The Cre loxP system and gene targeting in the kidney

DNA recombination and are being increasingly utilized to study gene functio n in vivo. These systems allow targeted gene disruption in a single cell ty pe in vivo, thereby permitting study of the physiological and pathophysiolo gical impact of a given gene product derived from a particular cell type. I n the kidney, the Cre/loxP system has been employed to achieve gene deletio n selectively within principal cells of the collecting duct. Disruption of target genes in the collecting duct, such as endothelin-1 or polycystic kid ney disease-1 (PKD1), could lead to important insights into the biological roles of these gene products. With selection of the appropriate renal cell- specific promoters, these recombination systems could be used to target gen e disruption to virtually any renal cell type. Although transgenic studies utilizing these recombination systems are promising, they are in their rela tive infancy and can be time consuming and expensive and yield unanticipate d results. It is anticipated that continued experience with these systems w ill produce an important tool for analyzing gene function in renal health a nd disease.