Transgenic construct used in an enhancer-blocking assay. Contains divergently transcribed w and eve-lacZ reporters. A 560bp fragment containing two tandem copies of the twi proximal element (2PE), a 0.9kb core scs fragment, a 1.2kb fragment from ftz (has been shown to have matrix attachment activity and contains a ftz distal enhancer) and a 500bp eve stripe 3 enhancer (E3) have been inserted between the two reporters.