Phenotypes Associated with This Genotype

Genotype
MGI:5700052

• Allelic Composition: Tg(FXN)YG22Pook/0
• Genetic Background: B6J.Cg-Tg(FXN)YG22Pook

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

cellular

abnormal chromosome morphology ( J:91581 )

• mice show intergenerational instability of the GAA repeat sequence during transmission from parents to offspring through five to 8 generations

• F1 generation offspring do not display changes, but from the F2 generation onward, expansions or contractions are observed, increasing in size with subsequent backcrosses

• discreet bimodal expansions of the 190-GAA repeat units are observed in the F6-F7 generations onward; large hyperexpansions as seen in human samples are not detected

• somatic instability is age-related, with very little or no instability observed at 2 months, but at 9 and 12 months, smears of expanding GAA repeats are detected in cerebellar hemisphere, brain stem and cerebellum tissue

• 6-month old mice show repeat instability in CNS tissues, but not significantly greater than observed at 3 months

abnormal cell physiology ( J:91581 )

• instability is influenced by sex of transgenic parent, with overall bias toward intergenerational repeat contraction upon maternal transmission of transgene

• a parental age-related effect of GAA repeat instability is seen, with a bias towards expansions in offspring from male parents over 7 months of age