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Figure 4. Co(III)-Ebox impairs neural crest cell migration in Xenopus embryos independently of neural crest specification.
(A) In situ hybridization showing neural crest of embryos injected with Co(III)-Ebox or Co(III)-EboxMut during neurulation stages maintained at 14 (A, C) or 27 (B, D). (A, B) Co(III)-Ebox does not affect pre-migratory neural crest at 14 (A) or 27 (B) seen by in situ hybridization for FoxD3 (top panel) or Sox10 (bottom panel) For FoxD3 embryos maintained at 14, untreated n = 14; Co(III)-EboxMut n = 15; and Co(III)-Ebox n = 15. For embryos maintained at 27, untreated = 15; Co(III)-EboxMut n = 15; and Co(III)-Ebox n = 15. For Sox10 embryos maintained at 14, untreated n = 12; Co(III)-EboxMut n = 15; and Co(III)-Ebox n = 15. For embryos maintained at 27, untreated = 15; Co(III)-EboxMut n = 15; and Co(III)-Ebox n = 15. Krox20 is used to visualize non neural crest tissue in the hindbrain. (C) Embryos treated with Co(III)-Ebox have normal neural crest migration at 14. (D) Embryos treated with Co(III)-Ebox grown at 27 show impaired neural crest migration (red arrowheads) visualized by in situ hybridization for Twist and Krox20 (top panel) or Sox10 and Krox20 (bottom panel). For Twist embryos maintained at 14, untreated n = 14; Co(III)-EboxMut n = 14; and Co(III)-Ebox n = 14. For embryos maintained at 27, untreated n = 11; Co(III)-EboxMut n = 10; and Co(III)-Ebox n = 17. For Sox10 embryos maintained at 14, untreated n = 14; Co(III)-EboxMut n = 11; and Co(III)-Ebox n = 12. For embryos maintained at 27, untreated n = 13; Co(III)-EboxMut n = 12; and Co(III)-Ebox n = 14. (E, F) Quantification of normalized neural crest migration from Twist expression represented as means s.e.m. M = mandibular, H = hyoid, BA = anterior branchial, BP = posterior branchial. (E) T-tests determined no significant difference between embryos at 14. (F) T-tests determined that neural crest streams of embryos treated with Co(III)-Ebox are significantly different from controls [single star (*), M, P = 0.0002; H, P<0.0001; BA, P<0.0001 and BP, P<0.0001] and from embryos treated with Co(III)-EboxMut [double stars (**)] M, P = 0.0245; H, P = 0.0004, BA, P = 0.0005; and BP, P = 0.0001] at 27. |
