title: Mapping a mouse limbic seizure susceptibility locus on chromosome 10.
abstract: OBJECTIVE
  Mapping seizure susceptibility loci in mice provides a framework for identifying potentially novel candidate genes for human epilepsy. Using C57BL/6J × A/J chromosome substitution strains (CSS), we previously identified a locus on mouse chromosome 10 (Ch10) conferring susceptibility to pilocarpine, a muscarinic cholinergic agonist that models human temporal lobe epilepsy by inducing initial limbic seizures and status epilepticus (status), followed by hippocampal cell loss and delayed-onset chronic spontaneous limbic seizures. Herein we report further genetic mapping of pilocarpine quantitative trait loci (QTLs) on Ch10.
  
  
  METHODS
  Seventy-nine Ch10 F(2) mice were used to map QTLs for duration of partial status epilepticus and the highest stage reached in response to pilocarpine. Based on those results we created interval-specific congenic lines to confirm and extend the results, using sequential rounds of breeding selectively by genotype to isolate segments of A/J Ch10 genome on a B6 background.
  
  
  RESULTS
  Analysis of Ch10 F(2) genotypes and seizure susceptibility phenotypes identified significant, overlapping QTLs for duration of partial status and severity of pilocarpine-induced seizures on distal Ch10. Interval-specific Ch10 congenics containing the susceptibility locus on distal Ch10 also demonstrated susceptibility to pilocarpine-induced seizures, confirming results from the F(2) mapping population and strongly supporting the presence of a QTL between rs13480781 (117.6 Mb) and rs13480832 (127.7 Mb).
  
  
  CONCLUSIONS
  QTL mapping can identify loci that make a quantitative contribution to a trait, and eventually identify the causative DNA-sequence polymorphisms. We have mapped a locus on mouse Ch10 for pilocarpine-induced limbic seizures. Novel candidate genes identified in mice can be investigated in functional studies and tested for their role in human epilepsy.
authors: Department of Neurology, Columbia University, New York, New York 10032, USA. mw211@columbia.edu
authors: Melodie R
authors: MR
authors: Winawer
authors: Sandra S
authors: SS
authors: Gildersleeve
authors: Austin G
authors: AG
authors: Phillips
authors: Daniel
authors: D
authors: Rabinowitz
authors: Abraham A
authors: AA
authors: Palmer
mesh_terms: D000818:Animals; D002874:Chromosome Mapping; D003292:Convulsants / Q000494:pharmacology; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D005838:Genotype; D008032:Limbic System / Q000187:drug effects / Q000502:physiology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL / Q000235:genetics; D010862:Pilocarpine / Q000494:pharmacology; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D040641:Quantitative Trait Loci; D012640:Seizures / Q000139:chemically induced / Q000235:genetics*; D013226:Status Epilepticus / Q000139:chemically induced
chemical_list: D003292:Convulsants; D010862:Pilocarpine