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Nkongolo K, Michael P. Reduced representation bisulfite sequencing (RRBS) analysis reveals variation in distribution and levels of DNA methylation in white birch ( Betula papyrifera) exposed to nickel. Genome 2024. [PMID: 39226484 DOI: 10.1139/gen-2024-0019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/05/2024]
Abstract
Research in understanding the role of genetics and epigenetics in plant adaptations to environmental stressors such as metals is still in its infancy. The objective of the present study is to assess the effect of nickel on DNA methylation level and distribution in white birch (Betula papyrifera Marshall) using reduced representation bisulfite sequencing (RRBS). The distribution of methylated C sites of each sample revealed that the level of methylation was much higher in CG context varying between 54% and 65%, followed by CHG (24%-31.5%), and then CHH with the methylation rate between 3.3% and 5.2%. The analysis of differentially methylated regions (DMR) revealed that nickel induced both hypermethylation and hypomethylation when compared to water. Detailed analysis showed for the first time that nickel induced a higher level of hypermethylation compared to controls, while potassium triggers a higher level of hypomethylation compared to nickel. Surprisingly, the analysis of the distribution of DMRs revealed that 38%-42% were located in gene bodies, 20%-24% in exon, 19%-20% in intron, 16%-17% in promoters, and 0.03%-0.04% in transcription start site. RRBS was successful in detecting and mapping DMR in plants exposed to nickel.
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Affiliation(s)
- Kabwe Nkongolo
- Biomolecular Sciences Program and School of Natural Sciences, Laurentian University, Sudbury, ON P3E 2C6, Canada
| | - Paul Michael
- Biomolecular Sciences Program and School of Natural Sciences, Laurentian University, Sudbury, ON P3E 2C6, Canada
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2
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Alakärppä E, Salo HM, Suokas M, Jokipii-Lukkari S, Vuosku J, Häggman H. Targeted bisulfite sequencing of Scots pine adaptation-related genes. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2024; 346:112173. [PMID: 38944158 DOI: 10.1016/j.plantsci.2024.112173] [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: 05/13/2024] [Revised: 06/24/2024] [Accepted: 06/27/2024] [Indexed: 07/01/2024]
Abstract
During environmental changes, epigenetic processes can enable adaptive responses faster than natural selection. In plants, very little is known about the role of DNA methylation during long-term adaptation. Scots pine is a widely distributed coniferous species which must adapt to different environmental conditions throughout its long lifespan. Thus, epigenetic modifications may contribute towards this direction. We provide bisulfite next-generation sequencing data from the putative promoters and exons of eight adaptation-related genes (A3IP2, CCA1, COL1, COL2, FTL2, MFT1, PHYO, and ZTL) in three Scots pine populations located in northern and southern parts of Finland. DNA methylation levels were studied in the two seed tissues: the maternal megagametophyte which contributes to embryo viability, and the biparental embryo which represents the next generation. In most genes, differentially methylated cytosines (DMCs) were in line with our previously demonstrated gene expression differences found in the same Scots pine populations. In addition, we found a strong correlation of total methylation levels between the embryo and megagametophyte tissues of a given individual tree, which indicates that DNA methylation can be inherited from the maternal parent. In conclusion, our results imply that DNA methylation differences may contribute to the adaptation of Scots pine populations in different climatic conditions.
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Affiliation(s)
- Emmi Alakärppä
- Ecology and Genetics Research Unit, University of Oulu, PO Box 3000, Oulu FI-90014, Finland.
| | - Heikki M Salo
- Ecology and Genetics Research Unit, University of Oulu, PO Box 3000, Oulu FI-90014, Finland
| | - Marko Suokas
- Ecology and Genetics Research Unit, University of Oulu, PO Box 3000, Oulu FI-90014, Finland
| | - Soile Jokipii-Lukkari
- Ecology and Genetics Research Unit, University of Oulu, PO Box 3000, Oulu FI-90014, Finland
| | - Jaana Vuosku
- Ecology and Genetics Research Unit, University of Oulu, PO Box 3000, Oulu FI-90014, Finland
| | - Hely Häggman
- Ecology and Genetics Research Unit, University of Oulu, PO Box 3000, Oulu FI-90014, Finland
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3
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Hamann E, Groen SC, Dunivant TS, Ćalić I, Cochran C, Konshok R, Purugganan MD, Franks SJ. Selection on genome-wide gene expression plasticity of rice in wet and dry field environments. Mol Ecol 2024:e17522. [PMID: 39215462 DOI: 10.1111/mec.17522] [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: 01/30/2024] [Revised: 07/29/2024] [Accepted: 08/16/2024] [Indexed: 09/04/2024]
Abstract
Gene expression can be highly plastic in response to environmental variation. However, we know little about how expression plasticity is shaped by natural selection and evolves in wild and domesticated species. We used genotypic selection analysis to characterize selection on drought-induced plasticity of over 7,500 leaf transcripts of 118 rice accessions (genotypes) from different environmental conditions grown in a field experiment. Gene expression plasticity was neutral for most gradually plastic transcripts, but transcripts with discrete patterns of expression showed stronger selection on expression plasticity. Whether plasticity was adaptive and co-gradient or maladaptive and counter-gradient varied among varietal groups. No transcripts that experienced selection for plasticity across environments showed selection against plasticity within environments, indicating a lack of evidence for costs of adaptive plasticity that may constrain its evolution. Selection on expression plasticity was influenced by degree of plasticity, transcript length and gene body methylation. We observed positive selection on plasticity of co-expression modules containing transcripts involved in photosynthesis, translation and responsiveness to abiotic stress. Taken together, these results indicate that patterns of selection on expression plasticity were context-dependent and likely associated with environmental conditions of varietal groups, but that the evolution of adaptive plasticity would likely not be constrained by opposing patterns of selection on plasticity within compared to across environments. These results offer a genome-wide view of patterns of selection and ecological constraints on gene expression plasticity and provide insights into the interplay between plastic and evolutionary responses to drought at the molecular level.
