Biology and Psychology Summer 2015 Research Projects

Students - Anna Claire Atkins and Charlotte Marchioni
Faculty Mentor - Dr. Maureen McClung
Project Title - A Fracking Racket: Do Birds Change the Way They Sing When Experiencing Chronic Noise from Natural Gas Extraction?
Natural gas extraction via hydraulic fracturing has experienced a recent boom in the United States. This practice generates chronic noise that could interfere with the ability of birds to communicate acoustically. Previous research has shown birds in areas with anthropogenic noise to avoid masking effects by singing at higher frequencies and narrower bandwidths, and changing timing elements of their songs. In this project, we are studying the effects of noise on the structure of vocalizations of forest breeding birds in the Fayetteville shale, an area of intensive gas development in central Arkansas.
In the summer of 2015, we traveled to ten noisy sites near compressor stations and ten quiet sites near well pads and recorded the songs of singing males for common species such as the Northern Cardinal, Tufted Titmouse, Carolina Wren, Indigo Bunting, Black-and-white Warbler, Blue-grey Gnatcatcher, and the Red-eyed Vireo. Currently we are in the process of extracting frequency and timing data from spectrograms of these songs using a sound visualization and analysis software called Raven Pro. This fall, we will analyze the data to detect differences, if any, between the songs of birds in noisy areas and those breeding in areas unaffected by noise. Given that frequency and timing components are important in attracting mates, changes in songs could influence breeding success and population sizes of birds in this area of Arkansas that historically has been an important breeding ground for many species of resident and migratory birds.

Student - Blake Cooper
Faculty Mentors - Dr. Mark Sutherland and Dr. Rick Murray
Project Title - Investigating Biodiversity in a Restored Urban Watershed through New Curriculum
I worked with Dr. Sutherland and Dr. Murray to complete a new curriculum for the Cell Biology lab course, taken by almost half of incoming students. The curriculum will revolve around the Hendrix Creek Preserve, a drainage ditch recently converted into wetlands in order to improve flood control and water quality. The project aims to monitor the water quality and expanding biodiversity of aquatic microorganisms in the Hendrix Creek Preserve and also expose students to fieldwork and various scientific practices at the beginning of their undergraduate careers. I helped to develop a comprehensive lab manual, a faculty lab manual, a student procedures manual, instructions for how to keep a lab notebook, a photographic key of microorganisms, powerpoint presentations for pre-lab, and pre-lab quizzes. The students will use pond water collection, various microbiology and genetics techniques, and biochemical assays to monitor bacterial species (such as E. coli), microorganisms, and the quality of the water. I helped with the testing of many of the experiments this summer to ensure their success. This new curriculum will collect data for ongoing Creek Preserve research, as well as increase students' understanding and enjoyment of science.

Student - Alex Crocker
Faculty Mentor - Dr. George Harper
Project Title - Terroir in Arkansas: Exploring Natural Fermentation in the Natural State
This Summer, I am conducting research on the yeasts associated with Arkansas wine grapes. Grape berries, already rich with native yeasts, are crushed to produce a sugary must (right-hand photo). Although the "wine yeast" Saccharomyces cerevisiae is added to the must, other yeasts may proliferate throughout fermentation, contributing compounds which affect the body, flavor, and acidity of the wine. These yeasts have been shown to vary by region and by grape cultivar, potentially contributing to the regional and varietal character of wines.
Nearly all previous research has focused on cultivars of the European grape, Vitis vinifera, but the Muscadine, V. rotundifolia, and a hybrid cultivar called Cynthiana (Arkansas's state grape) (left-hand photo) are better adapted to the Arkansas climate, and are more often used in Arkansan winemaking. I have visited multiple wineries, where their benevolent winemakers have allowed me to sample all three of the grape varieties mentioned, as well as the musts produced from those grapes. Using culture independent DNA profiling I plan to assess differences in yeast populations between grape species within the same region, and to generate the first thorough account of the indigenous wine yeasts of Arkansas.
This is a project that I am truly excited about, and which I did not expect the opportunity to carry out as an undergraduate. Dr. George Harper, understanding that I have a special interested in alcoholic fermentation and yeasts, encouraged me to develop an original research project, and employed me in his laboratory to carry it out. I wrote the proposal for this project and received the funding necessary from Hendrix's Odyssey Program. The project has evolved with my understanding of the subject matter, and I look forward to seeing its results.

