile DNA methylation for many years now there are surprisingly few lightweight and robust standalone tools available for efficient graphical analysis of data in non-model systems. This significantly limits evolutionary studies and agrigenomics research. BSXplorer is a tool specifically developed to fill this gap and assist researchers in explorative data analysis and in visualising and interpreting bisulfite sequencing data more easily. RESULTS BSXplorer provides in-depth graphical analysis of sequencing data encompassing (a) profiling of methylation levels in metagenes or in user-defined regions using line plots and heatmaps, generation of summary statistics charts, (b) enabling comparative analyses of methylation patterns across experimental samples, methylation contexts and species, and (c) identification of modules sharing similar methylation signatures at functional genomic elements. The tool processes methylation data quickly and offers API and CLI capabilities, along with the ability to create high-quality figures suitable for publication. CONCLUSIONS BSXplorer facilitates efficient methylation data mining, contrasting and visualization, making it an easy-to-use package that is highly useful for epigenetic research.
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Affiliation(s)
- Konstantin Yuditskiy
- Institute of Translational Biomedicine, Saint Petersburg State University, Saint Petersburg, Russia, 199004
| | - Igor Bezdvornykh
- Institute of Translational Biomedicine, Saint Petersburg State University, Saint Petersburg, Russia, 199004
| | - Anastasiya Kazantseva
- Laboratory of Neurocognitive Genomics, Department of Genetics and Fundamental Medicine, Ufa University of Science and Technology, Ufa, Russia, 450076
| | - Alexander Kanapin
- Institute of Translational Biomedicine, Saint Petersburg State University, Saint Petersburg, Russia, 199004
| | - Anastasia Samsonova
- Institute of Translational Biomedicine, Saint Petersburg State University, Saint Petersburg, Russia, 199004.
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3
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Webster AK, Phillips PC. Heritable epigenetic variation facilitates long-term maintenance of epigenetic and genetic variation. G3 (BETHESDA, MD.) 2024; 14:jkad287. [PMID: 38113034 PMCID: PMC10849368 DOI: 10.1093/g3journal/jkad287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 08/03/2023] [Accepted: 11/22/2023] [Indexed: 12/21/2023]
Abstract
How genetic and phenotypic variation are maintained has long been one of the fundamental questions in population and quantitative genetics. A variety of factors have been implicated to explain the maintenance of genetic variation in some contexts (e.g. balancing selection), but the potential role of epigenetic regulation to influence population dynamics has been understudied. It is well recognized that epigenetic regulation, including histone methylation, small RNA expression, and DNA methylation, helps to define differences between cell types and facilitate phenotypic plasticity. In recent years, empirical studies have shown the potential for epigenetic regulation to also be heritable for at least a few generations without selection, raising the possibility that differences in epigenetic regulation can act alongside genetic variation to shape evolutionary trajectories. Heritable differences in epigenetic regulation that arise spontaneously are termed "epimutations." Epimutations differ from genetic mutations in 2 key ways-they occur at a higher rate and the loci at which they occur often revert back to their original state within a few generations. Here, we present an extension of the standard population genetic model with selection to incorporate epigenetic variation arising via epimutation. Our model assumes a diploid, sexually reproducing population with random mating. In addition to spontaneous genetic mutation, we included parameters for spontaneous epimutation and back-epimutation, allowing for 4 potential epialleles at a single locus (2 genetic alleles, each with 2 epigenetic states), each of which affect fitness. We then analyzed the conditions under which stable epialleles were maintained. Our results show that highly reversible epialleles can be maintained in long-term equilibrium under neutral conditions in a manner that depends on the epimutation and back-epimutation rates, which we term epimutation-back-epimutation equilibrium. On the other hand, epialleles that compensate for deleterious mutations cause deviations from the expectations of mutation-selection balance by a simple factor that depends on the epimutation and back-epimutation rates. We also numerically analyze several sets of fitness parameters for which large deviations from mutation-selection balance occur. Together, these results demonstrate that transient epigenetic regulation may be an important factor in the maintenance of both epigenetic and genetic variation in populations.
