Project description:Plant pollination by the western honey bee Apis mellifera is an irreplaceable agroecological and economic cornerstone currently under threat. Recent colony loss has been consistently linked to the increased prevalence of deformed wing virus (DWV), an Iflavirus transmitted from the ecoparasitic mite Varros destructor. While DWV has been detected in the honey bee brain and causally linked to behavioral impairment, the molecular impact of infection on brain gene expression is largely unknown. Recently, we discovered that two published and two new brain transcriptomic studies conducted in our lab contained DWV contamination in over 99% of sequenced honey bee samples. This unanticipated finding sharply contrasted with the experimental paradigms of these four studies, as no physical or behavioral signs of DWV were detected in any of the 335 individual honey bees sampled. We took this opportunity to perform a meta-analysis and test the hypothesis that DWV influences brain gene expression, a relationship which could be linked to the massive depopulation events observed around the world. Results from our study support commonalities in the molecular consequences of DWV in the honey bee brain and implicate specific genes and biological processes associated with infection. Next, we used single-cell RNA-Sequencing to implicate glia as active responders to viral infection. Finally, we performed viral gene expression analysis on a subset of samples and found DWV type A as well as a previously unreported A-B recombinant in the brain. We present this meta-analysis as a first step toward addressing a potential missing link between viral infection and behavior in honey bees.
2020-02-04 | GSE130785 | GEO
Project description:RNA-Seq of deformed wing virus (DWV) infection on honey bee larvae
Project description:Varroa destructor is one of the most prevalent and economically damaging honey bee pests worldwide, weakening colonies by simultaneously parasitizing and transmitting damaging viruses. Despite these impacts on honey bee health, surprisingly little is known about its fundamental molecular biology. Here we present a high-resolution V. destructor protein atlas crossing all major developmental stages (egg, protonymph, deutonymph and adult) for both male and female mites as a web-based interactive tool. In a proteogenomic effort, we identified 1,464 unique peptides corresponding to 419 proteins which were previously unannotated and we included these in all subsequent analyses. In order to use mass spectrometry-based peptide sequencing to augment the genome annotation of non-model species, we analyzed their amino acid and nucleotide composition as well as orthology to other species to suggest reasons why they may have been missed initially. Using label-free quantitative proteomics, we found that 1,433 proteins were differentially regulated across developmental stages, including proteins belonging to deformed wing virus and V. destructor virus. One other virus – the bee macula-like virus – was also detected, along with the protein generated by its short 3’ overlapping reading frame. In addition, we found that 101 proteins are sexually regulated and functional enrichment analysis suggests how they may contribute to sex-specific phenotypes and behaviour. Overall, this work provides a first of its kind interrogation of the patterns of gene expression that govern the Varroa life cycle and the tools we have developed will support further research on this threatening honey bee pest.
2017-09-06 | PXD006072 | Pride
Project description:Transcriptomic Responses of the Honey Bee Brain to Infection with Deformed Wing Virus
Project description:Understanding the biological mechanisms underlying extreme lifespan variation within species remains a fundamental challenge in aging research. Here, we investigated the role of gut microbiota and age in honey bee (Apis mellifera) queens combining metagenomics and transcriptomics. Analysis of 40 queen hindguts revealed that Commensalibacter melissae (Alpha 2.1) relative abundance was significantly higher in young queens compared to old queens. Using queens with the highest and lowest C. melissae relative abundance, RNA sequencing identified 1,451 differentially expressed genes associated with C. melissae abundance, twice the number associated with age alone (719 genes). Queens with high C. melissae abundance showed distinct transcriptional profiles related to stress response, protein homeostasis, and longevity-regulating pathways, particularly genes involved in oxidative stress response and cellular maintenance. Our analysis revealed complex relationships between age, C. melissae abundance, and gene expression patterns, suggesting that multiple interacting factors contribute to queen quality. These findings contribute to our understanding of host-microbe interactions in honey bee queens and highlight the intricate relationship between gut microbiota composition and host physiology in honey bees.
Project description:Exoproteome represents the proteome consisting of all secreted proteins and proteins derived from the cell surface and lysed cell. The exoproteome of the trypanosomatid parasite should interact with the host cells and the associated microbiota; however, the roles of infecting insect hosts are not yet understood. To uncover the functions of exoproteome, we identified the exoproteome of honey bee trypanosomatid parasite, Lotmaria passim, and found that approximately 28 % are shared with that common between Leishmania spp. It demonstrates a core exoproteome with conserved functions exists in the Leishmaniinae lineage. The bioinformatic characterization suggests that L.passim exoproteome may interact with the host and its microbiota as well as their metabolites. Deletion of genes encoding two secretome proteins revealed that an aspartyl protease but not chitinase affects the development of L. passim under the culture condition and is necessary for the efficient infection in the honey bee gut. Our results demonstrate that the exoproteome represents a resource to uncover the mechanisms of trypanosomatid parasites to infect the insect host by interacting with the gut environment.