Selection in the heterodimerisation interface during the radiation of Mecopterida. Posterior probabilities for each site to belong to the site-class under positive selection (along branch A or branch B) or relaxed evolution (along branch C) were projected onto the crystal structure of the USP LBD domain of Drosophila (1HG4). Probabilities are distributed along a colour scale from yellow (p=0) to red (p=1). Sequences not available for the estimation of evolutionary rates are in white. The lipid ligand (LPP) is in green. (A) Branch A, stem lineage of Mecopterida. (B) Branch B, subdivision between Amphiesmenoptera (Lepidoptera, Trichoptera) and Antliophora (Diptera, Mecoptera, Siphonaptera). (C) Branch C, subdivision of Diptera into the suborders Brachycera and Nematocera. (D) The hydrophobic core (helix H10) is shown in blue, the insect canonical interaction surface is in purple and the Mecopterida specific surface is in cyan (for details, see Additional file 1: Table S1 of: .
Chaumot et al. BMC Evolutionary Biology 2012 12:199 doi:10.1186/1471-2148-12-199