Phenotypes associated with this allele

• Allele Symbol: Nrcam^m1J
• Allele Name: mutation 1, The Jackson Laboratory
• Allele ID: MGI:5444298
• Summary: 3 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Nrcam^m1J/Nrcam^m1J	B6.Cg-Nrcam^m1J/GrsrRwb	MGI:5882403
cx2	Nrcam^m1J/Nrcam^m1J Sh3tc2^m1J/Sh3tc2^m1J	B6.Cg-Nrcam^m1J Sh3tc2^m1J/GrsrRwb	MGI:5882405
cx3	Gars1^C201R/Gars1^+ Nrcam^m1J/Nrcam^m1J	involves: BALB/cAnN * C3H/HeH * C57BL/6J	MGI:5882408

Genotype
MGI:5882403

hm1

• Allelic Composition: Nrcam^m1J/Nrcam^m1J
• Genetic Background: B6.Cg-Nrcam^m1J/GrsrRwb

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

behavior/neurological

impaired coordination ( J:240096 )

• poor performance on a rotarod test

cardiovascular system

heart block ( J:240096 )

• conduction block that is intermediate between wildtype and that found in mice additionally homozygous for a Sh3tc2 null allele

nervous system

nervous system phenotype ( J:240096 )

N • no overt neuromuscular phenotype detected, and no changes in axon diameter, myelin thickness, or axon number

abnormal node of Ranvier morphology ( J:240096 )

• split nodes with two distinct bands of NaV1.6 and AnkyrinG are found in 6.6% (+/-2.8%) of nodes assessed in sciatic nerve

abnormal myelination ( J:240096 )

• myelin is more tightly wrapped than normal as assessed on femoral motor nerves

decreased nerve conduction velocity ( J:240096 )

• slightly decreased in adult homozygotes

Genotype
MGI:5882405

cx2

• Allelic Composition: Nrcam^m1J/Nrcam^m1J; Sh3tc2^m1J/Sh3tc2^m1J
• Genetic Background: B6.Cg-Nrcam^m1J Sh3tc2^m1J/GrsrRwb

behavior/neurological

paralysis ( J:240096 )

• progressive paralysis and muscle wasting, leading to death by 5 months of age, but in mice homozygous for one allele and heterozygous for the other this phenotype is not observed

cardiovascular system

heart block ( J:240096 )

• conduction block with the proximal integrated compound muscle action potential reduced by 35% relative to that of the distal

nervous system

abnormal neuromuscular synapse morphology ( J:240096 )

• although single mutants have normal neuromuscular junctions, double homozygotes have extensive fragmentation, sprouting of nerve terminals, and extrasynaptic acetylcholine receptor expression in the neuromuscular junctions of the plantaris muscle at 3.5 months of age, but not at 2.5 months of age

abnormal nerve conduction ( J:240096 )

• double homozygotes have reduced action potential propagation with distance and when synaptic transmission at the neuromuscular junction was assessed by two-electrode voltage clamp, five of 10 fibers assessed failed to produce an evoked response despite the presence of spontaneous mini excitatory postsynaptic currents.

decreased nerve conduction velocity ( J:240096 )

• the adult compound homozygote has less than half normal sciatic nerve conduction velocity, a more severe diminution than that of either single homozygote, although the myelin thickness is comparable to that of Sh3tc2 null mutants

mortality/aging

premature death ( J:240096 )

• by 5 months of age

muscle

muscular atrophy ( J:240096 )

Genotype
MGI:5882408

cx3

• Allelic Composition: Gars1^C201R/Gars1⁺; Nrcam^m1J/Nrcam^m1J
• Genetic Background: involves: BALB/cAnN * C3H/HeH * C57BL/6J

behavior/neurological

tremors ( J:240096 )

impaired coordination ( J:240096 )

• poor motor performance compared with controls, but no progression to paralysis

muscle

muscle hypoplasia ( J:240096 )

• muscles in mice with this compound genotype are smaller than that of either parental mutant alone

nervous system

abnormal innervation pattern to muscle ( J:240096 )

• decreased neuromuscular junction occupancy with an increase in partial innervation as well as some denervation

abnormal axon morphology ( J:240096 )

• reduced axon size in the motor branch of the femoral nerve, similar to that of glycyl-tRNA synthetase mutant mice wildtype for neuronal cell adhesion molecular

abnormal neuromuscular synapse morphology ( J:240096 )

decreased nerve conduction velocity ( J:240096 )

• nerve conductance velocity, assessed in adult sciatic nerve, is reduced further than that in either single parental mutant