For the DV genes (Table S5), higher variability was observed in the high line (208 genes with higher variability in the high line vs. 15 genes with higher variability in the low line). Annotation of the DV genes (Eden et al. 2009) showed significant enrichment in genes associated with cell–cell signaling and included the GO categories ‘Response to Endogenous Stimulus’ and ‘Signaling Receptor Activity’ (Table S5). The 19 genes in the latter category included Adra1a, Chrna7, Fzd3, Gabrb2, Grin2a, Grin2b, Htr2a, Kit, Oprd1 and Sort1. Fdz3, Kit and Sort1 were detected as DE by Mulligan et al. (2006). Coexpression network information was used to further annotate the DV genes. The DV genes exhibited significant enrichment in two coexpression modules: greenyellow (P < 10−42) and pink (P < 7 × 10−3) (Table S5). The GO annotation of these modules is found in Table S3. The greenyellow module was notably enriched in annotations associated with neurons, e.g. neuronal cell body (P < 1 × 10−5) and signaling receptor activity (P < 5 × 10−6). The pink module was enriched in annotation associated with glutamate secretion (P < 5 × 10−4).
