7833bp of the 5' and 1921bp of the 3' genomic sequences from Ir75a is fused upstream of a membrane-targeted fusion protein containing the Tag:SS(Akh) signal peptide, the Tag:M(hCD4) transmembrane domain, a tandem fluorescent dimer composed of EGFP and GFP and an endoplasmic reticulum export signal from the Hsap\KCNJ2 gene.