Sterilization of Chicken Primordial Germ Cells

It is important to introduce exogenous genes into germ cells for making transgenic bird efficiently. Primordial germ cells (PGCs) are the progenitor cells for the gametes. If PGCs that have been transfected in vitro are efficiently migrated into the gonads of recipient birds, transgenic progeny call be easily obtained. This is enhanced by depletion of recipient PGCs prior to the transfer of transfected PGCs. By now several methods have been reported to deplete endogenous PGCs, though efficiency of each methods is not directly compared. Avian PGCs are located in the central region of area pellucida in the blastodermal stage of embryo and sensitive to irradiation of X ray or ultraviolet (UV). We have compared methods using UV, gamma irradiation, and removal of cells from the center of area pellucida to reduce the number of PGCs in chicken embryos. By careful depletion of the cells of area pellucida, we have obtained a high depletion efficiency of PGCs with relatively low damage to embryos.