Location: Bee Research LaboratoryTitle: RNA-seq reveals disruption in honey bee gene regulation when caged and deprived of hive conditions
|KARIM, SHAHID - University Of Southern Mississippi|
|LAMOUR, KURT - University Of Tennessee|
|STEWARD, SCOTT - University Of Tennessee|
Submitted to: Journal of Experimental Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/26/2019
Publication Date: 9/18/2019
Citation: Alburaki, M., Karim, S., Lamour, K., Adamczyk Jr, J.J., Steward, S. 2019. RNA-seq reveals disruption in honey bee gene regulation when caged and deprived of hive conditions. Journal of Experimental Biology. https://doi.org/10.1242/jeb.207761.
Interpretive Summary: In this study, we present phenotypic and genetic data characterizing the impact of Imidacloprid and caging stress on honey bee Apis mellifera physiological responses and regulation of 45 genes using targeted-RNA seq. The term (caging stress) characterizes the effects resulting from depriving honey bees of all hive aspects and conditions. Two cohorts of one-day-old sister bees were subjected to different conditions. One cohort was caged and fed different imidacloprid-tainted sugar solutions and the second was marked and introduced back to its natal hive. Physiological bee parameters and diet behavior were monitored daily for caged bees over weeks. Bee samples from both cohorts were sampled weekly for RNA sequencing and oxidative stress analyses. Imidacloprid induced significant protein damage and post-ingestive aversion responses in caged bees leading to lower tainted syrup consumption and higher water intake compared to the controls. No differentially expressed genes were observed among caged bees in regards to imidacloprid treatment. However, significant upregulation in antioxidant genes was recorded in caged bees as compared to hive bees, with overwhelming downregulation in all gene categories in caged bees at week 4. We identified 2 sets of genes constantly regulated in caged bees, including Rsod with unknown function in insects that could potentially characterize caging stress in honey bees. The results of this study will help determine the impacts of different imidacloprid concentrations on honey bee physiological traits and genetic responses. Results also allow to understand the potential challenges with cage studies for studying honey bee health.
Technical Abstract: Honey bees caged for experimental purpose show significant alteration in their gene regulation and oxidative stress compared to their sister-mates operating under natural hive conditions. We identified 8 genes that were constantly regulated in caged bees over a 4-week-period compared to their sister-mates marked and put back in their natal hive. Among those gene is Rsod; an uncharacterized gene in insects with unknown function. These genes could potentially characterize the caging stress in honey bees.