Injection of actn2 MO leads to reduced cardiac function. A) Injection of actn2 MO reduces the shortening fraction, which is rescued by transgenic actn2 in Tg(ttna:actn2-egfp) fish. B) End-diastolic diameter is reduced in actn2 morphants. C) End-systolic diameter is comparable between WT fish and actn2 morphants. D) Heart rate is not affected by injection of actn2 MO. MO, actn2 MO fish; Tg, Tg(ttna:actn2-egfp) fish; MO+Tg, Tg(ttna:actn2-egfp) fish injected with actn2 MO; n, fish number; NS, not significant. *P < 0.05.