Annotation and evolutionary analysis of chemosensory gene sequence data in the Colorado potato beetle, Leptinotarsa decemlineata

Plants and plant-feeding insects comprise the majority of global species diversity, and their coevolutionary dynamics provide an important window into the mechanisms that mediate niche evolution. In particular, there is considerable interest in understanding the nature of genetic changes that allow host-plant shifts to occur and to determine whether functional genomic diversity varies predictably in relation to host-plant breadth. Insect chemosensory proteins play a central role in mediating insect-plant interactions, as they directly influence plant detection and sensory stimuli during feeding. This large group of gene families is known to evolve rapidly, yet it remains unclear how these genes evolve in response to host-shifts and host specialization. Here we investigate whether selection at chemosensory genes is linked to host-plant expansion in the Colorado potato beetle (CPB), Leptinotarsa decemlineata (Coleoptera: Chrysomelidae), and whether rates of selection vary among ten closel...