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Affiliation(s)
- Amy K Webster
- Institute of Ecology and Evolution, University of Oregon, Eugene, OR 97403, USA
| | - Patrick C Phillips
- Institute of Ecology and Evolution, University of Oregon, Eugene, OR 97403, USA
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4
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Zeng Y, Dawe RK, Gent JI. Natural methylation epialleles correlate with gene expression in maize. Genetics 2023; 225:iyad146. [PMID: 37556604 PMCID: PMC10550312 DOI: 10.1093/genetics/iyad146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 02/22/2023] [Accepted: 07/31/2023] [Indexed: 08/11/2023] Open
Abstract
DNA methylation in plants is depleted from cis-regulatory elements in and near genes but is present in some gene bodies, including exons. Methylation in exons solely in the CG context is called gene body methylation (gbM). Methylation in exons in both CG and non-CG contexts is called TE-like methylation (teM). Assigning functions to both forms of methylation in genes has proven to be challenging. Toward that end, we utilized recent genome assemblies, gene annotations, transcription data, and methylome data to quantify common patterns of gene methylation and their relations to gene expression in maize. We found that gbM genes exist in a continuum of CG methylation levels without a clear demarcation between unmethylated genes and gbM genes. Analysis of expression levels across diverse maize stocks and tissues revealed a weak but highly significant positive correlation between gbM and gene expression except in endosperm. gbM epialleles were associated with an approximately 3% increase in steady-state expression level relative to unmethylated epialleles. In contrast to gbM genes, which were conserved and were broadly expressed across tissues, we found that teM genes, which make up about 12% of genes, are mainly silent, are poorly conserved, and exhibit evidence of annotation errors. We used these data to flag teM genes in the 26 NAM founder genome assemblies. While some teM genes are likely functional, these data suggest that the majority are not, and their inclusion can confound the interpretation of whole-genome studies.
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Affiliation(s)
- Yibing Zeng
- Department of Genetics, University of Georgia, Athens, GA 30602, USA
| | - R Kelly Dawe
- Department of Genetics, University of Georgia, Athens, GA 30602, USA
- Department of Plant Biology, University of Georgia, Athens, GA 30602, USA
| | - Jonathan I Gent
- Department of Plant Biology, University of Georgia, Athens, GA 30602, USA
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5
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Goeldel C, Johannes F. Stochasticity in gene body methylation. CURRENT OPINION IN PLANT BIOLOGY 2023; 75:102436. [PMID: 37597469 DOI: 10.1016/j.pbi.2023.102436] [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: 03/31/2023] [Revised: 06/30/2023] [Accepted: 07/10/2023] [Indexed: 08/21/2023]
Abstract
Gene body methylation (gbM) is a widely conserved epigenetic feature of plant genomes. Efforts to delineate the mechanisms by which gbM contributes to transcriptional regulation remain largely inconclusive, and its evolutionary significance continues to be debated. Curiously, although steady-state gbM levels are remarkably stable across mitotic and meiotic cell divisions, the methylation status of individual CG dinucleotides in gbM genes is highly stochastic. How can these two seemingly contradictory observations be reconciled? Here, we discuss how stochastic processes relate to gbM maintenance dynamics. We show that a quantitative understanding of these processes can shed deeper insights into the molecular and evolutionary biology of this enigmatic epigenetic trait.
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Affiliation(s)
| | - Frank Johannes
- Plant Epigenomics, Technical University of Munich, Germany.
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6
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Yao N, Zhang Z, Yu L, Hazarika R, Yu C, Jang H, Smith LM, Ton J, Liu L, Stachowicz JJ, Reusch TBH, Schmitz RJ, Johannes F. An evolutionary epigenetic clock in plants. Science 2023; 381:1440-1445. [PMID: 37769069 DOI: 10.1126/science.adh9443] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Accepted: 08/08/2023] [Indexed: 09/30/2023]
Abstract
Molecular clocks are the basis for dating the divergence between lineages over macroevolutionary timescales (~105 to 108 years). However, classical DNA-based clocks tick too slowly to inform us about the recent past. Here, we demonstrate that stochastic DNA methylation changes at a subset of cytosines in plant genomes display a clocklike behavior. This "epimutation clock" is orders of magnitude faster than DNA-based clocks and enables phylogenetic explorations on a scale of years to centuries. We show experimentally that epimutation clocks recapitulate known topologies and branching times of intraspecies phylogenetic trees in the self-fertilizing plant Arabidopsis thaliana and the clonal seagrass Zostera marina, which represent two major modes of plant reproduction. This discovery will open new possibilities for high-resolution temporal studies of plant biodiversity.
