The influence of cell-matrix interactions on the development of quail chorioallantoic vascular system

The extracellular matrix-component fibronectin (FN) was detected in close localisation to the vascular system (VS) of the quail chorioallantoic membrane (CAM). We have examined the role of cell-fibronectin interactions within the developing CAM. In two series of experiments the CAM was directly exposed to (1) an antibody against the cell-binding fragment of FN, and to (2) RGD-containing synthetic peptides which are recognized by the FN receptor. For controls an antibody against tubulin and a SHLVE-pentapeptide that does not interfere with the FN-receptor were applied. In the presence of anti-FN antibodies and RGD-sequences the CAM could not establish a normal vascular system. We observed hypo- and partially avascular regions; the resulting vascular pattern was atypically lacunar. None of the control substances affected the regular development of the chorioallantoic vascular system. These results demonstrate the essential role of FN in CAM angiogenesis.