Gene targeting in the mouse.

Establishment of methods to inactivate genes by homologous recombination in embryonic stem (ES) cells has provided great advantages to the field of mouse genetics. Using this technology, a number of null mutant mice, so-called knock-out mice, have been generated. The gene-targeting technology offers a strong tool that allows us to understand the function of a particular gene of interest in the whole animal and has contributed to studies in a wide variety of biological research areas. More recently, the original knock-out technology has been further refined to develop advanced strategies to generate conditional knock-out and knock-in mice. In this chapter, an overview of gene-targeting strategies is presented and procedures to generate these genetically engineered mice are discussed.