Figure 7.

Pharmacologically inhibiting PAK1 activity in vivo alters zebrafish myelin internode length and number. A, B, Lateral view of zebrafish spinal cord above yolk sack extension. Tg(nkx2.2α:mEGFP; sox10:tagRFP) embryos were treated with a DMSO vehicle control (A) or the PAK1 inhibitor FRAX486 (B) from 48 to 72 hpf, then imaged. Square brackets indicate individual myelin internodes. Arrowheads indicate migrated oligodendrocytes. Scale bar, 50 µm. C, Quantification of dorsally migrated SOX10⁺ cells labeled by Tg(sox10:tagRFP). D, E, Quantification of myelin internode number (D) and length (E) represented as the mean/fish. Analysis was completed in IMARIS. n = 3 experimental replicas, 24 fish/treatment group. Wilcoxon rank-sum, internode number: r = 0.286, *p = 0.049, internode length: r = 0.619, ***p = 1.9e-05.