Transgenic construct used to study the properties of the gypsy insulator. Order of elements: y+mDint2 marker, a 1.6kb StyI-EcoRI fragment containing the Ubx PRE (Polycomb group response element), and a w reporter in which regulatory sequences from -1084 to -1465 (containing the eye and testis enhancers) are present upstream of the w+mC transcription unit. Two copies of the su(Hw) binding region of the gypsy element (nucleotides 647-1077, coordinates according to GenBank:M12927, contains all 12 su(Hw) binding sites) are also present. One is downstream of the w transcription unit. The other is inserted in between the PRE sequence and the w eye enhancer.
Constructs P{SUPor-P.PRE#2} and P{SUPor-P.PRE#6} differ in the orientation of the fragment containing the y enhancer, y coding region and UbxPRE. In construct P{SUPor-P.PRE#6} the y gene is transcribed in the opposite orientation to the w gene present in P{SUPor-P.PRE#6}. In construct P{SUPor-P.PRE#2}, the fragment containing the y enhancer, y coding region and UbxPRE has been reversed so that the y gene is transcribed in the same orientation as the w gene.