Transgenic construct used to study promoter competition and promoter-enhancer interactions. Encodes two divergently transcribed reporters; a w minigene expressed under the control of its own promoter and lacZ driven by a P\T promoter. The AE1 enhancer (-2574bp to -2145bp relative to the ftz transcription start site) and a 340bp gypsy insulator fragment have been inserted in between the two divergent promoters, such that the gypsy insulator is proximal to the lacZ reporter.