Phenotypes associated with this allele

• Allele Symbol: Nefm^tm1Ral
• Allele Name: targeted mutation 1, Robert A Lazzarini
• Allele ID: MGI:2180135
• Summary: 3 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Nefm^tm1Ral/Nefm^tm1Ral	either: (involves: 129S1/Sv * 129X1/SvJ * C57BL/6) or (involves: 129S1/Sv * 129X1/SvJ * C57BL/6 * Swiss Webster)	MGI:3851993
hm2	Nefm^tm1Ral/Nefm^tm1Ral	involves: 129S1/Sv * 129X1/SvJ	MGI:3851996
cx3	Nefh^tm1Ral/Nefh^tm1Ral Nefm^tm1Ral/Nefm^tm1Ral	involves: 129S1/Sv * 129X1/SvJ	MGI:3851998

Genotype
MGI:3851993

hm1

• Allelic Composition: Nefm^tm1Ral/Nefm^tm1Ral
• Genetic Background: either: (involves: 129S1/Sv * 129X1/SvJ * C57BL/6) or (involves: 129S1/Sv * 129X1/SvJ * C57BL/6 * Swiss Webster)

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

nervous system

nervous system phenotype ( J:47438 )

N • mice have normal cortical and subcortical structures

abnormal axon morphology ( J:47438 )

• radial growth of myelinated axons is severely inhibited unlike in wild-type mice

• axonal diameter is decreased compared to in wild-type mice

reproductive system

reproductive system phenotype ( J:47438 )

N • mice are fertile

behavior/neurological

behavior/neurological phenotype ( J:47438 )

N • mice exhibit normal motor coordination and strength

Genotype
MGI:3851996

hm2

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

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

Genotype
MGI:3851998

cx3

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

Hind limb paralysis develops in two year old Nefm^tm1Ral/Nefm^tm1Ral Nefh^tm1Ral/Nefh^tm1Ral mice

nervous system

abnormal axon morphology ( J:77656 )

• myelinated axons are smaller than normal

• myelinated axons of lumbar ventral and dorsal roots are irregular in shape and appear shrunken and collapsed unlike in wild-type mice

• occasionally ballooned axons are observed unlike in wild-type mice

• at 4 months, axonal diameters in ventral roots are decreased more than 30% unlike in wild-type mice

• at 2 years, axonal diameter in ventral roots is reduced to less than 25% of wild-type

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

• however, mice have normal numbers of axons

• axons in lumbar ventral roots are devoid of neurofilaments at 2 years of age

axon degeneration ( J:77656 )

• axonal degeneration is rarely observed

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

behavior/neurological

hindlimb paralysis ( J:77656 )

• in 4 of 5 mice at 2 years