Genomic context for venom gene regulation and production. (A) Pie chart of the venom proteome with relative abundance of venom families (redrawn from Saviola et al. 2015). Chromosomal location of venom gene families (right); colored labels correspond to families from the proteome chart. (B) Gene expression across tissues of transcription factors (TFs) significantly up-regulated in the venom gland. (C) Heat maps of gene expression across tissues for venom genes in each of the three focal venom gene families and the genes immediately flanking (i.e., outside of) each venom cluster (labeled in gray). Vertical lines above each gene represent their promoters, with predicted NFI binding sites shown in red. Predicted GRHL1 binding sites in venom clusters are shown as turquoise squares. (D) Hi-C heat maps showing contact domains (black dashed boxes), for the SVMP, SVSP, and PLA2 venom genes (solid black boxes). Blue squares are predicted CTCF binding sites. Values to the left of heat maps are start and end coordinates (in Mb) of each region, visualized at 5-kb resolution.