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Affiliation(s)
- Elena Hamann
- Department of Biological Sciences, Fordham University, Bronx, New York, USA
- Department of Biology, Institute of Plant Ecology and Evolution, Heinrich-Heine University Düsseldorf, Düsseldorf, Germany
| | - Simon C Groen
- Department of Nematology, University of California Riverside, Riverside, California, USA
- Center for Plant Cell Biology, Institute for Integrative Genome Biology, University of California Riverside, Riverside, California, USA
- Department of Botany and Plant Sciences, University of California Riverside, Riverside, California, USA
- Department of Biology, Center for Genomics and Systems Biology, New York University, New York, New York, USA
| | - Taryn S Dunivant
- Department of Nematology, University of California Riverside, Riverside, California, USA
- Center for Plant Cell Biology, Institute for Integrative Genome Biology, University of California Riverside, Riverside, California, USA
- Department of Botany and Plant Sciences, University of California Riverside, Riverside, California, USA
| | - Irina Ćalić
- Department of Biological Sciences, Fordham University, Bronx, New York, USA
| | - Colleen Cochran
- Department of Biological Sciences, Fordham University, Bronx, New York, USA
| | - Rachel Konshok
- Department of Biological Sciences, Fordham University, Bronx, New York, USA
| | - Michael D Purugganan
- Department of Biology, Center for Genomics and Systems Biology, New York University, New York, New York, USA
- Center for Genomics and Systems Biology, NYU Abu Dhabi Research Institute, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates
| | - Steven J Franks
- Department of Biological Sciences, Fordham University, Bronx, New York, USA
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4
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Pal S, Dhar R. Living in a noisy world-origins of gene expression noise and its impact on cellular decision-making. FEBS Lett 2024; 598:1673-1691. [PMID: 38724715 DOI: 10.1002/1873-3468.14898] [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: 12/21/2023] [Revised: 03/23/2024] [Accepted: 03/27/2024] [Indexed: 07/23/2024]
Abstract
The expression level of a gene can vary between genetically identical cells under the same environmental condition-a phenomenon referred to as gene expression noise. Several studies have now elucidated a central role of transcription factors in the generation of expression noise. Transcription factors, as the key components of gene regulatory networks, drive many important cellular decisions in response to cellular and environmental signals. Therefore, a very relevant question is how expression noise impacts gene regulation and influences cellular decision-making. In this Review, we summarize the current understanding of the molecular origins of expression noise, highlighting the role of transcription factors in this process, and discuss the ways in which noise can influence cellular decision-making. As advances in single-cell technologies open new avenues for studying expression noise as well as gene regulatory circuits, a better understanding of the influence of noise on cellular decisions will have important implications for many biological processes.
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Affiliation(s)
- Sampriti Pal
- Department of Bioscience and Biotechnology, IIT Kharagpur, India
| | - Riddhiman Dhar
- Department of Bioscience and Biotechnology, IIT Kharagpur, India
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5
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Baduel P, Sammarco I, Barrett R, Coronado‐Zamora M, Crespel A, Díez‐Rodríguez B, Fox J, Galanti D, González J, Jueterbock A, Wootton E, Harney E. The evolutionary consequences of interactions between the epigenome, the genome and the environment. Evol Appl 2024; 17:e13730. [PMID: 39050763 PMCID: PMC11266121 DOI: 10.1111/eva.13730] [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: 11/01/2023] [Revised: 03/30/2024] [Accepted: 05/22/2024] [Indexed: 07/27/2024] Open
Abstract
The epigenome is the suite of interacting chemical marks and molecules that helps to shape patterns of development, phenotypic plasticity and gene regulation, in part due to its responsiveness to environmental stimuli. There is increasing interest in understanding the functional and evolutionary importance of this sensitivity under ecologically realistic conditions. Observations that epigenetic variation abounds in natural populations have prompted speculation that it may facilitate evolutionary responses to rapid environmental perturbations, such as those occurring under climate change. A frequent point of contention is whether epigenetic variants reflect genetic variation or are independent of it. The genome and epigenome often appear tightly linked and interdependent. While many epigenetic changes are genetically determined, the converse is also true, with DNA sequence changes influenced by the presence of epigenetic marks. Understanding how the epigenome, genome and environment interact with one another is therefore an essential step in explaining the broader evolutionary consequences of epigenomic variation. Drawing on results from experimental and comparative studies carried out in diverse plant and animal species, we synthesize our current understanding of how these factors interact to shape phenotypic variation in natural populations, with a focus on identifying similarities and differences between taxonomic groups. We describe the main components of the epigenome and how they vary within and between taxa. We review how variation in the epigenome interacts with genetic features and environmental determinants, with a focus on the role of transposable elements (TEs) in integrating the epigenome, genome and environment. And we look at recent studies investigating the functional and evolutionary consequences of these interactions. Although epigenetic differentiation in nature is likely often a result of drift or selection on stochastic epimutations, there is growing evidence that a significant fraction of it can be stably inherited and could therefore contribute to evolution independently of genetic change.
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Affiliation(s)
- Pierre Baduel
- Institut de Biologie de l'Ecole Normale SupérieurePSL University, CNRSParisFrance
| | - Iris Sammarco
- Institute of Botany of the Czech Academy of SciencesPrůhoniceCzechia
| | - Rowan Barrett
- Redpath Museum and Department of BiologyMcGill UniversityMontrealCanada
| | | | | | | | - Janay Fox
- Redpath Museum and Department of BiologyMcGill UniversityMontrealCanada
| | - Dario Galanti
- Institute of Evolution and Ecology (EvE)University of TuebingenTübingenGermany
| | | | - Alexander Jueterbock
- Algal and Microbial Biotechnology Division, Faculty of Biosciences and AquacultureNord UniversityBodøNorway
| | - Eric Wootton
- Redpath Museum and Department of BiologyMcGill UniversityMontrealCanada
| | - Ewan Harney
- Institute of Evolutionary BiologyCSIC, UPFBarcelonaSpain
- School of BiosciencesUniversity of SheffieldSheffieldUK
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6
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Yadav S, Meena S, Kalwan G, Jain PK. DNA methylation: an emerging paradigm of gene regulation under drought stress in plants. Mol Biol Rep 2024; 51:311. [PMID: 38372841 DOI: 10.1007/s11033-024-09243-9] [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: 09/27/2023] [Accepted: 01/11/2024] [Indexed: 02/20/2024]
Abstract
Drought is an enormous threat to global crop production. In order to ensure food security for the burgeoning population, we must develop drought tolerant crop varieties. This necessitates the identification of drought-responsive genes and understanding the mechanisms involved in their regulation. DNA methylation is a widely studied mechanism of epigenetic regulation of gene expression, which is known to play vital role in conferring tolerance to various biotic and abiotic stress factors. The recent advances in next-generation sequencing (NGS) technologies, has allowed unprecedented access to genome-wide methylation marks, with single base resolution. The most important roles of DNA methylation have been studied in terms of gene body methylation (gbM), which is associated with regulation of both transcript abundance and its stability. The availability of mutants for the various genes encoding enzymes involved in methylation of DNA has allowed ascertainment of the biological significance of methylation. Even though a vast number of reports have emerged in the recent past, where both genome-wide methylation landscape and locus specific changes in DNA methylation have been studied, a conclusive picture with regards to the biological role of DNA methylation is still lacking. Compounding this, is the lack of sufficient evidence supporting the heritability of these epigenetic changes. Amongst the various epigenetic variations, the DNA methylation changes are observed to be the most stable. This review describes the drought-induced changes in DNA methylation identified across different plant species. We also briefly describe the stress memory contributed by these changes. The identification of heritable, drought-induced methylation marks would broaden the scope of crop improvement in the future.
