The arterial and venous differentiation of endothelial cells in the forming of the cranial vasculatures of zebrafish

斑马鱼的脑血管系统由3个成血管细胞簇组成，第1个成血管细胞簇为背外侧动脉或原始颈内动脉，第2个成血管细胞簇聚集在头内区的视神经被膜处，第3个成血管细胞簇出现在后脑腹侧壁间。动脉起源的吻侧和尾侧簇表达动脉标志物#2，而出现在后脑腹侧壁间的簇表达静脉标志物Flt4。Shh在动脉血管母细胞簇的邻近区域表达，提示其可能决定动脉内皮细胞的命运。动脉-静脉分化的时间推移成像也显示颈间动脉的分支起源于吻端的动脉血管母细胞簇，椎-基底动脉的分支起源于后脑之间的静脉血管母细胞簇。

The cranial vascular system of zebrafish was composed of three clusters of the fli1 positive angioblasts, of which the first cluster recognized as lateral dorsal artery or primitive internal carotid artery, and the second cluster assembling at the rostral-internal region to the optic capsule, and the third cluster arising among the lateral-ventral wall of hindbrain. The rostral and caudal clusters of arterial origins express the arterial maker hey 2, while the clusters arising among the lateral-ventral wall of hindbrain express the venous maker flt4. Shh was expressed in the adjacent region of arterial angioblast-clusters, which are suggested to determine arterial endothelial fate. Time-lapse movies imaging the arterial-venous differentiation also revealed that the branches of intercarotid artery are originated by arterial angioblast clusters at the rostral, and the branches of vertebral-basilar artery are derived from the venous angioblast clusters arising among the hindbrain.