Project description:Background: Honey bee is a major insect used for pollination of a number of commercial crops worldwide. However, the number of managed honey bee colonies has recently declined in several countries, and a number of possible causes are proposed. Although the use of honey bees for pollination can be considered as disruption of the habitat, its effects on honey bees' physiology have never been addressed. In Japan, more than 100 thousands colonies are annually used for pollination, and intriguingly 80% of them are used in greenhouses. Recently, honey bee colonies have often collapsed when they are introduced into greenhouses. Thus, to suppress colony collapses and maintain the number of worker bees in the colonies are essential for successful long-term pollination in greenhouses and recycling honey bee colonies.
Project description:Background: Honey bee is a major insect used for pollination of a number of commercial crops worldwide. However, the number of managed honey bee colonies has recently declined in several countries, and a number of possible causes are proposed. Although the use of honey bees for pollination can be considered as disruption of the habitat, its effects on honey bees' physiology have never been addressed. In Japan, more than 100 thousands colonies are annually used for pollination, and intriguingly 80% of them are used in greenhouses. Recently, honey bee colonies have often collapsed when they are introduced into greenhouses. Thus, to suppress colony collapses and maintain the number of worker bees in the colonies are essential for successful long-term pollination in greenhouses and recycling honey bee colonies. Honey bee hives were installed into strawberry and eggplant greenhouses, and then the gene expression profiles of the honey bees were examined at the different time periods. Total 16 samples with two replicates were analyzed.
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.