Fig. S1

Expression analysis for TGF-β family genes and generation of mstnb GOF and inhbaa LOF lines. (a) RT–qPCR for mstnb, tcf21 (wall-specific), nppa (trabecular-specific) and hey2 (wall-specific) expression in Laser micro dissected wall and trabecular tissues from adult zebrafish heart sections (n=3 hearts assessed in 2 technical replicates). (b) RT–qPCR for TGF-β family ligand gene expression at 6 dpci compared to sham injured hearts (n=2 x 3 cardiac ventricles assessed as 2 biological and 2 technical replicates). (c) RT–qPCR for TGF-β family receptor gene expression at 6 dpci compared to sham injured hearts (n=2 x 3 cardiac ventricles assessed as 2 biological and 2 technical replicates). (d) Schematic representation of CM-specific mstnb OE transgene, Tg(myl7:mstnb-2A-H2B-EGFP). (e) Heart of 72 hpf mstnb OE larva in Tg(myl7:nlsDsRedExpress) background (native fluorescence). (f) Section of mstnb OE adult heart in Tg(myl7:nlsDsRedExpress) background; α-DsRed (red), α-GFP (green). (g) RT–qPCR for mstnb expression analysis in wild-type sibling and mstnb OE adult hearts (n=2 x 3 cardiac ventricles assessed as 2 biological and 2 technical replicates). (h- k) mstnb OE adult hearts and Hematoxylin and Eosin (H&E) staining of heart sections show no apparent abnormalities. (l-n) inhbaa TALEN designed to target TGF-β propeptide domain encoded by exon 1 was generated (l), a 17 bp frameshift deletion (inhbaa^bns37) was identified (m) and is predicted to cause the formation of truncated Inhbaa (n). Red number indicates the last native amino acid before the frameshift mutation; green number indicates the last amino acid before stop codon. (o) RT–qPCR for inhbaa expression analysis in inhbaa^+/+ and inhbaa^-/- adult hearts (n=2 x 3 cardiac ventricles assessed as 2 biological and 2 technical replicates). (p-s) inhbaa^-/- adult hearts and H&E staining of heart sections show no apparent abnormalities. (data are mean ± s.e.m., ns: no significant changes observed, *P ≤ 0.05, **P ≤ 0.01 and ****P ≤ 0.0001 - Student’s t-test, two-tailed). Scale bars, 100 μm. vent., ventricle; atr., atrium; dpf, days post fertilization; mpf, months post fertilization.