Fig. 1

GFP-VASP localizes to filipodia-like protrusions and cell-cell junctions in endothelial cells undergoing sprouting angiogenesis in zebrafish in vivo. (A) GFP-VASP localizes to puncta at tips of filopodia (arrowheads) of ISV endothelial cells. Bar equals 5 µm. (B) bases of filopodia and/or distal lamella regions at cell tips show stable, elongated accumulations of GFP-VASP (arrowhead). Bar equals 1 µm. (C) Along dorsal axis, some ISVs exhibit transient lamellipodia-like protrusions (arrowhead) with GFP-VASP at the leading edge. Bar equals 3 µm. (D) As ISVs meet at the dorsal side and connect to form the lumen, lamellipodia form nascent cell-cell junctions where VASP is enriched (arrowhead). Bar equals 3 µm. (E) In dorsal aorta and patent ISVs, GFP-VASP localizes to cell-cell junctions. Bar equals 20 µm. (F) ISV cells with high levels of GFP-VASP expression (asterisk) show numerous small filopodia and fail to properly migrate to the dorsal junction point. Elapsed time shown in minutes, bar equals 100 µm.