Thanks to: The College of Arts and Sciences for financial support of the 2013 BIO SURP.

THE DEPARTMENT OF BIOLOGY AND

BAYLOR UNIVERSITY PRESENT

THE SUMMER UNDERGRADUATE RESEARCH PROGRAM

AUGUST 2, 2013 BAYLOR SCIENCES BUILDING A 207

2013 B I O S U R P

THE SUMMER UNDERGRADUATE RESEARCH

PROGRAM 9:15 INTRODUCTORY REMARKS 9:30 - 11:00 PRESENTATIONS

11:00 CONCLUDING REMARKS

PICTURES

11:30 LUNCH AT NINFA’S

SCHEDULE OF PRESENTATIONS 9:30 am David Crabtree 9:45 am Sam Groot 10:00 am Katherine Hooker 10:15 am Meredith Rosenthal 10:30 am Richard Vasquez

ABSTRACTS PROGRAM SCHEDULE

Richard Chun-Vasquez Mentor: Dr. Patrick Danley Hometown: Dallas, Texas Career goal: Medicine Major: Biology (2014) Interests: Breakdancing, basketball and music

Genetic basis for conspecific aggression in Lake Malawi cichlids Male-male competition is thought to play a critical role in the

evolutionary diversification of cichlid fish in Lake Malawi. This is because the evolution of novel characteristics is thought to provide a fitness benefit by reducing aggression toward conspecifics that are not recognized as competitors. Theoretical models assume a genetic basis to traits contributing to the diversification of species, yet no studies have demonstrated the genetic basis of male-male recognition in cichlid fish. In this study, we developed a phenotypic assay to measure the variation within and between individuals in their conspecific aggressive behavior in a hybrid cross between two territorial Lake Malawi cichlids, Maylandia zebra and Maylandia benetos. Through an analysis of this variation we measured the repeatability, an estimate of the heritability, of this behavior. In addition, we studied the transmission of male aggressive behavior through the F1 and F2 hybrids of M. zebra and M. benetos. The analysis of this behavior in the hybrids demonstrated that the F1 are intermediate to both parental behaviors. Furthermore, while most F2 are intermediate, the F2 are highly variable such that both parental phenotypes are observed. These results indicate that male conspecific aggressive behavior is genetically based and controlled by several genes. Using a standard quantitative genetic technique, we estimate the number of genes controlling this behavior to be less than 4. The phenotypic assay we developed represents a significant contribution to future studies of aggression in cichlids and other fish systems. This work is also the first demonstration of a genetic basis to the recognition of male competitors and suggests that male-male competition has the potential to drive the diversification of cichlid species.

ABSTRACTS ABSTRACTS

Meredith Rosenthal Mentor: Dr. Tamarah Adair Hometown: Grand Prairie, Texas Career goal: Medicine Major: Biology (2014) Favorite Tradition: playing Baylor Line during the last football game with the band

Variations of the effect of blue light on different strains of Staphylococcus aureus

Staphylococcus aureus infections are an increasing concern for the United States as it is currently the most prevalent cause of hospital acquired infections. The growing antibiotic resistance amongst these bacteria has called for new treatments, including photodynamic therapy, which uses light to kill microorganisms. We tested the variance of the response to blue light of 25 different isolates of S. aureus. Using 470 nm blue LEDs with an approximate forward power of 80 mW and an average luminance of 4.22 klux, we exposed 1 ml S. aureus cultures for 30 minutes and measured the optical density at 600 nm 18 hours after treatment. We compared the blue light treatment to a control group and found that there was a wide degree of variance with inhibition values ranging from 97% to an increased growth rate of 8%. Using flow cytometry, we measured cell counts at 4 hours after exposure to blue light for 3 strains identified as highly sensitive and 3 strains identified as highly resistant. There was a range of 80-99.9% inhibition when examining live cell counts. However, the discrepancy between the more and less sensitive strains was still apparent when examining live to dead cell ratios. A variation in susceptibility to blue light indicates a genetic trait may be responsible for this phenotype. Future studies will explore the genetic differences in these strains.

