Identification and Confirmation of Quantitative Trait Loci Regulating Alcohol Consumption in Congenic Strains of Mice (original) (raw)

Background C57BL/6 inbred mice prefer alcohol whereas DBN2 mice avoid it. We describe the construction of congenic strains of mice in which DBN2 alleles for alcohol avoidance were placed on a C57BW6 background using phenotypic selection. Methods: Mice were primed to drink 10% v/v ethanol in water for 2 days before a two-bottle choice paradigm. N, males who demonstrated an alcohol-avoidance phenotype were backcrossed to B6 females to construct 15 independent lines. Results: Eight of these lines were lost due to failure to breed or absence of males with an alcohol-avoidance phenotype. The remaining sublines were split to form a total of 21 sublines. In the N, and N9 generations, a genome scan located provisional quantitative trait loci (QTLs) on chromosomes 1,2,3,6, and 9. Progeny testing confirmed QTLs on chromosomes 1 and 2. Conclusions: The QTL on chromosome 2 overlaps the 95% confidence interval of Alcpl whereas that on chromosome 1 is new and has been called Alcp5. Marker-assisted selection was used in the N, and subsequent generations to maintain the congenic lines and produce congenic strains.