Conditional targeting in the kidney.

Conditional gene targeting utilising the Cre/loxP system, which allows spatial and temporal control of gene expression, has been increasingly used to study gene function in vivo. The ability to limit gene disruption to a particular cell type and/or to control the timing of gene targeting overcomes some of the limitations associated with conventional targeting and total knockout of a gene, namely, potential embryonic lethality and complicated phenotype affecting multiple tissues. Although the application of this approach to the kidney is relatively recent, it has already proven to enhance our ability to study the developmental, physiological, and pathological processes in the kidney: dissecting the roles of several proteins in complex homeostatic systems, uncovering novel actions of proteins, and establishing models of kidney diseases. As the number of kidney-specific Cre mouse strains increases, this strategy will allow increasingly specific and complicated biological questions in the kidney to be addressed. Copyright 2007 S. Karger AG, Basel.