In another approach, the pluripotent stem cells derived from embryonic blastocysts are elctroporated by foreign DNA containing the gene of interest. The microinjected stem cells are reintroduced into the blastocysts which are then transferred into the uterus of a pseudopregnant recipient animal (Figure 9.2).

Figure 9.2 Alternate approach:

Both the methods are successful only after multiple generations of breeding and selection of the most stable transgenic line. Plasmid DNA containing gene of interest can be coupled with a tissue specific promoter to make it as an inducible system. Cytomegalovirus promoter is used widely as a promoter for the inducible system. Alternatively the recombination of gene of interest can also be achieved by Cre-lox pathway.