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Affiliation(s)
- N Yao
- Department of Genetics, University of Georgia, Athens, GA, USA
| | - Z Zhang
- Plant Epigenomics, Technical University of Munich, Freising, Germany
| | - L Yu
- Marine Evolutionary Ecology, GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
| | - R Hazarika
- Plant Epigenomics, Technical University of Munich, Freising, Germany
| | - C Yu
- Plant Epigenomics, Technical University of Munich, Freising, Germany
| | - H Jang
- Department of Genetics, University of Georgia, Athens, GA, USA
| | - L M Smith
- School of Biosciences, University of Sheffield, Sheffield, UK
| | - J Ton
- School of Biosciences, University of Sheffield, Sheffield, UK
| | - L Liu
- Department of Statistics, University of Georgia, Athens, GA, USA
| | - J J Stachowicz
- Department of Evolution and Ecology, University of California, Davis, CA, USA
| | - T B H Reusch
- Marine Evolutionary Ecology, GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
| | - R J Schmitz
- Department of Genetics, University of Georgia, Athens, GA, USA
| | - F Johannes
- Plant Epigenomics, Technical University of Munich, Freising, Germany
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7
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Pisupati R, Nizhynska V, Mollá Morales A, Nordborg M. On the causes of gene-body methylation variation in Arabidopsis thaliana. PLoS Genet 2023; 19:e1010728. [PMID: 37141384 DOI: 10.1371/journal.pgen.1010728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 05/16/2023] [Accepted: 03/31/2023] [Indexed: 05/06/2023] Open
Abstract
Gene-body methylation (gbM) refers to sparse CG methylation of coding regions, which is especially prominent in evolutionarily conserved house-keeping genes. It is found in both plants and animals, but is directly and stably (epigenetically) inherited over multiple generations in the former. Studies in Arabidopsis thaliana have demonstrated that plants originating from different parts of the world exhibit genome-wide differences in gbM, which could reflect direct selection on gbM, but which could also reflect an epigenetic memory of ancestral genetic and/or environmental factors. Here we look for evidence of such factors in F2 plants resulting from a cross between a southern Swedish line with low gbM and a northern Swedish line with high gbM, grown at two different temperatures. Using bisulfite-sequencing data with nucleotide-level resolution on hundreds of individuals, we confirm that CG sites are either methylated (nearly 100% methylation across sampled cells) or unmethylated (approximately 0% methylation across sampled cells), and show that the higher level of gbM in the northern line is due to more sites being methylated. Furthermore, methylation variants almost always show Mendelian segregation, consistent with their being directly and stably inherited through meiosis. To explore how the differences between the parental lines could have arisen, we focused on somatic deviations from the inherited state, distinguishing between gains (relative to the inherited 0% methylation) and losses (relative to the inherited 100% methylation) at each site in the F2 generation. We demonstrate that deviations predominantly affect sites that differ between the parental lines, consistent with these sites being more mutable. Gains and losses behave very differently in terms of the genomic distribution, and are influenced by the local chromatin state. We find clear evidence for different trans-acting genetic polymorphism affecting gains and losses, with those affecting gains showing strong environmental interactions (G×E). Direct effects of the environment were minimal. In conclusion, we show that genetic and environmental factors can change gbM at a cellular level, and hypothesize that these factors can also lead to transgenerational differences between individuals via the inclusion of such changes in the zygote. If true, this could explain genographic pattern of gbM with selection, and would cast doubt on estimates of epimutation rates from inbred lines in constant environments.
