Family Identifier |
NMF335 |
Synonym(s) |
Scn8anmf335; Scn8a7J; B6;CByJ-Scn8a7J/J; JR#5463 |
Synopsis |
Hind and front limb movement impaired, head tossing. |
Gene Symbol |
Scn8a (View MGI Record) |
Gene |
Sodium channel, voltage-gated, type VIII, alpha polypeptide |
Allele Symbol |
Scn8anmf335 (View MGI Record) |
Allele |
neuroscience mutagenesis facility335 |
Abnormal Assay(s) |
Assay: Overt movement/posture
Domain(s): Movement/Neuromuscular Function
; Visible Mutants
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Phenotype Description |
In these mutants hind and fore limbs are affected, and the mice show a tottering walk, torso swaying, intense body tremor, and head tossing movements. The hind limbs are pulled closely to the body with impaired movement ability, front limbs show intermittently clonus like movements; when mice are lifted up, hind limbs do not spread apart, and the torso ventroflects backward. This overt phenotype can be observed at 3.7 weeks of age (+/- 1.2 weeks; n=91); ovarian transplants are needed to maintain a colony. Map position and phenotype similarities made NMF335 a candidate for complementation analysis with Scn8a; a mating of heterozygotes (NMF335 by C57BL/6J-Scn8amed-jo/J [JR#3799]) resulted in 4 mutants in a total of 8 progeny, confirming that NMF335 represents an allele of Scn8a.
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Pathology Report |
Standard pathology work-up was performed on five mutants (20 - 110 days of age). Neurogenic myopathy in the hind limb characterized by areas of very small muscle fibers with degenerating nerve fibers and replacement of muscle by fat was revealed in the three oldest mice (77, 78 or 110 days of age). A loss of granule cells in the cerebellum was also observed in these three mutants, with vacuolation of the ventral roots of the spinal cord noted in one. No abnormalities were observed in the two youngest animals (20 days of age). Additional pathology is in progress.
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HERITABILITY AND MAPPING INFORMATION
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Background Strain |
B6;CByJ |
Heritability Mode |
Recessive |
Heritability Status |
Proven; 2 different heterozygote x heterozygote matings resulted in 9 mutants in a total of 37 progeny.
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Chromosome |
15 |
Molecular Interval |
see Scn8a |
Map
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STATUS INFORMATION
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Mutant Status |
Cryopreserved Embryos
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Contact e-Mail Address |
nmf-mice@jax.org |