Fig. 3.

(a) The domain of wnt11 mRNA expression in an E11.5 ureteric bud is restricted to the tips. The position of the stalk is shown with a white dotted line. (b) The boundary of DBA expression in a kidney rudiment of the same age is in a similar location to the boundary of wnt11 expression in (b). (c) By 8 days of culture, when branching morphogenesis has ceased, DBA staining extends throughout the ureteric bud/developing collecting duct epithelium. In more mature, medullary regions, it takes on a speckled appearance (d). Scale bar = 100 µm.