Scientists have claimed success in growing immature sperm cells from bone marrow, which they hope to employ in fertility treatments within five years. Professor Karim Nayernia, and his team from the Universities of G?ttingen and the Medical School of Hanover, took stem cell samples from the bone marrow of male volunteers. Usually the samples would be developed into cells that form part of muscle tissue, but in this case the scientists induced them to develop into spermatogonial cells, which would ordinarily become mature sperm cells. The findings are published in Gamete Biology: Emerging Frontiers on Fertility and Contraceptive Development.

Professor Nayernia, now at the North-east England Stem Cell Institute, hopes that the process could be used to assist men rendered infertile by cancer treatment. He said: 'We are very excited about this discovery. Our next goal is to see if we can get the spermatogonial cells to progress to mature sperm in the laboratory and this should take around three to five years of experiments'.

The UK Government's proposed fertility white paper may prevent Professor Nayernia's goal being achieved, since it proposes a ban on using artificially created sperm or eggs in assisted reproduction. However, other scientists have expressed doubt over the research findings. Professor Henry Moore, of the Centre for Stem Cell Biology at the University of Sheffield, urged caution. He warned that manipulating stem cells could cause permanent genetic changes, making the sperm cells unsafe to use in fertility treatments. Professor Moore commented that 'this is a fast moving field but we are still many years away from developing any therapies for infertility using such techniques'.

Professor Nayernia also claimed to have evidence that it would be possible to grow sperm cells from female cells, stating that it had been possible to do so with mice. Professor Robin Lovell Badge, of the National Institute of Medical Research, London, discounted this claim, on the grounds that women's chromosomal makeup was incompatible with making sperm. Professor Lovell Badge also said that there were 'several misleading statements' in Professor Nayernia's paper. Josephine Quintavalle of Comment on Reproductive Ethics, CORE, said of the research paper: 'There is far too much hype in this paper. As to growing sperm from women? As any A-level biology student would question, "where are they going to get the Y chromosome from?"'

Reproduced from BioNews with permission, a web- and email-based source of news, information and comment on assisted reproduction and human genetics, published by Progress Educational Trust.