A 350bp gypsy\su(Hw)BR fragment flanked by loxP sites has been inserted into the endogenous y gene, at -600bp relative to the y transcriptional start site.
In y1; yP1\loxP.gypsy\su(Hw)BR-350.-600 females have low levels of wing and body pigmentation, and wild-type levels of bristle and tarsal claw pigmentation.