Origin and Development of Primordial Germ Cells

The origin and development of the precursors of gametes termed primordial germ cells (PGCs) have always fascinated the scientists. Today is largely accepted that in Mammals the germ cell lineage is specified in extraembryonic tissues and that after determination PGCs move into the embryo proper to colonize the gonadal primordia. Although the mechanisms of such processes have been partly clarified in the mouse experimental model, in humans they remain still elusive. Likewise, the epigenetic modifications and sex differentiation events accompanying PGC migration and following gonad colonization by such cells are only partly known in the mouse and little characterized in other mammalian species including humans. Here is a brief account of the main progresses that in the last about thirty years have been done in studying the cellular and molecular events of the PGC origin and development in mouse and man