Human beta-globin gene sequences injected into mouse eggs, retained in adults, and transmitted to progeny

Foreign gene sequences were retained in two adult mice (out of 62 analyzed) from fertilized eggs injected with a recombinant plasmid containing the human beta-globin genomic region and the herpes simplex viral thymidine kinase gene. The intact human and viral genes were found in DNA of one of the animals and, in the other, at least part of the human globin gene was present. The latter individual transmitted these sequences to its progeny in a Mendelian ration. Thus, human DNA may be incorporated into the germ line of mice for in vivo studies of regulation of gene expression in development, genetic diseases, and malignancy.