Projects

Electron micrograph of vesicular stomatitis virus particles

Evolution of virus specialists and generalists

Arthropod-borne viruses (arboviruses) are able to infect arthropods (insects, ticks) as well as other host organisms. For this reason, arboviruses typically encounter alternating host environments in the wild, and have evolved to feature very broad host ranges. We use the RNA arbovirus vesicular stomatitis virus (VSV) as a model to examine the evolutionary and molecular genetics of host adaptation.

One study...

Colorized electron microscope image of herpesviruses (yellow and green spheres) coinfecting a single cell. During coinfection, sexual reproduction can produce viral progeny that contain a mixture of genes found in the coinfecting parents.

Evolution of Thermotolerance and Life-History Trade-Offs

We are using phage Φ6 as a model to study how segmented RNA viruses evolve increased stability (survival) under various environmental stressors (McBride et al. 2008, BMC Evol Biol 8:231). Challenges such as elevated heat, increased salinity and lowered acidity can cause virus particles to quickly degrade, and to lose their ability to...

Two bacterial cells caught in the act of plasmid-mediated conjugation. Many plasmids are able to transfer horizontally from an infected donor (top) to an uninfected recipient (bottom) via conjugation. Conjugation is initiated by contact between donor and recipient cells via a plasmid-encoded protein appendage called a sex pilus. Conjugation results in the one-way transfer of a copy of the plasmid genome from donor to recipient.

Evolution of horizontal transfer in E. coli plasmids

For many parasites, a fundamental conflict should exist between modes of horizontal (infectious) and vertical (intergenerational) transmission. Parasite activities that increase infectious transmission are presumed to generally reduce host fitness (growth rate). In turn, reduced host fitness impedes vertical transmission of the parasite and thereby causes a tradeoff between transmission routes...