RNA interference of Argonaute-1 disrupts ovarian development and enhances insecticide susceptibility in Tribolium castaneum.

BACKGROUND

With the development of rapid resistance, new modes of action for pesticides are needed for insect control, such as RNA interference (RNAi)-based biopesticides targeting essential genes. To explore the function of Argonaute-1 (Ago-1) and potential microRNAs (miRNAs) in ovarian development and their impact on rapid resistance in important storage pest Tribolium castaneum, we knocked down Ago-1 and observed the development of ovarian and insecticide susceptibility.

RESULTS

Our results indicated that Ago-1 had a relatively high transcriptional level of adult female T. castaneum during the sexual maturation period. RNAi experiment showed that Ago-1 knockdown significantly decreased the expression levels of ovarian development-related genes and disrupted ovarian development and the morphology was atrophied. Reproductive experiments showed that the egg laying rate of female beetles was close to zero, while the fertility of male beetles was not affected. The lipid droplet of the beetles in dsAgo-1 group was significantly higher than dsEGFP group, which may be due to ovarian abnormalities caused by nutrient deficiency. The quantitative polymerase chain reaction (qPCR) results showed that the expression level of Ago-1 significantly increased after different pesticide treatments, and knocking down significantly increased the mortality rate of beetles treated with pesticides.

CONCLUSION

The results indicate that Ago-1 is indispensable for normal ovarian development in T. castaneum and helps to address the issue of resistance development by enhancing insecticide susceptibility. © 2025 Society of Chemical Industry.