Fig. 4. Role of S785 in directed cell migration. F9 outgrowth and GD25 cell migration was examined on laminin coated substrates. Parietal endoderm outgrowth assays were used to measure the role of S785 in F9 cell migration (A). All cell lines produce extensive outgrowth when plated on laminin. F9-S785S and F9-S785M produce moderate to extensive outgrowth in the presence of the antibody CD29 HA2/5. Untransfected and F9-S785D cell outgrowth is inhibited. (B) Extent of outgrowth, for cells treated (AB) or untreated (CTL) with the ß1 function-blocking antibody CD29 HA2/5, was quantified by measuring the distance from the edge of the embryoid body to the outermost edge of outgrowth at ten points for ten embryoid bodies. Error bars represent ±s.e. of triplicate experiments. (C) Boyden chamber assays were used to measure migration of GD25 cell lines. Error bars represent ±s.e. of quadruplicate experiments. An intermediate level of migration is seen with the GD25-S785M2 and significantly reduced migration with GD25-S785D2.