DISSERTATION RESEARCH: Islands on Islands on Islands: Bacterial Metacommunity Evolution in a Prairie Dog Landscape

University Of Colorado At Boulder, Boulder CO

Investigators

Abstract

Fleas can carry bacterial agents of disease from one animal to another, and from wild animals to humans. Whether a flea is capable of being a competent vector for pathogens depends on a number of different factors. An overlooked aspect of this process is the dynamics of bacterial communities that live within the gut of fleas. Fleas do not carry a single species of bacteria, but an entire community, and the composition and assembly of the bacterial community may influence whether fleas are capable vectors. This project seeks to assess the effects of space, time, and inter-specific interactions on bacterial community assembly within fleas that infect prairie dogs. Fleas were collected in 2004 and 2007 from animals living in discrete colonies. DNA was extracted from hundreds of fleas, and pyro-sequencing will be used to generate hundreds of thousands of bacterial DNA sequences from the flea DNA samples. These bacterial DNA sequences will be used to determine if bacterial communities are more similar within a certain prairie dog colony (space), within a certain year (time), and if interactions between bacterial lineages govern community assembly. In addition, phylogenetic techniques will be used to relate bacterial community assembly to flea and prairie dog population structure. This work will advance studies of the dynamics of bacterial communities within disease vectors, and will focus attention on a little studied but potentially important issue: namely, whether the composition of bacterial communities within vectors varies significantly and if such variation can explain variation in vector competency. Furthermore, this work will dove-tail with the increasing emphasis on describing and understanding the microbial ecosystem that is an individual.