Primordial germ cells (PGC) are the precursors of oocytes and spermatocytes. They are characterized by being the only ones capable of accurately retaining pluripotent developmental ability after gastrulation. These cells come from the epiblast, they differ from somatic cells by signals from the extra-embryonic ectoderm and visceral endoderm, starting from day 6.0 to 7.5 dpc in murine species. Then migrate through the primitive gut and dorsal mesentery to reach genital ridges around 10.5 dpc. The primordial germ cells have a varied morphology and gene expression therefore have different markers according to the stage where they are. Among the most studied and characterized markers are Fragilis, c-Kit, Stella, DAZ, Vasa, GCNA1, Blimp1 and SSEA-1.