Mouse oocytes derived from in vitro grown primary ovarian follicles are fertile

A model culture system has been developed whereby individual, primary ovarian mouse follicles can be grown in vitro to the Graafian stage in the normal physiological time course, and then ovulated in response to luteinizing hormone. We report here on the successful fertilization and subsequent embryo development of the oocytes from such follicles. This is the first time that oocytes from in-vitro matured whole follicles have been fertilized and shown to produce viable offspring in host animals. The study demonstrates that the culture system mimics physiological conditions for normal follicle development.