Phenotypes Associated with This Genotype

Genotype
MGI:3851996

• Allelic Composition: Nefm^tm1Ral/Nefm^tm1Ral
• Genetic Background: involves: 129S1/Sv * 129X1/SvJ

• ♀: phenotype observed in females
• ♂: phenotype observed in males
• N: normal phenotype

Lumbar root axon abnormalities in Nefm^tm1Ral/Nefm^tm1Ral and Nefh^tm1Ral/Nefh^tm1Ral Nefm^tm1Ral/Nefm^tm1Ral mice, but not Nefh^tm1Ral/Nefh^tm1Ral mice

nervous system

abnormal axon morphology ( J:77656 )

• myelinated axons are smaller than normal

• at 2 years of age, myelinated axons of lumbar ventral roots are irregular in shape and appear shrunken and collapsed unlike in wild-type mice

• at 2 years of age, ventral root axonal diameter is reduced by more than 50%

• morphologically normal axons in ventral roots exhibit a 20% decrease in axonal diameter at 2 years compared to in wild-type mice, similiar to that seen at 4 months of age

• mice have fewer large diameter axons in ventral roots than in wild-type mice

• however, mice have normal numbers of axons and dorsal lumbar roots appear normal

• axons in atrophic lumbar ventral roots of old mutants contain reduced numbers of neurofilaments and increased numbers of microtubules

• neurofilaments are less depleted in dorsal roots than ventral roots

axon degeneration ( J:77656 )

• axonal degeneration is rarely observed

• age-associated axonal atrophy in the lumbar ventral roots is observed after 1 year of age unlike in wild-type mice