Loss of nkx2.7 function in nkx2.5 mutants yields a more prominent ventricular deficiency. (A-F) Frontal views, anterior to the top, of MF20/S46 immunofluorescence, which distinguishes ventricular myocardium (red) from atrial myocardium (yellow), at 52 hpf. In comparison to wild type (A), injection of anti-nkx2.7 MO (D) causes subtle abnormalities in chamber morphology. (B,E) In the nkx2.5 heterozygote, mild atrial enlargement is observed following injection of anti-nkx2.7 MO. (C,F) Injection of anti-nkx2.7 MO into nkx2.5 mutants yields severe loss of ventricular tissue and dramatic expansion of Amhc (S46, yellow) throughout the heart. Arrow indicates ventricular remnant that includes Amhc localization.
|