LOW fertility and sterility could be explained by fresh insights into the way cells divide during reproduction.

Researchers at Edinburgh University have identified a gene that regulates a process essential to the formation of a healthy fertile egg.

This gene enables chromosomes – the thread-like structures inside all cells that contain our DNA – to huddle together. Scientists believe this huddling process is necessary to ensure the egg's healthy development and fertilisation.

The study, published in the Journal of Cell Science, looked at hundreds of infertile fruit flies in an attempt to unlock possible explanations for infertility in humans. The researchers found that without a gene known as SRPK, which is present in human and mammalian cells, chromosomes do not cluster. This then leads to sterility and low fertility.

Previous research in mice has shown this huddling process is essential in order for eggs to remain fertile.

Around one in six couples in Scotland may have difficulty conceiving. Infertility – being unable to conceive within a year of trying, or within six months if the woman is over 35 – is on the rise. In almost one-third of cases the cause is unexplained. For couples who have been trying to conceive for more than three years, the likelihood of pregnancy occurring within the next year is 25% or less.

By identifying the genes involved in the huddling process, experts now hope to be able to understand what goes on in the creation of fertile reproductive cells.