British scientists claimed Wednesday to have
created human sperm from embryonic stem cells for the first time,
an accomplishment they say may someday help infertile men father
The technique could in 10 years allow researchers to use the
basic knowledge of how sperm develop to design treatments to enable
infertile men the chance to have biological children, said lead
researcher Karim Nayernia, of Newcastle University, whose team
earlier produced baby mice from sperm derived in a similar way.
The research, published in the journal Stem Cells and
Development, was conducted by scientists at Newcastle and the
NorthEast England Stem Cell Institute.
Stem cells can become any cell in the body, and scientists have
previously turned them into a variety of new entities, including
cells from the brain, pancreas, heart and blood vessels.
Some experts challenged the research, saying they weren't
convinced Nayernia and his colleagues had actually produced sperm
cells. Several critics also said the sperm cells they created were
"I am unconvinced from the data presented in this paper that
the cells produced by Professor Nayernia's group from embryonic
stem cells can be accurately called 'spermatazoa," said Allan
Pacey, a senior lecturer in andrology at the University of
Pacey said in a statement that the sperm created by Nayernia did
not have the specific shape, movement and function of real sperm.
Azim Surani, a professor of physiology and reproduction at the
University of Cambridge said the sperm produced by the Newcastle
team were "a long way from being authentic sperm cells."
Nayernia said the cells "showed all the characteristics of
sperm," but his group's intention was simply to "open up new
avenues of research" with their early findings, rather than using
the sperm to fertilize eggs.
Robin Lovell-Badge, a stem cell expert at the National Institute
of Medical Research said that despite the questions raised,
Nayernia and colleagues may have made some progress in obtaining
human sperm from embryonic cells.
Nayernia said creating embryos from lab-manufactured sperm is
banned by British law.
He said they only plan to produce sperm to study the reasons
behind infertility, and will not fertilize any eggs.
Some lawmakers said provisions should be made to allow sperm
derived from stem cells to be tested as part of potential fertility