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Affiliation(s)
- Sheel Yadav
- ICAR-National Institute for Plant Biotechnology, New Delhi, 110012, India
- PG School, ICAR-Indian Agricultural Research Institute, New Delhi, 110012, India
- Division of Genomic Resources, ICAR-National Bureau of Plant Genetic Resources, New Delhi, 110012, India
| | - Shashi Meena
- PG School, ICAR-Indian Agricultural Research Institute, New Delhi, 110012, India
- Division of Plant Physiology, ICAR-Indian Agricultural Research Institute, New Delhi, 110012, India
| | - Gopal Kalwan
- ICAR-National Institute for Plant Biotechnology, New Delhi, 110012, India
- PG School, ICAR-Indian Agricultural Research Institute, New Delhi, 110012, India
| | - P K Jain
- ICAR-National Institute for Plant Biotechnology, New Delhi, 110012, India.
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7
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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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8
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Liao RY, Wang JW. Analysis of meristems and plant regeneration at single-cell resolution. CURRENT OPINION IN PLANT BIOLOGY 2023; 74:102378. [PMID: 37172363 DOI: 10.1016/j.pbi.2023.102378] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 03/23/2023] [Accepted: 04/12/2023] [Indexed: 05/14/2023]
Abstract
Rapid development of high-throughput single-cell RNA sequencing (scRNA-seq) technologies offers exciting opportunities to reveal new and rare cell types, previously hidden cell states, and continuous developmental trajectories. In this review, we first illustrate the ways in which scRNA-seq enables researchers to distinguish between distinct plant cell populations, delineate cell cycle continuums, and infer continuous differentiation trajectories of diverse cell types in shoots, roots, and floral and vascular meristems with unprecedented resolution. We then highlight the emerging power of scRNA-seq to dissect cell heterogeneity in regenerating tissues and uncover the cellular basis of cell reprogramming and stem cell commitment during plant regeneration. We conclude by discussing related outstanding questions in the field.
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Affiliation(s)
- Ren-Yu Liao
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences (CEMPS), Institute of Plant Physiology and Ecology (SIPPE), Chinese Academy of Sciences (CAS), Shanghai, 200032, China; University of Chinese Academy of Sciences, Shanghai, 200032, China
| | - Jia-Wei Wang
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences (CEMPS), Institute of Plant Physiology and Ecology (SIPPE), Chinese Academy of Sciences (CAS), Shanghai, 200032, China; School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China.
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9
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Wu X, Bhatia N, Grozinger CM, Yi SV. Comparative studies of genomic and epigenetic factors influencing transcriptional variation in two insect species. G3 GENES|GENOMES|GENETICS 2022; 12:6693626. [PMID: 36137211 PMCID: PMC9635643 DOI: 10.1093/g3journal/jkac230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 08/05/2022] [Indexed: 11/16/2022]
Abstract
Different genes show different levels of expression variability. For example, highly expressed genes tend to exhibit less expression variability. Genes whose promoters have TATA box and initiator motifs tend to have increased expression variability. On the other hand, DNA methylation of transcriptional units, or gene body DNA methylation, is associated with reduced gene expression variability in many species. Interestingly, some insect lineages, most notably Diptera including the canonical model insect Drosophila melanogaster, have lost DNA methylation. Therefore, it is of interest to determine whether genomic features similarly influence gene expression variability in lineages with and without DNA methylation. We analyzed recently generated large-scale data sets in D. melanogaster and honey bee (Apis mellifera) to investigate these questions. Our analysis shows that increased gene expression levels are consistently associated with reduced expression variability in both species, while the presence of TATA box is consistently associated with increased gene expression variability. In contrast, initiator motifs and gene lengths have weak effects limited to some data sets. Importantly, we show that a sequence characteristics indicative of gene body DNA methylation is strongly and negatively associate with gene expression variability in honey bees, while it shows no such association in D. melanogaster. These results suggest the evolutionary loss of DNA methylation in some insect lineages has reshaped the molecular mechanisms concerning the regulation of gene expression variability.
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Affiliation(s)
| | - Neharika Bhatia
- School of Biological Sciences, Institute for Bioengineering and Bioscience, Georgia Institute of Technology , Atlanta, GA 30332, USA
| | - Christina M Grozinger
- Department of Entomology, Center for Pollinator Research, Huck Institutes of the Life Sciences, Pennsylvania State University , University Park, PA 16801, USA
| | - Soojin V Yi
- School of Biological Sciences, Institute for Bioengineering and Bioscience, Georgia Institute of Technology , Atlanta, GA 30332, USA
- Department of Ecology, Evolution and Marine Biology, University of California Santa Barbara , Santa Barbara, CA 93106, USA
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10
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Muyle AM, Seymour DK, Lv Y, Huettel B, Gaut BS. Gene-body methylation in plants: mechanisms, functions and important implications for understanding evolutionary processes. Genome Biol Evol 2022; 14:6550137. [PMID: 35298639 PMCID: PMC8995044 DOI: 10.1093/gbe/evac038] [Citation(s) in RCA: 38] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/11/2022] [Indexed: 11/13/2022] Open
Abstract
Gene body methylation (gbM) is an epigenetic mark where gene exons are methylated in the CG context only, as opposed to CHG and CHH contexts (where H stands for A, C, or T). CG methylation is transmitted transgenerationally in plants, opening the possibility that gbM may be shaped by adaptation. This presupposes, however, that gbM has a function that affects phenotype, which has been a topic of debate in the literature. Here, we review our current knowledge of gbM in plants. We start by presenting the well-elucidated mechanisms of plant gbM establishment and maintenance. We then review more controversial topics: the evolution of gbM and the potential selective pressures that act on it. Finally, we discuss the potential functions of gbM that may affect organismal phenotypes: gene expression stabilization and upregulation, inhibition of aberrant transcription (reverse and internal), prevention of aberrant intron retention, and protection against TE insertions. To bolster the review of these topics, we include novel analyses to assess the effect of gbM on transcripts. Overall, a growing body of literature finds that gbM correlates with levels and patterns of gene expression. It is not clear, however, if this is a causal relationship. Altogether, functional work suggests that the effects of gbM, if any, must be relatively small, but there is nonetheless evidence that it is shaped by natural selection. We conclude by discussing the potential adaptive character of gbM and its implications for an updated view of the mechanisms of adaptation in plants.
