Diapause-associated changes in the lipid and metabolite profile of the Asian tiger mosquito, Aedes albopictus

Abstract

Diapause is an alternative life-history strategy that allows organisms to enter developmental arrest in anticipation of unfavorable conditions. Diapause is widespread among insects and plays a key role in enhancing overwinter survival as well as defining the seasonal and geographic distributions of populations. Next generation sequencing has greatly advanced our understanding of the transcriptional basis for this crucial adaptation but less is known about regulation of embryonic diapause physiology at the metabolite level. Here, we characterized the lipid and metabolite profile of embryonic diapause in the Asian tiger mosquito, Aedes albopictus. We used an untargeted approach to capture the relative abundance of 250 lipids and 241 metabolites. We observed adjustments associated with increased energy storage, including an accumulation of lipids, the formation of larger lipid droplets, and increased lipogenesis, as well as metabolite shifts suggesting reduced energy utilization. We also found changes in neuroregulatory- and insulin-associated metabolites with potential roles in diapause regulation. Finally, we detected a group of unidentified, diapause-specific metabolites which have similar physical properties steroids/steroid derivatives and may be associated with the ecdysteroidal regulation of embryonic diapause in Ae. albopictus. Together, these results deepen our understanding of the metabolic regulation of embryonic diapause and identify key targets for future investigations.