UASt regulatory sequences drive expression of a chimeric protein consisting of Akap\Ubx sequences in which the sequence C-terminal to the Ubd-A motif has been replaced with the 24 amino acid sequence C-terminal to the Ubd-A motif from Ubx.
Expression of Ubx::Akap\UbxO-QA.Scer\UAS under the control of Scer\GAL4arm.PS in embryos results in the transformation of segment T3 into A1. The penetrance of this phenotype is 100%.