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.
Project description:Our molecular understanding of honey bee cellular stress responses is incomplete. Previously, we sought to identify and began functional characterization of the components of the UPR in honey bees. We observed that UPR stimulation resulted in induction of target genes upon and IRE1 pathway activation, as assessed by splicing of Xbp1 mRNA. However, were not able to determine the relative role of the various UPR pathways in gene activation. Our understanding of honey bee signal transduction and transcriptional regulation has been hampered by a lack of tools. After using RNAseq to expand the known UPR targets in the bee, we use the Drosophila melanogaster S2 cell line and honey bee trans and cis elements to investigate the role of the IRE-1 pathway in the transcriptional activation of one of these targets, the honey bee Hsc70-3 gene. Using a luciferase reporter, we show that honey bee hsc70 promoter activity is inducible by UPR activation. In addition, we show that this activation is IRE1-dependent and relies on specific cis regulatory elements. Experiments using exogenous honey bee or fruit fly XBP1S proteins demonstrate that both factors can activate the Hsc70-3 promoter and further support a role for the IRE-1 pathway in control of its expression in the honey bee. By providing foundational knowledge about the UPR in the honey bee and demonstrating the usefulness of a heterologous cell line for molecular characterization of honey bee pathways, this work stands to improve our understanding of this critical species.
Project description:Social caste determination in the honey bee is assumed to be determined by the dietary status of the young larvae and translated into physiological and epigenetic changes through nutrient-sensing pathways. We have employed microRNA gene-microarray, and observed that both worker jelly and royal jelly showed dynamic changes in miRNA content during the 4th to 6th day of larval development . Adding specific miRNAs to royal jelly elicited significant changes in queen larval mRNA expression and in morphological characters of the emerging adult queen bee. We propose that miRNAs in the nurse bee secretions constitute an additional element in the regulatory control of caste determination in the honey bee.
Project description:Social caste determination in the honey bee is assumed to be determined by the dietary status of the young larvae and translated into physiological and epigenetic changes through nutrient-sensing pathways. We have employed Illumina/Solexa sequencing to examine the small RNA content in the bee larval food source, and show that worker jelly is enriched in miRNA complexity and abundance relative to royal jelly. The miRNA levels in worker jelly were 7-215 fold higher than in royal jelly, and both jellies showed dynamic changes in miRNA content during the 4th to 6th day of larval development. Adding specific miRNAs to royal jelly elicited significant changes in queen larval mRNA expression and in morphological characters of the emerging adult queen bee. We propose that miRNAs in the nurse bee secretions constitute an additional element in the regulatory control of caste determination in the honey bee.
Project description:Honey bee drones, queens and workers have vastly different phenotypes. Here we profile the the expression level of mRNAs and microRNAs of honeybee, drones, queens and workers at the L5 larval stage (91 hours +/- 1).
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:The present study is the first study to identify the involvement of mRNA, lncRNAs, circRNAs and miRNA in the ovary of honey-bee workers.We predicted 10271 mRNAs, 7235 lncRNAs, 11794 circRNAs and 164 miRNAs in the ovary of honey bee workers.
Project description:Honey bee embryos were injected either with a CRISPR contruct targeting the orco gene or an injection buffer control. RNA-Sequencing was performed on the antennal mRNA from adult bees within 24 hours of eclosion.
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. honey bee adults infested by Varroa destructor or Nosema ceranae compared to control bees, in duplicate