Fig. 6

Regulation of fgf3 and fgf8 expression by Wnt3a/Wnt8 and Cdx1a/Cdx4. (A–F) Expression of fgf3 and fgf8 in the tailbud (bud stage) was reduced in the wnt3a/wnt8 (B, E) and cdx1a/cdx4 (C, F) morphant embryos (A, D, wild-type control). Note that in the wnt3a/wnt8 morphant embryos, fgf3 expression in the forebrain was expanded posteriorly, and in the hindbrain it was shifted posteriorly. Similarly, fgf8 expression in the midbrain–hindbrain boundary (MHB) was shifted posteriorly in the wnt3a/wnt8 morphant embryos. These changes in the fgf3 and fgf8 expression were probably due to anteriorization of the neuroectoderm in the wnt3a/wnt8 morphant embryos. Lateral views with dorsal to the right. (G–L) Reduction of fgf3 and fgf8 expression in the tail region of the wnt3a/wnt8 (H, K) and cdx1a/cdx4 (I, L) morphant embryos (G, J, control). 13 hpf (8-somite stage for wild-type embryos). Posterior (tail) views with dorsal to the top. (M–R) Reduction or loss of fgf3 and fgf8 expression in the tail of wnt3a/wnt8 (N, Q) and cdx1a/cdx4 (O, R) morphant embryos (M, P, control). 17 hpf (17-somite stage for wild-type embryos). Lateral views with anterior to the left.