By Jenny Hope
Last updated at 8:19 AM on 17th March 2011
Scientists have made a breakthrough that creates the possibility of a contraceptive pill not based on hormones.
They have tracked down the signal of ‘fertile attraction’ between egg and sperm.
Laboratory experiments show a hormone released by an egg ready to be fertilised acts as a ‘come hither’ message to sperm – which then reacts in less than a second.
The discovery, reported in the science journal Nature, means it may be possible to develop non-hormonal contraceptives to turn the signal off, thus replacing the Pill.
Researcher Polina Lishko and colleagues at the University of California, San Francisco, carried out experiments on mouse and human sperm to investigate how they detect an egg ready for fertilisation.
They measured the electrical currents that drive the wiggling movements of a sperm’s tail on its journey towards an egg newly released from the ovary.