Reporter mice for the study of intracellular receptor activity.

During the past decade the remarkable progress in molecular genetics and the possibility to engineer cells to express genes reporting on the activity of specific promoters has produced major changes in biological research. The description and validation of reporter mice for non-invasive assessment of biological and biochemical processes in living subjects and the results obtained with the models reporting on the activity of estrogen and peroxisome proliferator receptors clearly showed that such technologies have the potential to enhance our understanding of disease and drug activity. Although reporter-gene technology is in its infancy, reporter animals already represent a valuable tool for biomedical investigation. The present chapter aims at critically illustrating the methodology to be applied when dealing with reporter systems and in vivo imaging.