Areporter gene--that is, a gene whose activity is relatively easy to detect--is commonly used to study promoter activity under a variety of investigative circumstances. recombinant dna technology is used to attach such a reporter gene to the promoter of interest, after which the recombinant molecule is inserted by transformation or transfection into the cell or host organism of choice. green fluorescent protein (gfp) from the jellyfish aequorea victoria fluoresces green when exposed to blue light. assume that you wished to study the regulatory apparatus of the lac operon and you developed a plasmid (p) that contained all the elements of the lac operon except that you replaced the lac structural genes with the gfp gene (your reporter gene). you used this plasmid to transform e. coli.