Fig. 3

Aberrant blood flow contributes to remodeling in nr2f1a mutant hearts.

a Ultrasound images from echocardiography were conducted on adult WT and nr2f1a^aco mutant fish. Anterior is to the right and ventral is up. Flow direction was pseudo-colored for ease of clearly discerning anterograde ventricular inflow (orange) and retrograde outflow (blue). Dashed lines denote the borders of heart. Yellow arrowhead indicates the location of regurgitation in nr2f1a^aco mutant heart. Still images were isolated from Supplementary Movies 1 and 2. n = 3 WT and nr2f1a^aco mutant fish were examined. b Confocal images of sagittal sections from 28 dpf WT and nr2f1a^aco mutant fish treated with either Captopril or DMSO (control). Scale bars – 100 μm. c Quantification of Elnb⁺ wall thickness (µm) at 28 dpf following Captopril treatments began at 14 dpf. Individual points on the graphs represent 10 measurements averaged from different regions of the SV in a single section (3 total sections per fish). (n = 5 for WT control and treated groups, n = 9 for nr2f1a^aco control group, n = 7 for nr2f1a^aco treated group). Statistical significance was calculated using an ordinary one-way ANOVA with multiple comparisons. Comparisons marked ****p < 0.0001. Source data are provided as a Source Data file. d Schematic outlining the juvenile exercise regimen beginning at 21 dpf. e Confocal images of sagittal sections showing immunostaining detecting Elnb (magenta), Amhc (green), and DAPI⁺ nuclei (blue) in the SV of unexercised (control) and exercised nr2f1a^aco mutant fish following 2 weeks of daily exercise. Scale bars − 50 μm. f Quantification of Elnb⁺ wall thickness at 35 dpf following 2 weeks of daily exercise (n = 4 fish per group). Individual points on the graphs represent 20 measurements averaged from different regions of the SV in a single section (3 sections per fish). An unpaired, two-sided Student’s t-test was used to assess statistical differences between exercised and unexercised nr2f1a^aco fish. Comparison marked **p = 0.0028. All error bars represent the mean +/− SEM. Source data are provided as a Source Data file.