Imprecise excision of the P{EP}pcmG1726 insertion, which has resulted in a partial excision of the inserted P{EP} element together with a duplication of genomic sequence. The mutated locus comprises: 24bp of pcm 5'UTR, approximately 2kb of sequence derived from P{EP}, approximately 200bp of sequence from upstream of pcm, and a complete copy of the pcm gene in which there have been two nucleotides changes (a T to C change 54bp upstream of the transcription start, and a C to T change at +17 within the 5'UTR).
Homozygotes have an extended third larval instar stage compared to controls and die as pupae.
Homozygous larvae have small wing imaginal discs due to increased apoptosis.