The P{DEP} element contains UASt regulatory sequences at both ends, with each copy of UASt being oriented outwards, so that when expression is driven by a GAL4 driver, transcription is directed outwards from both ends of the element, potentially driving overexpression of any nearby genomic loci in both directions. A w^+mC marker is present in between the two UASt sequences. In addition, two FRT and two loxP sites are present, such that each UASt sequence can be excised separately in vivo. Recombination using FLP removes the UASt sequences at the 5' end of the element plus the w^+mC marker (generating the P{DEP.ΔFRT} element), while recombination using P1cre removes the UASt sequences at the 3' end of the element plus the w^+mC marker (generating the P{DEP.ΔloxP} element).