Odorant receptor-mediated sperm activation in disease vector mosquitoes

Significance Mosquitoes use neuronal-expressed odorant receptors in their antennae to locate blood meal sources via chemical cues emitted by hosts. Although their expression in nonsensory tissues is known, the potential for odorant receptors to also mediate endogenous signaling events in insects has remained unexplored. In this study, we have identified a subset of odorant receptors showing transcript expression in the testes of the malaria mosquito, Anopheles gambiae . In addition, we provide functional evidence that the broadly conserved insect coreceptor, Orco, mediates flagellar activation in mosquito spermatozoa. These results are reminiscent of odorant receptor function in human sperm and may represent an intriguing example of convergent evolution.