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Paragordius obamai
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Research -> Current Research


University of New Mexico:

Ben's research integrates the disciplines of parasitology, immunology, ecology, evolution, and genetics to study the underlying causes and principles of host-parasite specificity.  Host-parasite specificity, or Who is infected with whom and why?, is one of the unifying principle concepts in parasitology.  Host specificity, in a broad sense, defines the parasite’s niche; each parasite species inhabits a specific and unique variety of host species.  However, the ultimate and proximate determinants leading to the success or failure of host-parasite combinations are not well understood.  Ben's overall research goals are to comprehend the processes that shape host specificity, and to study factors influencing host-parasite interactions. 

In order to understand mechanisms leading to host specificity we must first have a solid understanding of the filters responsible for mediating host-parasite interactions.  These filters include factors such as ecosystem structure, genetics, immunology, and behavior.  By fully understanding the filters involved, it will be possible to put together the ‘recipe’ needed by successful host-parasite combinations and identify ‘ingredients’ that are lacking from unsuccessful combinations.

Work at UNM focuses on exploring these filters and understanding how they influence compatibility.  Study of these filters has led Ben's research to be expansive and interdisciplinary involving fieldwork, taxonomy, phylogenetics, laboratory experimental infections, molecular genetics, and genomics.  For his work, he is focusing on hairworms as a model system,  which has allowed him to the unraveling of their life cycle, transmission dynamics, ecology, and evolution.

Ben has recently started studying the interaction of the immune system of parasites and their hosts.  He is interested in 2 questions: First, can parasites evolve to use their immune system to protect hosts?  When parasites destroy the host’s immune system, can the parasite amend the host’s defenses?  Second, can parasites evolve to use the host immune system to protect themselves?  Many parasites live in hosts with well working immune systems and feed by cuticle absorption, allowing them to avoid pathogen encounters.  In these cases, can the parasite evolve to simplify its immune system and rely on the absorption of host defense molecules to amend their own defenses?  Gaining a better understanding of how these immune systems interact will elucidate whether matching of such systems plays a part in host-parasite specificity.  Because of the multidisciplinary nature of ecological/evolutionary parasitology, this type of work attracts students with a variety of backgrounds and skills, and undergraduate and gradu ate student research can be incorporated into all aspects of my work.  Depending on the student’s interests and time constraints, they can be involved in fieldwork, lab work, necropsies, host and parasite identifications, animal husbandry, taxonomy, systematics, genomics, and immune assays.

Oklahoma State University:

Matt's research interests are in the area of parasite ecology, evolution of parasite life cycles, and parasite taxonomy. He utilizes parasites of amphibians and aquatic invertebrates in order to investigate parasite ecology and evolution because lower vertebrates and invertebrates have invaded a multitude of micro-habitats and exhibit a striking diversity of life histories, reproductive strategies, body sizes, foraging modes, and trophic relations. They serve as both intermediate and definitive hosts and their parasite fauna is diverse.

Therefore, these hosts provide a good model to Matt for studying biotic and abiotic ecological factors that determine parasite species’ distribution, abundance, and movements through ecosystems. This system enables Matt's laboratory to investigate questions of how host and parasite life histories co-evolve, and affect parasite community structure, parasite biogeography, and distribution in time and space.

University of Hamburg:

The main focus of the research of Andreas is the morphology, taxonomy and phylogeny of horsehair worms. Apart from this he is very interested in the life cycle.

Andreas uses different microscopical techniques to receive information on the external and internal anatomy of nematomorphs. Scanning Electron Microscopy (SEM) is an ideal tool to reliably document fine structures of the cuticle, which is a prerequisite for exact determination. Transmission Electron Microscopy (TEM) of thin slices allows detailed information of the internal anatomy. Information from serial sections allows the reconstructions of organs. Confocal Laser Scanning Microscopy is used to document the architecture of structures previously labelled specifically by fluorescent markers. Currently the musculature and the nervous system of larvae and adults are investigated.

The establishment of high magnifying techniques such as SEM have made the recognition of fine cuticular structures more reliably than it was possible before. However, many species have to be reinvestigated, because their documentation is not sufficient enough. New species are constantly discovered, but also “old” species and even genera are recognized to be synonymous to already described ones. One aim of Andreas is, in collaboration with various colleagues, to provide reviews and keys for all nematomorph genera. In most cases, such reviews do not exist and the vast primary literature has to be considered if one wants to determine a specimen.

The recognition of species is made difficult by the fact that some characters such as body size, colour, but probably also some cuticular characters vary from specimen to specimen within one species. In such cases, molecular markers can help to distinguish specimens of almost similar looking species from differently looking specimens of one species. Such work is currently being done for a population of Central German horsehair worms which might represent two species.

To learn more about any of these labs or the reserachers, please click HERE and follow the appropriate links.



Copyright 2014 Ben Hanelt, Matt Bolek, and Andreas Schmidt-Rhaesa
Updated: July 2015