Phenotype Image Detail

Image

Caption

Cytoplasmic inclusions in compact CNS myelin of Mal^tm1Nsw/Mal^tm1Nsw mice. EM of optic nerves from wild-type (WT) and age-matched Mal^tm1Nsw/Mal^tm1Nsw (ko) mice in adult (A-D) and during development (E and F). A: Myelin sheaths in wild-type mice lack oligodendrocytic cytoplasmic inclusions in compact myelin, and the majority of sheaths display a well-developed periaxonal cytoplasmic collar that spans more than half of the axonal circumference. In mutant mice, in contrast, many axons (ax1-ax14 in B; ax1-ax3 in C; and ax4 in D) are surrounded by sheaths that contain cytoplasmic inclusions in compact myelin. Most sheaths lack a well-developed periaxonal cytoplasmic collar (B-D). Close inspection of mutant sheaths at higher magnification suggests that some cytoplasmic inclusions are indicative of the presence of two myelin sheaths concentrically surrounding the same axon. Inner and outer sheaths are either spiraling in opposite directions (ax1 and ax2 in C; ax4 in D) or in the same direction (ax3 in C). C and D: 1 and 3 indicate the inner tongue process of the inner and outer myelin sheath, respectively; 2 and 4 indicate the external tongue process of the inner and outer myelin sheath, respectively. E and F: EM analysis of optic nerve during development at P20. Note the similar extent of myelination in wild-type and mutant mice. Inclusions of cytoplasm within the compact myelin of mutant mice were frequent at P20 (F, arrows). Although myelination in mutant mice appeared less homogeneous, no difference in myelin sheath thickness or in number of myelinated fibers was observed between genotypes. Bars: A, 0.5 m; B, E, and F, 1 m; C and D, 0.2 m.

Copyright

This image is from Schaeren-Wiemers N, J Cell Biol 2004 Aug 30;166(5):731-42, and is displayed under the terms of the Creative Commons Attribution-Noncommercial-Share Alike 3.0 Unported LicenseJ:92517

Associated Alleles

Symbol	Name
Mal^tm1Nsw	myelin and lymphocyte protein, T cell differentiation protein; targeted mutation 1, Nicole Shaeren-Wiemers

Associated Genotypes

Allelic Composition	Genetic Background
Mal^tm1Nsw/Mal^tm1Nsw	involves: 129P2/Ola