Students - Lauren Dickinson (top photo) and Jeanita McReynolds (bottom photo)
Faculty Mentor - Dr. Andrew Schurko
Project Title - Determining the Role of Meiotic Genes During Bdelloid DNA Repair
Bdelloid rotifers are unlike any other animal in that they are a class of entirely-female microinvertebrates with an unparalleled DNA repair ability. Although they have survived for over 40 million years without males or meiosis, bdelloids still possess four genes (SPO11, HOP1, MSH4, and MSH5) known to be specific to meiosis in other animals. Consequently, the focus of our project was to investigate the function of meiosis genes in an animal that lacks meiosis. Interestingly, bdelloids frequently desiccate and rehydrate, which causes a high concentration of DNA double-strand breaks that are repaired quickly and efficiently. Therefore, we wanted to determine if these meiotic genes have survived evolutionary degradation because of a functional relevance in the DNA repair system of bdelloids. First, to determine if the genes were protein-producing, we produced antibodies that identify HOP1 and SPO11 proteins. These antibodies were then used in western blot assays to verify that the bdelloid Adineta vaga is indeed producing these proteins. Later, we will subject the bdelloids to ionizing radiation (which mimics the effects of desiccation) to determine if the meiotic protein abundance is higher during DNA repair. Second, we generated meiotic proteins and DNA repair proteins that are tagged with a histidine chain. We will use these recombinant proteins in future assays to identify the binding partners of these proteins, which will give us insight as to the function of the meiotic proteins in bdelloid rotifers.


Students - David Dobry, Michelle Huynh, Alex McIntyre, and Tyler Ratliff
Faculty Mentor - Dr. Sara Taylor
Project Title - Toward a Novel Treatment to Prevent Stress-Induced Anxiety and Depression
Exposure to life stressors can increase a person's risk for the development of psychiatric disorders, such as anxiety and depression. Research suggests that this relationship may be mediated by the kappa opioid receptor (KOR) system. Our research goal was to determine whether blocking the KOR system with a KOR antagonist prior to three weeks of chronic stress could prevent the effects of chronic stress on anxiety- and depression-like behaviors and altered stress hormone levels in adult male rats.
Stressed rats gained less weight than control rats and exhibited enlarged adrenal glands, confirming that our stress paradigm was effective. We also found that pretreatment with the KOR antagonist prevented stress-induced anxiety-like behavior on the elevated plus maze, while neither stress nor the drug had an effect on depression-like behavior. Our findings suggest a specific role of KOR antagonism as a possible treatment for the anxiety that occurs due to chronic stress. Analysis of the interaction between KOR antagonism and chronic stress on inflammatory cytokines in the brain and plasma corticosterone (stress hormone) is ongoing.

Student - Sarah Eddington
Faculty Mentor - Dr. Mario Muscedere
Project Title - Effects of Body Size and Brain Neuromodulators on Olfactory Learning in Carpenter Ants (Camponotus americanus)
This summer I did research in Dr. Muscedere’s lab, where we study social complexity and division of labor in ants. I worked on a project designed to determine how body size variation and differences in brain neuromodulator levels affect learning ability in workers of the carpenter ant Camponotus americanus, possibly contributing to division of labor. Insects have long been used to study learning because their nervous systems are relatively simple yet they learn via many of the same conserved mechanisms as vertebrates. One example of this similarity is the biogenic amine neuromodulators (including dopamine, serotonin, and octopamine), which have important behavioral effects in vertebrates and invertebrates and are implicated in learning across taxa. We predicted that workers that were more likely to work outside the nest and thus encounter environmental odors associated with food would exhibit faster learning and more durable memory retention, and that this would be associated with higher brain biogenic amine levels. I performed behavioral observations to assess worker foraging behavior, experimentally measured learning ability in workers of different sizes, and used HPLC to determine neuromodulator levels in the brains of these workers. To assess learning, I used a classical conditioning assay in which a sucrose reward that would naturally elicit extension of the inner mouthparts was paired with an olfactory stimulus, and learning was assessed by the ability of the odor to later elicit extension in the absence of sucrose.
We hypothesized that larger ants would have better learning abilities because they are found outside the nest more often and were thought to do most of the foraging. However, while we did find that large workers were over-represented outside the nest, they were found much closer to the nest entrance on average, and we now believe that they perform mostly nest defense tasks, with smaller workers being more active foragers. In fact, smaller workers had better learning abilities and, after correcting for brain size differences, significantly higher levels of DA, OA, and 5HT in their brains than larger workers. I plan on continuing my work throughout the school year. Our upcoming research plans include (1) behavioral assays to directly test the foraging ability and motivation of workers of different sizes, and (2) experimental manipulations of brain neuromodulator levels to directly test whether higher aminergic activity improves learning performance.

