Gene Targeting in ES Cells

In the ten years since the first gene-targeting experiments were performed in murine embryonic stem (ES) cells (1 –5 ) and the mutations successfully transmitted through the mouse germline (6 –11 ), the application of a variety of gene-targeting methodologies has generated a remarkable number of novel and informative mutant mouse strains that have been invaluable not only for the study of gene function in vivo, but also serving as model systems for human disease.