The introduction of two transgenes into one animal is increasingly common as transgenic
experiments become more sophisticated. In this study we examine two strategies for
creating double transgenic founders from a single microinjection. In the first approach, two
constructs, each with its own promoter element, were coinjected into the pronucleus. In the
second approach, both transgenes were cloned into one vector, separated by an internal
ribosomal entry site (IRES), and placed under control of a single promoter. Both strategies …