We found that insects infected with a very common bacterial endosymbiont
(Wolbachia) are protected from pathogenic viruses. This finding is
both unexpected and has the potential to influence the outcome of
host-pathogen interactions in a number of ways.
I think our paper is highly cited because it has led to several new
directions for research in understanding the mechanism of this
symbiont-mediated protection, the impact on Wolbachia and virus
ecology, and the importance of this protection on the transmission of
pathogens by insect vectors.
Does it describe a new discovery, methodology, or
synthesis of knowledge?
A fly (Drosophila melanogaster) on the end of an injection
This paper describes a new discovery. Interestingly, in independent
research, Luis Teixeira of the Department of Genetics, University of
Cambridge found similar results to ours, which were also published in 2008.
Would you summarize the significance of your paper
in layman's terms?
Many human, animal, and plant viruses are transmitted between hosts by
Understanding the processes that control virus infection in insects may
facilitate strategies that aim to control the spread of important viral
There are also insects that are beneficial both to our environment and
agriculture, for example, honeybees are important pollinators of plants.
Controlling the pathogenic viruses that infect them could protect these
Our paper identified a naturally occurring novel way to interfere with the
virus infection cycle in insects.
How did you become involved in this research, and
were there any problems along the way?
We set out to understand the biological mechanisms used in insects to
reduce susceptibility to virus infection. To examine this question a
student in my lab, Lauren M. Hegdes, looked at virus infection in the model
organism, Drosophila melanogaster.
The finding that Wolbachia is a major contributing factor to
antiviral defense in flies was unexpected. It took us some time to realize
that the antiviral affect we were seeing was not controlled by the host as
we had expected, but was dependent on the Wolbachia infection
status of the host.
Where do you see your research leading in the
We are currently investigating the mechanisms that lead to
symbiont-mediated antiviral protection and are collaborating with
theoretical ecologists to look at the impact this protection would have on
the ecology of microbes in natural insect populations.
Do you foresee any social or political
implications for your research?
If symbiont-mediated protection can be harnessed to decrease
insect-vectored pathogen transmission this could indeed have important
Dr. Karyn Johnson
School of Biological Sciences
University of Queensland
St Lucia, Australia Web