Breeding sperm for infertile men

With only 3 or 4 sperms, scientists can duplicate countless enough to help infertile men have children. This prospect is wide open after success on the mouse.

The team at the Weill School of Medicine, Cornell University in New York, USA cloned the mouse sperm in the same way as Dolly sheep. With the sperm produced, they created adult mice that looked very healthy.

The group hopes that human sperm cloning will become a reality in the next 5 years. If this technique is successful, it will bring happiness to men, because nearly one in every 300 men has nearly zero sperm density.

(Photo: Corbis.com) "If we find only 3 or 4 sperm in each sample, we can multiply them," said Gianpiero Palermo, the lead researcher.

Palermo and colleagues cloned the sperm of the mouse by injecting the head of the sperm (removing the tail) into the eggs that removed the DNA. As a result, " fake sperm " have begun to multiply, creating a group of cells that contain the same genetic material as the original sperm.

Next, they use these cells to fertilize intact mouse eggs. Finally, the embryos are transferred to the mother's uterus. So far, 13 mice have been born from this technique, of which four adults grow up and reproduce themselves.

However, research still takes a long time to complete, Palermo admits. In addition, the team is still not sure whether this technique is effective with human sperm, because the division of human cells is more complex. Palermo also predicts that each sperm can replicate no more than 8 times.

After all, the cloned sperms are spherical. Losing the tail (which helps normal sperm swim) makes them only suitable for IVF.

T. An