Jake Russell

Education:

2004	PhD, University of Arizona, Tucson, AZ. Major: Ecology and Evolutionary Biology
1999	BS, University of Rochester, Rochester, NY. Major: Molecular Genetics

Research goals:

Bacteria commonly engage in symbiotic interactions with animals. These intimate, prolonged associations are highly prevalent among the insects, which represent one of the best-studied groups of eukaryotes from a perspective of symbiosis. Many of these symbioses are ancient, specialized, irreversible, and highly coevolved. Others are more labile, having evolved more recently. The consequences of these interactions, both young and ancient, are profound. Several bacteria have enabled their hosts to colonize ecological and dietary niches that were previously unavailable. Others have behaved as selfish manipulators, promoting their own interests at the expense of their hosts. These antagonistic associations are known to alter host reproduction, sex ratios, genome evolution and, quite possibly, diversification. My research is focused on understanding the consequences and evolutionary
histories of symbiosis between bacteria and insects. Through a combination of molecular, phylogenetic, and experimental techniques, I have studied bacterial symbionts in aphids, ants, butterflies, and lice to further our understanding of the patterns and processes that characterize the evolution of species interactions. This research has focused, primarily, on the following questions:

1. How diverse are the bacterial communities of insects?

2. What forces shape the diversity and distributions of bacterial symbionts?

3. Have bacterial symbionts coevolved with their insect hosts? Are they specialized on particular insect taxa?

4. How has symbiosis impacted bacterial evolution?

5. How has symbiosis shaped the ecology and evolution of the insects?

Dissertation research:

I received my Ph.D in 2004 from the University of Arizona, where I worked with Nancy Moran on bacterial symbionts of aphids, a group of economically important crop pests that vector virulent plant pathogens. Symbiosis is ubiquitous within these insects, and nearly all aphids harbor a “primary” bacterial symbiont known as Buchnera aphidicola. Aphids occasionally harbor additional maternally transmitted bacteria known as “secondary” symbionts. These microbes are sporadically distributed across species and are typically found at intermediate frequencies within aphid populations. For my dissertation, I explored the distributions of these bacteria, the evolutionary histories of their symbiotic associations with aphids, and their functional significance from the perspective of their hosts.

My findings revealed that secondary symbionts have evolved multiple times throughout the bacterial phylogeny. Three microbes from the Enterobacteriaceae (Gammaproteobacteria) were especially common in aphids:
“Candidatus Serratia symbiotica”, “Candidatus Hamiltonella defensa”, and “Candidatus Regiella insecticola” (1). These bacteria were found in members of several aphid tribes, with 9-16% of 67 surveyed species testing positive. 16S rRNA phylogenies of symbionts were incongruent with host mtDNA phylogenies, indicating that these bacteria have undergone occasional horizontal transmission between aphid species (2). Crucially, through a combination of microinjection transfers, diagnostic PCR assays, and fitness experiments, I demonstrated that secondary symbionts are capable of persisting within multiple host species, thus revealing their generalist nature (3). I also demonstrated significant phenotypic consequences of symbiont infection. First, I found that both S. symbiotica and H. defensa confer thermotolerance upon their aphid hosts (4). Second, through a collaboration with Kerry Oliver, Martha Hunter, and Nancy Moran, I helped to discover that S. symbiotica and H. defensa augment host resistance to parasitoids (5). These findings reveal novel beneficial strategies for persistence of heritable bacteria within insect populations; they also highlight the importance of the environment in shaping the outcomes of symbiotic interactions.

Postdoctoral research:

I am currently an NSF Postdoctoral Fellow working with Naomi Pierce at Harvard University. I have continued my research on symbiosis between bacteria and arthropods, focusing on the microbial associates of ants, lycaenid
butterflies, and several ectoparasites of birds. The ecological, taxonomic, and geographic breadth of these invertebrate collections has provided me with a fantastic opportunity to study the patterns of symbiosis across a wide range of hosts.

