1 Vol.:(0123456789) Scientific RepoRtS | (2020) 10:14394 | https://doi.org/10.1038/s41598-020-71250-0 www.nature.com/scientificreports post‑transcriptional modulation of cytochrome P450s, Cyp6g1 and Cyp6g2, by miR‑310s cluster is associated with DDt‑resistant Drosophila melanogaster strain 91‑R Keon Mook Seong 1* , Brad S. Coates 2 & Barry R. Pittendrigh 3 The role of miRNAs in mediating insecticide resistance remains largely unknown, even for the model species Drosophila melanogaster. Building on prior research, this study used microinjection of synthetic miR‑310s mimics into DDt‑resistant 91‑R fies and observed both a signifcant transcriptional repression of computationally-predicted endogenous target P450 detoxifcation genes, Cyp6g1 and Cyp6g2, and also a concomitant increase in DDT susceptibility. Additionally, co-transfection of D. melanogaster S2 cells with dual luciferase reporter constructs validated predictions that miR‑310s bind to target binding sites in the 3ʹ untranslated regions (3ʹ‑UtR) of both Cyp6g1 and Cyp6g2 in vitro. Findings in the current study provide empirical evidence for a link between reduced miRNA expression and an insecticidal resistance phenotype through reduced targeted post‑transcriptional suppression of transcripts encoding proteins involved in xenobiotic detoxifcation. These insights are important for understanding the breadth of adaptive molecular changes that have contributed to the evolution of DDt resistance in D. melanogaster. Te exposure of a species to changing environmental conditions, such as variation in nutrient availability, climate, and toxic chemicals, can lead to corresponding phenotypic change(s) via adaptive directional selec- tion. Insecticidal compounds—including synthetic chemicals, natural products, and protein toxins—represent human-imposed selection pressures upon insect populations. Specifcally, insecticides have been widely used to suppress insect populations in eforts to protect human health by stabilizing the output of agricultural com- modities and foodstufs 1 , and reducing the incidence of insect vector-borne diseases, such as malaria and dengue fever 2,3 . However, frequent and widespread application of insecticides has contributed to the development of insect populations with high frequencies of phenotypic resistance to one or more classes of insecticides 4 . Such responses by insect populations and selection for high levels of resistance represent serious threats to many pest control programs. Te evolution of insecticide resistance in insect populations involves genomic variations in the genome that, in turn, ofers the scientifc community an opportunity to both understand the genes directly involved in resistance and, in some cases, regulatory mechanisms associated with those genes. A model system that afords the opportunity to perform gene-by-gene analysis of traits involved in polygenic pesticide resistance is that of dichlorodiphenyltrichloroethane (DDT) resistance in Drosophila melanogaster (hereafer referred to as Drosophila). DDT is an organochlorine insecticide that disrupts the insect nervous system by afecting the permeability of nerve cell plasma membranes and causing paralysis 5 . While DDT was extensively used during the post- World War II to control insect pests, deleterious side efects on non-target mammalian, bird, and insect species open 1 Department of Applied Biology, College of Ecology and Environment, Kyungpook National University, Sangju, Korea. 2 USDA-ARS, Corn Insects and Crop Genetics Research Unit, Ames, IA, USA. 3 Department of Entomology, Michigan State University, East Lansing, MI, USA. * email: kseong6@knu.ac.kr