Figure 2.

Figure 2.

Direction of blood flow and distribution of arteries and veins in the developing spinal cord vasculature. (a) Schematic of vertebral column in zebrafish, with a magnified view of abdominal vertebrae on the right. (b) Schematic of the SC plane acquired during live imaging. (c) Projection of 500 time-frames (300 ms interval) acquired in live 3–4 wpf fish with labelled ECs (Tg(kdrl:HRAS-mCherry)) and thrombocytes (Tg(-6.0itga2b:EGFP)) (n = 7). The intervertebral spaces are labelled with orange arrows, arteries in red and veins in blue. c′,c″. Projections of the region shown in (c) with flowing cells colour-coded by time (electronic supplementary material, movie S1). (d) Projection of 1500 time-frames (17 ms interval) acquired in live 3–4 wpf casper fish injected intracardially with 10 KDa dextran conjugated with Alexa-647 (A647) (n = 8). Vertebrae, arteries and veins were identified as in (c) (electronic supplementary material, movie S3). (e) Rostral-caudal distribution of arteries and veins in abdominal vertebrae, with position normalized to vertebra length, in the two blood flow models: Tg(-6.0itga2b:EGFP) and dextran-A647. (f) Combination of all vertebrae and all samples shown in (f) in a single plot. (g) Schematic of the organization of arteries and veins in the developing SC vasculature. (CC, central canal). (h) Frequency of vertebrae that present each combination of number of arteries and veins. (i) Distance in µm of each artery/vein from the closest rostral artery/vein (each dot represents a vessel).