Quaking*shiverer double-mutant mice survive for at least 100 days with no CNS myelin

Mice expressing mutations that produce CNS hypomyelination often die premat urely: the mo re severe the hypomyelination, the shorter the life span. How ever, we have previously described jimpy-msd mice that survive twice as lon g as usual; although they acquire significantly increased amounts of myelin , they still succumb long before their unaffected littermates. This result contradicts any postulated causal relationship between extent of CNS hypomy elination and premature death of the animal. Here we have addressed this qu estion in another way, by using an animal model that does not involve a pro teolipid protein (Plp) gene mutation. We demonstrate that quaking * shivere r double-mutant mice can survive for at least 100 days without any CNS myel in whatsoever. Therefore, at least for a mouse, absence of CNS myelin is no t lethal per se. Copyright (C) 2000 S. Karger AG, Basel.