Co-expression of rhodopsin and arrestin and their potential roles in insecticide resistant mosquitoes, Culex quinquefasciatus

Insecticide resistance has been an obstacle in the mosquito control. Understand genes and their possible roles in mosquito resistance will be fundamental for designing novel strategies to control mosquitoes, especially the resistant ones. Previous studies identified multiple genes, including rhodopsin and arrestin genes that were overexpressed in the resistant HAmCq mosquitoes of Culex quinquefasciatus. Both rhodopsin and arrestin are involved in the G-protein-coupled signal transduction system and regulate many essential physiological processes and functions. In the current study, we characterized the expression and the potential role of rhodopsin and arrestin in the regulation of insecticide resistance of Culex mosquitoes. The expression patterns of rhodopsin and arrestin at both RNA and protein levels were examined in susceptible S-Lab, field resistant HAmCq^G0, and the 8^th generation of permethrin-selected HAmCq^G0 offspring, HAmCq^G8, mosquitoes. Both rhodopsin and arrestin were significantly co-overexpressed in resistant HAmCq mosquitoes; the co-overexpression was predominately identified in the heads of resistant mosquitoes; and the co-overexpression was gradually increased in HAmCq mosquitoes following permethrin selection. These findings suggest the importance of rhodopsin and arrestin in insecticide resistance of mosquitoes. Further characterize the function and transcriptional co-expression of rhodopsin and arrestin in resistance will likely shed new light on our understanding of molecular mechanisms of resistance development in mosquitoes.