The RNA-Seq data were analyzed at both the gene and exon level. Both analysis strategies confirmed earlier findings that the number of genes associated with ethanol preference is large and that these genes involve multiple functional pathways. However, the data differ from previous results (Mulligan et al. 2006) in that only a small number of genes (N = 7) were significantly DE (FDR < 0.05). We recognize that the sample sizes used in the current study were moderate (N = 24/line) and thus the power to detect significant changes was limited. Nonetheless, the data suggest that at least from the perspective of the NAc shell, numerous and large changes in gene expression are not necessary for selection.
