Mapping Data

Experiment

• Experiment
  TEXT-QTL
• Chromosome
  6
• Reference
  J:101833 Nelson TM, et al., Haplotypes at the Tas2r locus on distal chromosome 6 vary with quinine taste sensitivity in inbred mice. BMC Genet. 2005 Jun 6;6(1):32
• ID
  MGI:3606254

Genes

Gene	Assay Type
Btts	visible phenotype
D6Mit13	PCR
D6Mit254	PCR
D6Mit374a	PCR

Notes

• Experiment
  Linkage to bitterness tasting was performed using 17 BXD (B=C57BL/6J; D=DBA/2J) recombinant inbred (RI) strains and a panel of 762 informative markers. Animals were subjected to a quick lick test with 1 mM and 3 mM quinine hydrochloride (QHCl) solution, and denatonium benzoate (DB) solution. Parental strain DBA/2J exhibits decreased aversion to QHCL at both concentrations compared to parental strain C57BL/6J. Aversion to DB did not differ between C57BL/6J and DBA/2J.
  
  Sensitivity to 1 mM QHCl showed significant linkage to a single marker on distal mouse Chromosome 6 at 63.3 cM (D6Mit13a, LRS=20.5). This locus is named Btts (bitterness tasting). A conservative estimation of the Btts QTL interval is 5 Mb between markers D6Mit254 (60.55 cM) and D6Mit374a (74 cM). Btts also shows suggestive linkage to 3 mM QHCl sensitivity. C57BL/6J-derived alleles at Btts confer increased sensitivity to QHCl. There are 24 Tas2r (taste receptor, type 2) genes clustered within 1.2 Mb on either side of D6Mit13a. The authors hypothesize that one or more of these Tas2r genes are responsible for the Btts phenotype. A previously identified quinine tasting QTL named Qui (50.5 cM) maps near Btts.
  
  Analysis of the Tas2r candidate gene cluster revealed 307 coding region polymorphisms between C57BL/6J and DBA/2J, half of which are silent mutations. All 24 Tas2r genes have different alleles between C57BL/6J and DBA/2J, and the entire locus appears as a single haplotype.
  
  Suggestive linkage to 1 mM QHCl tasting mapped to mouse Chromosome8 (LRS=11.4).