A Sheffield fertility expert says new research in which scientists created early stage sperm from skin samples challenges the widely-held view that the ‘door is closed’ to infertile men who want children.
Dr Allan Pacey, a senior lecturer at Sheffield University, has welcomed the study, which raises the future prospect of laboratory-grown sperm allowing men to become fathers.
Scientists at Stanford University in the US took connective tissue from infertile men, which were then genetically engineered to transform them into embryonic stem cells.
The cells struggled to form sperm in a laboratory dish – but after being transplanted into mice, they turned into sperm cell ‘precursors’.
The findings indicate male infertility occurs relatively late in the maturing process of sperm.
Dr Pacey said: “The received wisdom is if you have a Y chromosome defect you don’t make sperm.
“Until I read this paper I would have said if you take skin cells from an infertile man it won’t work.
“However,what this seems to suggest is that it could.
“The fact they could do this at all is quite exciting – at the moment the door is closed to these men.
“As long as you’ve got enough of these cells, even for a short period of time, you might get sperm being produced.
“The same defect would be passed on, so any sons would have a risk of infertility, but there’s no other downside.”
Dr Pacey said the study also showed there was something ‘really interesting’ about sperm’s natural environment that was not fully understood.
He said: “There are chemical signals going on that we haven’t even scratched the surface of.”