Project description:Female honeybees are specified as workers or queens based on diet during early development. Workers are essentially sterile with a reduced number of ovarioles and no spermatheca. In the presence of the queen (queen mandibular pheromone) and her brood, worker ovaries are kept in an inactive quiescent state. If the queen is removed, or lost, worker bees are able to sense this change in their environment and their ovaries undergo complete remodeling producing unfertilized haploid eggs that will produce male (drone bees). In this study we analyze gene expression in queen, worker, and laying worker ovaries using RNA-seq and explore differences in the chromatin landscape (focusing on H3K27me3).
Project description:Female honeybees are specified as workers or queens based on diet during early development. Workers are essentially sterile with a reduced number of ovarioles and no spermatheca. In the presence of the queen (queen mandibular pheromone) and her brood, worker ovaries are kept in an inactive quiescent state. If the queen is removed, or lost, worker bees are able to sense this change in their environment and their ovaries undergo complete remodelling producing unfertilised haploid eggs that will produce male (drone bees). In this study we analyse gene expression in queen, worker, and laying worker ovaries using RNA-seq and explore differences in the chromatin landscape (focussing on H3K27me3).
Project description:Transcriptional profiling of brain tissue of was performed by RNA-SEQ in females and males. The sex specific expressed and spliced genes were examined comparing drone and worker honeybees. Examination of mRNA profiles in heads of male and female honeybees pupae were compared.
Project description:Purpose: Parts of Europe and the United States have witnessed dramatic losses in commercially managed honey bees over the past decade to what is considered an unsustainable extent. The large-scale loss of honey bees has considerable implications for the agricultural economy because honey bees are one of the leading pollinators of numerous crops. Honey bee declines have been associated with several interactive factors. Poor nutrition and viral infection are two environmental stressors that pose heightened dangers to honey bee health. Methods: We used RNA-sequencing to examine how monofloral diets (Rockrose and Chestnut) and Israeli acute paralysis virus inoculation influence gene expression patterns in honey bees. Results: We found a considerable nutritional response, with almost 2,000 transcripts changing with diet quality. The majority of these genes were over-represented for nutrient signaling (insulin resistance) and immune response (Notch signaling and JaK-STAT pathways). Somewhat unexpectedly, the transcriptomic response to viral infection was fairly limited. We only found 43 transcripts to be differentially expressed, some with known immune functions (argonaute-2), transcriptional regulation, and muscle contraction. We created contrasts to determine if any protective mechanisms of good diet were due to direct effects on immune function (resistance) or indirect effects on energy availability (tolerance). A similar number of resistance and tolerance candidate differentially expressed genes were found, suggesting both processes may play significant roles in dietary buffering from pathogen infection. We also compared the virus main effect in our study (polyandrous colonies) to that obtained in a previous study (single-drone colonies) and verified significant overlap in differential expression despite visualization methods showing differences in the noisiness levels between these two datasets. Conclusions: Through transcriptional contrasts and functional enrichment analysis, we add to evidence of feedbacks between diet and disease in honey bees. We also show that comparing results derived from polyandrous colonies (which are typically more natural) and single-drone colonies (which usually yield more signal) may allow researchers to identify transcriptomic patterns in honey bees that are concurrently less artificial and less noisy. Altogether, we hope this work underlines possible merits of using data visualization techniques and multiple datasets when interpreting RNA-sequencing studies.
Project description:Here, we examined the transcriptional and epigenetic (DNA methylation) responses to viral infection in honey bee workers. One-day old worker honey bees were fed solutions containing Israeli Acute Paralysis Virus (IAPV), a virus which causes muscle paralysis and death and has previously been associated with colony loss. Uninfected control and infected, symptomatic bees were collected within 20-24 hours after infection. Worker fat bodies, the primary tissue involved in metabolism, detoxification and immune responses, were collected for analysis. We performed transcriptome- and bisulfite-sequencing of the worker fat bodies to identify genome-wide gene expression and DNA methylation patterns associated with viral infection. There were 753 differentially expressed genes (FDR<0.05) in infected versus control bees, including several genes involved in epigenetic and antiviral pathways. DNA methylation status of 156 genes (FDR<0.1) changed significantly as a result of the infection, including those involved in antiviral responses in humans. There was no significant overlap between the significantly differentially expressed and significantly differentially methylated genes, and indeed, the genomic characteristics of these sets of genes were quite distinct. Our results indicate that honey bees have two distinct molecular pathways, mediated by transcription and methylation, that modulate protein levels and/or function in response to viral infections.
