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Fig. 5
vclb deficiency causes disorganization of coronary vessels. The Tg(fli1a:EGFP) transgenic line (endothelial cells labeled by EGFP) is used to trace coronary vessel development. The Tg(tcf21:dsRed) transgenic line is used to label epicardial cells. (A-H) In wild-type hearts, coronary vessels first appear on the dorsal surface of the ventricle and are close to the atrium-ventricle connection at ~28 dpf. Coronary vessels then spread, extend, and wrap the entire ventricle wall from 35 to 55 dpf. Dorsal views (A-D) and ventral views (E-H) are shown. (I-P) In the v12 mutant, coronary vessels appear at the same place as in wild-type siblings, but more vessels are detected at the initial stages. Wild-type coronary vessels are well connected to each other, but the overproliferated mutant vessels remain isolated and disorganized. Dorsal views (I-L) and ventral views (M-P) are shown. (Q-R') In the v12 mutant, coronary vessels are surrounded by epicardial-derived cells (R,R') rather than by cardiac muscles as in the wild-type sibling (Q,Q') at 55 dpf. MF20 stains cardiac muscles. Arrows indicate vessels that are (Q,Q') or are not (R,R') in contact with cardiac muscle. (S-V'') At 40 dpf, Tg(fli1:EGFP)-labeled endothelial tubes in wild-type ventricles are well aligned with Tg(tcf21:dsRed)-labeled epicardial-derived perivascular cells (S,S',U-U''). By contrast, most of the endothelial tubes in v12 mutants are not well aligned with perivascular cells (T,T',V-V''). Note the overproliferated endothelial and perivascular cells in the mutant. Results are shown in whole-mount view (S-T') and cryosection (U-V''). Scale bars: 100 μm in A-P; 10 μm in Q-R′; 20 μm in S-V″.