Fig. 3. NC induction by Fgf8a requires active canonical Wnt signaling in animal explants. (A) In animal explants the induction of NC markers (Snail2 and Sox8) by the co-expression of Chordin (10 pg) and Wnt8 (25 pg; C+W), or Chordin (10 pg) and Fgf8a (5 pg; C+F), is dramatically reduced in the context of embryos injected with Wnt8MO (W8MO, 50 ng) or β-CatMO (βCMO, 50 ng). Interference with the Wnt signaling pathway did not affect (C+F) or restore (C+W) the neuralization of these explants (Sox2). Values (n=3) are presented as mean±s.e.m.; ^*P<0.05, versus C+W (upper graphs) or C+F (lower graphs) samples. U, uninjected animal explant. (B) The expression of Snail2 detected by whole-mount in situ hybridization in Chordin and Wnt8 (C+W8), or Chordin and Fgf8a (C+F8a), treated animal explants is abolished by the co-injection of Wnt8MO (W8MO; 50 ng).