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Mutants to the Rescue

Vaughn Cooper and high school students watch evolution in action.

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For Vaughn Cooper, a UNH associate professor in the molecular, cellular and biomedical field, evolution happens every day. In his world, organisms mutate, adapt and survive—or not—in a matter of hours or days, as opposed to centuries.

"We are studying evolution in action," he says. "By observing large bacterial populations, we have enough genetic diversity to see changes as they happen. The goal is to gain a better understanding of the factors behind evolution, and to clear up misconceptions. Currently, many perceive evolution as slow and mysterious, but that is not always the case."

For some, evolution is the science that evaluates why flightless birds came to be, or why a lizard that changes color is a successful mutant. In Cooper's studies, evolution holds the keys to battling disease. "If we can learn how to keep dangerous bacteria from adapting, spreading and causing chronic infection, then we can control many diseases, or the side effects from them," he says. "For example, we might be able to keep people with cystic fibrosis from developing chronic pulmonary infections. If we can understand what environments or genetic factors limit a bacteria's ability to survive, then tremendous strides can be made in preventing a number of illnesses."

Vaughn Cooper Vaughn Cooper, far right, associate professor in molecular, cellular and biomedical sciences, studies bacteria to see if the spread of disease can be prevented. He works with high school students, including (from left) Greta Gadbois, Kristen Dowling, Gabbie Bergeron and Cody Fitzgerald, encouraging them to pursue biotechnology.

Cooper has received a $1 million grant from the prestigious National Science Foundation (NSF) to explore how adaptations proceed, and how new mutations may benefit organisms in both their current environments and new environments.

Cooper explains that evolution by natural selection requires only that there be genetic diversity, and that this diversity is related to the ability to reproduce, or "fitness." "We are working with two very different types of bacteria--E. coli and Burkholderia," he says. "In large bacterial populations, genetic diversity is always present. Even if you start with a single cell, in the course of a day, you will have genetic diversity. You will go from a population of one to more than one billion in 24 hours."

The question then becomes, how do you measure fitness and how do you find new adaptive mutants? Cooper and his colleagues have figured out how to test for this by marking the bacterial populations with fluorescent proteins. Half of the bacterial populations are marked with red proteins and half with green. Intriguingly, a majority of the population always becomes dominant by the end of the day. "Even if you start 50-50, within a few days, you'll see roughly 80 percent green and 20 percent red," says Cooper. "The green fraction has picked up a mutation that allows it to grow better, showing that the 'more fit' bacteria has a stronger capacity for survival."

Cooper and his team have been growing the bacteria not just in liquids, but also on plastic and glass surfaces, forming biofilms. In this media, they have seen that the bacterial colonies look much different on auger plates, even to the naked eye. "Some are studded, some are ruffled, some are wrinkly," he says. "We don't know what has been altered in the DNA but something has. And this factor can be passed on to the mutant offspring."

Working alongside Cooper are high school students from several area schools. "One of my goals has always been to encourage high school students who are interested in biotechnology," says Cooper. "I wanted them to experience research and lab work firsthand, and this project lends itself to that kind of program."

The program began several years ago when Cooper formed a partnership with the Seacoast School of Technology in Exeter, NH. The school's faculty recommended several students who wanted to pursue studies in biology, and a partnership was born. Since then, the partnership has expanded to include students from Milford High School and Somersworth High School in New Hampshire and Amesbury, Massachusetts.

The students work full days in the lab and help mark bacteria, plate cultures in petri dishes, measure fitness, and evaluate what happens to "good mutants" when they are placed in new environments. Will the mutants adapt and thrive, or will there be a trade-off? Will they lose their ability to grow better in the environments where they started? Cooper also encourages the students to come up with their own ideas for experiments, and has implemented some of them. "One student wondered what would happen if the amount of iron in the bacteria-growing media was altered," he says. "This was an important question because we had noticed in previous experiments that some bacteria had evolved to absorb iron better. If the concentration of iron is altered, would that affect their evolution? We will find out."

Gabrielle Bergeron, a recent graduate of Exeter High School, has just spent her first year working with Cooper. In the fall, she will be studying biotechnology at Plymouth State College. "I like how much hands-on work there is," she say. "I love working in the lab and learning how a real lab operates. I feel like I've received good preparation for my career, and I'm gatherng key data at the same time."

Charles Traverse, now a UNH graduate student majoring in microbiology, has been with Cooper for six years, starting the summer after his junior year of high school. "In the beginning, I was fascinated just by the science, by gathering the information," he says. "I liked getting to use this equipment. Later, it became more about being part of something. Knowing that I was contributing to an important project has meant a lot."

Traverse feels his lab experience as a high school student and undergrad has definitely aided him in his college career. "I was almost a year ahead in some of my college science classes because of my work in the lab," he says. "When I entered the graduate program, I was already an experienced researcher. The whole experience has been invaluable to me, and I hope other students are able to take advantage of the same opportunity."

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