Researchers have been able to describe the complete molecular process in a three-dimensional structure.
Researchers at the Swedish medical university Karolinska Institutet have created a 3D structure of how sperm binds to proteins in the extracellular coat of the egg, called zona pellucida (ZP).
The findings have important implications for human reproductive medicine, as they may explain how mutations in the sperm receptor gene could cause infertility. It could also potentially lead to the design of non-hormonal contraceptives specifically targeting egg-sperm interaction.
"The results give a remarkable picture of the female side of fertilization", said Luca Jovine, who led the study.
"But this is, of course, only half of the story. The next step will be to tackle the corresponding molecules on sperm that allow it to bind to the egg."
The results are published in the journal Cell.