Fig. 7

a–l Fluorescent in situ hybridization using hybridization chain reaction for prrx1a (a–f) and twist1a (g–l) expression combined with GFP fluorescence in etv2^ci32Gt; UAS:GFP heterozygous or homozygous embryos at the 18-somite stage. Maximum intensity projections of selected confocal z-stacks are shown. Note that both prrx1a and twist1a are expressed bilaterally, and their expression partially overlaps with GFP in the most lateral cells (arrows). GFP+ cells fail to coalesce into axial vasculature in etv2^{ci32Gt−/−} embryos. DA precursor vessel for the dorsal aorta, LDA lateral dorsal aortae. m, n Expression of foxd2 in the trunk region in etv2^ci32Gt heterozygous and homozygous embryos at the 18-somite stage. Note expression in the LPM region (arrows). Expression in the somites is also apparent. o, p In situ hybridization for GFP expression in etv2^ci32Gt+/− and etv2^{ci32Gt−/−}; UAS:GFP embryos at the 17–18-somite stage. GFP expression is observed in endothelial cell (EC, combined EC1 and EC2), endocardial (Endoc), endothelial progenitor cell (EPC), lateral plate mesoderm (LPM), tailbud and red blood cell (RBC) populations. Note the absence of EC and endocardial expression in (p). In all panels, the numbers display the number of embryos showing the expression pattern out of the total number of embryos analyzed in two replicate experiments.