Fig. 8. Cardiomyocyte proliferation is decreased in the tbx2ab morphants.
Embryos were pulse-labeled with BrdU, and after being fixed, were co-stained to detect BrdU+ cells (green) and MF20+ cardiomyocytes (red). Hearts were imaged and the yellow (double positive) cells counted (examples indicated by the small arrows). The top panels show representative wildtype (A) and morphant (B) embryos at ~32 hpf. The lower panel (C) shows quantification of the average BrdU+ cardiomyocytes, in each case from several randomly chosen embryos, n = 5. The ** indicates statistical significance compared to wildtype, according to Student’s t-test, p<0.02. This experiment was repeated several times and reproducibly showed significantly decreased relative levels of BrdU+ cardiomyocytes in morphants, although the actual number of double-labeled cells varies depending on the efficiency of BrdU labeling.