Transgenic construct used in an enhancer-blocking assay to study whether a fragment from the lncRNA:yar promoter region can function as an insulator. Contains two divergently transcribed markers; a y minigene with wing and body enhancers upstream of the y promoter, and a w minigene with a w enhancer upstream of the w promoter. A 150bp fragment from the lncRNA:yar promoter region (containing two of the three transcription start sites) has been inserted in between the w eye enhancer and w promoter. The lncRNA:yar fragment is flanked by loxP sites in direct orientation.