These smaller fragments are then loaded into a multi-protein complex called the RNA Induced Silencing Complex (RISC) where the active component Argonaute-2 (Ago2) binds to the siRNA and unwinds and degrades one of the strands. Upon recognition, the nuclease Dicer-2 (Dcr2) chops the hairpin dsRNA into short interfering RNA duplexes (siRNAs). This results in the expression of a hairpin double-stranded RNA (dsRNA), which is recognized by the small interfering RNA (siRNA) pathway. In the latter case, animals are genetically transformed to contain a transgene in their genome expressing a gene fragment cloned as an inverted repeat. In a model and genetically transformable species, such as Drosophila melanogaster, reverse functional genomics (from gene to phenotype) is classically achieved using mutant lines or RNA interference (RNAi). However, the functions of many of them are still unknown. The major advances in the last two decades in vector biology, genomics/comparative genomics, transcriptomics and proteomics have allowed the identification of a large number of genes and proteins putatively involved in mosquito-arbovirus interactions. Therefore, it is important to increase our understanding of mosquito biology and mosquito-arbovirus interactions that influence the outcome of arbovirus infection in mosquitoes. As Aedes mosquitoes develop resistance to insecticides (Dusfour et al., 2019), new vector control strategies are urgently needed. Therefore, mosquito control remains a key strategy to limit arbovirus transmission (Kean et al., 2015 Achee et al., 2019 Lambrechts and Saleh, 2019). Despite the huge burden these viruses cause to the healthcare systems and the economy in endemic countries there are few effective vaccines or antivirals available to target infections caused by these viruses. The major vector for these viruses is the Aedes aegypti ( Ae. Medically important mosquito-borne arboviruses include chikungunya, dengue, Zika and yellow fever virus (Weaver and Reisen, 2010 Weaver et al., 2016 Mayer et al., 2017 Wilder-Smith et al., 2017 Paixao et al., 2018). Mosquito-borne arboviruses cause a large medical, veterinary and economic impact on predominately tropical and sub-tropical regions of the world. aegypti, leading toward a better understanding of physiological and infectious processes. Overall, this work should help future gene function analyses using RNAi in adult females Ae. Finally, we show that gene silencing cannot be achieved using siRNA injection in Ae. We demonstrate that use of high doses of dsRNA can improve knockdown efficiency, and injection of a transfection reagent along with dsRNA reduces the variability in efficiency between replicates. Our findings suggest that silencing is likely also gene dependent, probably due to gene-specific tissue expression and/or feedback mechanisms. aegypti ( p400, ago2 and E75), we show that gene silencing can indeed be dsRNA sequence dependent but different efficiencies do not correlate with dsRNA length. Here, by analysing silencing of three different genes in female Ae. Difficult knockdowns using dsRNA can thus hamper gene function analysis. In the adult female Aedes aegypti, a main vector of human-infecting arboviruses, efficiency of gene silencing following dsRNA injection varies greatly according to targeted genes. In insects, this technique is often applied through the delivery of dsRNA.

Gene silencing using RNA interference (RNAi) has become a widely used genetic technique to study gene function in many organisms.

Pjet vector in serial cloner