Transgenic construct used to study whether the Zaf1 protein can mediate long-range enhancer-promoter interactions in vivo. Consists of 10 UAS sites, six Zaf1 protein-binding sites, a y marker gene, six Zaf1 protein-binding sites and a w marker. One of the sets of six Zaf1 protein-binding sites is flanked by loxP sites. The UAS sites are at -893bp relative to the y transcription start site, and at a distance of almost 5kb relative to the w transcription start site.