FIBRONECTIN PEPTIDE DRVPHSRNSIT AND FIBRONECTIN RECEPTOR PEPTIDE DLYYLMDL ARREST GASTRULATION OF RANA-PIPIENS

Gastrulation is characterized by dramatic cell migration which is thou ght to require the interaction of cell adhesion molecules with extrace llular molecules. We have tested two novel peptides, a fibronectin pep tide and a fibronectin receptor peptide, for their effects on gastrula tion of the leopard frog Rana pipiens. The fibronectin peptide DRVPHSR NSIT corresponds to residues 1373-1383 of the cell-binding domain of f ibronectin; the receptor peptide DLYYLMDL corresponds to residues 124- 131 of beta 1 subunit of a variety of integrins including alpha 5 beta 1. Either of these peptides significantly inhibited gastrulation afte r being microinjected into mid-blastulae. These results indicate that these sequences may correspond to the ligand/receptor interaction site s of fibronectin and its receptor(s).