Fig. 7

Disruption of hindbrain development in val^- embryos does not further delay expression of dlx-3. Shown are expression patterns of both dlx-3 and krox-20 at (A–D) 11 h, (E–H) 12 h, and (I–L) 14 h. Although embryos lacking val function cannot be morphologically distinguished at the early developmental stages examined here, val^- embryos were identified unambiguously by virtue of their low levels of krox-20 expression in rhombomere 5. Expression of dlx-3 is normal in val^- (A, E, I) and ntl^-;val^- embryos (B, F, J). Upregulation of dlx-3 in the otic regions (arrows) in oep^-;val^- (C, G, K) and ntl^-;oep^-;val^- embryos (D, H, L) is delayed to roughly the same extent as in oep^- and ntl^-;oep^- embryos with normal val function (see Fig. 3).