Fig. 1

VE-Cad MO prevents VE-cadherin expression and impairs cardiac formation.

Western blot analysis was performed on protein lysates collected from 24-hour old uninjected (Blot, left), VE-Cad MO injected (Blot, center) and control MO injected (Blot, right) embryos were probed with antibody directed against human VE-cad (110 kDa). Mouse β-actin antibody is shown as a loading control (42 kDa). Brightfield microscopy was used to obtain images of 48–96 hpf embryos injected with control MO (left column) and VE-cad translation-blocking MO (right column). At 48 hpf (a–d), low power images show similar overall body morphology between control (a) and VE-cad MO injected (b) embryos (40x). High power views of the thoracic region (d) show pericardial edema, atrial dilation and blood pooling at the sinus venosus 200x). Tracings of the atrial (blue) and ventricular (red) size and orientation are also shown. By 72 hpf (e–h), pericardial edema is prominent in knockdown embryos and the cardiac chambers retain a linear orientation (f,h) in contrast to control embryos (e,g). Control embryos appear normal at 96 hours (i,k) with normal overlap of the 2 chambers, however VE-cad MO embryos show significant pericardial edema, improper cardiac looping, and circulatory arrest (j,l).