Fig. 4

Slit may not be involved in the axogenesis of GCs.

Slit2 was overexpressed using the hsp70l:Slit2-GFP; pou4f3:Gal4 UAS:GAP43-GFP (B-G), or hsp70l:Slit2-GFP (H-K) lines during development of the RGC and GC axons (3/4/5 dpf). The structure of the RGC and GC axons was examined at 5 dpf. Slit2-GFP was detected after 40 min of heat shock (A, lower panel). (B-G) Heat shock-induced overexpression of Slit2-GFP at 3 dpf induced abnormal axonal projections (trespass) of the RGCs (n = 2/2, indicated by an arrowhead in G). The RGC axons were visualized by immunohistochemistry with an anti-GFP antibody. Control non-induced (B, C, D) and heat-shocked larvae (E, F, G). Low- (B, E) and high-magnification dorsal views (C, F), and lateral views (D, G) of the tectum. (H-K) Heat shock-mediated overexpression of Slit2-GFP at 3 dpf did not affect the formation of GC axons (n = 10/10, J, K). The larvae were stained with anti-Vglut1 (GC axons, magenta) and parvalbumin7 (Pvalb7, PCs, green) antibodies. Overexpression at 4 or 5 dpf also did not affect the GC axons (S4 Fig). Statistic analysis is shown in S3 Table. Scale bars: 1 mm in A; 50 μm in E (applied to B), 40 μm in F (applied to C); 40 μm in G (applied to D); 100 μm in J (applied to H); 40 μm in K (applied to I).