Fig. 1

Fig. 1 col mutant embryos display a late axial extension phenotype. Live col mutants at 4 dpf (B) have wider notochords (n) than their wildtype siblings (A). Larger notochord diameter is observed in cross-sections of the trunk of 2 col mutants stained with antibody f59 (D) as compared to wildtype (C). col mutants also display rounded somite morphology (B) unlike chevron-shaped wildtype somites (A). In contrast, col mutants do not display prominent early CE defects. For example, ntl expression in the notochord anlage at late gastrulation of col embryos (F) is indistinguishable from wildtype embryos (E). The degree of convergence of the neural plate border at the 12-somite stage identified by foxd3 expression also appears normal in col mutants (G and H).