Alignment of the transcriptome with individual variation in animals selectively bred for High Drinking-In-the-Dark (HDID)

•There are considerable individual differences seen in the amount of ethanol consumed in High Drinking in the Dark mice.•This variation is most likely associated with epigenetic factors.•Sizable overlap exists between genes associated with individual variation and risk for excessive ethanol consumption.•Many of these genes are related to NMDA-mediated synaptic plasticity.

Among animals at risk for excessive ethanol consumption such as the HDID selected mouse lines, there is considerable individual variation in the amount of ethanol consumed and the associated blood ethanol concentrations (BECs). For the HDID lines, this variation occurs even though the residual genetic variation associated with the DID phenotype has been largely exhausted and thus is most likely associated with epigenetic factors. Here we focus on the question of whether the genes associated with individual variation in HDID-1 mice are different from those associated with selection (risk) (Iancu et al., 2013). Thirty-three HDID-1 mice were phenotyped for their BECs at the end of a standard DID trial, were sacrificed 3 weeks later, and RNA-Seq was used to analyze the striatal transcriptome. The data obtained illustrate that there is considerable overlap of the risk and variation gene sets, both focused on the fine-tuning of synaptic plasticity.