Pax8-CreERT2 mediated β-galactosidase expression.

(A) Enzymatic X-gal staining of cryosections of kidneys (top panels) derived from 10 week old Pax8-CreERT2/Rosa26R mice either induced with tamoxifen (a, renal parenchyma; b, collecting ducts) or uninduced (c). Tamoxifen administration did not induce β-galactosidase expression in any of the other major organs examined (representative tissues presented in bottom panels). (B) β-galactosidase positivity was exclusively found in the tubular epithelium of the kidney of tamoxifen treated mice, with no staining observed in glomeruli or bloods vessels (a, framed area is shown enlarged in b). Kidneys from vehicle treated mice were negative (c). Co-localisation studies revealed X-gal expression within tubules of all renal tubular compartment (proximal tubules—AQP1, distal tubules–THP and collecting ducts–AQP2). Scale bars, 100μm.