Expressions of cardiomyogenesis-related genes in GH-treatedtbx5mutants. Expressions of (A)amhc, (B)vmhc,and (C)cmlc2in MO group zebrafish embryos were depressed throughout the developmental stages compared to WT zebrafish embryos. Expression of these thre cardiac myogenesis genes showed significant restorative effects in MOGH group embryos. On the other hand, expressions of cardiac myogenesis genes were not significantly affected in WTGH group embryos. The expression of amhc was restricted to the atrium in WT embryos (D), and its expression was depressed in MO group embryos (G). (J) MOGH group zebrafish embryos showed an ameliorating effect on restoration by the expression of amhc. The expression of vmhc was restricted to the ventricle in WT embryos (E) but showed minor expression in MO group embryos (H). (K) However, the expression of vmhc was significantly induced in the MOGH group. The expression pattern of cmlc2 was similar to that of vmhc, in that expression was low in tbx5-deficient embryos (I) but was restored in GH-treated embryos (L). Schematics indicate the location of the expressions of amhc (L), vmhc (M), and cmlc2 (N). Data are presented as the mean ± S.D. *p < 0.05 vs. WT. WT, wild-type embryos; MO, tbx5 knockdown; MIS, mismatched tbx5-MO-treated embryos; WTGH, WT embryos treated with growth hormone (GH); MOGH, tbx5-MO- and GH-treated embryos; a, atrium; v, ventricle.