miR‐11903a modulates <i>CLIPB9</i> ‐mediated pathogen defense and longevity in <i>Aedes aegypti</i>

Arthropod melanization is a crucial defense mechanism mediated by a complex cascade of CLIP domain serine proteases (CLIPs). In this study, it was confirmed that microRNA-11903a (miR-11903a) targets Aedes-CLIPB9 (AeCLIPB9) by bioinformatics prediction and dual-luciferase reporter assays. Following intrathoracic injection of miR-11903a agomir and antagomir, Real-time quantitative polymerase chain reaction confirmed that AeCLIPB9 is negatively regulated by miR-11903a. Spatiotemporal expression analysis revealed that miR-11903a is most abundant in 4th instar larvae, followed by pupae and adults, and highly expressed in the wings, head, and midgut of female adults. Following pathogen infection, AeCLIPB9 and miR-11903a exhibited opposite expression trends, indicating their potential roles in mosquito innate immunity. To further investigate the relationship between AeCLIPB9 and miR-11903a, double-strand CLIPB9 was synthesized and RNA interference was performed. Seven-d survival assays revealed that both AeCLIPB9 and miR-11903a were crucial immune factors in fighting pathogens. Finally, longevity assays demonstrated that miR-11903a influenced mosquito lifespan.