Reporter Enzyme Assays

Reporter genes code for proteins that have a unique enzymatic activity and are used to assess the transcriptional properties of DNA elements. The use of reporter genes in transgenic animals provides a rapid method for the detection of transgene expression, which is easily distinguishable from expression of the corresponding endogenous gene of the animal. The regulatory sequences of a chosen gene are fused to a readily assayable protein coding region, examples of which are chloramphenicol acetyl transferase (CAT), β-galactosidase, and luciferase. Sensitive assays are available for each of these proteins that facilitate detection and quantitation of transgene expression. The use of these reporter enzymes allows a more rapid and sensitive method of detection than the analysis of specific transgene transcripts within the transgenic animals. The reporter enzymes described in this chapter are CAT, β-galactosidase, and luciferase.