THE GENETIC INVESTIGATOR
Biologist seeking to understand genetic changes over time

Evolutionary biologist David Pollock compares an automobile repair to the evolution of a gene, which drives the physical evolution of life on Earth.

“If you want to change a part on the surface of the car, that's easy, but if you want to change the water pump on the engine, that is more difficult because it is more integrated into the car,” says Pollock, an assistant professor in LSU's Department of Biological Sciences.

Like a car, a gene is multifaceted; different parts contribute differently to the overall operation, and understanding of these parts becomes increasingly complex the further you look under “the hood.” Despite these complexities and the multi-dimensional aspects of even a single gene, the basic aspects of translation from DNA to proteins are shared by organisms from the simplest bacteria to the most complex animals, including humans. Pollock is investigating the evolution of the parts of genes that provide instructions for the synthesis of proteins.

“Different parts of a protein will change at a different rate and in different ways depending on their structure and function,” says Pollock. “It is critical to understand this evolution.”

According to Pollock, understanding what genes have arisen or been lost, and how they have changed over time, can help us understand what it means to be human. These aspects of humanity, including such characteristics as live birth and whether or not humans are fur-covered or smooth-skinned, can be better explained through comparison of diverse organisms.

One experiment conducted by Pollock and his research team to test evolutionary hypotheses uses a basic life form: bacteria. The process involves exposing the bacteria to ultraviolet radiation then to blue light, which repairs the damage caused by the UV rays. This process allows them to observe the basic properties of genetic change as they relate to the structure and function of the protein responsible for this repair. One possible effect they may look for is how similar human proteins might be altered to provide this DNA repair function.

Having a firm grasp on the relationship between structure and function and developing tools to predict genetic change is critical to therapies that researchers might create to combat disease, or as Pollock refers to them, genetic mistakes.

“Why did humans get a certain disease and how? Sickle cell anemia and cystic fibrosis are single gene diseases that have been identified and are relatively easy to understand. Other diseases are more complex, and the many genes and mistakes that contribute to these diseases are much harder to identify. When we can identify the genetic mistakes that cause those diseases, we can develop ways to cure people afflicted by those diseases,” says Pollock.

Fighting disease and physical degeneration makes the study of the structure and function of genes and proteins of great importance. As the structures, functions, and interactions among all human genes become better understood, knowledge of these aspects can be applied to the aging process and more complex diseases such as heart disease, Parkinson's, and Alzheimer's, which continue to plague humans in the modern world.

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LSU Department of Biological Sciences

from Winter 2005