Vangl2 is required for polarized filopodia at late gastrulation. (A) Live embryo images of gastrulation stages and embryonic regions analyzed in this study (top). Confocal live cell images of lateral mesendodermal and mesodermal cells at 80% epiboly and the ypc/tb stage, respectively (bottom). Filopodia (arrow) and larger actin-rich protrusions (arrowhead) are labeled with Lifeact-GFP. The images are oriented in relation to the anterior-posterior and dorsal-ventral embryonic body axes. Scale bars: 5 µm. (B,C) Quantitation of filopodia and large protrusion numbers in wild-type and vangl2vu67/vu67 mutant embryos (wild type at 80% epiboly, n=7 cells, 6 embryos; wild type at ypc/tb, n=13 cells, 10 embryos; vangl2 mutant, n=10 cells, 6 embryos). (D,E) Percentage of polarized filopodia and large protrusions formed in relation to the dorsal-ventral body axis. Box plots show the interquartile dataset, the median and the data range. *P<0.05, ***P<0.001, ****P<0.0001; unpaired Student's t-test with Welch's correction.