Chinese scientists make mouse sperm in lab

In a development that holds promise for infertile men, scientists have produced rudimentary mouse sperm from stem cells in the laboratory.

If the success of the technique could be extended to humans, doctors might someday be able to turn skin cells from a man into sperm that could pass along  his DNA to his offspring.

However, according to experts, the technology would need to overcome some hurdles first.

The research was reported by Chinese scientists in an article released yesterday by the journal Cell Stem Cell. The technique was now under test in monkeys, according to a senior author.

The email by Qi Zhou of the Chinese Academy of Sciences in Beijing said the research had "a long way to go" before it could be used for infertile men.

The scientists started with mouse embryonic stem cells, found in embryos capable of developing into any kind of cell in the body. The cells were exposed to chemicals in the lab to nudge them toward becoming sperm. While earlier research had also generated sperm precursors in this way, the precursors had to be transplanted into the testicles of mice to develop further.

According to experts, the new technique marked an advance as it eliminated the need for transplants. Instead, sperm precursors are placed in a lab dish containing testicle cells.

According to BBC News, creating sperm in the testes was the longest and most complex bodily processes, which typically took a month to complete in most mammals.

"I expect many think it is easy to make sperm, most men just sit there and make millions of the little blighters every hour," said Robin Lovell-Badge of the United Kingdom's Francis Crick Institute. "However, as this paper clearly shows, it is much more complex than this."

"Reproducing germ cell development in vitro has remained a central goal in both reproductive biology and reproductive medicine," said Jiahao Sha, co-author of the study. "We established a robust, stepwise approach that recapitulates the formation of functional sperm-like cells in a dish. We think that it holds tremendous promise for treating male infertility."