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Affiliation(s)
- Rahul Pisupati
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter (VBC), Vienna, Austria
- Vienna Graduate School of Population Genetics, Institut für Populationsgenetik, Vetmeduni, Vienna, Austria
| | - Viktoria Nizhynska
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter (VBC), Vienna, Austria
| | - Almudena Mollá Morales
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter (VBC), Vienna, Austria
| | - Magnus Nordborg
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter (VBC), Vienna, Austria
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8
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Epigenetic Changes Occurring in Plant Inbreeding. Int J Mol Sci 2023; 24:ijms24065407. [PMID: 36982483 PMCID: PMC10048984 DOI: 10.3390/ijms24065407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 03/01/2023] [Accepted: 03/10/2023] [Indexed: 03/18/2023] Open
Abstract
Inbreeding is the crossing of closely related individuals in nature or a plantation or self-pollinating plants, which produces plants with high homozygosity. This process can reduce genetic diversity in the offspring and decrease heterozygosity, whereas inbred depression (ID) can often reduce viability. Inbred depression is common in plants and animals and has played a significant role in evolution. In the review, we aim to show that inbreeding can, through the action of epigenetic mechanisms, affect gene expression, resulting in changes in the metabolism and phenotype of organisms. This is particularly important in plant breeding because epigenetic profiles can be linked to the deterioration or improvement of agriculturally important characteristics.
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9
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Fukagawa T, Kakutani T. Transgenerational epigenetic control of constitutive heterochromatin, transposons, and centromeres. Curr Opin Genet Dev 2023; 78:102021. [PMID: 36716679 DOI: 10.1016/j.gde.2023.102021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 12/20/2022] [Accepted: 01/04/2023] [Indexed: 01/30/2023]
Abstract
Epigenetic mechanisms are important not only for development but also for genome stability and chromosome dynamics. The latter types of epigenetic controls can often be transgenerational. Here, we review recent progress in two examples of transgenerational epigenetic control: i) the control of constitutive heterochromatin and transposable elements and ii) epigenetic mechanisms that regulate centromere specification and functions. We also discuss the biological significance of enigmatic associations among centromeres, transposons, and constitutive heterochromatin.
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Affiliation(s)
- Tatsuo Fukagawa
- Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka 565-0871, Japan. https://twitter.com/tatsuofukagawa1
| | - Tetsuji Kakutani
- Department of Biological Sciences, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan.
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10
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Chen B, Guo Y, Zhang X, Wang L, Cao L, Zhang T, Zhang Z, Zhou W, Xie L, Wang J, Sun S, Yang C, Zhang Q. Climate-responsive DNA methylation is involved in the biosynthesis of lignin in birch. FRONTIERS IN PLANT SCIENCE 2022; 13:1090967. [PMID: 36531363 PMCID: PMC9757698 DOI: 10.3389/fpls.2022.1090967] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Accepted: 11/22/2022] [Indexed: 06/17/2023]
Abstract
Lignin is one of the most important secondary metabolites and essential to the formation of cell walls. Changes in lignin biosynthesis have been reported to be associated with environmental variations and can influence plant fitness and their adaptation to abiotic stresses. However, the molecular mechanisms underlying this association remain unclear. In this study, we evaluated the relations between the lignin biosynthesis and environmental factors and explored the role of epigenetic modification (DNA methylation) in contributing to these relations if any in natural birch. Significantly negative correlations were observed between the lignin content and temperature ranges. Analyzing the transcriptomes of birches in two habitats with different temperature ranges showed that the expressions of genes and transcription factors (TFs) involving lignin biosynthesis were significantly reduced at higher temperature ranges. Whole-genome bisulfite sequencing revealed that promoter DNA methylation of two NAC-domain TFs, BpNST1/2 and BpSND1, may be involved in the inhibition of these gene expressions, and thereby reduced the content of lignin. Based on these results we proposed a DNA methylation-mediated lignin biosynthesis model which responds to environmental factors. Overall, this study suggests the possibility of environmental signals to induce epigenetic variations that result in changes in lignin content, which can aid to develop resilient plants to combat ongoing climate changes or to manipulate secondary metabolite biosynthesis for agricultural, medicinal, or industrial values.
