Fig. 2. Localization of Bves during coronary vessel development. Bves-positive mesenchymal cells accumulate in the tunica media of developing arteries. Anti-smooth muscle actin (green) shows differentiated smooth muscle cells. (A) Delaminated mesenchyme from the epicardium accumulates around a developing vessel (v). (B) Bves-positive cells differentiated into vascular smooth muscle (Reese et al., 1999) and additional Bves-positive cells continue to be recruited to the vessel shown in the 3D composed image. (C-E; C, Bves; D, merge; E, smooth muscle actin) Bves has two staining patterns in cells of the developing artery. Outer, Bves-positive cells have the characteristic punctate staining of mesenchymal cells, while Bves is broadly distributed in differentiated smooth muscle cells of the inner lamellae. Arrows distinguish the boundary between the two staining patterns. (F) Later, all smooth muscle cells of the tunica media of coronary vessels have a peripheral staining pattern.