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Phenotypes Associated with This Genotype
Genotype
MGI:5700053
Allelic
Composition
Fxntm1Mkn/Fxntm1Mkn
Tg(FXN)YG22Pook/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)YG22Pook mutation (2 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 6 months of age
• increase in weight from 6 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
• no sensory nerve or motor nerve conduction changes are seen in 9-14 month old mutants
• peripheral margination of the nucleus in many large neuronal cell bodies of the dorsal root ganglia, suggesting central chromatolysis
• between 6 months to 1 year, vacuoles are seen only in the dorsal root ganglia of the lumbar region, but after 1 year, vacuoles are seen within dorsal root ganglia of the cervical region, indicating a distal-to-proximal dying back neurodegeneration
• prominent, giant vacuoles (round, singular or multiple) are observed in large sensory neuronal bodies of dorsal root ganglia; peripheral margination of nucleus in many large neuronal cell bodies with or without vacuoles

behavior/neurological
• reduced performance on an accelerating rotarod from 3 months of age
• however, overt ataxia is not seen up to 2 years of age
• forelimb grip strength is decreased from 9 months of age
• mice show a decreased trend in locomotor activity in the open field from 6 months of age and a significant difference by 1 year of age

cardiovascular system
• iron deposition within the heart of 14-18 month old mice
• however, mice do not exhibit an increase in heart weight to body weight ratio, myofibril disarray, or fibrosis

cellular
• in 6-9 month old mice, oxidized proteins are increased in the cerebrum, cerebellum, heart, and skeletal muscle, with the most prominent increase in the cerebrum and cerebellum
• increase in lipid peroxidation in the heart

homeostasis/metabolism
• iron deposition within the heart of 14-18 month old mice
• however, mice do not exhibit an increase in heart weight to body weight ratio, myofibril disarray, or fibrosis
• level of the antioxidant enzyme CuZnSOD is decreased in the skeletal muscle by 40%

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


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
09/10/2019
MGI 6.14
The Jackson Laboratory