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Shan S, Gitzendanner MA, Boatwright JL, Spoelhof JP, Ethridge CL, Ji L, Liu X, Soltis PS, Schmitz RJ, Soltis DE. Genome-wide DNA methylation dynamics following recent polyploidy in the allotetraploid Tragopogon miscellus (Asteraceae). New Phytol 2024; 242:1363-1376. [PMID: 38450804 DOI: 10.1111/nph.19655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Accepted: 01/15/2024] [Indexed: 03/08/2024]
Abstract
Polyploidy is an important evolutionary force, yet epigenetic mechanisms, such as DNA methylation, that regulate genome-wide expression of duplicated genes remain largely unknown. Here, we use Tragopogon (Asteraceae) as a model system to discover patterns and temporal dynamics of DNA methylation in recently formed polyploids. The naturally occurring allotetraploid Tragopogon miscellus formed in the last 95-100 yr from parental diploids Tragopogon dubius and T. pratensis. We profiled the DNA methylomes of these three species using whole-genome bisulfite sequencing. Genome-wide methylation levels in T. miscellus were intermediate between its diploid parents. However, nonadditive CG and CHG methylation occurred in transposable elements (TEs), with variation among TE types. Most differentially methylated regions (DMRs) showed parental legacy, but some novel DMRs were detected in the polyploid. Differentially methylated genes (DMGs) were also identified and characterized. This study provides the first assessment of both overall and locus-specific patterns of DNA methylation in a recent natural allopolyploid and shows that novel methylation variants can be generated rapidly after polyploid formation. Together, these results demonstrate that mechanisms to regulate duplicate gene expression may arise soon after allopolyploid formation and that these mechanisms vary among genes.
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Affiliation(s)
- Shengchen Shan
- Florida Museum of Natural History, University of Florida, Gainesville, FL, 32611, USA
| | | | - J Lucas Boatwright
- Advanced Plant Technology Program, Clemson University, Clemson, SC, 29634, USA
| | - Jonathan P Spoelhof
- Florida Museum of Natural History, University of Florida, Gainesville, FL, 32611, USA
| | | | - Lexiang Ji
- Institute of Bioinformatics, University of Georgia, Athens, GA, 30602, USA
| | - Xiaoxian Liu
- Florida Museum of Natural History, University of Florida, Gainesville, FL, 32611, USA
- Department of Biology, University of Florida, Gainesville, FL, 32611, USA
- Bioinformatics Core, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL, 33612, USA
| | - Pamela S Soltis
- Florida Museum of Natural History, University of Florida, Gainesville, FL, 32611, USA
- Biodiversity Institute, University of Florida, Gainesville, FL, 32611, USA
- Genetics Institute, University of Florida, Gainesville, FL, 32610, USA
| | - Robert J Schmitz
- Department of Genetics, University of Georgia, Athens, GA, 30602, USA
| | - Douglas E Soltis
- Florida Museum of Natural History, University of Florida, Gainesville, FL, 32611, USA
- Department of Biology, University of Florida, Gainesville, FL, 32611, USA
- Biodiversity Institute, University of Florida, Gainesville, FL, 32611, USA
- Genetics Institute, University of Florida, Gainesville, FL, 32610, USA
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Yoo MJ, Koh J, Boatwright JL, Soltis DE, Soltis PS, Barbazuk WB, Chen S. Investigation of regulatory divergence between homoeologs in the recently formed allopolyploids, Tragopogon mirus and T. miscellus (Asteraceae). Plant J 2024; 117:1191-1205. [PMID: 37997015 DOI: 10.1111/tpj.16553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 10/02/2023] [Accepted: 11/06/2023] [Indexed: 11/25/2023]
Abstract
Polyploidy is an important evolutionary process throughout eukaryotes, particularly in flowering plants. Duplicated gene pairs (homoeologs) in allopolyploids provide additional genetic resources for changes in molecular, biochemical, and physiological mechanisms that result in evolutionary novelty. Therefore, understanding how divergent genomes and their regulatory networks reconcile is vital for unraveling the role of polyploidy in plant evolution. Here, we compared the leaf transcriptomes of recently formed natural allotetraploids (Tragopogon mirus and T. miscellus) and their diploid parents (T. porrifolius X T. dubius and T. pratensis X T. dubius, respectively). Analysis of 35 400 expressed loci showed a significantly higher level of transcriptomic additivity compared to old polyploids; only 22% were non-additively expressed in the polyploids, with 5.9% exhibiting transgressive expression (lower or higher expression in the polyploids than in the diploid parents). Among approximately 7400 common orthologous regions (COREs), most loci in both allopolyploids exhibited expression patterns that were vertically inherited from their diploid parents. However, 18% and 20.3% of the loci showed novel expression bias patterns in T. mirus and T. miscellus, respectively. The expression changes of 1500 COREs were explained by cis-regulatory divergence (the condition in which the two parental subgenomes do not interact) between the diploid parents, whereas only about 423 and 461 of the gene expression changes represent trans-effects (the two parental subgenomes interact) in T. mirus and T. miscellus, respectively. The low degree of both non-additivity and trans-effects on gene expression may present the ongoing evolutionary processes of the newly formed Tragopogon polyploids (~80-90 years).
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Affiliation(s)
- Mi-Jeong Yoo
- Department of Biology, Clarkson University, Potsdam, New York, 13699, USA
| | - Jin Koh
- Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, Florida, 32610, USA
| | - J Lucas Boatwright
- Plant and Environmental Science Department, Clemson University, Clemson, South Carolina, 29634, USA
| | - Douglas E Soltis
- Department of Biology, University of Florida, Gainesville, Florida, 32611, USA
- Genetics Institute, University of Florida, Gainesville, Florida, 32610, USA
- Biodiversity Institute, University of Florida, Gainesville, Florida, 32611, USA
- Florida Museum of Natural History, University of Florida, Gainesville, Florida, 32611, USA
| | - Pamela S Soltis
- Genetics Institute, University of Florida, Gainesville, Florida, 32610, USA
- Biodiversity Institute, University of Florida, Gainesville, Florida, 32611, USA
- Florida Museum of Natural History, University of Florida, Gainesville, Florida, 32611, USA
| | - W Brad Barbazuk
- Department of Biology, University of Florida, Gainesville, Florida, 32611, USA
- Genetics Institute, University of Florida, Gainesville, Florida, 32610, USA
| | - Sixue Chen
- Department of Biology, University of Mississippi, Oxford, Mississippi, 38677, USA
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