Three generations of breeding were sufficient for significant segregation of the high and low preference lines; preference in the high line was approximately 10 times greater than in the low line. Genotyping the lines not only confirmed the segregation of the lines but also illustrated that considerable genetic diversity was retained (Fig. 2). The genotype data also showed that from a genetic perspective, the high line was closest to the WSB founder strain. These data were of interest in that it has been reported that in both the HS-CC and the related DO mice there is a WSB-dominant meiotic drive locus on chromosome 2 (Chesler et al. 2016); numerous preference QTL have been detected on chromosome 2, albeit in less genetically diverse populations (Belknap & Atkins 2001). Using a selective breeding protocol, the meiotic drive locus and the associated WSB alleles have been eliminated from the DO population (Chesler et al. 2016). We have compared these DO mice with the HS-CC; no difference was detected in either acute or chronic preference consumption (data not shown). For both the HS-CC and the ‘new’ DO, approximately 25% of the animals consume daily >10 g/kg of ethanol.
