MIG Seminar – Emily Remnant – 20th April, 2018

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Andrew Siebel

asiebel@unimelb.edu.au

T: +61 3 8344 0707

Emily Remnant

The University of Sydney

Friday 20th April
12-1pm
FW Jones Theatre, Medical Building, The University of Melbourne

Plight of the humble bee: The virome of honey bee populations exposed to an ectoparasitic mite.

Abstract
Understanding viral diversity in bees is critical for maintaining pollinator health and managing the spread of disease. The viral landscape of honey bees (Apis mellifera) has changed since the emergence of the ectoparasitic mite, Varroa destructor. The worldwide spread of Varroa caused decreased honey bee health due to the viruses that Varroa harbours and transmits to bees upon feeding. Current strategies to prevent honey bee declines rely on managing Varroa levels with chemicals, or breeding Varroa-resistant bees. A number of Varroa-resistant honey bee populations exist that survive mite infestations without chemical intervention. If honey bee deaths are due to particular viruses, we would expect Varroa-resistant bee populations to exhibit different viral landscapes compared to sensitive bees.

In this talk I will present three key findings from a study where we used viral metagenomics to compare Varroa-resistant and susceptible honey bee populations from diverse locations around the world. First, we observe new strains of the highly pathogenic Deformed Wing Virus (DWV) in some populations that are resistant to Varroa, while in other isolated populations, DWV levels remain low or absent despite the presence of Varroa. Second, we describe seven completely new viruses, including the first examples of honey bee viruses belonging to the negative-sense ssRNA class. Finally, we examine the RNA interference (RNAi) pathway, a major antiviral immune pathway in insects, and identify a novel and distinct viral small RNA profile in Varroa mites compared to bees, indicating that viruses are processed differently between bees and their mite parasites.

I will discuss these results in the context of my current research, identifying novel avenues that may be exploited in Varroa biocontrol, and investigating the use of the bacterial endosymbiont Wolbachia as a viral protection mechanism for honeybee populations suffering from virulent viruses.

Bio
Emily studies the genetics and genomics of insects, to understand evolutionary processes and explore ways to improve the health of beneficial insects like honey bees. Emily completed her PhD at the University of Melbourne in 2012, using Drosophila melanogaster to investigate the genetic changes involved in the development of insecticide resistance. She joined the University of Sydney as a postdoctoral researcher in 2012. Earlier this year Emily was appointed as an Early Career Development Fellow and lecturer. Her current research focuses on host-parasite interactions, investigating new ways to protect honey bees against viral disease, and understanding epigenetic processes involved in the evolution of eusociality.

Enquiries: Andrew Siebel (asiebel@unimelb.edu.au)