This transgene contains a 9.5 kb fragment of the mouse aquaporin 2 gene 5'-flanking region placed upstream of a Cre recombinase sequence (with SV40 nuclear localization signal at the amino terminus and an 11-amino acid epitope tag derived from Herpes simplex virus glycoprotein D located at the carboxy terminus). The aquaporin regulatory sequences drive Cre expression in the collecting ducts of the kidney and in sperm. (J:104785)