The present invention is transgenic chickens obtained from long-term
cultures of avian PGCs and techniques to produce and transgenic birds
derived from prolonged PGC cultures. In some embodiments, these PGCs can
be transfected with genetic constructs to modify the DNA of the PGC,
specifically to introduce a transgene encoding an exogenous protein. When
combined with a host avian embryo by known procedures, those modified
PGCs are transmitted through the germline to yield transgenic offspring.
This invention includes compositions comprising long-term cultures of
PGCs that can be genetically modified by gene targeting, that can accept
large amounts of foreign DNA and that contribute to the germline of
recipient embryos.