Figure 5.

JNK is required for the expression of Pax2, Sonic Hedgehog (Shh), and bone morphogenic protein-4 (BMP4) in the developing kidney. Hematoxylin- and eosin-stained E18.5 embryonic kidneys indicate that mutant kidneys contain enlarged tubules (low magnification; upper left panels) and have deformed renal epithelium and nephrons (high magnification; middle left panels). A high level of Pax2 protein (brown) and Shh mRNA (brown) was detected in renal epithelial cells in control E18.5 kidneys, but not in mutant kidneys. BMP4 mRNA (red) was also detected in control kidneys, counterstained with DAPI (blue), but not in mutant kidneys. Autofluorescence from erythrocytes was observed in control tissue, mutant tissue, and in control tissue hybridized with the sense probe. This autofluorescence was easily distinguished from the specific BMP4 staining observed in control tissues, but not in mutant kidneys or control kidneys stained with the sense probe.