Location: Bee Research LaboratoryTitle: Host-parasite interactions and purifying selection in a microsporidian parasite of honey bees Author
Submitted to: PLoS One
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/5/2016
Publication Date: 2/3/2016
Citation: Huang, Q., Chen, Y., Wang, R., Cheng, S., Evans, J.D. 2016. Host-parasite interactions and purifying selection in a microsporidian parasite of honey bees. PLoS One. 11(2): e0147549. Interpretive Summary: Honey bees face disease from many parasites and pathogens, leading to honey bee declines and losses. One gut parasite, Nosema, has negative effects on honey bee nutrition and longevity. Here we have conducted an extensive survey of bee responses to this parasite, showing two key immune responses by bees. These responses are countered in part by the parasite. It is anticipated that these insights might improve efforts to breed resistant honey bees.
Technical Abstract: Nosema ceranae is a microsporidian parasite that infects honey bee mid-gut epithelial cells. Infection can impair honey bee cognitive function, shorten lifespan, suppress the innate immune response and inhibit the apoptosis of infected gut cells. However, the virulence factors of this parasite are still unclear. Previously, we identified a protein in the RNAi pathway, Aubergine that may be involved in reducing N. ceranae levels. In order to further understand the mechanisms used by this parasite to regulate host gene expression, we analyzed the transcriptomic profiles of both honey bee hosts andN. ceranae parasites at 24 hour intervals for 6 days post infection, covering a complete infection cycle. We found that the host gene putatively encoding Aubergine was significantly suppressed during the entire infection period, while the parasite gene for the RNAi protein Agronaute was highly expressed during the entire infection period. Also, the parasite gene encoding an inhibitor of apoptosis was expressed as early as day two post infection. A host serine/threonine-protein which may phosphorylate the pro-apoptosis bcl-2 family protein to protect the mitochondrial membrane integrity against apoptosis was significantly over expressed for all six days post infection. N. ceranae shows signs of suppressing apoptosis of infected cells and of engaging the RNAi system of the host to complete its own reproduction.