Transgenic construct used to study a Polycomb response element (PRE) in the vg region. Generated in vivo by integration of donor plasmid sequence into the attP site present in the P{attP,y⁺,w^3'} element. As a result of the integration event, a 300bp fragment from the proximal vg PRE (normally located 300bp downstream of the vg transcription start site), with a deletion of a Pc protein-binding site, is inserted directly upstream of a reconstituted w[+] reporter.