Movie 1

Formation of transluminal pillars and bifurcations. Time-lapse confocal imaging of the developing vasculature in the CVP of Tg(fli1a:eGFP) zebrafish between 28-32 hpf. GFP-signal is represented in black. The vascular front rapidly expands by sprouting angiogenesis and joins to form the pole. Two arrows (red, green) indicate the appearance of two transluminal pillars. Such pillars are then integrated into the CVP and remain there for many hours or even days. They are the main site where RBC splitting occurs.