Localization of LL5α in mouse tissues. (A) Schematic diagram of a lobule from a mammary gland based on an example from a previous paper (Debnath et al., 2003). The mammary epithelium possesses a polarized architecture surrounding a hollow lumen, which is surrounded by an inner layer of luminal epithelial cells and an outer layer of myoepithelial and basal epithelial cells. (B) Immunofluorescence staining of mammary tissues with the indicated antibodies. LL5α is localized to the basal cortex of the outer epithelium attached to laminin-containing BMs (b) but not to the β-catenin–positive lateral membranes (a). (C) Colocalization analysis similar to Fig. 1 E. Entire square areas, including the gland structure, were analyzed. (D and E) Immunofluorescence staining of the small intestine. LL5α is localized to the basal cell cortex attached to the laminin BMs. The tip region of a villus is magnified in E. (F) Colocalization analysis similar to Fig. 1 E. Boxed areas a (villus) and b (crypt) in D were analyzed. LL5β showed a similar distribution pattern to LL5α both in mammary glands and intestines (not depicted). Bars: (B) 20 µm; (D) 100 µm; (E) 50 µm.