Selective binding of lectins to embryonic chicken vasculature

Chicken embryos are an excellent model system for studies related to vascular morphogenesis. Development in ovo allows manipulations otherwise difficult in mammals, and the use of chicken-quail chimeras offers an additional advantage to this experimental system. Furthermore, the chicken chorioallantoic membrane has been extensively used for in vivo assays of angiogenesis. Surprisingly, few markers are available for a comprehensive visualization of the vasculature. Here we report the use of lectins for identification of embryonic chicken blood vessels. Nine lectins were evaluated using intravascular perfusion and directly on sections. Our results indicate that Lens culinaris agglutinin, concanavalin A, and wheat germ agglutinin can be used effectively for visualization of vessels of early chicken embryos (E2.5-E4). At later developmental stages, Lens culinaris agglutinin is a better choice because it displays equal affinity for the endothelia of arteries, veins, and capillaries. The findings presented here expand our understanding of lectin specificity in the endothelium of avian species and provide information as to the use of these reagents to obtain comprehensive labeling of the embryonic and chorioallantoic membrane vasculature.