Figure 4

Figure 4

Homozygous scfd1^vcc44−/− mutants show cardiomyocyte ultrastructure defects at 3 dpf. (A) Representative low (upper panels) and high (lower panels) magnification electron micrographs of cross-sections of the thinnest part of the ventricular wall illustrating reduced wall thickness in scfd1 ^vcc44−/− mutants (black two-headed arrows). my: myocardial cell (yellow outline); e: endocardial cell (green outline); L: lumen. White arrow heads point to sarcomere z-discs. (B) Representative low (upper panels) and high (lower panels) magnification electron micrographs of cardiomyocyte myofibrils. White arrow heads point to sarcomere z-discs. m = mitochondrium. (C) Scatter graphs quantifying z-disc number (per 80 µm² region of interest (ROI); n = 8–10 ROIs per fish per genotype) and z-disc width (n = 116–129 measurements per fish per genotype) in wildtype (+/+) and scfd1^−/− mutant cardiomyocytes. Results analyzed using two-way ANOVA showing significant genotype effects. Significance if p < 0.05. Created with BioRender.com.