Student Research in Big PondGAMBIER, Ohio (October 5, 2007) A Kenyon associate professor of biology has received a federal grant to continue his lab group's research about how frogs process the toxic chemical dioxin.
The National Institutes of Health awarded Wade Powell $187,000 over three years. This is the third consecutive three-year grant Powell has received from the NIH for this project.
Powell and his students study the effects of dioxin on African clawed frogs. Researchers have a particular interest in these frogs because their embryos are often used as a model for vertebrate development. In addition, the embryos are used to test the toxicity of chemicals and environmental samples.
While dioxin is extremely toxic to humans and many other animals, Powell found in previous studies that the chemical does little harm to African clawed frogs, particularly early in their development.
The reason has to do with a critical protein found in these frogs and other vertebrates, including humans. This protein, called the aryl hydrocarbon receptor (AHR), binds dioxin in the body, the first step in a pathway causing the chemical's toxic effects.
In African clawed frogs, however, dioxins do not bind these receptors nearly as easily as they do in other animals. The question, Powell said, is why.
"In this new part of the grant, we are keying in on that receptor and trying to understand what makes it so different in these frogs," he said. For example, Powell and his students will make changes in the frog AHRs to see if they can make them bind more easily with dioxins.
Researchers also don't know much about the role of these receptors, and Powell aims to learn more about their function, and which chemicals within the body work with AHRs.
"One of our goals is to identify key features of the receptor, which would allow us to predict which animals will be sensitive or insensitive to dioxins," he said.
The new NIH grant will support the purchase of lab equipment and supplies, pay student summer stipends, and enable students to travel and present their results at national and international scientific meetings.