FIGURE 3.

Expression of human COG4^p.G516R impairs zebrafish early development and chondrocyte intercalation. (A,B) Expression of COG4^p.^G516R in zebrafish causes gastrulation defects and shortened body axis. (A) Lateral view of representative embryos. Anterior to the top. Compared to the control construct hsp70l:mCherry and COG4^WT, embryos expressing COG4^p.G516R show an axis extension defect at 10 hpf. White arrow points to the head region, and the black arrow points to the tailbud. Expression of COG4^p.G516R mRNA causes similar results. (C) Graphs show the measured body length of each group at 3 and 6 dpf. The data are presented as mean ± SD. One-way ANOVA with Tukey’s multiple comparison tests was applied. ^****p < 0.0001; ns, not significant. (D) Expression of COG4^p.G516G causes craniofacial abnormalities. Ventral view of representative Meckel’s cartilage of zebrafish larvae at 4 dpf after WGA staining and imaged by a confocal microscope. Dotted circular lines highlight chondrocyte cell shape and their relative configuration with each other. (E) Graphical representation of the length-to-width ratio of chondrocytes in the region of interest, yellow box in (D). Individual cell length-to-width ratio was measured in three representative Meckel’s cartilage images of each group. The data are presented as mean ± SEM. One-way ANOVA with Tukey’s multiple comparison tests was applied. ^****p < 0.0001; ns, not significant. Experiments were performed in triplicates with similar results.