Seminars

Epigenetic modifications are important for transcriptional control in eukaryotes. One such modification, DNA methylation, is extensively reprogrammed to regulate animal development. However, we are only beginning to understand the changes in methylation during the development of plants and the importance of these changes for cell function.
Our lab has uncovered a distinctive DNA methylation signature specific to the entire male sexual lineage of the flowering plant Arabidopsis thaliana, and we demonstrate that this sexual-lineage-specific reprogramming is mediated by the de novo RNA-directed DNA methylation (RdDM) pathway. RdDM typically associates with transposons, and we show that in the male sexual lineage it is modulated to target genes as well. We further establish that this gene-targeted RdDM activity is important for the regulation of gene expression and splicing in meiocytes, and is required for normal meiosis.
I am now carrying out research to determine if these methylation patterns are conserved in other land plant species or whether there is a variety of DNA methylation reprogramming events during the sexual development of plants. My specific focus is on the basal land plant Marchantia polymorpha, and preliminary data suggest that gene-targeted methylation and animal-like methylation patterns can be observed at different stages of sexual development in this species.

Walker, J., Gao, H., Zhang, J., Aldridge, B., Vickers, M., Higgins, J.D. and Feng, X., 2018. Sexual-lineage-specific DNA methylation regulates meiosis in Arabidopsis. Nature Genetics, 50(1), p.130-137.