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Affiliation(s)
- Bowei Chen
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin, China
- College of Life Science, Northeast Forestry University, Harbin, China
| | - Yile Guo
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin, China
- College of Life Science, Northeast Forestry University, Harbin, China
| | - Xu Zhang
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin, China
- College of Life Science, Northeast Forestry University, Harbin, China
| | - Lishan Wang
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin, China
- College of Life Science, Northeast Forestry University, Harbin, China
| | - Lesheng Cao
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin, China
- College of Life Science, Northeast Forestry University, Harbin, China
| | - Tianxu Zhang
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin, China
- College of Life Science, Northeast Forestry University, Harbin, China
| | - Zihui Zhang
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin, China
- College of Life Science, Northeast Forestry University, Harbin, China
| | - Wei Zhou
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin, China
- College of Life Science, Northeast Forestry University, Harbin, China
| | - Linan Xie
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin, China
- College of Life Science, Northeast Forestry University, Harbin, China
| | - Jiang Wang
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin, China
- College of Life Science, Northeast Forestry University, Harbin, China
| | - Shanwen Sun
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin, China
- College of Life Science, Northeast Forestry University, Harbin, China
| | - Chuanping Yang
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin, China
| | - Qingzhu Zhang
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin, China
- College of Life Science, Northeast Forestry University, Harbin, China
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11
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Conditional GWAS of non-CG transposon methylation in Arabidopsis thaliana reveals major polymorphisms in five genes. PLoS Genet 2022; 18:e1010345. [PMID: 36084135 PMCID: PMC9491579 DOI: 10.1371/journal.pgen.1010345] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 09/21/2022] [Accepted: 07/16/2022] [Indexed: 11/19/2022] Open
Abstract
Genome-wide association studies (GWAS) have revealed that the striking natural variation for DNA CHH-methylation (mCHH; H is A, T, or C) of transposons has oligogenic architecture involving major alleles at a handful of known methylation regulators. Here we use a conditional GWAS approach to show that CHG-methylation (mCHG) has a similar genetic architecture—once mCHH is statistically controlled for. We identify five key trans-regulators that appear to modulate mCHG levels, and show that they interact with a previously identified modifier of mCHH in regulating natural transposon mobilization. DNA methylation is an epigenetic mark common across eukaryotes. It is associated with transcriptional silencing, in particular of transposable elements. Multiple elements, including epigenetic inheritance, shape DNA methylation patterns, and the complexity makes it challenging to dissect the regulation. Our work on the 1001 Arabidopsis Epigenomes project led to the unexpected discovery that much of the natural variation for CHH methylation (mCHH; H is A, T, or C) on transposable elements could be attributed to allelic variation in three genes known to be involved in epigenetic regulation. However, our analysis of methylation in other sequence contexts (mCHG and mCG) revealed no genetic regulator. Here we show that if mCHG variation is analyzed while taking mCHH into account, mCHG is also strongly influenced by allelic variation in a small number of genes with known or highly plausible direct roles in epigenetic regulation. The presence of common allelic variation of large effect is suggestive of some form of local adaptation. The nature of this adaptation remains obscure, but we present further evidence that allelic variation regulating DNA methylation influences transposon mobilization.
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12
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Cheng J, Xu L, Bergér V, Bruckmann A, Yang C, Schubert V, Grasser KD, Schnittger A, Zheng B, Jiang H. H3K9 demethylases IBM1 and JMJ27 are required for male meiosis in Arabidopsis thaliana. THE NEW PHYTOLOGIST 2022; 235:2252-2269. [PMID: 35638341 DOI: 10.1111/nph.18286] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Accepted: 05/25/2022] [Indexed: 06/15/2023]
Abstract
Dimethylation of histone H3 lysine 9 (H3K9me2), a crucial modification for heterochromatin formation and transcriptional silencing, is essential for proper meiotic prophase progression in mammals. We analyzed meiotic defects and generated genome-wide profiles of H3K9me2 and transcriptomes for the mutants of H3K9 demethylases. Moreover, we also identified proteins interacting with H3K9 demethylases. H3K9me2 is usually found at transposable elements and repetitive sequences but is absent from the bodies of protein-coding genes. In this study, we show that the Arabidopsis thaliana H3K9 demethylases IBM1 and JMJ27 cooperatively regulate crossover formation and chromosome segregation. They protect thousands of protein-coding genes from ectopic H3K9me2, including genes essential for meiotic prophase progression. In addition to removing H3K9me2, IBM1 and JMJ27 interact with the Precocious Dissociation of Sisters 5 (PDS5) cohesin complex cofactors. The pds5 mutant shared similar transcriptional alterations with ibm1 jmj27, including meiosis-essential genes, yet without affecting H3K9me2 levels. Hence, PDS5s, together with IBM1 and JMJ27, regulate male meiosis and gene expression independently of H3K9 demethylation. These findings uncover a novel role of H3K9me2 removal in meiosis and a new function of H3K9 demethylases and cohesin cofactors in meiotic transcriptional regulation.
