METHODS FOR PRODUCING TRANSGENIC LARGE MAMMALS

A transgenic large mammal is produced by a method including the steps of obtaining one or more early embryos, selectively preparing an embryo having at least three cells, and preferably at a stage in development corresponding in time to the onset of transcription of the embryo's paternal genome, and introducing isolated nucleic acid molecules into a blastomere of the selected embryo. The introduction of isolated nucleic acid molecules into such embryos results in the generation of transgenic large mammals at a significantly increased frequency as compared to introducing isolated nucleic acid molecules into zygotes or into the blastomeres of embryos at the one or two cell stage of development.