UAS regulatory sequences drive expression of a chimeric Ubx::Afra\Ubx protein in which the first 281 amino acid residues of Ubx replace the comparable region of Afra\Ubx. The protein is tagged at the C-terminal end with Tag:HA.
Expression of Ubx::Afra\Ubx281.Scer\UAS.T:Ivir\HA1 under the control of Scer\GAL4arm.PS suppresses the formation of Keilin's organs in 25% of cases.