Ablation of embryonic NC-Cms results in adult-onset hypertrophic cardiomyopathy and heart failure. a–c Whole-mount fluorescent images of adult hearts from embryonic NC-Cms ablation experiments (protocol in Fig. 2a). Red numbers represent percent of NC-Cms relative to total cardiomyocytes (GFP + and RFP + ), not total heart cells, quantified by flow cytometry (FACS) of dissociated adult hearts (Supplementary Figure 9). d FACS quantification of NC-Cms. Dots are individual hearts from each condition and bars = mean of individuals in each group (n = 4 + RE + GFP, DMSO and n = 5 + RE + GFP, MTZ) e–g Fluorescent microscopy sections of hearts from sibling individuals as in A-C. scale bar = 100 µm. h Quantification of area of ventricle covered in cardiomyocytes from sections similar to d–f. Dots represent sibling individuals from each condition pooled from biological replicates. Solid line = median, dashed line = mean. P-values computed by TukeyHSD on ANOVA (F(2,16) = 9.48). i-j Examples of single-cell cardiomyocyte morphology from dissociated control (i) and NC-Cm-ablated adult ventricles. Cells were cultured in chambers for 24 h to allow cell attachment, then fixed and stained with anti-GFP and DAPI and visualized by microscopy. Scale bar = 10 µm. k Quantification of individual cardiomyocyte area from chamber cultures as in “i, j”; n ≥ 25 cells per sample. P-value from standard T test. l Quantification of individual cardiomyocyte lengths from chamber cultures as in “i, j”. P-value from standard T test. m Example still image from movies of swim tunnel assays of individual male zebrafish. Red arrow indicates water current direction. n Swim trial assay provided incremental water speed increases of 0.05 m/s every 6 min (solid black line). Average assay results for DMSO control (light green, n = 4), MTZ control (dark green, n = 5) and NC-Cm-ablated (magenta, n = 8) adults. Data are amalgamated from n = 5 biological replicates. See Supplementary Movie 2. o Individual Ucrit results normalized to body length from assay in "m". See Methods for Ucrit calculation. Dots represent individual males from each condition. Solid line = median, dashed line = mean. P-values computed by TukeyHSD on ANOVA (F(2,13) = 24.65)