Revealing the light-regulated circadian rhythm in the vector mosquitoes, Aedes albopictus and Culex quinquefasciatus

Light serves as a primary zeitgeber for regulating circadian rhythms in mosquitoes. As important vector insects, the diurnal Aedes albopictus and the nocturnal Culex quinquefasciatus are not only nuisance biters, but also transmit viruses such as dengue, Zika, and West Nile. We conducted a comparative analysis of the oscillating molecular rhythms in these two mosquito species. Light-blocking paint application experiments reveal species-specific photic pathways. CRISPR/Cas9 knockouts of the Aalopsin1, Cxqopsin6, and Cry1 genes revealed that Ae. albopictus relies principally on the compound eye pathway, whereas Cx. quinquefasciatus depends more on the non-visual ocelli-like pathway for circadian rhythm regulation. In addition, different light conditions can affect the lifespan of adult mosquitoes. These findings reveal the light-regulated circadian rhythm in diurnal and nocturnal vector mosquitoes.