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Guerrero L, Bay R. Patterns of methylation and transcriptional plasticity during thermal acclimation in a reef-building coral. Evol Appl 2024; 17:e13757. [PMID: 39027686 PMCID: PMC11254580 DOI: 10.1111/eva.13757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 06/21/2024] [Accepted: 06/29/2024] [Indexed: 07/20/2024] Open
Abstract
Phenotypic plasticity can buffer organisms against short-term environmental fluctuations. For example, previous exposure to increased temperatures can increase thermal tolerance in many species. Prior studies have found that acclimation to higher temperature can influence the magnitude of transcriptional response to subsequent acute thermal stress (hereafter, "transcriptional response modulation"). However, mechanisms mediating this gene expression response and, ultimately, phenotypic plasticity remain largely unknown. Epigenetic modifications are good candidates for modulating transcriptional response, as they broadly correlate with gene expression. Here, we investigate changes in DNA methylation as a possible mechanism controlling shifts in gene expression plasticity and thermal acclimation in the reef-building coral Acropora nana. We find that gene expression response to acute stress is altered in corals acclimated to different temperatures, with many genes exhibiting a dampened response to heat stress in corals pre-conditioned to higher temperatures. At the same time, we observe shifts in methylation during both acclimation (11 days) and acute heat stress (24 h). We observed that the acute heat stress results in shifts in gene-level methylation and elicits an acute transcriptional response in distinct gene sets. Further, acclimation-induced shifts in gene expression plasticity and differential methylation also largely occur in separate sets of genes. Counter to our initial hypothesis no overall correlation between the magnitude of differential methylation and the change in gene expression plasticity. We do find a small but statistically significant overlap in genes exhibiting both dampened expression response and shifts in methylation (14 genes), which could be candidates for further inquiry. Overall, our results suggest transcriptional response modulation occurs independently from methylation changes induced by thermal acclimation.
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Affiliation(s)
| | - Rachael Bay
- University of California, DavisDavisCaliforniaUSA
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2
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Song Y, Peng Y, Liu L, Li G, Zhao X, Wang X, Cao S, Muyle A, Zhou Y, Zhou H. Phased gap-free genome assembly of octoploid cultivated strawberry illustrates the genetic and epigenetic divergence among subgenomes. HORTICULTURE RESEARCH 2024; 11:uhad252. [PMID: 38269295 PMCID: PMC10807706 DOI: 10.1093/hr/uhad252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Accepted: 11/18/2023] [Indexed: 01/26/2024]
Abstract
The genetic and epigenetic mechanisms underlying the coexistence and coordination of the four diverged subgenomes (ABCD) in octoploid strawberries (Fragaria × ananassa) remains poorly understood. In this study, we have assembled a haplotype-phased gap-free octoploid genome for the strawberry, which allowed us to uncover the sequence, structure, and epigenetic divergences among the subgenomes. The diploid progenitors of the octoploid strawberry, apart from subgenome A (Fragaria vesca), have been a subject of public controversy. Phylogenomic analyses revealed a close relationship between diploid species Fragaria iinumae and subgenomes B, C, and D. Subgenome A, closely related to F. vesca, retains the highest number of genes, exhibits the lowest content of transposable elements (TEs), experiences the strongest purifying selection, shows the lowest DNA methylation levels, and displays the highest expression level compared to the other three subgenomes. Transcriptome and DNA methylome analyses revealed that subgenome A-biased genes were enriched in fruit development biological processes. In contrast, although subgenomes B, C, and D contain equivalent amounts of repetitive sequences, they exhibit diverged methylation levels, particularly for TEs located near genes. Taken together, our findings provide valuable insights into the evolutionary patterns of subgenome structure, divergence and epigenetic dynamics in octoploid strawberries, which could be utilized in strawberry genetics and breeding research.
