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).
The insertion site was reported to be 182bp upstream of the crb initiator methionine codon.
The orientation of the insertion was not reported.