The Secret Behind Baby-Making? A Protein Named 'Juno,' Which Attaches Sperm And Egg – And Bingo!

Thanks to a recent study published in Nature, conceiving babies may get a whole lot easier. A group of researchers at the Wellcome Trust Sanger Institute, a genome research institute in the UK, have discovered that eggs appear to carry a special protein receptor that allows a sperm to attach itself and fertilize the egg.

Back in 2005, Japanese researchers discovered a protein receptor on sperm cells' backs. Now that this new group of researchers have discovered the counterpart protein, scientists in the future can now better understand the process of fertilization and how the two protein receptors on sperm and egg function together.

The sperm protein receptor had already been named "Izumo1" — Izumo after a well-known Shinto shrine dedicated to Okuninushi, the god of marriage. The U.K. researchers have therefore decided to name the egg's protein receptor "Juno," which is the name of the Roman goddess of fertility and marriage.

Researchers carried out the studies on mice. Once they discovered that there appeared to be a protein receptor on the eggs, they developed female mice that didn't have the Juno receptor. Those mice were unable to have their eggs fertilized, and sperm cells could not attach themselves. Conclusion: The Izumo and the Juno proteins were both necessary for fertilization.

Scientists also discovered this: 40 minutes after conception, the fertilized egg got rid of its Juno receptor. This is a discovery that might further explain why conceived eggs can block other sperm cells from getting through the cell walls. Once one Izumo attaches itself to Juno, no other Izumos can get in the way.

While this study was conducted on mice, the results could spell a huge change in fertility treatments for humans. Doctors can now examine women to see if their eggs have defects on their Juno receptors. If the women do have defects on their Juno receptors, doctors can then direct them to have intracytoplasmic sperm injection, or ICSI, which involves injecting a sperm cell directly into the egg. In this way, doctors can avoid subjecting the women to other fertility treatments that wouldn't directly address the problem.