PSM|NT interfaces of cdh2-/- (A, B, C) and MZ itgα5-/- (D, E, F) mutants at the 12–14 somite stage. F-actin (A, D), Fibronectin (B, E), and processed images of small and large Fibronectin matrix elements (C, F) are shown. All images are dorsal views. A = anterior, P = posterior, M = medial, L = lateral. Scale bars = 10 μm. (G) Quantification of Fibronectin density within the anterior 150 μm of the PSM|NT interface in wild type, cdh2-/- and MZ itgα5-/-. cdh2-/- vs WT, p=9.4e-3; MZ itgα5-/- vs WT, p=0.012. Quantification of the medial-lateral distributions of the F-actin (H, J) and small and large Fibronectin matrix elements (I, K) at the PSM|NT interface in cdh2-/- (H, I) and MZ itgα5-/- (J, K). Sample sizes: G, I, K, n = 10 PSMs from six embryos for WT, n = 10 PSM from five embryos for cdh2-/-, n = 5 PSM from five embryos for MZ itgα5-/-. Sample sizes: H, n = 7 PSM from four embryos; J, n = 5 PSM from five embryos.