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Fig. 5 – WSTF knockdown embryos display proper neural crest induction, but fail to maintain normal neural crest in later development. A–H: Two-cell stage embryos were injected with WSTF MO unilaterally into a single blastomere and analyzed by whole mount in situ hybridization at neural groove stage (stage 15) to display expression pattern of neural crest genes SNAIL and SLUG. Both genes are expressed at the neural crest boundary. WSTF knockdown has no effect on the stage 15 expression of neural crest genes SNAIL (A) and SLUG (E) (dorsal views, anterior at top). Identically treated embryos analyzed by whole mount in situ hybridization at tailbud stage (stage 30; side views of heads, anterior at top) display perturbed expression of neural crest genes SNAIL (B and C) and SLUG (F and G) on the WSTF-knockdown side (C and G). 60-lm sections through the branchial arches of unilateral WSTF knockdown embryos (anterior at top) display diminished expression of SNAIL (D) and SLUG (H) on the injected side, particularly in the internal structures (light blue staining). Arches are labeled in B–D and F–H. Asterisks indicate the relative position of missing/fused arch number 3 on the sides derived from the WSTF MOinjected blastomeres. Dashed lines in B and F indicate the plane of sectioning of D and H, respectively. Scale bars: 1 mm (A, E), 0.5 mm (B, C, F, G) and 0.1 mm (D, H). |