The Center for Alternatives to Animal Testing is an academic center affiliated with the Division of Toxicological Sciences in the Department of Environmental Health Sciences of the Johns Hopkins University Bloomberg School of Public Health.

 

Johns Hopkins School of Public Health

Proceedings for CAAT 20th Anniversary Symposium

Transgenic Animals: Humane and Alternative Considerations

Pamela Reilly Contag
Xenogen Corporation

The use of light-based reporters combined with highly sensitive detectors allows monitoring of photons transmitted through live, intact mammals. This technology, called biophotonic imaging, is used for non-invasive imaging of cells and molecules inside the bodies of living animals. The tracking and monitoring of cells and molecules in this fashion offers a unique opportunity to study both disease progression and concomitant gene expression. Mice can be produced which contain transgenes consisting of luciferase (a light-based reporter) under the transcriptional control of the promoters and enhancers that drive the expression of genes in a specific pathway of interest. Activation of these genes in the light-producing transgenic animals (LPTA) results in transcription of the luciferase reporter which is then non-invasively monitored by the detection of light produced in a living animal, thus allowing real-time assessment of gene expression. This process can be constructed to allow one to study numerous biological processes; LPTAs have novel applications for drug development in areas as diverse as toxicology, wound healing and cancer. Following gene expression spatially, over time and quantitatively allows a reduction in animal use and the refinement of experimental protocols.