Figure 5.2

(A–J’) Lateral spinning disc confocal images of ISV endothelial cells (ECs) in 4 days post-fertilisation (dpf) EC-EKC larvae treated with either 0.5% dimethyl sulfoxide (DMSO) (A–D’), 15 μM SL327 (E–F’), 4 μM SU5416 (G–H’), or 10 μM SU5416 (I–J’). A higher concentration of SU5416 (10 μM) is required to block the Erk activity in ablated ISV ECs 3 hours post-ablation (hpa) immediately adjacent to the wound. Images (A-B’) show non-ablated control ISV ECs. Images (C, E, G, I) were taken pre-ablation and images (D, F, H, J) were taken 3 hpa. Images (A-J) show fli1aep:EKC expression, and images (A’-J’) show the nuclear fli1aep:EKC intensity. (K,L) Lateral confocal images of 4 dpf EC-EKC uninjected control (n = 100/100) (K) and kdrl crispant (n = 98/103 larvae displayed, phenotype indicated) (L). kdrl crispants phenocopy previously published kdrl mutant/morphant vascular phenotypes. (M–T’) High Erk activity is not maintained in kdrl crispants 3 hpa. Lateral confocal images of ISV ECs in 4 dpf EC-EKC uninjected control (M–N’, Q–R’) and kdrl crispants (O–P’, S–T’). Images (M-P’) show non-ablated control ISV ECs, and images (Q-T’) show ablated ISV ECs. Images (Q) and (S) were taken pre-ablation, and images (R) and (T) were taken 3 hpa. Images (M-T) show fli1aep:EKC expression, and images (M’-T’) show the nuclear fli1aep:EKC intensity. (U–X) Erk-signalling is required for vessel regeneration. Lateral spinning disc confocal images of 24 hpa, 5 dpf, EC-EKC larvae treated with either 0.5% DMSO (U), showing a regenerated ISV, or 4 μM SU5416 (V), 15 μM SL327 (W), or 1 μM Trametinib (X), all of which blocked ISV regeneration. DA, dorsal aorta; ISV: intersegmental vessel. White dotted lines/circles show the wounded site of each larva. Scale bars: 15 μm for image (A), 100 μm for image (K), 20 μm for image (A), and 50 μm for image (U).