Researchers found a protein that acts like Velcro to help sperm attach to eggs during fertilization is the same in roundworms and humans.
The study, led by Rutgers University in New Brunswick, NJ, is published in the journal Current Biology.
Senior author Andrew Singson, a professor of genetics who heads a laboratory in the Waksman Institute of Microbiology at Rutgers, says:
“Humans and worms are connected by a common ancestor that lived more than 700 million years ago and this discovery will give us insight into their shared genetics and fertility pathways.”
He and his colleagues identified a Velcro-like protein called SPE-45 in C. elegans worms that helps sperm bind to eggs during fertilization. The protein is the same as one discovered 10 years ago in humans by researchers in Japan who named it Izumo, after a Japanese shrine dedicated to marriage.
Prof. Singson says the new discovery suggests a common ancestor of worms and humans had an SPE-45/Izumo-like gene that was important for successful fertilization.
Finding suggests researchers can use worms to study human fertility
In their new study, the team found that roundworms lacking the SPE-45 protein produced sperm that looked normal but could not fertilize eggs. The problem was the same as that observed in the sperm of humans and other mammals that lacked the Izumo protein.
Finding this SPE-45/Izumo genetic connection between worms and humans means researchers can use worms to study Izumo functions in humans. This is much less difficult – in view of the ethical and experimental limitations – than using human subjects.
“The protein works like molecular Velcro and helps the sperm and egg bind and fuse,” explains Prof. Singson. “This type of finding can play an indispensable role in understanding the biological process.”
A separate paper by a team from Emory University in Georgia and Setsunan University in Japan published in the same journal corroborates the Rutger findings using a different approach.
In that study, the team compared and analyzed worm and human DNA sequences and created a hybrid SPE-45/Izumo molecule that can cure infertility in worms.
Prof. Singson says the results from the two groups validate each other and make the findings more solid. He concludes:
“Finding new fertility genes in the worm can help us further understand the molecular basis of human fertility. The end result of this knowledge could be more informed and effective treatments for human infertility and reliable contraceptives for both sexes.”
One in eight American couples have problems with fertility. In roughly two-thirds of cases, the problem can be found either in the man or the woman, but in around one third of cases, no explanation is found.
Meanwhile, from a recently published study of women in Bolivia, Medical News Today learned that roundworm infection can boost chances of pregnancy while infection by hookworm can reduce them. The researchers suggested the parasite infections exerted their influence via the immune system.