Growth problems
Although most of the mice lived to adulthood, the animals were far from healthy, suffering from conditions ranging from breathing difficulties to growth problems.
Despite this, Prof Nayernia, who has just joined Newcastle University's stem cell research team, believes his work offers fresh hope for the 1.5million British men blighted by infertility. It could shed new light on the production of sperm in the body - or spermatogenesis - and even be used to boost the production of sperm in infertile men, including those left sterile by treatment for cancer.
The professor, who carried out the research while at Georg-August University in Gottingen, Germany, said: "This research is particularly important in helping us understand more about spermatogenesis, the biological process in which sperm in produced. We must know this if we are to get to the root of infertility.
"This knowledge could be translated into treatments for men whose sperm is dysfunctional, although this several years down the line."
The treatments - which are at least five years away - could include removing immature sperm cells from a man's testicles, growing them into fully-functional sperm in the lab, and then putting them back in the man's body.
Alternatively, identification of a common flaw in the sperm-making process could lead to the creation of a miracle pill to boost fertility. Other possibilities include creating sperm free from inherited genetic conditions and using cloning techniques to create sperm which is a perfect genetic match for an infertile man.
In time, similar techniques may be developed to treat infertile women.
The Newcastle researchers now want to try out the technique on cells gleaned from human embryos. However, ethical and safety concerns mean it is unlikely they will be allowed to use any sperm they manage to make to fertilise eggs and create embryos.
'Breakthrough'
British scientists described the latest research, which is published in the journal Developmental Biology, as a 'hugely significant breakthrough'.
The warned, however, that much more work is needed before the technique could be applied to humans.
Dr Allan (CORR) Pacey, a Sheffield University specialist in male fertility, said: "To be able to make functional sperm in the laboratory will be very useful to study the basic biology of sperm production.
"There are currently many things we don't know about how sperm are formed, let alone why it sometimes goes wrong and leads to infertility in some men. "It is more difficult to say whether artificial sperm produced in this way would ultimately be used as a new treatment for male infertility. There are many technical, ethical and safety issues to be confronted before this could even be considered."
Sheffield University colleague Professor Harry Moore said: "These processes in the test-tube are far from perfect as the mice were abnormal.
"We therefore have to be very cautious about using such techniques to treat men or women who are infertile until all safety aspects are resolved. This may take many years."
Critics say it is wrong to experiment on human embryos and question whether any flaws in the sperm will be passed down to future generations. Josephine Quintavalle (CORR), of Comment on Reproductive Ethics, said: "At this stage, things are going very wrong. The further you deviate from the norm, the more likely you are to create more problems than you bargained for."
Mike Judge, of the Christian Institute, said: "Any move that could potentially take fathers out of parenting is always something that could be worrying." |
