Overview: Gene Knockouts

The ability to generate a mouse with a targeted mutation in a desired gene has been one of the most important advances in understanding the function of gene products. Not only can gene disruption demonstrate the function of genes, but by disrupting cell development or survival it can also demonstrate the function of specific cell types. Some knockout mice are murine models of human genetic diseases and have proven that a single gene defect is capable of causing disease. In addition, the crossing of mice that are heterozygous or homozygous for specific gene mutations provides important information on human diseases that are caused by multiple genetic defects. In genetic terms, targeted gene disruption is directly complementary to (and arguably more direct than) using mutant strains of mice with a known phenotype to map and identify the disease-causing genes.