Fig. 5

Fig. 5 In situ hybridization analysis of axial markers in blf morphants, injected with 2 ng of MO2. Anterior is to the left in all panels. (A, B) Notochord marked by no tail (ntl) expression at the 10-somite stage. Note the shortened, thickened, and undulating notochord in blf morphants (B), compared with control uninjected embryos (A). (C, D) Sonic hedgehog (shh) marks the notochord (n) and the floorplate (fp) at the 22-somite stage. Note the undulating notochord and floorplate in blf morphants (D), compared with control uninjected embryos (C). (E, F) myod expression marks paraxial somitic mesoderm at the 10-somite stage. Note wider and compressed somites as well as undulations in adaxial stripes of myod-expressing cells in blf morphants (F), compared with control uninjected embryos (E). (G, H) Expression of spondin1b (spon1b) marks the floorplate at the 22-somite stage. Note severe undulations (arrows) and delaminating cells (arrowhead) in blf morphants (H), compared to uninjected control embryos (G). Inset, high-magnification dorsal view of the floorplate. Note the wider and disorganized floorplate in the inset (H). A cluster of spon1b-expressing cells failed to converge to the midline (arrowhead, inset in H). (I, J) Expression of the forkhead family transcription factor foxA1 (fkd7) marks the floorplate (fp), the hypochord (hc), and endoderm at 24 hpf. Note undulations of the floorplate and the hypochord in blf morphants (J), compared with uninjected controls (I).