Stem cells and reproductive medicine.

For decades it has remained as a central dogma in dogma in reproductive biology that female mammals are born with a set non-renewable number of germ cells in the ovary. Recent revolutionary studies challenged this dogma by showing postnatal oogenesis in the adult ovary. In this review article the formation of primordial germ cells (PGC), the precursors of adult gametocytes beginning from their specification to their migration to prospective gonads will be reviewed with a special emphasis on stem cells studies that obtained gametocytes from germ and non germline stem cells.