Mice with this mutation of the sodium channel, voltage-gated, type VIII, alpha (Scn8a) gene exhibit a high incidence of spike wave discharges (SWD) and may be useful studies of human absence epilepsy.
Wayne Frankel, JAX
Mice that are homozygous for this chemically-induced allele exhibit small size, a weak and unsteady gait and a high incidence of spike wave discharges (SWD). On a mixed C57BL/6J and C3HeB/FeJ background, SWD burst frequency is recorded at 4-5 Hz. Homozygous mice die by 21 days, however, with additional care (see husbandry), mice can survive to 7 weeks. In mixed background heterozygotes, the SWD burst frequency is 7-9 Hz; SWD are characterized by high amplitude, significant duration and high frequency and occur between periods of locomotor activity. This mutant mouse strain may be useful in studies of human absence epilepsy.
In an attempt to offer alleles on well-characterized or multiple genetic backgrounds, alleles are frequently moved to a genetic background different from that on which an allele was first characterized. It should be noted that the phenotype could vary from that originally described. We will modify the strain description if necessary as published results become available.
This missense point mutation was generated by ethylnitrosourea (ENU) mutagenesis in C57BL/6J males in the ReproGenomics facility at The Jackson Laboratory. Mutagenized males were outcrossed to C3HeB/FeJ females; descendants of the mutagenized males were selected for neurological impairment. The mutation results in an G to T change at nucleotide 2785 altering the corresponding amino acid from phenylalanine to valine at position 929 (V929F) in domain 2 of the protein's pore region. This strain has been backcrossed to C3HeB/FeJ for a minimum of 12 generations.
|Allele Name||8 Jackson|
|Allele Type||Chemically induced (ENU)|
|Allele Synonym(s)||Scn8aV929F; V929F|
|Gene Symbol and Name||Scn8a, sodium channel, voltage-gated, type VIII, alpha|
|Strain of Origin||C57BL/6J|
|Molecular Note||ENU mutagenesis induced a G to T transition at position 2785 that results in the amino acid substitution of phenylalanine for valine at position 929 (V929F). This substitution occurs in the pore region of the protein.|
While maintaining a live colony, these mice are bred as heterozygotes. Mice homozygous for the mutation do not survive beyond 21 days unless kept with dams and fed with ground grain pellets. Under these conditions, mice survive to 7 weeks.
When using the C3Fe.B6-Scn8a8J/Frk mouse strain in a publication, please cite the originating article(s) and include JAX stock #012946 in your Materials and Methods section.