Intestine sections were stained with antisera directed against laminin α chains, as indicated. The dashed lines denote the crypt-villus boundary. (A) α5 was detected in the control subepithelial BM of villi but not of crypts. (B) α5 staining was greatly reduced in villus BM (arrow) of KO/Tg mice but was detectable in both the mesenchymal structures within villi and the intestinal smooth muscle wall. (C) Low levels of α1 were detected in the control subepithelial BMs of both villi and crypts. (D) Levels of α1 were increased in KO/Tg villus BM. (E) In controls, high levels of α4 were detected in the endothelial BM of blood vessels, but not in the villus subepithelial BM (arrowhead in inset). (F) In KO/Tg, in addition to endothelial BM, α4 was deposited in the villus subepithelial BM (arrowhead in inset). (G-L) Compared to WT distal small intestine, α5 was only weakly deposited in the subepithelial BMs of WT colon (arrow in H), whereas α1 and α4 were abundant. Bars=100 μm.