GENE-TRANSFER AND EXPRESSION IN PROGENY AFTER INTRAVENOUS DNA INJECTION INTO PREGNANT MICE

Several methods that enable foreign genes to be transferred directly i nto germ cells and adult animals have been developed(1-4), which have stimulated great interest in manipulating genes in vivo. However, ther e have been no methods available for introducing genes into fetuses. W e report here that a single intravenous injection of expression plasmi d:lipopolyamine complexes into pregnant mice resulted in successful ge ne transfer into the embryos. The transgenes thus introduced were expr essed in the fetuses and newborn progeny. This simple and new method o f gene transfer into embryos will facilitate rapid analysis of transge ne effects in the fetuses and will be useful for studying gene-deficie nt animal models to gain transgene functions at desired stages of embr yogenesis.