Temperature-dependent alternative splicing affects gene expression in Aedes aegypti mosquitoes midgut

Temperature is one of the most significant abiotic factors influencing vector resistance to pathogens. Research has provided substantial insights into the immunological and oxidative processes affected by temperature. However, our understanding of the complex interplay in mosquito-pathogen interactions remains limited. In this study, we investigated the impact of temperature on alternative splicing in the midgut of Aedes aegypti mosquitoes (adult females) under different thermal conditions. Few genes exhibited differential alternative splicing when comparing low (20°C) and high (36°C) temperatures to standard rearing conditions (28°C). Among these, Trypsin (TRY), Ferritin (FER), Thioredoxin (TRX) and Peptidoglycan recognition protein LC (PGRP-LC) were identified, aligning with previous findings that their expression is temperature-sensitive. Among the genes identified with alternative splicing, we focus on Thioredoxin and PGRP-LC, genes modulated by temperature variations and promising targets for future studies on their role in the competence of Ae. aegypti to transmit Zika. Experimental validation confirmed that TRX, a gene critical for pathogen defence, has a differentially spliced exon under warmer conditions, potentially altering its activity. In contrast, no differential splicing was observed for PGRP-LC across temperature treatments. These findings suggest that temperature-induced alternative splicing may play a role in shaping the mosquito's physiological responses to environmental changes, highlighting a previously underexplored layer of complexity in mosquito-pathogen dynamics.