The Microinjection of DNA into Early Chicken Embryo

Manipulation of early chicken embryo became possible by developing the ex vivo embryo culture technique from single-cell stage to hatching. Microinjection of DNA into the germinal disc of fertilized ova was performed and the manipulated embryos were cultured in vitro and then in recipient eggshells. Expression of the injected DNA was observed in the embryonic and extra-embryonic tissues, but the expression pattern was mosaic. After hatching, the injected DNA was detected in the somatic and germ cells of chickens, although the efficiency of introduction of injected DNA into chickens was low. It was observed that in one of these chickens the injected DNA was integrated into the host chromosome and transmitted stably to the next generation. These results indicate that microinjection of exogenous DNA into fertilized ova is a feasible method for introducing DNA into chickens.