Figure 1.
A quantitative trait locus (QTL) on mouse chromosome 10 has a major effect on MA drinking in MADR mice. The QTL on proximal chromosome 10 (10–40 Mb) explains greater than 50% of the genetic variance in the MA drinking phenotype (Belknap et al, 2013). Data are presented as directional genome-wide logarithm of the odds (LOD) scores. Positive and negative LOD scores indicate that higher trait scores are conferred by the D2 and B6 alleles, respectively. Dashed horizontal lines indicate statistically significant support for a QTL at p<2 × 10−5. Although there are a large number of genes in this interval that have the potential to influence the MA drinking trait, of particular interest based on the literature supporting involvement of opioid, glutamate, and TAAR1 in MA responses, are the mu opioid receptor gene (Oprm1), metabotropic glutamate receptor gene (mGlur1), and Taar1, which reside at 6.76, 10.7, and 23.9 Mb, respectively. Data shown were generated using two independent sets of replicated MADR lines, produced 2 years apart. Also shown are combined data for the independent replications of the QTL study. Figure adapted from Belknap et al (2013), with permission.