Figure 5. OR coexpression is driven by both receptor duplication and receptor co-option.

Plots show the genomic and phylogenetic distance for pairs of ligand-specific IRs (A) or ORs (B). Color indicates whether the receptors are coexpressed in the same OSN subtype. Coexpressed ORs are further divided into cases where both receptors are found only in the same, single subtype (green) or at least one receptor is also found in additional subtypes (pink). Marginal densities for phylogenetic distance shown at right of each scatterplot. Phylogenetic distance in units of amino acid changes/site.