Fig. 6
The number of cardiomyocytes in tbx2ab morphants compared with wild-type is not different in the expanded atrium, but is relatively decreased in smaller ventricles. Hearts were imaged using embryos from the myl7:dsRed-nuc reporter line and numbers of cardiomyocytes counted manually in Z-stack sections. A: The top panel shows the quantification of data for wild-type (WT) or double morphant embryos (Mo) at 2 days postfertilization (dpf) or 3 dpf as indicated. Also as indicated, the cells were counted in the heart tube (HT) at 2 dpf or specifically in the ventricle (V) or atrium (A) at 3 dpf. The ** indicates statistical significance compared with wild-type, according to Student′s t-test, P < 0.01. B–E: Lower panels show representative images of wild-type (WT) or tbx2ab morphants (MO) at 2 dpf (B,D) and 3 dpf (C,E). For each measurement n is at least 10.