3520bp fragment corresponding to -3830 to -897 (enhancer 1), a 5bp spacer (BamHI site), plus -576 to +10 (enhancer 2) relative to the transcription start site of the eya-RB isoform are fused upstream of a minimal Hsp70 promoter followed by a cDNA encoding the eya-RB isoform (plus 3'UTR).