Fig. 5. Electron microscopy of the sciatic nerves of mutant animals. (A) Overview of P157 mutant sciatic nerve showing multiple remyelinating Schwann cell/axon units, a reactive non-myelinated Schwann cell (nm), and a macrophage (mp). (B) An arrow points to a dying myelinated Schwann cell with blebbing myelin sheath. Note that the denuded axon (a) is ensheathed by a reactive pro-myelinating Schwann cell (pm). (C) An early stage of remyelination with five myelin lamellae produced by a reactive myelinating Schwann cell (m). (D) Non-myelinated Schwann cell with a transcriptionally active nucleus (nm) associated with multiple small diameter axons. (E-F) Higher magnification of myelin sheaths of representative thickness surrounding medium (3.0-3.5 µm) diameter axons from control (48 lamellae) and mutant (13 lamellae) animals showing normal lamellae compaction. Scale bars: 2 µm in A-D, 200 nm in E-F.