spkw2^C57BL/6J
QTL Variant Detail

Summary

• QTL variant: spkw2^C57BL/6J
• Name: spike wave 2; C57BL/6J
• MGI ID: MGI:3580144
• QTL: spkw2 Location: unknown Genetic Position: Chr8, Syntenic

Variant origin

• Strain of Specimen: C57BL/6J

Variant description

• Allele Type: QTL
• Mutation: Undefined
• Mutation details: This allele confers increased incidence of spike wave discharges in the brain when in the presence of spkw1. (J:98638)
• Inheritance: Not Specified

Notes

This allele interacts with spkw2. Animals with the highest incidence of spike wave discharges are homozygous for C3H/HeJ-derived alleles at spkw1 and heterozygous for C57BL/6J and C3H/HeJ alleles at spkw2.

Mapping and Phenotype information for this QTL, its variants and associated markers

J:98638

Linkage analysis was performed on 53 animals from a (C3H/HeJ x C57BL/6J)F1 x C3H/HeJ backcross to identify QTLs associated with spike wave discharges (SWDs) in the cortex, thalamus, and hippocampus characteristic of absence seizures. Parental strain C3H/HeJ exhibits a high frequency of SWDs without associated brain abnormalities whereas parental strain C57BL/6J is SWD-negative. Over 120 SNPs at an average spacing of 20 markers were typed for the genome scan.

A significant locus accounting for over 40% of the SWD phenotypic variance mapped to centromeric mouse Chromosome 9. This locus is named spkw1 (spike wave 1) and the 95% confidence interval pans approximately 30 cM. C3H/HeJ-derived alleles at spkw1 confer increased SWD incidence and appear to have arecessive effect. Potential candidate genes mapping near spkw1 are Gria4 and Kcnj5. However, neither candidate gene exhibits sequence variation or differential expression between C3H/HeJ and C57BL/6J. The spkw1 locus is syntenic to a region of rat Chromosome 8 where suggestive association to absence seizures has been mapped.

Pairwise analysis revealed a modifying locus mouse Chromosome 8. This locus is named spkw2 (spike wave 2) and, together with spkw1, accounts for over 50% of the phenotypic variance in the backcross animals. C57BL/6J-derived alleles at spkw2 confer increased incidence of SWDs when in the presence of C3H/HeJ-derived spkw1 alleles.

References

• Original: J:98638 Frankel WN, et al., Development of a new genetic model for absence epilepsy: spike-wave seizures in C3H/He and backcross mice. J Neurosci. 2005 Mar 30;25(13):3452-8
• All: 1 reference(s)