Project description:Transcriptome sequencing has become the main methodology for analyzing the relationship between genes and characteristics of interests, particularly those associated with diseases and economic traits. Because of its functional superiority, commercial royal jelly (RJ) and its production are major areas of focus in the field of apiculture. Multiple lines of evidence have demonstrated that many factors affect RJ output by activating or inhibiting various target genes and signaling pathways to augment their efficient replication. The coding sequences made available by the Honey Bee Genome Sequencing Consortium have permitted a pathway-based approach for investigating the development of the hypopharyngeal glands (HGs). In the present study, 3573941, 3562730, 3551541, 3524453, and 3615558 clean reads were obtained from the HGs of five full-sister honey bee samples using Solexa RNA sequencing technology. These reads were then assembled into 18378, 17785, 17065, 17105, and 17995 unigenes, respectively, and aligned to the DFCI Honey Bee Gene Index database. The differentially expressed genes (DEGs) data were also correlated with detailed morphological data for HGs acini. The results identify areas that warrant further study, including those that can be used to improve honey bee breeding techniques and help ensure stable yields of RJ with high quality traits. The 5 samples at given time (d3, d6, d9, d12, d16 after adult worker bees emergence from the comb) are in the critical stage of the RJ secretion and HGs developments indicated (triggered) the further caste differentiation (worker bees and queen) and task switch (nurse bees and foragers). 30 pooled heads of each samples were
Project description:Here, we examined the transcriptional and epigenetic (DNA methylation) responses to viral infection in honey bee workers. One-day old worker honey bees were fed solutions containing Israeli Acute Paralysis Virus (IAPV), a virus which causes muscle paralysis and death and has previously been associated with colony loss. Uninfected control and infected, symptomatic bees were collected within 20-24 hours after infection. Worker fat bodies, the primary tissue involved in metabolism, detoxification and immune responses, were collected for analysis. We performed transcriptome- and bisulfite-sequencing of the worker fat bodies to identify genome-wide gene expression and DNA methylation patterns associated with viral infection. There were 753 differentially expressed genes (FDR<0.05) in infected versus control bees, including several genes involved in epigenetic and antiviral pathways. DNA methylation status of 156 genes (FDR<0.1) changed significantly as a result of the infection, including those involved in antiviral responses in humans. There was no significant overlap between the significantly differentially expressed and significantly differentially methylated genes, and indeed, the genomic characteristics of these sets of genes were quite distinct. Our results indicate that honey bees have two distinct molecular pathways, mediated by transcription and methylation, that modulate protein levels and/or function in response to viral infections. Examination of epigenomic and transcriptomic antiviral responses to Israeli Acute Paralysis Virus in honey bees
Project description:Previously, we attempted to identify the molecular basis for lateralization in honey bee workers by comparing protein expression between left and right antennae of hygienic bees using mass spectrometry-based quantitative proteomics (PXD005242). We identified 1,845 unique proteins but found no significant differences; therefore, we suggested this may be because of insufficient depth of coverage. To improve proteome coverage, we fractionated the peptides from left and right antennae from 4 highly hygienic colonies and repeated the comparison. Here, we identified 3,114 unique proteins (a 69% improvement), which is among the highest proteome coverage achieved in honey bees. However, we still did not identify significant differences. We also compared the proteomes of antennae that were injected with mock dsRNA, dsRNA targeting OBP18, and uninjected. We found a strong effect of microinjecting alone, but no knockdown of our target.
Project description:Olfaction system plays a fundamental role in mediating insect behavior. Besides, the division of queen, worker and drone, honeybee also exhibit an age-dependent division of labor. Worker bees perform discrete sets of behaviors throughout their lifespan. These behavioral states rely on the sense of the environments and chemical communications via their olfactory system - antennae. However, the olfactory adaption mechanism of workers in these processes of behavioral development is still unclear. In this study, we conducted a comprehensive and quantitative analysis of gene expression in Apis mellifera antenna of newly emerged workers, nurses, foragers, and defenders using RNA-seq. We found that antennae tissues continue to develop after transformation from pupae to adult. Additionally, we identified both developmental and labor-division specific expressed genes. We validated the unexpected discovery of major royal jelly protein genes, which are highly and specifically expressed in nurse honeybee workers. We further identified and validated that significant alternative splicing events are also involved in the development and division of labor. These findings provided a comprehensive transcriptome profile and new perspective into the molecular mechanism underlying honeybee division of labor.