Phylogenomic partitioning of olfactory receptor genes. (A) Bayesian phylogeny of functional mammalian olfactory receptor (OR) genes available in Ensembl v52. OR gene family names are labeled on the termini of each subtree. MCMC posterior probabilities are given for each node. Polyphyletic families are clustered in subsequent analyses. (B) Ratio of functional OR genes per family (number of functional genes per family/total number of functional genes per species). The two C. familiaris (dog) genome assemblies are not significantly different (χ2 = 4.8, degrees of freedom [df] = 10, P ≈ 0.91). (C) Ratio of OR pseudogenes per family (number of pseudogenes per family/total number of pseudogenes per species). The two C. familiaris genome assemblies, boxer (7.6×) and poodle (1.5×), are significantly different (χ2 = 79.0, df = 8, P < 0.0001). (D) Heatmap displaying the relative percentage of functional genes in each OR gene family of different mammalian genomes, mapped onto the consensus phylogenetic tree for mammals. Selected ancestral reconstructions are shown at the bottom.
