ABSTRACT Luminescence is one of the most powerful technologies for imaging the processes and structures within a cell or organism. By using a light-emitting luciferin along with a luciferase catalyst, researchers can cause cells to emit light under the appropriate conditions. For example, tumors can be made to light up and reveal their extent and location, or pathogens can be caused to glow. Presently, however, it is only possible to insert the genes for the luciferase component of this system. Luciferin, the small molecule which emits the light, has to be industrially synthesized and then added by injection or perfusion. One of the most widely used light-emitters in reporting systems is the luciferin called coelenterazine, which is naturally produced by some marine invertebrates. The genes responsible for its production have never been identified. The goal of this research is to characterize and isolate the coelenterazine luciferin biosynthesis pathway and develop it as a powerful new reporter system for luminescent imaging of cellular processes. Successful completion of this project would enable a wide range of new approaches to cellular and molecular imaging, since it would allow modified cells to become self-luminous. This is a high-risk/high-benefit research project, but its eventual success will enable a powerful new generation of molecular reporter capabilities.