Appearance of Primordial Germ Cells in Young Chick Blastoderms Cultured in vitro

Abstract
Appearance of primordial germ cells (PGC) in young chick [Gallus gallus domesticus] blastoderms was investigated by the cultivation of only the epiblast or hypoblast. Presumptive PGC exist in the epiblast before primitive streak formation. They translocate gradually to the lower layer during early stages of primitive streak formation, though substantial number of presumptive PGC remain in the upper layer. The existing primary hypoblast under the epiblast is dispensable for the further differentiation of the PGC.