The team found that three proteins on the sperm join to form a sort of key that unlocks the egg, allowing the sperm to attach. Their findings, published in the journal Cell, drawn from studies in zebrafish, mice, and human cells, show how this process has persisted over millions of years of evolution.

Scientists have discovered how a sperm and an egg fuse together, in a way that resembles a ‘lock and key’. New research focuses on the mechanism that connects the two types of cells across vertebrates in the animal kingdom.

AlphaFold predicted that three sperm proteins work together to form a complex. Two of these proteins were previously known to be important for fertility. Pauli and her colleagues then confirmed that the third is also critical for fertility in both zebrafish and mice, and that the three proteins interact with one another.

The researchers employed the artificial intelligence tool AlphaFold to uncover how sperm proteins interact at the molecular level.

Using Google’s AlphaFold, researchers identified the bundle of three sperm proteins that seem to make sexual reproduction possible.