Figure 4. FLT1 knock-down results in impaired tube formation.
(A) Representative tube formation images with diI-stained fetoplacental ECs demonstrated impaired tube formation as early as two hours after knock-down of FLT1 that was sustained through 12 hours. Both number of branch points (B) and total tube length (C) were significantly decreased after FLT1 ablation (p<0.001 for both) with no effect of KDR knock-down on tube formation.