The long-term goal of my research is to understand the mechanisms and evolution of epigenetic events during mammalian reproduction. Epigenetics is proving to be a key regulatory mechanism underlying sexual reproduction. The epigenetic program of parental germ cells is required for establishing totipotency in the early embryo and ensuring the continuity of mammalian life. Unique and heritable chromatin modifications are acquired during sperm and egg formation. During the dynamic change of the epigenome in germline, sex chromosomes go through unique epigenetic programming. Sex chromosomes have the pivotal roles in sexual reproduction, and this involves the function of genes on sex chromosomes in germ cells. One of our focus areas is epigenetic regulation of sex chromosomes in germ cell development.

During male meiosis, sex chromosomes are uniquely subject to chromosome-wide silencing. Recently, my laboratory demonstrated that DNA damage response pathways trigger epigenetic programming on the sex chromosomes in germ cells. An on-going direction of my laboratory is to pursue a general link between DNA damage response pathways and epigenetic programming. Another goal of my laboratory is to identify novel factors and related pathways that control epigenetic programming during mouse reproduction, especially focusing on the events occurring on sex chromosomes during spermatogenesis as well as the regulatory mechanisms in germline stem cells. Furthermore, we are interested in transgenerational inheritance of epigenetic information. In particular, we hope to elucidate the paternal epigenetic information that is transmitted through compacted spermatozoa to the early embryos of the next generation.

To pursue these goals, we use a multi-disciplinary approach to study germ cell development with extensive use of mouse genetics, cutting-edge cytological analysis, cell culture, and gene expression and genomic analysis using next generation sequencing techniques as well as evolutionary analysis.