Fig. P1.

Transposons for genome engineering. Transposons are DNA segments bounded by special sequences at their termini (black triangles). At these terminal sites, the transposon-encoded transposase enzyme binds the transposon, makes double-strand breaks in the DNA to cut the transposon away from the donor site, and then inserts it into a target DNA. Two plasmid systems, which can be introduced into mammalian cells by transfection, are often used for genome engineering to allow separate manipulation of the transposon and transposase. Transposons can serve as vectors to introduce genetic material for many purposes into a target genome. Here, your favorite gene (YFG) is the material being introduced. Two highly active transposons with target site selectivities, TcBuster and SPIN, are described here, which expand the toolkit available for genome engineering.