Fig. 3. Proximal and distal vein junctions in wild-type (A,B,E,F,I,J) and fkd1 (C,D,G,H,K,L) cotyledons at provascular (A,C,E,G,I,K) and mature vascular (B,D,F,H,J,L) tissue stages viewed with phase contrast optics. (A-D) Distal vein junction between midvein (mv) and distal secondary veins (ds) near the apex of the cotyledon. (E-H) Distal vein junction of proximal (ps) and distal secondary veins. (I-L) Proximal vein junction between distal secondary veins and midvein. Arrows indicate the failure of distal junctions in fkd1. Scale bar: 50 µm.