Eight students have been selected to represent the University of Tennessee, Knoxville at the 2017 Posters at the Capitol event, March 1, 2017 in Nashville, TN.
Student: Rena Abdurehman
Faculty Mentor: Barry Bruce
Project Title: Quantitative and Qualitative Analysis of Protein Trafficking in Pea Protoplast Plastids
Abstract: Proper subcellular protein localization is integral to the function of all eukaryotic cells. Transient yellow fluorescent protein (YFP) expression provides a simple, visible, and quantitative assay for the monitoring of protein localization in living cells. Using YFP as a reporter, we will be transiently expressing a chimeric RuBisCO transit peptide utilizing Pisum sativum (pea) protoplasts. Protoplasts are often used in protein trafficking studies for their easy uptake of foreign genes due to their lack of the protective cell wall. Despite being the primary system for in vitro import studies, a reliable protocol does not exist for peas. Our research focuses on developing robust and rapid methodologies for isolating pea protoplasts from developing leaves. Our parameters include protoplast isolation, purity, and transfection methodologies. With a highly efficient transformation protocol, we will then isolate chloroplasts from the transfected protoplasts. Our research also focuses on the quantitative and qualitative analysis of subcellular protein localization using optical imaging, FACS, and immunoblotting analysis. We intend on providing a highly efficient method of analysis for transient gene expression in the most relevant and pertinent in vivo plant cell system, differentiated chloroplast. Our studies can be further applied to test the subcellular signaling pathways and localization of an array of different proteins utilizing the model plant species, Pisum sativum.
Student: Alana Cooper
Faculty Mentor: Jeff Larsen
Project Title: Dynamic Modeling of Human Emotions
Abstract: The aim of this research was to analyze emotional instability through different quantitative approaches. Participants from undergraduate introductory psychology classes recorded their own emotions while viewing video clips intended to elicit different emotions, while ten individual coders viewed recordings of the participants watching the video clips. A large database of emotional affect felt during the film clips was used in the three approaches. Primarily, data were visualized, leading to the conclusion that emotional stability did occur while the participants were watching the film. Markov chain models were created in order to model how an individual will move through affective space and to find the stability of positive, negative, neutral and ambivalent states. Another goal of the research was to find “home bases,” or steady affective resting places, for each of the participants. Different packages in MATLAB were used in order to find individual “home bases”. Another MATLAB package was used to find agreement between the coders who analyzed facial expressions of the participants. Overall, mathematical and computational methods confirm that emotional instability occurs most frequently when an individual has deviated from their home base, or their most stable state.
Student: Abby Durick
Faculty Mentor: Aleydis Van de Moortel
Project Title: Late Helladic Potmarks at Mitrou (ca. 1650-1100 BCE)
Abstract: This project examines Aegina’s role in regional maritime trade relations with the Bronze Age islet of Mitrou in East Lokris, Greece during the Late Helladic period (ca. 1650-1100BCE). Mitrou contains the fourth largest assemblage of potmarks with 48 mark types and 102 examples of known potsherds with marks. At Mitrou, 35 of 48 mark types only appear once. This may indicate a change in manufacturing groups or might imply a different meaning as the potmark is now located on a visible portion of the vessel unlike the potmarks placed on bases in earlier periods. This may be representative of different groups’ vessels when placed in a kiln used by multiple craftsmen at one time. This study on Aeginetan potmarks is significant to better understand the early economic and social relationship which facilitated a long-term trade relationship. On Mitrou, an elite was forming in the early phases of the Late Bronze Age, and three of the four LH I phase finds with Aeginetan potmarks appear in elite contexts on the islet. Potmark studies help inform about economic manufacture, post production, and trade between settlements, and likely have much more to offer and should be revisited once sites are excavated further.
Student: Clayton Nunn
Faculty Mentor: Dan Roberts
Project Title: Arabidopsis thaliana NIP2;1 is a Root Specific Lactic Acid Channel induced during Hypoxia Stress
Abstract: Arabidopsis thaliana NIP2;1 is a core hypoxia-induced gene that encodes a member of the nodulin26-like instrinic protein family of aquaglyceroporin channels. Unlike other family members, the AtNIP2;1 is a water impermeable channel that selectively transports protonated lactic acid, and is induced rapidly during anaerobic stress. Based on quantitative-PCR and promoter::GUS experiments, AtNIP2;1 is elevated acutely and rapidly under anaerobic conditions, increasing >1000-fold in roots within 2 hr post hypoxic treatment, and accumulating to particularly high levels within the cells within the stele of differentiated Arabidopsis roots. Under these conditions, translational fusions of NIP2;1 and flourecent protein reporters show high accumulation within phloem tissue with a significant number of cells showing polarized localization to the tips of phloem cells. Experiments with T-DNA insertional mutants of the AtNIP2;1 gene showed that the reduction of AtNIP2;1 expression correlates with several changes in the metabolic profiles of a number of metabolites. Under normoxic growth conditions, T-DNA insertional mutants grew normally, but show differential survival rate in response to anaerobic stress compared to wild type plants. The potential role of AtNIP2;1 as a lactic acid specific channel mediating the homeostasis of this fermentation end product will be discussed (supported in part by National Science Foundation Award MCB‐1121465).
