--- res: bibo_abstract: - Epigenetic reprogramming is required for proper regulation of gene expression in eukaryotic organisms. In Arabidopsis, active DNA demethylation is crucial for seed viability, pollen function, and successful reproduction. The DEMETER (DME) DNA glycosylase initiates localized DNA demethylation in vegetative and central cells, so-called companion cells that are adjacent to sperm and egg gametes, respectively. In rice, the central cell genome displays local DNA hypomethylation, suggesting that active DNA demethylation also occurs in rice; however, the enzyme responsible for this process is unknown. One candidate is the rice REPRESSOR OF SILENCING 1a (ROS1a) gene, which is related to DME and is essential for rice seed viability and pollen function. Here, we report genome-wide analyses of DNA methylation in wild-type and ros1a mutant sperm and vegetative cells. We find that the rice vegetative cell genome is locally hypomethylated compared with sperm by a process that requires ROS1a activity. We show that many ROS1a target sequences in the vegetative cell are hypomethylated in the rice central cell, suggesting that ROS1a also demethylates the central cell genome. Similar to Arabidopsis, we show that sperm non-CG methylation is indirectly promoted by DNA demethylation in the vegetative cell. These results reveal that DNA glycosylase-mediated DNA demethylation processes are conserved in Arabidopsis and rice, plant species that diverged 150 million years ago. Finally, although global non-CG methylation levels of sperm and egg differ, the maternal and paternal embryo genomes show similar non-CG methylation levels, suggesting that rice gamete genomes undergo dynamic DNA methylation reprogramming after cell fusion.@eng bibo_authorlist: - foaf_Person: foaf_givenName: M. Yvonne foaf_name: Kim, M. Yvonne foaf_surname: Kim - foaf_Person: foaf_givenName: Akemi foaf_name: Ono, Akemi foaf_surname: Ono - foaf_Person: foaf_givenName: Stefan foaf_name: Scholten, Stefan foaf_surname: Scholten - foaf_Person: foaf_givenName: Tetsu foaf_name: Kinoshita, Tetsu foaf_surname: Kinoshita - foaf_Person: foaf_givenName: Daniel foaf_name: Zilberman, Daniel foaf_surname: Zilberman foaf_workInfoHomepage: http://www.librecat.org/personId=6973db13-dd5f-11ea-814e-b3e5455e9ed1 orcid: 0000-0002-0123-8649 - foaf_Person: foaf_givenName: Takashi foaf_name: Okamoto, Takashi foaf_surname: Okamoto - foaf_Person: foaf_givenName: Robert L. foaf_name: Fischer, Robert L. foaf_surname: Fischer bibo_doi: 10.1073/pnas.1821435116 bibo_issue: '19' bibo_volume: 116 dct_date: 2019^xs_gYear dct_isPartOf: - http://id.crossref.org/issn/0027-8424 - http://id.crossref.org/issn/1091-6490 dct_language: eng dct_publisher: National Academy of Sciences@ dct_subject: - Multidisciplinary dct_title: DNA demethylation by ROS1a in rice vegetative cells promotes methylation in sperm@ fabio_hasPubmedId: '31000601' ...