Thirty-six splicing hub nodes were significantly (FDR < 0.05) affected by selection. In contrast, 253 coexpression hub nodes were affected by selection (FDR < 0.05). The difference may reflect a greater stability of the splicing nodes and/or insufficient read depth to detect changes in the splicing network. Eighteen of these splicing hub nodes lie with known preference QTL intervals. However, the relevance of this observation will depend on which genes exhibit cis-regulated AEU. Of the remaining affected hub nodes, there is some gene expression evidence directly or indirectly linking eight of the hubs to ethanol phenotypes (Table S9); however, only one of these studies focused on preference risk. Carr et al. (2007) used inbred preferring and non-preferring rats to form congenic strains to determine what genes are DE in a Chr 4 QTL. Son of sevenless 1 (Sos1), a GTPase-activating protein, was found to show modestly higher expression in the preferring animals. However, this was not confirmed with quantitative reverse transcriptase-polymerase chain reaction.
