Transgenic construct used to investigate gypsy insulator activity. Contains divergently transcribed w and lacZ reporter genes with a 330bp rho lateral stripe enhancer (NEE) and a 200bp h stripe 1 enhancer (H1) inserted between the two reporters (H1 is proximal to lacZ). A 340bp gypsy insulator (SU) has been inserted in between the NEE and H1 regulatory fragments.