In collaboration with researchers from Harvard University (Benjamin Goldman-Huertas, Corrie Moreau, Naomi Pierce), the University of Rochester (Jack Werren), and the University of California-Riverside (Laura Baldo), I am
conducting a Multi-Locus Sequence Typing study of the reproductive parasite, Wolbachia (Alphaproteobacteria). Wolbachia is the most prevalent heritable bacterium in insects, infecting between 15-75% of species world-wide. Through a series of manipulative strategies, this microbe has had profound impacts on the ecology and evolution of the insects, shaping host development, reproduction, sex ratios, genome evolution, and possibly speciation. Our research has addressed the evolutionary histories of Wolbachia associations with the ants and butterflies, focusing on the following questions:

1. Have related Wolbachia coevolved with particular insect taxa?

2. Are related Wolbachia specialized on related groups of insects?

3. How has geography shaped the histories of Wolbachia-host associations?

4. Are Wolbachia commonly transferred among ecologically interacting species?

I am currently collaborating with Noah Whiteman (Harvard University) on an analogous study of Wolbachia in co-occurring populations of five ectoparasites, including lice, louse-flies and avian skin mites. In our research, we aim to determine the effects of geographic isolation, ecological interactions, and host-association on the evolution of Wolbachia endosymbionts. We will also determine whether Wolbachia genes can be used as population genetic markers for studies on the demographic and evolutionary history of Buteo galapagoensis, the endangered Galápagos hawk.

Finally, in collaboration with Corrie Moreau, Benjamin Goldman-Huertas, and Mikiko Fujiwara (Harvard University), I am conducting a study on the diversity and phylogenetics of bacteria across the ants. Through a combination of
molecular and phylogenetic analyses, I have discovered evidence for bacterial specialization, convergent evolution in bacterial lifestyles, and potential roles for bacteria in promoting convergent dietary evolution among the ants. Our results suggest the importance of host diet and phylogeny in shaping the diversity and composition of bacterial communities. We are currently planning a broader bacterial survey across the ants to determine the ecological, geographic, and evolutionary factors that shape and structure the diversity of bacterial gut communities. Furthermore, we plan to describe the roles of microbes in ant nutrition and dietary ecology. The breadth of this research will allow us to determine the importance of bacteria in the evolution of the most abundant group
of metazoans on the planet.

References cited:

1) Moran NA, Russell JA, Koga R, Fukatsu T (2005) Evolutionary relationships of three new species of Enterobacteriaceae living as symbionts of aphids and other insects. Applied and Environmental Microbiology 71: 3302-3310.

2) Russell JA, Latorre AL, Sabater-Muñoz B, Moya A, Moran NA (2003) Side-stepping secondary symbionts: Widespread horizontal transfer across and beyond the Aphidoidea. Molecular Ecology 12: 1061-1075.

3) Russell JA, Moran NA (2005) Horizontal transfer of bacterial symbionts: heritability and fitness effects in a novel aphid host. Applied and Environmental Microbiology 71: 7987-7994.

4) Russell JA, Moran NA (2006) Costs and benefits of symbiont infection in aphids: variation among symbionts and across temperatures. Proceedings of the Royal Society B – Biology 273: 603-610.

5) Oliver KM, Russell JA, Moran NA, Hunter MS (2003) Facultative bacterial symbionts in aphids confer resistance to parasitic wasps. Proceedings of the National Academy of Sciences of the United States of America 100:
1803-1807.

Honors and awards:

2006	Green Fund
2004	NSF Postdoctoral Fellowship in Microbial Biology
2003	University of Arizona, Ecology and Evolutionary Biology: Hoshaw Award
2003-2004	IGERT Fellowship in Genomics
2002	Center for Insect Science Small Grant
2000-2002	Plant Insect Interaction Group Grant
2001	RTG Small Grant
2000-2003	University of Arizona, Ecology and Evolutionary Biology: Small Grant
1999	University of Arizona Graduate College Fellowship
1999	Magna Cum Laude
1999	Phi Beta Kappa
1998	Golden Key National Honor Society
1998	DeKiewiet Fellowship (University of Rochester)

Teaching experience:

2002	Teaching assistant, University of Arizona, Ecology 335: Evolution
1997	Teaching assistant, University of Rochester, Biology 115: Human Genetics and Evolution

Publications:

Russell JA, Goldman-Huertas B, Moreau CS, Baldo, L, Werren JH, Pierce NE. (in prep.) Host affiliation and geography shape symbiont evolution: A study of Wolbachia in ants and butterflies.

Russell JA, Moreau CS, Goldman-Huertas B, Fujiwara MK, Pierce NE. (in prep.) The evolution and diversity of microbial communities in ants.

