Transgene used to study the properties of the Wari insulator. The construct contains elements in the following order: the y wing enhancer, an FRT cassette containing the Ubx Polycomb response element (this is inserted at -1870 relative to the y transcription start site), the y body enhancer, a loxP cassette containing a 191bp sub-fragment of the Wari insulator (this is inserted at -893 relative to the y transcription start site), the y transcription unit (including the intronic bristle enhancer), and a w[+] minigene that includes the Wari insulator normally found 3' of the w transcription unit.