Wnt11 is sufficient for EAD ectoderm convergent extension. (A) Sufficiency of Wnt11 for midline CE was tested with an animal cap transplant technique. Experimental schematic of bilateral transplants with mApple, animal cap overexpressing Wnt11 or a control, secreted protein (inactive MMP11). (B-E) Overlay of brightfield images with mApple fluorescence indicating location of donor transplant in late tailbud recipients (stage 28). Scale bar: 200μm. (F-I’) Coronal sections of animal cap transplants with mmp11 or wnt11 overexpressing donor tissue assayed in 3 experiments with β-catenin immunolabeling ((F, F’) control MO+mmp11 n=15; (G, G’) control MO+wnt11 n=14; (H, H’) sox9 MO+mmp11 n=18; (I, I’) sox9 MO+wnt11 n=22). Midline region with bright β-catenin labeling is EAD ectoderm. Bracket: region of 10x image (F-I) enlarged in 25x view (F’-I’). (J) Quantification of height over width of EAD (see Methods). P values: unpaired, two-tailed T test. Error bar: standard deviation. Unless otherwise specified, Scale bar (10x): 170μm. Scale bar (25x): 68μm.