RNA-seq analysis of in vivo- and in vitro-produced mouse oocytes

The female germline undergoes a unique line of differentiation processes that endows totipotency to the egg. During these processes, biologically significant events such as meiosis and oocyte growth are controlled in an orderly manner, with any disorder causing infertility and developmental arrest of the next generation. Reconstitution in vitro of the entire process of oogenesis from pluripotent stem cells is a key achievement in stem cell biology and regenerative medicine, but a robust and reproducible culture system has not been established. Here, we report successful reconstitution in vitro throughout the entire process of oogenesis from pluripotent stem cells, yielding in vitro-produced eggs that gave rise to healthy pups. Moreover, the pluripotent stem lines were re-derived from the in vitro-generated eggs, thereby reconstituting one generation on a dish. This culture system will provide a unique platform for elucidating the molecular mechanisms underlying totipotency and could open an avenue to producing vast numbers of eggs in vitro.