Lawson Laboratory



Another example of endothelial differentiation is the establishment of artery and vein identity. Arteries and veins are known to have functional differences - arteries typically carry blood flow away from the heart, while veins return it to the heart - and there are obvious anatomical differences, such as the thickness of surrounding smooth muscle and matrix layers (see figure at right). Interestingly, a number of studies indicate that the expression of
artery and vein-specific genes begins before circulation in both fish and mouse embryos. Thus, there are genetic signals that govern artery and vein identity.



Endothelial differentiation: arteries and veins