Podocyte-specific Expression of Cre Recombinase in Transgenic Mice

We report a transgenic mouse line that expresses Cre recombinase exclusively in podocytes. Twenty- four transgenic founders were generated in which Cre recombinase was placed under the regulation of a 2.5-kb fragment of the human NPHS2 promoter. Previously, this fragment was shown to drive beta-galactosidase (beta-gal) expression exclusively in podocytes of transgenic mice. For analysis, founder mice were bred with ROSA26 mice, a reporter line that expresses beta-gal in cells that undergo Cre recombination. Eight of 24 founder lines were found to express beta-gal exclusively in the kidney. Histological analysis of the kidneys showed that beta-gal expression was confined to podocytes. Cre recombination occurred during the capillary loop stage in glomerular development. No evidence for Cre recombination was detected in any of 14 other tissues examined.