Poster 72 – Undergraduate Research Symposium Abstracts

Effect of Pyomelanin Production on Oxidative Stress in an Aeromonas Zebrafish Gut Isolate

Presenter: Helena Klein

Faculty Mentor: Karen Guillemin, Cathy Robinson

Presentation Type: Poster 72

Primary Research Area: Science

Major: Biology

Bacteria have rapid growth rates, which allow us to study their adaptive evolution in the lab to selected environments. By studying the genetic changes that occur during the evolutionary process, we can learn about selective pressures experienced by bacteria when evolved in selected conditions. Through passaging of a strain of a natural zebrafish gut isolate, Aeromonas ZOR0001, we isolated one strain that has increased pigmentation compared to the wildtype. This pigmentation is a result of accumulation of pyomelanin in the extracellular environment. We confirmed through genetic sequencing a mutation in the isolate’s metabolic pathway known to be involved in pyomelanin production. Pyomelanin production has been shown in other organisms to be linked to increased resilience to oxidative stress. Therefore, we hypothesized this mutation confers a fitness advantage to this evolved isolate compared to the ancestral strain. Therefore we generated a genetic knockout of the mutated gene in the ancestral strain and used hydrogen peroxide to simulate oxidative stress in vitro. We found that the knockout strain did better than the wild type strain. This demonstrates that pyomelanin production confers resistance to oxidative stress in Aeromonas ZOR0001 which suggests an adaptive advantage for in vivo growth. Knowledge of genes that increase fitness in bacterial strains in the gut can ultimately allow for better probiotics to be developed with wide repercussions for human health.

Out of the Ashes: Examining Forest Biodiversity Conservation Efforts in Post-Conflict Vietnam and Sierra Leone

Presenter(s): Caitlin Scarpelli − General Science

Faculty Mentor(s): Philip Romero, Craig Kauffman

Poster 72

Research Area: Natural and Social Science

When the word paradise comes to mind, words like prosperity, nature, and peace do as well. There is one phrase that most likely does not: armed conflict. However, over the past 70 years, armed conflict has significantly overlapped with biodiversity hotspots, areas with both high species variety and high degradation. When armed conflict causes land-use changes, resource exploitation and pollution, direct damages to ecosystem health, ecosystem services and human health occur. Conservation seeks to protect natural ecosystems, but can also protect the people who are often ravaged by conflict. This thesis examines how countries in biodiversity hotspots implemented strategies for forest biodiversity conservation in post-war periods and proposes a conservation strategy which any country could theoretically implement after armed conflict. I utilized the Most Different Systems Design, which seeks to identify similar factors between two extremely different case studies, to compare conservation efforts by the Vietnamese and Sierra Leonean governments. My time frame was 16 years after their respective conflicts ended: between 1975 and 1991 after the Vietnam War, and between 2002 and 2018 after the Sierra Leone Civil War. Both countries sought to increase their conservation capacity post-conflict, whether through increasing governmental funding, passing conservation policies, or creating protected areas. While conservation can occur through various methods, establishment of protected areas was essential for successful forest conservation. However, forest conservation was unsuccessful when local people were not consulted. Therefore, an emphasis on communication, coordination, and collaboration between departments and local people is vital for successful forest conservation.

A Lithostratigraphic Analysis of the Crooked River Mascall Formation

Presenter(s): Alexandra Thompson

Faculty Mentor(s): Samantha Hopkins

Poster 72

Session: Sciences

This project presents a comprehensive lithological and biostratigraphic record of the Miocene Mascall Formation deposits of the Crooked River Basin in Central Oregon. The Columbia River Basalt Group (CRBG) covered the Crooked River Basin and much of the Pacific Northwest in the middle Miocene, altering the landscape and ecosystem. As a result of this event, an analysis of the depositional history of this region is worthwhile because it explores the impact of large scale basalt flows on subsequent basin evolution. University of Oregon geology students have measured stratigraphic sections in four different locations across the Crooked River basin in order to quantify the differences in depositional history across the basin. The sites are stratigraphically situated between the lower boundary CRBG and upper capping Rattlesnake Ash Flow Tuff (RAFT). For each region, we have created a representative stratigraphic column, and correlated rock units between the regions. The Mascall Formation in the Crooked River Basin is consistent with published descriptions of the Lower Mascall Formation: mostly fine siltstone and sandstone with diatomite, ash, and chert deposits and some tuff strata (Bestland, 1998). Each of the four sites share characteristics of the Lower Mascall which suggests similar depositional environments across the sites; however, the sections vary in the thickness and representation of individual identifiable strata, suggesting variation in where deposition was greatest through the half-million years of the section. This is the first comprehensive assessment of the stratigraphy of the Crooked River Basin, which has significant implications for understanding landscape reorganization following volcanism.

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