P{PZ} insertion at -61kb in the "bx" regulatory region of Ubx, within the large Ubx intron. Ecol\lacZ gene of P{PZ} is transcribed in same direction as Ubx.
Mild Ubx bx-type phenotype, slightly enlarged halteres. Heterozygotes with In(3LR)Ubx130 show a slightly stronger transformation with a few wing bristles on the capitellum.
P{PZ} insertion is regulated by at least two Pc-group members, esc and Pcl.