phiC31:int-mediated recombination has been used to replace the RMCE cassette containing the complete 1360 element which is present in the P{w+(FRT.attP.1360)} docking site with sequence (from a donor construct) encoding a partial 1360 element (lacks the left half of the element, and contains three 80bp deletion spanning each of the putative transcription start sites). The partial 1360 sequence present in the recombinant P{w+(FRT.1360ΔTSS)(loxP.y+)} element is flanked by FRT sites. A loxP cassette containing a y[+] marker (originating from the donor construct) and a w+mW.hs marker (originating from the docking site) are also present.