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Affiliation(s)
| | | | - Yuanda Lv
- Provincial Key Laboratory of Agrobiology, Institute of Crop Germplasm and Biotechnology, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Bruno Huettel
- Max Planck Genome Centre Cologne, Max Planck Institute for Plant Breeding, Cologne, Germany
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11
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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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12
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Wang Y, Dai A, Chen Y, Tang T. Gene Body Methylation Confers Transcription Robustness in Mangroves During Long-Term Stress Adaptation. FRONTIERS IN PLANT SCIENCE 2021; 12:733846. [PMID: 34630483 PMCID: PMC8493031 DOI: 10.3389/fpls.2021.733846] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 09/02/2021] [Indexed: 05/23/2023]
Abstract
Whether induced epigenetic changes contribute to long-term adaptation remains controversial. Recent studies indicate that environmentally cued changes in gene body methylation (gbM) can facilitate acclimatization. However, such changes are often associated with genetic variation and their contribution to long-term stress adaptation remains unclear. Using whole-genome bisulfite sequencing, we examined evolutionary gains and losses of gbM in mangroves that adapted to extreme intertidal environments. We treated mangrove seedlings with salt stress, and investigated expression changes in relation with stress-induced or evolutionarily-acquired gbM changes. Evolution and function of gbM was compared with that of genetic variation. Mangroves gained much more gbM than their terrestrial relatives, mainly through convergent evolution. Genes that convergently gained gbM during evolution are more likely to become methylated in response to salt stress in species where they are normally not marked. Stress-induced and evolutionarily convergent gains of gbM both correlate with reduction in expression variation, conferring genome-wide expression robustness under salt stress. Moreover, convergent gbM evolution is uncoupled with convergent sequence evolution. Our findings suggest that transgenerational inheritance of acquired gbM helps environmental canalization of gene expression, facilitating long-term stress adaptation of mangroves in the face of a severe reduction in genetic diversity.
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Affiliation(s)
- Yushuai Wang
- State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Aimei Dai
- State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Yiping Chen
- State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Tian Tang
- State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
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13
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The Underlying Nature of Epigenetic Variation: Origin, Establishment, and Regulatory Function of Plant Epialleles. Int J Mol Sci 2021; 22:ijms22168618. [PMID: 34445323 PMCID: PMC8395315 DOI: 10.3390/ijms22168618] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 08/03/2021] [Accepted: 08/08/2021] [Indexed: 11/17/2022] Open
Abstract
In plants, the gene expression and associated phenotypes can be modulated by dynamic changes in DNA methylation, occasionally being fixed in certain genomic loci and inherited stably as epialleles. Epiallelic variations in a population can occur as methylation changes at an individual cytosine position, methylation changes within a stretch of genomic regions, and chromatin changes in certain loci. Here, we focus on methylated regions, since it is unclear whether variations at individual methylated cytosines can serve any regulatory function, and the evidence for heritable chromatin changes independent of genetic changes is limited. While DNA methylation is known to affect and regulate wide arrays of plant phenotypes, most epialleles in the form of methylated regions have not been assigned any biological function. Here, we review how epialleles can be established in plants, serve a regulatory function, and are involved in adaptive processes. Recent studies suggest that most epialleles occur as byproducts of genetic variations, mainly from structural variants and Transposable Element (TE) activation. Nevertheless, epialleles that occur spontaneously independent of any genetic variations have also been described across different plant species. Here, we discuss how epialleles that are dependent and independent of genetic architecture are stabilized in the plant genome and how methylation can regulate a transcription relative to its genomic location.
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14
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Thibivilliers S, Libault M. Enhancing Our Understanding of Plant Cell-to-Cell Interactions Using Single-Cell Omics. FRONTIERS IN PLANT SCIENCE 2021; 12:696811. [PMID: 34421948 PMCID: PMC8375048 DOI: 10.3389/fpls.2021.696811] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 07/07/2021] [Indexed: 05/05/2023]
Abstract
Plants are composed of cells that physically interact and constantly adapt to their environment. To reveal the contribution of each plant cells to the biology of the entire organism, their molecular, morphological, and physiological attributes must be quantified and analyzed in the context of the morphology of the plant organs. The emergence of single-cell/nucleus omics technologies now allows plant biologists to access different modalities of individual cells including their epigenome and transcriptome to reveal the unique molecular properties of each cell composing the plant and their dynamic regulation during cell differentiation and in response to their environment. In this manuscript, we provide a perspective regarding the challenges and strategies to collect plant single-cell biological datasets and their analysis in the context of cellular interactions. As an example, we provide an analysis of the transcriptional regulation of the Arabidopsis genes controlling the differentiation of the root hair cells at the single-cell level. We also discuss the perspective of the use of spatial profiling to complement existing plant single-cell omics.
