A fragment from downstream of the slp2 gene (coordinates 2L:3842770..3843619 , release 6 genome), in which predicted ey binding site 1 has been mutated (TTGTGCCCTGTGTGTGTGAAA to aTGTGgCtTGTGTGTGTGAAA) and predicted ey binding sites 2 and 3 have been deleted (deletion of TGATTCCAATTGACTGATTTC and ATGTGAGCCACTTGTGTGGCA), is fused upstream of a basal Hsp70 promoter that is fused upstream of EGFP.