In each of the three brain regions, the DW genes unique to that region were highly enriched in synapse-associated genes. This effect was particularly dramatic in the CeA where a large number of both GABA and glutamate receptor subunits were affected. DW genes were distributed across several network modules, making the distribution of the DW genes more diffuse than that for the DV genes. It was also observed in both the CeA and SH that a number of network modules were largely preserved from the effects of selection on wiring. Many of these preserved modules had annotations associated with ATP metabolic processes, DNA replication, rRNA cellular respiration and so on. One purpose of using a short-term selective breeding protocol is to minimize genetic drift and focus the analysis on only those alleles associated with the phenotype of interest, here ethanol preference. Clearly, the DW data illustrates that even three rounds of selection had marked and extensive effects on the brain transcriptome.
