Figure 2

Representative light microscopy images of (A) wild-type (WT)/heterozygous (HET) siblings (B) vma21^Δ1/Δ1 (homozygous for a 1 base pair (bp) deletion in vma21), (C) vma21^{Δ14ins21/Δ14ins21} (homozygous for a 14 bp deletion with a 21 bp insertion in vma21), and (D) vma21^{Δ1/Δ14ins21} (a compound heterozygous line that contains both aforementioned mutations in vma21) zebrafish mutants in both the ventral and lateral positions at 5 days post fertilization (dpf). The red arrows on the panel showing the larvae in the ventral position indicate the greater level of melanophores (darker pigmentation) in the siblings in comparison to all the mutant lines. There is a decrease of xanthophores (the yellowish pigment) in the mutant lines (purple arrows) in comparison to all the siblings. The blue arrows show reduced swim bladder size within the mutant lines. Scale bars: 400 mm. (E) Bar graph showing a significant difference in body length between WT and vma21^Δ1/Δ1 mutants but not between WT and HETs or HETs and vma21^Δ1/Δ1 mutants at 5 dpf. n = 9–13/group. Data represented as mean ± SEM. Significance at *P < 0.05 (one-way ANOVA with Tukey’s multiple comparisons test). (F) Stacked bar graph of the percentage of WT vs vma21^Δ1/Δ1 mutants with inflated swim bladders at 5 dpf. n = 10–13/group. Significance at ****P < 0.0001 (Fisher’s exact test). (G) Kaplan–Meier curve showing percent survival of WT and vma21 mutant zebrafish starting from 0 dpf. Sample sizes: siblings n = 194, vma21^Δ1/Δ1n = 74, vma21^{Δ14ins21/Δ14ins21}n = 60, and vma21^{Δ1/Δ14ins21}n = 60. As represented in the graph: WT siblings (dark blue), vma21^Δ1/Δ1 (light blue), vma21^{Δ14ins21/Δ14ins21} (magenta), and vma21^{Δ1/Δ14ins21} (green). Significance at ****P < 0.0001 (Mantel–Cox test). (H–J) Free swim movement tracked over a ten-minute interval and (K–M) swim assay with the photoactive compound optovin to stimulate motor activity in 6 dpf larvae. Graphs from left to right show total time spent moving in seconds (s), total distance traveled in millimeters (mm), and average total velocity (mm/s) for each type of vma21 mutant with their respective WT/HET sibling controls. n = 24/group with three replicates. Data represented as mean ± SEM. Significance at ****P < 0.0001 (unpaired two-tailed t test). As represented in the graphs: siblings (dark blue dots), vma21^Δ1/Δ1 (light blue dots), vma21^{Δ14ins21/Δ14ins21} (magenta dots), and vma21^{Δ1/Δ14ins21} (green dots). Source data are available online for this figure.