About the episode
Once the egg is fertilized by a sperm cell, the wall of the egg closes to prevent the entry of multiple sperm cells. Because if that happens, the exercise will be over.
Researchers now show in new research exactly how this process works. This can help in infertility research and treatment.
In mammals, fertilization begins when sperm cells attach to the wall of the egg. They have to work hard to squeeze through it. Once one sperm cell succeeds, the wall closes. But we still don't know everything about the wall structure and the proteins involved in this process.
Now we know a lot about the ZP2 protein in particular. This protein plays an important role in the interaction between the egg cell and the sperm. Once the first sperm cell enters the egg, this protein is broken down. This is what strengthens the wall. ZP2 was previously thought to be a sperm cell receptor, but this turns out not to be the case. They want to investigate further research into the protein that carries out this task.
Cleavage of ZP2 not only prevents multiple sperm cells from entering the egg, which will result in the egg not surviving, but is also important for protecting the later developing embryo.
The new knowledge can be used to explain some forms of infertility in women, where defects in the genes responsible for producing these types of proteins cause problems.
This may also make it possible to create non-hormonal pills that, for example, prevent the egg wall from closing.
Read more about the research here: A new discovery reveals how the egg controls the entry of sperm