Russell JA, Moran NA (2006) Costs and benefits of symbiont infection in aphids: variation among symbionts and across temperatures. Proceedings of the Royal Society B – Biology 273: 603-610. [PDF]

Russell JA, Moran NA (2005) Horizontal transfer of bacterial symbionts: heritability and fitness effects in a novel aphid host. Applied and Environmental Microbiology 71: 7987-7994. [PDF]

Moran NA, Russell JA, Koga R, Fukatsu T (2005) Evolutionary relationships of three new species of Enterobacteriaceae living as symbionts of aphids and other insects. Applied and Environmental Microbiology 71: 3302-3310. [PDF]

Oliver KM, Russell JA, Moran NA, Hunter MS (2003) Facultative bacterial symbionts in aphids confer resistance to parasitic wasps. Proceedings of the National Academy of Sciences of the United States of America 100: 1803-
1807. [PDF]

Russell JA, Latorre AL, Sabater-Muñoz B, Moya A, Moran NA (2003) Side-stepping secondary symbionts: Widespread horizontal transfer across and beyond the Aphidoidea. Molecular Ecology 12: 1061-1075. [PDF]

Sandström J, Russell JA, White JP, Moran NA (2001) Independent origins and horizontal transfer of bacterial symbionts of aphids. Molecular Ecology 10: 217-228. [PDF]

Parsch J, Russell JA, Beerman I, Hartl DL, Stephan W (2000) Deletion of a conserved regulatory element in the Drosophila adh gene leads to increased alcohol dehydrogenase activity but also delays development. Genetics 156: 219-227. [PDF]

Research presentations:

Invited Talks

2006	University of Connecticut, Department of Molecular and Cellular Biology: “Diversity, histories, and significance of symbioses between insects and bacteria”
2005	Society for the Study of Evolution Annual Meeting: "Temperature shapes the costs and benefits of symbioses between aphids and maternally transmitted bacteria"
2005	Fordham University, Department of Biology: "Coevolution and consequences of symbioses between aphids and maternally transmitted bacteria"
2004	Oklahoma State, Department of Entomology and Plant Pathology: "Coevolution and consequences of symbioses between aphids and maternally transmitted bacteria"
2004	Entomological Society of America Annual Meeting: "Conditional fitness effects of maternally transmitted bacteria in the pea aphid, Acyrthosiphon pisum"
2004	University of Arizona, Center for Insect Science, Hexapodium: "Secondary symbionts shape heat tolerance in the pea aphid, Acyrthosiphon pisum"

Additional Talks

2006	Society for the Study of Evolution Annual Meeting: "Do Wolbachia coevolve with their insect hosts?"
2006	Third international Congress on Phthiraptera: “Galápagos Hawks and their chewing lice: A model system for understanding host-parasite ecology and evolution.” (N.K. Whiteman, J.L. Bollmer, K.D. Matson, R.T. Kimball, J.A. Russell, P.G. Parker)
2004	University of Arizona, Department of Ecology and Evolutionary Biology, dissertation defense: "Coevolution and consequences of symbioses between aphids and maternally transmitted bacteria"
2004	University of Arizona, Department of Ecology and Evolutionary Biology, Noon Seminar: "Bacterial symbionts protect pea aphids from the damaging effects of high temperatures"
2003	Society for the Study of Evolution Annual Meeting: "How do the microbial guests of aphids earn their keep? Explaining the distributions of secondary symbionts within and across their host species"
2003	University of Arizona, Department of Ecology and Evolutionary Biology, Noon Seminar: "How do the microbial guests of aphids earn their keep? Explaining the distributions of secondary symbionts within and across their host species"
2002	University of Arizona, Department of Ecology and Evolutionary Biology, Noon Seminar: "Horizontal Transfer: What are the rate-limiting steps for facultative bacterial symbionts of insects?"
2000	University of Arizona, Department of Ecology and Evolutionary Biology, Noon Seminar: "Diverse microbial communities of aphids"

Posters:

2005	Harvard Plant Biology Symposium: "Pathogen manipulation of plant defenses against natural enemies" (A. Wilczek, A. Bahrami, J. Russell, J. Dewdney, N. Pierce, F. Ausubel)
2004	IGERT Evolutionary Genomics Meeting: "Evidence for nutritional roles of secondary symbionts"
2003	University of Arizona, Center for Insect Science, Hexapodium: "How do the microbial guests of aphids earn their keep? Explaining the distributions of secondary symbionts within and across their host species"
2002	Society for the Study of Evolution Annual Meeting: "Barriers to horizontal transmission of insect-associated endosymbionts"
2002	Fourth International Symposium on Molecular Insect Science: "The distributions and transmission modes of aphid secondary endosymbionts"
2001	Entomological Society of America Annual Meeting: "The distribution and transmission modes of aphid secondary endosymbionts"