Because Lightweight mice have altered acute responses to ethanol, other ethanol-related behaviors were investigated on a B6 background. First, ethanol preference and consumption was examined using a two bottle choice paradigm in which individually-housed animals were given access to water or increasing concentrations of ethanol (from 3% to 20%) ad libitum. Relative to +/+ mice, Lwt/+ animals exhibited a higher preference for ethanol [F1,76(genotype) = 9.9, P = 0.004; F3,76(genotype×concentration) = 6.6, P<0.001] and consumed more ethanol [F1,76(genotype) = 14.5, P<0.00; F3,76 (genotype × concentration) = 6.9, P<0.001]. Increased preference and consumption was particularly pronounced at the higher concentrations tested (Figure 7A and 7C). It should be noted that no ethanol preference QTLs between the B6 and D2 strains have been mapped to distal chromosome 12. This was confirmed when we determined that no differences were observed between Control/+ mice relative to +/+ mice in preference for ethanol [F1,112(genotype) = 0.35, P = 0.56] or consumption of ethanol [F1,112(genotype) = 0.40, P = 0.53] (Figure 7B and 7D). Further, there were no alterations in taste sensitivity in Lwt/+ mice relative
