Analysis of Rohon-Beard cells.

(A) A higher-magnification view of a 24-hpf embryo hybridized with thecbfb antisense RNA probe and immunostained with an anti–HNK-1 antibody. The white arrow indicates a Rohon-Beard cell with lower level of cbfb expression, whereas the black arrow indicates a Rohon-Beard cell with higher level of cbfb expression. (B,C) Expression of cbfb in Rohon-Beard cells of wild-type andnarrowminded embryos, respectively. Black arrows point to the location of Rohon-Beard cells. (D,E) HNK-1 staining of Rohon-Beard cells in wild-type and vampire embryos, respectively. The arrows point to the interruption of Rohon-Beard cells at the level of the end of yolk sac extension. The insets at the lower right corner of panels D and E show close-up views of the Rohon-Beard cells as large neurons with horizontal axons, which do not extend further anteriorly after the place indicated by the arrowhead in the vampiremutant embryo.