HHMI Investigator, Professor
The Johns Hopkins University, Department of Biology
Abstract: We found that during asymmetric division of stem cells, preexisting old histones are selectively retained in the stem cell, whereas newly synthesized histones are enriched in the daughter cell that is committed to differentiation. This process provides an important mechanism that allows the two daughter cells to each inherit different epigenetic information from a single cell division. These intriguing findings urge us to better understand how cells maintain their epigenetic memories or reset their epigenome. We found that the mechanism and readout of asymmetric histone inheritance involve at least three-steps, wherein old and new histones are asymmetrically incorporated during DNA replication (Step 1) and are segregated in a biased manner during mitosis (Step 2), driving differential inheritance of key factors to regulate distinct cellular events in the resulting daughter cells (Step 3). We have developed new tools and methods to explore the molecular and cellular mechanisms. Recently, we studied this phenomenon in multiple systems across species and identified conserved mode of histone inheritance. I will discuss the updated information regarding the biological significance and generality of asymmetric histone inheritance in multicellular organisms.
Bio: Dr. Chen is an HHMI Investigator and a Professor of the Department of Biology at the Johns Hopkins University. Dr. Chen joined the Department of Biology at Johns Hopkins in 2008. Her current research focuses on the epigenetic regulation in adult stem cell lineages. Her studies have led to the discovery that epigenetic information is asymmetrically inherited in stem cells. Furthermore, Dr. Chen’s recent studies illuminate that both DNA replication and mitotic cell division contribute to establishing and partitioning such an epigenetic asymmetry. Dr. Chen received her Ph.D. in Molecular Cell & Developmental Biology from University of Texas at Austin (Drosophila eye development research). She was a postdoctoral fellow in the laboratory of Dr. Margaret Fuller at Stanford University School of Medicine, where she focused on how tissue-specific transcription factors regulate robust transcription of differentiation genes in germ cells.