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Fig. 1. Neural crest marker induction after recombining ectoderm to mesoderm. (A) The DMZ (blue) or the DLMZ (yellow) are dissected at stage 10-10.5 as depicted. (B) Each type of mesoderm explant is recombined to the animal cap ectoderm (AC, red) of stage 8-9 embryos, to form the DLMZ-AC and DMZ-AC recombinants, respectively. (C) RT-PCR analysis of gene expression in the stage 18 recombinants shows that the DLMZ-AC recombinants express a whole range of neural crest markers at stage 18 (Slug, FoxD3, Sox9, Zic5, Snail and Twist, lane 5), whereas the DMZ-AC recombinants express only a subset of them (lane 7). Lanes 1, 2: controls (see Materials and Methods). Lanes 3, 4, 6: isolated AC, DLMZ and DMZ, respectively. (D) In situ hybridization for the four most specific neural crest markers studied (see text) on normal embryos around stage 18 seen in dorsal view, anterior is towards the bottom. Note that Slug and FoxD3 are restricted to the neural crest, whereas Zic5 and Sox9 are also expressed in other areas. |
