Chuzhoi mutants exhibit reduced length to width ratio but no change in proliferation or polarity. (A) Measurements of midline axial length and width of embryos at the level of the third somite, around the time of Closure 1. (B) Comparison of length to width ratio of wild-type (blue), heterozygous (green) and chuzhoi mutant (red) embryos over 3-7 somite stage, demonstrating a reduced rate of increase in the length/width ratio in chuzhoi mutants, compared to wild-type and heterozygous littermates. This difference indicates a defect in convergent extension in chuzhoi mutants. (C, D) Immunostaining for phosphorylated histone H3 to examine cell proliferation in the neuroepithelium of E8.5 wild-type (C) and chuzhoi mutant (D) embryos. Red; phosphorylated histone H3; blue, DAPI. (E) Quantitative analysis of cell proliferation in the neuroepithelium, displayed as the percentage of cells stained for phosphorylated histone H3, revealing no significant difference in proliferation in chuzhoi mutant embryos. (F-I) Immunostaining of transverse sections through wild-type (F, H) and chuzhoi (G, I) E8.5 embryos with anti-ZO-2 (F, G) and phalloidin (H, I) revealing no substantial difference in expression in chuzhoi mutants.