Movie 1

Time-lapse imaging of a Tg[fli1a:EGFP]^y1;Tg[-0.8flt1:RFP]^hu5333 embryo (all ECs labeled in green, arterial ECs labeled in red) showing ISV remodelling into a venous (left) and an arterial (right) intersegmental vessel from 26 to 55 hpf (frame interval: 15 minutes). In both cases, a lumenized connection is formed between the secondary sprout and the primary ISV. In the case of the formation of an aISV, the connection is lost again and the secondary sprouts forms lymphatic precursors at the horizontal myoseptum (Parachordal lymphangioblasts). In case of vISV remodelling, the secondary sprout connection is stabilized and the connection between primary ISV and DA regresses. Scale bars, 50μm