BIOLOGICALLY-ACTIVE SYNTHETIC PEPTIDES AS PROBES OF EMBRYONIC-DEVELOPMENT - A COMPETITIVE PEPTIDE INHIBITOR OF FIBRONECTIN FUNCTION INHIBITS GASTRULATION IN AMPHIBIAN EMBRYOS AND NEURAL CREST CELL-MIGRATION IN AVIAN EMBRYOS

A new method for analyzing embryonic events dependent on a specific peptide recognition signal is described. A short, specific amino acid sequence in fibronectin has been implicated as a recognition site in fibronectin-mediated interactions. Fibroblast adhesion to fibronectin is competitively inhibited by certain synthetic peptides, including the decapeptide Arg-Gly-Asp-Ser-Pro-Ala-Ser-Ser-Lys-Pro, which appears to contain the cell recognition sequence. This peptide inhibited both amphibian gastrulation and avain neural crest cell migration in vivo, as well as the attachment and migration of neural crest cells in vitro. These processes are major cell migratory events previously suggested to involve fibronectin. Negative control included another conserved fibronectin peptide from the collagen-binding region containing the sequence Cys-Gln-Asp-Ser-Glu-Thr-Arg-Thr-Phe-Tyr and another peptide. The feasibility of using synthetic peptides directed at recognition sites in extracellular proteins as probes of morphogenetic processes is demonstrated. The hypothesis that fibronectin is involved in gastrulation and neural crest cell migration is supported.