Fig. 2

Foxd3 is essential for mesodermal development and axis formation. At the one-cell stage embryos were injected with a mixture of two foxd3-specific antisense morpholino oligonucleotides (MO1 + 2, total dosage 20 ng) and analyzed at the shield stage (6 hpf) (A–H) or at 24 hpf (I–L). (A, B) Live embryos (lateral views, dorsal right) showing the shield and blastoderm structure in uninjected (A) and Foxd3 knockdown (B) embryos. In situ hybridization of uninjected (C, E, G) and FoxD3 knockdown (D, F, H) embryos showing expression of cyclops (C, D), goosecoid (E, F), and no tail (G, H) (dorsal views). Uninjected (I, K) and Foxd3 knockdown (J, L) embryos at 24 hpf. Shown are live embryos (I, J), and embryos analyzed by in situ hybridization for sonic hedgehog (shh) (K, L) expression (lateral views with anterior left). A foxd3 oligonucleotide with multiple mismatches did not produce mesodermal or axial phenotypes at a dosage (20–40 ng) equal to or greater than the perfect match oligonucleotides (data not shown). See Supplementary materials for rescue experiments (Fig. S2).