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Affiliation(s)
- Yanhong Song
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou, 450009, China
| | - Yanling Peng
- National Key Laboratory of Tropical Crop Breeding, Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Key Laboratory of Synthetic Biology, Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen 518120, China
| | - Lifeng Liu
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou, 450009, China
| | - Gang Li
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou, 450009, China
| | - Xia Zhao
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou, 450009, China
| | - Xu Wang
- National Key Laboratory of Tropical Crop Breeding, Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Key Laboratory of Synthetic Biology, Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen 518120, China
| | - Shuo Cao
- National Key Laboratory of Tropical Crop Breeding, Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Key Laboratory of Synthetic Biology, Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen 518120, China
| | - Aline Muyle
- CEFE, University of Montpellier, CNRS, EPHE, IRD, Montpellier 34000, France
| | - Yongfeng Zhou
- National Key Laboratory of Tropical Crop Breeding, Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Key Laboratory of Synthetic Biology, Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen 518120, China
- National Key Laboratory of Tropical Crop Breeding, Tropical Crops Genetic Resources Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou 570000, China
| | - Houcheng Zhou
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou, 450009, China
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3
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Briffa A, Hollwey E, Shahzad Z, Moore JD, Lyons DB, Howard M, Zilberman D. Millennia-long epigenetic fluctuations generate intragenic DNA methylation variance in Arabidopsis populations. Cell Syst 2023; 14:953-967.e17. [PMID: 37944515 DOI: 10.1016/j.cels.2023.10.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 07/18/2023] [Accepted: 10/13/2023] [Indexed: 11/12/2023]
Abstract
Methylation of CG dinucleotides (mCGs), which regulates eukaryotic genome functions, is epigenetically propagated by Dnmt1/MET1 methyltransferases. How mCG is established and transmitted across generations despite imperfect enzyme fidelity is unclear. Whether mCG variation in natural populations is governed by genetic or epigenetic inheritance also remains mysterious. Here, we show that MET1 de novo activity, which is enhanced by existing proximate methylation, seeds and stabilizes mCG in Arabidopsis thaliana genes. MET1 activity is restricted by active demethylation and suppressed by histone variant H2A.Z, producing localized mCG patterns. Based on these observations, we develop a stochastic mathematical model that precisely recapitulates mCG inheritance dynamics and predicts intragenic mCG patterns and their population-scale variation given only CG site spacing. Our results demonstrate that intragenic mCG establishment, inheritance, and variance constitute a unified epigenetic process, revealing that intragenic mCG undergoes large, millennia-long epigenetic fluctuations and can therefore mediate evolution on this timescale.
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Affiliation(s)
- Amy Briffa
- Department of Computational and Systems Biology, John Innes Centre, Norwich NR4 7UH, UK
| | - Elizabeth Hollwey
- Department of Cell and Developmental Biology, John Innes Centre, Norwich NR4 7UH, UK; Institute of Science and Technology, 3400 Klosterneuburg, Austria
| | - Zaigham Shahzad
- Department of Cell and Developmental Biology, John Innes Centre, Norwich NR4 7UH, UK; Department of Life Sciences, Syed Babar Ali School of Science and Engineering, Lahore University of Management Sciences, Lahore, Pakistan
| | - Jonathan D Moore
- Department of Cell and Developmental Biology, John Innes Centre, Norwich NR4 7UH, UK
| | - David B Lyons
- Department of Cell and Developmental Biology, John Innes Centre, Norwich NR4 7UH, UK
| | - Martin Howard
- Department of Computational and Systems Biology, John Innes Centre, Norwich NR4 7UH, UK.
| | - Daniel Zilberman
- Department of Cell and Developmental Biology, John Innes Centre, Norwich NR4 7UH, UK; Institute of Science and Technology, 3400 Klosterneuburg, Austria.
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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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Li M, Ou M, He X, Ye H, Ma J, Liu H, Yang H, Zhao P. DNA methylation role in subgenome expression dominance of Juglans regia and its wild relative J. mandshurica. PLANT PHYSIOLOGY 2023; 193:1313-1329. [PMID: 37403190 DOI: 10.1093/plphys/kiad394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 06/07/2023] [Accepted: 06/12/2023] [Indexed: 07/06/2023]
Abstract
Subgenome expression dominance plays a crucial role in the environmental adaptation of polyploids. However, the epigenetic molecular mechanism underlying this process has not been thoroughly investigated, particularly in perennial woody plants. Persian walnut (Juglans regia) and its wild relative, Manchurian walnut (Juglans mandshurica), are woody plants of great economic importance and are both paleopolyploids that have undergone whole-genome duplication events. In this study, we explored the characteristics of subgenome expression dominance in these 2 Juglans species and examined its epigenetic basis. We divided their genomes into dominant subgenome (DS) and submissive subgenome (SS) and found that the DS-specific genes might play critical roles in biotic stress response or pathogen defense. We comprehensively elucidated the characteristics of biased gene expression, asymmetric DNA methylation, transposable elements (TEs), and alternative splicing (AS) events of homoeologous gene pairs between subgenomes. The results showed that biased expression genes (BEGs) in 2 Juglans species were mainly related to external stimuli response, while non-BEGs were related to complexes that might be involved in signal transduction. DS genes had higher expression and more AS events while having less DNA methylation and TEs than homoeologous genes from the SS in the 2 Juglans species. Further studies showed that DNA methylation might contribute to the biased expression of gene pairs by modifying LTR/TIR/nonTIR TEs and improving the AS efficiency of corresponding precursor mRNAs in a particular context. Our study contributes to understanding the epigenetic basis of subgenome expression dominance and the environmental adaptation of perennial woody plants.
