Environmental Variability and Evolution of Virus Specialists and Generalists

Yale University, New Haven CT

Investigators

Abstract

Whereas some viruses can easily shift to infect new host populations, other viruses remain confined to their original host. This research examines the environmental factors which cause viruses to be specialists that infect few hosts or generalists that attack a variety of hosts. This goal is accomplished using experimental evolution of Vesicular Stomatitis Virus in laboratory culture. The first major objective is to see if different patterns of host availability affect whether specialist or generalist viruses will evolve, and can be used to predict which viruses are more likely to shift to new hosts in the future. Second is to identify the changes to the virus genome that are associated with evolved host shifts. Third is to determine whether populations of specialist and generalist viruses differ in the rate at which they evolve. Methods include techniques from a variety of disciplines, including molecular biology, population genetics, genomics and evolutionary theory. The project results can be applied to several systems because viruses are important disease agents in wild and domesticated populations of animals and plants. The project virus resembles many vector-borne human viruses (such as West Nile Fever Virus); thus, the project should help elucidate environmental factors promoting viral host shifts into human populations.