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Affiliation(s)
- Jinping Cheng
- Leibniz Institute of Plant Genetics and Crop Plant Research, Gatersleben, 06466, Germany
| | - Linhao Xu
- Leibniz Institute of Plant Genetics and Crop Plant Research, Gatersleben, 06466, Germany
| | - Valentin Bergér
- Cell Biology & Plant Biochemistry, Biochemistry Center, University of Regensburg, Regensburg, 93053, Germany
| | - Astrid Bruckmann
- Department of Biochemistry, Regensburg Center for Biochemistry, University of Regensburg, Regensburg, 93053, Germany
| | - Chao Yang
- Department of Developmental Biology, University of Hamburg, Hamburg, 20146, Germany
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China
| | - Veit Schubert
- Leibniz Institute of Plant Genetics and Crop Plant Research, Gatersleben, 06466, Germany
| | - Klaus D Grasser
- Cell Biology & Plant Biochemistry, Biochemistry Center, University of Regensburg, Regensburg, 93053, Germany
| | - Arp Schnittger
- Department of Developmental Biology, University of Hamburg, Hamburg, 20146, Germany
| | - Binglian Zheng
- State Key Laboratory of Genetic Engineering, Ministry of Education Key Laboratory of Biodiversity Sciences and Ecological Engineering, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Hua Jiang
- Leibniz Institute of Plant Genetics and Crop Plant Research, Gatersleben, 06466, Germany
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13
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To TK, Kakutani T. Crosstalk among pathways to generate DNA methylome. CURRENT OPINION IN PLANT BIOLOGY 2022; 68:102248. [PMID: 35724481 DOI: 10.1016/j.pbi.2022.102248] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Revised: 05/19/2022] [Accepted: 05/19/2022] [Indexed: 06/15/2023]
Abstract
Cytosine is methylated in both CpG and non-CpG contexts (mCG and mCH, respectively) in plant genomes. Although mCG and mCH are almost independent in regard to their "maintenance," recent studies uncovered crosstalk between them during their "establishment," which unexpectedly functions in both RNAi-dependent and -independent pathways. In addition, the importance of linker histone H1 and variants of histone H2A to DNA methylation dynamics is starting to be understood. We summarize these new aspects of mechanisms to generate DNA methylomes and discuss future prospects.
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Affiliation(s)
- Taiko Kim To
- Department of Biological Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Tetsuji Kakutani
- Department of Biological Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
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14
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Hazarika RR, Serra M, Zhang Z, Zhang Y, Schmitz RJ, Johannes F. Molecular properties of epimutation hotspots. NATURE PLANTS 2022; 8:146-156. [PMID: 35087209 PMCID: PMC8866225 DOI: 10.1038/s41477-021-01086-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 12/08/2021] [Indexed: 06/14/2023]
Abstract
Mistakes in the maintenance of CG methylation are a source of heritable epimutations in plants. Multigenerational surveys indicate that the rate of these stochastic events varies substantially across the genome, with some regions harbouring localized 'epimutation hotspots'. Using Arabidopsis as a model, we show that epimutation hotspots are indexed by a specific set of chromatin states that map to subregions of gene body methylation genes. Although these regions comprise only ~12% of all CGs in the genome, they account for ~63% of all epimutation events per unit time. Molecular profiling revealed that these regions contain unique sequence features, harbour steady-state intermediate methylation levels and act as putative targets of antagonistic DNA methylation pathways. We further demonstrate that experimentally induced shifts in steady-state methylation in these hotspot regions are sufficient to significantly alter local epimutation intensities. Our work lays the foundation for dissecting the molecular mechanisms and evolutionary consequences of epimutation hotspots in plants.