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Affiliation(s)
- Mengdi Li
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, Xi'an, Shaanxi 710069, China
| | - Mengwei Ou
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, Xi'an, Shaanxi 710069, China
| | - Xiaozhou He
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, Xi'an, Shaanxi 710069, China
| | - Hang Ye
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, Xi'an, Shaanxi 710069, China
| | - Jiayu Ma
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, Xi'an, Shaanxi 710069, China
| | - Hengzhao Liu
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, Xi'an, Shaanxi 710069, China
| | - Huijuan Yang
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, Xi'an, Shaanxi 710069, China
| | - Peng Zhao
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, Xi'an, Shaanxi 710069, China
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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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Cao Q, Huang L, Li J, Qu P, Tao P, Crabbe MJC, Zhang T, Qiao Q. Integrated transcriptome and methylome analyses reveal the molecular regulation of drought stress in wild strawberry (Fragaria nilgerrensis). BMC PLANT BIOLOGY 2022; 22:613. [PMID: 36575384 PMCID: PMC9795625 DOI: 10.1186/s12870-022-04006-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 12/14/2022] [Indexed: 06/17/2023]
Abstract
BACKGROUND Fragaria nilgerrensis, which is a diploid wild strawberry with excellent drought-resistance, would provide useful candidate genes for improving drought resistance of cultivated strawberry. So far, its molecular regulatory networks involved in drought stress are unclear. We therefore investigated the drought response regulatory networks of F. nilgerrensis based on the integrated analysis of DNA methylation, transcriptome and physiological traits during four time points under drought stress. RESULTS: The most differentially expressed genes and the physiological changes were found at 8 days (T8) compared with 0 day (T0, control). Methylome analysis revealed slight dynamic changes in genome-wide mC levels under drought conditions, while the most hypomethylated and hypermethylated regions were identified at T4 and T8. Association analysis of the methylome and transcriptome revealed that unexpressed genes exhibited expected hypermethylation levels in mCHG and mCHH contexts, and highly expressed genes exhibited corresponding hypomethylation levels in the gene body, but mCG contexts showed the opposite trend. Then, 835 differentially methylated and expressed genes were identified and grouped into four clustering patterns to characterize their functions. The genes with either negative or positive correlation between methylation and gene expression were mainly associated with kinases, Reactive Oxygen Species (ROS) synthesis, scavenging, and the abscisic acid (ABA) signal pathway. Consistently, weighted gene co-expression network analysis (WGCNA) revealed Hub genes including NCED, CYP707A2, PP2Cs and others that play important roles in the ABA signaling pathway. CONCLUSION F. nilgerrensis drought is dominated by ABA-dependent pathways, possibly accompanied by ABA-independent crosstalk. DNA methylation may affect gene expression, but their correlation was more subtle and multiple types of association exist. Maintaining the balance between ROS regeneration and scavenging is an important factor in drought resistance in F. nilgerrensis. These results deepen our understanding of drought resistance and its application in breeding in strawberry plants.
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Affiliation(s)
- Qiang Cao
- School of Agriculture, Yunnan University, 650091, Kunming, China
| | - Lin Huang
- School of Agriculture, Yunnan University, 650091, Kunming, China
| | - Jiamin Li
- School of Agriculture, Yunnan University, 650091, Kunming, China
| | - Peng Qu
- School of Agriculture, Yunnan University, 650091, Kunming, China
| | - Pang Tao
- Horticultural Research Institute, Yunnan Academy of Agricultural Sciences, 650205, Kunming, China
| | - M James C Crabbe
- Wolfson College, Oxford University, Oxford, OX26UD, UK
- Institute of Biomedical and Environmental Science and Technology, School of Life Sciences, University of Bedfordshire, Park Square, LU1 3JU, Luton, UK
- School of Life Science, Shanxi University, 030006, Taiyuan, Shanxi, China
| | - Ticao Zhang
- College of Chinese Material Medica, Yunnan University of Chinese Medicine, 650500, Kunming, China.
| | - Qin Qiao
- College of Horticulture and Landscape, Yunnan Agricultural University, 650201, Kunming, China.
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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: 36] [Impact Index Per Article: 18.0] [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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Yao N, Schmitz RJ, Johannes F. Epimutations Define a Fast-Ticking Molecular Clock in Plants. Trends Genet 2021; 37:699-710. [PMID: 34016450 PMCID: PMC8282728 DOI: 10.1016/j.tig.2021.04.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 04/15/2021] [Accepted: 04/16/2021] [Indexed: 12/16/2022]
Abstract
Stochastic gains and losses of DNA methylation at CG dinucleotides are a frequent occurrence in plants. These spontaneous 'epimutations' occur at a rate that is 100 000 times higher than the genetic mutation rate, are effectively neutral at the genome-wide scale, and are stably inherited across mitotic and meiotic cell divisions. Mathematical models have been extraordinarily successful at describing how epimutations accumulate in plant genomes over time, making this process one of the most predictable epigenetic phenomena to date. Here, we propose that their high rate and effective neutrality make epimutations a powerful new molecular clock for timing evolutionary events of the recent past and for age dating of long-lived perennials such as trees.
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Affiliation(s)
- Nan Yao
- Department of Genetics, University of Georgia, Athens, GA, USA
| | - Robert J Schmitz
- Department of Genetics, University of Georgia, Athens, GA, USA; Institute for Advanced Study, Technical University of Munich, Garching, Germany
| | - Frank Johannes
- Institute for Advanced Study, Technical University of Munich, Garching, Germany; Population Epigenetics and Epigenomics, Technical University of Munich, Freising, Germany.
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