ERROR 1
ERROR 1
ERROR 2
ERROR 2
ERROR 2
ERROR 2
ERROR 2
Password and Confirm password must match.
If you have an ACS member number, please enter it here so we can link this account to your membership. (optional)
ERROR 2
ACS values your privacy. By submitting your information, you are gaining access to C&EN and subscribing to our weekly newsletter. We use the information you provide to make your reading experience better, and we will never sell your data to third party members.
Scientists know surprisingly little about the molecular mechanics of how sperm fertilize eggs; only three proteins central to the process have ever been identified, all in mammals. A study in Science reports that a tiny protein on the surface of zebrafish eggs acts as a species-specific gatekeeper for sperm, giving fertilization the green light only if the sperm is also from a zebrafish (2018, DOI: 10.1126/science.aat7113). Researchers in Andrea Pauli’s lab at the Research Institute of Molecular Pathology stumbled on the gene for this 80-amino-acid protein in a poorly understood region of the zebrafish genome. Zebrafish engineered to lack the gene produced eggs that couldn’t be fertilized by zebrafish sperm. The team used the gene-editing tool CRISPR to engineer zebrafish so their eggs expressed a homolog from a different fish called a medaka. Zebrafish sperm couldn’t fertilize the egg, but medaka sperm could. The researchers called the zebrafish protein Bouncer, a reference to a security guard at a bar. Such species specificity is crucial for animals like fish and frogs that release their sperm and eggs into the water for fertilization. Pauli’s team is now studying whether Bouncer’s mammalian homolog—a protein called SPACA4, which is expressed in sperm rather than eggs—is also involved in fertilization.
Join the conversation
Contact the reporter
Submit a Letter to the Editor for publication
Engage with us on X