Xenbase Image ID: 45373

Fig. 5. NC maintenance requires activation of Wnt and BMP. (A-E) Explants of the NC and underlying intermediate mesoderm were taken at stage 16, cultured until sibling embryos were at stage 23 and analysed for the expression of the NC marker Snail2. Position of beads is indicated by the blue circle. (A) Diagram of experiments shown in B-E. (B) Control explant cultured in the presence of BSA-soaked bead. (C-E) Explant cultured in the presence of beads soaked with Dkk1 (C), Noggin (D), BMP4 (E). (F-I) Explant of the NC alone were taken at stage 16 and cultured until sibling embryos were at stage 23, then analysed for expression of Snail2. (F) Diagram of experiments shown in G-I. (G) Control explant. (H) Explant from embryos previously injected with β-cateninGR were cultured with or without dexamethasone. (I) Explant cultured in the presence of BMP. For each condition, the percentage of conjugates expressing Snail2 is summarised in the graphs. Each experiment was repeated at least three times. (J,K) IM was dissected from stage 16 embryos and the expression of Wnt8 (J) and BMP4 (K) was analysed. (L-Q) Analysis of NC markers and inducers in stage 16-18 neurula embryos as indicated. (L) Double stating against Snail2 and 12-101 antigen (a muscle specific monoclonal antibody) (Kintner and Brockes, 1984). (M) Double in situ hybridisation against Snail2 and Wnt8. (N) BMP4 expression. (O-Q) Sections of equivalent embryos to those shown in L-N. n, notochord; S, somites; IM, intermediate mesoderm; NC, neural crest. (O) Snail2/12-101 staining showing that it is the IM and not the somite the tissue that underlay the NC. (P) Wnt8 is expressed in the IM. (Q) BMP4 is expressed in the ectoderm next to or within the NC. Image published in: Steventon B et al. (2009) Copyright © 2009. Image reproduced with permission of the Publisher and the copyright holder. This is an Open Access article distributed under the terms of the Creative Commons Attribution License. Gene Synonyms Species Stage(s) Tissue wnt8a.L wnt-8, wnt8, Xwnt-8, Xwnt8 X. laevis Sometime during NF stage 16 to NF stage 18 intermediate mesoderm snai2.L slug, snai2-a, snai2-b, Snail2, xSlu, xslug, XSnail2 X. laevis Sometime during NF stage 16 to NF stage 18 neural crest mesoderm neural plate somite neuroectoderm bmp4.L bmp2b, bmp2b1, bmp-4, bmp4-a, bmp4-b, DVR-4, ofc11, XBMP-4, xbmp4, zyme X. laevis Sometime during NF stage 16 to NF stage 18 ectoderm neural crest neural plate neuroectoderm anterior neural fold Image source: Published Larger Image Printer Friendly View

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