Genome-wide analyses of ATP-Binding Cassette (ABC) transporter gene family and its expression profile related to deltamethrin tolerance in non-biting midge Propsilocerus akamusi.

Non-biting midges are dominant species in aquatic systems and often used for studying the toxicological researches of insecticides. ATP-binding cassette (ABC) transporters represent the largest known members in detoxification genes but is little known about their function in non-biting midges. Here, we selected Propsilocerus akamusi, widespread in urban streams, to first uncover the gene structure, location, characteristics, and phylogenetics of chironomid ABC transporters at genome-scale. Fifty-seven ABC transporter genes are located on four chromosomes, including eight subfamilies (ABCA-H). The ABCC, ABCG, and ABCH subfamilies experienced the duplication events to different degrees. The study showed that expression of the PaABCG17 gene is uniquely significantly elevated, with deltamethrin concentration increasing (1, 4, and 20 ug/L) both in RNA-seq and qPCR results. Additionally, the ABC transporter members of other six chironomids with assembled genomes are first described and used to investigate the characteristic of those living in the different adverse habitats. The ABC transporter frame for Propsilocerus akamusi and its transcriptomic results lay an important foundation for providing valuable resources for understanding the ABC transporter function in insecticide toxification of this species as well as those of other non-biting midges. The PaABCG17 gene is shown to play an important role in deltamethrin detoxification, and it functions need to be further investigated and might be used in the management of insecticide-resistance in chironomid adults.