A set of third chromosome mutant stocks derived by insertional mutagenesis using the P-element construct P{lacW}; most lines have a lethal or semi-lethal phenotype. The P{lacW} construct carries a w+mC mini-white visible marker, Ecol\lacZ enhancer trap sequences, and bacterial sequences that allow plasmid rescue (FBrf0049800).
An insertion of P{lacW} into the 5' UTR of the dco transcription unit, after the G of the GT donor splice site of the last intron. The orientation of the insertion was not reported.