Fig. 5

Mild alteration of the myocardium under homeostatic conditions in cox7a1−/− adult zebrafish (A) Representative section of acid fuchsin orange G (AFOG) staining of 5 months postfertilization (mpf) zebrafish hearts (n = 8). Scale bars, 250 μm. (B–G) Echocardiography of adult male cox7a1−/− fish. (B) Representative images of the recorded echocardiography of adult males (n = 10). (C) Percentage of ejection fraction, (D) stroke volume, (E), percentage of fractional shortening, (F) heart volume, (G) percentage of observed fish with arrythmias (dark colored bars). Shown are measurements of individual animals, median and quartiles. Unpaired t test. ns, non-significant. (H–K) Transmission electron microscopy images of adult heart section showing sarcomeres (shown are representative images of a total of n = 3 males per group). (H) Representative images, measurements of (I) sarcomere thickness, (J) sarcomere length, and (K) angle between sarcomeres. Sarcomeres were measured in 3–5 different areas per sample. Each biological replicate is represented in a different color tone. Shown are also median and quartiles. ns, non-significant. Unpaired t test. Scale bars, 2 μm. (L and M) Quantitative proteomics analysis comparing hearts from adult cox7a1−/− and wild-type zebrafish (n = 3 technical replicates; each being a pool of n = 5 biological samples from 5 mpf males). (L) Volcano plot of detected proteins with log fold-change (LFC) > ±1 p value < 0.05. (M) Heatmap of proteins differentially expressed between cox7a1+/+ (WT) and cox7a1−/− associated to the keywords “actin” and “muscle.” Scale shows expression as normalized expression levels. Numbers indicate proteins associated to other pathways (see Data S3 ). See also Data S3 and S4 .