Fig. 4. Inhibition of PlexinA4 translation by injection of AMO against plexinA4 mRNA caused reduction in the number of branches of the peripheral axons of Rohon-Beard neurons. (A-F) The peripheral axons of Rohon-Beard neurons (black circles) of 24 hpf embryos were visualized by anti-acetylated -tubulin antibody staining (A-F), and camera lucida drawings of them were made (A'-C'). The AMO-injected embryos showed reduction in the number of the peripheral axons of Rohon-Beard neurons, as shown in the lateral view (B,B') compared with normal (A,A') and control MO-injected embryos (C,C'). But in the dorsal view (E), a similar number of main trunks of the peripheral axons (arrowheads) extended out of the spinal cord as in the normal (D) and control MO-injected (F) embryos. (AC,A'-C') Lateral view; anterior is leftwards; dorsal is towards the top. (D-F) Dorsal view; anterior is leftwards. Scale bars: in C, 10 µm for A-C; in F, 10 µm for D-F. (G-I) We subdivided the trunk region of the embryos into six longitudinal areas along the dorsoventral axis (D1-D3, V3-V1), and counted the number of branching points of the peripheral axons of Rohon-Beard neurons stained by anti-acetylated -tubulin antibody (G). In AMO-injected embryos, the number of the branching points was prominently reduced (H), especially in the D2 region (I).