In situ hybridization for AQP isoforms in developing mouse kidneys. a Digoxigenin-labeled antisense probes detected AQP1, AQP7, and AQP11 mRNAs essentially in the cortex (proximal tubules) and faintly in the medulla, whereas AQP2, AQP3, and AQP4 mRNAs are detected in collecting ducts in developing (E17.5) and mature (AD) C57 mouse kidneys. b No signal was obtained with the antisense probes for AQP5, AQP9, AQP10, and AQP12