A fragment from upstream of the slp1 promoter (coordinates 2L:3817298..3817517 , release 6 genome), in which both of the predicted slp1 binding sites have been mutated (TTCACATGTTTTGTTCGAGCA to TTCACATGTaccaagCGAGCA and CTCTTGTGTTGGTCAAATTCA to CTCTTGgagTcGatcAATTCA), is fused upstream of a basal Hsp70 promoter that is fused upstream of EGFP.