Mechanisms in roundworms may help solve issues in human fertility

Shown are a normal spindle in an egg cell (left) compared to a spindle after removal of the motor protein dynein (right).

Researchers at Northwestern have discovered a trait in roundworms that prevents errors in cell division, possibly leading to techniques that can treat infertility in humans. The study, led by associate professor of molecular biosciences Sadie Wignall, was published on March 29 and supported by the National Institutes of Health.

“Prior to our work, certain proteins were thought to be essential for cells to divide,” said Wignall. “However, when we removed these proteins, we were surprised to discover a previously hidden ‘backup’ mechanism that was able to kick in when the main proteins were missing. We uncovered something that other researchers missed because, if the major mechanism is in place, then you wouldn’t know that backup existed.”

Egg fertilization is an important process that leads to the rapid division of cells in the embryo. However, reproductive materials in humans need a precise amount of genetic material in order to create a functioning organism. Most cells in humans are able to divide without issues, but egg cells often come with extra complications that can lead to an imbalance of genetic material in the embryo. 

Scientists previously believed dynein and kinesin-12 (two motor proteins in the egg cells) were responsible for cell division. However, while testing egg cells in roundworms, the Northwestern researchers concluded that when the two specific protein structures were removed, a backup mechanism would allow for the division to take place. 

Learn more in Northwestern Now’s article “Roundworms’ egg cells have a backup plan.”