Effects of fibronectin and its peptide fragment on preimplantation mouse embryo

To investigate the involvement of fibronectin in the early development of mouse embryo, embryos at the two-cell stage were cultured in serum-free Ham F-10 medium with or without fibronectin-related substances. When antibody raised against fibronectin was added at concentrations of 0, 10(-3), 10(-2), and 2 X 10(-2) (vol:vol), the percentages of cells in the blastocyst stage at 72 hours were 88.5%, 67.2%, 48.1%, and 0%, respectively. No inhibitory effects were observed with nonspecific antibody. A low concentration of exogenous fibronectin (up to 0.2 mumol/L) slightly enhanced mouse embryo development after 48 hours. However, a higher concentration (greater than 0.4 mumol/L) of fibronectin inhibited mouse embryo development. A competitive blocker of cell membrane fibronectin receptors, oligopeptide (Gly-Arg-Gly-Asp-Ser), inhibited mouse embryo development in a dose-dependent manner. Meanwhile, control peptide (Gly-Arg-Gly-Glu-Ser-Pro), which does not contain the crucial cell binding sequence, did not show any inhibitory effects. These findings suggest the necessity of endogenous fibronectin-blastomere interaction in early mouse embryo development.