Genomics of neuropeptide signaling system in Varroa mites Varroa destructor and Varroa jacobsoni

Abstract

The honey bee is a beneficial insect to humans in various aspects, for example they provide food products like honey, royal jelly, bee wax and propolis used in cosmetic industry as well as pollination services worth $200 billion annually. In the last decade, the global honey bee population has declined at an alarming rate, with a roughly 40% decline in the honey bee population in the USA alone. This decline, commonly called colony collapse disorder (CCD) has been caused by various factors, in particular Varroa mite infestations. Various natural and synthetic acaricides were used in the past to control the population of Varroa mites. However, the development of acaricide resistance has made it difficult to control the mite infestations over the years. The development of novel chemistries against the Varroa mite is not an easy task due to stringent constraints of direct and indirect effects on long-term human health through bee products. One of the possible targets that could be exploited for novel chemistries is the neuropeptide signaling system. Neuropeptides are the signaling molecules for modulating critical physiological processes like growth, development, reproduction, and metabolism. We aimed to identify a specific neuropeptide signaling system present in the Varroa mite, but absent in the honey bee using the comparative genomics. Our study focused on conducting the bioinformatics analysis of the neuropeptide signaling system in Varroa destructor and Varroa jacobsoni. We were able to identify 29 and 31 genes that encode neuropeptides in V. destructor and V. jacobsoni, respectively. In addition, we identified 27 G protein-coupled receptors that putatively function as neuropeptide receptors. ACP, Allatostatin B, Glycoprotein hormone Beta 5 (GPB5), Proctolin, Natalisin are the neuropeptides for which gene sequences were found in V. destructor and V. jacobsoni, but were missing in the honey bee.