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Affiliation(s)
| | - Marc Libault
- Department of Agronomy and Horticulture, Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, NE, United States
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15
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DNA Methylation-An Epigenetic Mark in Mutagen-Treated Brachypodium distachyon Cells. PLANTS 2021; 10:plants10071408. [PMID: 34371611 PMCID: PMC8309452 DOI: 10.3390/plants10071408] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 07/07/2021] [Indexed: 12/15/2022]
Abstract
The chromatin structure is significantly influenced by some epigenetic modifications including DNA methylation. The nuclear organization plays an essential role in the cell response to external stresses including mutagens. We present an analysis of the correlation between epigenetic modifications and the instability of the Brachypodium distachyon genome, which are observed as micronuclei, following maleic hydrazide (MH) and nitroso-N-methylurea (MNU) treatments. We compared the level of DNA methylation in the control (untreated) and mutagen-treated B. distachyon nuclei. An immunostaining method using specific antibodies against modified DNA anti-5-methylcytosine was used for the evaluation of DNA methylation in a single nucleus and micronucleus. Interestingly, we showed an alteration of DNA methylation in cells after mutagenic treatments. The results indicate that DNA methylation might be involved in the response of the B. distachyon genome to mutagenic treatments. This demonstrates that analyses of the epigenetic modifications should be integrated into current plant genetic toxicology in order to explain the mechanisms of DNA damage and repair in plants.
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16
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Wang L, Liu F, Du L, Qin G. Single-Cell Transcriptome Analysis in Melanoma Using Network Embedding. Front Genet 2021; 12:700036. [PMID: 34290746 PMCID: PMC8287331 DOI: 10.3389/fgene.2021.700036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Accepted: 06/10/2021] [Indexed: 11/28/2022] Open
Abstract
Single-cell sequencing technology provides insights into the pathology of complex diseases like cancer. Here, we proposed a novel computational framework to explore the molecular mechanisms of cancer called melanoma. We first constructed a disease-specific cell–cell interaction network after data preprocessing and dimensionality reduction. Second, the features of cells in the cell–cell interaction network were learned by node2vec which is a graph embedding technology proposed previously. Then, consensus clusters were identified by considering different clustering algorithms. Finally, cell markers and cancer-related genes were further analyzed by integrating gene regulation pairs. We exploited our model on two independent datasets, which showed interesting results that the differences between clusters obtained by consensus clustering based on network embedding (CCNE) were observed obviously through visualization. For the KEGG pathway analysis of clusters, we found that all clusters are extremely related to MicroRNAs in cancer and HTLV-I infection, and the hub genes in cluster specific regulatory networks, i.e., ETS1, TP53, E2F1, and GATA3 are highly associated with melanoma. Furthermore, our method can also be extended to other scRNA-seq data.
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Affiliation(s)
- Liming Wang
- School of Computer Science and Technology, Xidian University, Xi'an, China
| | - Fangfang Liu
- School of Computer Science and Technology, Xidian University, Xi'an, China
| | - Longting Du
- School of Computer Science and Technology, Xidian University, Xi'an, China
| | - Guimin Qin
- School of Computer Science and Technology, Xidian University, Xi'an, China
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17
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Liu W, Gallego-Bartolomé J, Zhou Y, Zhong Z, Wang M, Wongpalee SP, Gardiner J, Feng S, Kuo PH, Jacobsen SE. Ectopic targeting of CG DNA methylation in Arabidopsis with the bacterial SssI methyltransferase. Nat Commun 2021; 12:3130. [PMID: 34035251 PMCID: PMC8149686 DOI: 10.1038/s41467-021-23346-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Accepted: 03/30/2021] [Indexed: 01/03/2023] Open
Abstract
The ability to target epigenetic marks like DNA methylation to specific loci is important in both basic research and in crop plant engineering. However, heritability of targeted DNA methylation, how it impacts gene expression, and which epigenetic features are required for proper establishment are mostly unknown. Here, we show that targeting the CG-specific methyltransferase M.SssI with an artificial zinc finger protein can establish heritable CG methylation and silencing of a targeted locus in Arabidopsis. In addition, we observe highly heritable widespread ectopic CG methylation mainly over euchromatic regions. This hypermethylation shows little effect on transcription while it triggers a mild but significant reduction in the accumulation of H2A.Z and H3K27me3. Moreover, ectopic methylation occurs preferentially at less open chromatin that lacks positive histone marks. These results outline general principles of the heritability and interaction of CG methylation with other epigenomic features that should help guide future efforts to engineer epigenomes. The ability to target DNA methylation to specific loci is important for both basic and applied research. Here, the authors fuse CG-specific methyltransferase SssI with an artificial zinc finger protein for DNA methylation targeting and show the chromatin features favorable for efficient gain of methylation.
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Affiliation(s)
- Wanlu Liu
- Department of Orthopedic of the Second Affiliated Hospital of Zhejiang University School of Medicine, Zhejiang University, Hangzhou, China. .,Zhejiang University-University of Edinburgh Institute (ZJU-UoE Institute), Zhejiang University School of Medicine, International Campus, Zhejiang University, Haining, China. .,Department of Molecular, Cell and Developmental Biology, University of California at Los Angeles, Los Angeles, CA, USA.
| | - Javier Gallego-Bartolomé
- Department of Molecular, Cell and Developmental Biology, University of California at Los Angeles, Los Angeles, CA, USA.,Instituto de Biología Molecular y Celular de Plantas (IBMCP), CSIC-Universidad Politécnica de Valencia, Valencia, Spain
| | - Yuxing Zhou
- Zhejiang University-University of Edinburgh Institute (ZJU-UoE Institute), Zhejiang University School of Medicine, International Campus, Zhejiang University, Haining, China
| | - Zhenhui Zhong
- Department of Molecular, Cell and Developmental Biology, University of California at Los Angeles, Los Angeles, CA, USA
| | - Ming Wang
- Department of Molecular, Cell and Developmental Biology, University of California at Los Angeles, Los Angeles, CA, USA
| | - Somsakul Pop Wongpalee
- Department of Molecular, Cell and Developmental Biology, University of California at Los Angeles, Los Angeles, CA, USA.,Department of Microbiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Jason Gardiner
- Department of Molecular, Cell and Developmental Biology, University of California at Los Angeles, Los Angeles, CA, USA
| | - Suhua Feng
- Department of Molecular, Cell and Developmental Biology, University of California at Los Angeles, Los Angeles, CA, USA.,Eli & Edythe Broad Center of Regenerative Medicine & Stem Cell Research, University of California at Los Angeles, Los Angeles, CA, USA
| | - Peggy Hsuanyu Kuo
- Department of Molecular, Cell and Developmental Biology, University of California at Los Angeles, Los Angeles, CA, USA
| | - Steven E Jacobsen
- Department of Molecular, Cell and Developmental Biology, University of California at Los Angeles, Los Angeles, CA, USA. .,Eli & Edythe Broad Center of Regenerative Medicine & Stem Cell Research, University of California at Los Angeles, Los Angeles, CA, USA. .,Howard Hughes Medical Institute, University of California at Los Angeles, Los Angeles, CA, USA.
