Phylogenetic analysis of the ATP-binding cassette proteins suggests a new ABC protein subfamily J in Aedes aegypti (Diptera: Culicidae)

BACKGROUND: We performed an in-depth analysis of the ABC gene family in Aedes aegypti (Diptera: Culicidae), which is an important vector species of arthropod-borne viral infections such as chikungunya, dengue, and Zika. Despite its importance, previous studies of the Arthropod ABC family have not focused on this species. Reports of insecticide resistance among pests and vectors indicate that some of these ATP-dependent efflux pumps are involved in compound traffic and multidrug resistance phenotypes. RESULTS: We identified 53 classic complete ABC proteins annotated in the A. aegypti genome. A phylogenetic analysis of Aedes aegypti ABC proteins was carried out to assign the novel proteins to the ABC subfamilies. We also determined 9 full-length sequences of DNA repair (MutS, RAD50) and structural maintenance of chromosome (SMC) proteins that contain the ABC signature. CONCLUSIONS: After inclusion of the putative ABC proteins into the evolutionary tree of the gene family, we classified A. aegypti ABC proteins into the established subfamilies (A to H), but the phylogenetic positioning of MutS, RAD50 and SMC proteins among ABC subfamilies—as well as the highly supported grouping of RAD50 and SMC—prompted us to name a new J subfamily of A. aegypti ABC proteins.