Transgenic construct used to study the effect of transcriptional read-through on Polycomb response element (PRE) activity. Order of sequences (from P3' to P5') is: UAS sequences, GFP coding sequence, a 660bp minimal bxdPRE (in reverse orientation) flanked by FRT sites, a Hsp26-lacZ reporter and a mini-w reporter that includes the eye enhancer. The UAS sequences are oriented 'inwards' so that GAL4-driven transcription is directed through the GFP and bxdPRE sequences.