Fig. 3

CDC bottle assays were used to detect the function of miR-4448 by oral feeding of the miR-4448 mimic in DR strain mosquitoes. Oral feeding with the miR-4448 mimic could reduce mosquito resistance to deltamethrin. a, b Oral feeding of the miR-4448 mimic upregulated the expression of miR-4448 (by 1.97-fold) and downregulated the expression of CYP4H31 (47.85%) in DR strain. c Mosquito mortality was assessed after incubation for a 2 h in a CDC bottle containing 7 mg/l deltamethrin. The mortality of the miR-4448 mimic group was higher than that of the acetone control, WT, and miRNA control mimic (NC1) groups. At 90 and 105 min, the mortality rates of miR-4448 mimic-fed mosquitoes were 52.5% (21/40) and 65.0% (26/40), respectively, which were higher than those of the NC1 group (42.4% [14/33] and 51.5% [17/33]). Data are representative of three technical replicates of three biological replicates and are indicated as the mean ± SE; ***P < 0.001, *P < 0.05. RE relative expression, DR-strain deltamethrin-resistant strain