The P+PBac{XP5.RB3} transgene represents a hybrid element produced by FLP-mediated recombination between an insertion of a P{XP} element and an insertion of a PBac{RB} element. P+PBac{XP5.RB3} consists of terminus derived from the P-element 5' end - single FRT site - a splice acceptor site - terminus derived from the Tni\piggyBac 3' end. P+PBac{XP5.RB3} is typically generated as part of a deletion-generation strategy; when the two insertions are in trans and are in the appropriate relative orientation, FLP-mediated recombination can result in deletion of the genomic region between the two original insertions along with production of the hybrid element at the recombination point. FLP-mediated recombination between a P{XP} and a PBac{RB} insertion can result in either a P+PBac{XP5.RB3} or a P+PBac{XP3.RB5} hybrid element, depending on the relative genomic locations and orientations of the original insertions.