Study co-author and UNC postdoctoral researcher Dr. Yashwanth Radhakrishnan is exploring the evolutionary significance of defensin genes, how they evolved in the human genome. Numerous proteins similar in key attributes exist in different mammalian species, he said.

"We have already found homologues in monkeys, mouse and rat. The cluster of genes we're studying is 100 million years old," he said. "Do they have multiple functions or the same function? Are there differences in their mechanisms of action? Across species, we still have no data on function, or on what species of bacteria or viruses they kill. We hope to find some answers."

The Laboratories for Reproductive Biology, established more than 30 years ago, includes faculty in the departments of biochemistry and biophysics, cell and developmental biology, genetics, cell and molecular physiology, obstetrics and gynecology, and pediatrics. The LRB promotes understanding of normal and abnormal reproductive functions to discover new methods of treating infertility and develop new methods of fertility control.

LRB research is supported by grants from the National Institute of Child Health and Human Development, the NIH Fogarty International Center, the Contraceptive Research and Development Program, the Andrew W. Mellon Foundation and the Specialized Cooperative Centers Program in Reproduction Research at the NIH.

To view an image of the protein's effect on the bacteria, click on unc/news/newsserv/archives/may04/lrb050504.html