Insights into cellular energy metabolism from transgenic mice.

Rapid progress in manipulating the mouse genome now makes it possible to express any cloned gene in virtually any cell type of the mouse. Homologous recombination in embryonic stem cells allows the specific mutation of any gene. These tools are finding widespread application to problems in cell biology and physiology. After a brief description of some of the molecular genetic techniques available for the mouse, the application of transgenic mice to problems in cellular energy metabolism is discussed. The effects of increasing glucose transport on carbohydrate metabolism in muscle and fat are presented. Experiments using a transgenic mouse expressing creatine kinase in liver to understand ATP catabolism and regulation of oxidative phosphorylation are discussed. Finally, mice either lacking or misexpressing different isoforms of creatine kinase have been useful for understanding the detailed role of this important enzyme in cellular energy metabolism.