Sperm claims under the microscope
Updated on 08 July 2009
Channel 4 News examines the reaction to claims that sperm have been created from stem cells in a Newcastle laboratory.
Dr Allan Pacey, senior lecturer in andrology, university of Sheffield, said: "As a sperm biologist of 20 years experience, 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 ‘spermatozoa’.
"Whilst the cells produced may possess some of the distinctive genetic features and molecular markers seen in sperm, fully differentiated human spermatozoa have specific cellular morphology, behaviour and function that are not described here.
"The video clip does not have sufficient resolution for me to observe how these cells are moving, and since motility is an important part of sperm behaviour, it would seem important to assess this in some detail.
"Furthermore, because the structural elements of spermatozoa are very distinctive, I would need to see thin sections of the putative sperm taken with an electron microscope and compare them to how we know the head, midpiece and tail of mature sperm are constructed.
"In spite of my perhaps negative comment, I am supportive of research efforts to try and make in vitro derived spermatozoa in the laboratory since, if it was ever successful, it could help us answer some important questions about how sperm are made and why some men are sub-fertile."
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Professor Azim Surani, professor of physiology and reproduction, at university of Cambridge, said: "These sperm-like cells made in a dish from embryonic stem cells are a long way from being authentic sperm cells. First, they need to test if a normal male pronucleus with appropriate chromosome numbers and without mutations can form when introduced into an animal egg; and there has to be evidence that theses sperm-like cells are properly reprogrammed with male-specific imprints, without which they cannot function properly in early embryos."
Dr Evan Harris MP, who tabled amendments to the 2008 Human Fertilisation and Embryology Bill on IVD gametes to seek to speed up their potential use in fertility treatment, said:
"While the Newcastle team is not seeking at present to use stem cell derived sperm as a treatment for infertility, it is clearly a possible future application.
"It is very sad that the recent human fertilisation and embryology act did not take the opportunity to provide a power for Parliament to approve clinical trials of stem cell (IV) derived sperm as a treatment for male infertility by regulations.
"Instead the actual use of these gametes, even when derived from adult stem cells where no embryo is used, in the treatment of infertile couples will require primary legislation.
"This makes it more difficult to attract funding for the application of this research despite the government always banging on about the importance translational research."
