Depletion of RNF213 causes abnormal vessel sprouting in zebrafish.

Tg(fli-EGFP)y1 embryos at 72 h post-fertilization. (A) Brightfield image of whole embryos (left) and confocal images of tail vessels (right) of embryos injected with a control (scrambled) or RNF213 morpholino (MO). Lateral views, dorsal uppermost, anterior to the left. In RNF213 morphants, abnormal intersegmental vessel sprouting was observed (white arrowheads). Trunk vessels, including the dorsal aorta (red arrowheads), posterior cardinal vein (blue arrowheads) and dorsal longitudinal anastomotic vessels (yellow arrowheads) developed almost normally. (B) Confocal images of intracranial vessels. (Left) Lateral views 20 degrees toward the top; dorsal uppermost, anterior to the left. (Right) Dorsal views, head to the left. The trunk artery, including the basilar artery (red arrows), lateral dorsal aorta (blue arrows), mesencephalic artery (yellow arrows) and dorsal longitudinal vein (white arrowheads) developed almost normally in controls and RNF213 morphants. RNF213 morphants showed abnormal sprouting vessels (yellow arrowheads) and irregular vessel diameter (white arrowheads). (C) Cross-sectional view at the middle of the lens level. In a control morphant, the three branches of the nasal ciliary artery (red arrowheads) drain into the inner optic circle (IOC; blue arrowheads). In two different RNF213 morphants, multiple aberrant vessels drain into the IOC (red arrowheads), and occasionally part of the IOC was missing (yellow arrowhead).

RNF213 morphants show multiple sprouting vessels from IOC. Bar graphs showing the number of sprouting vessels from IOC of Tg(fli-EGFP)y1 embryos 72 h post-fertilization. Each group was injected with 2.5 ng morpholinos (MO1, MO2) per embryo indicated in each lane. n = 20 per group. Values are means ± SD. *p<0.01 versus control scramble morphants. #p<0.01 versus RNF213-β-morphants. Neither group of controls nor RNF213-β showed any extra sprouting vessels.