MYELIN DEFICIENCY (MD) - NEUROLOGIC MUTANT IN THE WISTAR RAT

Abstract

Myelin deficiency (md), a newly discovered neurologic mutation in the Wistar rat, is transmitted by an X-linked, recessive lethal gene. Male rats are affected, and the 1st symptom is a head tremor recognizable at 12-15 days of age. The tremors become generalized within a few days and disappear when the animal is at rest. In the later stages, from 17-21 days of age, the slightest disturbance will precipitate a generalized seizure. Pups die within 30 days after birth. The only gross postmortem change is a gray color of the spinal cord instead of its normally white appearance. Microscopic findings reveal total lack of myelin formation at all levels of the CNS.