College of Liberal Arts

University of Mississippi

Animal, Vegetable, or Cellular – Biology Theses Explore Our World

Animal, Vegetable, or Cellular.  This year’s University of Mississippi senior honors biology students investigated these topics and more in their thesis projects – intense bodies of research that were two years in the making.  From sharks, squirrels and songbirds to lettuce, fungi and brain cells, these students and their faculty advisers were immersed in a wide variety of interesting projects.

Martha Francis Dalton, working with biology professor Glenn Parsons, used a bite force gauge developed by Parsons to measure how hard sharks can bite and then examining the biological, ecological and environmental factors that alter that bite force.

As part of her research, which took her around the world, Dalton had the opportunity to see a couple of very large sharks up close, including a tiger shark and a great hammerhead shark. She was also part of a team that set a world record for tracking a great white shark during a summer internship in Africa.

Fascinated by sharks since her childhood, Dalton’s enthusiasm for the topic led her to choose it for her thesis. That childhood interest may turn out to be the impetus for a career.

“I am very glad that I was involved in an honors program that required I write a thesis involved in my field of study,” Dalton said. “It was very good exposure to the field of research biology, and I am now heavily considering applying to a graduate program to continue research in shark biology.”

Jonathan Hughes, working with biology instructor Carol Britson, studied the measurement of cell-packing density and size of calbindin-immunoreactive (CB-IR) GABAergic neurons in post-mortem brain samples of occipital cortex in major depressive disorder (MDD, or clinical depression) subjects. Hughes did his research at the University of Mississippi Medical Center in Jackson and at the University of North Carolina at Chapel Hill.

“To be brief, we wanted to determine whether there was an actual morphological difference between depressed and healthy patients in the actual cells using/producing this neurotransmitter, one subpopulation being calbindin-immunoreactive GABAergic nonpyramidal neurons,” Hughes said. “We found that this specific subpopulation of neurons was indeed significantly decreased in MDD patients by roughly 30 percent.”

Hughes’ research was published in Biological Psychiatry, and Hughes was listed as second author. The article can be viewed at: http://www.ncbi.nlm.nih.gov/pubmed/20004363.  He plans to pursue a career in the pharmaceutical industry, and he is now attending the University of Kentucky College of Pharmacy.

“This research has largely shaped my career outlook as I would like do research as well as practice pharmacy, specifically in this area,” he said. “The field of pharmacogenomics, the study of how a persons genetic blueprint affects how he/she responds to certain medications, is experiencing explosive growth right now. It is my hope that I could contribute research that would one day allow us to genotype depressed patients and determine what drugs would work best for them based on their genome, in essence treating the person, not the disease.”

Brittany Simpson, working with biology professor Elaine Day, tested the effects of the natural product Schizandrin, which purportedly reverses spatial memory impairments caused by the drug Scopolamine, to determine whether the natural product could potentially be used to treat Alzheimer’s disease. Her abstract was presented at the Society for Neuroscience in San Diego last year.

“Dr. Lainy Day and the rest of the Day lab guided me through the many problems and questions that come along with research, especially researching for the first time,” Simpson said. “Being able to obtain so much research experience has opened my eyes to the world of medicinal research, and made me want to continue to investigate diseases when I become a doctor.”

Simpson said she expects to have published three papers by the time she enters medical school in the fall at the University of Mississippi Medical Center.

Shelly Osborn and Kevin Randolph, working with biology professor Colin Jackson, both examined the presence of bacteria in salad greens. They used DNA methods to identify bacteria in lettuce, and they compared the numbers and types of bacteria found in both regular and organic varieties of the produce.  Osborn became interested in the topic after taking Jackson’s microbiology class.

“Food microbiology is a growing field due to outbreaks of food borne illnesses worldwide,” she said. “Because salad greens only have minimal processing, many of the bacteria associated with the plant are readily ingested upon consumption. I was really intrigued by this and wanted to better understand if these bacteria were primarily plant-associated, or if they could actually be linked to infections in humans.”

According to Osborn, the students’ work will help Jackson form a study that will eventually be published in a scientific journal. Osborn plans to attend the University of Mississippi Medical Center School of Dentistry in the fall.

“I feel like this project gave me a better understanding for the dedication and hard work that I will need to be able succeed,” she said.

Other biology students’ projects included:

Becky Brasher, working with biology professor Jason Hoeksema, analyzed the enzymatic properties of ectomychorrihizal fungi to determine what chemicals they can and cannot break down to determine their ecological and symbiotic functions.

Stephen Clark, working with biology professor Bradley Jones, analyzed the mechanisms and processes by which glial cell fate is determined over neuronal cell fate in neural progenitors.

Miles DeBardeleben, working with biology professor Richard Buchholz, examined variations within the Eastern grey squirrel related to parasitism.

Matthew DiGiusto, working with biology professor Elaine Day, studied whether the cerebellum plays a role in learning or producing song in songbirds.

 Filley Howe, working with biology professor Gary Gaston, spent three weeks in Belize researching the behavior of schoolmaster snapper. For her research, she swam daily to observe and record the fishes’ behavior and daily activities, resulting in a log of good, statistically significant data.

Robert Spencer Mills, working with biology professor Richard Buchholz, analyzed the correlation between parasite load and sexual signals that affect mate choice among mallards. Plumage quality and bills of mallard drakes will be measured relative to parasite samples in the organs.