Project description:A striking property of the ancient and obligate mutualism between figs and their pollinating wasps is that fig wasps consistently oviposit in the inner flowers of the fig syconium (gall flowers, which develop into galls that house developing larvae), but typically do not use the outer ring of flowers (seed flowers, which develop into seeds). To better understand differences between gall and seed flowers that might influence oviposition choices, and the unknown mechanisms underlying gall formation, we used a metatranscriptomic approach to analyze eukaryotic gene expression within fig flowers at the time of oviposition choice and early gall development. Consistent with the unbeatable seed hypothesis, which posits that only a portion of fig flowers are physiologically capable of responding to gall induction or supporting larval development, we found significant differences in gene expression assigned to defense and metabolism between gall- and seed flowers in receptive syconia. Transcripts assigned to flavonoids and defense were especially prevalent in receptive gall flowers, and carbohydrate metabolism was significantly up-regulated relative to seed flowers. In turn, high expression of the venom gene icarapin during wasp embryogenesis within galled flowers distinguishes it as a candidate gene for gall initiation. In response to galling, the fig significantly up-regulates the expression of chalcone synthase, which previously has been connected to gall formation in other plants. This study simultaneously evaluates the gene expression profile of both mutualistic partners in a plant-insect mutualism and provides evidence for a stability mechanism in the ancient fig-fig wasp association.
Project description:A striking property of the ancient and obligate mutualism between figs and their pollinating wasps is that fig wasps consistently oviposit in the inner flowers of the fig syconium (gall flowers, which develop into galls that house developing larvae), but typically do not use the outer ring of flowers (seed flowers, which develop into seeds). To better understand differences between gall and seed flowers that might influence oviposition choices, and the unknown mechanisms underlying gall formation, we used a metatranscriptomic approach to analyze eukaryotic gene expression within fig flowers at the time of oviposition choice and early gall development. Consistent with the unbeatable seed hypothesis, which posits that only a portion of fig flowers are physiologically capable of responding to gall induction or supporting larval development, we found significant differences in gene expression assigned to defense and metabolism between gall- and seed flowers in receptive syconia. Transcripts assigned to flavonoids and defense were especially prevalent in receptive gall flowers, and carbohydrate metabolism was significantly up-regulated relative to seed flowers. In turn, high expression of the venom gene icarapin during wasp embryogenesis within galled flowers distinguishes it as a candidate gene for gall initiation. In response to galling, the fig significantly up-regulates the expression of chalcone synthase, which previously has been connected to gall formation in other plants. This study simultaneously evaluates the gene expression profile of both mutualistic partners in a plant-insect mutualism and provides evidence for a stability mechanism in the ancient fig-fig wasp association. We examined two different Ficus flower types at two different time points. Each sample contained a pool of hundreds of individual flowers from multiple sycomia.
Project description:Upon pathogenic infection, drosophila larval host mounts an immune response. Parasitic wasps inject venom that contain virulence factors during oviposition, which can elicit host immune response, and in some cases, suppress host immune responses altogether. Several microarray experiments have been performed on different classes of parasitic wasps. We wanted to compare how Ganaspis xanthopoda-infected hosts respond compared to other classes of parasitic wasps.
2010-11-23 | GSE25522 | GEO
Project description:partial genomic scaffold of fig wasps
Project description:Upon pathogenic infection, drosophila larval host mounts an immune response. Parasitic wasps inject venom that contain virulence factors during oviposition, which can elicit host immune response, and in some cases, suppress host immune responses altogether. Several microarray experiments have been performed on different classes of parasitic wasps. We wanted to compare how Ganaspis xanthopoda-infected hosts respond compared to other classes of parasitic wasps. Third instar y w larvae from a 2-day egglay were infected with G. xanthopoda for three and six hours, respectively, by introducing waps in petri-dish containing larvae. Controls were handled side-by-side without introducing wasps. Host larvae were immediately dissected, infection confirmed by presence of wasp egg, and frozen in liquid nitrogen and ground in Trizol. RNA was isolated and checked by agarose gel-electrophoresis. Samples were then sent to the Microarray Core Facility at Weill Cornell Medical College.
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: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