Fig. 2

Genetic ablation of CNS radial glia in embryos leads to excessive sprouting and an increased number of dorsal trunk vascular ECs around the spinal cord.

(A) Experimental time course for the panels (B–F). (B–E) 154 hpf TgBAC(gfap:gal4ff);Tg(UAS:mcherry-NTR);Tg(kdrl:EGFP) (B and C) and Tg(elavl3:gal4);Tg(UAS:mcherry-NTR);Tg(kdrl:EGFP) (D and E) trunks after treatment with DMSO (B and D) or 2 mM Mtz (C and E) between 30 and 154 hpf. Genetic ablation of radial glia, but not of neurons, leads to ectopic vessel sprouting in the dorsal part of the trunk (yellow arrows, C). Scale bars, 100 µm. (F) Quantification of average number of somites that showed ectopic blood vessels (10 somites examined per animal; 25 animals examined per condition). This quantification was performed at 154 hpf; fish after radial glia ablation show a dramatic increase in the number of somites with ectopic blood vessels. (G–J) 154 hpf TgBAC(gfap:gal4ff);Tg(UAS:mcherry-NTR);Tg(kdrl:nls-EGFP) (G and H), Tg(kdrl:nls-EGFP) (I) and Tg(elavl3:gal4);Tg(UAS:mcherry-NTR);Tg(kdrl:nls-EGFP) (J) trunks after treatment with DMSO (G) or 2 mM Mtz (H–J) between 30 and 154 hpf. Radial glia-ablated fish show ectopic ECs in the dorsal part of the trunk (yellow arrows, H). Scale bar, 100 µm. (K) Quantification of nls-EGFP⁺ EC number within 5 ISVs (6 animals examined per condition). Radial glia ablation leads to an approximately 30% increase in EC number in the dorsal part of the trunk (left panel), whereas no significant differences in EC number were observed in the ventral part of the trunk (right panel). See also Figure 2—source data 1 for quantification. In all panels, values represent means ± SEM (*** indicates p<0.001 by one-way analysis of variance (ANOVA) followed by Tukey’s HSD test).