Project description:High throughput sequencing was performed using Illumina HiSeq to identify differentially regulated genes in Culex mosquitoes after West Nile virus infection.
Project description:Rift valley fever (RVF) is an emerging zoonotic disease and it is caused by Rift valley fever phlebovirus (RVFV). This virus is commonly transmitted in endemic areas between wild ruminants and mosquitoes, mainly by mosquitoes of Culex and Aedes genus. Starting from 2000, several outbreaks have been reported outside the African continent, in countries facing the Mediterranean Sea, such as Saudi Arabia. The available vaccines for ruminants present limited efficacy or residual pathogenic effects. Consequently, new strategies are urgently required to limit the expansion of this zoonotic virus. The main objective of this work is to investigate the molecular responses of Culex pipiens to RVFV focusing mainly on genes implicated in the classical innate immunity pathways, RNAi mechanism and apoptosis process in order to elucidate the implicated genes in viral infection. The immune altered genes here described could be potential targets to control RVFV infection in mosquitoes. Some of the genes related to the immune defense response were previously described in others mosquito-arbovirus models, as also in Drosophila and human. To our knowledge, this study elucidates for the first time the Cx. pipiens-RVFV interaction in terms of defense infection-response, which was largely under studied and provides information to develop new approaches to prevent and control the expansion of the virus in the future.
Project description:Determination of miRNA profiles in most prominent mosquitoes will determine the potential targets for mosquito control Some of the most medically important viruses, such as dengue virus, West Nile virus, Zika virus, and yellow fever virus, are transmitted by mosquitoes. These aptly named arboviruses impose a tremendous cost to the health of populations around the world. As a result, much effort has gone into the study of the impact of these viruses in human infections. Comparatively less efforts, however, have been made to study the way these viruses interact with mosquitos themselves. It has long been held that these viruses are introduced into the midgut of mosquitoes upon ingestion of a blood meal before being transmitted within the saliva upon subsequent feeding. This sequence requires that the mosquito be able to defend itself from infection every step along the way-from ingesting bloodmeal to subsequent feeding. The main defense mechanisms employed by the mosquitoes to control viruses is RNA interference (RNAi). Modulation of this facet of the mosquito’s immune system would thereby suggest a practical strategy for vector control. This paper will provide an up to date overview of the mosquito’s immune system along with novel data describing miRNA profiles for Aedes aegypti and Culex quinquefasiatus in Grenada, West Indies.
Project description:In recent years, arboviral infections have surged dramatically due to the geographic expansion of Aedes and Culex mosquitoes, their main vector mosquitoes. Despite significant efforts to uncover arbovirus–host interactions and viral protein effector functions in mammals, systematic studies aiming to characterize virus–vector interactions in arthropods are largely missing, and the functions and cellular targets of many arboviral proteins in mosquitoes remain elusive. Here, we applied a multi-omic approach to systematically evaluate the ability of arboviral capsids to interact with the Ae. aegypti proteome. This extensive multi-modal atlas across 12 pathogenic arboviral species spanning three viral genera revealed shared and distinct host factor specificities, uncovering species-, genus- and vector preference-specific patterns of host usage in mosquitoes. Functional phenotypic screening of 110 newly discovered host proteins across three prototypic arboviruses (La Crosse virus, dengue virus and West Nile virus) identified several novel host dependency factors, including a new role for the chromatin-remodeling Brahma complex in orthoflavivirus replication. Using a combination of biochemical and sequencing approaches, we characterized the cellular determinants of these interactions and profiled their functional consequences on the chromatin landscape. Altogether, this study provides a multi-layered repository to categorize and characterize arboviral capsid effector functions in invertebrates, providing important cues on novel mechanisms of transcriptional regulation via capsid-mediated modulation of chromatin accessibility in insects.
Project description:Culex pipiens molestus and Cx. p. quinquefasciatus are the members of Culex pipiens Complex, but they display relatively large differences in behavior and physiological responses. We compared the genes of these mosquitoes to identify those that were differentially expressed in each subspecies. Such genes could play important roles in subspecies-specific blood feeding or oviposition behavior. Culex pipiens molestus and Cx. p. quinquefasciatus females were undertaken Illumina RNA sequencing.
Project description:Culex pipiens molestus and Cx. p. quinquefasciatus are the members of Culex pipiens Complex, but they display relatively large differences in behavior and physiological responses. We compared the genes of these mosquitoes to identify those that were differentially expressed in each subspecies. Such genes could play important roles in subspecies-specific blood feeding or oviposition behavior.
Project description:Mosquitoes serve as medically significant vectors for transmitting various arboviruses. The mosquito midgut is both the digestive organ and primary infection site via viral bloodmeals, and the midgut cells show heterogeneity on virus-vector interactions. Rapidly developed single-cell RNA sequencing (scRNA-seq) technologies allow to characterize midgut physiology and viral infection dynamics at cellular solution. At present, scRNA-seq studies about mosquito midgut cell atlas are still limited and lack established protocols for cellular isolation. Therefore, we developed and employed a compatible microwell-based scRNA-seq protocol on four important mosquito species including Aedes aegypti, Aedes albopictus, Culex pipiens pallens and Culex tritaeniorhynchus and successfully established their midgut cell atlases pre- and post-bloodmeal. Further, we performed scRNA-seq experiments on DENV-infected Ae. aegypti to characterize the viral infection dynamics at single-cell solution.
Project description:Zika virus (ZIKV), a pathogen of global health concern, is transmitted to humans by Aedes mosquitoes. However, the molecular interactions between the vector and the virus remain largely unexplored. We demonstrated that ZIKV and dengue virus (DENV) have similar tropism and infection kinetics in two mosquito strains with different degrees of susceptibility to infection. Comparison of Aedes aegypti’s molecular responses to ZIKV and DENV infection indicated that around 40% of the mosquito’s infection-responsive transcriptome is virus-specific. Regulated genes also included key factors of the mosquito’s anti-viral immunity, pointing to the possible involvement of the Toll innate immune pathway. Comparison of ZIKV and DENV infection-responsive transcriptome data to those for yellow fever virus and West Nile virus identified 26 genes likely to play key roles in virus infection of Aedes mosquitoes. Through reverse genetic analyses, we showed that the Toll and the Jak/Stat innate immune pathways mediate increased resistance to ZIKV infection, and the virus use vATPase and inosine-5’-monophosphate dehydrogenase as mosquito’s host factors.