Selection on time to parasite transmission shapes the hostAnopheles gambiaetranscriptional response and suggests immune evasion

Understanding host-parasite interactions is of the utmost importance for the correct disease prediction, prevention and management. Hence, this study assessed the transcriptional response of the primary malaria vector, Anopheles gambiae , to infection with several lines of the prominent vector-control parasite, the microsporidian Vavraia culicis . These parasitic lines have been selected for early or late transmission within this host. Previous studies extensively described them phenotypically, differing in their virulence, infection dynamics and host exploitation. Using RNA sequencing, gene expression profiles were analyzed in mosquitoes infected with early-selected, late-selected, unselected (reference) V. culicis lines and uninfected controls. The results revealed distinct transcriptional changes associated with each parasite line. Early-selected parasites induced a broader immune response than late-selected ones. Differential expression of immune-related genes, including Toll-interacting protein and Protein ERGIC-53 , suggests enhanced immune evasion in late-selected parasites. Additionally, significant changes were observed in pathways related to Golgi membrane function and oxidative stress response, particularly in response to early-selected parasites. These findings highlight the evolutionary pressures shaping host-parasite coevolution and provide insights into how parasite transmission traits can influence mosquito immune response and regulation. This work offers a foundation for future studies on host-parasite dynamics and potential applications for vector control strategies.