Fig. 2

Tg(myl7:Twitch-4) reports cardiac Ca²⁺ oscillations and corrects motion artifacts in 3 dpf larvae. (A) Emission ratio images of Tg(myl7:ECFP-16aa-EYFP) and Tg(myl7:Twitch-4) moving hearts, and Tg(myl7:Twitch-4) heart stopped with 75 µM para-amino blebbistatin (PAB) (representative experiments). The atrial (At) and ventricular (Vt) systoles are shown. (B) Normalized emission ratio traces over time (R/R_Diast) calculated from larvae in A. The lowest diastolic ratio value (R_Diast) in each register was used for normalization. (C) Representative atrial and ventricular Ca²⁺ transients of a Tg(myl7:GCaMP)^s878 non-contracting heart (tnnt2a mopholinos) and a Tg(myl7:Twitch-4) beating heart. The plots show the rise and decay times of the atrial and ventricular Ca²⁺ transients (n = 9 larvae for Tg(myl7:GCaMP)^s878 from N = 2 experiments, and n = 7 for Tg(myl7:Twitch-4) from N = 5 experiments). Data are shown as the mean ± SD. A two-tailed unpaired Student's t-test was used.