IMAGE

Figure 4

ID
ZDB-IMAGE-230427-20
Source
Figures for McQuate et al., 2023
Image
Figure Caption

Figure 4

3 days post fertilization (dpf) hair cells (HCs) demonstrate immature mitochondrial architecture.

(A) Representative young HCs from a 3 dpf neuromasts (NM) (NM6, Figure 4—source data 2). Max mito shown in gold. Synaptic ribbons shown in purple. Scale bar = 8 µm. (A’) Representative older HCs from a 3 dpf NM (NM6, Figure 4—source data 2). Scale bar = 6 µm. (B) Comparison of total mitochondrial volume development (left) and average (right) between 3 dpf and 5–6 dpf HCs. On average (in µm3): 3 dpf: 14.4 ± 1.2; 5–6 dpf: 14.8 ± 0.8. Kolmogorov–Smirnov test, p=0.49. (C) Total HC volume for 3 dpf and 5–6 dpf HCs. (In µm3) 3 dpf: 210.1 ± 11.3; 5–6 dpf: 195.6 ± 7.2. Kolmogorov–Smirnov test, p=0.2. (C’) Ratio of total mitochondrial volume to HC volume. 3 dpf: 0.06 ± 0.003; 5–6 dpf: 0.07 ± 0.003. Kolmogorov–Smirnov test, p=0.41. (D) Comparison of the number of HC mitochondria over development (left) and on average (right) in 3 dpf and 5–6 dpf HCs. On average: 3 dpf: 25.0 ± 2; 5–6 dpf: 36.1 ± 1.6. Kolmogorov–Smirnov test, p=0.022. (E) Comparison of the median mitochondrial volume over development (left) and on average (right). On average (in µm3): 3 dpf: 0.3 ± 0.02; 5–6 dpf: 0.2 ± 0.01. Kolmogorov–Smirnov test, p=0.005. (F) Comparison of the max mito volume over development (left) and on average (right). On average (in µm3): 3 dpf: 3.8 ± 0.5; 5–6 dpf: 3.5 ± 0.4. Kolmogorov–Smirnov test, p=0.32. (G) Comparison of the max mito z-score in 3 dpf and 5–6 dpf HCs over development (left) and on average (right). On average: 3 dpf: 3.7 ± 0.3; 5–6 dpf: 4.1 ± 0.1. Standard unpaired t-test, p=0.21. (B–G) Solid line represents the standard linear regression for 3 dpf HCs. Dashed line represents standard regression for the 5–6 dpf HCs dataset as in Figure 2. Significance of the 3 dpf regression and difference with 5–6 dpf regression slope (S) are indicated. (H) The percentage of the max mito located within each quadrant of 3 dpf HCs represented as a heat map. Two HCs in the 3 dpf dataset lacked ribbons to provide a consistent HC lowest point and were not included in this analysis. (I) Summary of the heat map data shown in (H). Most apical quadrant (0–25%): 24.9 ± 8.9%; 25–50%: 37.2 ± 5.7%; 50–75%: 16.0 ± 4.2%; Most basal quadrant (75–100%): 22.0 ± 7.9%. Kruskal–Wallis test with Dunn’s multiple comparisons, nonsignificant. (J) Percentage of max mito located within the most basal quadrant for individual HCs. 3 dpf: 22.0 ± 7.9%, 5–6 dpf: 52.8 ± 4.4%. Kolmogorov–Smirnov test, p=0.017. Same cells as in (H, I). (B, D–G) 3 dpf data: n = 12 HCs, 2 NMs, 2 fish. 5–6 dpf data: n = 65 HCs, 5 NMs, 3 fish. (C, C’) 3 dpf data: n = 12 HCs, 2 NMs, 2 fish. 5–6 dpf data: n = 35 HCs, 3 NMs, 3 fish. (H–J) 3 dpf data: n = 10 HCs, 2 NMs, 2 fish. 5–6 dpf data: n = 65 HCs, 5 NMs, 3 fish. Where applicable, data are presented as the mean ± SEM.

Acknowledgments
This image is the copyrighted work of the attributed author or publisher, and ZFIN has permission only to display this image to its users. Additional permissions should be obtained from the applicable author or publisher of the image. Full text @ Elife