Comparative Genomics Provide Insights Into Function and Evolution of Odorant Binding Proteins in .

Insect olfaction is vital for foraging, mating, host-seeking, and avoidance of predators/pathogens. In insects, odorant binding proteins (OBPs) are involved in transporting hydrophobic odor molecules from the external environment to receptor neurons. The codling moth, , one of the most destructive insect fruit pests, causes enormous economic losses. However, little is known about the number, variety, gains and losses, and evolution of genes in . Here we report the identification of 40 in , most (75%) of which are classic , using genomic and transcriptomic analyses. Two genes were lost in relative to possible distant ancestor in Lepidoptera lineage based on an analysis of gene gains and losses. The phylogenetic tree and chromosome location showed that the expansion of genes mainly resulted from tandem duplications, as the gene was duplicated twice along with loss of . Two positive selection sites of the gene were identified while other genes evolved under purifying selection. Our results provide fundamental knowledge of genes allowing further study of their function in .