Transgenic construct used to study the Fab-7 Polycomb Group response element (PRE) from the Bithorax complex. Contains: a 3.7kb HindIII fragment carrying Fab-7 (from position +122 to +126 on the BXC map) - the Ecol\lacZUAS.l5 reporter - the w+mC marker. The Fab-7 PRE sequence is oriented such that the proximal end of the element is closest to the UAS sequences of the Ecol\lacZUAS.l5 reporter.