Hemogenic endothelium-based dorsal aorta is affected in fev-deficient embryos. (A) Expression of dll4 or ephrinB2 in the dorsal aorta of embryos injected with control MO or fevMO at 24 and 36 hpf, respectively. Expression of flt4 and msr in the cardinal vein of embryos injected with control MO or fevMO at 24 hpf. Anterior is to the left and dorsal is up. (B) qPCR analysis of ephrinB2 expression at 24 and 36 hpf in the dissected trunk region of embryos injected with control MO or fevMO (mean ± SD, n = 3, *P < .05). (C) Confocal microscopy of fli1a:GFP embryos at 60 hpf injected with control MO or fevMO. Red bracket denotes dorsal aorta, white bracket denotes cardinal vein. (D) Quantification of the artery/vein ratio of the lumen size between controls and fev morphants (mean ± SD, *P < .05). (E) Transverse section of fli1a:nGFP embryos injected with control MO or fevMO at 36 hpf. Dorsal aorta and cardinal vein are denoted by dotted circles in red and white, respectively. Nuclei were shown by 4,6 diamidino-2-phenylindole staining. (F) Statistics of EC numbers of the dorsal aorta wall on transverse sections in controls embryos and fev-morphants (mean ± SD, *P < .05).