FLP-mediated recombination between the two progenitor insertions has resulted in the deletion of the genomic sequence between them.

Homozygotes develop to the adult stage, although with slightly reduced viability compared to wild type. Homozygous males are fully fertile, but homozygous females are sterile, laying rare embryos that show no sign of development. Most egg chambers of homozygous females appear normal, although a weakly penetrant phenotype characterised by an abnormal number of germ cells is seen. Homozygotes of both sexes show reduced longevity compared to controls (with females showing the most marked effect).