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Affiliation(s)
- Rashmi R Hazarika
- Department of Molecular Life Sciences, Technical University of Munich, Freising, Germany
- TUM Institute for Advanced Study, Garching, Germany
| | - Michele Serra
- Department of Molecular Life Sciences, Technical University of Munich, Freising, Germany
| | - Zhilin Zhang
- Department of Molecular Life Sciences, Technical University of Munich, Freising, Germany
| | - Yinwen Zhang
- Department of Genetics, The University of Georgia, Athens, GA, USA
| | - Robert J Schmitz
- TUM Institute for Advanced Study, Garching, Germany.
- Department of Genetics, The University of Georgia, Athens, GA, USA.
| | - Frank Johannes
- Department of Molecular Life Sciences, Technical University of Munich, Freising, Germany.
- TUM Institute for Advanced Study, Garching, Germany.
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15
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Hüther P, Hagmann J, Nunn A, Kakoulidou I, Pisupati R, Langenberger D, Weigel D, Johannes F, Schultheiss SJ, Becker C. MethylScore, a pipeline for accurate and context-aware identification of differentially methylated regions from population-scale plant whole-genome bisulfite sequencing data. QUANTITATIVE PLANT BIOLOGY 2022; 3:e19. [PMID: 37077980 PMCID: PMC10095865 DOI: 10.1017/qpb.2022.14] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 07/14/2022] [Accepted: 07/15/2022] [Indexed: 05/03/2023]
Abstract
Whole-genome bisulfite sequencing (WGBS) is the standard method for profiling DNA methylation at single-nucleotide resolution. Different tools have been developed to extract differentially methylated regions (DMRs), often built upon assumptions from mammalian data. Here, we present MethylScore, a pipeline to analyse WGBS data and to account for the substantially more complex and variable nature of plant DNA methylation. MethylScore uses an unsupervised machine learning approach to segment the genome by classification into states of high and low methylation. It processes data from genomic alignments to DMR output and is designed to be usable by novice and expert users alike. We show how MethylScore can identify DMRs from hundreds of samples and how its data-driven approach can stratify associated samples without prior information. We identify DMRs in the A. thaliana 1,001 Genomes dataset to unveil known and unknown genotype-epigenotype associations .
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Affiliation(s)
- Patrick Hüther
- Gregor Mendel Institute of Molecular Plant Biology GmbH, Austrian Academy of Sciences, Vienna BioCenter (VBC), 1030 Vienna, Austria
- LMU Biocenter, Faculty of Biology, Ludwig-Maximilians-University Munich, 82152 Martinsried, Germany
| | | | - Adam Nunn
- ecSeq Bioinformatics GmbH, 04103 Leipzig, Germany
- Department of Computer Science, Leipzig University, 04107 Leipzig, Germany
| | - Ioanna Kakoulidou
- Department of Plant Sciences, Technical University of Munich, 85354 Freising, Germany
| | - Rahul Pisupati
- Gregor Mendel Institute of Molecular Plant Biology GmbH, Austrian Academy of Sciences, Vienna BioCenter (VBC), 1030 Vienna, Austria
| | | | - Detlef Weigel
- Department of Molecular Biology, Max Planck Institute for Biology, 72076 Tübingen, Germany
| | - Frank Johannes
- Department of Plant Sciences, Technical University of Munich, 85354 Freising, Germany
- Institute for Advanced Study, Technical University of Munich, 85748 Garching, Germany
| | | | - Claude Becker
- Gregor Mendel Institute of Molecular Plant Biology GmbH, Austrian Academy of Sciences, Vienna BioCenter (VBC), 1030 Vienna, Austria
- LMU Biocenter, Faculty of Biology, Ludwig-Maximilians-University Munich, 82152 Martinsried, Germany
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