Heterologous expression in transgenic mosquitoes

Arthropod-borne diseases such as malaria and dengue virus afflict billions of people worldwide imposing major economic and social burdens. Control of such pathogens is mainly performed by vector management and treatment of affected individuals with drugs. The failure of these conventional approaches due to emergence of insecticide-resistant insects and drug-resistant parasites demonstrate the need of novel and efficacious control strategies to combat these diseases. Genetic modification (GM) of mosquito vectors to impair their ability to be infected and transmit pathogens has emerged as a new strategy to reduce transmission of many vector-borne diseases and deliver public health gains. Several advances in developing transgenic mosquitoes unable to transmit pathogens have gained support, some of them attempt to manipulate the naturally occurring endogenous refractory mechanisms, while others initiate the identification of an exogenous foreign gene which disrupt the pathogen development in insect vectors. Heterologous expression of transgenes under a native or heterologous promoter is important for the screening and effecting of the transgenic mosquitoes. The effect of the transgene on mosquito fitness is a crucial parameter influencing the success of this transgenic approach. This review examines these two aspects and describes the basic research work that has been accomplished towards understanding the complex relation between the parasite and its vector and focuses on recent advances and perspectives towards construction of transgenic mosquitoes refractory to vector-borne disease transmission.