Mapping Data

Experiment

• Experiment
  TEXT-QTL
• Chromosome
  2
• Reference
  J:70479 Turri MG, et al., Quantitative trait locus mapping in laboratory mice derived from a replicated selection experiment for open-field activity. Genetics. 2001 Jul;158(3):1217-26
• ID
  MGI:5760007

Genes

Gene	Assay Type
Axtldb2	visible phenotype

Notes

• Reference
  DeFries strains:
  QTL were mapped in two large F2 intercrosses from four lines derived from a replicated selection experiment for open-field activity, an animal model for susceptibility to anxiety. The foundation for the selection experiment consisted of an F3 generation derived from a cross between inbred lines, BALBc/J and C57BL/6J. Ten F3 litters that contained at least two males and females were chosen at random. The most active male and female within each litter were selected to become the progenitors of one selected line, termed H1. The least active male and female from each of the same ten litters were selected to serve as progenitors of a low activity line, L1. The same selection procedure was applied to members of a second randomly chosen group of 10 F3 litters as parents for replicate selected lines H2 and L2. The resulting progeny represented the first selected generation. Within the two high lines the most active male and female were selected from each litter, whereas the least active male and female were selected from each litter in the two low lines.Thirty generations of selection were completed and in generation 30 open field activity scores of the high lines were 30 times greater than those of the low lines.
  Following the suspension of selection the lines were randomly mated within line for 18 generations and then inbred using brother-sister mating.
• Experiment
  The initial cross was of 815 mice in the (H1 x L1) cross and of 821 mice in the (H2 x L2) cross. All of the animals were genotyped with all markers, a total of 128,500 genotypes. The results for mapping open field behaviors, behaviors in the the elevated plus maze and in the light-dark box in the two replicated crossed were obtained and compared in tables 1, 3 and 4. Haplotype information and the direction of effect of each QTL allele were used to confirm that the QTL mapped in the two crosses lie in the same chromosomal regions, but authors were unable to determine whether QTL in the two crosses represented the same genes.
  
  03.12.2016 Curator Note: We have assigned offical nomenclature to the significant QTL (LOD=3.2) identified in each cross, (H1 x L1) and (H2 x L2). We have also assigned offical nomenclature to the significant QTL identified when cross data was combined if a significant QTL was not also identified in either of the two independent crosses.
  
  In the (H1 x L1)F2 cross the following anxiety related QTL mapped to Chromosome 2:
  
  Axtldb2, anxiety-light dark box 2, seconds to enter light side, LOD=3.4 at 56 cM, accounting for 2.5% of trait variance, Table 3.