Student - Kate Emery
Faculty Mentor - Dr. Jenn Dearolf
Project Title - Effects of Perinatal Exercise on the Enzymatic Properties of Neonatal Mouse (Mus musculus) Diaphragms
This summer has been my second summer to work in the Dearolf lab. In 2014, I completed a research project focusing on prenatal steroids and their effects on the development of breathing muscles in guinea pigs (Cavia porcellus). I then presented my findings at the annual Society for Integrative and Comparative Biology (SICB) meeting in January 2015 with a poster entitled "Morphology of a neonatal guinea pig (Cavia porcellus) accessory ventilatory muscle."
This summer, I took on a new project that employed many of the skills I learned during my previous work in the lab. I studied the effects of perinatal exercise on citrate synthase activity in the diaphragms of two-day-old mouse (Mus musculus) pups from exercised and non-exercised dams. First, I found an optimum dilution factor for analyzing citrate synthase activity in this muscle by graphing vmax (highest rate of conversation of substrate to product) vs. a range of dilution factors (1:20 - 1:170) and selecting a dilution factor from the linear portion of the curve. Then, I measured the citrate synthase activity in the two-day-old mouse pup diaphragm samples with a microplate reader using the optimum dilution factor. I am currently analyzing my data and will present my findings at the 2016 SICB meeting in Portland, Oregon. I also had time to contribute to Dr. Dearolf's existing data sets by helping to fill in missing information for the prenatal steroid studies.

Student - Laura Hildebrand
Faculty Mentor - Dr. Lindsay Kennedy
Project Title - The Reduction of Stress and Related Health Behaviors Through the Automaticity of Priming
This summer, I conducted an independent research project on the relationships between priming, stress, and certain health-related behaviors. Priming is the activation of certain associations within the brain. Once activated, the association then unconsciously affects your subsequent feelings, thoughts, and behaviors. Because priming, unlike many other health interventions, does not require self-control, I examined how the automaticity of priming might reduce stress-related health behaviors. Although this research as a whole is still ongoing, this summer's study yielded promising results, which I plan to explore during the school year.

Student - Eric Huynh
Faculty Mentor - Dr. Ann Willyard
Project Title - Integrative Data Techniques for Species Delimitation in Ponderosa Pine
My summer research was a bioinformatics project that worked on integrating data from different sources. I tested if adding more data would increase the percentage of assignment to our pre-defined groups. This means I took chloroplast, mitochondrial, ecological, and morphological data on the same populations of ponderosa pine trees and combined them together using Non-Metric Multidimensional Scaling (NMDS). I learned to create and manipulate distance matrices and to run scripts in the powerful R platform. I found that our hypothesis - the more types of data we add the more would be assigned - was supported. I presented my research in a poster at an international conference in Edmonton, Alberta, Canada in August.

Students - Alexander C. Jones and Miracline Ebijoyeldhas
Faculty Mentor - Dr. Andrew Schurko
Project Title - Examining the Role of Histone H2A Variants in Bdelloid Rotifer DNA Repair
This summer we worked with microscopic, aquatic animals called bdelloid rotifers. These animals are found in freshwater ecosystems worldwide. Intriguingly, bdelloids have a highly efficient DNA repair system that allows them to repair damage induced by desiccation and high doses of ionizing radiation. In all animals, DNA is packaged into compact chromosomes with the assistance of histone proteins. Histones act as spools around which DNA is wrapped. Due to their important role in chromatin structure, histone sequences are highly conserved. However, in bdelloid rotifers, certain histone proteins are unique among animals in that they have very long tails that extend from the protein. These tails may be targets for modifications that induce cellular processes such as DNA repair. The objective of our project was to study the role of these bdelloid histone proteins in their DNA repair. First, we exposed bdelloids to ionizing radiation and then extracted their histones. We used high-resolution mass spectrometry at UAMS to identify the histone variants that are present and the modifications that may be specific during DNA repair. Second, we used a variety of molecular biology techniques to engineer strains of E. coli that produce bdelloid histone proteins. We have purified these proteins from E. coli and we will use these in future studies to identify other proteins that bind to histones in bdelloids. Our findings will address the role histones in the specialized DNA repair system of bdelloids, which could have biomedical implications as well.