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18
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Muyle A, Ross-Ibarra J, Seymour DK, Gaut BS. Gene body methylation is under selection in Arabidopsis thaliana. Genetics 2021; 218:6237897. [PMID: 33871638 PMCID: PMC8225343 DOI: 10.1093/genetics/iyab061] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 04/07/2021] [Indexed: 11/28/2022] Open
Abstract
In plants, mammals and insects, some genes are methylated in the CG dinucleotide context, a phenomenon called gene body methylation (gbM). It has been controversial whether this phenomenon has any functional role. Here, we took advantage of the availability of 876 leaf methylomes in Arabidopsis thaliana to characterize the population frequency of methylation at the gene level and to estimate the site-frequency spectrum of allelic states. Using a population genetics model specifically designed for epigenetic data, we found that genes with ancestral gbM are under significant selection to remain methylated. Conversely, ancestrally unmethylated genes were under selection to remain unmethylated. Repeating the analyses at the level of individual cytosines confirmed these results. Estimated selection coefficients were small, on the order of 4 Nes = 1.4, which is similar to the magnitude of selection acting on codon usage. We also estimated that A. thaliana is losing gbM threefold more rapidly than gaining it, which could be due to a recent reduction in the efficacy of selection after a switch to selfing. Finally, we investigated the potential function of gbM through its link with gene expression. Across genes with polymorphic methylation states, the expression of gene body methylated alleles was consistently and significantly higher than unmethylated alleles. Although it is difficult to disentangle genetic from epigenetic effects, our work suggests that gbM has a small but measurable effect on fitness, perhaps due to its association to a phenotype-like gene expression.
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Affiliation(s)
- Aline Muyle
- Ecology and Evolutionary Biology, University of California, Irvine, Irvine, CA 92697-2525, USA
| | - Jeffrey Ross-Ibarra
- Evolution and Ecology, Center for Population Biology and Genome Center, University of California, Davis, Davis, CA 95616, USA
| | - Danelle K Seymour
- Botany & Plant Sciences, University of California, Riverside, Riverside, CA 92521, USA
| | - Brandon S Gaut
- Ecology and Evolutionary Biology, University of California, Irvine, Irvine, CA 92697-2525, USA
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19
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Shahryary Y, Symeonidi A, Hazarika RR, Denkena J, Mubeen T, Hofmeister B, van Gurp T, Colomé-Tatché M, Verhoeven KJ, Tuskan G, Schmitz RJ, Johannes F. AlphaBeta: computational inference of epimutation rates and spectra from high-throughput DNA methylation data in plants. Genome Biol 2020; 21:260. [PMID: 33023650 PMCID: PMC7539454 DOI: 10.1186/s13059-020-02161-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 09/02/2020] [Indexed: 01/28/2023] Open
Abstract
Stochastic changes in DNA methylation (i.e., spontaneous epimutations) contribute to methylome diversity in plants. Here, we describe AlphaBeta, a computational method for estimating the precise rate of such stochastic events using pedigree-based DNA methylation data as input. We demonstrate how AlphaBeta can be employed to study transgenerationally heritable epimutations in clonal or sexually derived mutation accumulation lines, as well as somatic epimutations in long-lived perennials. Application of our method to published and new data reveals that spontaneous epimutations accumulate neutrally at the genome-wide scale, originate mainly during somatic development and that they can be used as a molecular clock for age-dating trees.
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Affiliation(s)
- Yadollah Shahryary
- Technical University of Munich, Department of Plant Sciences, Liesel-Beckmann-Str. 2, Freising, 85354 Germany
- Technical University of Munich, Institute for Advanced Study, Lichtenbergstr. 2a, Garching, 85748 Germany
| | - Aikaterini Symeonidi
- Technical University of Munich, Department of Plant Sciences, Liesel-Beckmann-Str. 2, Freising, 85354 Germany
| | - Rashmi R. Hazarika
- Technical University of Munich, Department of Plant Sciences, Liesel-Beckmann-Str. 2, Freising, 85354 Germany
- Technical University of Munich, Institute for Advanced Study, Lichtenbergstr. 2a, Garching, 85748 Germany
| | - Johanna Denkena
- Institute of Computational Biology, Helmholtz Zentrum München, Ingolstädter Landstr. 1, Neuherberg, 85764 Germany
| | - Talha Mubeen
- Technical University of Munich, Department of Plant Sciences, Liesel-Beckmann-Str. 2, Freising, 85354 Germany
- Technical University of Munich, Institute for Advanced Study, Lichtenbergstr. 2a, Garching, 85748 Germany
| | | | - Thomas van Gurp
- Netherlands Institute of Ecology (NIOO-KNAW), Department of Terrestrial Ecology, Wageningen, Wageningen, The Netherlands
| | - Maria Colomé-Tatché
- Institute of Computational Biology, Helmholtz Zentrum München, Ingolstädter Landstr. 1, Neuherberg, 85764 Germany
- European Research Institute for the Biology of Ageing, University of Groningen, University Medical Centre Groningen, A. Deusinglaan 1, Groningen, 9713 AV Netherlands
- TUM School of Life Sciences Weihenstephan, Technical University of Munich, Emil-Erlenmeyer-Forum 2, Freising, 85354 Germany
| | - Koen J.F. Verhoeven
- Netherlands Institute of Ecology (NIOO-KNAW), Department of Terrestrial Ecology, Wageningen, Wageningen, The Netherlands
| | - Gerald Tuskan
- The Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, USA
| | - Robert J. Schmitz
- Technical University of Munich, Institute for Advanced Study, Lichtenbergstr. 2a, Garching, 85748 Germany
- Department of Genetics, The University of Georgia, 120 East Green Street, Athens, 30602 USA
| | - Frank Johannes
- Technical University of Munich, Department of Plant Sciences, Liesel-Beckmann-Str. 2, Freising, 85354 Germany
- Technical University of Munich, Institute for Advanced Study, Lichtenbergstr. 2a, Garching, 85748 Germany
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20
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Cortijo S, Locke JCW. Does Gene Expression Noise Play a Functional Role in Plants? TRENDS IN PLANT SCIENCE 2020; 25:1041-1051. [PMID: 32467064 DOI: 10.1016/j.tplants.2020.04.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 04/22/2020] [Accepted: 04/28/2020] [Indexed: 05/20/2023]
Abstract
Gene expression in individual cells can be surprisingly noisy. In unicellular organisms this noise can be functional; for example, by allowing a subfraction of the population to prepare for environmental stress. The role of gene expression noise in multicellular organisms has, however, remained unclear. In this review, we discuss how new techniques are revealing an unexpected level of variability in gene expression between and within genetically identical plants. We describe recent progress as well as speculate on the function of transcriptional noise as a mechanism for generating functional phenotypic diversity in plants.
