Structural and functional insights into the Diabrotica virgifera virgifera ATP-binding cassette transporter gene family

Abstract

Background The western corn rootworm, Diabrotica virgifera virgifera, is a pervasive pest of cultivated maize in North America and Europe, which has adapted to survive exposure to multiple insecticidal agents. Due to their role in insecticide transport, we sought to identify members of the ATP-binding cassette (ABC) transporter family in D. v. virgifera using a transcriptomics approach. Results In this study, 65 putative D. v. virgifera ABC (DvvABC) transporters were identified within a combined transcriptome assembly generated from embryo, larval, adult male, and adult female RNA-sequence libraries. Phylogenetic analysis placed the deduced amino-acid sequences of the DvvABC transporters into eight subfamilies (A to H). Of these, eight shared structural and functional conservation with Tribolium castaneum ABC transporter orthologs known to exhibit overt RNA interference (RNAi) knockdown phenotypes. Interestingly, depletion of DvvABCB_19147 and DvvABCG_3712 transcripts in adult females produced detrimental reproductive and developmental phenotypes (egg-laying or -hatching defects), demonstrating the potential of these genes as targets for RNAi-mediated insect control tactics. Conclusions By combining sequence data from four libraries covering three distinct life stages, we have produced a relatively comprehensive de novo transcriptome assembly for D. v. virgifera. Moreover, we have identified 65 members of the ABC transporter family, and provided the first insights into the developmental and physiological roles of ABC transporters in this pest species.