Fig. 2

Fig. 2 Sema3fa is required to refine and limit retinal vessel branching in the larval eye. Live imaging of vessels (white) in Tg(kdrl:mCherry) WT (A,C,E,E’) and sema3fa^ca304 heterozygous (G,G’), and homozygous (B,D,F,F’) eyes during retinal intraocular vascular development acquired by confocal microscopy. (A, B) In lateral views of WT (A) and sema3fa^ca304 homozygous embryos, the hyaloid artery (endothelial cells labeled by mCherry) contacts the lens (asterisk) of the retina by 24 hpf (N = 1 WT n = 3; sema3fa^ca304 n = 4). (C, D) Ventral views of WT (C: N = 1, n = 4) and sema3fa^ca304 (D: N = 1, n = 4) eyes reveal that the hyaloid artery (arrowhead) forms a vascular plexus network around the lens by 72 hpf. Also evident is the nasal ciliary artery (arrows). (E–G) The WT intraocular hyaloid vessel (E’ is a magnified view of the boxed area in E) undergoes remodeling between 4-5 dpf to simplify the network (Hartsock et al., 2014). At 4 dpf, the numbers of vessel crossovers (arrows) are increased in sema3fa heterozygous (G,G’: N = 1, n = 2/2) and homozygous (F,F’: N = 4, n = 12/12) mutant embryos as compared to WT siblings (E, E’: N = 4, n = 10/11 show refinement). Scale bar: 100 µm; 50 µm for E’–G’.