Student - Hassan Karemera
Faculty Mentor - Dr. Ann Willyard
Project Title - Mitochondrial lineages of Pinus ponderosa s.l. in the USA and related species in Mexico and Central America
My research was in collaboration with Dr. David Gernandt, herbarium curator at Universidad Nacional Autonoma de Mexico (Mexico City, Mexico). I traveled across the western U.S. to collect plant samples, and also analyzed samples from Mexican species that Dr. Gernandt provided. I learned to analyze chloroplast fragments and how to perform nucleotide sequencing and alignment for a very complicated repeat region of the mitochondrial genome.
My results show that some populations of what taxonomists call Pinus ponderosa are actually more closely related to Mexican species than to each other. I presented a poster at a conference in Edmonton, Alberta, Canada, where I had the chance to meet Dr. Gernandt. We laid out a plan to finish sampling so that we can publish these findings. My grant proposal to the Arkansas Academy of Science was funded, and I will have the opportunity to give an oral presentation at this important regional conference next spring. Along the way on our fieldwork, I also encountered a rattlesnake and swam in the Pacific Ocean!

Student - Julia Lefler
Faculty Mentor - Dr. Ann Willyard
Project Title - Phylogeography of Jeffrey Pine in the Klamath Mountains
My research began with writing two grant proposals. I was not awarded an ADHE SURF, but I did receive a research grant from the Arkansas Academy of Science. Our fieldwork involved traveling over 5000 miles and collecting at 16 sites in Wyoming, Idaho, Oregon, and California. After lab work and data analysis, I was able to support my hypothesis that the Jeffrey pines that grow on serpentine soils in the Klamath Range have chloroplasts that are genetically distinct from the Jeffrey pines that grow in the Sierra Nevada. I presented these exciting results in a poster at an international conference in Edmonton, Alberta, Canada.
When our mitochondrial and nuclear data are finished, I look forward to co-authoring a paper to submit for peer review! I will also give an oral presentation at the 100th annual Arkansas Academy of Science conference next spring, bringing my experience full circle - grant authorship, fieldwork, lab work, analysis, conference presentations, and, hopefully, a paper!

Student - Zach Nickell
Faculty Mentor - Dr. Matt Moran
Project Title - Effects of American Bison (Bison bison) Wallowing Behavior on the Arthropod Diversity of the Tallgrass Prairie
In the tallgrass prairies of North America, one of the most important organisms to the ecological health of the area is the American Bison (Bison bison). Bison affect the prairies by grazing on C4 grasses, which increases the diversity of plants, and by wallowing. Wallowing is a behavior where multiple Bison roll repeatedly on the same spot, creating a depression in the ground and killing off the vegetation. This depression collects more water than the surrounding areas, and different species of plants will grow in them in comparison to the surrounding area.
This summer, I worked on determining how the arthropod community of the wallows differed from the surrounding areas. I collected samples from the Tallgrass Prairie Reserve in Oklahoma from wallows and the surrounding areas. In the lab, I then removed all arthropods from each sample and sorted them based on morphospecies in order to determine the overall diversity and abundance in each sample. I have been compiling the data in order to compare the arthropod diversity of the wallows and of the normal prairie. I am currently working on sorting my samples from my latest collection trip, and I will finish compiling my data by December.

Student - John Pennington
Faculty Mentor - Dr. Andrea Duina
Project Title - A Genetic Approach to Elucidate the Role of the Tco89 Protein in the Regulation of Chromatin Function in Saccharomyces cerevisiae
In eukaryotic cells, nuclear DNA associates with various proteins to form a structure called chromatin. During chromatin formation, stretches of DNA wrap around histone octamers, which are composed of pairs of the histone proteins H2A, H2B, H3, and H4. The histone octamer with associated DNA is referred to as the nucleosome. The presence of nucleosomes greatly affects the process of transcription throughout an organism’s genome. In order for RNA Polymerase II (Pol II) to transcribe genes efficiently, nucleosomes must be manipulated in specific ways. Previous work performed in the laboratories of Dr. Fred Winston at Harvard Medical School and Dr. Andrea Duina at Hendrix College has identified a protein called Tco89 as a putative novel regulator of chromatin function and transcription elongation. Not much is known about the function of Tco89 besides that it is a component of the TORC1 complex, which regulates cell growth and division in response to nutrient availability.
My main project this summer included elucidating the putative nuclear functions of Tco89. I initially performed a genetic screen using a library of ~400 different histone H3 and H4 mutants to uncover potential genetic interactions between these histone mutants and a deletion of the TCO89 gene. This screen identified approximately 25 histone mutants that when combined with a tco89△ mutation appeared to cause lethality. Most of these mutants contained deletions in the N-terminal regions of H3 and H4, thereby possibly implicating these histone regions as being in some manner functionally related to the functions of Tco89. I am now in the process of retesting the synthetic lethal interactions we found in the screen by individually crossing the H3/H4 mutant strains with a tco89△ mutant strain and testing the phenotypes of the histone mutants in combination with a deletion of TCO89. These studies have the potential to uncover a novel role for Tco89 in the regulation of chromatin dynamics.

