Phenotypes Associated with This Genotype

Genotype
MGI:7523314

• Allelic Composition: Stmn2^em1Jmi/Stmn2⁺
• Genetic Background: C57BL/6N-Stmn2^em1Jmi

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

behavior/neurological

behavior/neurological phenotype ( J:337175 )

N • 1-year-old heterozygotes behave normally in the Von Frey test and accelerating rotarod test, indicating lack of sensory deficits

decreased grip strength ( J:337175 )

• heterozygotes develop a slowly progressive motor-selective behavioral defect by 1 year of age, with a greater reduction in the latency time (s) to fall from an inverted screen at 12 months than at 6 months of age

• however, motor function is normal at 3 months of age

nervous system

nervous system phenotype ( J:337175 )

N • at 12 months of age, sciatic (mixed), femoral (primarily motor), and sural (primarily sensory) nerves exhibit normal axon density; footpads show normal intraepidermal nerve fiber (IENF) density at 3 and at 12 months of age

abnormal neuron morphology ( J:337175 )

• heterozygotes exhibit a progressive, distal motor neuropathy with NMJ denervation, an early feature of ALS pathology

abnormal neuromuscular synapse morphology ( J:337175 )

• 1-year-old heterozygotes show denervation of lumbrical NMJs with a ~4-fold increase in the fraction of fully denervated postsynaptic AChR clusters; denervation occurs in roughly contiguous regions that are adjacent to well innervated portions of the same muscle

• however, lumbrical innervation is relatively normal at 3 months and no obvious synaptic denervation is noted in the more proximal EDL muscle

Mouse Models of Human Disease		DO ID	OMIM ID(s)	Ref(s)
amyotrophic lateral sclerosis		DOID:332	OMIM:PS105400	J:337175
motor peripheral neuropathy		DOID:2477		J:337175