L-WNK1 expression in the adult vascular system. A, D, E, and G: Whole-mount X-gal staining. B: X-gal staining of frozen sections counterstained with eosin. In situ (C) and in toto (F, H) hybridization with the L-WNK1 mRNA probe. A–C: Transgene and L-WNK1 expression in the aorta. The staining of aorta cryosections shows expression in both endothelial (arrows) and smooth muscle cells (smc). Strong expression is also evident in small arteries (a) and veins (v) at the surface of the brain (D, E), and of the mesentery (G). Endogenous L-WNK1 expression was confirmed in the brain (F) and mesenteric vessels (H). Original magnifications: ×2.5 (A); ×250 (B); ×100 (C); ×10 (D); ×5 (E, F, G); ×10 (H).