Fig. 4

Fig. 4 Analysis of MHB markers in Df^w5 embryos. (A, B, E, F, I, J, M, N, Q, R) 12-somite stage embryos. (C, D, O, P) 27 hpf. (G, H, K, L, S, T) 24 hpf. Embryo genotypes are indicated above each column, and probes assayed are indicated to the right of each row. (U, V) 27-hpf Df^w5 embryos; probes are indicated. (All panels) Lateral views of heads, anterior to the left. Reduction in pax2.1 in Df^w5 is first noticeable as a weaker staining at the MHB at the 12-somite stage (B, arrow). (A, B) Insets: Posterior views of MHB pax2.1 expression. Arrow in (B) inset indicates dorsal pax2.1 expression. At 27 hpf, ventral expression of pax2.1 is absent (arrowheads in C, D) leaving only a spot of pax2.1 expression between the cerebellum (arrows in C, D, G, H, K, L) and optic tectum. The reduction in en2 is more clearly seen as a loss of ventral expression at 12 somites (compare arrows in E, F), but at 24 hpf, en2 expression mirrors that of pax2.1 (compare G, H with C, D). The reduction of her5 in 12-somite-stage Df^w5 embryos is visible as a reduction in the entire expression domain (arrows in J indicate thinner band of her5 expression). At 24 hpf, loss of ventral her5 in Df^w5 embryos is evident (L, arrowhead). In contrast, fgf8 expression frequently appears normal in Df^w5 embryos at 12 somites (M, N) and 24 hpf (O, P; asterisk indicated MHB expression domain). Similarly, en3 expression in 12-somite Df^w5 embryos is indistinguishable from wild type (Q, R), but an overall reduction in expression is clear at 24 hpf (S, T; compare width of band between arrows). (U) Expression of wnt3a is indistinguishable between wild type and Df^w5. (V) Expression of wnt8b is indistinguishable between wild type and Df^w5.