The P{Mae-UAS.EP^S} element contains UAS regulatory sequences and Hsp70 promoter sequence (-45 to +33) at its 3' end, oriented so that in the presence of a GAL4 driver, transcription from the Hsp70 promoter is directed outwards from this end of the element. The P{Mae-UAS.EP^S} element typically inserts at the 5' end of genes, resulting in over- or mis-expression of the endogenous gene in the presence of a GAL4 driver. A set of GAGA binding sites are inserted upstream of the UAS sequences to prevent position effects. A w^+mC marker is present at the 5' end of the element, and gypsy insulator sequences have been inserted between the marker and the UAS sequences to prevent the UAS sequences acting on the promoter of the marker.