Quantifying the Activity of cis-Regulatory Elements in the Mouse Retina by Explant Electroporation

Transcription factors control gene expression by binding to noncoding regions of DNA known as �cis -regulatory elements (CREs; i.e., enhancer/promoters). Traditionally, cis -regulatory analysis has been carried out via mouse transgenesis which is time-consuming and nonquantitative. Electroporation of DNA reporter constructs into living mouse tissue is a rapid and effective alternative to transgenesis which permits quantitative assessment of cis -regulatory activity. Here, we present a simple technique for quantifying the activity of photoreceptor-specific CREs in living explanted mouse retinas.