Transgenic birds by DNA microinjection.

We have developed a method for production of transgenic chickens by DNA microinjection of chick zygotes followed by ex vivo embryo culture. The fate of plasmid DNA microinjected into the germinal disc of zygotes was analyzed in embryos which survived for at least 12 days in culture. Approximately half of the embryos contained plasmid DNA, 6% at a level equivalent to one copy per cell in all tissues analyzed. Seven chicks, 5.5% of the total number of injected ova, survived to sexual maturity. One of these, a cockerel, transmitted the exogenous DNA to 3.4% of his offspring. These G1 birds have reached sexual maturity and have been bred to produce transgenic offspring, demonstrating that stable transmission of foreign DNA can be obtained by our method.