Defective ensheathment of motoric nerves in the Splotch mutant mouse

Acta Anat (Basel). 1990;138(3):246-53. doi: 10.1159/000146947.


Mouse embryos, homozygous for mutations at the Splotch locus, are afflicted with spina bifida and disturbances of neural-crest-derived tissues, e.g. spinal ganglia and pigment cells. The development of Schwann cells is affected in homozygotes to a varying degree along the rostrocaudal axis. In cervical motoric roots, nerves are associated with apparently normal Schwann cells. At the thoracic level, nerve-associated cells become more scarce and resemble the surrounding mesenchymal cells. They are not enveloped by a basal lamina and frequently show wide gaps between neighbouring cells. Lumbar motoric roots are mostly devoid of any associated cells. The Splotch mutant embryo is proposed to be a new animal model for the study of peripheral nerve ensheathment. The implications for Schwann-cell-mediated axon guidance are discussed.

MeSH terms

  • Animals
  • Embryo, Mammalian / innervation
  • Homozygote
  • Male
  • Mice
  • Mice, Mutant Strains / anatomy & histology*
  • Mice, Mutant Strains / genetics
  • Microscopy, Electron
  • Motor Neurons / cytology
  • Motor Neurons / physiology
  • Motor Neurons / ultrastructure*
  • Myelin Sheath / cytology
  • Myelin Sheath / physiology
  • Myelin Sheath / ultrastructure*
  • Neural Crest / embryology
  • Neural Crest / pathology
  • Phenotype
  • Schwann Cells / pathology