[Characterization of human coagulation factor IX cDNA expressed in cultured cells and in transgenic mice]

Two recombinant genes containing human coagulation factor IX cDNA driven by SV40 early promoter or by mouse MT promoter were introduced into the cultured mouse fabroblasts, respectively. It was found that both of them could be expressed in the cultured cells. Then, the two recombinant genes were microinjected into the male pronuclei of fertillized mouse eggs for generating transgenic mice harbouring the introduced genes, respectively. However, we did not observed that the two genes could be expressed in transgenic mice. These results suggest that the in vivo expression of human coagulation factor IX cDNA be controlled by some cis regulatory element (s).