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Phenotypes associated with this allele
Allele Symbol
Allele Name
Allele ID
Tg(FXN)YG8Pook
transgene insertion YG8, Mark A Pook
MGI:3797739
Summary 2 genotypes
Jump to Allelic Composition Genetic Background Genotype ID
cx1
Fxntm1Mkn/Fxntm1Mkn
Tg(FXN)YG8Pook/0
involves: 129/Sv * C57BL/6 * CBA MGI:3797844
tg2
Tg(FXN)YG8Pook/0 B6.Cg-Tg(FXN)YG8Pook MGI:3797786


Genotype
MGI:3797844
cx1
Allelic
Composition
Fxntm1Mkn/Fxntm1Mkn
Tg(FXN)YG8Pook/0
Genetic
Background
involves: 129/Sv * C57BL/6 * CBA
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Fxntm1Mkn mutation (13 available); any Fxn mutation (30 available)
Tg(FXN)YG8Pook mutation (6 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
mortality/aging
N
• embryonic lethality seen for Fxn-deficient embryos is recued by transgene expression; normal numbers of offspring are recovered and mice show normal lifespans, surviving to at least 2 years of age

growth/size/body
• significant increase is observed from 9 months of age

nervous system
N
• no neuronal histopathology is detected in cerebellar Purkinje cells or granule cells, and no abnormalities in brain or spinal cord regions are seen
• cerebellum shows increased induction of inflammation in response to lipopolysaccharide (LPS) treatment
• at 20 months, some axons in lumbar DRG display swelling and secondary demyelination
• some regions of lumbar DRG are devoid of cytoplasmic organelles at 20 months
• degenerating large DRG neurons are detected, with evidence of oxidative stress and mitochondrial dysfunction
• in mice >1 year of age, vacuoles are observed within the DRG in the cervical region
• 16% of cervical DRG sections display vacuoles
• prominent, giant vacuoles (round, singular or multiple) are observed in large sensory neuronal bodies of DRG in mice between 6 and 12 months, but not in controls; peripheral margination of nucleus in many large neuronal cell bodies with or without vacuoles
• 70% of lumbar DRG sections examined have vacuoles
• slight decrease in sensory action potential in 20-months old mice is detected, suggesting a mild progressive sensory neuropathy
• slight decrease in sensory nerve conduction velocity in 20-months old mice is detected, suggesting a mild progressive sensory neuropathy

behavior/neurological
• reduced rotarod performance is exhibited by mice from 3 months of age
• mice show a significant decrease in locomotor activity in the open field from 6 months of age

cardiovascular system
• patches of lipofuscin deposition and lysosymes, with accumulation of dispersed free glycogen disrupt regular arrangement of mitochondria within cardiomyocytes at 20 months

cellular
• mitochondrial respiratory chain function is decreased compared to controls
• in 6-9 month old animals, levels of oxidized proteins are increased, most significantly in cerebrum and cerebellum, with other significant increases seen in heart and skeletal muscle
• increased lipid peroxidation is detected in heart samples

muscle
• patches of lipofuscin deposition and lysosymes, with accumulation of dispersed free glycogen disrupt regular arrangement of mitochondria within cardiomyocytes at 20 months

homeostasis/metabolism
• aconitase activity is decreased to <70% of wild-type levels

immune system
• cerebellum shows increased induction of inflammation in response to lipopolysaccharide (LPS) treatment

Mouse Models of Human Disease
DO ID OMIM ID(s) Ref(s)
Friedreich ataxia DOID:12705 OMIM:229300
OMIM:601992
J:114840 , J:216422




Genotype
MGI:3797786
tg2
Allelic
Composition
Tg(FXN)YG8Pook/0
Genetic
Background
B6.Cg-Tg(FXN)YG8Pook
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Tg(FXN)YG8Pook mutation (6 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
cellular
N
• instability is influenced by sex of transgenic parent, with overall bias toward intergenerational repeat expansion upon paternal transmission of transgene
• 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 82- and 190-GAA repeat units are observed in the F4-5 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 3 months, smears of expanding GAA repeats are detected in cerebellar hemisphere, brain stem, cerebellum, and spinal cord tissue
• 6-month old mice show repeat instability in CNS tissues, but not significantly greater than observed at 3 months





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
10/08/2019
MGI 6.14
The Jackson Laboratory