Insertional mutagenesis in mice

Insertional mutagenesis via the introduction of exogenous DNA into the germ line has been accomplished in many organisms. In addition to causing the mutation, the introduced DNA serves as a tag for molecular cloning of the affected locus. A number of mutations due to the insertion of either retroviral or microinjected cloned DNA have been isolated in mice. Many of these mutant loci have been cloned and are being analysed to determine the molecular basis of the mutant phenotype.