For more than a century, scientists have studied the process of meiosis, the type of cell division that produces egg and sperm cells. But a full understanding of the process, which is known to play a key role in causing birth defects such as Down syndrome, has remained elusive.
A study from researchers at the Oklahoma Medical Research Foundation casts new light on the process. Led by Michael Dresser, M.D., Ph.D., OMRF researchers have discovered a new process in meiosis that appears to help prevent formation of abnormal chromosomes.
The research, which appears in the Proceedings of the National Academy of Sciences Online Early Edition this week, was performed in yeast. Because the genes involved in the process of cell division are similar in yeast and people, Dresser believes the experiments lay the foundation for further studies in humans.
“These findings open up a new area of research to understand how cells keep their chromosomes intact to avoid generating a range of genetic diseases,” said Dresser. “Because meiosis is similar in organisms from yeasts to humans, much of what is known about meiosis is discovered first in simpler organisms like yeast, plants, worms, fruit flies and mice, and then confirmed in humans.”
Meiosis is a central part of the reproductive process. In meiosis, 46 chromosomes come together, then are sorted into 23 pairs, ensuring that each sperm and egg contains the proper number of chromosomes.
At OMRF, Dresser’s research team, which also consists of Michael Conrad, Ph.D., Emma Lee and Joseph Wilkerson, discovered a new process in meiosis that appears to help prevent formation of abnormal chromosomes. This newly identified process functions by pulling apart chromosomes that are not supposed to interact.
“One of the genes required for this process is similar in yeast and humans, so there is a clear avenue for applying these findings to questions of human health and disease,” said Dresser. Scientists have long known that inheriting the wrong number of chromosomes can give rise to Down syndrome. More recently, said Dresser, “Researchers have discovered that children frequently inherit chromosomes with small bits that either are extra or missing, and these deficiencies can be related to health problems such as autism.”
Going forward, the OMRF researchers will study how the newly discovered meiotic process could play a role in causing—and, hopefully, preventing—chromosomal defects. “Now we have a new place to look when we try to understand situations where abnormal chromosomes are generated too frequently,” said Dresser. “Our goal will be to identify genetic or environmental factors that interfere with this process.”
This basic knowledge could ultimately lead to new methods for prevention of birth defects and the serious health problems they give rise to.
Dresser is an associate member of OMRF’s Molecular, Cell and Developmental Biology Research Program. He earned his B.A., M.D. and Ph.D. degrees from Duke University and joined OMRF’s scientific staff in 1989. His research focuses on chromosomal abnormalities that arise during the development of sperm and eggs.
This research project was supported by grants from the National Science Foundation and the Oklahoma Center for the Advancement of Science and Technology.
Chartered in 1946, OMRF (www.omrf.org) is an independent, nonprofit biomedical research institute dedicated to understanding and developing more effective treatments for human disease. Its scientists focus on such critical research areas as Alzheimer’s disease, cancer, lupus and cardiovascular disease. OMRF’s scientists, who include a member of the National Academy of Sciences and a Howard Hughes Medical Institute investigator, hold more than 500 U.S. and international patents.