Project description:RNA interference (RNAi) functions as the major host antiviral defense in insects, while less is understood about how to utilize antiviral RNAi in controlling viral infection in insects. Enoxacin belongs to the family of synthetic antibacterial compounds based on a fluoroquinolone skeleton that has been previously found to enhance RNAi in mammalian cells. In this study, we showed that enoxacin efficiently inhibited viral replication of Drosophila C virus (DCV) and Cricket paralysis virus (CrPV) in cultured Drosophila cells. Enoxacin promoted the loading of Dicer-2-processed virus-derived siRNA into the RNA-induced silencing complex, thereby enhancing antiviral RNAi response in infected cells. Moreover, enoxacin treatment elicited an RNAi-dependent in vivo protective efficacy against DCV or CrPV challenge in adult fruit flies. In addition, enoxacin also inhibited replication of flaviviruses, including Dengue virus and Zika virus, in Aedes mosquito cells in an RNAi-dependent manner. Together, our findings demonstrated that enoxacin can enhance RNAi in insects, and enhancing RNAi by enoxacin is an effective antiviral strategy against diverse viruses in insects, which may be exploited as a broad-spectrum antiviral agent to control vector transmission of arboviruses or viral diseases in insect farming.
Project description:Zika virus (ZIKV) is a mosquito-transmitted positive-sense RNA virus in the family Flaviviridae. ZIKV infections are associated with neurodevelopmental deficiencies termed Congenital Zika Syndrome. ZIKV strains are grouped into three phylogenetic lineages: East African, West African, and Asian, which contains the American lineage. RNA virus genomes exist as genetically-related sequences. The heterogeneity of these viral populations is implicated in viral fitness, and genome diversity is correlated to virulence. This study examines genetic diversity of representative ZIKV strains from all lineages utilizing next generation sequencing (NGS). Inter-lineage diversity results indicate that ZIKV lineages differ broadly from each other; however, intra-lineage comparisons of American ZIKV strains isolated from human serum or placenta show differences in diversity when compared to ZIKVs from Asia and West Africa. This study describes the first comprehensive NGS analysis of all ZIKV lineages and posits that sub-consensus-level diversity may provide a framework for understanding ZIKV fitness during infection.
Project description:Begomoviruses, the largest, most damaging and emerging group of plant viruses in the world, infect hundreds of plant species and new virus species of the group are discovered each year. They are transmitted by species of the whitefly Bemisia tabaci. Tomato yellow leaf curl virus (TYLCV) is one of the most devastating begomoviruses worldwide and causes major losses in tomato crops as well as in many more agriculturally important plant species. Different B. tabaci populations vary in their virus transmission abilities; the causes for these differences are attributed among others to genetic diversity of vector populations, as well as to differences in the bacterial symbiont flora of the insects. Here, we performed discovery proteomic analyses in nine whiteflies populations from both B (MEAM1) and Q (MED) species with different TYLCV transmission abilities. The results provide the first comprehensive list of candidate insect and bacterial symbiont (mainly Rickettsia) proteins associated with virus transmission. Efficient vector populations from two different B. tabaci species over-expressed or downregulated expression of proteins belonging to two different molecular pathways.
Project description:Small RNAs play a critical role in host-pathogen interaction. In insects, for instance, small RNA-mediated silencing or RNA interference (RNAi) represents the main antiviral defense system. However, the antiviral role of RNAi has not been clearly proven in higher vertebrates. On the contrary, it is well established that the cell response relies on the recognition of viral RNAs by host pattern recognition receptors (PRR) to trigger the activation of the interferon pathway. Based on this evidence, we wished to contribute to this research field by identifying and characterizing small non-coding RNAs produced in mammalian cells upon RNA virus infection. We focused on Sindbis virus (SINV), the prototypical arbovirus, which by definition, is able to infect both vertebrate hosts and invertebrate vectors and triggers the interferon pathway or RNAi, respectively.
Project description:Is there a correlation between miRNA diversity and levels of organismic complexity? Exhibiting extraordinary levels of morphological and developmental complexity, insects are the most diverse animal class on earth. Their evolutionary success was in particular shaped by the innovation of holometabolan metamorphosis in endopterygotes. Previously, miRNA evolution had been linked to morphological complexity, but astonishing variation in the currently available miRNA complements of insects made this link unclear. To address this issue, we sequenced the miRNA complement of the hemimetabolan Blattella germanica and reannotated that of two other hemimetabolan species, Locusta migratoria and Acyrthosiphon pisum, and of four holometabolan species, Apis mellifera, Tribolium castaneum, Bombyx mori and Drosophila melanogaster. Our analyses show that the variation of insect miRNAs is an artefact mainly resulting from poor sampling and inaccurate miRNA annotation, and that insects share a conserved microRNA toolkit of 65 families exhibiting very low variation. For example, the evolutionary shift toward a complete metamorphosis was accompanied only by the acquisition of three and the loss of one miRNA families.
2016-11-30 | GSE83339 | GEO
Project description:Virus diversity associated with vine mealybug Planococcus ficus
Project description:All the reports on insect small RNAs come from holometabolous insects. However, small RNAs of hemimetabolous insects have not yet been investigated.Study of hemimetabolous insect small RNAs could provide more insights into evolution and function of small RNAs in hemi- and holometabolous insects. The locust is an important, economically harmful hemimetabolous insect and its phase changes is an interesting phenomenon.Here, we used high-throughput sequencing to characterize and compare the small RNA transcriptomes of gregarious and solitary phases in locusts. We found abundant small RNAs and their different expression profiles in the two phases.
Project description:With the advent of advanced sequencing technology, studies of RNA viruses have shown that genetic diversity contribute to both attenuation and virulence. The differences in genetic diversity of wild-type Asibi virus and 17D-204 vaccine provides an unique opportunity to investigate RNA population theory in the context of a well described live attenuated vaccine. Utilizing infectious clone-derived viruses containing some of the amino acid substitutions that differentiate yellow fever wild-type Asibi strain from 17D vaccine and recovered in a controlled experiment, establishes that the genetic diversity differences that exist between wild-type Asibi and 17D-204 vaccine viruses are not influenced by either different passage history or source of samples, but rather resulted from the attenuation of wild-type Asibi virus to yield the 17D vaccine sub-strains.
Project description:ZIKV strains belong to three phylogenetic lineages: East African, West African, and Asian/American. RNA virus genomes exist as populations of genetically-related sequences whose heterogeneity may impact viral fitness, evolution, and virulence. The genetic diversity of representative ZIKVs (N=7) from each lineage was examined using next generation sequencing (NGS) paired with downstream Shannon entropy calculation and single nucleotide variant (SNV) analysis. This comprehensive analysis of ZIKV genetic diversity provides insight into the genetic diversity of ZKIV and repository of SNV positions across lineages.