Figure 1.

Figure 1.

Age-dependent myelin maintenance defects are present in dock1 MUTs. (A–C) TEM of cross-sections of ZMBs from 4-mo-old WT dock1^+/+, HET dock1^stl145/+, and homozygous dock1^{stl145/stl145} MUT zebrafish. (D–F) TEM micrographs of ZMBs from 12-mo-old WT dock1^+/+, HET dock1^stl145/+, and homozygous dock1^{stl145/stl145} MUT zebrafish, with homozygous MUTs exhibiting myelin outfoldings (red arrow). (G and H) Higher-magnification TEM micrographs of ZMBs from 12-mo-old homozygous dock1^{stl145/stl145} MUTs showing abnormally myelinated axons (red arrows), features rarely seen in WT dock1^+/+ or HET dock1^stl145/+ animals. (I) Quantification of the percent of axons with abnormal myelin profiles, observed by TEM, in WT dock1^+/+ versus homozygous dock1^{stl145/stl145} MUTs at 4 and 12 mo old, n = 10 (WT dock1^+/+ 4 mo old), 10 (dock1^{stl145/stl145} MUT 4 mo old), 10 (WT dock1^+/+ 12 mo old), and 10 (dock1^{stl145/stl145} MUT 12 mo old). Here, and in all figures, the X symbol in the graph denotes a data point corresponding to the representative image shown. (A–H) Scale bar = 1 µm. (I) Two-way ANOVA with Tukey’s multiple comparisons test. ***P < 0.001; ns, not significant.