wg-induced regeneration and transdetermination. (A) Leg-to-wing transdetermination was induced in each heterozygous PZ insertion line by ubiquitously expressing wg in mid-second instar larvae (60 h after egg deposition, AED) using the FLP/FRT system(for details see Section 5). (B) Using this protocol, wg overexpression alone (Actin5C>wg, referred to as the wg-induced transdetermination control) induces ectopic Vg expression (white arrows) in leg discs with a moderate frequency of 32% (n = 60 discs).White scale bar, 50 μm. (C and D) Leg cuticle fromActin5C>wg pharate adults (differentiated but not enclosed animals) contain wing tissue with a frequency of 25% (n = 69 legs). (C) Black circle within the leg cuticle highlights ventral wing hinge structures including the yellow club (YC) and pleural wing process (PWP). The proximal leg segments, coxa and femur, are labeled. (D) Leg cuticle with transdetermined wing structures (YC and PWP) at a higher magnification than in (C). Black scale bars, 100 μm.