Blood feeding-induced transcriptomic changes in the hard tick Ixodes persulcatus

Introduction: Ticks are hematophagous ectoparasites that must overcome significant physiological challenges during blood feeding. These include managing oxidative stress, detoxifying host-derived molecules, and reallocating energy to support digestion, tissue remodeling, and reproduction. Methods: ticks at three key feeding stages: unfed, semi-engorged, and fully engorged. Functional annotation and Gene Ontology (GO) enrichment analyses were conducted to characterize stage-associated transcriptional changes, with a focus on metabolic detoxification and antioxidant systems. Results and discussion: We generated a reference transcriptome containing 56,900 unigenes. Comprehensive analyses of metabolic detoxification and antioxidant systems revealed species-specific expansions in key supergene families such as cytochrome P450s and glutathione S-transferases. The expression profiles across feeding stages revealed pronounced physiological changes in response to blood meal, and GO enrichment analysis showed that these changes were mainly involved in blood acquisition, nutrient metabolism, respiratory processes, hormone synthesis, egg development, immune responses, ROS detoxification, transcription and translation. These findings offer new insights into the molecular physiology of tick hematophagy and provide a valuable resource for future studies on stress responses and metabolic regulation in ticks.