Sunday, May 27, 2012

Genetic discovery paves way for male contraception

When it comes to temporarily reducing fertility to prevent pregnancy, women always have to be the ones taking the contraceptives. Aside from 'neutral' ones like condoms, there are no real male contraceptives used in the same way as the women's 'pill', though there have been some rather unsuccessful attempts. That has something to do with the sheer amount of sperm cells that men produce: it is clear that preventing a single female egg from release is much easier than putting a stop to the sperm production in men, as they are produced by the billions. However, the discovery of a gene that plays a role in development of sperm might actually make male contraception a reality.

Scientists from the University of Edinburgh discovered that a gene called Katnal1 is essential for sperm cells to mature. Their development requires certain steps, and without functional Katnal1, the cells do not get to be fully functional units of reproduction. Because the gene functions rather late in development, the ability to produce sperm itself is left untouched. That should help with reversing the process, when having contraception is no longer desirable.

Studies have shown that by blocking activity of the gene, sperm maturation could be halted completely. A mutation in the Katnal1 gene, that rendered it dysfunctional, appeared to be enough to disrupt the maturation process in mice, but it is likely it works the same way in humans. They showed that without the support of Katnal1, developing sperm cells do not get the nutrients they need, hence arresting their development.

There are actually some contraceptives for males, even though they are not used much. Most of them work on the hormone level, which means it also disrupts other processes, making them not very desirable. Utilizing Katnal1, however, would mean making use of a non-hormonal drug to get the desired effect. Of course, that does mean that the scientists need to find a drug that stops it from working.

Katnal1 may be used as a base for new male contraceptives that function without touching the hormones that normally direct sperm production. By reversibly inhibiting the ability of sperm cells to mature, a contraceptive could function in the same way as the conventional contraceptive pill for women. Additionally, the scientists think their newfound insights in sperm development might help with new therapies to overcome infertility, because the way Katnal1 functions tells us something about the general process of sperm development.

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