Hrq4^DBA/2J
QTL Variant Detail

Summary

• QTL variant: Hrq4^DBA/2J
• Name: heart rate QTL 4; DBA/2J
• MGI ID: MGI:5756037
• QTL: Hrq4 Location: unknown Genetic Position: Chr1, Syntenic

Variant origin

• Strain of Specimen: DBA/2J

Variant description

• Allele Type: QTL

Notes

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

J:148559

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, female specific QTL influencing heart rate, Hrq4, was identified on Chr 1 peaking at 72 cM near marker D1Mit87 with a LOD=7.9. The 95% confidence interval spanned 48-86 cM. The locus accounted for 8.5% of trait variance and the C57BL/6J allele was associated with increased heart rate. SNP analysis revealed one SNP in the Chrng gene that was predicted to be possibly damaging.

Another significant locus, Hrq5, mapped to Chr 5 peaking at 54 cM nearest marker D5Mit10 with a LOD=8.5. The 95% confidence interval spanned 45-64 cM. Hrq5 accounted for 9.6% of trait variance and the DBA/2J allele was associated with increased heart rate.

A suggestive QTL for heart rate, Hrq6, mapped to Chr 11 peaking at 2.0 cM nearest marker D11Mit227 with a LOD=3.1. The 95% confidence interval spanned from 0-24 cM. Hrq6 accounted for 2.7% of trait varaince and the C57BL/6J allele was associated with increased heart rate.

References

• Original: 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
• All: 1 reference(s)