Expression pattern of Vasohibin during chick development.

Vasohibin is an angiogenesis inhibitor that is induced in endothelial cells in an autocrine manner. In this study, we cloned a 500-bp fragment of chick Vasohibin cDNA and analyzed its expression pattern by in situ hybridization during chick development. From HH-stage 3, expression of Vasohibin is observed in the area opaca and it is expressed throughout the primitive streak during later stages. At HH-stage 11, Vasohibin is expressed in head paraxial mesoderm, in the vitelline vein, dorsal neural tube, intermediate and lateral plate mesoderm, Wolffian duct, and blood islands at the caudal part of the embryo. In epithelial somites, expression is seen in the region around the somitocoel, and after somite maturation, expression is observed in the myotome, which becomes stronger with development. Expression is detected in fore and hind brain, also in the retina and lens vesicle of the developing eye. In the early limb bud, expression is initiated in the mesenchyme and becomes stronger during later stages. Expression in the limb mesoderm remains strong at the margins but decreases in the central mesenchyme. At day 7, expression is seen in interdigital grooves of the digits and digit-demarcating regions. During organogenesis, expression is seen in the anlagen of the esophagus, trachea, duodenum, lungs, liver, heart, and gut. Our analysis shows that Vasohibin is expressed in a wide range of tissues and organs suggesting that Vasohibin acts as a physiological regulator of vascular development during chick embryogenesis. (c) 2007 Wiley-Liss, Inc.