Proteomics identifies critical hemolymph proteins for extreme temperature adaptation in Hyalomma asiaticum.

Hyalomma asiaticum can survive in extreme environments including the semi-arid zones and deserts. Investigating the molecular mechanisms of the tolerance of ticks to extreme temperatures could help tick control by interfering with their temperature tolerance. A comprehensive analysis of the regulatory mechanisms of proteins in the hemolymph is essential to unraveling the survival strategies of ticks in harsh environments. In this study, a quantitative proteomics analysis was performed by data independent acquisition (DIA) using hemolymph of ticks exposed to extreme temperatures. Proteins involved in energy metabolism, cuticle protection, and cell cycle changed under extreme temperatures. Further analysis using RNA interference (RNAi) revealed that when a secreted glycine-rich protein (GRP) was knocked down, the survival probability of ticks at -10°C was 20 %, and when glucosamine-phosphate N-acetyltransferase (GNPNAT) and V-atpase subunit H (V-ATPase) were knocked down, the survival probability of ticks at 46°C were 15 % and 20 %, respectively. The results showed that maintaining lipid homeostasis, ensuring energy supply and enhancing ATPase catalytic efficiency were the most important means for ticks to survive at extreme temperatures. This may contribute to our understanding of temperature adaptation mechanisms in ticks.