Student Profiles
Christina Paulson: 26, Biology
Christina Paulson had two lucky breaks while an undergraduate student at Tulane University in New Orleans: she broke her ankle and she graduated and left the city shortly before Katrina hit.
Yes, breaking her ankle was lucky. Paulson had been a dancer since she was a tiny girl in the farming town in southeastern Colorado where she’d grown up and was a dance major at Tulane (she teaches dance at a Dallas studio in her spare time these days). The injury, however, sidelined her from dance classes for a semester, and during that time she took biology courses and discovered a new love. “I think everything about biology is interesting. You can see it in everything around us. I’m just curious about what’s going on one step smaller than we can see,” Paulson says.
She’s even fascinated by worms, in particular a tiny nematode called C. elegans. The worm is one of the most useful creatures in the laboratory for a number of reasons, including the length of its life cycle, just three days.
Paulson and her advisor, Assistant Professor Jim Waddle, had the idea that the worm might be useful for laboratory toxicity screening. “You normally apply chemicals to individual cells or mice. We wanted to use worms because they’re a nice comprise. They tell us much more than cells, but they’re much cheaper and faster than mice.”
The problem with using worms to test drugs is that they are “filter feeders,” Paulson says. They live in the dirt and eat everything and excrete everything quickly, too quickly for toxins to have any effect. So Paulson doused the nematodes with mutagenic chemicals. Then she examined them, she examined hundreds, thousands, thousands more, looking for worms with abnormal intestines. Finally she had another lucky break. She found a worm that had outpouchings all along the intestine. Paulson and Waddle excitedly tested the mutant worm line and found that it did, indeed, show sensitivity to toxins. This line of mutant worms might some day be used by pharmaceutical companies to test new, better drugs to treat cancer or heart disease.
In the meantime, Paulson has continued to examine more worms that have been chemically treated and she has discovered three more with mutant intestines. “They have mutations in different genes, but all have weird intestines,” she says. “The hope is that we can figure out how these different genes relate to one another and figure out how this affects drug sensitivity.”
