Scer\FRT-mediated recombination between the two progenitor insertions has resulted in the deletion of the genomic sequence between them.
Df(3R)J18/Df(3R)J16 mutant flies are lethal at the third instar larval/pupal stages.
Homozygous Df(3R)J18 mutants are lethal during the third instar larval/pupal stages.