Student: Sarah Ottinger
Faculty Mentors: Sindhu Jagadamma
Project Title: Effect of transgenic switchgrass cultivation on soil quality
Abstract: Though switchgrass is widely accepted as a bioenergy feedstock, there exists a major challenge in efficient conversion of switchgrass biomass to biofuel due to the high lignin content in its cell wall tissue. To solve this problem, transgenic switchgrass plants containing altered levels of lignin have been developed by genetic manipulation. However, lignin is an important component of soil organic matter(SOM). Residue of plants with altered cell walls might alter SOM and nutrient cycling and overall soil quality. We hypothesized that soils planted with transgenic switchgrass would affect SOM cycling differently than soils planted with non-transgenic switchgrass. We collected soil samples from two transgenic switchgrass plots at the East Tennessee AgResearch and Education Center in Knoxville; both plots included replicates of transgenic and non-transgenic switchgrass plants. Preliminary results indicate no difference in total SOM between transgenic and non-transgenic plots. Detailed examination is currently being undertaken on, potentially mineralizable carbon content, and microbially respired carbon to carbon dioxide. This research is expected to provide comprehensive understanding of the effect of genetically modified biofuel feedstock plants on soil processes leading to sustainability of production systems.
Student: Haley Porter
Faculty Mentor: Dallas Donohoe
Project Title: How Colonocyte Metabolism Shifts in Colorectal Cancer
Abstract: Dietary fiber has been proposed to protect against colorectal cancer. Butyrate, a fiber metabolite that is produced by bacteria in the colon is known to inhibit cell proliferation and promote cell differentiation, while also inducing apoptotic cell death in colorectal cancer cells at physiologically relevant concentrations. Unlike the majority of cells in the human body that prefer utilizing glucose, colonocytes use butyrate as the primary energy source. However, colorectal cancer cells shift away from utilizing butyrate towards glucose (the Warburg effect) leading to the accumulation of butyrate in the nucleus. Once in the nucleus, butyrate can act as an inhibitor of histone deacetylases to decrease proliferation and promote apoptosis. Here, we sought to determine how the oxidation of butyrate is impacted by knocking down pyruvate kinase M2 (PKM2), a key enzyme in glycolysis necessary for tumor growth, in colorectal cancer cells.
In this study, we used a lentivirus approach to knockdown PKM2 in HCT116 colorectal cancer cells. The efficiency of knockdown was confirmed by western blot. Butyrate oxidation was accessed using an XF24Analyzer, which measures oxygen consumption in real time. We found that when PKM2 is knocked down, cells exhibit an increase in butyrate oxidation. Additionally, PKM2 deficiency altered butyrate’s ability to slow cell proliferation. These data suggest the perturbation of pyruvate kinase isozyme M2 in colorectal cancer cells may shift metabolism towards butyrate oxidation and away from the Warburg Effect. This is clinically important to understand the potential of dietary fiber in cancer treatment and prevention.
Student: Adaya Troyer
Faculty Mentor: Tami Wyatt
Project Title: Preschool Children: What they know about asthma and how they learn
Abstract: Childhood asthma is a growing societal problem that causes suffering for children and families. Short of finding a cure, the best way to address this health concern is to give children with asthma the resources they need to control their condition. Unfortunately, research and resources for young children with asthma are lacking. The authors hypothesize using age-appropriate education via technology, which promotes self-regulation with psychosocial elements, could decrease exacerbations and establish healthy habits. This qualitative, descriptive study uses in-depth semi-structured interviews and direct participant observation to explore preliterate children’s (3-5 years) understanding of asthma causes, symptoms, and treatments and educational strategies for this age group. Preliterate children who meet at least 3 out of 4 of the National Asthma Education and Prevention Program (NAEPP) criteria are interviewed to determine cognitive development and understanding of asthma and are then allowed a free-play period to help determine the children’s preferences for entertainment and educational tools. A systematic evaluation of texts (e.g., field notes, transcripts) will provide qualitative data to categorize and identify themes. Additional analysis will determine what elements of the entertainment tools are most attractive to children in this age group by evaluating time spent with the toys and children’s physical and verbal responses during the play period. These data are the foundation to develop future educational materials that enhance cognitive understanding and health-related behavioral regulation in preliterate children diagnosed with asthma.
Student: Brandon Wilbanks
Faculty Mentor: Cong Trinh
Project Title: Engineering Bacteria to make Natural Scents from Chemical Wastes
Abstract: Aromatic aldehydes have a wide range of useful applications, from flavors and fragrances to pharmaceutical precursors and plastic additives. A large majority of these aldehydes are produced at low yield and over toxic catalysts. This gives rise to the need to produce these molecules in a renewable, environmentally friendly, and high-yield manner. Our project aims to meet these goals by developing a synthetic biology route to generate a library of aromatic aldehydes from their respective inexpensive toluene-based precursors that are an environmentally toxic waste in crude oil processing. We utilize the xyl ortho pathway of Pseudomonas putida, which is cloned into Escherichia coli as a host platform. This pathway converts toluene derivatives with a wide range of functional groups in the meta and para positions on the ring to their corresponding aromatic aldehydes, leaving the meta and para substituents unaltered and therefore allowing for development of a library of products.