Deficiency of MicroRNA-23-27-24 Clusters Exhibits the Impairment of Myelination in the Central Nervous System

Figure 5

Evaluation of myelin sheath by electron microscopy. Wild-type (WT) and miR-23-27-24 cluster knockout (KO), 150-200 axons per mouse, per group. (a) Electron micrograph of the transverse section of the spinal cord in WT and KO mice at 4 weeks, 10 weeks, and 12 months of age. Scale bars: 2 μm. (b) The ratio of the diameter of the axon without myelin sheath to the diameter of the axon with myelin sheath (G-ratio) was used to evaluate the thickness of the myelin sheath. G-ratio in 12-month-old mice was significantly lower than that in 4- and 10-week-old WT and KO mice. G-ratio in 10-week-old WT mice was significantly lower than that in 4-week-old WT mice. G-ratio in KO mice was significantly higher than that in WT mice at all ages. Compared to 4-week-old. Compared to 10-week-old. ^†Comparison between WT and KO mice, . (c) There was no significant difference in axon diameter between WT and KO mice or between mice of different ages. (d) Regardless of the axon diameter, the G-ratio in KO mice was higher than that in WT mice at all ages.

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