Figure 3

A. Strategy for eve stripe 2-kni misexpression in blastoderm stage embryos. Transgenic lines were generated that contain both the enhancer and the kni coding region (top). This construct is inactive because of an intervening transcriptional stop (AAUAAA) flanked by two FLP recombinase targets (FRT), but is activated during spermatogenesis in males that also carry a b2-tubulin-FLP transgene. The active construct contains a single FRT positioned between the enhancer and the kni coding region.

B. The stripe 2 enhancer directs an ectopic expression domain of the gap gene kni in the early embryo. The top embryo shows the wild type kni expression pattern. The bottom shows the two endogenous kni domains and the ectopic domain directed by the stripe 2 enhancer.