Family Identifier |
NMF31 |
Synonym(s) |
BALB/cByJ-Nmf31/J; JR#4122 |
Synopsis |
Heterozygotes have high threshold to electroconvulsive minimal clonic seizures. |
Gene Symbol |
Nmf31 (View MGI Record) |
Gene |
Neuroscience mutagenesis facility31 |
Allele Symbol |
Nmf31 (View MGI Record) |
Allele |
Neuroscience mutagenesis facility31 |
Abnormal Assay(s) |
Assay: Electroconvulsive threshold (ECT)
Domain(s): Epilepsy
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Phenotype Description |
Heterozygous mutants have a high threshold to electroconvulsive minimal clonic seizures (show relative resistance compared to the parental BALB/cByJ strain). When NMF31 mutant mice are stimulated transcorneally at 6 wks with 10 mA (females; or 10.5 mA at 13 wks) or 11.5 mA (males; or 12 mA at 13 wks), they, unlike BALB/cByJ mice, usually do not exhibit a robust minimal clonic seizure. However, mutants do not appear to be resistant to pentylenetetrazole (PTZ)-induced seizures. For example, when challenged with PTZ at 80 mg/kg (single subcutaneous dose) and observed for 30 minutes, the incidence of (7/16) or mean latency (9m, 21s) to generalized seizure was not significantly different from that of BALB/cByJ (6/10; 8min, 47s). Using other seizure endpoints (clonus, tonic hind limb extension) similar results were observed. This colony is currently maintained through matings of heterozygotes with +/+.
Homozygous mutants develop front- and hind limb spasms suggestive of seizure like behavior at approximately 3-6 days of age. These pups are virtually unable to move around, exhibit intermittent, intense front limb spasms, which move paws close to the chest,and hind limb spasms during which the hind limbs are completely extended backward, i.e. their hind limb position looks similar to that observed during maximal tonic hind limb extension seizures; they remain in this position for several seconds. The mutants appear to breath with difficulty and die a few days following onset of the overt phenotype.
NMF31 was mapped as a dominant trait in 50 N2 backcross mice using a seizure severity score combined from two independent tests as phenotype. The data were analyzed using the non-parametric scan function of MAPMAKER/QTL. The maximum z-score was at D1Mit100, but the 95% confidence interval for the peak location is approximately +/- 10 cM.
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Pathology Report |
Standard pathology work-up on 2 heterozygous mutants (206 or 462 days of age) revealed no abnormalities. There were no apparent defects in the brain; hippocampus appeared normal. |
HERITABILITY AND MAPPING INFORMATION
|
Background Strain |
BALB/cByJ |
Heritability Mode |
Dominant |
Heritability Status |
Proven; for the NMF31 dominant phenotype: 2 matings between an ECT-resistant mouse (putative homozygote) and wild-type BALB/cByJ produced 6 affected mice in a total of 13 progeny. |
Chromosome |
1 |
Molecular Interval |
D1Mit305 (+ 6 cM) - D1Mit33 (- 4 cM) |
Map
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STATUS INFORMATION
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Mutant Status |
Cryopreserved Embryos
|
Comments |
Please note: The majority of frozen NMF embryos is obtained through matings between homozygous (or heterozygous) mutant males and wild-type females; if recovery of mutants is requested, the mice will be shipped as soon as possible following wean without further phenotype or genotype testing. NMF embryos are supplied subject to the General Terms and Conditions of Sale posted at www.jaxmice.jax.org. For prices or further information, please inquire at srp@jax.org or nmf-mice@jax.org.
(8) NMF31 have been requested by and distributed to 1 investigator. |
Contact e-Mail Address |
nmf-mice@jax.org |