Adult-onset retinal vasculature phenotypes in Plexin D1 mutants. A-B: Pseudo-coloured adult retinas from (A) wild type and (B) obd adult fish to facilitate quantification of the vessel branches. A black circumferential line demarks half the distance between the optic disc and the annular peripheral vein at different retinal regions (MID- retina). C: The number of main branches radiating from the optic disc and the number of vessels crossing the mid-retina are higher in obd mutants (n = 18) than in wild type retinas (n = 24). D: The average number of branch points per vessel is significantly decreased in obd (n = 5) versus wildtype (n = 5) retinas. The number of branch points per 9 randomly chosen vessels in each retina was counted from outside in. To avoid bias, the nearest vessel was chosen every 40° of retinal circumference, starting from the most ventral poin. E: A significant reduction in the distance from the optic disc branches to the secondary branches, but not to the tertiary branches, is observed in obd vessels (n = 40) versus wildtypes (n = 22).