Loss of CG methylation in Marchantia polymorpha causes disorganization of cell division and reveals unique DNA methylation regulatory mechanisms of non-CG methylation

Ikeda, Y., Nishihama, R., Yamaoka, S., Arteaga-Vazquez, M. A., Aguilar-Cruz, A., Grimanelli, D., Pogorelcnik, R., Martienssen, R. A., Yamato, K. T., Kohchi, T., Hirayama, T., Mathieu, O. (August 2018) Loss of CG methylation in Marchantia polymorpha causes disorganization of cell division and reveals unique DNA methylation regulatory mechanisms of non-CG methylation. Plant Cell Physiol, 59 (12). pp. 2421-2431. ISSN 0032-0781

URL: https://www.ncbi.nlm.nih.gov/pubmed/30102384
DOI: 10.1093/pcp/pcy161

Abstract

DNA methylation is an epigenetic mark that ensures silencing of transposable elements (TEs) and affects gene expression in many organisms. The function of different DNA methylation regulatory pathways has been largely characterized in the model plant Arabidopsis thaliana. However, far less is known about DNA methylation regulation and functions in basal land plants. Here we focus on the liverwort Marchantia polymorpha, an emerging model species that represents a basal lineage of land plants. We identified MpMET, the M. polymorpha orthologue of the METHYLTRANSFERASE 1 (MET1) gene required for maintenance of methylation at CG sites in angiosperms. We generated Mpmet mutants using the CRISPR/Cas9 system, which showed a significant loss of CG methylation and severe morphological changes and developmental defects. The mutants developed many adventitious shoot-like structures, suggesting that MpMET is required for maintaining differentiated cellular identities in the gametophyte. Even though numerous TEs were up-regulated, non-CG methylation was generally highly increased at TEs in the Mpmet mutants. Closer inspection of CHG methylation revealed features unique to M. polymorpha. Methylation of CCG sites in M. polymorpha does not depend on MET1, unlike in A. thaliana and Physcomitrella patens. Furthermore, unlike A. thaliana, M. polymorpha shows higher methylation level at CAG sites than at other CHG contexts and CAG/CTG sites are mostly methylated asymmetrically. Interestingly, CAG and CTG methylation reached comparable levels and symmetry upon loss of CG methylation. Our results highlight the diversity of non-CG methylation regulatory mechanisms in plants.

Item Type: Paper
Subjects: bioinformatics > genomics and proteomics > genetics & nucleic acid processing > DNA, RNA structure, function, modification > DNA methylation
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > methyltransferase
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > plant proteins
CSHL Authors:
Communities: CSHL labs > Martienssen lab
Depositing User: Matthew Dunn
Date: 9 August 2018
Date Deposited: 15 Aug 2018 15:56
Last Modified: 07 Jan 2019 16:15
Related URLs:
URI: http://repository.cshl.edu/id/eprint/37106

Actions (login required)

Administrator's edit/view item Administrator's edit/view item
CSHL HomeAbout CSHLResearchEducationNews & FeaturesCampus & Public EventsCareersGiving