Transgenic construct used as a control in experiments investigating gypsy insulator activity. Contains divergently transcribed w and lacZ reporter genes with a 560bp fragment containing two tandem copies of the twi proximal element (2PE) and the 500bp eve stripe 3 enhancer (E3) inserted between the two reporters (E3 is proximal to lacZ). A 1.4kb spacer sequence from λ (λ1.4) has been inserted in between the 2PE and E3 regulatory fragments.