Biology Department Seminar

DNA methylation is an epigenetic modification that plays critical roles in gene silencing, development and the maintenance of genome integrity in most eukaryotic organisms. In Arabidopsis thaliana, DNA methylation is targeted by small RNAs through an important, but as yet poorly understood pathway termed RNA-directed DNA methylation (RdDM). To better understand this process I developed several biochemical methods, mainly utilizing epitope tagging, affinity purification, and mass spectrometry, enabling me to isolate two protein complexes critical for RdDM. My characterization of these complexes led to the discovery of several new RdDM factors and to the placement of known RdDM factors within current models, filling key gaps in our understanding of this critical epigenetic process. While studying the pathways controlling the establishment and maintenance of DNA methylation, I became interested in understanding the mechanisms through which epigenetic modifications are translated into stable expression states—a poorly understood process that will be the focus of my future research.