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Affiliation(s)
- Sandra Cortijo
- Sainsbury Laboratory, University of Cambridge, Cambridge CB2 1LR, UK
| | - James C W Locke
- Sainsbury Laboratory, University of Cambridge, Cambridge CB2 1LR, UK.
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21
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Dugé de Bernonville T, Maury S, Delaunay A, Daviaud C, Chaparro C, Tost J, O’Connor SE, Courdavault V. Developmental Methylome of the Medicinal Plant Catharanthus roseus Unravels the Tissue-Specific Control of the Monoterpene Indole Alkaloid Pathway by DNA Methylation. Int J Mol Sci 2020; 21:E6028. [PMID: 32825765 PMCID: PMC7503379 DOI: 10.3390/ijms21176028] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 08/06/2020] [Accepted: 08/18/2020] [Indexed: 02/07/2023] Open
Abstract
Catharanthus roseus produces a wide spectrum of monoterpene indole alkaloids (MIAs). MIA biosynthesis requires a tightly coordinated pathway involving more than 30 enzymatic steps that are spatio-temporally and environmentally regulated so that some MIAs specifically accumulate in restricted plant parts. The first regulatory layer involves a complex network of transcription factors from the basic Helix Loop Helix (bHLH) or AP2 families. In the present manuscript, we investigated whether an additional epigenetic layer could control the organ-, developmental- and environmental-specificity of MIA accumulation. We used Whole-Genome Bisulfite Sequencing (WGBS) together with RNA-seq to identify differentially methylated and expressed genes among nine samples reflecting different plant organs and experimental conditions. Tissue specific gene expression was associated with specific methylation signatures depending on cytosine contexts and gene parts. Some genes encoding key enzymatic steps from the MIA pathway were found to be simultaneously differentially expressed and methylated in agreement with the corresponding MIA accumulation. In addition, we found that transcription factors were strikingly concerned by DNA methylation variations. Altogether, our integrative analysis supports an epigenetic regulation of specialized metabolisms in plants and more likely targeting transcription factors which in turn may control the expression of enzyme-encoding genes.
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Affiliation(s)
- Thomas Dugé de Bernonville
- Faculté des Sciences et Techniques, Université de Tours, EA2106 Biomolécules et Biotechnologies Végétales, F-37200 Tours, France;
| | - Stéphane Maury
- INRA, EA1207 USC1328 Laboratoire de Biologie des Ligneux et des Grandes Cultures, Université d’Orléans, F-45067 Orléans, France;
| | - Alain Delaunay
- INRA, EA1207 USC1328 Laboratoire de Biologie des Ligneux et des Grandes Cultures, Université d’Orléans, F-45067 Orléans, France;
| | - Christian Daviaud
- Laboratoire Epigénétique et Environnement, LEE, Centre National de Recherche en Génomique Humaine, Institut de Biologie François Jacob, F-92265 Evry, France; (C.D.); (J.T.)
| | - Cristian Chaparro
- CNRS, IFREMER, UMR5244 Interactions Hôtes-Pathogènes-Environnments, Université de Montpellier, Université de Perpignan Via Domitia, F-66860 Perpignan, France;
| | - Jörg Tost
- Laboratoire Epigénétique et Environnement, LEE, Centre National de Recherche en Génomique Humaine, Institut de Biologie François Jacob, F-92265 Evry, France; (C.D.); (J.T.)
| | - Sarah Ellen O’Connor
- Max Planck Institute for Chemical Ecology, Department of Natural Product Biosynthesis, 07745 Jena, Germany;
| | - Vincent Courdavault
- Faculté des Sciences et Techniques, Université de Tours, EA2106 Biomolécules et Biotechnologies Végétales, F-37200 Tours, France;
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22
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Le NT, Harukawa Y, Miura S, Boer D, Kawabe A, Saze H. Epigenetic regulation of spurious transcription initiation in Arabidopsis. Nat Commun 2020; 11:3224. [PMID: 32591528 PMCID: PMC7319988 DOI: 10.1038/s41467-020-16951-w] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 06/01/2020] [Indexed: 01/01/2023] Open
Abstract
In plants, epigenetic regulation is critical for silencing transposons and maintaining proper gene expression. However, its impact on the genome-wide transcription initiation landscape remains elusive. By conducting a genome-wide analysis of transcription start sites (TSSs) using cap analysis of gene expression (CAGE) sequencing, we show that thousands of TSSs are exclusively activated in various epigenetic mutants of Arabidopsis thaliana and referred to as cryptic TSSs. Many have not been identified in previous studies, of which up to 65% are contributed by transposons. They possess similar genetic features to regular TSSs and their activation is strongly associated with the ectopic recruitment of RNAPII machinery. The activation of cryptic TSSs significantly alters transcription of nearby TSSs, including those of genes important for development and stress responses. Our study, therefore, sheds light on the role of epigenetic regulation in maintaining proper gene functions in plants by suppressing transcription from cryptic TSSs. Epigenetic regulation can silence transposons and maintain gene expression. Here the authors survey Arabidopsis mutants defective in epigenetic regulation and show ectopic activation of thousands of cryptic TSSs and altered expression of nearby genes demonstrating the importance of suppressing spurious transcription.
