Invertebrate Evolution and Symbioses
Our team investigates evolutionary, genetic, and symbiosis questions in a variety of invertebrate animal systems that include nematodes, gastropods, and annelids. We examine natural variation in host-symbiont interactions, and evolutionary & population-genetic processes at local and global scales. A variety of laboratory and analytical strategies are deployed in this research that includes PCR, Sanger & Illumina DNA sequencing, laboratory infectivity trials and mesocosms, and light & confocal microscopy. This research relies on collaborations with academic, government, and industry partners. Current projects are funded by the USDA, Oregon Seed Council, and BASF.
Nematode-Gastropod and Nematode-Annelid Interactions
We investigate the dynamics of interactions between terrestrial gastropods (slugs & snails) and nematodes that parasitize them. This research is done in collaboration with Rory Mc Donnell and his research team at OSU, and Lien Luong and her research team at the University of Alberta. We examine the evolution and host specificity of Phasmarhabditis spp. nematodes, which parasitize grey field slugs (Deroceras reticulatum) and other pest slugs that are invasive in North America and other parts of the world. These nematodes are commercialized biocontrol products in the European Union, Canada, and Kenya, but are not currently on United States markets. However, our team has found them in California, Oregon, and Washington. We are currently trying to better understand the global distribution patterns of Phasmarhabditis spp. nematodes, and their potential impacts on non-target gastropod species endemic to the Pacific Northwest of North America.
Nematode-Plant Interactions
Our research includes the investigation of diverse plant-parasitic nematode species (e.g., Globodera spp. Pratylenchus spp., Radopholus spp., Xiphinema spp.) and their bacterial endosymbionts in collaboration with Inga Zasada's lab at USDA-ARS in Corvallis, and others. We applied genome skimming strategies to discover new endosymbiont lineages (Wolbachia spp., Cardinium spp.) in plant-infecting nematodes, and are interested patterns of coevolution between the nematodes and their bacterial symbionts.
Banana Slug Genetics
We recently launched research on the genetic diversity of Pacific Banana Slugs, Ariolimax columbianus, in Corvallis and other parts of the Pacific Northwest. We are interested in how urbanization and other factors shape the diversity and distribution of this species and other gastropod lineages endemic to the Pacific Northwest.
Recent Publications
Student Theses
Brune, Max. 2022. An analysis of the population genetic structure of Ariolimax columbianus around Corvallis, Oregon. University Honors College Undergraduate Thesis.
Wasala, Sulochana. 2020. Evolutionary Dynamics of Genomes and Endosymbionts in Plant-Parasitic Nematodes. Integrative Biology PhD Dissertation.
Ha, Anh. 2019. Orbiting the Genus of False Units: Dynamics of Phage Genomes and Nematode Microbiomes Associated with Pseudomonas spp. Integrative Biology PhD Dissertation.
Research Articles
RJ Mc Donnell, A Colton, DK Howe, DR Denver. 2022. Susceptibility of Testacella haliotidea (Testacellidae: Mollusca) to a U.S. strain of Phasmarhabditis hermaphrodita (Rhabditidae: Nematoda). Biocontrol Science and Technology 32: 262-266.
DK Howe, AD Ha, A Colton, IT De Ley, RG Rae, J Ross, M Wilson, J Nermut, Z Zhao, RJ Mc Donnell, DR Denver. 2020. Phylogenetic evidence for the invasion of a commercialized European Phasmarhabditis hermaphrodita lineage into North America and New Zealand. PLoS One 15: 8.
SK Wasala, AMV Brown, J Kang, DK Howe, A Peetz, IA Zasada, DR Denver. 2019. Variable Abundance and Distribution of Wolbachia and Cardinium Endosymbionts in Plant-Parasitic Nematode Field Populations. Frontiers in Microbiology 10: 964.
Nematode-Gastropod and Nematode-Annelid Interactions
We investigate the dynamics of interactions between terrestrial gastropods (slugs & snails) and nematodes that parasitize them. This research is done in collaboration with Rory Mc Donnell and his research team at OSU, and Lien Luong and her research team at the University of Alberta. We examine the evolution and host specificity of Phasmarhabditis spp. nematodes, which parasitize grey field slugs (Deroceras reticulatum) and other pest slugs that are invasive in North America and other parts of the world. These nematodes are commercialized biocontrol products in the European Union, Canada, and Kenya, but are not currently on United States markets. However, our team has found them in California, Oregon, and Washington. We are currently trying to better understand the global distribution patterns of Phasmarhabditis spp. nematodes, and their potential impacts on non-target gastropod species endemic to the Pacific Northwest of North America.
Nematode-Plant Interactions
Our research includes the investigation of diverse plant-parasitic nematode species (e.g., Globodera spp. Pratylenchus spp., Radopholus spp., Xiphinema spp.) and their bacterial endosymbionts in collaboration with Inga Zasada's lab at USDA-ARS in Corvallis, and others. We applied genome skimming strategies to discover new endosymbiont lineages (Wolbachia spp., Cardinium spp.) in plant-infecting nematodes, and are interested patterns of coevolution between the nematodes and their bacterial symbionts.
Banana Slug Genetics
We recently launched research on the genetic diversity of Pacific Banana Slugs, Ariolimax columbianus, in Corvallis and other parts of the Pacific Northwest. We are interested in how urbanization and other factors shape the diversity and distribution of this species and other gastropod lineages endemic to the Pacific Northwest.
Recent Publications
Student Theses
Brune, Max. 2022. An analysis of the population genetic structure of Ariolimax columbianus around Corvallis, Oregon. University Honors College Undergraduate Thesis.
Wasala, Sulochana. 2020. Evolutionary Dynamics of Genomes and Endosymbionts in Plant-Parasitic Nematodes. Integrative Biology PhD Dissertation.
Ha, Anh. 2019. Orbiting the Genus of False Units: Dynamics of Phage Genomes and Nematode Microbiomes Associated with Pseudomonas spp. Integrative Biology PhD Dissertation.
Research Articles
RJ Mc Donnell, A Colton, DK Howe, DR Denver. 2022. Susceptibility of Testacella haliotidea (Testacellidae: Mollusca) to a U.S. strain of Phasmarhabditis hermaphrodita (Rhabditidae: Nematoda). Biocontrol Science and Technology 32: 262-266.
DK Howe, AD Ha, A Colton, IT De Ley, RG Rae, J Ross, M Wilson, J Nermut, Z Zhao, RJ Mc Donnell, DR Denver. 2020. Phylogenetic evidence for the invasion of a commercialized European Phasmarhabditis hermaphrodita lineage into North America and New Zealand. PLoS One 15: 8.
SK Wasala, AMV Brown, J Kang, DK Howe, A Peetz, IA Zasada, DR Denver. 2019. Variable Abundance and Distribution of Wolbachia and Cardinium Endosymbionts in Plant-Parasitic Nematode Field Populations. Frontiers in Microbiology 10: 964.
