Figure 4.

Phylogeny comparing gustatory receptors (GRs) of Rhyzopertha dominica (red) to those of Anoplophora glabripennis (blue), Tribolium castaneum (yellow), and Agrilus planipennis (orange), rooted with the conserved lineage of sugar-sensitive receptors. Colored circles at nodes represent Shimodaira–Hasegawa support values, shaded from black (0–0.5) to white (1.0). Black arcs describe the known monophyletic subfamilies of coleopteran GRs, and remaining unlabeled GRs are assumed to be bitter sensitive. Three large lineage-specific radiations of GRs have been collapsed for clarity; identities of the removed genes are listed next to the collapsed sector. An asterisk denotes RdomGR14, which is likely to be a divergent member of the fructose GRs (see text).