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Affiliation(s)
- Ngoc Tu Le
- Plant Epigenetics Unit, Okinawa Institute of Science and Technology (OIST), 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa, 904-0495, Japan
| | - Yoshiko Harukawa
- Plant Epigenetics Unit, Okinawa Institute of Science and Technology (OIST), 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa, 904-0495, Japan
| | - Saori Miura
- Plant Epigenetics Unit, Okinawa Institute of Science and Technology (OIST), 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa, 904-0495, Japan
| | - Damian Boer
- Wageningen University & Research, Droevendaalsesteeg 4, 6708 PB Wageningen, Netherlands
| | - Akira Kawabe
- Faculty of Life Sciences, Kyoto Sangyo University, Kyoto, 603-8555, Japan
| | - Hidetoshi Saze
- Plant Epigenetics Unit, Okinawa Institute of Science and Technology (OIST), 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa, 904-0495, Japan.
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23
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Leonetti P, Miesen P, van Rij RP, Pantaleo V. Viral and subviral derived small RNAs as pathogenic determinants in plants and insects. Adv Virus Res 2020; 107:1-36. [PMID: 32711727 DOI: 10.1016/bs.aivir.2020.04.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The phenotypic manifestations of disease induced by viruses and subviral infectious entities are the result of complex molecular interactions between host and viral factors. The viral determinants of the diseased phenotype have traditionally been sought at the level of structural or non-structural proteins. However, the discovery of RNA silencing mechanisms has led to speculations that determinants of the diseased phenotype are caused by viral nucleic acid sequences in addition to proteins. RNA silencing is a gene regulation mechanism conserved within eukaryotic kingdoms (with the exception of some yeast species), and in plants and insects it also functions as an antiviral mechanism. Non-coding RNAs of viral origin, ranging in size from 21 to 24 nucleotides (viral small interfering RNAs, vsiRNAs) accumulate in virus-infected tissues and organs, in some cases to comparable levels as the entire complement of host-encoded small interfering RNAs. Upon incorporation into RNA-induced silencing complexes, vsiRNAs can mediate cleavage or induce translational inhibition of nucleic acid targets in a sequence-specific manner. This review focuses on recent findings that suggest an increased complexity of small RNA-based interactions between virus and host. We mainly address plant viruses, but where applicable discuss insect viruses as well. Prominence is given to studies that have indisputably demonstrated that vsiRNAs determine diseased phenotype by either carrying sequence determinants or, indirectly, by altering host-gene regulatory pathways. Results from these studies suggest biotechnological applications, which are also discussed.
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Affiliation(s)
- Paola Leonetti
- Department of Biology, Agricultural and Food Sciences, Institute for Sustainable Plant Protection, CNR, Bari, Italy
| | - Pascal Miesen
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Ronald P van Rij
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands.
| | - Vitantonio Pantaleo
- Department of Biology, Agricultural and Food Sciences, Institute for Sustainable Plant Protection, CNR, Bari, Italy..
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24
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Seymour DK, Gaut BS. Phylogenetic Shifts in Gene Body Methylation Correlate with Gene Expression and Reflect Trait Conservation. Mol Biol Evol 2019; 37:31-43. [DOI: 10.1093/molbev/msz195] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Abstract
A subset of genes in plant genomes are labeled with DNA methylation specifically at CG residues. These genes, known as gene-body methylated (gbM), have a number of associated characteristics. They tend to have longer sequences, to be enriched for intermediate expression levels, and to be associated with slower rates of molecular evolution. Most importantly, gbM genes tend to maintain their level of DNA methylation between species, suggesting that this trait is under evolutionary constraint. Given the degree of conservation in gbM, we still know surprisingly little about its function in plant genomes or whether gbM is itself a target of selection. To address these questions, we surveyed DNA methylation across eight grass (Poaceae) species that span a gradient of genome sizes. We first established that genome size correlates with genome-wide DNA methylation levels, but less so for genic levels. We then leveraged genomic data to identify a set of 2,982 putative orthologs among the eight species and examined shifts of methylation status for each ortholog in a phylogenetic context. A total of 55% of orthologs exhibited a shift in gbM, but these shifts occurred predominantly on terminal branches, indicating that shifts in gbM are rarely conveyed over time. Finally, we found that the degree of conservation of gbM across species is associated with increased gene length, reduced rates of molecular evolution, and increased gene expression level, but reduced gene expression variation across species. Overall, these observations suggest a basis for evolutionary pressure to maintain gbM status over evolutionary time.
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Affiliation(s)
- Danelle K Seymour
- Department of Ecology and Evolutionary Biology, University of California, Irvine, Irvine, CA
- Department of Botany and Plant Sciences, University of California, Riverside, Riverside, CA
| | - Brandon S Gaut
- Department of Ecology and Evolutionary Biology, University of California, Irvine, Irvine, CA
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25
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Johannes F. DNA methylation makes mutational history. NATURE PLANTS 2019; 5:772-773. [PMID: 31358963 DOI: 10.1038/s41477-019-0491-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Affiliation(s)
- Frank Johannes
- Department of Plant Sciences, Technical University of Munich, Freising, Germany.
- Institute for Advanced Study, Technical University of Munich, Garching, Germany.
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26
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Berbel-Filho WM, Rodríguez-Barreto D, Berry N, Garcia De Leaniz C, Consuegra S. Contrasting DNA methylation responses of inbred fish lines to different rearing environments. Epigenetics 2019; 14:939-948. [PMID: 31144573 DOI: 10.1080/15592294.2019.1625674] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Epigenetic mechanisms generate plastic phenotypes that can become locally adapted across environments. Disentangling genomic from epigenomic variation is challenging in sexual species due to genetic variation among individuals, but it is easier in self-fertilizing species. We analysed DNA methylation patterns of two highly inbred strains of a naturally self-fertilizing fish reared in two contrasting environments to investigate the obligatory (genotype-dependent), facilitated (partially depend on the genotype) or pure (genotype-independent) nature of the epigenetic variation. We found higher methylation differentiation between genotypes than between environments. Most methylation differences between environments common to both strains followed a pattern where the two genotypes (inbred lines) responded to the same environmental context with contrasting DNA methylation levels (facilitated epialleles). Our findings suggest that, at least in part, DNA methylation could depend on the dynamic interaction between the genotype and the environment, which could explain the plasticity of epigenetically mediated phenotypes.
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Affiliation(s)
| | | | - Nikita Berry
- a Department of Biosciences, Swansea University , Swansea , UK
| | | | - Sofia Consuegra
- a Department of Biosciences, Swansea University , Swansea , UK
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