Mouse Genome Informatics
cx
    Atxn7tm1Hzo/Atxn7tm1Hzo
Kat2atm3.1Roth/Kat2a+

involves: 129 * 129S7/SvEvBrd
Key:
phenotype observed in females WTSI Wellcome Trust Sanger Institute
phenotype observed in males EuPh Europhenome
N normal phenotype
       
mortality/aging
• average life span of double mutants with 100 CAG repeats in Atxn7 is 10.7 +/- 7.5 months, and none of the mutants survive more than 1 year

behavior/neurological
• 66.6% of double mutants with 100 CAG repeats in Atxn7 are unable to stretch out their hindlimbs upon tail suspension and exhibit limb grasping at 6-8 months of age
• double mutants with 100 CAG repeats in Atxn7 exhibit ataxic gait
• at 8-9 months of age, but not 4 months of age, double mutants with 100 CAG repeats in Atxn7 walk with a significantly wider hind stance and dispersed fore- and hind-steps relative to wild-type mice, indicating an uncoordinated walking gait
• this uncoordinated walking gait is worse in these double mutants with 100 CAG repeats than in single homozygous or heterozygous Atxn7 mice with 100 CAG repeats
• gait of double mutants with 100 CAG repeats deteriorates over time into a severe stagger

nervous system
• Purkinje cells of double mutants with 100 CAG repeats in Atxn7 have smaller soma size
• double mutants with 100 CAG repeats in Atxn7 have fewer Purkinje cells at 9 months of age, but not at 5 months of age, indicating a loss of these cells
• Purkinje cell loss is significantly worse in lobule X of double mutants with 100 CAG repeats in Atxn7 than in other regions
• double mutants with 100 CAG repeats in Atxn7 have fewer Purkinje cells at 9 months of age, but not at 5 months of age, indicating a loss of these cells
• the cerebellar vermis of double mutants with 100 CAG repeats in Atxn7 shows cortical atrophy in the molecular layer of lobules VI, VII, and X at 8-9 months of age; atrophy is more severe in the double mutants than in single Atxn7tm1Hzo homozygotes with 100 CAG repeats
• by 2 months of age, double mutants with 100 CAG repeats in Atxn7 exhibit thinner inner segment layers of the retina, indicating photoreceptor degeneration
• by 2 months of age, double mutants with 100 CAG repeats in Atxn7 exhibit thinner outer segment layers of the retina, which is completely gone by 8 months of age, indicating photoreceptor degeneration
• double mutants with 100 CAG repeats in Atxn7 develop retinal atrophy, first observed at 1.5-2 months of age, indicating accelerated retinal degeneration compared to single Atxn7 homozygous mice with 100 CAG repeats

vision/eye
• by 2 months of age, double mutants with 100 CAG repeats in Atxn7 exhibit thinner inner segment layers of the retina, indicating photoreceptor degeneration
• by 2 months of age, double mutants with 100 CAG repeats in Atxn7 exhibit thinner outer segment layers of the retina, which is completely gone by 8 months of age, indicating photoreceptor degeneration
• double mutants with 100 CAG repeats in Atxn7 develop retinal atrophy, first observed at 1.5-2 months of age, indicating accelerated retinal degeneration compared to single Atxn7 homozygous mice with 100 CAG repeats
• in double mutants with 100 CAG repeats in Atxn7
• in double mutants with 100 CAG repeats in Atxn7
• double mutants with 100 CAG repeats in Atxn7 show progressive thinning of the outer nuclear layer and inner nuclear layer at 4 months of age that is drastic my 8 months of age

Mouse Models of Human Disease
OMIM IDRef(s)
Spinocerebellar Ataxia 7; SCA7 164500 J:179021