Gene expression and gene silencing data of Varroa destructor

Abstract

The ectoparasite Varroa destructor is the main threat to the western honeybee Apis mellifera, worldwide. Current acaricide-based controls have usually generated mite resistance, thus developing novel sustainable control strategies for V. destructor in honeybee colonies is a priority. To investigate the potential of RNA interference (RNAi) for controlling the mite, we examined the effects of silencing candidate genes which potentially play a key role in V. destructor survival and reproduction. We synthesized double-stranded RNA (dsRNA) of six candidate genes (ptch1, ap-1, larp6, chisal, vg1 and vg6) and used a novel topical method with acetone to individually deliver the dsRNA into Varroa mites. Survival and successful reproduction were assessed in silenced and control mites using a semi-field rearing method. A significant lower expression was observed for all candidate genes in mites subjected to dsRNA treatments compared to controls, with high knockdown efficiencies ranging from 89.5 to 97.4%. Significant differences were observed in fertility of mites treated with dsRNA targeting the ptch1, ap-1, and vg1 genes compared to control mites. These genes are related to oocyte maturation and intraovarian embryogenesis. The silencing of chisal gene led to a significant increase in mite mortality compared to controls. Our findings provide insights into the roles of genes and molecular pathways associated with mite reproduction, offering possible targets for the control of V. destructor through RNAi in the future.