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Phenotypes Associated with This Genotype
Genotype
MGI:6508400
Allelic
Composition
Spg21tm1Mchan/Spg21tm1Mchan
Genetic
Background
Not Specified
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Spg21tm1Mchan mutation (0 available); any Spg21 mutation (19 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
behavior/neurological
• in the hind limb clasp test, 6-month old mice splay their hind limbs inwardly and grasp solid objects and 12-month old mice have about 2 times higher hind limb clasping
• 12-month old mice exhibit a higher number of foot slippages than 6-month old mice on a beam walk test (J:302080)
• the mean latency to fall in the ledge test is shorter in both 6- and 12-month old mice compared to wild-type mice, with 12-month old mice showing greater difficulty walking along the ledge and slipping and falling about 2 times more than wild-type mice (J:302080)
• in the narrow beam-walking test, mice exhibit an increase in the number of slips as early as 2-6 months of age and after 12 months of age, mice show progressive difficulty in traversing the beam, with a delay in completing the task (J:302256)
• mice show slight dragging of the hind limbs at several months of age which progressively worsens with age

cellular
• cortical neurons grown on poly-D-lysine-coated plates show only marginal changes in morphology during the first 3 days and show reduced rate of formation of ganglial networks at 96 hours, indicating reduced growth of cortical neurons
• cortical neurons fail to respond to EGF-induced growth and maturation
• however, proliferation rate of cortical neurons in response to EGF is similar to wild-type neurons

nervous system
• cortical neurons grown on poly-D-lysine-coated plates show a reduction in the number of neurons with axonal branches (J:302080)
• cortical neurons form fewer branches per axon (J:302080)
• cerebral cortical neurons grown on glass cover slips show increased axonal branching (J:302256)
• however, the number of primary dendrites is unchanged and axon elongation is normal and mice show no evidence of white matter disease (J:302256)
• cortical neurons grown on poly-D-lysine-coated plates show only marginal changes in morphology during the first 3 days and show reduced rate of formation of ganglial networks at 96 hours, indicating reduced growth of cortical neurons
• cortical neurons fail to respond to EGF-induced growth and maturation
• however, proliferation rate of cortical neurons in response to EGF is similar to wild-type neurons
• axonal termini of cortical neurons appear as fringed or feathered with minute processes
• however, axonal length of cortical neurons does not differ from wild-type neurons

Mouse Models of Human Disease
DO ID OMIM ID(s) Ref(s)
Mast syndrome DOID:0060245 OMIM:248900
J:302256


Contributing Projects:
Mouse Genome Database (MGD), Gene Expression Database (GXD), Mouse Models of Human Cancer database (MMHCdb) (formerly Mouse Tumor Biology (MTB), Gene Ontology (GO)
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last database update
08/03/2022
MGI 6.21
The Jackson Laboratory