Mapping Data

Experiment

• Experiment
  TEXT-QTL
• Chromosome
  4
• Reference
  J:148559 Blizard DA, et al., Blood pressure and heart rate QTL in mice of the B6/D2 lineage: sex differences and environmental influences. Physiol Genomics. 2009 Feb 2;36(3):158-66
• ID
  MGI:5755867

Genes

Gene	Assay Type
Bpq10	resistance/susceptibility
D4Mit104

Notes

• Experiment
  The genetic variation underlying varaition in systolic blood pressure and heart rate were analyzed in a QTL study using 395 (C57BL/6J x DBA/2J)F2 mice (197 males, 198 females) and 22 BXD recombinant inbred (RI) strains.
  
  Systolic blood pressure and heart rate were measured in F2 animals on seven separate occasions, four consecutive daily tests at 115 days, another test 1 week later, then twice more at four week intervals. RI mice were measured on five occasions, four consecutive daily tests and once the following week. Test groups consisted of 12-16 animals equally divided by sex.
  
  F2 mice were genotyped with 96 microsatellite markers spaced at approximately 15 to 20 cM intervals throughout the genome. Interval mapping analysis and a genome wide scan for epistatic interactions between all pairs of autosomal markers in the intercross was carried out using J/qtl and R/qtl packages.Thresholds were obtained for an F2 intercoss via 10,000 simualtions by the developes of R/qtl. Sex, suggestive, or significant QTL and epistatic interactions were included in a multiple regression model for each trait.
  
  A significant QTL influencing systolic blood pressure, Bpq10, was identified mapping on Chromosome 4, peaking at 9.9 cM nearest marker D4Mit104 with a LOD=5.8. Bpq10 accounted for 4.7% of rait variance; the confidence interval ranged from 0 to 37 cM. The C57BL/6J allele at this locus was associated with increased blood pressure with the effects of B6 homozygosity at this locus significantly greater than heterozygous or homozygous for the decreasing allele. [Table 2].
  
  Extensive SNP analysis was applied at the Bpq10 locus. 33 SNPs were found in 20 genes in the region (Supplemental Fig S1).
  
  A suggestive QTL for heart rate was also identified on Chr4, peaking at 1.9 cM with a confidence interval between 0-12 cM. Peak LOD=3.2, the C57BL/6J allele at this locus was associated with increased heart rate. [Table 2].