UAS regulatory sequences drive expression of a mutated form of sog which lacks cysteine repeat domain 4 (CR4) and has a mutation of a conserved tryptophan residue to alanine in each of cysteine repeat domains 1, 2 and 3.
Expression of sogΔCR4.A123.Scer\UAS under the control of Scer\GAL4Bx-MS1096 does not produce a mutant wing phenotype.