A team of researchers have managed to produce mouse sperm from stem cells in a laboratory.

It is thought that similar techniques could be used to help treat infertility in human males. If the scientists are proved right, human skin cells could be turned into sperm used to pass a man’s DNA to his offspring, writes Malcolm Ritter for The Washington Post.

Lab Mouse Sperm Technique Could Reduce Infertility

Chinese scientists make infertility breakthrough using mice

However experts have urged caution, claiming that there are a still a number of significant hurdles that must be overcome. The results of the research were published Thursday in the journal Cell Stem Cell.

The mouse work was carried out by a team of Chinese scientists, who are now working on using a similar technique on monkeys. Qi Zhou of the Chinese Academy of Sciences in Beijing said that the research has “a long way to go” before infertile men could benefit.

Mouse embryonic stem cells, which are found in embryos and develop into any kind of cell, were the starting point for researchers. The scientists used chemicals to encourage the stem cells to develop into sperm.

Sperm technique could help reduce infertility in human males

Previous research showed that these sperm precursors could be generated, but they then had to be moved into the mice testicles if they were to develop further. This latest research shows that testicles are not needed for the sperm to develop.

The researchers placed the sperm precursor in a lab dish which contained testicle cells, and watched as they developed far enough to fertilize eggs. However they never became fully mature sperm.

Over the course of the experiments the sperm were injected into 379 eggs, resulting in 9 baby mice. John Schimenti of Cornell University in Ithaca, New York, who was not involved in the work, claimed that the results were convincing.

Further research needed before technique can be applied to humans

He believes that the results could lead to major advances in our knowledge of sperm development. Both Schimenti and Renee Reijo Pera of Montana State University said that the technique could directly help infertile men in the future.

If the technique were to be used in humans it would involve skin cells or other cells that were later converted into stem cells. These stem cells, containing the individual’s DNA, would then be put through the process.

Reijo Para said that challenges would arise in using the technique in humans. One problem would be the need to find an alternative to using testicle cells from newborns.

Another hurdle is the fact that the results from mice need to be confirmed by other labs. This is standard process for scientific research. For the technique to be viable in humans the technique would have to become more efficient, given the limits on the availability of eggs from women.

Researchers reported that the work could lead to major advances. “All the offspring were healthy and fertile,” Professor Xiao-Yang Zhao, from the Chinese Academy of Sciences, told BBC News.

He went on to express his hope that the study would offer “inspiration” for human tissue work to “solve the problem of sterility.” At the same time he acknowledged the existence of “ethical concerns” and “possible risks should be ruled out first.”

Professor Jiahao Sha, from Nanjing Medical University, said: “We think that it holds tremendous promise for treating male infertility.”

Although sperm precursors have been used in the creation of healthy human babies in Japan, the procedure is illegal in other countries. Legal battles could become another obstacle.