Overview

The main focus of the laboratory is to use a molecular ecology approach to elucidate the biodiversity, ecology, and evolution of parasites. Because parasites are small and inhabit inconspicuous places (e.g., the gut of a vertebrate), it is difficult and sometimes impossible to directly observe the population dynamics of parasites. However, the use of genetic markers and population genetics theory allows the indirect inference of many population demographic processes such as dispersal, mating dynamics, and transmission patterns. Ongoing research efforts address both basic and applied questions spanning the intersections of genetics, evolution, and ecology. We largely focus on macroparasites (e.g., nematodes, flatworms), but are open to other parasitic systems.

If you are a prospective student interested in working in the lab, or have questions about our research, feel free to contact us.

Ongoing projects include:

1. The biodiversity, ecology, and evolution of the genus Alloglossidium
2. Parasite mating system and transmission dynamics, and host immune evolution in a gecko-tapeworm system, and
3. Schistosome linkage mapping.

Many digeneans have a 3-host life cycle (e.g., snail first-intermediate host, invertebrate second-intermediate host, and vertebrate definitive host). The definitive host is where the flukes will sexually mature and reproduce, while parasite larval stages are in the intermediate hosts. The genus Alloglossidium is unique in that 12 of the 14 known species can precociously produce offspring within what is typically regarded as the second-intermediate host. As there is variation in life cycle patterns (2- or 3-host) and definitive host species use (catfishes, crustaceans, and leeches) within the genus, this system can serve as a model for understanding the evolutionary origins and impacts of life cycle complexity. We have several goals in this project including elucidating the biodiversity, phylogenetic hypothesis testing, and comparative population genetics. We have already collected many of the species in the genus and obtained DNA sequence data from both nuclear and mitochondrial genes. Thus, keep an eye out on our “News” link for publications on this project in the near future!

Our survey work will be conducted through 2/3 of the continental United States and will exemplify the untapped biodiversity in our own "backyard". With an aim to highlight the "backyard biologist" mindset and inspire others to look beyond the obvious organisms when spending time in the great outdoors we have created an online resource, the Trematode Field Guide which includes interactive distribution maps, species descriptions and pictures, and educational tools.

Collaborators:
Bill Font (Southeastern Louisiana University)

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We know very little about the mating system dynamics of parasitic helminthes. Mating dyanimcs are important In particular, our knowledge of hermaphroditic mating behaviors (e.g., self-mating vs. outcross-mating) in nature is virtually non-existant. We are using the Medeterranean gecko (Hemidactylus turcicus) and its tapeworm (Oochoristica javaensis) as a model system. Our goals are to determine selfing rates in the parasite and elucidate parasite transmission dynamics over time and several spatial scales. In addition, we have plans to host immune genes to determine if there are associations to parasite infections status. To date, we have characterized microsatellite and mitochondrial markers for the both the parasite and its host. So again, keep your eye on our “News” link for results stemming from this project.

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In 2009 we published the first genetic based linkage map of the human pathogen Schistosoma mansoni. Currently, in collaboration with Tim Anderson and Phil LoVerde, we are mapping drug resistance genes. Significant progress has been made on this front and Tim will be presenting data at upcoming meetings.

Collaborators:
Tim Anderson (Southwestern Foundation for Biomedical Research)
Philip LoVerde (UT Health Science Center)

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