TKOED - LOX, STOCK AND BARREL

The generation of panels of mutant mice by homologous recombination ha s greatly increased the ability to assess the function of particular g ene products ill vivo, The ability to control the developmental stage, the tissue and the nature of the mutation would be an important innov ation, A recent report((1)) demonstrates that the conservative site-sp ecific recombination of bacteriophage pi, namely Cre-lox, can be used successfully in combination with homologous recombination to generate temporal- and cell-restricted mutations in vivo, This technical advanc e allows a greater flexibility in gene targeting and will have a signi ficant impact on how complex gene functions are studied in vivo.