Associate Professor, University of Georgia, Department of Entomology
grburke [at] uga.edu
BS, Microbiology and Genetics, University of Queensland, Australia
PhD, Department of Ecology and Evolutionary Biology, University of Arizona
Postdoctoral Fellow, Department of Entomology, University of Georgia
Hereditary symbiosis is a common mechanism by which eukaryotic hosts can acquire traits beneficial for their fitness. Many insects have symbiotic associations with bacteria that trace back millions of years, whose function and evolution are well characterized. Insects can also possess more recently derived symbionts that are closely related to free-living bacteria, and often play a role in host defense. My dissertation focused upon Serratia symbiotica, a recently derived symbiont that infects aphids and provides protection against heat stress, and possibly also plays a nutritional role. I studied several aspects of the biology of recent symbionts, including the diversity of functional roles and evolution among hosts for single lineages of symbionts, the molecular mechanisms that contribute to defense, the early stages of symbiont genome evolution, and interactions with hosts.
While bacteria are well recognized to form beneficial symbiotic associations with metazoans, viruses are usually viewed as non-living, parasitic entities that interact with hosts in ways that only benefit their own transmission and persistence. Several lineages of parasitoid wasps have viruses that have been associated with their hosts for millions of years, and have evolved to be beneficial for wasps. These Domesticated Endogenous Viruses (DEVs) are essential to the survival of the wasp’s offspring, which depend upon viral gene products that can manipulate host physiology and development and inhibit immune defenses.
My lab has continued to work in the field of bacterial symbiosis by studying the symbionts of sap-sucking insects known as adelgids. We also have several projects that focus upon parasitoid wasp viruses that are described under the Research section of the website.