Abstract
There has been a considerable growth in interest to use RNA interference (RNAi) as a novel insect pest management strategy in the past 10 years. However, there has been virtually no information on insect population variations in response to double-stranded RNA (dsRNA) molecules. The objective of this study was to generate baseline susceptibilities of the red flour beetle (Tribolium castaneum) to an insecticidal dsRNA targeting vacuolar H+-ATPase subunit E gene (dsvATPaseE), and correlate the susceptibility data with sequence and expression variations of the target gene (vATPaseE), expression variations of the RNAi core genes, and overall genetic differences among a laboratory strain and seven geographical field populations of T. castaneum collected in China. Our results showed limited variations in the LD50 values of dsvATPaseE, which ranged from 0.10 to 0.29 ng/larva among the laboratory strain and the seven field populations. Considering the overlapping of the 95% confidence intervals of their LD50 values, there were no significant differences among the laboratory strain and field populations. We also found limited sequence polymorphisms and low frequencies of the polymorphisms of vATPaseE, and limited variations (<2-fold) of the endogenous expression of vATPaseE among the laboratory strain and field populations. However, we found considerable genetic variations among the individuals within each field population for most of eight loci and moderate to large genetic variations among the field populations. These results demonstrated that although the genetic variabilities were considerable among these field populations, the efficiency of RNAi targeting vATPaseE was highly consistent in T. castaneum. Our study provides work frames of resistance risk assessment for RNAi-based insect pest management programs.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call