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: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.
2016-09-06 | GSE81664 | GEO
Project description:Complete genome sequence of Deformed Wing Virus and Black Queen Cell Virus isolated from Honey bees in Argentina
Project description:Effects of behavioral maturation, diet quality and Queen Mandibular Pheromone on gene expression in the abdominal fat bodies of worker honey bees.
Project description:Flenniken - Honey bee gene expression microarray experimental design<br>To minimize variability between samples all arrayed bees were obtained from a single brood comb from a naturally mated queen, therefore all the bees were age-matched half-sisters. The bees selected for microarray analysis of virus (Sindbis-eGFP) co-injected with either virus-specific-dsRNA (vs-dsRNA) or non-specific dsRNA (ns-dsRNA) exhibited the reduced virus phenotype that was seen in the majority of the bees assayed. The five representative bees from each condition (v, v+vs-dsRNA, v+ns-dsRNA, dsRNA, and mock/injected with buffer) selected for microarray analysis were free of pre-existing conditions (assessed by APM analysis) (Runckel, Flenniken et al., 2011). To facilitate gene expression comparisons between multiple treatment groups we utilized a reference-design strategy in which each Cy5-labeled experimental sample was hybridized with a standardized Cy3-labeled reference sample. A complex RNA mixture representing hundreds of bees of various ages exposed to difference treatment groups, served as the reference RNA sample.
Project description:Expression profiling of honey bee brains exposed to queen mandibular pheromone. Exposure was performed in cages for 3 and 4 days; 3 and 4 days-old bees were analyzed
Project description:In honey bees (Apis mellifera), the reproductive queen produces a pheromonal signal that regulates many aspects of worker behavior and physiology and is critical for maintaining colony organization. Queen mandibular pheromone (QMP) inhibits worker reproduction, attracts workers from a short distance (retinue response), inhibits the rearing of new queens, modulates age-related division of labor and globally alters brain gene expression in worker bees. Interestingly, substantial variation in worker retinue responses to QMP has been found between colonies, but the molecular and physiological bases for variation in individual responses to the queen have not been characterized. Here, we demonstrate that individual retinue response is negatively correlated with traits associated with reproductive potential. Workers with low response to QMP have more ovarioles and higher levels of vitellogenin transcripts than workers with a high response to QMP, suggesting that workers with greater reproductive potential may be attempting to escape queen control. Retinue response appears to be associated with a suite of behavioral and physiological traits that may be pleiotropically linked. However, while these phenotypes are all correlated at the organismal level, the underlying brain expression patterns and gene networks associated with each trait are independent, suggesting that these phenotypes are uncoupled at the molecular level in adult bees. These studies provide insights into the ultimate and proximate causes of natural variation in pheromone response in honey bees.
Project description:There were important gaps in our knowledge of Israeli acute paralysis virus (IAPV), when IAPV was tightly linked to bee Colony Collapse Disorder (CCD), the mysterious disease that, starting in 2006-2007, has been wiping out honey bees in the US. To fill in these gaps we studied the molecular basis of transmission, pathogenesis, and genetic diversity of IAPV infection in honey bees. We investigated the impact of IAPV infection on colony losses and host transcriptional response to IAPV infections, and exploited the potential of RNAi-based strategies for treating viral diseases in honey bees. Our study clearly shows that IAPV has become established as a persistent infection and is highly prevalent in the honey bee population. The existence of both horizontal and vertical transmission pathways of the virus likely accounts for the high prevalence of IAPV in bees. While IAPV is probably not the only culprit responsible for CCD, its ability to cause increased mortality in honey bees is firmly demonstrated. The phenotypic differences in pathology among different strains of IAPV may be due to their high level of standing genetic variation. The JAK-STAT pathway, along with other signaling events such as mTOR and MAPK pathways, likely involves honey bees’ antiviral immune responses to the IAPV infection. The identification of IAPV-encoded putative suppressor of RNAi and evidence that silencing the RNAi suppressor led to a significant reduction in IAPV replication in infected bees illustrates the therapeutic potential of targeting viral suppressor protein to reduce virus replication. Our study gives direction for developing strategies to reduce colony losses due to viral diseases.
Project description:Responses to social cues, such as pheromones, can be modified by genotype, physiology, or environmental context. Honey bee queens produce a pheromone (queen mandibular pheromone; QMP) which regulates many aspects of worker bee behavior and physiology. Forager honey bees are less responsive to QMP than young nurse bees engaged in brood care, suggesting that physiological changes associated with behavioral maturation may modulate response to this pheromone. Since cGMP is a major regulator of behavioral maturation in honey bee workers, we examined its role in modulating worker responses to QMP. Treatment with a cGMP analog, 8-Br-cGMP, resulted in significant reductions in both behavioral and physiological responses to QMP in young caged workers. Treatment significantly reduced attraction to QMP (the retinue response) and inhibited the QMP-mediated increase in vitellogenin levels in the fat bodies of worker bees. Genome-wide analysis of brain gene expression patterns demonstrated that cGMP has a larger effect on expression levels than QMP, and that QMP has specific effects in the presence of cGMP, suggesting that some responses to QMP may be dependent on an individual beesM-^R physiological state. Several functional gene categories were significantly differentially expressed, including genes involved in regulating GTPase activity, phototransduction, immunity, and carboxylic acid transmembrane transporter activity. Overall, our data suggest that cGMP-mediated processes play a large role in modulating responses to queen pheromone in honey bees, at the behavioral, physiological and molecular levels.
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).