FIGURE 7

FIGURE 7

Morpholino knockdown of acta2 causes vascular defects. (A–I) Representative bright field and fluorescent images of Tg (fli1a:EGFP)y1 embryos at 50-hpf. (B,C,E–H) Image of trunk regions taken at 50-hpf, with the vascular structures visualized by eGFP fluorescence and labeled ISV (intersegmental vessel) and DLAV (dorsal longitudinal anastomotic vessel) showed regular development in the embryo injected with control MO. Compared with control MO, embryos injected with acta2-MO present a lower number of incomplete ISVs and ectopic sprouts (F,I, asterisk). In control embryos, the parachordal vessels (PAV) form normally (C, red arrows). Compared with control, MO knockdown acta2 prevents the parachordal vessels (PAV) formation, the precursor to the lymphatic system. The boxed regions are shown at higher magnification in the bottom panels. (J–L) Quantification of the number of complete ISVs or mean length of ISVs shows a significantly decrease in acta2 morphants. Columns, mean; SEM (n = 10; ANOVA) ***P < 0.0001. hpf, hours post-fertilization.