Brain transcriptomics of honey bee parasitized by Varroa destructor or Nosema ceranae
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ABSTRACT: In this study we addressed whether the transcriptome profile in the honey bee brain is similar for two major parasites of honey bee, Varroa destructor and Nosema ceranae. Honey bees parasitized by these two parasites show accelerated behavioral maturation and deficiences in orientation and learning/memory that we hoped to characterized at the transcriptomic level. honey bee adults infested by Varroa destructor or Nosema ceranae compared to control bees, in duplicate
Project description:In this study we addressed whether the transcriptome profile in the honey bee brain is similar for two major parasites of honey bee, Varroa destructor and Nosema ceranae. Honey bees parasitized by these two parasites show accelerated behavioral maturation and deficiences in orientation and learning/memory that we hoped to characterized at the transcriptomic level.
Project description:Experimental infection of (2 days old) adult honey bee workers (30 bees per replicates, 3 replicates per treatments, from 3 different colonies (one colony per cage for each treatment)) with 10^9 genome equivalent of Black Queen Cell Virus (BQCV) in 10µl of sugar solution and/or 10^5 fresh Nosema ceranae spores (control bees were given a similar bee extract in PBS, without pathogen). Bees were kept in cages of 30 bees in incubator (30°C/50%RH). At day 13 p.i., bees were flash frozen, and stored at -80°C. Brain mRNA profiles of 15 old bees were generated by deep sequencing, in triplicates except for bees infected by both Nosema ceranae and Black Queen Cell Virus (duplicates)
Project description:We studied the molecular mechanisms underlying the impact of pollen nutrients on honey bee (Apis mellifera) health and how those nutrients improve resistance to parasites. Using digital gene expression, we determined the changes in gene expression induced by pollen intake in worker bees parasitized or not by the mites Varroa destructor, known for suppressing immunity and decreasing lifespan of bees. bees with or without verroa, and fed or not fed pollen
Project description:The microsporidia Nosema ceranae are intracellular parasites that proliferate in the midgut epithelial cells of honey bees (Apis mellifera). To analyze the pathological effects of those microsporidia, we orally infected honey bee workers 7 days after their emergence. Bees were flash frozen 15 days after the infection. Then, the effects on the gut ventriculi were analyzed and compared to non-infected (control) bees. Comparisons of control vs Nosema ceranae bees
Project description:Experiment was designed to study the effect of Deformed wing virus (DWV) and the mite Varroa destructor on on siRNA and miRNA composition using high-throughput sequencing of small RNA in developing worker honeybee (Apis mellifera). Newly hatched bee larvae (day 3 of bee development) were transferred from a Varroa-free colony with low DWV levels to a Varroa-infested colony with high levels of DWV in bees and Varroa mites. All transferred larvae were receiving the DWV strains present in this Varroa-infested colony with the food delivered by the nurse bees until their capping (day 8). About half of these larvae were capped with Varroa mite and were subjected to the mite piercing and feeding on their haemolymph during pupal development until sampling at purple eye stage (day 14). Exposure to the mite piercing and feeding resulted in about 1000-fold increase of the DWV levels in the majority of the mite-exposed pupae compared to the control pupae and the pupae not exposed to Varroa mites.
Project description:Experiment was designed to study the effect of Deformed wing virus (DWV) and the mite Varroa destructor on global gene expression using microarray transcriptional profiling in developing worker honeybee (Apis mellifera). Newly hatched bee larvae (day 3 of bee development) were transferred from a Varroa-free colony with low DWV levels to a Varroa-infested colony with high levels of DWV in bees and Varroa mites. All transferred larvae were receiving the DWV strains present in this Varroa-infested colony with the food delivered by the nurse bees until their capping (day 8). About half of these larvae were capped with Varroa mite and were subjected to the mite piercing and feeding on their haemolymph during pupal development until sampling at purple eye stage (day 14). Exposure to the mite piercing and feeding resulted in about 1000-fold increase of the DWV levels in the majority of the mite-exposed pupae compared to the control pupae and the pupae not exposed to Varroa mites.
Project description:Experiment was designed (i) to analyse the strain composition of Deformed wing virus (DWV) populations in covertly and overtly infected honeybees (Apis mellifera) from Varroa-free and Varroa-infested colonies, and (ii) to determine abundance of the DWV strains following direct injection of the DWV preparations from covertly and overtly infected bees to the bee pupae haemolymph in the absence of Varroa destructor mites. Experiment included isolation of DWV preparations from the following bees: covertly-infected bees from Varroa-free colony, covertly infected bees exposed orally to the Varroa-selected DWV strains, and the overtly infected Varroa-exposed bees. Honeybee pupae were experimentally injected with those DWV preparations and sampled 4 days post injection following development of overt DWV infection. A series of the DWV cDNA fragment covering complete DWV genomic RNA sequences were amplified by RT-PCR using RNA extracted from virus preparations and the injected pupae. The cDNA preparations were sequenced using next generation(Illumina HighSeq 2000) paired-end sequencing to obtain data on the DWV strain composition.
Project description:Extensive annual losses of honey bees (Apis mellifera L.) represent a global problem for agriculture and biodiversity. The parasitic mite Varroa destructor in association with viral co-infections plays a key role in this phenomenon; however, the precise mechanisms are still unclear. We employed a unique combination of transcriptomic, proteomic, metabolomic, and functional analyses to elucidate the effects of Varroa parasitisation. We focused on complex differences between parasitised and unparasitised ten-days old honey bee workers collected from identical colonies before overwintering. Honey bees exposed to mite parasitation during their development revealed alterations in transcriptome and proteome related to immunity, oxidative stress, olfactory recognition, metabolism of sphingolipids and RNA regulatory mechanisms. Specifically, immune reactions and sphingolipids metabolism were strongly up-regulated in parasitised honey bees; whereas olfactory recognition and oxidative stress pathways were down-regulated compared to unparasitised bees. Additionally, the metabolomic analysis confirmed the depletion of nutrients, decreased energy stores and generally disrupted metabolism of parasitised workers, as previously reported. By virtue of comprehensive omics-based analysis, we define the key changes in the honey bee facing Varroa parasitism and suggest possible mechanisms underlying its detrimental effects. This study provides a theoretical basis for future efforts in efficient control strategies against Varroa mites.
Project description:The microsporidia Nosema ceranae are intracellular parasites that proliferate in the midgut epithelial cells of honey bees (Apis mellifera). To analyze the pathological effects of those microsporidia, we orally infected honey bee workers 7 days after their emergence. Bees were flash frozen 15 days after the infection. Then, the effects on the gut ventriculi were analyzed and compared to non-infected (control) bees.