Rapid in vivo functional analysis of transgenes in mice using whole body imaging of luciferase expression

The use of transgenic animals in biomedical research is increasing rapidly and may be the best means of determining gene function. Generating transgen ic animals typically requires time-consuming screening processes, and gene function is assessed by an array of difficult phenotypic and biochemical as says performed ex vivo. To address the unmet need in transgenic research fo r functional assays performed with ease in living animals, we demonstrate h ere that in vivo detection of luciferase enzyme as a transcriptional report er facilitates rapid screening for both the presence and function of transg enes in intact living mice. Using this approach we identified three biolumi nescent transgenic founders where the transgene consisted of the heme oxyge nase promoter fused to the modified coding sequence of the luciferase gene. These founders were identified from 183 pups and confirmed by PCR analysis . Identification of HO-1-luc homozygotes from back-crossed F-2 littermates was then accelerated by in vivo imaging. In another transgenic mouse line, where the transgene was comprised of the bone morphogenic-4 (BMP4) promoter fused to the modified luciferase gene, we were able to identify transgenic animals and in each line we were able to visualize patterns of expression in living animals over time. The light production from these transgenic mic e indicated that the desired DNA fragment was functional and different expr ession profiles apparent at different ages and after gene induction.