Isolation of chick primordial germ cells from stages 4-8 embryos.

Chick embryo primordial germ cells (PGCs) stages 4-8 were manually isolated for the first time from the late hypoblast layer. They were confirmed to be PGCs by periodic acid-Schiff (PAS) staining and examination by scanning electron microscopy (SEM). They were subsequently introduced onto a variety of artificial substrata. On two dimensional substrata, the cells change from a spherical shape covered with numerous microvilli to a rounded cell with a "skirt" of cytoplasm. Eventually a process projects from one side of the smooth cell. On a three dimensional substrate the PGCs change from a spherical shape covered with numerous microvilli to a smooth surfaced cell with a long single process. It is concluded that the PGCs which are originally spherical in situ in stage 4 alter their morphology both in vivo during their migration and in vitro studies.