Project description:Parasitoid wasps inject venom to regulate the immune response and development of host arthropods and sometime paralyze host arthropods. Hereby, proteomic method was used to identify putative venom proteins from Theocolax elegans, ectoparasitoids of storage insect pests.
Project description:Parasitoid wasps of the species Diachasmimorpha longicaudata are associated with a heritable poxvirus, known as DlEPV, that is stored in the venom gland of adult female wasps and transferred to tephritid fly hosts of the wasps during oviposition. We conducted a RNA-seq differential expression analysis to gain insight on how DlEPV can replicate in both wasps and their fly hosts but only cause pathogenic effects during replication in flies. Our analysis revealed that 91.2% (176 of 193) of DlEPV genes showed significant differential expression during peak virus replication in wasp venom glands compared to parasitized flies. Over 80% of DlEPV replication genes were significantly upregulated in wasps, while 79% of DlEPV putative virulence genes were significantly upregulated in fly hosts. These data therefore support a dichotomy of viral function, where virus replication is promoted in wasp tissue and virulence in host tissue. Such a division of viral activity could represent an important adaptation to maintain a stable symbiosis between this virus and its associated parasitoid.
Project description:Parasitoid wasps are one of the most species-rich groups of animals on Earth, due to their ability to successfully develop as parasites of nearly all types of insects. Unlike most known parasitoid wasps that specialize within one or a few host species, Diachasmimorpha longicaudata is a generalist that can survive within multiple genera of tephritid fruit fly hosts, including many globally important pest species. D. longicaudata has therefore been widely released to suppress pest populations as part of biological control efforts in tropical and subtropical agricultural systems. In this study, we investigated the role of a mutualistic poxvirus in shaping the host range of D. longicaudata across three genera of agricultural pest species: two of which are permissive hosts for D. longicaudata parasitism and one that is a nonpermissive host. We found that permissive hosts Ceratitis capitata and Bactrocera dorsalis were highly susceptible to virus infection, displaying rapid virus replication and abundant fly mortality. However, the nonpermissive host Zeugodacus cucurbitae largely overcame virus infection, exhibiting substantially lower mortality and no virus replication. Further investigation of transcriptional dynamics during virus infection demonstrated hindered viral gene expression and limited changes in fly gene expression within the nonpermissive host compared to the permissive species, indicating that the host range of the viral symbiont may dictate the host range of D. longicaudata wasps. These findings also reveal that viral symbiont activity may be a major contributor to the success of D. longicaudata as a generalist parasitoid species and a globally successful biological control agent.
Project description:High temperature events can disrupt species interactions, including those among hosts, symbionts, and natural enemies. Understanding the genetic and physiological processes underlying these disruptions is a critical scientific challenge in this era of anthropogenic climate change. We explore how high temperatures disrupt the interactions among an herbivorous insect host, Manduca sexta, its insect parasitoid, Cotesia congregata, and the parasitoid’s symbiotic virus. In this system, high temperatures kill developing parasitoids, but not hosts. We evaluated the physiological and transcriptomic causes of thermal mismatch in ecological interactions using parasitoid egg in vitro experiments, immunological assays, and RNAseq. We found that high temperatures disrupt the capacity of the parasitoid’s symbiotic virus to immunosuppress the host insect, resulting in thermal mismatch and death of the parasitoid. At the transcriptomic level, key viral genes involved in suppressing host immune pathways showed reduced expression, driven by the virus’s circular genomic structure. This work is among the first to demonstrate the genetic and physiological mechanisms by which a symbiont limits the ecological functioning of host-parasite dynamics, and provides a framework for understanding how molecular processes give rise to ecological outcomes in response to high temperature events caused by climate change.
Project description:Parasitoid wasps inject venom containing complex bioactive compounds to regulate the immune response and development of host arthropods and sometime paralyze host arthropods. Although extensive studies have been conducted on the identification of venom proteins in larval parasitoids, relatively few studies have examined the pupal parasitoids. Hereby, proteomic method was used to identify putative venom proteins from P. vindemmiae, an ectoparasitoid of Drosophila.
Project description:Seasonal photoperiodic changes have strong impact on development in Nasonia vitripennis. Here, Using high-throughput Reduced Representation Bisulfite Sequencing (RRBS) and single-molecule-based sequencing, we generated DNA methylation maps of female wasps maintained in long vs short day. We have identified differential methylated loci that encode the photoperiodic change. analysis of DNA methylation in female wasps maintained in long vs short day, using RRBS followed by Illumina sequencing