Derivation of germ cells from embryonic stem cells.

Embryonic stem cells (ESCs), derivatives of cells of early mammalian embryos, have proven to be one of the most powerful tools in developmental and stem cell biology. When injected into embryos, ESCs can contribute to tissues derived from all three germ layers and to the germline. Prior studies have successfully shown that ESCs can recapitulate features of embryonic development by spontaneously forming somatic lineages in culture. Amazingly, recently it has been shown that mouse ESCs can also give rise to primordial germ cells (PGCs) in culture that are capable of undergoing meiosis and forming both male and female gametes. While the full potential of these ES-derived germ cells and gametes remains to be demonstrated, these discoveries provide a new approach for studying reproductive biology and medicine.