Transgenic construct used to study the function of the trithorax complex in the context of a Polycomb response element (PRE). Order of sequences (from P3' to P5') is: a 1.6kb bxd PRE fragment, four copies of the Ecol\lexA protein binding site, four copies of the GAL4 protein binding site, a lacZ reporter (comprising the Ubx embryonic BX enhancer, the Ubx 2212H1 imaginal disc enhancer, the Ubx promoter and lacZ coding sequence), a w+mC marker.
Construct: 1.6kb StyI-EcoRI fragment containing the Ubx PRE (Polycomb group response element).