Erin O'Shea's first laboratory experience was the fruit of her strong will and resolve—a determination, that is, to avoid a summer of mowing lawns and painting houses as part of her family's contracting business. Instead of working alongside her four siblings in a small town in upstate New York, she opted to spend the summer after her freshman year in college research in a chemistry laboratory at Smith College. It was an experience that hooked O'Shea on laboratory research and motivated her to pursue a career in the biomedical sciences. "The experience made me realize how much fun real experiments can be," she said.

After graduating from Smith College with a bachelor's degree in biochemistry, O'Shea went on to receive a Ph.D. in chemistry from MIT—a degree she completed, amazingly, in only two and a half years.

Today, O'Shea's research focuses on the way cells sense changes in their environment and respond appropriately. "The ability of cells to survive relies on how well they can sense and respond to changes in their environment," explained O'Shea. Her work is contributing to scientists' understanding of human cell growth in cancer and other diseases.

Recent studies by O'Shea and her colleagues have shown that randomness in gene expression may lead to differences in cells—or perhaps even in people—that are genetically identical. Using yeast as their model, they found random noise affects gene expression in cells and that different promoters produce different amounts of noise. (The promoter is the segment of the gene that regulates its expression.) According to O'Shea, randomness in gene expression could have important evolutionary and biological implications. For example, mutations in genes could alter their "noisiness" independent of the effect of the mutation.

O'Shea and fellow HHMI investigator Jonathan S. Weissman have also published research measuring the abundance and pinpointing the cellular locations of more than 4,000 proteins in yeast. This line of research should be invaluable in helping researchers understand the complex biology of a relatively simple organism. "A major goal of genomics and proteomics is to understand the function of each protein, and important clues can be gleaned from where each protein is within a cell," she said.

With mentoring at the top of her list right now, O'Shea spends a lot of time with members of her lab. "I enjoy most watching people develop and become independent scientists," she said. "I hope the people in my lab experience the thrill of solving a new scientific problem, and I hope that they learn that the process can be just as satisfying as the actual finding."