Fig. 4. Morphology of mammary glands from wild-type and Vdr knockout mice. Formalin fixed inguinal mammary glands from 6-week-old virgin wild-type (A) and Vdr knockout (B) mice were sectioned and stained with Hematoxylin and Eosin. Longitudinal sections through two terminal end buds are shown in each panel. The terminal end bud in B is undergoing bifurcation, which will result in a branch point. Scale bar: 100 µm.