Aaron Severson, Ph.D., of Cleveland State University has been awarded a $349,200 grant from the National Institutes of Health to investigate the cellular machinery that impacts conception and how defects in this process can lead to infertility and diseases such as Down syndrome.

The three-year project will support research analyzing how a protein complex known as cohesin affects meiosis, the cellular process at the heart of sexual reproduction.

“Defects in meiosis have a profound impact on health,” said Dr. Severson, a member of CSU’s Center for Gene Regulation in Health and Disease and an assistant professor of Biological, Geological and Environmental Sciences. “At conception, approximately one in three human zygotes, created through the combination of the sperm and the egg, has abnormal chromosomal content, which is the leading known cause of miscarriages and birth defects.”

Preliminary results indicate that as women age, the cohesin needed for meiosis is weakened, according to Dr. Severson. “This could explain why infertility and incidents of chromosomal diseases such as Down syndrome increase as women get older,” he said.

To better understand the intricacies of meiosis, Dr. Severson is studying a microscopic roundworm called Caenorhabditis elegans. “Meiosis in humans is very similar to the process in these lowly worms, so they make good model organisms for analyzing chromosomal transfer,” he said.

Dr. Severson’s research could have implications far beyond reproductive health, because errors similar to those that disrupt meiosis also occur in many forms of cancer.

The Center for Gene Regulation in Health and Disease at CSU ranks among the leading gene research centers in the United States. With more than $15 million in funding from the National Institutes of Health, the National Science Foundation, the American Heart Association and other sources, the center is dedicated to improving our understanding of biological processes and how malfunctions of those processes result in various diseases, including heart disease, infectious disease and cancer.