First Insights into the Comparative Transcriptomic Response of Field and Laboratory Aedes aegypti Strains to...

Insecticide resistance in Aedes aegypti (Linnaeus, 1762), the primary vector of several arboviruses, threatens vector control efficacy and motivates evaluation of current and candidate public health insecticides, such as imidacloprid and broflanilide, and their molecular impacts. Here, we used RNA sequencing (RNA-seq) to characterize the transcriptomic response to one-hour acute exposure to an operational partial-mortality concentration (<50%) of imidacloprid and broflanilide in two Ae. aegypti strains: a field-derived, pyrethroid-resistant population from San Nicolás and a susceptible laboratory strain (New Orleans). Adults were exposed for 1 h to partial-mortality concentration (<50%) doses of each insecticide or acetone control, and differential gene expression and Gene Ontology (GO) enrichment were assessed with DESeq2-based workflows. We detected pronounced baseline transcriptomic differences between strains and extensive activation of gene expression after insecticide exposure, with a strong bias toward up-regulation. A shared transcriptional core involving proteolysis, transmembrane transport, detoxification pathways, and structural remodeling of the cuticle and cytoskeleton was identified across contrasts. Despite these common elements, broflanilide elicited largely conserved early responses between strains, whereas imidacloprid amplified pre-existing divergence and produced marked population-specific transcriptional signatures. These findings suggest greater transcriptional changes in the field-derived strain, particularly in response to imidacloprid, and highlight the importance of integrating population-specific molecular information when designing insecticide rotation schemes and resistance management strategies targeting Ae. aegypti.