Phenotypes Associated with This Genotype

Genotype
MGI:6191698

• Allelic Composition: Mpz^tm3.1Wra/Mpz^tm3.1Wra
• Genetic Background: FVB.129S2(Cg)-Mpz^tm1.1Wra

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

behavior/neurological

tremors ( J:241742 )

• mice exhibit a persistent tremor that is exacerbated during walking

ataxia ( J:241742 )

• slow, unsteady gait apparent by time of weaning at about 21 days of age

impaired coordination ( J:241742 )

• mice are unable to maintain balance on the rotating rod

cellular

increased Schwann cell proliferation ( J:241742 )

• Schwann cell proliferation is increased in sciatic nerves

• however, no differences in Schwann cell apoptosis are seen

increased endoplasmic reticulum stress ( J:241742 )

• marker analysis indicates endoplasmic reticulum stress

nervous system

increased Schwann cell proliferation ( J:241742 )

• Schwann cell proliferation is increased in sciatic nerves

• however, no differences in Schwann cell apoptosis are seen

abnormal Schwann cell morphology ( J:241742 )

• marker analysis indicates that Schwann cell development is impaired and that cells are arrested in the promyelinating stage

abnormal myelin sheath morphology ( J:241742 )

• 9% increase in sciatic nerve myelin period; the wider period is accounted for by an approximate 20 angstrom swelling at the extracellular apposition

• however, optic nerve myelin period is normal

• sciatic nerve segments have a coherence length of myelin reduced by about 60% and a period distortion that is twice as much as in wild-type, indicating more membrane packing irregularity

decreased myelin sheath thickness ( J:241742 )

• sciatic nerves exhibit very thin and poorly compacted myelin when it is present at all at 6 weeks of age

abnormal sciatic nerve morphology ( J:241742 )

• the number of myelinated axons is reduced in sciatic nerves

dysmyelination ( J:241742 )

• virtually no myelin is present in P2 mice, suggesting that myelination is delayed

• myelin abnormalities are similar at 2 weeks, 6 weeks, and 9 months of age, indicating no progression of myelin abnormalities after 2 weeks

• small diameter axons are less affected than large diameter axons

abnormal action potential ( J:241742 )

• evoked compound muscle action potential amplitudes are reduced

decreased nerve conduction velocity ( J:241742 )

• mice have severely slowed nerve conduction velocities at 6-8 weeks of age

Mouse Models of Human Disease		DO ID	OMIM ID(s)	Ref(s)
Charcot-Marie-Tooth disease type 1B		DOID:0110152	OMIM:118200	J:241742