Genes on mouse Chromosomes 2 and 9 determine variation in ethanol consumption

Quantitative trait locus (QTL) mapping efforts in alcohol (ethanol) researc h are beginning to generate promising data that may ultimately lead to the identification of genes influencing alcohol addiction. Rodents have been ex tensively utilized to study ethanol's rewarding and aversive effects, and t o demonstrate the existence of genetic influences on traits such as free-ch oice ethanol-consumption, ethanol-conditioned place preference and ethanol- conditioned taste aversion. The purpose of the current investigation was to verify or eliminate from further consideration putative QTLs for free-choi ce ethanol consumption originally identified in BXD Recombinant Inbred (RI) strains and other informative genetic crosses. B6D2F(2) mice were utilized in a verification testing strategy to evaluate the viability of putative e thanol consumption QTLs. When data were combined from BXD RI, B6D2F(2) and short-term selected line (STSL) mapping studies, verification was obtained for two QTLs, one on Chromosome (Chr) 9 (proximal-mid) and another on Chr 2 (distal), and suggestive verification was obtained for QTLs on Chrs 2 (pro ximal), 3, 4, 7, and 15. In addition, the possible generic association of e thanol consumption with conditioned place preference was evaluated. Genetic correlations were estimated from BXD RT strain means, and QTL maps for the se traits were compared to evaluate the possibility of a genetic associatio n. The correlational analysis yielded a trend (r = 0.34, p = 0.09), but no statistically significant results. However, comparisons of QTL mapping resu lts between phenotypes suggested some possible genetic overlap for these tr aits, both putative measures of ethanol reward. These data suggest that the determinants of these two measures are genetically diverse, but may share some common genetic elements.