Mapping of quantitative trait loci for ethanol preference in quasi-congenic strains

Ethanol preference, a component of alcoholism, has been known for four deca des to differ greatly between C57BL/6 and BALB/c inbred mouse strains. For mapping quantitative trait loci (QTLs) that affect ethanol preference, we u sed a set of B6.C Recombinant QTL Introgression (RQI) strains, which carry about 5% of the donor BALB/cJ (C) genome on a C57BL/6ByJ (B6) background. A fter characterizing males of the progenitor and RQI strains for variations in ethanol preference, we scanned their genome for polymorphisms at 244 din ucleotide-repeat marker loci known to differ between B6 and C. Because of t he introgression of BALB/c-type QTLs onto the B6 background, some strains s howed ethanol preference significantly lower or higher than that of the bac kground strain, suggesting that genetic interaction between ethanol prefere nce QTLs and the background can be operative. The genomic region showing th e strongest influence on ethanol preference was on mouse chromosome 15, and corresponds to human chr.12 q11-q13. (C) 2000 Elsevier Science Inc. All ri ghts reserved.