Reconstitution in vitro of the entire cycle of the mouse female germ line

Using a protocol that recapitulates both meiosis and oocyte growth in vitro , the authors induce mouse pluripotent stem cells to differentiate into fully functional oocytes that can be fertilized and generate viable offspring, thereby recapitulating the full mammalian female germline cycle in a dish. A mouse female germline in vitro This study reports the successful production of functional mouse eggs entirely in culture, a long-standing goal in the fields of stem cell biology and regenerative medicine. From mouse pluripotent stem cells, the authors generated functional oocytes in vitro that can be fertilized and generate fully viable offspring. Their protocol recapitulates both meiosis and oocyte growth, and the authors are also able to isolate pluripotent stem cell lines from the in-vitro -generated eggs after fertilization, thereby recapitulating the full mammalian female germline cycle in a dish. The female germ line undergoes a unique sequence of differentiation processes that confers totipotency to the egg 1 , 2 . The reconstitution of these events in vitro using pluripotent stem cells is a key achievement in reproductive biology and regenerative medicine. Here we report successful reconstitution in vitro of the entire process of oogenesis from mouse pluripotent stem cells. Fully potent mature oocytes were generated in culture from embryonic stem cells and from induced pluripotent stem cells derived from both embryonic fibroblasts and adult tail tip fibroblasts. Moreover, pluripotent stem cell lines were re-derived from the eggs that were generated in vitro , thereby reconstituting the full female germline cycle in a dish. This culture system will provide a platform for elucidating the molecular mechanisms underlying totipotency and the production of oocytes of other mammalian species in culture.