Fig. 1 Knockdown of nkx2.5 and/or nkx2.7 causes prominent defects in cardiac chamber morphogenesis. (A–D) Frontal views, dorsal to the top at 52 hpf. MF20/S46 immunofluorescence distinguishes ventricular myocardium (red) from atrial myocardium (yellow). In comparison to wild-type embryos (A), injection of anti-nkx2.5 ATG MO (B) or anti-nkx2.7 ATG MO (C) causes subtle abnormalities in chamber size and shape. (D) Injection of anti-nkx2.5 and anti-nkx2.7 ATG MOs together reveals more striking defects in both ventricular and atrial morphology. (E,F) Lateral views of live embryos, anterior to the right, at 52 hpf. Other than their cardiac defects, pericardial edema, brain ventricle swelling, and jaw hypoplasia, nkx-deficient embryos appear morphologically normal.
Reprinted from Developmental Biology, 322(2), Targoff, K.L., Schell, T., and Yelon, D., Nkx genes regulate heart tube extension and exert differential effects on ventricular and atrial cell number, 314-321, Copyright (2008) with permission from Elsevier. Full text @ Dev. Biol.