Professor David Crowley and Eliana Tabares '07: Double-Teaming the Double Helix
by Stacey MacDonald '06

July, 2005—Dr. David Crowley, assistant professor of Biology, and Eliana Tabares ‘07 of Lowell, MA, are working together to uncover how cells maintain their genetic material.

Crowley and Tabares are particularly interested in how cells repair the DNA damage caused by ultraviolet light. Exposure to UV light causes the DNA of cells to chemically change, which can lead to mutations and cancers if the changes remain uncorrected. Fortunately, cells have protein-mediated repair systems in place to fix the damage caused by UV light.

“There has been an immense amount of research done on the protein repair systems in bacteria, such as E.coli,” Crowley states. “However, little research has been done on the unique group of microorganisms known as Archaea.” Under Crowley’s guidance, Tabares has been performing experiments to discover a new method to measure the different rates of DNA repair within the genome of Halobacterium, a specific type of Archaea.

Halobacterium are microorganisms that live in environments that reach ten times the salinity of sea water, such as the salt lakes of Utah. One of the mysteries that Crowley and Tabares are trying to solve is how these archaea perform the process of DNA repair within such a salty environment.

Because Archaea have more genetic similarity to humans than bacteria do, the findings from this project will also help experimenters understand more about human DNA repair mechanisms. Crowley explains, “When humans breathe oxygen, their body is absorbing toxic byproducts that change the chemistry of DNA molecules. The information we find out about the repair enzymes within Archaea, can be applied to learn more about our own systems of detoxification in the human body.

Tabares, originally from Colombia, moved to the United States in 2000. Since then, she has graduated from Lowell Catholic High School, where she worked hard to learn the English language. She is now continuing her education at Assumption as a Biology and Chemistry double major, demonstrating an impressive knowledge of scientific terms and concepts. After graduation, Tabares plans on attending dental school and participating in more scientific research. “Choosing Eliana for this position was a no-brainer. She continually demonstrates an interest in microbiology, exemplifies a good work ethic, and came with excellent recommendations from faculty,” Crowley states.

Dr. Crowley began his work with Archaea while attending Stanford University for his Ph.D. However, his work with UV repair began long before, when he was an undergraduate student at Holy Cross. During that time, he chose to work on a research project at UMass Medical School in Worcester under the direction of Dr. Michael Volkert. It was this experience, Crowley states, “that inspired me to want to work on research with undergraduate students.” He adds, “Research helps students decide what career path they want to take in their lives. I realized that my interest was in microbiology through my undergraduate research. I have my dream job here at Assumption being able to mentor and work with many gifted students, such as Eliana, just as Mike did for me."