Ectopic application of the repressive histone modification H3K9me2 establishes post-zygotic reproductive isolation in Arabidopsis thaliana
- Hua Jiang1,
- Jordi Moreno-Romero1,
- Juan Santos-González1,
- Geert De Jaeger2,3,
- Kris Gevaert4,5,
- Eveline Van De Slijke2,3 and
- Claudia Köhler1
- 1Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences, Linnean Center of Plant Biology, Uppsala 75007, Sweden;
- 2Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent 9052, Belgium;
- 3VIB Center for Plant Systems Biology, Ghent 9052, Belgium;
- 4Department of Biochemistry, Ghent University, Ghent 9052, Belgium;
- 5VIB Center for Medical Biotechnology, Ghent 9052, Belgium
- Corresponding author: claudia.kohler{at}slu.se
Abstract
Hybrid seed lethality as a consequence of interspecies or interploidy hybridizations is a major mechanism of reproductive isolation in plants. This mechanism is manifested in the endosperm, a dosage-sensitive tissue supporting embryo growth. Deregulated expression of imprinted genes such as ADMETOS (ADM) underpin the interploidy hybridization barrier in Arabidopsis thaliana; however, the mechanisms of their action remained unknown. In this study, we show that ADM interacts with the AT hook domain protein AHL10 and the SET domain-containing SU(VAR)3–9 homolog SUVH9 and ectopically recruits the heterochromatic mark H3K9me2 to AT-rich transposable elements (TEs), causing deregulated expression of neighboring genes. Several hybrid incompatibility genes identified in Drosophila encode for dosage-sensitive heterochromatin-interacting proteins, which has led to the suggestion that hybrid incompatibilities evolve as a consequence of interspecies divergence of selfish DNA elements and their regulation. Our data show that imbalance of dosage-sensitive chromatin regulators underpins the barrier to interploidy hybridization in Arabidopsis, suggesting that reproductive isolation as a consequence of epigenetic regulation of TEs is a conserved feature in animals and plants.
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Footnotes
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Supplemental material is available for this article.
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Article published online ahead of print. Article and publication date are online at http://www.genesdev.org/cgi/doi/10.1101/gad.299347.117.
- Received March 24, 2017.
- Accepted June 27, 2017.
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