Development and differentiation of multicellular organisms can be regarded as the dynamic transition process of epigenomic status. In this project, we will study the molecular functions of the proteins and small non-coding RNA in the establishment of epigenetic status of early embryogenesis and development of germ cells. These two important biological events are critically important events in epigenetic research, because dynamic transition of epigenome occurs during the processes. Although mouse system is utilized in our project, fundamental mechanisms of the establishment of epigenome are same in rodents and human. Our major goals are the molecular understanding of the epigenome establishment and the development of novel methods regulating epigenetic status.