Phenotypes associated with this allele

• Allele Symbol: Sh3tc2^m1J
• Allele Name: mutation 1, The Jackson Laboratory
• Allele ID: MGI:5444299
• Summary: 2 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Sh3tc2^m1J/Sh3tc2^m1J	B6.Cg-Sh3tc2^m1J/GrsrRwb	MGI:5752850
cx2	Nrcam^m1J/Nrcam^m1J Sh3tc2^m1J/Sh3tc2^m1J	B6.Cg-Nrcam^m1J Sh3tc2^m1J/GrsrRwb	MGI:5882405

Genotype
MGI:5752850

hm1

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

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

behavior/neurological

tremors ( J:240096 )

decreased grip strength ( J:240096 )

cardiovascular system

heart block ( J:240096 )

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

nervous system

nervous system phenotype ( J:240096 )

N • no abnormalities found in the neuromuscular junctions of the plantaris muscle

abnormal Schwann cell morphology ( J:229591 , J:240096 )

• supernumerary Schwann cell processes in peripheral motor and sensory nerves (J:229591)

• supernumerary Schwann cell processes in the adult but no decrease in myelinated axon number or axon diameter (J:240096)

decreased myelin sheath thickness ( J:229591 , J:240096 )

• thin myelin sheath observed in peripheral motor and sensory nerves are due to a reduced number of myelin wraps and not changes in myelin packing (J:229591)

• reduced myelin thickness of the femoral nerve in adults (J:240096)

demyelination ( J:240096 )

decreased nerve conduction velocity ( J:229591 , J:240096 )

• mice exhibit reduced nerve conduction velocities by 3 months of age (J:229591)

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 )