Sex-biased gene expression in antennae of Drosophila suzukii

Authors: AHN, S-J - Oregon State University; OH, H-W - Korean Research Institute Of Bioscience And Biotechnology; Corcoran, Jacob; KIM, JI-AE - Korean Research Institute Of Bioscience And Biotechnology; PARK, K-C - New Zealand Institute Of Plant & Food Research; PARK, C - Gyeongsang National University; Choi, Man-Yeon

Submitted to: Archives of Insect Biochemistry and Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/11/2020
Publication Date: 1/28/2020
Citation: Ahn, S., Oh, H., Corcoran, J., Kim, J., Park, K., Park, C.G., Choi, M.Y. 2020. Sex-biased gene expression in antennae of Drosophila suzukii. Archives of Insect Biochemistry and Physiology. 104(1):e21660. https://doi.org/10.1002/arch.21660.
DOI: https://doi.org/10.1002/arch.21660

Interpretive Summary: Spotted wing drosophila (SWD), Drosophila suzukii, is an economically important pest of small fruits globally. The estimated economic impact is US$800 million annually in the U.S. alone, and continues to increase every year. Currently, the control methods rely on chemical pesticides despite human health, environmental risks and insecticide resistance. To replace or reduce the use of chemical insecticides, alternative management options are needed. Recent research has focused on finding unique physiological aspects of SWD, that could be good biological targets to develop alternatives to chemical control methods. This study determined differential gene expression between male and female antennae of SWD. We identified antennae-enriched genes in the male and female, and evaluated their expression levels. Molecular and bioinformatic approaches will be applied to identify specific plant volatiles and chemosensory genes of the fly. The molecular data presented in this report serves as a foundation for investigations into sex-biased olfactory functions in SWD, and to gain a better understanding of the insects mating, host plant-mediated behaviors, and ability to lay eggs. Our study also provides insight towards developing biologically-based pest control practices.

Technical Abstract: Spotted wing drosophila (Drosophila suzukii ) differs from other members of the genus Drosophila in terms of its host preference and oviposition behavior. Unlike other drosophilids, flies are attracted to ripening fruits, and females have a serrated ovipositor enabling eggs to be laid inside the fruit. In addition to having a large economic impact, its unique chemical-ecological characteristics have garnered considerable research interest. In this study we analyzed the D. suzukii antennal transcriptome to identify sex-biased genes by comprehensive analyses of differential gene expression levels, and to identify chemosensory genes highly expressed in male antennae (MA) or female antennae (FA). Among a total of 13,583 genes annotated in the fly genome, we determined that 11,787 genes (86.8%) were expressed in either MA or FA. However, only 132 genes (9 in MA, 7 in FA and 116 in both) with FPKM>1 were expressed exclusively in antennae, but 2,570 genes (9 in MA, 0 in FA and 2,561 in both) were enriched in antennae compared to the fly body. We determined that there were 185 and 113 sex-biased antennal genes in males and females, respectively. Interestingly, many immune-related genes were highly expressed in MA, whereas several chemosensory genes were at high rank in FA. In addition, differential gene expression was analyzed in 10 different chemosensory gene families, through which we identified several sex-biased chemosensory genes encoding odorant receptors, odorant-binding proteins, chemosensory proteins, ionotropic receptors and cytochrome P450s. These results suggest that the highly expressed sex-biased chemosensory and non-chemosensory genes in antennae are likely involved with mating, host-finding, or other sex-specific functions. The molecular results presented here will facilitate future studies on the unique chemoreception of D. suzukii, as well as on the development of new management strategies for this pest species.