Fig. 5 Examples of electron micrographs of SGCs in 2-month-old mice. aWT mouse (ms myelin sheath. b-d Mpv17-/- mouse showing a lamination and an invagination of the myelin sheath (arrows) into the cytoplasm of the Schwann cell, the accumulation of myelin-like structures, debris (asterisk) and onion blobs (double arrow) and occasionally the formation of cytoplasmic vacuoles (arrowheads). Bars 1 μm