Fig. 1

Translational profiling of cardiomyocytes during zebrafish heart regeneration. (A) Tissue section indicating localization of EGFP-L10a fluorescence to cardiomyocytes in cmlc2:TRAP hearts. (B) Higher-magnification view of an uninjured cmlc2:TRAP ventricular apex. (C) Regeneration appears normal in cmlc2:TRAP ventricles 30 d after partial resection. Dashed line indicates approximate amputation plane. (Scale bars for A–C, 50 μm.) (D) RT-PCR of total or immunoprecipitated (TRAP) RNAs isolated from adult cmlc2:TRAP ventricles. β-actin1, hand2, cmlc2, ventricular myosin heavy chain (vmhc) and anf (also known as natriuretic peptide precursor A) are expressed in cardiomyocytes (CMs), and flk1 (endocardial), gata2a (hematopoietic), and tcf21 (epicardial) are noncardiomyocyte genes (Non-CMs). (E) Heat map from microarray indicating increased levels of Jak1/Stat3 pathway members in cmlc2:TRAP RNA samples at 1 dpa. (F) qPCR using RNAs immunoprecipitated from cmlc2:TRAP ventricles, confirming up-regulation of Jak1/Stat3 pathway members after injury. Expression levels were normalized to that of β-actin2, and further normalized to that of the uninjured sample. Data are mean ± SEM n = 3, *P < 0.05, **P < 0.01, ***P < 0.001, Student t test (unpaired, two-tailed). (G) Western Blots using total proteins extracted from uninjured and 1-dpa hearts, indicating increased protein levels of Stat3, phosphorylated Stat3 (P-Stat3), and Bcl2 at 1 dpa. Tubulin was used as a loading control (shown for Stat3 and P-Stat3 lanes).