Figure 4

Body curvature in slc6a9 mutant zebrafish.

(A) Axial curvature of slc6a9 mutant zebrafish at 7 dpf. The severity of the curvature is measured by θ angle. (B) Spinal curvature of slc6a9 mutant zebrafish at 21 dpf. (C) Curvature phenotype and micro-CT images of WT and slc6a9^m/+ zebrafish at adolescent stage (35 dpf). Images are shown in either side or dorsal view. A, anterior; P, posterior; L, left; R, right. (D) Axial curvature of WT zebrafish larvae treated with vehicle or GLYT1 inhibitor ALX 5407 (1 μM). (E) Quantification of axial curvature in WT and slc6a9^m/+ zebrafish treated with vehicle (Veh) or low-dose ALX5407 (ALX, 10 nM). Only 10% of slc6a9^m/+ fish showed axial curvature (θ ≥10°), whereas 10 nM ALX5407 induced axial curvature in 4.65% of WT and 34.9% of slc6a9^m/+ fish. (F) Quantification of axial curvature in slc6a9^m/m zebrafish with and without injection of 200 pg SLC6A9 WT or mutant (Y206F or R662W) mRNAs. Scale bars: 1 mm (A and D); 2 mm (B and C). In all charts, boxes show the median and IQRs with all individual data points superimposed. The number of analyzed fish and the penetrance of curvature (θ ≥10°) are quantified and indicated for each genotype. Unpaired Student’s t test (D) or 1-way ANOVA test (A, E, and F). **P < 0.01; ****P < 0.0001.