Student - Jacob Pierce
Faculty Mentor - Dr. Andrea Duina
Project Title - Characterization of a Nucleosomal Region Required for Proper Interactions Between the Transcription Elongation Factor Spt16 and Transcribed Genes
Our research group is studying the physical interaction between transcription factors and the nucleosome in yeast. Previous studies by our group have identified a region of the nucleosome required for proper interactions between the transcription factor Spt16 and histone proteins. My project aims to better characterize this region by analyzing the effects of mutations of individual histone residues. Based on the results of our studies, we will demonstrate the extent to which residues in this domain participate in physical interactions between histone proteins and Spt16. We hope to submit our findings for publication within a year. I presented a poster of our findings at the 2015 Central Arkansas Summer Undergraduate Research Symposium.

Student - Olivia Sims
Faculty Mentor - Dr. Jenn Dearolf
Project Title - Assessment of the Fiber-Type Profile and Myosin Heavy Chain Expression in the Neonatal Guinea Pig Rectus Thoracis
To combat neonatal respiratory problems, glucocorticoids are frequently given to pregnant mothers at risk of premature delivery (Fowden et al., 1998). My project is a continuation of related projects in the Dearolf lab that studied the effects of multi-course prenatal steroids on the development of guinea pig ventilatory muscles. Specifically, I am looking at the rectus thoracis, an accessory inspiratory muscle. I will determine the percentages and diameters of type IIA and IIX fibers in the rectus thoracis of neonatal (one day old) guinea pigs. I will also look at myosin heavy chain expression and citrate synthase activity in these muscles. By comparing the characteristics of the neonatal rectus thoracis to those of steroid treated fetal muscles, I will be able to determine if the administration of prenatal steroids accelerates fetal muscle development. If breathing muscle development is, in fact, accelerated without detrimental effects to the accessory ventilatory muscles, steroid-treated preterm infants would be just as equipped to handle times of respiratory distress as a full term infant.

Student - Jessa Thurman
Faculty Mentor - Dr. Maureen McClung
Project Title - On the Discovery of Gall Wasps
Parasitoid wasps are like parasites in their dependence on a host for survival, but a parasitoid will ultimately kill its host. These wasps will lay their larvae on an insect or a plant, then while the larvae develops, their host slowly dies. This relationship, although gruesome, has become very useful in recent years for combating a variety of invasive plants and animals. As a natural predator of only one host, these wasps can be released as biological control agents in an area where an invasive plant or insect has taken over. This technique works because once the invasive target species is annihilated, the wasp can no longer survive. However, before these wasps can be used, their ecological relationships must be documented.
I set out to do such documentation from June 22nd to July 29th, 2015, in the tropical cloud forest surrounding the University of Georgia's campus (UGA) in San Luis, Costa Rica. The project was a collaboration effort with the Smithsonian Museum of Natural History to discover new species of wasps in family Eurytomidae, a group of plant parasitoids. These wasps deposit their larvae in plants which form growths called galls (white arrow on photo) on the plant. I focused on collecting galls from plant family Myrtaceae (figs, myrtles, etc.) to document this unexplored relationship and ultimately build an arsenal of potential biological control agents, should any of these plants become invasive. Now that I have my collected wasps (bottom right photo), I will spend one week this December in Washington, D.C. with my supervisor, Dr. Mike Gates of the USDA to describe these wasps and compile my data for a taxonomic and ecological publication.
While I made great progress on documenting this plant-wasp relationship, I also developed personal field work experience, teaching techniques with the Hendrix in Costa Rica program, and was exposed to an entirely new culture. While at UGA, I was able to add to the campus' insect collections, assistant teach a class on comparative animal behavior, and meet more professional entomologists who specialize in my desired field of study. All of this was made possible through Odyssey which provided the majority of my funding for my six-week stay in the misty mountains of Costa Rica.
If you would like to know more about my adventures in Costa Rica, please take a look at my blog!

Student - Jarrett Wann
Faculty Mentor - Dr. Rick Murray
Project Title - The Role of the Dlk-1 Gene in the Developing Mouse Vomeronasal Organ
In our lab, we study the developing peripheral nervous system of mice. In particular, I study the developing vomeronasal organ (VNO for short), which is a small, tube-shaped organ located on either side of the nasal septum just above the roof of the mouth. Peripheral sensory neurons in this organ are exposed to the external environment and detect chemical signals including pheromones. These neurons send projections to the accessory olfactory bulb of the brain where they relay this sensory information. While some of the genes involved in the differentiation of neurons in the VNO have been characterized, little is known about the genetic regulation of its early development. It has been my job for the past two summers to investigate these mysteries and determine which genes are responsible for the development of the VNO.

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