Sequence has been inserted into the attP(Bxb1) site (target site for the Bxb1:int integrase) present in crbPXGE24w-, just downstream of the crb gene. The sequence consists of Scer\GAL80tub.PH, P1\creey.PH and a w+* marker. A single loxP site is present downstream of the w+* marker.