Projected late-century climate change alters reproductive gene expression pathways in the arbovirus vector Aedes aegypti.

Climate change is expected to alter the ecology, persistence, and geographic distribution of mosquito vectors, yet the molecular traits underlying vector responses to future environmental conditions remain insufficiently understood. Aedes aegypti, a major vector of arboviruses, depends on tightly regulated reproductive and lipid-transfer pathways that are linked to population replacement and persistence. Here, we experimentally evaluated whether projected late-century increases in temperature and atmospheric CO₂ affect the transcriptional regulation of lipophorin- and vitellogenin-associated genes in female Ae. aegypti. Mosquitoes were reared under controlled IPCC-based climate scenarios simulating current, mild, intermediate, and extreme future conditions, and the relative transcription of LpII, LpIII, LpR, VgA1, VgB, VgC, and VgR was quantified by RT-qPCR. Increasing environmental severity was associated with a progressive reduction in the transcription of genes involved in lipid transport, yolk precursor production, and receptor-mediated nutrient uptake. Vitellogenin-associated genes showed stronger transcriptional sensitivity than lipophorin genes, particularly after blood feeding, and receptor downregulation under extreme conditions was consistent with altered molecular pathways involved in ovarian nutrient acquisition. Regression and correlation analyses further indicated negative relationships between simulated temperature increase and transcriptional levels of key reproductive genes. These findings identify reproductive lipid metabolism as a climate-sensitive molecular trait in Ae. aegypti and suggest that future warming and elevated CO₂ may affect molecular pathways linked to reproductive investment, a possibility that requires functional validation. This study contributes to understanding how environmental change may shape molecular responses in disease vectors under future climate scenarios.