Fig. 5

Increased intraluminal pillar number in rasa1−/− indicates incomplete intussusceptive angiogenesis. (A-D′) Confocal images of the caudal venous plexus of wildtype (A,C) and rasa1−/− mutants (B,D) on Tg(kdrl:EGFP) (black) at 30 hpf and 48 hpf. (A′,B′,C′,D′) Stacks of two to four slices illustrate regions of the plexus in more detail, with arrows indicating intraluminal pillars. (E) Quantification of pillars in the posterior 200 µm of the caudal venous plexus at 30 hpf shows no difference between wild types and rasa1−/− mutants [wild type (n=10) versus rasa1a−/− (n=11), P=0.09; N=3 experiments]; however, rasa1−/− mutants have significantly more pillars than wild types at 48 hpf [wild type (n=8) versus rasa1a−/− (n=9), P<0.0001; N=3 experiments]. Statistical analysis was carried out using one-way ANOVA with Sidak's correction. Data are mean±s.d. Scale bars: 10 µm.