Is Protein Juno The Key to Understanding Fertilization?

The discovery of a protein vital to the complex dance that allows an egg and sperm to combine to form an embryo may lead to new options for fertility treatments.

Named for the Roman goddess of fertility, the newly discovered Juno protein is present on the surface of an egg cell. It binds with its counterpart on a sperm cell and starts the fertilization process.  This decade long search for Juno began in 2005 with the discovery of Izumo, the sperm protein counterpart. The discovery of Juno was recently published in the journal Nature by the Wellcome Trust Sanger Institute of Cambridgehshire.

Lab mice that were genetically engineered to produce eggs lacking the protein Juno were incapable of fertilization and findings suggest that Juno plays a critical role in fertilization.  According to the research, Juno may play an additional role in preventing multiple sperm cells from fertilizing the same egg.  Researchers are now trying to determine if the absence of the Juno protein can be linked to infertility in humans. If they can document the connection, it is possible that a simple genetic test could be developed that would identify those lacking in the protein.

“This research is helping us understand how fertilization occurs and may not occur at a cellular basis due to the presence of specific proteins that are expressed on sperm and egg cells.  It also helps us understand why multiple sperm cells are typically not able to penetrate one egg,” says Dr. Parviz Kavoussi, a board certified Reproductive Urologist and respected specialist in male fertility.  “This work is a great step for the understanding of the fertilization process and it may help direct specific treatments in the future.”

Because fertilization is not possible without the Juno protein, women who lack it would not benefit from a regular in vitro fertilization (IVF), which involves combining an egg with sperm in a lab. But, scientists believe that a form of IVF called intra-cytoplasmic sperm injection (ICSI) that entails injecting a sperm cell directly into an egg, may make fertilization possible. Further study of the Izumo-Juno connection may also offer new treatments for male infertility.

Considered a leader in the field of Reproductive Urology, Dr. Parviz Kavoussi is a multi-award-winning physician. Well-known for his respected research in the field of sexual medicine and male fertility, he served as the editor in chief of the first textbook focused on clinical urologic endocrinology. He sees patients at Austin Fertility and Reproductive Medicine/Westlake IVF, a prestigious private fertility center that is staffed by board certified specialists in both male and female fertility.

To schedule a personal infertility consultation with Dr. Parviz Kavoussi, contact Austin Fertility and Reproductive Medicine/Westlake IVF at (512) 444-1414.