Mice born from cloned sperm: Technique raises hopes for infertile men.

Cloning might one day restore the fertility of men with severely low sperm counts, say researchers in the United States who have cloned mouse sperm and used it to create apparently healthy adult mice. Embryologists at Cornell University's Weill Medical College in New York cloned the sperm using similar methods to those used to clone whole animals, most famously Dolly the sheep. They are hoping to clone human sperm within five years. If the technique works in humans, it could offer a lifeline to the roughly 1 in 300 men who are rendered effectively infertile by sperm counts approaching zero. "If we can find just three or four sperm in a sample, we could grow them up," says Gianpiero Palermo, who led the research with his colleague Takumi Takeuchi. **Far from perfect** Palermo and Takeuchi cloned mouse sperm by injecting the heads of sperm cells into eggs that had had their DNA removed. The resulting... Whole article: "http://www.nature.com":[ http://www.nature.com/news/2007/070702/full/070702-8.html]

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