The Ebbs Lab focuses primarily on the evolutionary relationships of helminth parasites (trematodes and cestodes) and their hosts (waterfowl and snails) and how host-specific traits (i.e. migration, distribution, habitat choice ect…) influence parasite evolution. We use a combination of ecological, traditional, and next-generation sequencing to assess phylogeographic and population genetic patterns among parasite lineages. For more information about specific projects and publications see below.
Invasion genetics of Physa acuta and implications for parasite transmission and distribution
Left: Austrobilharzia sp. collected in North Carolina Middle: Ph.D. co-adviser Dr. Sam Loker and E.T. Ebbs examining raccoons collected in Lousiana for Heterobilharzia Right: Dendritobilharzia pulverulaenta adult collected in New Mexico
Intra-specific variation and diversification of Schistosomatidae
Left: Red Shoveler (Anas platalea) pair in Argentina, Middle: Ph.D. adviser Dr. Sara Brant collecting hosts in Freestate South Africa, Right: E.T Ebbs and Dr. Sara Brant collecting specimens in Argentina
Schistosomes (Schistosomatidae) are parasites of birds and mammals of significant medical and veterinary importance. Across the family, there is substantial variation in host-use, distribution, morphology and intra-host habitat. this research aims to develop novel genetic markers to resolve evolutionary relationships among this enigmatic group of worms. We use a sequence capture approach to target ultraconserved elements via Illumina NGS for phylogenomic analysis.
Of particular interest is the schistosome gene Trichobilharzia, a speciose and globally successful group of duck parasites, a primary goal is to understand what factors have led to its success. To address these interests we have collected Trichobilharzia species from across the globe and use molecular genetic data (mtDNA, UCE loci) to estimate phylogeographic, demographic and population genetic patterns. These tools help us understand the evolutionary history and genetic makeup of these parasites species, allowing us to begin to tease apart factors that may have been important to Trichobilharzia diversification, as well as other parasite groups
Ebbs, E.T., Loker, E.S., Davis, N.E., Flores, V., Veleizan, A. and Brant, S.V., 2016. Schistosomes with wings: how host phylogeny and ecology shape the global distribution of Trichobilharzia querquedulae (Schistosomatidae).International journal for parasitology. DOI: 10.1016/j.ijpara.2016.04.009
Ebbs, E., Loker, E., Locke, S., Davis, N., Tkach, V., & Brant, S. (2021). Legacy parasite collections reveal species-specific population genetic patterns among three species of zoonotic schistosomes (Trematoda: Schistosomatidae). Authorea Preprints.
Ebbs, E.T., Loker, E.S., Bu, L., Locke, S.A., Tkach, V.V., Devkota, R., Flores, V.R., Pinto, H.A. and Brant, S.V., 2022. Phylogenomics and Diversification of the Schistosomatidae Based on Targeted Sequence Capture of Ultra-Conserved Elements. Pathogens, 11(7), p.769.
Community Genetics of Waterfowl Holobiome
The Ebbs lab was recently award a three-year NSF award to investigate the helminth and viral communities associated with North American waterfowl, specifically comparing 4 species of dabbling ducks and 4 species of diving ducks.
Aim 1: Are infracommunities conserved within and/or among host species?
Characterize helminth and viral communities within the targeted waterfowl species, to understand species richness and community structure.
Aim 2: Do host-traits predict population genetic parameters across symbiotic taxa?
Estimate population structure, effective population sizes and genetic diversity of core (>70%) symbiont taxa from each host species, to test the hypothesis that specific host- traits impact symbiont microevolutionary patterns related to increased transmission.
Left: Biomphlaria sp. shedding trematodes in Argentina Middle: Undergraduate researcher collecting Physa acuta in New Mexico Right: Lava Lake collection site in Montana.
Physa acuta is a globally invasive snail native to North America, and an important host to avian schistosomes and other digenetic trematodes. Using traditional genetic markers we have characterized phylogeographic and population genetic structure within the native range of P. acuta and reconstructed its invasion history.
In 2022 The Ebbs Lab was awarded the Robert O. Fehr Professorship to further our study of P. acuta population genetics within their native range. We are currently investigating ways to genotype distinct and sympatric haplogroups within North America using field and museum collections, to better understand why some P. actua haplogroups appear to be better invaders than others.
Ebbs, E.T., Loker, E.S. and Brant, S.V. 2018. Phylogeography and genetics of the globally invasive snail Physa acuta Draparnaud 1805, and its potential to serve as an intermediate host to larval digenetic trematodes. BMC Evolutionary Biology, 18:103, https://doi.org/10.1186/s12862-018-1208-z
E.T. Ebbs. 2018. Evolutionary ecology of host-parasite relationships: Role of host ecology, phylogeny, and demographics in shaping parasite evolution. Ph.D Dissertation, University of New Mexico. http://digitalrepository.unm.edu/biol_etds/263/
Ebbs, E.T., Loker, E.S. and Brant, S.V. First molecular genetic evidence for the invasion of Radix auricularia into North America. Manuscript in prep.
Loker ES, Dolginow SZ, Pape S, Topper CD, Alda P, Pointier JP, Ebbs ET, Sanchez MC, Verocai GG, DeJong RJ, Brant SV. An outbreak of canine schistosomiasis in Utah: Acquisition of a new snail host (Galba humilis) by Heterobilharzia americana, a pathogenic parasite on the move. One Health. 2021 Dec 1;13:100280.
Taylor ME, Auten CR, Foster T, Ebbs E, Hofkin BV. Canine ocular onchocerciasis in New Mexico: Risk factors for disease. Veterinary Ophthalmology. 2021 May;24(3):288-94.