Embryogenesis and apoptosis appears as key molecular pathways involved in Varroa destructor reproduction

In this study, we identified candidate genes associated with the reproductive success of Varroa destructor in Apis mellifera brood cells at a key point in time, the 4 th day after host cell capping. First-life cycle reproducing (R) and non-reproducing (NR) mites obtained by applying a semi-field rearing protocol were analyzed by RNA-Seq and qPCR. We observed a general under-expression of genes associated with metabolism and a few over-expressed genes putatively involved in signal transduction and DNA-binding transcription factor activity in R compared to NR mites. Specifically, PTCH1 and AP-1 genes, associated with embryonic segmentation and apoptosis, emerged as the best candidates for reproductive success in R mites and the early abortion of reproduction in NR mites. We also detected differentially transcribed long non-coding RNAs between R and NR mites with cis target genes annotated as regulators of replication, transcription, and translation pathways. Some of these genes were specifically associated with embryonic development and apoptosis. We discuss putative metabolic pathways associated with V. destructor reproduction to provide novel information for developing innovative and environmentally friendly mite control strategies.