David Crabtree Mentor: Dr. Sanghoon Kang Hometown: Azle, Texas Career goal: Medicine Major: Biology (2014) Interests: Clarinet and Piano

Effects of Radio Frequency Electromagnetic Fields on the Human Skin Microflora

The prevalence of electromagnetic fields (EMFs) exerted by cell phones and other electronic devices has raised health concerns and initiated numerous research projects. One such health concern is unusual bacterial growth on the skin. Previous studies with different types of magnetic fields indicated that growth response is dependent upon the type of bacteria, which may cause a disruption of the normal flora and, thereby, impact human health. This preliminary experiment was performed to investigate the effects of cell phone radiation on bacterial growth by subjecting the normal flora of the human skin to the most common radio frequency (RF) EMFs emitted by cell phones, 2.4 GHz. Samples were taken from four individuals’ hand, chin and cheek and streaked onto plates, after which the most abundant colonies were further isolated with a maximum of three bacteria from each sample. The growth response was measured in 48-well plates under normal conditions and under high specific absorption rate (SAR) and low SAR RF-EMFs, a fifty percent reduction from high SAR, using a GloMax®-Multi Microplate Multimode reader (Promega). Isolation and growth were carried out at 37 °C. Bacterial growth was then analyzed graphically by comparing the growth rates of control and treatment based on error bars (standard error). Multiple samples’ growth rates were affected by the high SAR RF-EMFs, one of which had slowed growth and two of which showed enhanced growth. Low SAR caused only the growth rate of one sample to increase. Unaffected bacteria may have not had the appropriate intracellular reaction to alter growth rate. Further genomic and transcriptomic studies will provide more complete understanding and sufficient preliminary results for seeking external grants for cohort study.

ABSTRACTS ABSTRACTS

Sam Groot Mentor: Dr. Chris Kearney Hometown: Uxbridge, Massachusetts Career goal: Medicine Major: Biology (2014) Interests: Viola, fishing, and playing racquetball Development of a Cost-Effective RNA Nanoparticle to be used as a Malarial Vaccine

RNA viruses are potentially useful as vaccines through the stimulation of cellular and humoral immunity responses. One application of this would be to create an RNA viral vaccine against Malaria through the development of nanoparticles using the coat protein of Tobacco Mosaic Virus (TMV) and the single stranded (+)-sense RNA from Flock House Virus (FHV) RNA1. Using three separate Agrobacterium stocks modified with plasmids containing either B4 (RNA1 strand incorporating a Malarial antigen and the Origin of Assembly (Oa) for TMV coat protein), p19 (siRNA binding protein), or TMV coat protein, this experiment set out to develop a proof of principle experiment through the generation of humoral and cell-mediated immune reactions against GFP nanoparticles. Agroinoculation was done using syringes to inject agrobacterium into the leaves of the plant species Nicotiana benthaniama. Preliminary experiments using GFP instead of a Malarial antigen produced a plant extract that has been tested on mice and has shown a detectable level of antibodies towards GFP but no Interferon gamma (IFN�) differences, potentially indicating a lack of cytotoxic T cell activity. The goals of our current experiments are to optimize nanoparticle production. One test determined that a 2-step co-inoculation of B4 and p19 followed by TMV CP after four days produced a higher yield of nanoparticles than a 1-step co-inoculation of B4, p19, and TMV CP. Other experiments will determine the optimum concentration of Agrobacterium for GFP fluorescence. This observation should bode well in the future as we continue harvesting healthy leaves for nanoparticles purification.

Katherine Hooker Mentor: Dr. Ryan King Hometown: Abilene, Texas Career goal: PhD Aquatic Ecology Major: Biology (2014) Interests: BBB, greenhouse work, hammocking, slacklining, field work, being outside Nuclear Magnetic Resonance reveals effects of nutrient enrichment on leaf litter breakdown in Alaskan headwater streams

Headwater streams in Alaska’s Kenai Peninsula are important rearing habitats for juvenile salmon and are affected greatly by the surrounding landscape. Understanding more about this interaction will help with conservation efforts. In particular, the effect of nutrient inputs from the surrounding landscape may play a critical role on stream ecosystem processes, such as leaf litter breakdown. Recent studies have shown that alder, a woody plant that fixes atmospheric nitrogen, controls dissolved inorganic nitrogen availability in Alaskan headwater streams. I manipulated the nutrient content of grass litter packs in three headwater streams with varying levels of alder cover (none, low, and high) to experimentally test how nutrient limitation affects litter breakdown and change in organic matter chemical composition over time. Solid State Nuclear Magnetic Resonance was used to analyze the chemical compositional breakdown of the leaf litter. I found that the nutrient additions at the no alder site significantly increased grass litter breakdown and caused less selective breakdown of the litter by microbes. There was no significant change in breakdown rate or litter composition between the controls and nutrient infused leaf packs in the low alder and high alder sites indicating that organic matter processing at those streams was not nitrogen limited, and illustrating the strong influence of alder on a critical stream ecosystem process directly linked to production of juvenile salmon.