Fig. 5

Phylogenetic tree of the odorant binding protein (OBP) family. The protein sequences included were from Dendroctonus ponderosae (Dpon, red), Agrilus planipennis (Apla, blue), Anoplophora glabripennis (Agla, green), and Tribolium castaneum (Tcas, orange). The tree is based on a MAFFT alignment, constructed using FastTree, and unrooted. Numbers at nodes are local support values, calculated using the Shimodaira-Hasegawa (SH) test implemented in FastTree. For clarity, exact SH values are only shown for major branches and if > 0.7, whereas SH values for all branches are indicated by the colored circles; support increases with the size and brightness of the circles. The putatively alternatively spliced DponOBP6a/b and DponOBP7a/b are each represented by one splice variant. The OBP “tetramer” DponOBP4 was analyzed separately (Additional file 3). Thick red arcs indicate the clades of Minus-C OBPs, Plus-C OBPs, and the antennal binding protein II (ABPII). Thin black arcs indicate clades of classic OBPs, which include one member from each of the four species in the analysis. Asterisks indicate two Minus-C OBPs from D. ponderosae, which in this analysis fell outside the Minus-C clade