Mapping Data

Experiment

• Experiment
  TEXT-QTL
• Chromosome
  7
• Reference
  J:190489 Smolock EM, et al., Genetic locus on mouse chromosome 7 controls elevated heart rate. Physiol Genomics. 2012 Jul 3;44(13):689-98
• ID
  MGI:5804640

Genes

Gene	Assay Type
Hrq8	visible phenotype
Hrq9	visible phenotype

Notes

• Experiment
  In a previous study, the authors reported that heart rate (HR) was approximately 80 beats/min higher in SJL/J compared with C3HeB/FeJ mice, with no difference in systolic blood pressure (SBP). In the current study, linkage analysis was performed on a mapping population of 134 (C3HeB/FeJ x SJL/J) backcross mice to identify QTL related to HR and SBP as measured by tail-cuff plethysmography. The authors used 80 microsatellite markers to perform genetic linkage mapping analysis. They identified one QTL reaching genome-wide significance:
  
  QTL Hrq8 (Heart rate QTL 8) maps to Chromosome 7 with a peak LOD score of 6.7 at 41 cM. HR was greater in N2 progeny homozygous for the SJL/J allele compared with the C3HeB/FeJ allele at the markers D7Mit69.1 and D7Mit350.1.
  
  The authors also performed a GWAS mapping study using 322 mice from the Hybrid Mouse Diversity Panel (HMDP; 58 strains, n = 56/strain). The HMDP contains 4 million informative SNP markers and helped the authors to identify one genomic locus reaching genome-wide significance:
  
  QTL Hrq9 (Heart rate QTL 9) maps to Chromosome 7 with a peak located at 64.9 Mb (64.2 - 65.1). The peak association was observed for 17 SNPs that are localized within three GABA(A) receptor genes - Gabrb3, Gabra5, and Gabrg3 - encoding receptor subunits for the inhibitory neurotransmitter GABA(A). Although it co-localizes with the Hrq8 locus, no alleles were described for Hrq9.