Phenotypes Associated with This Genotype

Genotype
MGI:6194624

• Allelic Composition: Tg(GFAP-ATXN7*92Q)2521Als/0
• Genetic Background: involves: C3H/HeJ * C57BL/6J

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

behavior/neurological

limb grasping ( J:113150 )

• by 12 months of age, almost all mice show abnormal clasping response

impaired coordination ( J:113150 )

• mice fail the ledge test by 12 months of age

• mice exhibit progressive incoordination and ultimately an abnormal gait at 16-20 months of age

• mice show a shorter latency to fall times on the rotarod by 12 months of age, with most of these mice having difficulty moving their limbs rapidly and have lowered and flattened hips

• however, mice do not develop tremors, seizures, rigidity, or kyphosis

abnormal gait ( J:113150 )

• mice exhibit an abnormal gait at 16-20 months of age

nervous system

abnormal Bergmann glial cell morphology ( J:113150 )

• Bergmann glia shows swelling of radial processes

• Bergmann glia radial processes show more GFAP immunoreactivity

abnormal Purkinje cell morphology ( J:113150 )

• shrinkage of Purkinje cell bodies

Purkinje cell degeneration ( J:113150 )

• degeneration and dropout of Purkinje cells becomes apparent with disease progression

• mice exhibit vacuole formation in Purkinje cell dendrites in the molecular layer of the cerebellum, dendritic spine thinning, and Bergmann glia processes ensheathing Purkinje cells that lack subcellular organelles, indicating dark cell degeneration of Purkinje cells

abnormal Purkinje cell dendrite morphology ( J:113150 )

• mice show reductions in Purkinje cell dendritic arborization

abnormal cerebellar molecular layer ( J:113150 )

• molecular layer is atrophied

abnormal glial cell physiology ( J:113150 )

• uptake of glutamate by cultured Bergmann glia is reduced

• uptake of glutamate in cerebellar slices form 9 month old mice is reduced by 20-25%

• glutamate uptake capacity is reduced by approximately 40% in cerebellar synaptosomes

Mouse Models of Human Disease		DO ID	OMIM ID(s)	Ref(s)
spinocerebellar ataxia type 7		DOID:0050958	OMIM:164500	J:113150