A new study led by researchers at the University of California, Berkeley, has revealed how the egg controls sperm entry. The findings, published in the journal Current Biology, could lead to new methods of contraception and infertility treatments.

The researchers found that the egg releases a chemical signal that attracts sperm and then, once the sperm has reached the egg, the egg changes its chemical composition to prevent any other sperm from entering.

"This is the first time that we have been able to identify the specific chemical signal that the egg uses to attract sperm," said study lead author Dr. Polina Lishko. "This discovery could lead to the development of new contraceptives that target this signaling pathway."

The researchers believe that the egg's chemical signal could also be used to develop new infertility treatments. By mimicking the egg's chemical signal, it may be possible to attract sperm to the egg and help infertile couples conceive.

"This discovery opens up new avenues for research into contraception and infertility treatments," said study senior author Dr. Melissa O'Connor. "We are excited to explore the potential of this signaling pathway to develop new therapies."

The study was funded by the National Institutes of Health.