PBac{IS.IVS-GAL80-WPRE.w-} represents a transgenic construct generated in vivo using the InSITE system; an enhancer trap cassette that contains a minimal P\T promoter followed by sequence encoding the GAL80 suppressor (IVS-GAL80-WPRE cassette with codon optimized GAL80), derived from the P{ID.IVS-GAL80-WPRE} donor element, has been inserted into a PBac{IT.GAL4.w-} target element, by first using FLP recombinase to release the donor cassette and then using phiC31:int integrase to insert this cassette into the attP site in the target element. Finally, the swap has been completed by using P1cre recombinase to remove the original GAL4 enhancer trap cassette present in the original PBac{IT.GAL4.w-} target element (this also removes a w^+mC marker inserted during the second step, thus the final PBac{IS.IVS-GAL80-WPRE.w-} construct is not marked with w[+]). A single loxP site is present downstream of the GAL80 sequence.