Human Sperm Created in Lab

Scientists in the UK claim to have created human sperm from embryonic stem cells in a technique that could lead to better understanding of male infertility.

The work won't be used to create humans in a Petri dish, the scientists assured.

The stem cells were cultured in a medium containing a derivative of vitamin A called retinoic acid. The cells developed into what are called germline stem cells, then they divided, as they would normally, to produce fully mature sperm.

"This is an important development as it will allow researchers to study in detail how sperm forms and lead to a better understanding of infertility in men – why it happens and what is causing it," said Karim Nayernia at Newcastle University. "This understanding could help us develop new ways to help couples suffering infertility so they can have a child which is genetically their own."

The sperm "will not and cannot be used for fertility treatment," the researchers said in a statement.

"While we can understand that some people may have concerns, this does not mean that humans can be produced 'in a dish' and we have no intention of doing this," Nayernia said. "This work is a way of investigating why some people are infertile and the reasons behind it. If we have a better understanding of what's going on it could lead to new ways of treating infertility."

The work is published today in the journal Stem Cells and Development.