ABSTRACT
Modification of the mouse germline traditionally has been achieved in two ways, introduction of DNA into a fertilized egg or into embryonic stem (ES) cells that can contribute to the germline of a chimeric mouse produced by injection of the altered ES cells into a host embryo. Primordial germ cells (PGCs) and oogonia from female embryos can be transferred into the ovarian sac of an adult animal into fertilizable oocytes that give rise to offspring. Following a brief description of germ cell development in the mouse, this chapter describes techniques for isolating and culturing PGCs. Advances in PGC isolation and culture techniques may provide the opportunity to manipulate these PGCs in vitro while retaining their ability to populate the germline. Initial studies suggest that introduction and expression of cloned DNA into Embryonic germ (EG) cell lines is likely to be more straightforward than into PGCs. EG cells may prove useful in overcoming some of the limitations encountered using ES cells.
