Antibodies to β1‐integrins cause alterations of aortic vasculogenesis, in vivo

Abstract

Vasculogenesis is the de novo formation of blood vessels from mesoderm. This process occurs very early in development and provides a convenient system for studying morphogenesis in higher vertebrates. The cell‐extracellular matrix (ECM) interactions that occur during dorsal aortic vasculogenesis were examined using the monoclonal antibody, CSAT, a reagent known to neutralize the ligand‐binding activity of avian β₁‐integrins. We injected CSAT into quail embryos during a period of active vasculogenesis (4–10 somites). The CSAT antibodies, but not controls, had a marked and reproducible effect on aortic vessel formation. Vasculogenesis appeared to be arrested at the stage when slender cord‐like assemblies of angioblasts rearrange to form tubules. Indeed, aortic primordia near the site of CSAT injection did not form patent vessels.